Seat power supply and display system

Abstract

The light assembly, particularly for providing an in-use indicator for an in-seat power supply (e.g., on an aircraft), comprises a light emitting device (e.g., one or more LEDs) contained in a housing engageable with an opening in a seat spar, the housing comprising one or more lens assemblies arranged in use to direct light from the light emitting device along an interior of the seat spar to an end thereof. Embodiments comprise an overmoulded rear shell configured to conform to the seat spar for correct alignment of the light assembly and to provide a seal against moisture ingress. Also claimed is a seat comprising the light assembly mounted in an opening in a spar of the seat, and a display assembly at an end of the spar. In use, light reaching the display assembly along the interior of the seat spar is displayed to a viewer.

Description

The present invention relates to an assembly and method for providing a display on a seat, allowing information regarding the function and / or status of systems in the seat to be displayed to a viewer. In one embodiment, the assembly provides an In-Use indicator for indicating when a power is being drawn from the in-seat power supply system, for example by a person using their personal electronic device (PED). Background The travelling public are becoming more reliant on their personal electronic devices (PED’s) for entertainment, payment, ticketing, location services etc. Air travel typically places higher emotional demands on travelling public as a PED without power can lead to significant anxiety or even missed flights etc. The travelling public place demands on carriers of all types to provide connectivity and power so that their journey is issue free wherever possible. Vehicle power systems face being targeted at helping the travelling public by providing charging solutions for the PED’s. However, there is a finite amount of power made available to the passengers of any vehicle such as an aircraft. The limited available power may be controlled to provide a single blanket power scheme for the aircraft for example every outlet is limited to say 10W - 5VDC at 2Amps. For a typical single aisle aircraft providing a single USB outlet for say 190 passengers would see a maximum power demand of 1900W. PED power requirements constantly evolve; USB power provision is currently looking at much higher levels than 10W in some case the limit is 240W. In this case 190 passengers requesting 240W would place a demand on the aircraft for 45600W of power after conversion losses resulting in a power system capable of in excess of 50,000W. A typical single aisle aircraft may provide a maximum of 12000W of power before conversion losses. Due to the restricted power availability classic 10W USB-A devices do not present a difficulty for the installers or the airline. With power provision being increasingly used as a differentiator for seating groups within an aircraft and airlines using power provision as a differentiator effective power utilisation within the passenger environment is becoming a crucial tool within the airlines marketing arsenal. Furthermore there exists a requirement from certain airframe manufacturers, such as Airbus, for organisations installing passenger power within the cabin of an aircraft to provide a visual indicator on the end of each row of seats alongside the aisle / walkway. The purpose of the in-use light is to indicate to cabin crew if the seat mounted power sockets are delivering power to a passenger electronic device (PED). At present the in-use indicators tend to use a method whereby the power system monitors the idle current i.e. the resting power consumed by the seat based power system while it is energised but not delivering power to a PED. This can impose constraints on the providers of the PED connections built into the seat environment. Such constraints can include additional power needed to deliver power over differing lengths of cable connecting the power supply to the outlet; this additional power may exceed the idle current within the power supply. Typically power is delivered to the PED via a number of connected devices. Power might be delivered to the seat or seat group via aircraft mains power ie 110VAC typically using 3 phases. The 3 phase power is converted to a DC voltage. The device used to convert the 3 phase supply to DC is typically known as an In Seat Power Supply (ISPS). The ISPS can support a single seat array or multiple seat arrays. In the event multiple seat arrays are supported the idle current could be easily exceeded without any passenger connecting a PED to the power supply. In a number of existing scenarios the installation may comprise one ISPS per seat array; moreover for front row and emergency rows multiple ISPS units have to be installed. In one embodiment the ISPS delivers the DC at a voltage above the required PED voltage to the outlet where the ISPS DC voltage is converted to the required power format supported by the PED, typically 5VDC but it could be 9VDC, 15VDC or 20VDC. In another embodiment the ISPS is configured to convert the 3 phase supply directly into PED voltage to be delivered to a