Integrated display for sealing mask
By installing a visual display system inside the positive pressure mask, the problem of reduced visibility caused by smoke and non-breathable gases in a closed environment is solved, and the function of providing key information to users in emergencies is realized.
Patent Information
- Application Number
- CN202380046820.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-04-27
- Filing Date
- 2023-04-25
- Publication Date
- 2025-02-07
AI Technical Summary
In a closed environment, smoke outside the mask and non-breathable gas will lead to reduced visibility, making it difficult for users to obtain important information in emergencies such as aircraft.
A visual display system for the interior of a positive pressure mask is designed, including a mounting piece and a chassis, which is suspended from a second plate, supports the display optics and electronic circuits, and conducts heat to the outside of the mask through a guide rod.
It is realized that critical information is provided to users when the external visibility of the mask is reduced, ensuring that the aircraft and other equipment can be operated safely in an emergency.
Smart Images
Figure CN119403600A_ABST
Abstract
Description
Background Art
[0001] Positive pressure masks can ensure that there is a supply of breathable gas in the event that the ambient atmosphere becomes unbreathable. For example, a fire in a confined environment such as an aircraft or submarine can quickly make the atmosphere unbreathable. In addition to being unbreathable, smoke can also impede visibility. Summary of the invention
[0002] The present disclosure covers systems, methods, and apparatus for providing a display inside a sealing mask. In general, the innovative aspects of the subject matter described in this specification can be embodied as a visual display mounting system. The mounting system is configured to mount a visual display system inside a full face mask and includes a mounting member and a chassis. The mounting member includes a first plate and a second plate configured to be attached to the full face mask. The first plate is configured to attach to the top of the full face mask from the outside, and the second plate is formed to fit inside the full face mask. The first plate and the second plate are configured to be connected to each other by 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 the display optics and electronic circuits of the visual display system. This embodiment and other embodiments can each optionally include one or more of the following features.
[0003] In some embodiments, the chassis is suspended from the second plate by drive screws and guide rods. The guide rods can be configured to conduct heat energy from the electronic circuit to the fasteners in the second plate.
[0004] In some implementations, the fasteners in the second plate are configured to conduct thermal energy to the first plate.
[0005] In some embodiments, a visual display system includes a printed circuit board (PCB), one or more light sources, a liquid crystal on silicon (LCOS) display, and a partial reflector encapsulated in a metal housing, and the PCB includes a protruding edge that is physically in contact with the metal housing and electrically grounded to the metal housing.
[0006] Another general aspect can be embodied in a device that includes a full face mask and a video display system disposed within the full face mask. The full face mask is configured to seal against the face of a user to form a mask cavity when in use, 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 that is suspended from a mount secured to the mask. This embodiment and other embodiments can each optionally include one or more of the following features:
[0007] In some embodiments, the mounting member includes a first plate and a second plate. The first plate is mounted above the transparent face shield and outside the full face mask. The second plate is mounted within the full face mask and coupled to the 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, wherein 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.
[0008] In some embodiments, the chassis is suspended from the second plate by drive screws and guide rods, wherein the guide rods are configured to conduct thermal energy from the electronic circuit to the fasteners in the second plate.
[0009] In some implementations, the fasteners in the second plate are configured to conduct thermal energy to the first plate.
[0010] In some embodiments, the visual display system includes a printed circuit board (PCB), one or more light sources, a liquid crystal on silicon (LCOS) display, and a partial reflector enclosed in a metal housing. The PCB includes a protruding edge that is in physical contact with the metal housing and is electrically grounded to the metal housing.
[0011] In some embodiments, the chassis is suspended from the mount via drive screws and is vertically movable relative to the mount.
[0012] In some embodiments, the drive screw engages a nut made of a self-lubricating material.
[0013] In some embodiments, the drive screw has four or more threads.
[0014] In some embodiments, the drive screw has eight threads.
[0015] In some embodiments, the respirator is connected to an oxygen or purified air supply hose.
[0016] In some implementations, the display optics include a light source, a liquid crystal on silicon (LCOS) display, a partial reflector, and a combiner configured to combine light received through the mask with an image from the LCOS display along an optical axis that is aligned with the user's eyes when in use.
[0017] In some implementations, the display optics include a stretched film reflective polarizer in a path between the light source and the LCOS display.
