Patent Description:
As HUD imagery often involves symbols and/or images that are overlaid of what the pilot sees through the cockpit window, it is important that the combiner accurately projects the imagery onto the cockpit window so that the HUD imagery and the real-world view are aligned properly. A proper alignment of the combiner may be determined through a combiner alignment detector (CAD). Current CADs utilize infrared or near infrared emitters coupled with detectors that are suffer from low sensitivity, low directionality awareness, and pollute night vision imaging systems. Accordingly, it is desirable to provide combiner alignment solution that is more sensitive and provides better directionality awareness than conventional approaches without polluting night vision imagine systems. <CIT> relates to dual mode imaging. <CIT> relates to a combiner alignment detector for a head up display system.

A system for detecting an alignment of a relay lens assembly and a combiner of a head-up display is disclosed. The system includes an illuminated reticle spatially coupled to the relay lens assembly, wherein a movement of the relay lens assembly results in a commensurate movement of the illuminated reticle. The system further includes an optical sensor spatially coupled to the combiner or optically coupled to a mirror spatially coupled to the combiner. The optical sensor is configured to detect a light pattern emitted from the illuminated reticle. The system includes a control module comprising one or more processors and a memory. The control module is configured to receive an input from the optical sensor. In some embodiments, the control module is configured to determine a position of the combiner relative to the relay lens assembly based on the received input. The control module is configured to generate an output based on a determined position of the combiner relative to the relay lens assembly.

In some embodiments of the system, the illuminated reticle is configured to emit light at a wavelength equal or less than <NUM>.

In some embodiments of the system, the illuminated reticle is configured to emit light at a wavelength ranging from <NUM> to <NUM>.

In some embodiments of the system, the system further comprises the mirror coupled to the combiner, wherein the mirror is configured to reflect light from the illuminated reticle to the optical sensor.

The control module is configured to determine the distance between the controller and the relay lens assembly.

The illuminated reticle comprises a light emitting diode and a diffuser.

Another system for detecting an alignment of a relay lens assembly and a combiner of a head-up display is also disclosed. The system includes an illuminated reticle spatially coupled to the combiner, wherein a movement of the combiner results in a commensurate movement of the illuminated reticle. The system further includes an optical sensor spatially coupled to the relay lens assembly combiner or optically coupled to a mirror spatially coupled to the relay lens assembly. The optical sensor is configured to detect a light pattern emitted from the illuminated reticle. The system includes a control module communicatively coupled to the optical sensor comprising one or more processors and a memory. The control sensor is configured to receive an input from the optical sensor. The control sensor is configured to determine a position of the combiner relative to the relay lens assembly based on the received input. The control sensor is configured to generate an output based on a determined position of the combiner relative to the relay lens assembly.

In some embodiments of the system, the system further includes the mirror coupled to the combiner, wherein the mirror is configured to reflect light from the illuminated reticle to the optical sensor.

In some embodiments of the system, the optical sensor is configured as a camera.

In some embodiments of the system, the system is configured to participate in a feedback loop with the head-up display, wherein the control module is further configured to receive position data of at least one of the relay lens assembly, the combiner, or an emission of a flight information signal, wherein the feedback loop is configured to reduce jitter in the head-up display.

A system for detecting an alignment of a relay lens assembly and a combiner is disclosed. Specifically, a system for detecting the alignment of a relay lens assembly of an overhead unit of a head-up display is disclosed. The system includes an illuminated reticle that is fixed to a position relative to either the relay lens assembly or the combiner, and a sensor (e.g., camera) that can detect the reticle. The sensor is fixed to a position relative to the relay lens assembly or the combiner that is opposite of that of the illuminated reticle (e.g., the illuminated reticle and the sensor are fixed to different components). The sensor is communicatively coupled to a control module configured to determine whether the combiner is configured within the correct orientation relative to the relay lens assembly.

