Patent Application
20230347186
Positive pressure face masks can ensure supply of breathable gas is present in the event the ambient atmosphere becomes unbreathable. For example, a fire in a contained environment such as an aircraft or submarine can rapidly render the atmosphere unbreathable. In addition to being unbreathable, smoke can hinder visibility.
The present disclosure encompasses systems, methods, and an apparatus for providing a display inside a sealed face mask. In general, innovative aspects of the subject matter described in this specification can be embodied a visual display mounting system. The mounting system is configured for mounting a visual display system inside full-face masks and includes a mount and a chassis. The mount includes a first plate and a second plate configured to be attached to a full-face mask. The first plate is configured to be attached externally to a top of the full-face mask, and the second plate is shaped to fit inside the full-face mask. The first plate and second plate are configured to be coupled one to the other through a frame of the full-face mask. The chassis is configured to be suspended from the second plate, when installed in the full-face mask. The chassis supports display optics and electronic circuitry of the visual display system. This and other implementations can each optionally include one or more of the following features.
In some implementations, the chassis is suspended from the second plate by a drive screw and a guide rod. The guide rod can be configured to conduct thermal energy from the electronic circuitry to a fastener in the second plate.
In some implementations, the fastener in the second plate is configured to conduct thermal energy to the first plate.
In some implementations, the visual display system includes a printed circuit board (PCB), one or more light sources, liquid-crystal-on-silicon (LCOS) displays, and partial reflectors enclosed in a metal housing, and the PCB includes a protruding edge in physical contact with and electrically grounded to the metal housing.
Another general aspect can be embodied in a device that includes a full-face mask and a video display system placed inside the full-face mask. The full-face mask is configured to seal against a user's face, when in use, to form a mask cavity, and the mask includes a built-in respirator and a transparent face shield. The visual display system includes display optics and electronic circuitry held in a chassis suspended from a mount secured to the face shield. This and other implementations can each optionally include one or more of the following features
In some implementations, the mount includes a first plate and a second plate. The first plate is mounted above the transparent face shield and external to the full-face mask. The second plate is mounted inside the full-face mask and coupled to a frame of the full-face mask by a plurality of couplers. The second plate is coupled to the first plate through the frame by a plurality of fasteners, where the fasteners form a thermal path for conducting heat generated by the visual display system to the first plate. The chassis is suspended from the second plate.
In some implementations, the chassis is suspended from the second plate by a drive screw and a guide rod, where the guide rod is configured to conduct thermal energy from the electronic circuitry to the fasteners in the second plate.
In some implementations, the fasteners in the second plate are configured to conduct thermal energy to the first plate.
In some implementations, the visual display system includes a printed circuit board (PCB), one or more light sources, liquid-crystal-on-silicon (LCOS) displays, and partial reflectors enclosed in a metal housing. The PCB includes a protruding edge in physical contact with and electrically grounded to the metal housing.
In some implementations, the chassis is suspended from and vertically movable relative to the mount via a drive screw.
In some implementations, the drive screw engages with a nut made from a self-lubricating material.
In some implementations, the drive screw has four or more threads.
In some implementations, the drive screw has eight threads.
In some implementations, the respirator is connected to an oxygen or purified-air supply hose.
In some implementations, the display optics include light sources, liquid-crystal-on-silicon (LCOS) displays, partial reflectors, and combiners configured to combine light received through the face shield with an image from the LCOS displays along optical axes aligned, when in use, with the user's eyes.
In some implementations, the display optics includes stretched-film reflective polarizers in a path between the light sources and the LCOS displays.
In some implementations, the chassis includes holes serving as alignment features during assembly of the device and as venting paths during use of the device.
Another general aspect can be embodied in a device that includes a full-face mask, a visual display system, and a visual display controller. The full-face mask is configured to seal against a user's face, when in use, to form a mask cavity, and the mask includes a transparent face shield and a built-in respirator connected to an oxygen or purified-air supply hose. The visual display system is placed inside the mask cavity and includes display optics and electronic circuitry held in a chassis. The visual display controller is mounted on the oxygen or purified-air supply hose. The visual display controller includes a plurality of user input elements for user control of the visual display system. These and other implementations can each optionally include one or more of the following features.
