System and method for adjusting the focal length of an image displayed to a simulator user - Patents.com

Abstract

A system and method for adjusting the focal length of an image is provided that adjusts the focal length of an image displayed to a user at a specified viewpoint of a simulator. A mirrored image may be generated for display on a screen at a specified viewpoint. A simulated distance may be determined from the specified viewpoint to an object in the image. Based on the simulated distance, a focal length of the image may be determined. Based on the simulated distance, a size of the simulated object may be determined. An adjuster may adjust the size of the object in the image based on the simulated size.

Description

[Technical field]

[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 279,566, filed November 15, 2021, which is incorporated by reference in its entirety.

[0002] The present invention relates generally to adjusting the focal length of an image displayed to a user at a specified viewpoint of a simulator. More specifically, the present invention provides a system and method for adjusting the distance between a screen and a mirror of a simulator based on a simulated distance between a specified viewpoint and an object of an image displayed on the screen and reflected on the mirror. An adjuster is provided for adjusting the distance between the screen and the mirror. [Background technology]

[0003] Advanced simulators (e.g., flight simulators) that train a user to operate a vehicle typically include a primary display that provides the user with an image depicting the environment around the vehicle. With reference to FIG. 1, the real-world image 12 on the primary display 4 is achieved by collimating light (e.g., an image) to the user 30, rendering the image at an infinity focus. For example, the focal length of the image may be greater than about 30 feet. A projector 6 projects the image 12 onto a screen 8, where the image is displayed to the user 30 (e.g., a pilot) as a reflection off of a mirror array 10. As shown in FIG. 1, the image 12 on the primary display 4 is displayed to the user as collimated light beams 14, as indicated by a first arrow 34, and viewed at a far focus. The collimated light beams 14 are approximately parallel to one another.

[0004] Some vehicles, including aircraft such as helicopters, have a window called a "chin window" that is positioned to allow the pilot to see downward from the aircraft, as shown by second arrow 36 in FIG. 1. The chin window may be located near the floor of the aircraft's cabin or cockpit. In some aircraft, the chin window is located in front of the aircraft's rudder pedals. Pilots can use the chin window to see a reference point or object (such as the ground) during takeoff, landing, and while the aircraft is hovering.

[0005] Some prior art simulators 2 include a chin display 20 that reproduces objects 16B that are visible outside the cockpit through a chin window 18. Known simulators typically use either a real image display system or a wide angle collimated (WAC) display system to display the image seen through the chin window.

[0006] The real image display system 20 uses a monitor or side projection screen 22 positioned in front of the simulator's lower window 18. A pilot or user 30 of the simulator views a real image display system image 24 through the lower window 18. The viewing distance of the simulated image 24 produced by the real image display system is about 6 feet to about 8 feet. The viewing distance is equal to the physical distance between a designated viewpoint 32 of the simulator 2 and the monitor or screen 22 of the real image display system 20. As will be appreciated by those skilled in the art, the designated viewpoint 32 represents the preferred or optimal position of the user's 30 eyes when within the simulator. The designated viewpoint is used when designing the simulator components to provide an optimal scenic image produced by the simulator for the user to view.

[0007] The real image display system 20 provides realistic depth cues as the simulator provides a simulation of flying at or below a simulated height 28 of approximately 10 feet above a simulated ground 26. The real image display system also provides a bright, clear image with a relatively wide field of view (FOV). However, known real image display systems 20 have several shortcomings, such as being incompatible with night vision goggles (NVGs) when focused to be compatible with the near infinity focus of the primary display 4. As will be appreciated, this prevents the simulator from being used to provide training for certain activities and some simulated conditions (such as night flight operations) and negatively limits the training possible with the prior art simulator 2.

[0008] Furthermore, as shown diagrammatically in Figure 1, object 16B in image 24 produced by real image display system 20 for viewing through lower window 18 will become misaligned with object 16A in collimated image 12 of primary display 4 as the user's head moves. This problem is shown diagrammatically in Figure 1, where the top of tree 16A displayed in the image on primary display 4 is horizontally offset from the bottom of the same tree 16B displayed in image 24 produced by real image display system 20.

[0009] Also, because real image display systems have a fixed focus and the primary display is at infinity focus, the user's eyes must adjust to a different focal length when the user looks out the lower window (indicated by second arrow 36) and then out the main window (indicated by first arrow 34). The change in focus adversely affects the realism of the simulator, causing discomfort to the user and leading to eye fatigue. Known real image display systems also provide unrealistic depth cues when the simulated aircraft is at a simulated height greater than about 10 feet above the simulated ground 26.

[0010] A WAC display system used as a chin display offers several advantages over a real image display system. For example, the image provided by the WAC display system is infinity-focused. When viewed through the simulator's chin display, the image provided by the WAC display system remains aligned with the image 12 on the primary display 4 while the user's head is moving. The WAC display system is compatible with NVGs, and the WAC display system can provide realistic depth cues when the simulated height of the simulated aircraft is greater than about 15 feet above the simulated ground. However, when the simulated height is less than about 10 feet, the image depth cues provided by the WAC display system are unrealistic. Another problem with known WAC display systems is that they have a relatively small horizontal viewing angle of less than about 25° and a relatively small vertical viewing angle of less than 15°. Other problems with the chin display system are limited brightness and that they are more expensive than the real image display system 20.

[0011] A major drawback of both types of traditional downward window displays is that they have a fixed focal length and can only be optimized for one viewing distance. For example, in a simulation in which an aircraft descends from a high-altitude hover (such as a simulated height of about 30 feet) to a landing, a real image display system with a viewing distance of about 6 feet to 8 feet would be unrealistic for the first 90% of the descent. Similarly, a downward window WAC display system would be unrealistic for the final portion of the descent from about 30 feet to a landing. Thus, traditional downward displays are inaccurate for a significant portion of a simulated landing or takeoff procedure. The visual errors described for real image and WAC display systems would cause a user to use either type of display to misjudge the rate of descent and altitude over the terrain, resulting in a hard landing and difficulty maintaining the hover position. These deficiencies create significant limitations in the realism and usefulness of traditional simulators.

[0012] Therefore, what is needed is a system and method for adjusting the focal length of a simulator image in real time. Summary of the Invention

[0013] One aspect of the present disclosure provides a system for adjusting a focal length of an image displayed to a user at a specified viewpoint, the system comprising: (1) a screen for displaying an image depicting an object, (2) a mirror spaced a variable distance from the screen for reflecting the image displayed by the screen to the specified viewpoint, and (3) an adjuster for adjusting the distance between the screen and the mirror.

[0014] In some embodiments, the system further includes a control system in communication with the adjuster, the control system causing the adjuster to: (a) determine a focal length of the image based on a simulated distance between a specified viewpoint and an object in the image; (b) determine a simulated size of the object based on the simulated distance; (c) generate instructions to the adjuster to adjust the distance between the screen and the mirror to achieve the focal length; and (d) adjust the size of the object in the image based on the determined simulated size.

[0015] The system may include one or more of the embodiments described above, and optionally, the control system further: (1) generates an image; and (2) determines a simulated size of the object.

[0016] In some embodiments, the screen is at least one of a liquid crystal display, an organic light emitting diode display, a liquid crystal on silicon display, a light emitting diode display, a quantum dot display, and a plasma display.

[0017] The system may include one or more of the embodiments described above, and in some embodiments the system further comprises a projector that projects an image onto a screen, the screen being one of a front projection screen and a rear projection screen.

[0018] In embodiments where the screen is a rear projection screen, the projector is positioned to project an image onto the rear of the screen, the front of which is directed towards the mirror, In this embodiment, the rear projection screen may be positioned at least partially between the mirror and the projector.

[0019] Alternatively, if the screen is a front projection screen, the projector is positioned to project the image onto the front of the screen, which is directed towards the mirror, In this embodiment, the projector may be positioned at least partially between the mirror and the front projection screen.

[0020] In one or more embodiments, the front surface of the screen that faces the mirror is convex.

[0021] Alternatively, the front surface of the cleaner has a shape that includes at least a portion of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof.

[0022] In some embodiments, the projector is at a fixed distance from the screen and the adjuster moves the screen and the projector.

[0023] In some embodiments, the adjuster comprises a motor that moves at least one of the screen and the mirror to adjust the distance.

[0024] In other embodiments, the mirror is fixed, or is a fixed distance from the designated viewpoint.

[0025] The system may include one or more of the preceding embodiments, and optionally, the screen is interconnected to a platform of the conditioner, the platform being movable.

[0026] The system may include any one or more of the preceding embodiments, optionally wherein the platform moves to adjust the distance between the screen and the mirror.

[0027] In some embodiments, the adjuster includes a stopper that prevents the screen from contacting the mirror.

