U.S. patent application number 12/421668 was filed with the patent office on 2010-10-14 for usb repeater for on board aircraft installations.
This patent application is currently assigned to Thales Avionics, Inc.. Invention is credited to Bradford B. Billings, Bradley Foreman, Joshua Stumpf.
Application Number | 20100262748 12/421668 |
Document ID | / |
Family ID | 42263960 |
Filed Date | 2010-10-14 |
United States Patent
Application |
20100262748 |
Kind Code |
A1 |
Stumpf; Joshua ; et
al. |
October 14, 2010 |
USB REPEATER FOR ON BOARD AIRCRAFT INSTALLATIONS
Abstract
A USB repeater assembly is provided for connecting a vehicle
passenger entertainment system to a seat electronics box that may
be at some distance from the entertainment system. The assembly
comprises a host connector that connects with the seat electronics
box and a device connector that connects with the passenger
entertainment system. The passenger entertainment system comprises
a USB personal control unit. The repeater assembly is housed within
a shell, preferably a hardened one, enclosing a portion of the
connectors as well as USB repeater circuitry and through-connects
for connections associated with other components of the passenger
entertainment system.
Inventors: |
Stumpf; Joshua; (Mission
Viejo, CA) ; Billings; Bradford B.; (Lake Forest,
CA) ; Foreman; Bradley; (Mission Viejo, CA) |
Correspondence
Address: |
DRINKER BIDDLE & REATH LLP;ATTN: PATENT DOCKET DEPT.
191 N. WACKER DRIVE, SUITE 3700
CHICAGO
IL
60606
US
|
Assignee: |
Thales Avionics, Inc.
Irvine
CA
|
Family ID: |
42263960 |
Appl. No.: |
12/421668 |
Filed: |
April 10, 2009 |
Current U.S.
Class: |
710/313 |
Current CPC
Class: |
G06F 13/4045
20130101 |
Class at
Publication: |
710/313 |
International
Class: |
G06F 13/20 20060101
G06F013/20 |
Claims
1. A USB repeater assembly, comprising: a host connector that
connects to a seat electronics box (SEB) associated with a
passenger entertainment system, the host connector comprising: a
plurality of Universal Serial Bus (USB) pins associated with the
USB connection to the PCU; and a plurality of entertainment device
pins associated with other components of the passenger
entertainment system; a device connector that connects to the
passenger entertainment system, the passenger entertainment system
comprising a personal control unit (PCU) configured as a USB
device, the device connector comprising: a plurality of USB pins
associated with a USB connection to the PCU; and a plurality of
entertainment system device pins associated with other components
of the passenger entertainment system; direct connections that
connect the device connector plurality of entertainment system
device pins to the host connector plurality of entertainment device
pins; USB repeater circuitry to which the device connector
plurality of USB pins and the host connector plurality of USB pins
are connected via connectors; and a shell that encloses: at least a
portion of the device connector; at least a portion of the host
connector; the direct connections; and the USB repeater circuitry
and its connectors.
2. The assembly according to claim 1, further comprising a circuit
board comprising: the USB repeater circuitry in a form of an
integrated circuit chip; and the direct connections in a form of
circuit board traces.
3. The assembly according to claim 1, wherein the shell is made of
metal, metalized plastic, or metalized composite that electrically
shields the elements it encloses.
4. The assembly according to claim 3, wherein the shell is made of
aluminum or an aluminum alloy.
5. The assembly according to claim 1, further comprising
electrostatic discharge protection circuitry connected to the USB
pins.
6. The assembly according to claim 1, further comprising noise
filters connected to a PCU power line.
7. The assembly according to claim 6, wherein the noise filters
comprise capacitors connected to ground.
8. The assembly according to claim 6, further comprising a shunt
coil in series with the PCU power line.
9. The assembly according to claim 1, wherein dimensions of the
shell and connectors do not exceed approximately 7.6 cm for a
longest dimension that is a length, approximately 4.2 cm for an
intermediate dimension that is a width, and approximately 1.75 cm
for a shortest dimension that is a height.
10. The assembly according to claim 1, wherein the mass of the
assembly does not exceed approximately 36 g.
11. The assembly according to claim 1, wherein the host connector
and the device connectors are D-shell connectors.
12. The assembly according to claim 11, wherein the host connector
and the device connectors are DB-26 connectors.
13. The assembly according to claim 11, wherein the assembly is
hot-swappable.
14. The assembly according to claim 1 comprising over current sense
circuitry that shuts down the USB device in an over current
situation.
