Helmet display

• US 4,897,715 A
• Filed: 10/31/1988
• Issued: 01/30/1990
• Est. Priority Date: 10/31/1988
• Status: Expired due to Fees

• Current Assignee: Martin Marietta Corporation
• Original Assignee: General Electric Company
• Inventors: Beamon, William S. III
• Primary Examiner(s): Shepperd, John W.
• Assistant Examiner(s): Parker, Michael D.
• Application Number:
  US07/264,621
• Time in Patent Office: 456 Days
• Field of Search: 358/3, 358/53, 358/60, 358/63, 358/87, 358/88, 358/93, 358/103, 358/104, 358/199, 358/200, 358/206, 358/230, 358/240, 358/241, 358/113, 340/705, 350/6.5, 350/6.6
• US Class Current: 348/115
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: H04N 3/08 having a moving reflector
• CPC Class Codes: Y10S 359/90 Methods

Abstract

A helmet mountable display system includes separate optical paths for providing a respective image to the left and right eye of an observer for stereoscopic viewing. Each of a first and second plurality of spaced apart, substantially point light sources supply a respective group of modulated rays of light. The rays of each group are collimated by a respective input lens and the collimated rays from each input lens are directed so that their envelopes all intersect at the same point. A horizontal and a vertical deflecting surface are disposed on opposite sides of the intersection point. Electro-mechanical drivers move the surfaces which scan all the collimated rays. The scanned rays from each group are focused onto a respective screen by a respective output lens to form a raster scanned image. The screens are divided into a plurality of contiguous zones with a ray from each light source assigned to a corresponding zone, which reduces the vertical scan angle excursions required. Simultaneous scan lines from the rays are displayed in each zone on the screen which reduces the video bandwidth requirement of the system. The image from the screens is supplied to the inside surface of a visor from which it is reflected to a corresponding eye of the observer.

Claims

1. A helmet mountable display system for displaying a first raster-scanned image to an observer in response to a first plurality of light source means, each of the first plurality of light source means for supplying a respective first light signal having a respective first predetermined size, the display system comprising:

first input lens means having an input and an output, the input of the first input lens means optically coupled to the first plurality of light source means for receiving each first light signal, the first input lens means for providing a first collimated light pattern at the output of the first input lens means in response to each first light signal supplied to the input of the first input lens means;

a first deflecting surface moveable about a first axis, the first deflecting surface for deflecting the first collimated light pattern in a first direction along a first predetermined optical path;

a second deflecting surface moveable about a second axis and optically coupled to the first deflecting surface, the second deflecting surface for deflecting the deflected first collimated light pattern received from the first deflecting surface in a second direction along the first predetermined optical path;

first output lens means having an input and an output and optically coupled to receive the deflected first collimated light pattern deflected from the second deflecting surface, the first output lens means focusing the deflected first collimated light deflected from the second deflecting surface;

screen means optically coupled to the output of the first output lens means and disposed at the image plane of the first output lens means, the screen means for displaying the image of each of the first light signals and further for displaying a first raster scanned image when the first and second deflecting surfaces are moving in a predetermined pattern, the first raster scanned image having a first plurality of zones, each of the first plurality of zones scanned in response to a corresponding one of the first plurality of light source means; and

visor display means, the visor display means having a visor surface viewable by the observer, the visor surface optically coupled to the screen means for presenting the first raster displayed image to the observer.

2. The display system as in claim 1, further including relay lens means optically coupled between the screen means and the surface, the relay lens means visor for transporting the image from the screen means to the surface of the visor.

3. The display system as in claim 1, wherein the image of the first light signals is scannable in a predetermined raster, the first deflecting surface providing the vertical scan when oscillating about the first axis and the second deflecting surface providing the horizontal scan when oscillating about the second axis.

4. The display system as in claim 1, wherein the image of the first light signals is scannable in a predetermined raster, the first deflecting surface providing the horizontal scan when oscillating about the first axis and the second deflecting surface providing the vertical scan when oscillating about the second axis.

5. The display system as in claim 1, wherein the first plurality of light source means includes a respective first optical wave guide for each of the first plurality of light source means and further wherein an end of each of the first optical wave guide supplies the respective first light signal, the size of the end for determining the predetermined size of the corresponding light signal.

6. The display system as in claim 5, wherein the number of first optical wave guides is eight.

7. The display system as in claim 1, further including first redirecting means disposed in the optical path between the first input lens means and the first deflecting surface, the first redirecting means for redirecting the first collimated light pattern from the output of the first input lens means in a first predetermined direction onto the first deflecting surface for shortening the straight line optical path length from the first input lens means to the screen means.

8. The display system as in claim 5, wherein the combination of the first input and first output lens means provide a 1:

1 image ratio between the size of one of the first light signals and the image of the one of the first light signals on the screen means.

9. The display system as in claim 1, the display system further for displaying a second raster-scanned image in response to a second plurality of light source means, each of the second plurality of light source means for supplying a respective second light signal having a respective second predetermined size, the display system further comprising:

second input lens means having an input and an output, the input of the second input lens means optically coupled to the second plurality of light source means for receiving the second light signals, the second input lens means for providing a second collimated light pattern at the output of the second input lens means in response to the second light signals supplied to the input of the second input lens means; and

second output lens means having an input and an output and optically coupled to receive the deflected second collimated light pattern deflected from the second deflecting surface, the second output lens means for focusing the deflected second collimated light pattern deflected from the second deflecting surface;

wherein

the first deflecting surface further for deflecting the second collimated light pattern in a first direction along a second predetermined optical path,

the second deflecting surface further for deflecting the deflected second collimated light pattern received from the first deflecting surface in a second direction along the second predetermined optical path, and

the screen means further optically coupled to the output of the second output lens means, the screen means further for displaying the image of each of the second light signals and further for displaying a second raster scanned image when the first and second deflecting surfaces are oscillating, the second raster scanned image having a second plurality of zones, each of the second plurality of zones scanned in response to a corresponding one of the second plurality of light source means, and the visor surface further for presenting the second raster displayed image to the observer, wherein the first and second raster scanned images are presented to respective eyes of the observer so that the observer can perceive a stereoscopic image.