[0028] In some embodiments, the distance between the screen and the mirror correlates to the focal length.

[0029] In some embodiments, the screen has a first position at a first distance from the mirror and a focal length at infinity.

[0030] Alternatively, in the first position, the light rays reflected from the mirror are substantially parallel.

[0031] In the second position, the screen is at a second distance from the mirror and the focal length is less than infinity. The first distance is greater than the second distance.

[0032] In some embodiments, the system includes one or more of the features described above, and optionally, the mirror is reflective and has a front surface directed toward the designated viewpoint and the screen, the front surface of the mirror having a shape that collimates light from the screen when the screen is a predetermined distance from the mirror.

[0033] The front surface of the mirror is optionally concave.

[0034] Alternatively, the front surface of the mirror has an adjustable shape.

[0035] Alternatively, the front surface of the mirror has a shape that includes at least a portion of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof.

[0036] The system may include any one or more of the preceding embodiments, and optionally the system is associated with a simulator, such as a flight simulator.

[0037] In some embodiments, the simulator is an aircraft simulator and includes a lower window disposed between a designated viewpoint and the mirror.

[0038] In at least one embodiment, the image displayed by the screen is visible to the user through a lower window.

[0039] Another aspect of the disclosure provides a control system for a simulator that adjusts a focal length of an image displayed to a user at a specified viewpoint of the simulator. The control system can include (1) a processor and (2) a memory that stores instructions executed by the processor. When the instructions are executed, the processor performs the following operations: (a) generating an image to be displayed by a screen positioned and oriented such that the image is reflected by a mirror toward the specified viewpoint; (b) determining a simulated distance from the specified viewpoint to an object in the image; (c) determining a focal length of the image based on the simulated distance; (d) determining a simulated size of the object based on the simulated distance; (e) generating instructions to an adjuster that adjusts the distance between the screen and the mirror to achieve the focal length; and (f) adjusting the size of the object in the image based on the determined simulated size.

[0040] Optionally, determining the simulated distance includes one or more of: (1) receiving a specified viewpoint position; (2) determining a simulated position of the object relative to the specified viewpoint; and (3) determining a distance between the specified viewpoint position and the simulated position of the object.

[0041] In some embodiments, the control system includes one or more of the preceding embodiments, wherein the distance between the screen and the mirror is correlated to the focal length.

[0042] In the first position, the screen is a first distance from the mirror and the focal length is infinity. In the second position, the screen is a second distance from the mirror and the focal length is less than infinity. The first distance is greater than the second distance.

[0043] The control system may include one or more of the preceding embodiments, and optionally the memory includes instructions for maintaining the screen in a first position at a first distance from the mirror if the simulated distance is greater than a predetermined threshold. In some cases, the predetermined threshold is about 30 feet. In other embodiments, the predetermined threshold is greater than 30 feet or less than 30 feet.

[0044] The control system may include one or more of the embodiments described above and may further include instructions to move the screen to a second position, a second distance from the mirror, when the simulated distance is less than a predetermined threshold.

[0045] In some embodiments, the simulator simulates an aircraft. The simulator optionally includes a lower window disposed between a designated viewpoint and the mirror such that an image displayed on the screen is visible to a user through the lower window.

[0046] Another aspect of the present disclosure is to provide a method for adjusting a focal length of an image at a specified viewpoint, the method including: (1) generating an image for display on a screen oriented such that the image is reflected by a mirror of a simulator to the specified viewpoint; (2) determining a simulated distance between the specified viewpoint and a simulated position of an object in the image; (3) determining a focal length of the image based on the simulated distance; (4) determining a simulated size of the object based on the simulated distance; (5) generating instructions to an adjuster that changes the distance between the screen and the mirror to achieve the focal length; and (6) adjusting the size of the object in the image based on the simulated size.

[0047] Optionally, the method may further include receiving a specified viewpoint position.

[0048] In some embodiments, the screen and mirror are associated with a simulator that simulates an aircraft.

[0049] The simulator optionally includes a lower window positioned between the designated viewpoint and the mirror.

[0050] In some embodiments, the image displayed by the screen is visible to the user through a lower window.

[0051] The method may include one or more of the preceding embodiments, and may further include maintaining the screen in a first position at a first distance from the mirror if the simulated distance is greater than a predetermined threshold, where in the first position the light rays reflected from the mirror are substantially parallel and the focal length of the image is at infinity.

[0052] In some examples, the predetermined threshold is about 30 feet. In other embodiments, the predetermined threshold is greater than 30 feet or less than 30 feet.

[0053] In some embodiments, the method further includes moving the screen to a second position that is a second distance from the mirror when the simulated distance is less than a predetermined threshold, where in the second position the light rays reflected from the mirror are not parallel and the image has a fixed focal length less than infinity.

[0054] The method may include any one or more of the preceding embodiments, and optionally includes moving the screen away from the mirror to a first position that is a first distance from the mirror when the simulated distance increases from less than a predetermined threshold to greater than a predetermined threshold.

[0055] Alternatively, the method may further include moving the screen toward the mirror to a second position when the simulated distance decreases from greater than a predetermined threshold to less than a predetermined threshold.

[0056] Yet another aspect is a flight simulator for students training to operate an aircraft, including (1) a first display system simulating a first view from a window of the aircraft, and (2) a variable collimation display system simulating a second view outside the aircraft as seen through a lower window disposed near the floor of the simulator's cabin. The first display system includes (a) a projector, (b) a first screen, and (c) a mirror array that reflects a first image to a designated viewpoint of the simulator, the projector operable to generate a first image that is displayed on the first screen. The variable collimation display system includes (i) a second screen that displays a second image, (ii) a mirror that reflects the second image from the second screen through the lower window to the designated viewpoint, and (iii) an adjuster that moves the second screen relative to the mirror.

[0057] In some embodiments, when the second screen is a first distance from the mirror, the second image is at an infinity focus. Optionally, when the second screen is a first distance from the mirror, the light rays reflected from the mirror are substantially parallel.

[0058] In at least one embodiment, the front surface of the second screen facing the mirror has a shape that includes at least some of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof.

[0059] Optionally, when the second screen is at a second distance from the mirror, the second image has a fixed focal length that is less than infinity, the second distance being less than the first distance.

[0060] The flight simulator may include one or more of the above-described embodiments, optionally with the mirror being a fixed distance from a specified viewpoint.

[0061] In some embodiments, the second screen is at least one of a liquid crystal display, an organic light emitting diode display, a liquid crystal on silicon display, a light emitting diode display, a quantum dot display, and a plasma display.

[0062] The flight simulator may include one or more of the preceding embodiments, and in some embodiments, the variable collimation display system further comprises a second projector that projects a second image onto a second screen, the second screen being one of a front projection screen and a rear projection screen.

[0063] In an embodiment in which the second screen is a rear projection screen, the second projector is positioned to project the second image onto the rear of the second screen, the front of which is directed towards the mirror, In this embodiment, the rear projection screen is at least partially disposed between the mirror and the second projector.

[0064] Alternatively, if the second screen is a front projection screen, the second projector is positioned to project the second image onto the front of the second screen, which is directed towards the mirror. In this embodiment, the second projector is positioned at least partially between the mirror and the front projection screen.

[0065] In some embodiments, the second projector is a fixed distance from the second screen, and the adjuster moves the second screen and the second projector.

[0066] In some embodiments, the adjuster comprises a motor that moves at least one of the second screen and the mirror to adjust the distance between the second screen and the mirror.

[0067] In other embodiments, the mirror is fixed.

[0068] The flight simulator may include one or more of the above-mentioned embodiments, and optionally, the second screen is interconnected to a platform of the adjustment device, the platform being movable.

[0069] The flight simulator may include one or more of the above-mentioned embodiments, and optionally, the platform moves to adjust the distance between the second screen and the mirror.

[0070] In some embodiments, the adjuster comprises a stopper that prevents the secondary screen from contacting the mirror.

[0071] In some embodiments, the distance from the second screen to the mirror correlates with the focal length.

[0072] In some embodiments, the flight simulator includes one or more of the aforementioned features, and optionally, the mirror has a reflective front surface facing the designated viewpoint and the secondary screen, the front surface of the mirror having a shape that collimates light from the secondary screen when the secondary screen is at a predetermined distance from the mirror.

[0073] The front surface of the mirror is optionally concave.

[0074] In some embodiments, the front surface of the mirror has a shape that includes at least a portion of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof.

[0075] Alternatively, the front surface of the mirror has an adjustable shape.

[0076] In some embodiments, the flight simulator includes one or more of the preceding embodiments, further comprising a control system in communication with the regulator.