15. The assembly according to claim 14, wherein the over current
situation only involves a USB current exceeding approximately 700
mA.
16. The assembly according to claim 1, wherein circuitry within the
shell is industrial grade circuitry.
Description
BACKGROUND
[0001] The invention relates to human interface devices and
specifically to the connection of a user personal control unit
(PCU) to a controlling seat electronics box (SEB) used on an
in-flight entertainment (IFE) system of an aircraft or an in-travel
system of a vehicle. Specifically, this invention relates to the
data transport mechanism and associated cabling that interfaces
between the human interface device and the SEB.
[0002] An in-flight entertainment (IFE) system (this term, as used
herein, applies to any in-transit vehicle entertainment system),
usually comprises a server or series of servers located in a
common, centralized location on an aircraft that is capable of
distributing multimedia content, and real-time interactive data
(games) to passengers. In these systems, it is common for the
passenger to be provided with a passenger system having a video
display unit (VDU) with a video interface, an audio interface, and
a personal control unit (PCU) that can be used to interact with the
passenger system.
[0003] These systems and associated interfaces require
sophisticated electronics for data delivery between the IFE and the
passenger system. Often the communications link will comprise an
area distribution network (ADN) that handles the transmission of
communications targeted to or originating from a particular area of
the aircraft to a central computer.
[0004] For data that is ultimately targeted to or sent from the
passenger system, it is not unusual to have a substantial amount of
electronic equipment that is required to handle tasks such as
decoding audio and video information, handling game control
information, and the like. Unfortunately, the area in which the
passenger sits is often crowded, and therefore it is advantageous
to have the necessary electronics located away from the seat, but
minimally so, in a seat electronics box (SEB).
[0005] The SEB can be located in an area near a passenger seat, yet
far enough away so that it does not take up valuable room within
the seating area of the passenger. Although for certain purposes it
is desirable to locate the SEB as close to the passenger seat as
possible, for other purposes, it may be desirable to locate the SEB
further away. For example, it may be practical because of cost,
weight, or space savings, to use a quad seat electronics box (QSEB)
that is capable of serving four passenger entertainment systems.
Thus, the SEB may be located further away from the passenger
entertainment system than is desirable to achieve certain
goals.
[0006] One of the components of information handled by the SEB is
the information generated by PCU of the user. The PCU is often, but
not necessarily, a handheld unit. This PCU permits the passenger to
control various aspects of the entertainment system, such as
channel or video-on-demand selection, provide input for video
games, etc.
[0007] It is desirable to use standard communications protocols for
communicating information to and from the PCU, and one such
standard is the Universal Serial Bus (USB) standard. It is thus
advantageous to utilize the USB standard for communicating
information from the PCU to the SEB.
[0008] One problem with the current systems is that USB cables that
are used between the SEB and the PCU are limited to five meters due
to the constraints of USB technology. Although communications
problems due to long-run cabling can be addressed by limiting
disconnects (connectors) and using high quality cables to some
small degree, this does not alleviate the problem of communication
reliability.
[0009] The use of USB repeaters for extending the reach of USB
devices is known. However, these known USB repeaters are generally
somewhat large and heavy and do not have a great deal of robustness
and reliability, particularly for achieving the size and weight
constraints, robustness and reliability as required by the
aerospace regulations, and are not capable of accommodating other
signals.
[0010] What is needed is a reliable mechanism that conforms to
aerospace regulations, and that allows for extending the range of
devices connected via USB and is adapted for the aircraft or
vehicle environment. Specifically, it is desirable to maximize
customer satisfaction when they are using their PCU device to
control the IFE system while at the same time addressing the
concerns of the vehicle owners in minimizing costs associated with
weight, etc.
SUMMARY
[0011] To solve this problem, a USB repeater/hub is provided that
permits extending the length over which USB connected devices can
communicate while at the same time permitting a pass-through of
other signals. The USB bus specification allows for extending the
range, in five meter increments, by using a repeater. By packaging
a USB repeater/hub in the appropriate package, with the appropriate
connectors, a USB repeater can be made that can pass the rigorous
qualification (FAA) requirements for an IFE system.