10. The display system as in claim 9, the helmet having a left and right hemisphere separated along a meridian and respectively corresponding to the left and right side of the observer wearing the helmet, wherein the first input lens means and the second output lens means are fixedly attached to the right hemisphere of the helmet, the second input lens means and the first output lens means are fixedly attached to the left hemisphere of the helmet, the first and second deflecting surfaces are fixedly attached to the helmet such that the first and second deflecting surfaces are disposed along the meridian, and the screen means fixedly attached to the helmet, the screen means including first and second display screens, the first display screen disposed on the side of the left hemisphere for presenting an image to the left eye of the observer and the second display screen disposed on the side of the right hemisphere for presenting an image to the right eye of the observer, the first and second input lens means disposed so that the first and second collimated light patterns cross each other while passing between the first and second deflecting surfaces such that the image from the first plurality of light source means is displayed on the first display screen and the image from the second plurality of light source means is displayed on the second display screen.

11. The display system as in claim 10, wherein the first and second display screens include a respective first and second rear projection screen, wherein the visor surface for displaying the image from the first and second rear projection screen.

12. The display system as in claim 10, further including second redirecting means disposed in the optical path between the second input lens means and the first deflecting surface, the second redirecting means for redirecting the collimated light pattern from the output of the second input lens means in a second predetermined direction onto the first deflecting surface for shortening the straight line optical path length from the second input lens means to the screen means.

13. A method for generating a raster scanned image from video information for defining the image, comprising:

modulating a respective light signal for each of a predetermined plurality of contiguous zones of the image in response to a respective predetermined portion of the video information for forming respective modulated light signals;

collimating the modulated light signals;

deflecting the collimated modulated light signals by a first moveable deflector surface in a first predetermined direction for forming first deflected light signals;

deflecting the first deflected light signals by a second moveable deflector surface in a second predetermined direction for forming second deflected light signals, respective ones of the second deflected light signals indicative of a respective predeterminedly positioned line for each of the zones; and

focusing the second deflected light signals,

wherein the focused second deflected light signals are representative of the raster scanned image.

14. The method as in claim 13, wherein the number of zones is eight.

15. The method as in claim 13, wherein the number of lines for each zone is equal and the step of deflecting the first deflected light signals further includes deflecting the first deflected light signals such that respective second deflected light signals scan a predeterminedly identified corresponding line for each of the zones.

16. The method as in claim 15, wherein the predeterminedly identified corresponding line includes sequential lines of each zone.

17. The method as in claim 16, further including the step of scanning a line in one direction and the next sequential line in the opposite direction.

18. The method as in claim 15, wherein the predeterminedly identified corresponding line includes sequential odd lines of each zone followed by sequential even lines of each zone.

19. Visual display apparatus for generating a raster scanned image from video information for defining the image, the raster scanned image having a plurality of contiguous zones, the apparatus comprising:

a plurality of light source means, each light source means for supplying a respective modulated light signal to a corresponding one of the plurality of contiguous zones, each light signal modulated in response to a respective predetermined portion of the video information;

collimation means having an input optically coupled to the plurality of light source means, the collimation means for providing collimated light signals;

a first deflecting surface, the first surface moveable about a first axis;

a second deflecting surface, the second surface moveable about a second axis; and

focusing means having an input optically coupled to the second deflecting surface for receiving collimated light signals deflected from the second deflecting surface, the focusing means for focusing the collimated light signals received from the second deflecting surface such that a respective focused light signal scans a corresponding zone of the plurality of contiguous zones,

the first deflecting surface coupled in optical flow communication with the collimation means so that the collimated light signals are incident on the first surface and further disposed with respect to the second deflecting surface such that collimated light signals incident on the first surface are deflected onto the second surface,

wherein the focused light signals from the focusing means are representative of the raster scanned image when the first and second surface are moving in a predetermined pattern.

20. The apparatus as in claim 19, wherein the first surface forms the horizontal scan and the second surface forms the vertical scan of the raster scanned image.

21. The apparatus as in claim 19, wherein the first surface forms the vertical scan and the second surface forms the horizontal scan of the raster scanned image.

22. The apparatus as in claim 19, further comprising a plurality of fiber optic light guides, each of the plurality of light guides coupled at one end to a respective one of the plurality of light source means for receiving a respective modulated light signal and the other end of the plurality of light guides for providing a respective modulated light signal to the collimating means.

23. The apparatus as in claim 22, wherein the plurality of light source means includes a respective laser.

24. The apparatus as in claim 22, wherein the plurality of light source means includes a respective red, blue and green light emitting diode.

25. The apparatus as in claim 24, wherein the plurality of light source means includes a respective red, green and two blue light emitting diodes.

26. The apparatus as in claim 22, wherein the collimating means and the focusing means respectively include convex-convex lens means.

27. The apparatus as in claim 19, wherein the plurality of light source means includes a first predetermined number of light sources for presenting a first raster scanned image to the right eye of an observer and further wherein the plurality of light source means includes a second predetermined number of light sources for presenting a second raster scanned image to the left eye of an observer, whereby a stereoscopic display may be viewed by the observer when both the first and second raster scanned image are presented to the observer.

28. The apparatus as in claim 27, further including a helmet having a visor display system wherein the first and second raster scanned image are presented to the observer when wearing the helmet from a surface of the visor display system.