[0077] Alternatively, the control system is operable to perform one or more of the following operations: (a) determining a focal length of the second image based on a simulated distance from a specified viewpoint to an object in the second image, (b) determining a simulated size of the object based on the simulated distance, (c) generating instructions to an adjuster that adjusts the distance between the second screen and the mirror to achieve the focal length, and (d) adjusting the size of the object in the second image based on the determined simulated size.

[0078] Alternatively, the control system further generates a second image.

[0079] The Summary is not intended to, and should not be construed as, representing the entire scope and scope of the disclosure. The disclosure is described in various levels of detail in the Summary, the accompanying drawings, and the Detailed Description, and the inclusion or absence of elements, components, etc. in this Summary is not intended to limit the scope of the disclosure. Additional aspects of the disclosure will become more apparent from the Detailed Description, particularly in conjunction with the drawings.

[0080] As used herein, the terms "at least one," "one or more," and "and / or" are open-ended expressions that are both conjunctive and alternative in nature. For example, the phrases "at least one of A, B, C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" respectively mean A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C, respectively.

[0081] As used herein, the term "a" or "an" refers to one or more of that entity. Thus, the terms "a" (or "an"), "one or more," and "at least one" can be used interchangeably herein.

[0082] Unless otherwise noted, all numerical values ​​expressing quantities, dimensions, conditions, proportions, ranges, and the like used in the specification and claims shall be understood to be modified in all instances by the word "about" or "approximately." Thus, unless otherwise noted, all numerical values ​​expressing quantities, dimensions, conditions, proportions, ranges, and the like used in the specification and claims may be increased or decreased by about 5% to obtain satisfactory results. Furthermore, if the meaning of the term "about" or "approximately" as used herein is not clear to one of ordinary skill in the art, the terms "about" and "approximately" will be interpreted to mean within plus or minus 5% of the stated value.

[0083] All ranges described herein may be reduced to any subrange or portion of the range, or to any value within the range, without departing from the invention. For example, the range "5-55" includes, but is not limited to, the subranges "5-20" and "17-54."

[0084] As used herein, "comprises," "including," "having," and variations thereof are meant to encompass the items listed thereafter, equivalents thereof, and additional items. Thus, "comprises," "including," "having," and variations thereof can be used interchangeably herein.

[0085] The term "means" as used herein is to be understood to be interpreted as broadly as possible pursuant to 35 U.S.C. 112(f). Accordingly, any claim containing the term "means" is intended to cover all structure, material, or acts described herein, and all equivalents thereof. Furthermore, structures, materials, or acts, and equivalents thereof, are intended to include all that are described in the Summary, Brief Description of the Drawings, Detailed Description, Abstract, and in the claims themselves.

[0086] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosed system and, together with the general description of the disclosure above and the detailed description of the drawings below, serve to explain principles of the disclosed systems and devices. [Brief description of the drawings]

[0087] [Figure 1] FIG. 1 is a schematic side view of a conventional simulator with a real image display system located on the outside of the lower window. [Diagram 2] FIG. 2 is a schematic side view of a simulator including a variable collimation display system according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is an isometric view of a portion of the simulator of FIG. [Figure 4A] FIG. 4A is a schematic side view of a variable collimation display system for a simulator according to an embodiment of the present disclosure. [Figure 4B] FIG. 4B is a schematic side view of a variable collimation display system of a simulator according to another embodiment of the present disclosure. [Figure 4C] FIG. 4C is a schematic side view of a variable collimation display system for a simulator according to some embodiments of the present disclosure. [Figure 5A] FIG. 5A is a schematic side view of the simulator of FIG. 2 at a first simulated height above ground. [Figure 5A] FIG. 5B is another schematic side view of the simulator of FIG. 2 when it is at a second simulated height above the ground that is less than the first simulated height. [Figure 6] FIG. 6 is a schematic diagram of a control system for adjusting the focal length of an image in accordance with some embodiments of the present disclosure. [Figure 7] FIG. 7 is a flow chart illustrating a method for adjusting the focal length of an image according to some embodiments of the present disclosure. [Figure 8] FIG. 8 is another flow chart that generally illustrates a method for determining a simulated distance in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0088] The drawings are not necessarily to scale (although in some cases they may be). In some cases, details not necessary for understanding the disclosure or that obscure other details may be omitted. Of course, it should be understood that the disclosure is not necessarily limited to the embodiments described herein. As will be appreciated, other embodiments are possible using one or more of the features described above or below, either alone or in combination. For example, it is contemplated that various features and devices illustrated and / or described with respect to one embodiment can be combined with or substituted for features or devices of other embodiments, regardless of whether such combination or substitution is specifically illustrated or described herein.

[0089] 2-6, a simulator 40 is shown generally with a variable collimation display system 62 according to an embodiment of the present disclosure. The variable collimation display system 62 may be referred to herein as a variable display or chin display. The variable display 62 is operable to adjust the focal length of an image 64 displayed to a user 30 (e.g., a student) at a designated viewpoint 32 of the simulator 40.

[0090] Referring to FIG. 2, a simulator 40 is shown diagrammatically with a variable collimation display system 62 according to an embodiment of the present disclosure. The simulator 40 may be an aircraft simulator for training a user 30 to operate an aircraft including a lower window 46. The aircraft may be a fixed-wing aircraft, a helicopter, a tilt rotor aircraft, or any other aircraft with a lower window. However, it will be understood that the variable collimation display system 62 may be used in simulators simulating the operation of any type of vehicle. Mobile equipment and vehicle simulators 40 of any size and type, including, for example, automobiles, trucks, trains, tracked vehicles (such as tanks and construction vehicles), watercraft, and spacecraft, may include a variable collimation display system 62 according to an embodiment of the present disclosure. The variable collimation display system may also be used in games or other systems where the focal length of an image displayed to a user may need to be adjusted or changed.

[0091] The simulator includes a primary display 48 operating in conjunction with a variable collimation display system 62. The primary display includes a projector 50 that projects an image 56 onto a screen 52. The image 56 is viewed by the user 30 as a reflection off of a mirror array 54. The image 56 on the primary display 48 appears to the user as a collimated beam of light 58 and is viewed at a far focus. The image 56 includes an object 60 that is in a position simulated to be outside the simulated cockpit and is viewed by the user as indicated by the first arrow 34. In the example of FIG. 2, the object 60 is a tree.

[0092] The image 56 (and object 60 displayed in the image) may be at an infinity focus, such as a focal length of greater than about 30 feet. Thus, the collimated light rays 58 of the image are nearly parallel to one another.

[0093] A variable collimation display system 62 projects another image 64 through the lower window 46 of the simulator 40. The image 64 is viewable by the user 30 through the lower window 46, as indicated generally by the second arrow 36.

[0094] The lower window 46 is disposed within the simulator 40 between the designated viewpoint 32 at which the user 30 is positioned and the mirror 74 of the variable collimation display system 62. The lower window 46 is typically located at or near the floor of the simulator 40 and is used by the user 30 during simulation of takeoff, landing, and / or hovering of the simulated aircraft. It will be appreciated that the variable collimation display system 62 may also be used during other simulated procedures.

[0095] The variable collimation system typically includes a mirror 74 and a screen 68. In some embodiments, the variable collimation display system 62 includes a projector 80 as shown in FIG. 2. The projector 80 and screen 68 may have different arrangements, as shown generally in FIG. 4B, in other embodiments described herein. Furthermore, in some embodiments of the present disclosure (e.g., as described in connection with FIG. 4C), the variable collimation system 62 does not include a separate projector 80, since the screen is self-illuminating. In use, the projector 80 (or screen 68) projects an image 64 that is viewed by the user 30 as a reflection of the mirror 74.

[0096] In all embodiments of the variable collimation display system 62, the image 64 is aligned with the image 56 of the primary display 48. Thus, as shown generally in Figure 2, the images 56, 64 of the primary display 48 and the tree 60 in the variable collimation display system 62 are aligned with one another from the perspective of the user 30 at a specified viewpoint. Additionally, a control system 122 in communication with the primary display 48 and the variable collimation display system 62 can change the simulated size 106 of the object 60 in the image as the simulated height 102 above the ground 26 of the aircraft changes (as shown generally in Figures 5A, 5B).

[0097] 3 illustrates generally some embodiments of a variable collimation display system 62 for the cockpit 42 of the simulator 40. The cockpit 42 may include a window 44 associated with a primary display 48. The variable collimation display system 62 is positioned to display an image 64 through a lower window 46. Although only one variable collimation display system 62 is shown, the simulator 40 may have a second variable collimation display system associated with a second lower window on the opposite side of the cockpit 42.

[0098] In some embodiments, the cockpit 42 can include an upper window 45. Alternatively, the simulator 40 can include a variable collimation display system associated with one or more of the upper windows 45. Additionally, the variable collimation display system can be associated with any window of the cockpit, such as a side window or a lower side window.