<FIG> illustrates a combiner alignment detection (CAD) system <NUM> configured to detect the status of an optical alignment between a combiner <NUM> and a relay lens assembly <NUM> of a head up display (HUD), in accordance with one or more embodiments of this disclosure. The HUD includes the combiner <NUM> and the relay lens assembly <NUM>. When in use, the relay lens assembly <NUM> transmits flight information <NUM> (e.g., a flight information signal in the form of images, text, icons) to the combiner <NUM>, where the combiner <NUM> mixes (e.g., combines) the information with a real-world view, such as a view from a cockpit window <NUM>. The HUD enables a pilot <NUM> to efficiently receive the flight information <NUM> needed for operating the aircraft. The CAD system <NUM> may be configured as a stand-alone system apart of the HUD, or may have one or more components combined with the HUD.

In some embodiments, the components of the HUD, including the relay lens assembly <NUM> are firmly installed and aligned to the aircraft using attachment bushings or hardpoints aligning to the aircraft boresight. Because of this, the relay lens assembly <NUM>, as well as other components of the HUD, may be regarded as spatially coupled to the aircraft. That is, when the aircraft moves or suddenly shifts, the relay lens assembly <NUM> retains the same relative position within the aircraft. In contrast, the combiner <NUM> is often installed in a configuration that allows the combiner <NUM> to be moved from the view of the pilot <NUM> during specific aircraft tasks, emergencies, or accidents (e.g., to prevent head injuries). Therefore, the combiner, not being as rigidly attached to the hardpoints on the aircraft, moves considerably in relation to the aircraft as compared to the relay lens assembly, necessitating the need for the CAD system <NUM>.

In some embodiments, the CAD system <NUM> includes a sensor <NUM> and a reticle <NUM> (e.g., an illuminated reticle), wherein the sensor <NUM> is configured to detect a reticle signal <NUM> emitted from the reticle <NUM>. For example, the reticle <NUM> may be configured to emit electromagnetic radiation. For instance, the reticle may be configured to emit light, such as light that does not interfere with a night vision imaging system (NVIS). The sensor <NUM> correspondingly may be configured to detect any electromagnetic energy emitted from the reticle <NUM> including light, such as light that does not interfere with NVIS. The electromagnetic energy emitted of the reticle <NUM> may be controlled by any electrical system external or internal to the CAD system <NUM>. For example, the CAD system <NUM> may supply the power for the reticle <NUM> and/or control the intensity of the electromagnetic energy emitted from the reticle <NUM>. In another example, the power and/or control of the electromagnetic energy of the reticle <NUM> may be supplied by a circuit isolated from the CAD system <NUM>, such as the generally lighting circuitry of the vehicle.

For reticles <NUM> configured to emit visible light or near-visible light (e.g., infrared light or ultraviolet light), the light source associated with the reticle <NUM> may include any type of light source including but not limited to light-emitting diodes (LEDs), incandescent bulbs, fluorescent lamps (e.g., compact fluorescent lamps), halogen lamps, or lasers. For example, the light source associated with the reticle <NUM> may be configured as a blue LED. The reticle <NUM> further includes a diffuser configured to diffuse light. For example, the reticle may be configured as an LED optically coupled to a diffuser.

The reticle <NUM> may be configured to emit light of any one or more wavelengths. The reticle <NUM> may also be configured to emit light (e.g., an illuminating reticle <NUM>) of any one or more or ranges of wave lengths including but not limited to light within a range of <NUM> to <NUM>, within a range of <NUM> to <NUM>, within a range of <NUM> to <NUM>, within a range of <NUM> to <NUM>, and within a range from <NUM> to <NUM>. For example, the reticle <NUM> may be configured to emit a light of approximately <NUM>. As mentioned above, the use of short wavelength (e.g., blue or near UV) light decreases the interference with NVIS systems. For example, the reticle may be configured to ensure compliance with MIL-STD-<NUM> for both NVIS Class B and Class C requirements. Associated document <NPL> has been incorporated by reference in its entirety. For instance, FIG. C-<NUM> (pg. <NUM>) of document MIL-STD-<NUM>. pdf provides spectral transmission requirements for a Class C NVIS objective lens by which the reticle <NUM> used within the Class C NVIS system would be required to emit at a compatible wavelength or set of wavelengths. In another instance, <NPL> provide chromaticity and radiance requirements for Class B NVIS systems by which the reticle <NUM> used within the Class C NVIS system would be required to emit at a compatible wavelength and/or radiance.