[0018] In some embodiments, the chassis includes a hole that serves as an alignment feature during assembly of the device and as a vent path during use of the device.
[0019] Another general aspect can be embodied in an apparatus including a full face mask, a visual display system, and a visual display controller. The full face mask is configured to seal against the user's face to form a mask cavity when in use, and the mask includes a transparent mask 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 circuits retained 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 embodiments can each optionally include one or more of the following features.
[0020] In some embodiments, the user input elements include a display switch, a power switch, and a brightness adjustment button.
[0021] In some embodiments, the user input element includes at least one of a tactile or a tactile-differentiating feature.
[0022] In some implementations, the visual display controller includes one or more LED indicators, each LED indicator including an associated cross-polarizer dimmer.
[0023] In some embodiments, the device includes a triaxial cable connected to the electronic circuit to provide power, control signals, and video data to the visual display system.
[0024] In some implementations, the triax cable includes a braided wire surrounding a micro-coaxial cable.
[0025] In some implementations, the device includes a video converter connected to the electronic circuit via a triax cable, wherein the video converter is configured to convert the video feed to a gigabit serial link signal.
[0026] In some embodiments, the device includes a coaxial cable connected to the electronic circuit to provide power, control signals, video data to the visual display system. The coaxial cable includes an outer radio frequency (RF) shield, wherein the outer RF shield is grounded.
[0027] The details of these and other aspects are set forth in the accompanying drawings and the description that follows.Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1A and 1B An example mask with an internal display system and controller is shown.
[0029] Figure 2 is a front view of the internal display and mounting system for the mask.
[0030] Figure 3 is a side view of an internal display and mounting system for a face mask.
[0031] Figure 4 Illustration of a mounting plate for an in-hood display system
[0032] Figure 5A and Figure 5B A partial schematic diagram of an in-hood display system is shown, showing some of the optical components from a front view, and a top perspective view.
[0033] Figure 6 is a diagram showing the light flow path of the in-cover display system.
[0034] Fig. 7A is a front view of the cover in the storage box with the controller exposed.
[0035] Figure 7B is a side-facing illustration of the cover in a storage box with the controller exposed.
[0036] Fig. 8A and 8B A perspective view of an exemplary connector for connecting an inner plate of a mounting system to a mask is shown.
[0037] Fig. 9 is a perspective view of the face shield with the inner plate of the display mounting system attached. DETAILED DESCRIPTION
[0038] The present disclosure describes a display and a mounting system for integrating the display into a positive pressure mask. In certain closed environments, emergency masks are used as a backup source of breathable atmosphere in the event that the conventional atmosphere becomes unavailable. For example, a fire in an aircraft can quickly make the internal volume of the aircraft unsuitable for breathing. In these cases, an emergency mask can be provided that forms a seal with the user's face and provides an independent breathable atmosphere. For example, the MF20-004 mask is a full-face positive pressure oxygen mask that allows the user to breathe the atmosphere independently of the environment. Although the mask can achieve breathing, smoke or other environmental factors may inhibit visibility. In the aircraft example, it is necessary that the pilot can access certain information (e.g., airspeed, attitude, altitude, etc.) even when visibility in the cockpit is blocked. The present disclosure provides an in-mask display and mounting system to provide key information to the user regardless of visibility outside the mask.
[0039] Since the in-mask display is located near the user's eyes (inside the mask), it should be adjustable to conform to users with different facial structures. A mechanism is provided to allow the display to translate 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 penetration (and therefore possible leak points) and conducts heat generated by the display to the outside of the mask.
[0040] Although the present disclosure describes the in-mask display system in the context of an aircraft pilot's mask, the disclosed display system can also be used for masks used in other contexts. For example, the in-mask display system described herein can be incorporated into other sealing masks, such as firefighter masks or diving masks.
[0041] Figure 1A and 1B An example mask 104 with an internal display system 102 and a controller 108 is shown. The full face mask 104 includes a seal that surrounds the user's eyes, nose, and mouth and prevents or reduces gas exchange between the environment inside the mask and the external environment. In some embodiments, the full face mask 104 is a MF20-004 mask. The umbilical cable 106 delivers a pressurized gas supply (e.g., compressed air or oxygen) that pressurizes the interior of the mask. The breathable gas supply can be provided to a respirator 110 that can control the flow of gas according to the user's breathing needs. In some embodiments, an exhaust valve (not shown) near the top of the mask allows excess gas (e.g., gas exhaled from the user) to escape the mask while ensuring that external gas does not penetrate into the mask. In addition to delivering pressurized breathable gas, the umbilical cable 106 may also include one or more data cables 107 that carry communications and / or power to control systems associated with the mask and / or display system 102.