[0099] 4A-4C, an embodiment of a simulator 40 is illustrated generally with a variable collimation display system 62 of the present disclosure. In all embodiments, the variable collimation display system is operable to adjust or change the focal length of an image 64 displayed to a user 30 based on a simulated or perceived distance 100 (also referred to as "slant distance" or "line-of-sight distance") between the user's specified viewpoint 32 and an object 60 outside the simulated environment or simulated vehicle.

[0100] The variable collimation display system 62 includes a screen 68, a mirror 74, and an adjuster 82. The screen 68 is configured and operable to display an image 64. The mirror 74 is configured and operable to reflect the image displayed by the screen 68 to a designated viewpoint 32. Although the variable collimation display system is shown for use with the lower window 46, it will be understood that the variable collimation display system may be used for any display that is viewable through any window of the simulator and in any simulated environment.

[0101] The focal length of the variable collimation display system 62 is adjusted by an adjuster 82, which is operable to change a distance 96 between the screen 68 and the mirror 74. As the focal length is changed, a size or height 106 of the object 60 appearing in the image 64 displayed on the screen may be adjusted by a control system 122 of the simulator, as described herein. The control system 122 is in communication with the adjuster 82 and one or more components of the variable collimation display system, such as the projector 80.

[0102] Mirror 74 has a rear surface 76 and a front surface 78 opposite the rear surface. The mirror's front surface 78 faces the lower window and the front surface 72 of screen 68 and is adapted to reflect light from the screen to a designated viewpoint. In this manner, user 30 views image 64 at the reflective front surface 78 of mirror 74.

[0103] The mirror 74 and its front surface 78 may be any shape and size. For example, the mirror 74 may be curved or flat. In some embodiments, the mirror's front surface 78 has a shape that includes at least a portion of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof. In some embodiments, the front surface 78 may be described as generally concave.

[0104] The front surface 78 of the mirror is shaped to collimate light from the screen 68 when the screen is a predetermined distance from the mirror 74 .

[0105] Alternatively, the front surface of the mirror 78 is substantially rigid. Additionally or alternatively, the front surface of the mirror 78 may have an adjustable shape.

[0106] In some embodiments, mirror 74 may include multiple mirrors. In such embodiments, the multiple mirrors may include a combination of curved and / or flat mirrors.

[0107] In at least one embodiment, the mirror 74 is fixed relative to the lower window 46, and the screen 68 is moveable by an adjuster 82. In such an embodiment, the mirror 74 is a fixed distance from the designated viewpoint 32.

[0108] The adjuster 82 is configured and operable to change the distance 96 between the front surface 72 of the screen 68 and the front surface 78 of the mirror. Thus, the distance 96 is variable. The adjuster 82 may move the screen 68 in any manner known to one of ordinary skill in the art.

[0109] In some embodiments, the adjuster 82 includes a platform 84 that is movable relative to the mirror 74. More specifically, the platform can be moved toward or away from the mirror 74, as indicated generally by arrow 86.

[0110] Alternatively, in at least one embodiment, adjuster 82 moves screen 68 along the optical centerline (or optical axis) of mirror 74. However, in other embodiments, adjuster 82 may move screen 68 along a different axis relative to the mirror.

[0111] The screen 68 may be secured to a platform 84. Thus, the screen 68 moves with the platform 84 towards or away from the mirror 74, as indicated by arrow 86. Any suitable means of securing a screen to a platform known to one of ordinary skill in the art may be used with the convertible display 62 of the present disclosure. In some embodiments, the screen 68 is secured to the platform by a mount or stand 88.

[0112] Alternatively, the stand 88 is operable to change the orientation of the screen 68 relative to one or more of the platform 84 and mirror 74. In this manner, the orientation of the front surface 72 of the screen 68 may be changed as the platform 84 changes the distance 96 between the screen and the mirror. In some embodiments, the stand 88 is capable of rotating the screen about a vertical axis of the stand. Additionally or alternatively, the stand is capable of pivoting the screen relative to the vertical axis.

[0113] The adjuster 82 includes an actuator 92 that moves the platform 84. The actuator 92 can move the platform 84 toward or away from the mirror in response to signals from the control system 122. It will be understood that the adjuster 82 can move any component or any combination of components of the variable collimation display system 62.

[0114] The actuator may include any suitable means known to one of ordinary skill in the art operable to change the position of the platform 84 relative to the mirror. In some embodiments, the actuator 92 includes a motor. Additionally or alternatively, the actuator may include tracks, rails, wheels, gears, pistons, servo drives, worm drives, belts, cables, and the like. In some embodiments, the adjuster 82 may include a track along which the screen 68 moves or slides to adjust the distance 96.

[0115] In some embodiments, the adjuster 82 comprises a motor that moves the screen 68. It will be appreciated that the motor can move the mirror 74 and / or the projector 80.

[0116] In some embodiments, the adjuster 82 alternatively includes a stop 94. The stop 94 prevents the screen 68 from unintentionally or inadvertently contacting the mirror 74. For example, the stop 94 maintains a predetermined minimum distance 96 between the screen 68 and the mirror 74. In this manner, the stop 94 can prevent the screen 68 from contacting the mirror 74.

[0117] The stop 94 may be associated with the platform 84. Alternatively, the stop may be associated with the actuator 92. Other means for preventing the screen from moving less than a predetermined distance 96 from the mirror may be used with the variable collimation display system 62 of the present disclosure.

[0118] 4A and 4B, in some embodiments, variable collimation display system 62 also includes a projector 80 that projects image 64 onto screen 68A. In some embodiments, projector 80 has a lens with a fixed focal length. Alternatively, projector 80 may include optics such as one or more lenses and / or mirrors such that the focal length and / or the size of object 60 in image 64 can be adjusted.

[0119] The projector 80 may be secured to a platform 84. Thus, the projector 80 may move with the platform 84 as the platform adjusts the position of the screen 68A relative to the mirror 74. Any suitable means of securing the projector to a platform known to those of skill in the art may be used. In some embodiments, the projector 80 is secured to the platform by a mount 90.

[0120] In some embodiments, projector 80 is positioned a fixed distance 98 from screen 68A. Specifically, in some embodiments, distance 98 between the projector and screen does not change and is substantially constant. In these embodiments, adjuster 82 moves both screens 68A-1, 68A-2 and projector 80 substantially simultaneously.

[0121] Alternatively, in at least one embodiment, the distance 98 between the projector 80 and the screens 68A-1, 68A-2 may also be changed by the adjuster 82.

[0122] Screen 68A may have any shape. In some embodiments, the screen may be curved or flat. A rear surface 70 of screen 68A may be concave and an opposing front surface 72 may be convex. In some embodiments, screens 68A-1, 68A-2, and 68B have shapes that include at least a portion of a circle, a sphere, a parabola, an ellipse, a plane, a freeform, and combinations thereof.

[0123] In embodiments in which variable collimation display system 62 includes projector 80, screen 68A may be a rear projection screen 68A-1 (shown in FIG. 4A) or a front projection screen 68A-2 (shown in FIG. 4B).

[0124] 4A, in an embodiment in which screen 68A-1 is a rear projection screen, projector 80 is positioned to project image 64 onto rear surface 70 of screen 68A-1. Image 64 appears on front surface 72 of screen 68A-1 and is then reflected by front surface 78 of a mirror.

[0125] In some embodiments, the screen 68A-1 is formed of a transparent or substantially transparent material. For example, the screen 68A-1 may be acrylic or glass. Optionally, the screen 68A-1 is treated to diffuse light from the projector 80. In some embodiments, the screen 68A-1 includes a diffusing coating or film. In some embodiments, a film or coating is applied to the convex front surface 72 to focus the image 64 onto the screen 68A-1.

[0126] 4B, in embodiments in which screen 68A-2 is a front projection screen, projector 80 is positioned to project image 64 onto front surface 72 of screen 68A-2. In some embodiments, projector 80 may be positioned at least partially between front surface 72 of screen 68A-2 and mirror 74.

[0127] The image 64 produced by the projector 80 is reflected from the front surface 72 onto the mirror 74. The screen 68A-2 may be formed of an opaque material. In some embodiments, the screen 68A-2 is formed of glass, plastic, fiberglass, metal, or a similar material.

[0128] Those skilled in the art will appreciate that any arrangement of projector 80, screen 68, and mirror 74 is within the scope of the present disclosure. In some embodiments, variable collimation display system 62 can be used with simulator 40 having screen 68 and mirror 74 of different configurations and arrangements. For example, curved screen 68 can be used with flat mirror 74, curved mirror 74 can be used with flat screen 68, and / or curved mirror 74 can be used with curved screen 68. In one embodiment, screen 68 and mirror 74 are generally concave and curved in more than one dimension.