The reticle <NUM> may emit any pattern or shape of electromagnetic energy. For example, the reticle <NUM> may be configured to emit a light pattern that includes one or more dots. For instance, the light pattern for the reticle <NUM> may be configured as a set of dots having different sizes and arranged in a symmetrical pattern. The light pattern is configured so that, once detected by the sensor <NUM>, the CAD system <NUM> may recognize the light pattern and determine the X,Z position of the reticle <NUM> relative to the position of the sensor <NUM>. The CAM system <NUM> is configured to determine the distance from the sensor <NUM> to the reticle <NUM> based on the dispersion of the light from the reticle <NUM>, as the dispersion of light from the reticle <NUM> increases as the distance between the reticle and the sensor <NUM> increases.

The sensor <NUM> may be configured as any device configured to detect electromagnetic energy from the reticle <NUM>. For example, the sensor <NUM> may be configured as an optical sensor configured with one or more photo-sensitive devices including but not limited to photoresistors, phototransistors, and photodiodes. For instance, the sensor <NUM> may be configured as a camera. In particular, the sensor <NUM> may be configured as a digital camera capable of converting a captured image into an electric signal.

In some embodiments, the reticle <NUM> is coupled directly or indirectly to the relay lens assembly <NUM>, with the sensor <NUM> coupled directly or indirectly to the combiner <NUM>. For example, the reticle <NUM> may be directly attached to a housing that houses the relay lens assembly <NUM>, and the sensor <NUM> may be directly attached to the combiner. The sensor <NUM> detects light emitted from the reticle <NUM>, resulting in an electrical signal that is sent from the sensor <NUM> for processing. Therefore, in this configuration of the CAD system <NUM>, the reticle <NUM> is spatially coupled to the relay lens assembly <NUM> (e.g., a movement of the relay lens assembly results in a commensurate movement of the illuminated reticle), and the sensor <NUM> is spatially coupled to the combiner <NUM>, allowing the CAD system <NUM> to accurately determine the position of the combiner <NUM> relative to the relay lens assembly <NUM> based on the input received from the sensor <NUM>.

The reticle <NUM> and the sensor <NUM> may be arranged at any distance from each other or at any range of distance from each. For example, the reticle <NUM> and the sensor <NUM> may be positioned <NUM> to <NUM> from each other. In another example, the reticle <NUM> and the sensor <NUM> may be positioned <NUM> to <NUM> from each other. In another example, the reticle <NUM> and the sensor <NUM> may be positioned <NUM> to <NUM> from each other. For instance, the reticle <NUM> and the sensor <NUM> may be positioned approximately <NUM> from each other. In another example, the reticle <NUM> and the sensor <NUM> may be positioned <NUM> to <NUM> from each other.