relatively simple outlet. The outlets typically contain one or more USB sockets; the sockets may be USB type A or USB type C, a combination of both or of a later generation. In addition to the USB socket(s) the outlets may be illuminated typically with light emitting diodes (LED’s). The number of LED’s may be restricted due to the idle current limitations of the ISPS. This restriction can and does impact the design decisions for the outlet itself. In addition, the ISPS provides a connection to the In-Use light and again since the distance to the In-Use light may induce voltage drops along the cable connecting the In-Use light the function of the In-Use light tends to be limited to that of a simple indicator. In the case of a twin aisle aircraft two In-Use lights may be required; one for each end of the seat module. If this is the case the installer most likely needs to increase the wiring harness potentially requiring additional certification increasing the installation costs and project timelines. There exists a need to provide a compliant method to deliver indications of power usage to the cabin crew while providing operational flexibility to power providers and installation organisations engaged in the installation of these system. Furthermore the indications may be used to show the level of power being used and provide valuable in-service power management and deeper operation insights to the airlines themselves. Summary of the invention In one embodiment of the invention a single Light Emitting Diode (LED) is provided mounted within an enclosure. The enclosure provides a prismatic lens to deflect the light emitted from the LED to cause the light path to travel at an angle to the originating light path of the LED. The enclosure may be mounted in a hole cut into the seat spar of the seat module so that the light path is contained within the hollow section of the seat spar. The light travels to the end of the seat spar where it encounters the seat spar end cap. According to a first aspect of the present invention, there is provided a light assembly for mounting in the spar of a seat, the assembly comprising: a light emitting device, preferably comprising one or more light emitting diodes (LED); a housing containing the light emitting device and for engaging with an opening in the seat spar; wherein the housing comprises one or more lens assemblies, each comprising at least one lens, the or each lens assembly arranged to direct light emitted by the light emitting device along the interior of the seat spar to at least one end of the seat spar. In a further aspect, the present invention provides a seat comprising a seat spar; a light assembly according to the first aspect of the present invention mounted in an opening in the seat spar; and a display assembly at an end of the spar, whereby light reaching the display assembly along the interior of the spar from the lighting assembly may be displayed to a viewer. Within the end cap according to one embodiment is mounted a complimentary lens permitting the light path to be displayed outside of the seat spar. The seat spar end cap may simply be provided with a series of holes to allow the light path to be seen through the holes. The holes may be arranged to display a symbol, character, or group of characters representing the ‘ON ’state of the power delivery sequence. The symbol may take the form of a logo representing the brand of the aircraft, the airline, the seat provider, the power provider or any other mark required by the installation. The prismatic lens assembly of another implementation may provide a bidirectional lens arranged to refract the light beam to both ends of the spar tube for a multi-aisle aircraft installation. Furthermore, the directionality of the light beam might be such that the lens provides a general glow within the spar tube. In another embodiment the lens assembly may provide a focusing element to control the light path more precisely and concentrate the light beam to increase the intensity of the light beam itself. In yet another embodiment the light emitting device may comprise array of discrete LED devices that may or may not be of different colours. The colours triggered to indicate different states within the power system within the seat module itself. The LED itself may be a bi-colour or tri-colour device. The housing of one embodiment may provide a mounting function whereby when inserted into the spar tube the lens performs a retention function while simultaneously aligning the LED source with the end cap of the spar tube. The mounting function may be a simple spring clip formed within the material of the housing; it may be an additional component assembled to the housing. The housing may be mounted by the use of mechanical fasteners such as screws or cable ties. The housing may be over-moulded onto the LED and its supporting electronic components. The electronic components may comprise a printed circuit board (PCB). The printed circuit board may provide a conductive method to connect the light assembly to a power source. The conductive method may be a multicore wire permanently attached to the PCB. The wire may be securely attached to the PCB via solder or a