[0129] 4C, in other embodiments, the variable collimation display system 62 does not include a projector 80. In these embodiments, the screen 68B is a self-luminous screen and may include elements of a projector that projects the image 64 from a front surface 72 of the screen 68B. Thus, the screen 68B projects an image from its front surface 72. The image 64 is then reflected by the front surface 78 of the mirror 74. The screen 68B may be any type of display operable to project an image, such as, for example, a self-luminous curved screen, a set of LED panels, a liquid crystal display, an organic light emitting diode display, a liquid crystal display on silicon, a light emitting diode display, a quantum dot display, or a plasma display.

[0130] Referring to FIG. 4C, the variable collimation display system 62 does not include a projector 80. In these embodiments, the screen 68B is a self-luminous screen and may include elements of a projector that projects an image 64 from a front surface 72 of the screen 68B. Thus, the screen 68B projects an image from its front surface 72. The image 64 is then reflected by a front surface 78 of a mirror 74. The screen 68B may be any type of display operable to project an image, such as, for example, a self-luminous curved screen, a set of LED panels, a liquid crystal display, an organic light-emitting diode display, a liquid crystal display on silicon, a light-emitting diode display, a quantum dot display, or a plasma display. As shown in FIGS. 5A and 5B, during use of the variable collimation display system, an image 64 is projected onto the screen 68 (whether self-projected or projected by a projector 80) and the image is visible to the user 30 as a reflection of the mirror 74. The image 64 is visible to the user 30 as a light beam 66 having a predetermined focus. The light rays 66 are collimated (as shown in FIG. 5A) and appear at a focal length of infinity. Alternatively, by varying the position of the screen 68 relative to the mirror using adjuster 82, the image light rays 66 appear to the user 30 at a fixed focal length. As the screen 68 moves closer to the mirror 74, decreasing the distance 96, the light rays 66 diverge and the focus becomes less than infinity (as shown diagrammatically in FIG. 5B).

[0131] The distance 96 from the screen 68 to the mirror 74 correlates to the focal length of the image 64 as seen by the user 30. As will be explained in more detail, the distance 96 (or focal length) is determined based on a simulated distance 100 from the specified viewpoint 32 to the object 60 depicted in the image 64. The simulated distance is the perceived viewing distance. In other words, the simulated distance may be the distance between the specified viewpoint 32 and the object 60 as perceived by a user at the specified viewpoint if the object were physically present. The simulated distance 100 is also referred to as the "slant distance," "perceived distance," or "line-of-sight distance."

[0132] When the screen 68 is in a first position (shown in FIG. 5A), the mirror 74 is at a first distance 96A from the screen and the focal length is at infinity. Thus, the light rays 66 reflected from the mirror are substantially parallel and the image 64 is collimated. The object 60 in the image 64 is at a first distance 100A from a specified viewpoint and may be displayed at a first simulated size or height 106A.

[0133] 5B, in a second position of the screen 68, the mirror 74 is at a second distance 96B from the screen 68 and the focal length is less than infinity. The second distance 96B is less than the first distance 96A. In the second position, the light beam 66 is slightly diverging, as shown diagrammatically in FIG. 5B.

[0134] Figure 5B also shows a second distance 100B between the specified viewpoint 32 and the object 60 in the image 64, where the second distance 100B is less than the first distance 100A. Thus, in Figure 5B, because the specified viewpoint 32 is closer to the object 60, the object 60 in the image 64 may be displayed at a second simulated size or height 106B. The second height 106B is greater than the first height 106A shown in Figure 5A.

[0135] In some embodiments, if the simulated distance 100 exceeds a predetermined threshold, the screen 68 remains in the first position (i.e., first distance 96A) from the mirror 74. In some embodiments, the predetermined threshold is about 30 feet. In other embodiments, the predetermined threshold may be less than 30 feet or greater than 30 feet.

[0136] The adjuster 82 may move the screen 68 to a second position (i.e., second distance 96B) from the mirror 74 if the simulated distance 100 meets a predetermined threshold. In at least one example, the predetermined threshold correlates to the height above the terrain 102 of the simulated aircraft (e.g., a helicopter, etc.) at which the focal length changes from infinity to less than infinity.

[0137] An example of a simulated scenario in which the predetermined threshold may be met includes a landing simulation. For example, for a simulated aircraft exceeding the predetermined threshold, the focal length of the image 64 seen by the user 30 is at infinity. Thus, the adjuster 82 may move the screen 68 to a first position at a first distance 96A from the mirror 74, as shown generally in FIG. 5A.

[0138] As the simulated aircraft descends toward the landing surface, the altitude 102B decreases and the simulated aircraft reaches a predetermined threshold. As shown generally in FIG. 5B, the adjuster 82 may move the screen 68 from the first position to the second position 96B, decreasing the first distance to the second distance 96B, thereby changing the focal length of the image 64 seen by the user 30 to less than infinity. As the simulated aircraft continues to descend, the adjuster 82 may move the screen 68 to a third position closer to the mirror 74 to continue adjusting the focal length of the image 64.

[0139] During a takeoff simulation, the opposite occurs: for example, during a takeoff simulation, adjuster 82 adjusts distance 96 between first distance 96A and second distance 96B to vary the focal length of image 64 seen by user 30 between infinity and less than infinity, or vice versa.

[0140] 6, the adjuster 82 may be automatically controlled by the controller 120 to move the screen 68 and adjust the distance 96 between the screen 68 and the mirror 74. In another embodiment, the adjuster 82 may be manually controlled by a user or operator via the control system 122.

[0141] 6, the simulator 40 may include a control system 122 in communication with the variable collimation display system 62. Suitable control systems 122 are known to those skilled in the art. In some embodiments, the control system 122 is a personal computer, such as, but not limited to, running the MS Windows operating system, Mac OS, Linux, or other known operating systems. Alternatively, the control system may be a smartphone, tablet computer, laptop computer, and similar computing devices. In other embodiments, the control system is a data processing system including, but not limited to, one or more of input devices (such as a keyboard, mouse, touch screen, etc.), output devices (such as a display, speakers, etc.), graphics cards, communication devices (such as an Ethernet card, wireless communication device, etc.), permanent memory (such as a hard drive), temporary memory (such as a random access memory), computer instructions stored in the permanent and / or temporary memory, and a processor.

[0142] In some embodiments, the control system 122 is integrated or embedded in an image generator associated with the simulator 40. The control system 122 may also be integrated or embedded in a host computer of the simulator. Additionally or alternatively, the control system 122 may be a virtual machine running on (or operated by) the simulator's computer system. In yet other embodiments, the control system 122 is associated with an image generator or a computer system that communicates with the host computer system of the simulator 40.

[0143] Control system 122, according to embodiments of the present disclosure, may include a processor 124, a memory 126, a communication interface 128, and a user interface 130. In some embodiments, control system 122 may have more or fewer components than those shown in Figure 6. Control system 122 may be any suitable computer known to those of skill in the art.

[0144] The processor 124 of the control system 122 may be any processor known to those of skill in the art, including those described herein or similar processors. The processor 124 may execute instructions stored in the memory 126 that may cause the processor 124 to perform one or more computational steps utilizing or based on data received from the variable collimation display system 62.

[0145] The memory 126 may be or include RAM, DRAM, SDRAM, other solid state memory, any memory described herein, or other tangible non-transitory memory that stores computer readable data and / or instructions. The memory 126 may store information or data useful for completing any operation described herein (including the steps or operations of the methods 140 and / or 160 described herein). The memory 126 may store, for example, focal length model 132, size model 134, simulation software, image engine or image generation software, and / or controller instructions 136. Such instructions may be organized into one or more applications, modules, packages, layers, or engines, depending on the embodiment. The instructions cause the processor 124 to operate on data stored in the memory 126 and / or data received from the variable collimation display system 62.

[0146] In some embodiments, the memory 126 includes a lookup table 138. Alternatively, in at least one embodiment, the lookup table 138 includes predefined distances 96 between the mirror 74 and the screen 68 for a number of predefined situations. In some embodiments, the lookup table includes the distance 96 based on a simulated height 102 of the simulated aircraft. Additionally or alternatively, the lookup table may include the distance 96 that the screen is spaced from the mirror based on a tilt range or a simulated distance 100 from a specified viewpoint 32 to an object 60 in the image 64.

[0147] For example, the lookup table 138 may indicate that when the simulated height 102A exceeds a predetermined amount, the regulator 82 should move the screen 68 to a first position at a first distance 96A (as shown diagrammatically in FIG. 5A ). The lookup table 138 includes values ​​that decrease the distance 96 when the simulated height 102 is less than the predetermined amount. For example, if the simulated height 102 is 95% of the predetermined amount, the lookup table may include a second distance 96 expressed as a percentage of the first distance (95% of the first distance). Alternatively, the second distance 96 may be expressed as a distance (in inches or centimeters) that is subtracted from the first distance. Continuing with this example, as the simulated height 102 continues to decrease, the lookup table may include values ​​that decrease the distance 96 between the screen and the mirror until a minimum distance 96 is reached, such as when the simulated aircraft lands.

