Apparatus for a display system

• US 5,113,177 A
• Filed: 10/04/1988
• Issued: 05/12/1992
• Est. Priority Date: 10/04/1988
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc.
• Original Assignee: Alliedsignal Inc.
• Inventors: Cohen, Ricard L.
• Primary Examiner(s): Weldon, Ulysses
• Assistant Examiner(s): FATAHI YAR, MAHMOUD
• Application Number:
  US07/253,175
• Time in Patent Office: 1,316 Days
• Field of Search: 340/105, 340/980, 353/13, 353/14, 358/103, 358/104, 358/93, 358/250, 358/211, 358/225, 358/148, 358/183, 350/174, 350/145, 350/538, 250/213 VT
• US Class Current: 345/8
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: H04N 13/344 with head-mounted left-right displays

Abstract

A display system for enabling a pilot in an aircraft to simultaneously view an image of selected display information and a scene external to the aircraft during low visibility conditions, such as the night-time, is provided. An image intensifier tube is mounted on the side of a pilot'"'"'s helmet, preferably a Helmet Display system, so that the image sensed coincides with the pilot'"'"'s field of view. The image intensifier tube intensifies light from the external scene and outputs voltages representative of the scene to a converter. The output voltage is converted to a video signal having a format which is compatible to the display system in use. A Combining Circuit combines the compatible video signal with video signals from other display sources, such as instrumentation panel displays. The combined electrical signals are input to a display driver which drives the display system to cause the selected display information to be superimposed on the external scene viewed by the pilot.

Claims

1. Apparatus for use by a pilot in an aircraft for simultaneous viewing on a display of an image of a scene external to the aircraft and of an image of selected display information, said display being a helmet display having a visor on a helmet, said visor acting as a collimating combiner, comprising:

(a) collecting means mounted on said helmet and collecting light from an external field of view which coincides with the pilot'"'"'s field of view without interfering with said pilot'"'"'s field of view for collecting and intensifying light from the external scene and providing a voltage on an output representative of the external scene, said collecting means being an image intensifying tube which is a light intensifying tube from a night vision goggle modified by removing an eyepiece and adding a CCD sensor, said image intensifying tube including (1) an objective lens which collects light from said external scene and forms an inverted image, (2) electron generating means for generating an electron flow, at a plurality of points in said inverted image, as a function of light collected by said objective lens, (3) amplifying means for multiplying said electron flows to generate an amplified electron flow at each of said points, (4) light generating means for generating light from each of said amplified electron flows, (5) the CCD sensor receiving light from said light generating means and having a plurality of photosites, each photosite generating a charge dependent on said photosite'"'"'s exposure to light, and (6) inverting means for reinverting said inverted image disposed between said light generating means and said CCD sensor, for receiving light from said light generating means and outputting a reinverted image to said CCD sensor,

(b) converting means for converting said voltage to a first video signal,

(c) means for providing at least a second video signal,

(d) combining means for combining said first and second video signals and for providing a combined video signal,

(e) driving means responsive to said combined video signal for driving the display, and

(f) synchronizing means for synchronizing the display so that said converting means converts said voltage to a first video signal for combining with said second video signal by said combining means in time for said driving means to be responsive to said combined signal.

2. Apparatus as claimed in claim 1, wherein said combining means has a plurality of inputs to accept a plurality of display signals and a plurality of outputs to drive a plurality of displays.

3. Apparatus as claimed in claim 1, wherein said driving means comprises:

(a) a CRT,

(b) a first relay lens system,

(c) a fiber optic conduit, and

(d) a second relay lens system.

4. Display apparatus for displaying images of a scene external to an aircraft and selected display information comprising:

(a) an image intensifying tube of the type including a light intensifying tube from a night vision goggle modified by removing an eyepiece and adding a CCD sensor and which collects and intensifies light from the external scene and generates a corresponding voltage, said image intensifying tube including (1) an objective lens which collects light from said external scene and forms an inverted image, (2) a sensitive cathode which generates an electron flow at a plurality of points in said inverted image, said electron flows being dependent on light collected by said objective lens, (3) a microchannel multiplier which generates an amplified electron flow at each of said plurality of points, (4) a phosphor screen which generates light from each of said amplified electron flows, (5) the CCD sensor having a plurality of photosites, each photosite generating a charge dependent on said photosite'"'"'s exposure to light, and (6) fiber optic twister means for reinverting said inverted image disposed between said phosphor screen and said CCD sensor for receiving light from said light generating means and outputting a reinverted image to said CCD sensor,

(b) converting means for converting said voltage to a first video signal,

(c) means for providing at least a second video signal,

(d) combining means for combining said first video signal with said second video signal to form a combined video signal,

(e) driving means responsive to said combined video signal for driving said display, and

(f) synchronizing means for synchronizing the display so that said converting means converts said voltage to a first video signal for combining with said second video signal by said combining means in time for said driving means to be responsive to said combined signal.

5. Apparatus as claimed in claim 4, wherein said driving means comprises:

(a) a CRT,

(b) a first relay lens system,

(c) a fiber optic conduit, and

(d) a second relay lens system.