discrete connection. The soldered connection or discrete connection may be over moulded at the same time as encapsulating the LED and PCB assembly. In another embodiment a commercially available connector may be provided at the end of the multicore wire. In a preferred embodiment the PCB may be provisioned with a commercial connector to facilitate an incoming wire based connection. The commercially available connector may be optionally over-moulded during the encapsulation of the LED and PCB assembly. The commercially available connector may be secured by a discrete component comprising the housing of the lighting assembly. In a further aspect, the present invention provides a method for providing a display at an end of a spar of a seat, the method comprising: emitting light from a light emitting device disposed within the spar; passing the light through at least one lens to cause the light to travel to the end of the spar; and providing a display whereby light transmitted to the end of the spar is visible from outside the spar by a viewer. In a further aspect, the present invention provides a method for providing a display at each end of a spar of a seat, the method comprising: emitting light from a light emitting device disposed within the spar; passing the light through a lens assembly to cause the light to travel to each end of the spar; and providing a display at each end of the spar whereby light transmitted to the end of the spar is visible from outside the spar by a viewer. In another embodiment the lighting assembly may receive power and signal from the In Seat Power System (ISPS) to indicate to cabin crew the status of the seat power provision and connection of passenger personal electronic devices (PEDs) to the ISPS. In this way, the assembly can be used to provide an In-Use indication for the seat power system. The ISPS may signify connection and usage of PED power using simple power thresholds. The idle current of the power system installed within the seat module may be pre-determined. When the idle current state changes the In-Use light circuitry is enabled to energise the LED within the In-Use light facility. If the idle current lowers this could be interpreted as a failure in the PED connection device causing an error state to be displayed by the In-Use light. Positive changes to the idle current ie increases in power being consumed by the ISPS system may be reflected by a different state being displayed at the In-Use light. In a further embodiment higher power consumption consistent with that used by higher power PED’s specifically, but not exclusively USB-PD devices whereby power greater than 10W typically seen by USB-A enabled devices may cause the In-Use light to change indication to reflect the level at which power is being used. In a further aspect, the present invention provides a method for indicating the level of power consumption from an in seat power supply system (ISPS) of a seat, the method comprising: monitoring the power being consumed by the ISPS; operating a light assembly comprising a light emitting device to emit light, the pattern of the light being selected to indicate the level of power being consumed by the ISPS; emitting the light within a spar of the seat; transmitting the light to at least one end of the spar; and displaying the light at the end of the spar to provide an indication of the level of power being consumed by the ISPS to a viewer. Higher power states identified by combinations of software and electronic circuitry used to monitor power usage in a further embodiment may be made available and recorded for subsequent analysis to enable more targeted power provision within the aircraft such as but not exclusively to enable zonal power control based on actual power usage rather than planned or predicted usage. The power states may further be conveyed to other devices within the passenger power system to provide power automated power management facilities. In a further embodiment electronic circuitry may be employed to sense for a short circuit event. The short circuit event may be at the passenger connector interface where the USB socket itself is compromised due to damage incurred during use, typically referred to as customer induced damage (CID). Short circuits may present themselves by a connection pin or multiple pins crossing and contacting with other connection pins in the USB socket itself. In a further aspect, the present invention provides a method for indicating the failure of an in seat power supply system (ISPS) of a seat, the method comprising: detecting a failure of the ISPS, for example a short circuit or damaged component; operating a light assembly comprising a light emitting device to emit light, the pattern of the light being selected to indicate the failure of the ISPS; emitting the light within a spar of the seat; transmitting the light to at least one end of the spar; and displaying the light at the end of the spar to provide an indication of the failure of the ISPS to a viewer. Electronic circuitry of another embodiment may detect the presence of a USB plug inserted into the passenger outlet socket thereby providing a more dynamic assertion of the insertion of a plug