HEAD-UP DISPLAYS

• US 3,666,887 A
• Filed: 06/24/1970
• Issued: 05/30/1972
• Est. Priority Date: 06/29/1968
• Status: Expired due to Term

• Current Assignee: Michael H. Freeman
• Original Assignee: Michael H. Freeman
• Inventors: Freeman, Michael H.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Leibowitz, Barry
• Application Number:
  US06/836,048
• Time in Patent Office: 706 Days
• Field of Search: 178/6ND,7.85
• US Class Current: 348/115
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0154 with movable elements
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 2027/0198 System for aligning or maintaining alignment of an image in a predetermined direction
• 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 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

This invention relates to the provision of a head-up display system for use in vehicles such as aircraft or land vehicles. A head-up display system superimposes selected visual information on the field of view so that an observer can see not only the view but also the visual information without having to look down at a dial or the like. In the present system there is provided a source of light information signals and means for superimposing an image of the said signals on the field of view of the observer together with means for detecting any angular displacement of the superimposed image with respect to a predetermined position and for producing a control signal proportional to the displacement. Finally there is provided a means responsive to the control signal to adjust the orientation of the light information signals so that the position of the signals in the image viewed by the observer remains more or less constant.

Claims

1. A head-up display system for displaying information to an observer in a vehicle having a predetermined field of view from the vehicle comprising a source of light information signals mounted on the vehicle, means mounted on the observer for superimposing an image of said signals on the field of view of the observer by directing light carrying the signals to the observer, monitoring means mounted on the vehicle for detecting angular displacement of the superimposing means with respect to a predetermined axis and for producing a control signal indicative of such angular displacement, and means responsive to such control signal for adjusting the orientation of the light information signals so that the orientation of the signals in the image viewed by the observer remains substantially constant with respect to said predetermined axis, wherein the monitoring means for detecting angular displacement of the superimposing means for producing a control signal indicative thereof comprise means to direct a beam of radiation onto the superimposing means, means to receive radiation reflected from said beam by the superimposing means, and means to emit a control signal responsively to displacement of the reflected radiation.

2. A system as claimed in claim 1 wherein said beam of radiation is infra-red radiation.

3. A system as claimed in claim 1 comprising projection means mounted on the vehicle and adapted to project light from said source of light information signals towards said superimposing means, and wherein radiation from said beam of radiation reflected by the superimposing means travels through at least part of said projection means.

4. A system as claim in claim 1 wherein said beam of radiation is distinguishable from light emitted by said source of light information signals, and further comprising an optical element disposed in the light path between said source of light information signals and said superimposing means and adapted to act selectively on said light and said radiation so that light from said source of light information signals travels via said optical element to said superimposing means, and said radiation reflected by said superimposing means and received by said optical element travels therefrom along a path different from that between said element and said source of light information signals.

5. A system as claimed in claim 4 wherein said optical element is adapted to transmit light from said source of light information signals and to reflect radiation from said beam of radiation.

6. A head-up display apparatus for displaying information to an aircraft pilot superimposed on his line of sight forward of the aircraft, the apparatus comprising a cathode ray tube mounted on the aircraft and adapted to emit light information signals, a partial reflector plate adapted to be worn by the pilot so that he can look therethrough along his line of sight, a field lens and a collimating lens mounted on the aircraft and adapted to collimate the light information signals from the cathode ray tube and project them onto said plate when worn by the pilot so that the plate reflects the light towards the pilot'"'"''"'"'s eyes, who thereby sees an imaGe of light information signals superimposed on his line of sight and appearing at infinity, a source of radiation mounted on the aircraft, a lens to project a beam of radiation from said source towards said plate when worn by the pilot, a vidicon tube to receive radiation from said beam reflected by said plate and adapted to emit an output signal indicative of the position of the received radiation, a control unit to receive said output signal and to apply a control signal to a beam deflection plate of said cathode ray tube responsively to a displacement of the radiation received by said vidicon tube, thereby to adjust the orientation of the light information signals emitted by the cathode ray tube to compensate for a change in orientation of said partial reflector plate worn by the pilot.