In some implementations, the user input elements include a display switch, a power switch, and brightness adjustment buttons.
In some implementations, the user input elements include at least one of tactile or haptic distinguishing features.
In some implementations, the visual display controller includes one or more LED indicators each includes an associated crossed-polarizer dimmer.
In some implementations, the device includes a triaxial cable connected to the electronic circuitry to provide power, control signals, video data to the visual display system.
In some implementations, the triaxial cable includes braided wires surrounding a microcoaxial cable.
In some implementations, the device a video converter connected to the electronic circuitry via the triaxial cable, where the video converter is configured to convert a video feed into a gigabit serial link signal.
In some implementations, the device includes a coaxial cable connected to the electronic circuitry to provide power, control signals, video data to the visual display system. The coaxial cable includes an outer radio frequency (RF) shield, where the outer RF shield is connected to ground.
The details of these and other aspects are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
This disclosure describes a display and mounting system for a display to be integrated into a positive pressure mask. In certain enclosed environments, emergency masks are used as a backup source of breathable atmosphere in the event the regular atmosphere becomes unusable. For example, a fire in an aircraft can rapidly render the internal volume of the aircraft unsuitable for breathing. In these instances, emergency masks can be provided which form a seal with the user's face and provide an independent breathable atmosphere. For example, an MF20-004 mask is a full-face, positive pressure, oxygen mask that allows the user to breathe independently of the ambient atmosphere. While the mask may enable breathing, smoke or other environmental factors may inhibit visibility. In the aircraft example, it may be imperative that a pilot have access to certain information (e.g., airspeed, attitude, altitude, etc.) even when visibility in the cockpit is obstructed. This disclosure provides an in-mask display, and mounting system to provide critical information to the user, regardless of visibility external to the mask.
Since the in-mask display is located near the user's eyes (within the mask) it should be adjustable to conform to users with different facial structures. A mechanism is provided to allow the display to be translated vertically within the mask, allowing the user to align the display with their eyes. The display must also be mounted in a manner that minimizes mask penetrations (and therefore possible leak points) and conducts heat generated by the display outside of the mask.
While the present disclosure describes the in-mask display system in the context of an aircraft pilot's mask, the disclosed displays system is also useful for masks used in other contexts. For example, the in-mask display system described herein can be incorporated into other sealed face masks e.g., firefighter masks or dive masks.
Display system 102 is mounted inside a cavity 103 of the mask, and can be configured to be positioned in front of the user's eyes. For example, the cavity 103 may be formed between the face shield (shown as 904 in
In some implementations, a controller 108 is provided to permit the user to interact with the display system 102. The illustrated controller 108 in
External plate 212 can be mounted to the internal plate 210, outside of the seal of the mask, and can include electronics and other components necessary to operate the display system 102. Some implementations, include electronic components in the external plate 212 which generate significant heat or use larger voltages/currents. The inside of the mask can be a pure oxygen environment, and so to avoid sparking or other flammability concerns, certain circuitry can be included in the external plate 212 outside of the mask. In some implementations, video and/or telemetry data from external to the mask (e.g., from an aircraft) is provided via the umbilical (e.g., umbilical 106 as described with reference to
The chassis 202 houses additional circuitry for generating images on the display lenses 204. It is suspended from the internal plate 210 via a height adjustor 208. The height adjustor 208 can be implemented as a worm gear that is rotatably mounted to the internal plate 210. When the height adjustor 208 rotates, its threads engage with channels in the chassis 202 causing the entire chassis 202 to translate up or down depending on the direction of rotation. In some implementations, the height adjustor 208 engages with, or is formed of a self-lubricating material (e.g., a high density polyethylene) which reduces wear and risk of spark or arc. In some implementations, the height adjustor 208 is an 8 toothed worm gear. For example, an 8-toothed worm gear provides significant vertical displacement of the chassis 202 with minimal rotation (e.g., approximately 45 degrees of rotation provides approximately 1-2 inches of vertical displacement). Other implementations, can include a height adjustor with 4-10 teeth.