into a socket. In another embodiment electronic circuitry may monitor for over-current situations and curtail the power delivered to the offending device. The over-current situation may in another embodiment simply be a commercial fuse failure of which may be communicated to the ISPS. In another embodiment optical sensing may be employed for the detection of a plug inserted into a socket. A plug when inserted into a socket may cause a variance to the internal reflection of the socket illumination system. Circuitry monitoring the internal reflections may signify to the ISPS the insertion of a plug into a socket. Determination of a physical insertion of a plug into a socket may trigger the In-Use light in accordance with airframe requirements. Signals obtained from circuitry within the component parts of the ISPS may be used to determine operational states of the various hardware components. As with the use of In-Use lights monitoring and reporting of these operational states is a requirement imposed by airframe organisations. Further the term BITE or Built In Test Equipment may be applied to the circuitry and reporting function of said circuitry. In a further embodiment the signals used to change the In-Use light display may be used dynamically within a group of seat modules or across the whole installed system to redirect power as available to satisfy a wider use of higher power PED’s within the limits of the aircraft power architecture. Further, the signals may be aggregated at crew terminals to provide for manual reconfiguration, system monitoring, fault finding and isolation of individual, group or zones of PED outlets. To further aid system availability local fault finding may be enhanced by locally checking for short circuits within the outlets. Short circuits may in one embodiment be reported by affecting the illumination colour of the failed outlet. In another embodiment the fault could be indicated by the In-Use light by displaying a specific colour or by a sequence of on-off pulses or a combination thereof. In another embodiment to help attract attention of maintenance staff the In-Use light could be configured to cause an area illumination to help locate the offending article in the limited time available between aircraft turn-arounds. The area illumination function being initiated by the maintenance team by input of a specific code on the power system management console. The code may be a simple key press or may be activated by inserting a key and arming the maintenance function. In a further embodiment the area illumination may be automatically enabled via a vehicle safety event to enable additional lighting to help evacuate the aircraft. In a further embodiment the illumination may take the form of an arrow or indictor helping to identify the position of the nearest exit. In a further aspect, the present invention provides a method for providing illumination in the region of a seat, the method comprising: operating a light assembly comprising a light emitting device to emit light; emitting the light within a spar of the seat; transmitting the light to at least one end of the spar; and emitting light from the end of the spar to illuminate the region adjacent the seat. In such circumstances wherein the aircrafts power facility may be disabled power for the illumination may be diverted from a device commonly used with ISPS referred to as ‘Hold Up’ facilities. Hold Up facilities are typically required when connecting the aircraft to ground power systems whereby power is transferred from aircraft generated power to ground power systems. Hold Up typically provides power to ensure in-seat computing resources are not disturbed during connection and disconnection from ground power. The accompanying Figures 1 to 4 show the details of one embodiment of a lighting assembly according to the present invention. In particular: Figure 1 shows a side view of the lighting assembly; Figure 2 shows a cross-sectional view of the lighting assembly of Figure 1 along the line X-X; Figure 3 is an exploded perspective view of the components of the lighting assembly of Figure 1; and Figure 4 is a perspective view of the lighting assembly of Figure 1 with arrows indicating the light beams emanating from the lens assembly in opposite directions along the interior of a seat spar.

Claims

1. A light assembly for mounting in the spar of a seat, the assembly5 comprising:a light emitting device, preferably comprising one or more light emitting diodes (LED);a housing containing the light emitting device and for engaging with an opening in the seat spar;10         wherein the housing comprises one or more lens assemblies, eachcomprising at least one lens, the or each lens assembly arranged to direct light emitted by the light emitting device along the interior of the seat spar to at least one end of the seat spar.15   2. A seat comprising a seat spar;a light assembly according to claim 1 mounted in an opening in the seat spar; anda display assembly at an end of the spar, whereby light reaching the display assembly along the interior of the spar from the lighting assembly may be20 displayed to a viewer.

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