[0042] The display system 102 is mounted in the cavity 103 of the mask and can be configured to be positioned in front of the user's eyes. For example, the cavity 103 can be formed in the face shield of the mask (at Figure 4 904) and the user. In the illustrated example, the display system 102 is a transparent heads-up display (HUD) that displays images, data, or both while also allowing the user to see through the display. In some embodiments, the display system 102 can be a solid screen where an external (e.g., forward-facing) camera is used to provide perspective. In some embodiments, the display system 102 can be positioned over only one eye of the user. The display system 102 is highly adjustable, allowing the user to align it with their eye. Figure 3 Height adjustment is discussed in more detail. The mask 104 and display system 102 and controller 108 together are configured to weigh less than 2.3 pounds.
[0043] In some implementations, a controller 108 is provided to allow a user to interact with the display system 102 . Figure 1B The controller 108 shown in FIG. 1 includes several user controls, including, but not limited to, a power button, a display button, and brightness increase and decrease buttons. User controls are typically physical, tactile input elements and may include buttons, rocker switches, membrane switches, rotary switches, slide switches, toggle switches. The display button may be used to cycle through various menus or options within a graphical user interface in the display system 102. In some embodiments, the controller 108 includes a plurality of user controls, including, but not limited to, a power button, a display button, and brightness increase and decrease buttons. The user controls are typically physical, tactile input elements and may include buttons, rocker switches, membrane switches, rotary switches, slide switches, toggle switches. The display button may be used to cycle through various menus or options within a graphical user interface in the display system 102. Figure 1B In some embodiments, the controls may include more or fewer controls than those shown in FIG. Moreover, the controls on the controller 108 are not limited to buttons. The controls may include triggers, knobs, dials, touch screens, or other input devices. In some embodiments, the controls may include tactile features 109 on or near the controls that distinguish one control button / switch from another. For example, Figure 1B The illustrated controller 108 depicts embossed "+" and "-" symbols next to a brightness control button.
[0044] Figure 2 2 is a front view of an internal display and mounting system for a mask. The display system 102 includes a chassis 202 suspended from an inner plate 210 by a height adjuster 208 and one or more guide rods 206. The inner plate 210 is mounted on the inside of the mask to an outer plate 212 located on the outside of the mask. The inner plate 210 can be mounted to the mask frame 105 by one or more sealing penetrations or other fastening means. The inner plate 210 is coupled to the inside of the mask 104 using a connector 214. Fig. 8A and 8B A perspective view of an exemplary connector 214 is shown. The connector 214 is attached to the inner panel 210 at a connection point 216. The connector 214 includes a head 802 configured to connect to the inside of the mask frame 105 and a groove (e.g., a half dovetail) 804, the head 802 being configured to connect to the inside of the mask frame 105, and the groove 804 being configured to mate with a corresponding tab 408 ( Figure 4 For example, the connector 214 passes through the existing rivet hole 902 in the mask 104 and clips to the connection point 216 on the inner panel 210 (as shown in FIG. Fig. 9 ). The outer plate 212 and the inner plate 210 can be screwed together at the top with the existing silicone seal of the mask 104 therebetween. The silicone seal can be used as an intrusion protection. As described in more detail below and with reference to Figure 4 , the inner plate 210 can provide heat transfer from the chassis 202 to the outer plate 212.
[0045] The outer panel 212 may be mounted to the inner panel 210, outside the seal of the mask, and may include the electronics and other components required to operate the display system 102. Some embodiments include electronic components in the outer panel 212 that generate significant heat or use greater voltage / current. The interior of the mask may be a pure oxygen environment, and therefore to avoid sparks or other flammability issues, certain circuits may be included in the outer panel 212 outside the mask. In some embodiments, video and / or telemetry data from outside the mask (e.g., from an aircraft) is provided to the circuits in the outer panel 212 via an umbilical cable (e.g., an umbilical cable 106 as described with reference to FIG. 1), where the video and / or telemetry data is converted to a low-power proprietary format to be transmitted to the mask via a single cable (e.g., a triaxial cable). In some cases, the video and / or telemetry data is provided in a low-power proprietary format via one or more data cables 107 of the umbilical cable 106, and does not need to be converted by the display system 102 until it is rendered to the display lens 204. External panel 212 may include a data cable connection 213 that may be connected to a data cable (eg, data cable 107 of FIG. 1 ).