[0148] In some embodiments, the lookup table 138 may define the distance 96 between the screen 68 and the mirror 74 based on a simulated distance 100 from a specified viewpoint 32 to an object 60 in the image 64. For example, if the simulated distance 100 is greater than a predetermined amount, e.g., 18 feet, the lookup table may indicate that the screen should be at a first distance 96 from the mirror. As the simulated aircraft approaches the object, the lookup table may include values ​​that decrease the distance 96 such that the screen gradually moves closer to the mirror.

[0149] The inclusion of a predetermined value of distance 96 based on one or more of a simulated height 102 and a simulated distance 100 to object 60 can be beneficial to support various flight operations. For example, during a simulated landing or takeoff, it may be beneficial to determine the distance 96 between the screen and the mirror based on the simulated altitude 102 of the aircraft. However, in some simulations, such as a high hover next to an object 60, the simulated height 102 may exceed a predetermined threshold and the screen 68 may be a sufficient distance 96 away from the mirror 74 such that the image 64 of the variable collimation display system is focused at infinity. However, if the simulated aircraft is very close to the object 60, the simulated distance 100 may be less than the predetermined amount. Thus, to decrease the distance 96 and change the focal length of the object 60 in the image 64, the screen may need to be moved toward the mirror.

[0150] The control system 122 may also include a communications interface 128. The communications interface 128 may be used to receive information from an external source (such as the variable collimation display system 62) and / or to transmit commands, data, or other information to an external system or device (e.g., the adjuster 82, the projector 80 (or screen 68B) and / or the variable collimation display system, and the projector 50 of the primary display 48). The communications interface 128 includes one or more wired interfaces (e.g., a USB port, an Ethernet port, a Firewire port) and / or one or more wireless interfaces (e.g., configured to transmit information via one or more wireless communication protocols, such as 802.11a / b / g / n, Bluetooth, NFC, ZigBee, etc.). In some embodiments, the communications interface 128 serves to enable the control system 122 to communicate with one or more other processors 124 or other control systems 122 to reduce the time required to complete a computing-intensive task or for other reasons.

[0151] The control system 122 may also include one or more user interfaces 130. The user interface 130 may be or may include a touchpad (e.g., that of a laptop computer), a keyboard, a mouse, a trackball, a monitor, a television, a touch screen, a joystick, switches, buttons, and / or other devices that receive information from and / or provide information to a user. The user interface 130 may be used, for example, to receive user selections or other user input regarding the focal length model 132, to receive user selections or other user input regarding a simulation performed by the simulator, to receive user input useful in connection with the controller instructions 136, and / or to display the instructions 136. In some embodiments, the user interface 130 may be useful for allowing a user or operator to modify the instructions 136, the adjusters 82 (such as changing the position of the screen 68), or other information that is displayed, although it will be understood that each of the foregoing inputs may be generated automatically by the control system 122 (e.g., by the processor 124 or another component of the control system 122) or may be received by the control system 122 from a source external to the control system 122. In some embodiments, user input as described above may be alternative or not required for the operation of the systems, devices, and methods described herein.

[0152] Although user interface 130 is shown as part of control system 122, in some embodiments, control system 122 may utilize a user interface 130 that is housed separately from one or more remaining components of control system 122. In some embodiments, user interface 130 may be located near one or more other components of control system 122, while in other embodiments, user interface 130 may be located remotely from one or more other components of control system 122.

[0153] 6, the adjuster 82 may include a controller 120. The controller 120 is operable to control the adjuster 82 such that the adjuster 82 moves the screen 68 to change the distance 96 between the screen 68 and the mirror 74. In other embodiments, the adjuster does not include the controller 120.

[0154] Controller 120 may be an electronic, mechanical, or electromechanical controller. Controller 120 may include or be any processor described herein. Controller 120 may include memory that stores instructions to perform any of the functions or methods described herein performed by controller 120. In some embodiments, controller 120 may simply convert signals received from control system 122 (e.g., via communication interface 128) into commands to operate regulator 82. In other embodiments, controller 120 may process and / or convert signals received from regulator 82. Additionally, controller 120 may receive signals from one or more sources (e.g., regulator 82) and output signals to one or more sources.

[0155] 7, a method 140 is provided for adjusting the focal length of an image 64 displayed to a user 30 at a specified viewpoint 32 of a simulator 40. The method 140 may be performed, for example, using the components described above with respect to FIGS.

[0156] The method 140 includes generating an image 64 for display by a screen 68 of a variable collimation display system 62 at operation 142. The image depicts an environment external to the simulated vehicle (e.g., an aircraft) and may include an object 60, such as a tree. The image 64 is transmitted to a projector 80 or screen 68B of the variable collimation display system.

[0157] In some embodiments, projector 80 can project image 64 onto a front surface 72 of screen 68A-2 (if it is a front projection screen) or onto a rear surface 70 of screen 68A-1 (if it is a rear projection screen). In other embodiments, where screen 68B is a self-illuminating screen, the image is projected by screen 68B itself.

[0158] The images may be generated by the control system 122. For example, the images 64 may be generated as part of simulation software stored in the memory 126. In some embodiments, the images 64 are created by image generation software stored in the memory 126.

[0159] In some embodiments, the images 64 are received by the communications interface 128 from another control system, such as a control system that controls the simulator 40 and generates the images.

[0160] The method 140 also includes an operation 144 that includes determining a simulated distance 100 from the specified viewpoint 32 to the object 60 in the image 64. The simulated distance may be a perceived viewing distance. In other words, the simulated distance may be a distance between the specified viewpoint 32 and the object 60 that the user 30 would perceive at the specified viewpoint if the object were physically present. In some embodiments, the simulated distance may be (or may be associated with), for example, a simulated height 102 of the simulated aircraft above the terrain. The height above the terrain 102 may be the distance between the simulated aircraft and the ground surface 26.

[0161] In some embodiments, the simulated distance 100 is determined using the Pythagorean theorem, inputting the simulated aircraft height 102 at the specified viewpoint 32 and the horizontal distance 104 to the object 60. In some embodiments, the simulated distance may be determined using a method 160 described herein.

[0162] The method 140 also includes an operation 146 that includes determining a focal length of the image 64 based on a simulated distance 100 between the specified viewpoint 32 and the object 60 in the image. In some embodiments, determining the focal length of the image includes using a focal length model 132 stored in the memory 126 of the control system 122. In such an embodiment, the processor 124 may input the simulated distance 100 into the focal length model 132, execute the focal length model 132, and receive the focal length as an output from the focal length model 132. In some embodiments, the focal length model 132 may be trained using, for example, historical distances and / or simulated distances obtained from a simulation. Additionally or alternatively, the operation 146 may include retrieving the focal length from a lookup table 138.

[0163] The method 140 may include an optional operation 148 of determining a simulated size 106 of the object 60 to display in the image 64. In some embodiments, the simulator 40 determines the simulated size 106 of the object. More specifically, the simulator 40 may include a control system that executes instructions to determine the simulated size of the object 60. The simulator control system then sends a signal including the simulated size to the communications interface 128. The control system 122 may then send instructions to the projector 80 (or the self-illuminating screen 68B) to project the image 64.

[0164] In some embodiments, the control system 122 inputs the simulated distance 100 into a size model 134 stored in memory 126. The size model then outputs the simulated size 106 to the control system 122 and its processor 124. Alternatively, the size model 134 may be trained using, for example, historical distances and / or simulated distances obtained from a simulation.

[0165] The method 140 may also include generating instructions to the adjuster 82 to change a distance 96 between the screen 68 and the mirror 74 to achieve the focal length in an operation 150. Alternatively, the operation 150 includes retrieving the distance 96 from a lookup table 138 based on one or more of a height 102 above the terrain, a horizontal distance 104 to the object, and a simulated distance 100 to the object in the image.

[0166] In some embodiments, commands are sent to controller 120 to cause adjuster 82 to adjust distance 96. In embodiments in which adjuster 82 includes actuator 92, controller 120 may control the actuator to move screen 68 relative to mirror 74, as described herein.

[0167] The method 140 may also include an operation 152 of adjusting a size 106 of the object 60 in the image 64. The size of the object 60 in the image 64 may be adjusted based on the simulated size determined in operation 148. The size 106 of the object is adjusted to correspond to the adjustment of the distance 96 between the screen 68 and the mirror 74. The size of the object is also adjusted so that the object appears as a physical object at the focal length. In other words, the size 106 of the object is adjusted to match the perceived view of the object if it were physically viewable by the user 30.