Guide rods 206 are provided to ensure the chassis 202 stays aligned with the user's face as it translates, and to assist in conducting heat from the chassis 202 to the internal plate 210. The chassis 202 can include a shroud, or outer shell, which generally encloses the additional circuitry and at least a portion of the display lenses 204. In some implementations the shroud includes an aluminum alloy that is beneficial for heat transfer from internals of the display system 102, as well as reduction in electromagnetic interference (EMI). In certain instances, the shroud is an anodized aluminum alloy. In some implementations, the shroud is a magnesium alloy. Heat generating components inside the chassis 202 can be thermally coupled to the shroud to encourage rapid heat dissipation and transfer out of the display system 102.
The display lenses 204 receive an image and redirect it toward the user's eyes. In some implementations, the display lenses also allow external light to pass through, providing the projected image as an overlay to what the user would normally see.
The external plate 212 can be formed of an aluminum alloy, and act as a heat sink for thermal energy generated in the display system (e.g., display system 102 of
The internal plate 210 includes thermally conductive fasteners 402. The thermally conductive fasteners 402 can mount to the external plate 212 and provide good heat transfer between the internal plate 210 and the external plate 212. In certain instances, the thermally conductive fasteners 402 are an aluminum alloy, a ceramic material, graphite, carbon impregnated rubber material, or other material with high thermal conductivity. In the illustrated example, the thermally conductive fasteners 402 include a threaded slot underneath (not shown) where a guide rod (e.g., guide rod 206 of
Internal plate 210 can include a cable port 404, which allows a data and communications cable (e.g., triaxial cable) to pass from the external plate 212 through the internal plate 210 to the display system. The cable port 404 can include packing material, or one or more seals to reduce or prevent gas passing through the cable port 404. In some instances a single, combined data and power cable passes from the umbilical through the external plate 212 and internal plate 210 to the display system. The cable can transmit a low-power, signal for images or video. For example the cable can transmit a gigabit serial link data which allows high-speed, high-bandwidth, two way communication using a single, EMI resistant cable. The cable can be, for example, a triaxial cable or a coaxial cable with additional braided wires surrounding the coaxial cable. In some implementations the cable includes multiple twisted pairs. In some implementations, the cable includes an outer radio frequency (RF) shield coupled to ground.
The central PCB includes an exposed strip 508 in the illustrated example which can be in electrical contact with a shroud of the chassis, ensuring the display system and structural components are electrically grounded. The exposed strip 508 can form a protruding edge from the rest of the PCB, and make physical contact with the shroud. Heat generating components in circuitry 502 can be thermally coupled to the shroud (e.g., via heat pipes, thermal paste, or other connection) and the shroud can be in contact with the guide rods, providing a thermal connection from the circuitry 502, to the external plate 216 as discussed above.
The projectors 506 each include one or more displays, LED backlights, and one or more lenses for projecting an image onto the optical flow path 504. The optical flow path 504 is a path in which the projected image takes from the projector, through one or more lenses, and reflecting off one or more reflectors to the user's eyes. The displays in the projectors 506 can be liquid crystal on silicon (LCOS) displays. LCOS displays are advantageous in that they can have a small form factor, and relatively low power consumption compared to other projector displays.
In some implementations, the reflector 602 can be a stretched film polarizer. Stretched film polarizers are a type of reflective polarizer. Due to the properties of using an LCOS, which initially encodes the image in polarization state, some element in the optical path must have a polarization dependent property, so that the polarized image light is separated from the non-image light (e.g., ambient imagery 610). The stretched film polarizer achieves this need, while being easier to manufacture, and far less fragile, compared to alternatives.
The controller 108 can include one or more status indicators 704, which can be LED lights or other indicators that indicate, for example, battery charge, data connectivity, or other important factors to ensure the mask and in-mask display are ready to operate. In some implementations, the LED indicators have an associated crossed-polarizer dimmer. For example, the crossed-polarizer dimmer(s) may be used to reduce the brightness of the LED light output.