[0046] The chassis 202 houses additional circuitry for generating an image on the display lens 204. It is suspended from the inner plate 210 via a height adjuster 208. The height adjuster 208 can be implemented as a worm gear rotatably mounted to the inner plate 210. When the height adjuster 208 rotates, its threads engage with the channels in the chassis 202, causing the entire chassis 202 to translate upward or downward depending on the direction of rotation. In some embodiments, the height adjuster 208 is engaged with or formed of a self-lubricating material (e.g., high-density polyethylene), which reduces wear and the risk of sparks or arcs. In some embodiments, the height adjuster 208 is an 8-tooth worm gear. For example, an 8-tooth worm gear provides a significant vertical displacement of the chassis 202 with minimal rotation (e.g., a rotation of approximately 45 degrees provides a vertical displacement of approximately 1-2 inches). Other embodiments may include a height adjuster with 4-10 teeth.
[0047] Guide rods 206 are provided to ensure that the chassis 202 remains aligned with the user's face as it translates, and to help conduct heat from the chassis 202 to the inner plate 210. The base 202 may include a shield or housing that typically surrounds additional circuitry and at least a portion of the display lens 204. In some embodiments, the shield includes an aluminum alloy that facilitates heat transfer from the interior of the display system 102 and reduces electromagnetic interference (EMI). In some cases, the shield is an anodized aluminum alloy. In some embodiments, the shield is a magnesium alloy. Heat-generating components within the chassis 202 may be thermally coupled to the shield to facilitate rapid heat dissipation and transfer out of the display system 102.
[0048] The display lens 204 receives the image and redirects it toward the user's eyes. In some embodiments, the display lens also allows external light to pass through, thereby providing the projected image as an overlay of what the user would normally see.
[0049] Figure 3 2 is a side view of an internal display and mounting system for a mask. In the side view, a height adjustment lever 302 is visible. The height adjustment lever 302 allows the user to manually rotate the height adjuster 208 and align the display lens 204 with their eyes. In some embodiments, the height adjustment can be automatic, and a sensor (e.g., a camera) in the chassis 202 can detect the position of the user's eyes and automatically rotate the height adjuster 208 to align with the detected eye position.
[0050] Figure 4 2 is an illustration of mounting plates for an in-mask display system. Inner plate 210 and outer plate 212 are configured to clamp the frame of the mask. In some cases, the plates are screwed together with sealing screws at penetrations in the mask seal. In some embodiments, the penetrations serve as exhaust devices for the positive pressure environment inside the mask.
[0051] The outer plate 212 may be formed of an aluminum alloy and serves as a heat sink for thermal energy generated in a display system (e.g., the display system 102 of FIG. 1 ). In some embodiments, the outer plate 212 includes fins, channels, or other surface area enhancing features (not shown) that improve the plate's ability to transfer heat away from the housing.
[0052] The inner plate 210 includes a thermally conductive fastener 402. The thermally conductive fastener 402 can be mounted to the outer plate 212 and provide good heat transfer between the inner plate 210 and the outer plate 212. In some cases, the thermally conductive fastener 402 is an aluminum alloy, a ceramic material, graphite, a carbon impregnated rubber material, or other material with high thermal conductivity. In the example shown, the thermally conductive fastener 402 includes a threaded groove (not shown) below, a guide rod (e.g., Figure 2 The guide rod 206 of the heat conductive fastener 402 can be screwed into the thread groove. The heat conductive guide rod provides a heat path from the display system through the guide rod and the heat conductive fastener 402 to the outer plate 212.
[0053] The inner plate 210 may include a cable port 404 that allows data and communication cables (e.g., three coaxial cables) to pass from the outer plate 212 through the inner plate 210 to the display system. The cable port 404 may include a filler material or one or more seals to reduce or prevent gas from passing through the cable port 404. In some instances, a single combined data and power cable passes from the umbilical cable through the outer plate 212 and the inner plate 210 to the display system. The cable can transmit low-power signals for images or videos. For example, the cable can transmit gigabit serial link data, which allows high-speed, high-bandwidth, bidirectional communication using a single EMI-resistant cable. The cable can be, for example, a three coaxial cable or a coaxial cable with an additional braided wire around the coaxial cable. In some embodiments, the cable includes a plurality of twisted pairs. In some embodiments, the cable includes an external radio frequency (RF) shield connected to ground.