[0168] It will be appreciated that the method 140 may include more or less steps than those described above. One or more operations of the method 140 may be looped or repeated as necessary to continually update in real time the focal length of the image 64 displayed to the user 30 and the size 106 of the object 60 as seen in the image. The focal length perceived by the user 30 is adjusted to match the perceived distance 100 to the object 60 displayed in the image 64. As described herein, this is accomplished by changing the distance 96 between the mirror 74 through which the user 30 views the object 60 and the screen 68 on which the image 64 created by the control system 122 is displayed. By manipulating the mirror / screen distance 96, the light beams reflected from the mirror 74 may be adjusted from collimated (parallel light beams), representing an infinite focus or distant object (as shown in FIG. 5A), to gradually diverging light beams, representing a decreasing focal length as the simulated aircraft approaches the object and / or the ground (as shown in FIG. 5B). By adjusting the focal length of the image in real time, the user's view of the environment becomes more accurate, especially during takeoff and / or landing procedures.

[0169] With reference to FIG. 8, a method 160 of determining simulated distance 100 is provided. Method 160 may be performed, for example, using the systems and components described above with respect to FIGs. 2-7. In some embodiments, method 160 is performed before method 140. Additionally or alternatively, method 160 may be performed during method 140. For example, method 160 may be performed before operation 146. Method 140 may be paused until method 160 is performed, and then method 140 is resumed upon completion of method 160.

[0170] An alternative operation 162 of method 160 includes receiving a location of the designated viewpoint 32. In some embodiments, the location of the designated viewpoint 32 may be received as input from a user via user interface 130. In other embodiments, the location of the designated viewpoint 32 may be determined by a sensor located near or at the designated viewpoint 32. For example, the user may wear a headset with a sensor that transmits sensor data including the location of the sensor to the control system 122. Additionally or alternatively, the location of the designated viewpoint 32 may be retrieved from memory 126 of the control system 122.

[0171] The method 160 also includes, in operation 164, determining a simulated position of the object 60 depicted in the image 64 relative to the specified viewpoint 32. In some embodiments, determining the simulated position of the object may include determining a distance between the position of the specified viewpoint 32 and the mirror 74. Additionally or alternatively, the position of the object (or simulated distance 100 to the object) may be received from the simulator 40, or as an output of simulation software, or from an image generator that creates the images for the simulator.

[0172] The method 160 may also include an operation 166 of determining a distance between the position of the specified viewpoint 32 and the simulated position of the object 60 to obtain a simulated distance 100. The simulated position of the object is received from operation 164. In some embodiments, determining the distance includes subtracting the x- and / or y-coordinates of the specified viewpoint 32 from the x- and / or y-coordinates of the simulated position of the object 60.

[0173] It will be appreciated that the method 160 may include more or fewer steps than those described above.

[0174] Methods and systems described herein use mirrors, screens, adjusters, and control systems to adjust the focal length of an image displayed to a user at a specified viewpoint of the simulator, and adjust the focal length in real time. These methods and systems advantageously adjust the focal length of the image as the simulator simulates moving closer to or farther from the image from the specified viewpoint. Such focal length adjustments increase the realism of the image to the user, enhancing the simulation experience, particularly during simulated landing or takeoff.

[0175] Another advantage of the methods and systems described herein is that the object 60 displayed in the image 64 of the variable collimation display system 62 is aligned (and of corresponding size) with the object 60 displayed in the image 56 generated by the primary display 48. This increases the realism of the simulations performed in the simulator.

[0176] The variable collimation display system 62 of the disclosed embodiments provides the additional advantage of being compatible with night vision goggles (NVGs) in the situations in which NVGs are focused in a real aircraft. More specifically, as one skilled in the art will appreciate, the NVGs used in the simulator 40 are focused at or near infinity to match the focus of the primary "out-of-window" display 48, as would be the case in the real aircraft that the simulator 40 replicates. This level of realism is important because it means that the instrument panel in the simulator cockpit 42 is not in focus with the NVGs, as would be the case in a real aircraft. In order to see the instrument panel in the simulator, the pilot 30 must "train to fly" and learn to glance below the night vision goggles to pick up instrument cues.

[0177] The variable collimation display system 62 associated with the lower window 46 of the simulator 40 of the present disclosure can generate a near-infinity focus in some simulated flight situations (e.g., high altitude hovering). Thus, when the screen 68 of the variable collimation display system is in a first position at a first distance 96A (shown in FIG. 5A ) from the mirror 74 to generate a near-infinity focus, the image 64 generated by the variable collimation display system 62 is compatible with (or in focus when viewed through) the NVG. This is similar to a pilot viewing an object through the lower window of a real aircraft (or helicopter) during high altitude hovering.

[0178] When a real aircraft descends from a high-altitude hover, objects get closer and are no longer in focus in the NVGs, so the pilot must glance below the NVGs to see the objects through the lower window as the aircraft descends.

[0179] The variable collimation display system 62 can replicate this by moving the screen 68 to a second position at a second distance 96B (see FIG. 5B) from the mirror 74. In this second position, the image 64 is less than infinity focused. The pilot user 30 must then look under the night vision goggles and pick up ground cues through the simulator's lower window 46 (as in a real aircraft). In this manner, the variable collimation display system 62 of the present disclosure builds positive habits and enhances the realism of the simulator 40.

[0180] As will be appreciated based on the above disclosure, the present disclosure encompasses methods including fewer than all of the steps identified in Figures 7 and 8 (and the corresponding description of methods 140 and 160), as well as methods including additional steps beyond those identified in Figures 7 and 8 (and the corresponding description of methods 140 and 160). Although the general order of methods 140 and 160 is shown in Figures 7-8, one of ordinary skill in the art will appreciate that the steps of the methods may be arranged and performed differently than that shown in Figures 7-8. Additionally, although the steps of the methods may be described in a sequential order, many of the steps may in fact be performed in parallel or simultaneously.

[0181] Although various embodiments of the system have been described in detail, it is clear that modifications and alterations of those embodiments will occur to those skilled in the art. Such modifications and alterations are expressly understood to be within the scope and spirit of the present disclosure. It is further understood that the phraseology and terminology used herein are for descriptive purposes and should not be considered as limiting. As used herein, "including," "comprising," or "having" and variations thereof are intended to encompass the items listed thereafter and equivalents thereof, as well as additional items.

[0182] Several variations and modifications of the disclosure may be used, and it is possible to provide some of the features of the disclosure and not provide other features.

[0183] The features of the various embodiments described herein are not intended to be mutually exclusive. Instead, features and aspects of one embodiment can be combined with features or aspects of another embodiment. Furthermore, a description of a particular element with respect to one embodiment may apply to the use of that particular element in other embodiments, regardless of whether the description is repeated in connection with the use of the particular element in other embodiments.

[0184] Furthermore, although the description of the present disclosure includes a description of one or more embodiments, configurations, or aspects, as well as specific variations and modifications, other variations, combinations, and modifications are within the scope of the present disclosure, e.g., as may be within the skill and knowledge of one of ordinary skill in the art after understanding the present disclosure. This is intended to acquire rights to include alternative embodiments, configurations, or aspects to the extent permitted, including alternative, interchangeable, and / or equivalent structures, functions, scopes, or steps, and is not intended to provide the public with patentable subject matter, whether or not such alternative, interchangeable, and / or equivalent structures, functions, scopes, or steps are disclosed herein.

[0185] One aspect of the present disclosure includes any one or more of the aspects / embodiments substantially as disclosed herein.

[0186] Another aspect of the present disclosure is any one or more of the aspects / embodiments substantially as disclosed herein, optionally in combination with any one or more of the other aspects / embodiments substantially as disclosed herein.

[0187] Another aspect of the present disclosure is to provide one or more means adapted to carry out any one or more of the above-mentioned aspects / embodiments substantially as disclosed herein.

[0188] Aspects of the present disclosure may take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects (all of which are generally referred to herein as "circuits," "modules," or "systems"). Any combination of one or more computer readable media may be used. The computer readable medium may be a computer readable signal medium or a computer readable storage medium.

[0189] A computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (non-exhaustive list) of computer-readable storage media include an electrical connection with one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0190] A computer-readable signal medium may include a propagated data signal in which computer-readable program code is embodied, for example in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including but not limited to electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium is not a computer-readable storage medium, but is any computer-readable medium that can communicate, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied in a computer-readable medium may be transmitted using any suitable method, including but not limited to wireless, wired, fiber optic cable, RF, etc., or any suitable combination of the foregoing.

[0191] As used herein, the terms "determining," "calculating," and "computing," and variations thereof, are used interchangeably and include any type of methodology, process, mathematical operation, or technique.