<FIG> illustrates a CAD system <NUM> configured to detect the status of an optical alignment between the combiner <NUM> and the relay lens assembly <NUM> of a HUD, in accordance with one or more embodiments of this disclosure. The CAD system <NUM> includes one or more, or all the components of the CAD system <NUM>, and vice-versa. In some embodiments, the CAD system <NUM> includes a mirror <NUM> coupled to combiner <NUM> and configured to reflect the reticle signal <NUM> from the reticle <NUM> to the sensor <NUM>. (e.g., the mirror <NUM> is optically coupled to the sensor <NUM>). For example, the reticle <NUM> may be directly or indirectly coupled to the relay lens assembly <NUM>, the sensor <NUM> may be directly or indirectly coupled to the relay lens assembly <NUM>, and the mirror reflects light emitted from the reticle <NUM> to the sensor <NUM>, resulting in an electrical signal that is sent from the sensor <NUM> for processing. Therefore, in this configuration of the CAD system <NUM>, the reticle <NUM> is spatially coupled to the relay lens assembly <NUM>, the mirror is spatially coupled to the combiner <NUM>, and the sensor <NUM> is spatially coupled to the relay lens assembly <NUM> as well as optically coupled to the mirror <NUM>), allowing the CAD system <NUM> to accurately determine the position of the combiner <NUM> relative to the relay lens assembly <NUM> based on the input received from the sensor <NUM>.

<FIG> illustrates a CAD system <NUM> configured to detect the status of an optical alignment between the combiner <NUM> and the relay lens assembly <NUM> of a HUD, in accordance with one or more embodiments of this disclosure. The CAD system <NUM> includes one or more, or all the components of the CAD system <NUM>, <NUM>, and vice-versa. In some embodiments, the CAD system <NUM> includes one or more bushings 304a-c attached to the aircraft frame <NUM> that are configured to firmly couple, directly or indirectly, the HUD, components of the HUD (e.g., bushings <NUM> a,b for the relay lens assembly <NUM>), and the sensor <NUM> (e.g., bushings 304c) to the aircraft frame <NUM>. The attachment of the bushings 304a-c directly or indirectly to the relay lens assembly <NUM> and the sensor <NUM> ensure that the relay lens assembly <NUM> and the sensor <NUM> are spatially coupled to each other, even if the relay lens assembly <NUM> and the sensor <NUM> are not immediately adjacent to each other. In the CAD system <NUM>, the reticle <NUM> is coupled to the combiner <NUM>, and is configured to emit the reticle signal <NUM> a relatively short distance to the sensor <NUM>. Therefore, in this configuration of the CAD system <NUM>, the sensor <NUM> is spatially coupled to the relay lens assembly <NUM>, and the reticle <NUM> is spatially coupled to the combiner <NUM>, allowing the CAD system <NUM> to accurately determine the position of the combiner <NUM> relative to the relay lens assembly <NUM> based on the input received from the sensor <NUM>.

<FIG> illustrates a CAD system <NUM> configured to detect the status of an optical alignment between the combiner <NUM> and the relay lens assembly <NUM> of a HUD, in accordance with one or more embodiments of this disclosure. The CAD system <NUM> includes one or more, or all of the components of the CAD system <NUM>, <NUM>, <NUM>, and vice-versa. In some embodiments, the sensor <NUM> of the CAD system <NUM> is directly or indirectly attached, positioned adjacent to, and spatially coupled to, the relay lens assembly. For example, the relay lens assembly <NUM> may be attached directly or indirectly to the aircraft frame <NUM> (e.g., via bushings 304a,b) while the sensor <NUM> is coupled directly or indirectly to the relay lens assembly <NUM> (e.g., the sensor <NUM> relies on the same bushings <NUM> a,b for coupling to the aircraft frame <NUM>, which also assist in spatially coupling the relay lens assembly <NUM> to the sensor <NUM>. The reticle <NUM> of the CAD system <NUM> is spatially coupled to the combiner <NUM> (e.g., a movement of the combiner results in a commensurate movement of the illuminated reticle), and configured to emit a reticle signal <NUM> to the sensor <NUM>. Therefore, in this configuration of the CAD system <NUM>, the sensor is <NUM> spatially coupled to the relay assembly <NUM>, and the reticle <NUM> is spatially coupled to the combiner <NUM>, allowing the CAD system <NUM> to accurately determine the position of the combiner <NUM> relative to the relay lens assembly <NUM> based on the input received from the sensor <NUM>.