[0054] Figure 5A and Figure 5B A partial schematic diagram of an in-mask display system is shown, showing some components from a front view and a top perspective. The in-mask display system 102 includes a circuit 502 that converts a signal received in a cable into an optical image to be projected into the user's eyes. The circuit 502 may include, but is not limited to, a projector 506, a display buffer memory, a voltage regulator, a serializer / deserializer chip for multiplexing and demultiplexing a gigabit serial link signal, a microcontroller unit, or other integrated circuit components. The circuit 502 may be arranged on one or more printed circuit boards (PCBs). In the example shown, three PCBs are provided, one PCB for each projector, and a central PCB includes other components (display buffer, voltage regulator, serializer / deserializer chip, microcontroller, etc.).
[0055] In the illustrated example, the center PCB includes an exposed strip 508 that can be in electrical contact with the shield of the base, thereby ensuring that the display system and structural components are electrically grounded. The exposed strip 508 can form an edge that protrudes from the rest of the PCB and is in physical contact with the shield. The heat-generating components in the circuit 502 can be thermally coupled to the shield (e.g., via a heat pipe, thermal paste, or other connection), and the shield can be in contact with the guide rods, thereby providing a thermal connection from the circuit 502 to the outer plate 216, as described above.
[0056] Projectors 506 each include one or more displays, LED backlights, and one or more lenses for projecting images onto light flow paths 504. Light flow paths 504 are paths for projected images from the projector through one or more lenses and reflected from one or more reflectors to the user's eyes. The displays in projectors 506 can be liquid crystal on silicon (LCOS) displays. LCOS displays are advantageous because they can have a small form factor and have relatively low power consumption compared to other projector displays.
[0057] Figure 6 is a diagram showing an example optical flow path for an in-hood display system. A projector 506 generates an optical image that travels along an optical flow path 504 to one or more reflectors 602, which reflect the optical image downward to a power lens 604. The power lens 604 collimates and focuses the optical image into a combiner 606, which reflects the projected optical image projection energy 608 to the user's eyes. In addition, the combiner 606 allows an ambient image 610 to pass through, which is combined with the projected image 608 to provide a HUD style display to the user, where the projected image overlaps with what the user sees through the front of the mask.
[0058] In some implementations, reflector 602 can be a stretch film polarizer. A stretch film polarizer is a type of reflective polarizer. Due to the nature of using LCOS that initially encodes an image in polarization state, some element in the optical path must have polarization-dependent properties so that polarized image light is separated from non-image light (e.g., ambient image 610). Stretch film polarizers accomplish this need while being easier to manufacture and less fragile than alternatives....
[0059] Fig. 7A and 7B is an illustration of a mask in a storage box with exposed controls. In some instances, it is necessary to perform routine maintenance and activity checks on the mask and the in-mask display. The mask can be stored in a storage box 702 with the controls mounted to the front of the box. In some embodiments, the controls are stored within the box but positioned so that their face is visible from outside the box. Providing maintenance without removing the mask from its storage box 702 reduces wear and tear on the mask and extends the life of the mask, and reduces maintenance time.
[0060] The controller 108 may include one or more status indicators 704, which may be LED lights or other indicators to indicate, for example, battery charge, data connectivity, or other important factors to ensure that the mask and in-mask display are ready for operation. In some embodiments, the LED indicators have associated cross-polarizer dimmers. For example, the cross-polarizer dimmers may be used to reduce the brightness of the LED light output.
Claims
1. A visual display mounting system, the visual display mounting system being configured for mounting a visual display system inside a full face mask, the visual display mounting system comprising: a mounting member comprising a first plate and a second plate, the first plate and the second plate being configured to attach to a full face mask, the first plate being configured to attach to a top portion of the full face mask from the outside, the second plate being shaped to fit inside the full face mask, wherein the first plate and the second plate are configured to couple to each other via a frame of the full face mask; and A chassis is configured to be suspended from the second plate when installed in the full face mask, the chassis supporting display optics and electronic circuitry of the visual display system.