[0192] Examples of processors described herein include the Qualcomm® Snapdragon® 800 and 801, Qualcomm® Snapdragon® 610 and 615 with 4G LTE integration and 64-bit computing, Apple® A7 processor with 64-bit architecture, Apple® M7 motion coprocessor, Samsung® Exynos® series, Intel® Core™ processor family, Intel® Xeon® processor family, Intel® Atom™ processor family, Intel Itanium™ processor family, Intel® Core™ i5-4670K and i7-4770K 22nm Haswell, Intel® Core™ i5-3570K 22nm Ivy Bridge, AMD® FX™ processor family, AMD® FX-4300, FX-6300, and FX-8350 32nm Vishera, AMD® Computational functions may be performed using Kaveri processors, Texas Instruments® Jacinto C6000™ automotive infotainment processors, Texas Instruments® OMAP™ automotive-grade mobile processors, ARM® Cortex™-M processors, ARM® Cortex-A and ARM926EJ-S™ processors, other industry equivalent processors, and any known or future developed standards, instruction sets, libraries, and / or architectures.

[0193] To provide additional background, context, and to further satisfy the written description requirements of 35 U.S.C. § 112, the following references are hereby incorporated by reference in their entireties: U.S. Pat. No. 9,191,659; U.S. Pat. No. 10,942,360; and Canadian Patent Publication No. 3,113,582. [Explanation of symbols]

[0194] Below is a list of components shown in the drawings, according to various embodiments of the present disclosure: Number Component 2. Conventional simulator 4 Primary Display 6. Projector 8 Screens 10 Mirror Array 12 Primary display image 14 Parallel rays 16 Objects in the image 18 Lower Window 20 Real Image Display System 22 Monitor or screen of real image display system 24 Real image display system images 26 Simulated Ground 28 Simulated height above ground 30 users 32 Specified viewpoint 34 First arrow showing the direction of gaze on the primary display 36 Second arrow showing the direction of sight through the lower window 40 Simulator 42 Cockpit 44 Primary Display Window 45 Top Window 46 Lower Window 48 Primary Display 50 Primary display projector 52 screens 54 Mirror Array 56 Primary Display Image 58 Parallel rays 60 Image Objects 62 Variable collimation display system (or downward display, or variable display) 64 Variable collimation display system image 66 Variable collimation display system light beam 68 Screen of variable collimation display system 68A-1 Rear or back projection screen 68A-2 Front Projection Screen 68B Self-luminous screen 70 Back of Screen 68 72 Front of Screen 68 74 Variable collimation display system mirror 76 Back of mirror 74 78 Front of mirror 74 80 Variable collimation display system projector 82 Adjuster for variable collimation display system 84 Platform 86 Platform movement arrow 88 Screen Stand 90 Projector Mount 92 Actuator 94 Stops 96 Distance between mirror and screen 96A First Distance 96B Second Distance 98 Projector to screen distance 100 Perceived Distance The (or simulated) distance between a given viewpoint and a simulated object 102 Height above terrain 104 Horizontal distance to object 106 Simulated size or height of object 120 Controller 122 Control System 124 processors 126 Memory 128 Communication Interface 130 User Interface 132 focal length model 134 size model 136 Controller Instructions 138 Lookup Table 140 method Generate 142 images 142 Determine the simulated distance to an object 146 Determine the focal length 148 Determine the simulated size of an object 150 Generate adjustment instructions 152 Adjust the simulated size of an object 160 method 162 Receive the specified viewpoint position 164 Determine the simulated position of an object 166 Determine the simulated distance

Claims

1. 1. A system for adjusting a focal length of an image displayed to a user at a specified viewpoint, comprising: a screen for displaying an image depicting an object; a mirror spaced a variable distance from said screen for reflecting an image displayed by said screen to a designated viewpoint; an adjuster for moving the screen and adjusting the distance between the screen and the mirror; A system including:

2. a control system in communication with the regulator; The control system includes: determining a focal length of the image based on a simulated distance between the specified viewpoint and the object in the image; determining a simulated size of the object based on the simulated distance; generating commands to the adjuster to adjust the distance between the screen and the mirror to achieve the focal length; adjusting a size of the object in the image based on the determined simulated size; The system of claim 1 ,

3. The control system further generates the image. The system of claim 2.

4. the screen is at least one of a liquid crystal display, an organic light emitting diode display, a liquid crystal on silicon display, a light emitting diode display, a quantum dot display, and a plasma display; The system of claim 1 .

5. a projector for projecting the image onto the screen; the screen being one of a front projection screen and a rear projection screen; The system of claim 1 .

6. the projector is at a fixed distance from the screen; The adjuster moves the screen and the projector. The system of claim 5.

7. the adjuster includes a motor that moves the screen and adjusts the distance; The system of claim 1 .

8. the mirror is fixed and the screen is interconnected to the modulator platform; the platform moves to adjust the distance between the screen and the mirror; The system of claim 7.

9. The adjuster includes a stopper that prevents the screen from contacting the mirror. The system of claim 8.

10. the distance between the screen and the mirror is a function of the focal length; In a first position, the screen is at a first distance from the mirror and the focal length is at infinity; in a second position, the screen is a second distance from the mirror and the focal length is less than infinity; The first distance is greater than the second distance. The system of claim 1 .

11. In the first position, the light beams reflected from the mirror are substantially parallel. The system of claim 10.

12. Associated with a simulator that simulates an aircraft, the simulator includes a lower window disposed between the designated viewpoint and the mirror; an image displayed by said screen is visible to a user through said lower window; A system according to any one of claims 1 to 11.

13. 1. A control system for a simulator that adjusts a focal length of an image at a specified viewpoint of the simulator, comprising: A processor; a memory for storing instructions to be executed by the processor; When the instructions are executed, the processor: generating an image that is reflected by a mirror and displayed by a screen that is oriented to pass through a lower window of the simulator toward a designated viewpoint; determining a simulated distance from the specified viewpoint to an object in the image; determining a focal length of the image based on the simulated distance; determining a simulated size of the object based on the simulated distance; generating commands to an adjuster to vary the distance between said screen and said mirror to achieve said focal length; adjusting a size of the object in the image based on the determined simulated size; A control system that executes the above.

14. Determining the simulated distance comprises: receiving the specified viewpoint position; determining a simulated position of the object relative to the specified viewpoint; determining a distance between the specified viewpoint position and a simulated position of the object; The control system of claim 13 , comprising one or more of the following:

15. the distance between the screen and the mirror is a function of the focal length; The memory further comprises: instructions to the processor to move the screen to a first position that is a first distance from the mirror such that the focal length is at infinity when the simulated distance exceeds a predetermined threshold; 14. The control system of claim 13.

16. The memory further comprises: instructions to the processor to move the screen to a second position, the focal length being less than infinity and a second distance from the mirror, when the simulated distance is less than a predetermined threshold; The first distance is greater than the second distance.

16. The control system of claim 15.

17. The predetermined threshold is approximately 30 feet.

16. The control system of claim 15.

18. 1. A method for adjusting a focal length of an image at a specified viewpoint, comprising: The method comprises: generating an image for display on a screen oriented such that the image is reflected by a mirror to a specified viewpoint; determining a simulated distance between the specified viewpoint and a simulated position of an object in the image; determining a focal length of the image based on the simulated distance; determining a simulated size of the object based on the simulated distance; generating commands to an adjuster to change the distance between said screen and said mirror to achieve said focal length; adjusting a size of the object in the image based on the simulated size; The method includes:

19. when the simulated distance exceeds a predetermined threshold, moving the screen to a first position at a first distance from the mirror such that the focal length is at infinity; when the simulated distance is less than a predetermined threshold, moving the screen towards the mirror to a second position that is a second distance from the mirror such that the focal length is less than infinity; The first distance is greater than the second distance.

20. The method of claim 18.

20. 1. A flight simulator for training students to pilot aircraft, comprising: a primary display system simulating a view out of a window of the aircraft; a variable collimation display system simulating a second view outside the aircraft as seen through a lower window located within the simulator cabin near a floor of the cabin; The primary display system comprises: a projector, a first screen, and a mirror array; the projector is operable to generate a first image to be displayed on the first screen; the mirror array reflects the first image to a designated viewpoint of the simulator; The variable collimation display system a second screen for displaying a second image; a mirror that reflects the second image from the second screen through the lower window to a designated viewpoint; an adjuster for moving the second screen relative to the mirror; when the second screen is at a first distance from the mirror, the second image is at an infinity focus; when the second screen is at a second distance from the mirror, the second image has a fixed focal length that is less than infinity; the second distance is less than the first distance; Flight simulator.

21. the mirror is at a fixed distance from a designated viewpoint; 21. A flight simulator according to claim 20.

Images