<FIG> illustrates a CAD system <NUM> configured to detect the status of an optical alignment between the combiner <NUM> and the relay lens assembly of a HUD, in accordance with one or more embodiments of this disclosure. The CAD system <NUM> includes one or more, or all of the components of the CAD system <NUM>, <NUM>, <NUM>, <NUM>, and vice-versa. In some embodiments, the CAD system <NUM> includes the mirror <NUM>, which is directly or indirectly coupled to the relay lens assembly <NUM> or the aircraft frame <NUM>, the sensor <NUM> and the relay lens assembly <NUM> is directly or indirectly coupled to the aircraft frame <NUM>. The reticle <NUM> is spatially coupled to the combiner <NUM>, and is configured to emit the reticle signal <NUM> toward the mirror <NUM>, which is then reflected to the sensor. Therefore, in this configuration of the CAD system <NUM>, the sensor <NUM> is spatially coupled to the relay assembly <NUM>, and the reticle <NUM> is spatially coupled to the combiner <NUM>, allowing the CAD system <NUM> to accurately determine the position of the combiner <NUM> relative to the relay lens assembly <NUM> based on the input received from the sensor <NUM>.

It should be understood that the CAD systems <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may include any number or arrangement of components that are associated with the emission of the reticle signal <NUM> by the reticle <NUM> and the reception of the reticle signal <NUM> by the sensor <NUM> provided that the position of the combiner <NUM> can be determined relative to the relay lens assembly <NUM>. Therefore, the above description should not be interpreted as a limitation of the present disclosure, but merely an illustration.

<FIG> is a block diagram of a CAD system <NUM> communicatively coupled to an HUD control module <NUM>, in accordance with one or more embodiments of the disclosure. The HUD control module <NUM> is configured as one of the one or more processing units for the HUD <NUM>, which also includes the combiner <NUM> and an overhead unit <NUM> containing the relay lens assembly <NUM>. The CAD system <NUM> may be configured as a stand-alone system apart from the HUD <NUM> or may have one or more components combined with the HUD <NUM>.

The CAD system <NUM> includes one or more, or all of the components of the CAD system <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and vice-versa (e.g., CAD system <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may have one or more, or all of the components of the CAD system <NUM>). The CAD system <NUM> includes a control module <NUM> configured to receive input from the sensor <NUM>, determine a position based on the combiner <NUM> relative to the relay lens assembly <NUM> based on the received input, and generate an output based on a determined position of the a, b combiner <NUM> relative to the relay lens assembly <NUM>. Once generated, the output is transmitted to the HUD control module <NUM>. The HUD control module <NUM> may then determine whether the signal emitted from the relay lens assembly <NUM> should be adjusted based on the output, whether the position of the combiner should be adjusted based on the output, or both.

In some embodiments, the control module <NUM> includes a controller <NUM> that includes one or more processors <NUM>, a memory <NUM>, and a communication interface <NUM>. The controller <NUM> is configured to provide processing functionality for at least the control module <NUM> and includes the one or more processors <NUM> (e.g., microcontrollers, circuitry, field programmable gate array (FPGA), central processing units (CPU), application-specific integrated circuit (ASIC), or other processing systems), and resident or external memory <NUM> for storing data, executable code, and other information. The controller <NUM> can execute one or more software programs embodied in a non-transitory computer readable medium (e.g., memory <NUM>) that implement techniques described herein. The controller <NUM> is not limited by the materials from which it is formed or the processing mechanisms employed therein and, as such, can be implemented via semiconductor(s) and/or transistors (e.g., using electronic integrated circuit (IC) components), and so forth.