2. The system according to claim 1, wherein: The chassis is suspended from the second plate by drive screws and guide rods, wherein the guide rods are configured to conduct thermal energy from the electronic circuit to fasteners in the second plate.
3. The system according to claim 2, wherein: The fasteners in the second plate are configured to conduct thermal energy to the first plate.
4. A system according to claim 2, wherein the visual display system includes a printed circuit board (PCB), one or more light sources, a liquid crystal on silicon (LCOS) display and a partial reflector encapsulated in a metal shell, and the PCB includes a protruding edge that is physically in contact with the metal shell and electrically grounded to the metal shell.
5. A device comprising: a full face mask configured to seal against a user's face to form a mask cavity when in use, the mask comprising a built-in respirator and a transparent face shield; and A visual display system is positioned within the mask cavity, the visual display system including display optics and electronic circuitry held in a chassis suspended from a mount secured to the mask.
6. The device according to claim 5, wherein: The mounting member comprises: a first panel mounted above the transparent face shield and external to the full face mask; and a second plate mounted inside the full face mask and coupled to a frame of the full face mask by a plurality of couplers, the second plate coupled to the first plate via the frame by a plurality of fasteners, the fasteners forming a thermal path for conducting heat generated by the visual display system to the first plate, the chassis being suspended from the second plate.
7. The device according to claim 6, wherein: The chassis is suspended from the second plate by drive screws and guide rods, wherein the guide rods are configured to conduct heat energy from the electronic circuit to the fasteners in the second plate, wherein the fasteners in the second plate are configured to conduct thermal energy to the first plate, and The visual display system includes a printed circuit board (PCB), one or more light sources, a liquid crystal on silicon (LCOS) display and a partial reflector encapsulated in a metal shell, wherein the PCB includes a protruding edge that is in physical contact with the metal shell and electrically grounded to the metal shell.
8. The device according to claim 5, wherein: The chassis is suspended from the mount via a drive screw and is vertically movable relative to the mount.
9. The device according to claim 8, wherein: The drive screw engages with a nut made of a self-lubricating material.
10. The device of claim 8, wherein the drive screw comprises four or more threads.
11. The device of claim 10, wherein the drive screw comprises eight threads.
12. The apparatus of claim 5, wherein the respirator is connected to an oxygen or purified air supply hose.
13. The apparatus of claim 5, wherein the display optics comprises a light source, a liquid crystal on silicon (LCOS) display, a partial reflector, and a combiner configured to combine light received through the mask with an image from the LCOS display along an optical axis that, when in use, is aligned with an eye of the user.
14. The apparatus of claim 13, wherein the display optics further comprises a stretched film reflective polarizer in a path between the light source and the LCOS display.
15. The apparatus according to claim 5, wherein: The chassis includes holes that serve as alignment features during assembly of the device and as vent paths during use of the device.
16. A device comprising: a full face mask configured to seal against the user's face to form a mask cavity when in use, the mask comprising a transparent face mask and a built-in respirator connected to an oxygen or purified air supply hose; a visual display system disposed inside the mask cavity, the visual display system comprising display optics and electronic circuitry retained in a chassis; and A visual display controller mounted on the oxygen or purge air supply hose, the visual display controller including a plurality of user input elements for user control of the visual display system.
17. The apparatus according to claim 16, wherein: The user input elements include a display switch, a power switch and a brightness adjustment button.
18. The apparatus according to claim 16, wherein: The user input element includes at least one of a tactile or a tactile-distinguishing feature.
19. The apparatus according to claim 16, wherein: The visual display controller includes one or more LED indicators, each LED indicator including an associated cross-polarizer dimmer.
20. The apparatus of claim 16, further comprising a triaxial cable connected to the electronic circuit to provide power, control signals, and video data to the visual display system.
21. The apparatus of claim 20, wherein the triaxial cable comprises a braided wire surrounding a micro-coaxial cable.
22. The device of claim 20, further comprising a video converter connected to the electronic circuit via the triax cable, the video converter configured to convert a video feed to a gigabit serial link signal.
23. The apparatus of claim 16, further comprising a coaxial cable connected to the electronic circuit to provide power, control signals, and video data to the visual display system, the coaxial cable comprising an external radio frequency (RF) shield, wherein the external RF shield is grounded.