The memory <NUM> can be an example of tangible, computer-readable storage medium that provides storage functionality to store various data and/or program code associated with operation of the controller <NUM>, such as software programs and/or code segments, or other data to instruct the controller <NUM>, and possibly other components of the control module <NUM>, to perform the functionality described herein. Thus, the memory <NUM> can store data, such as a program of instructions for operating the control module <NUM>, including its components (e.g., controller <NUM>, communication interface <NUM>, etc.), and so forth. The memory <NUM> may also store data derived from the sensor <NUM>. It should be noted that while a single memory <NUM> is described, a wide variety of types and combinations of memory <NUM> (e.g., tangible, non-transitory memory) can be employed. The memory <NUM> may be integral with the controller <NUM>, may comprise stand-alone memory, or may be a combination of both. Some examples of the memory <NUM> may include removable and non-removable memory components, such as random-access memory (RAM), read-only memory (ROM), flash memory (e.g., a secure digital (SD) memory card, a mini-SD memory card, and/or a micro-SD memory card), solid-state drive (SSD) memory, magnetic memory, optical memory, universal serial bus (USB) memory devices, hard disk memory, external memory, and so forth.

The communication interface <NUM> may be operatively configured to communicate with components of the control module <NUM> and the system <NUM>. For example, the communication interface <NUM> can be configured to retrieve data from the controller <NUM> or other components, transmit data for storage in the memory <NUM>, retrieve data from storage in the memory <NUM>, and so forth. The communication interface <NUM> can also be communicatively coupled with the controller <NUM> to facilitate data transfer between components of the control module <NUM> and the controller <NUM>. It should be noted that while the communication interface <NUM> is described as a component of the control module <NUM>, one or more components of the communication interface <NUM> can be implemented as external components communicatively coupled to the control module <NUM> via a wired and/or wireless connection. The control module <NUM> can also include and/or connect to one or more input/output (I/O) devices. In embodiments, the communication interface <NUM> includes or is coupled to a transmitter, receiver, transceiver, physical connection interface, or any combination thereof.

In some embodiments, the CAD system <NUM> is configured to reduce the effects of jitter within the HUD <NUM>. For example, a pilot flying an aircraft through turbulence without a CAD system may notice a "jitter" on the display, where the displayed images and symbology jitters or jumps around compared to the real-world view. The CAD system <NUM> may, through communication with the HUD control module or other componentry that controls the direction of emission of the flight information <NUM> through the relay lens assembly <NUM>, the position of the relay lens assembly <NUM>, or the position of the combiner <NUM>), activate a feedback loop, enabling the HUD display to reposition or scale its image so that it compensated for the observed jitter. This feedback loop may require that the CAD system <NUM> is configured to receive information regarding the direction of emission of the flight information <NUM> through the relay lens assembly <NUM>, the position of the relay lens assembly <NUM>, or the position of the combiner <NUM> in real time.

Claim 1:
A system (<NUM>) comprising:
a head-up display (<NUM>) comprising:
an overhead unit (<NUM>) comprising a relay lens assembly (<NUM>); and
a combiner (<NUM>);
an illuminated reticle (<NUM>) spatially coupled to the relay lens assembly (<NUM>), wherein a movement of the relay lens assembly (<NUM>) results in a commensurate movement of the illuminated reticle (<NUM>), wherein the illuminated reticle (<NUM>) comprises a light emitting diode and a diffuser, wherein the illuminated reticle is configured to emit a light pattern;
an optical sensor (<NUM>) spatially coupled to the combiner (<NUM>) or optically coupled to a mirror (<NUM>) spatially coupled to the combiner (<NUM>), wherein the optical sensor (<NUM>) is configured to detect the light pattern emitted from the illuminated reticle (<NUM>); and
a control module (<NUM>) comprising one or more processors and a memory, wherein the control module is configured to:
receive an input from the optical sensor (<NUM>);
determine a position of the combiner (<NUM>) relative to the relay lens assembly (<NUM>) based on the received input; and
generate an output based on a determined position of the combiner (<NUM>) relative to the relay lens assembly (<NUM>);
characterized in that the system is configured to:
recognize the light pattern and determine an X, Z position of the reticle relative to the position of the sensor; and
determine a distance from the sensor to the reticle based on a dispersion of the light pattern from the reticle.