[0012] Specifically, a USB repeater assembly is provided
comprising: a host connector that connects to a seat electronics
box (SEB) associated with a passenger entertainment system, the
host connector comprising: a plurality of Universal Serial Bus
(USB) pins associated with the USB connection to the PCU; and a
plurality of entertainment device pins associated with other
components of the passenger entertainment system. The assembly
further comprises: a device connector that connects to the
passenger entertainment system, the passenger entertainment system
comprising a personal control unit (PCU) configured as a USB
device, the device connector comprising: a plurality of USB pins
associated with a USB connection to the PCU; and a plurality of
entertainment system device pins associated with other components
of the passenger entertainment system; direct connections that
connect the device connector plurality of entertainment system
device pins to the host connector plurality of entertainment device
pins. The assembly further comprises: USB repeater circuitry to
which the device connector plurality of USB pins and the host
connector plurality of USB pins are connected via connectors; and a
shell that encloses: at least a portion of the device connector; at
least a portion of the host connector; the direct connections; and
the USB repeater circuitry and its connectors.
DESCRIPTION OF THE DRAWINGS
[0013] The invention is described below with reference to the
drawings illustrating a preferred embodiment of the invention.
[0014] FIG. 1 is a block diagram illustrating the basic components
of a passenger entertainment system up to the seat electronics
box;
[0015] FIGS. 2A-C are pictorial views of an embodiment of the USB
repeater device;
[0016] FIG. 2D is a top view of the device shown in FIGS. 2A-C with
the top cover removed, exposing the circuit board;
[0017] FIGS. 3A, B are pictorial diagrams with line-outs of the
connectors on the USB repeater device;
[0018] FIGS. 4A, B are circuit diagrams showing line conditioning
and other circuitry of the USB repeater device;
[0019] FIG. 5 is a circuit diagram showing the lines going into an
actual USB repeater integrated circuit chip; and
[0020] FIG. 6 is a circuit diagram showing the current-limiting
circuitry for the USB repeater.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] According to various embodiments of the invention, the USB
repeater extends a range of connection between the personal control
unit (PCU) and the seat electronics box (SEB), which may span a
greater distance than the USB specification permits.
[0022] FIG. 1 is a block diagram illustrating a typical
configuration that might be used according to an embodiment of the
invention. A passenger entertainment system 220 typically comprises
an audio component 240 and a display 250 via which a passenger can
watch movies, play video games, obtain status information about the
flight, surroundings, listen to music, etc. The PCU 230 provides a
mechanism via which the user can control the audio 240 and display
250 components of the entertainment system 220.
[0023] In the prior art, signals from the PCU 230 (and other
components 240, 250) were directly connected by a cable to the SEB
200. However, since the desirability of using the USB standard for
communicating PCU information was recognized, and since a distance
between the PCU 230 and the SEB 200 might exceed the five-meter
limit imposed by the USB specification, a USB repeater 10 is
provided, having a cable 260 that connects the SEB 200 to the USB
repeater, and another cable 280 that connects the PCU 230 to the
USB repeater 10.
[0024] Although theoretically the PCU cable 280 could be provided
as a traditional USB connector cable, it is highly desirable to
group all cables associated with the passenger entertainment system
220 into a single cable 280. This permits easier routing, more
comprehensive shielding, and an easier diagnostic capability in
case of problems.
[0025] FIGS. 2A-2D illustrate an embodiment of the USB repeater 10.
As can be seen, this embodiment is created in a form factor similar
to D-backshell connector adapters. Accordingly, the repeater 10 has
a host (or SEB) connector 20 that is arranged as a DB-26 connector.
The host connector 20 may be fitted with spring latches 22 or with
sliding guides to ensure easy and reliable connection to the SEB
cable 260.
[0026] The repeater 10 also has a device connector 30 that connects
with the personal control unit cable 280 (which, in this
embodiment, comprises other signals associated with the
entertainment system 220). The device connector 30 can also be
arranged as a DB-26 connector. This connector could be used to
mount the repeater 10 to a wall or a frame element that holds the
repeater 10.
[0027] The repeater 10 comprises a top shell 40 and a bottom shell
42 that protects the internal components. In a preferred
embodiment, the shell 40, 42 is comprised of a conductive metal,
metalized plastic, or metalized composite, in order to electrically
shield the internal components from electrical interference. In one
embodiment, the shell 40, 42 is made of aluminum or an aluminum
alloy. The shell 40, 42 and components may further comprise
additional electrostatic discharge (ESD) elements such as
grounding, etc.
[0028] In a preferred embodiment, the dimensions of the main body
and connectors (without spring latches or attachment plates) for
the unit are approximately 7.6 cm..times.4.2 cm..times.1.75 cm.,
and do not exceed any one of these dimensions, and the unit has a
mass of approximately 36 g. This design thus satisfies the design
objectives of providing a small and lightweight device that is
hardened to conform with U.S. Aviation regulations.
[0029] FIG. 2D provides a top view of the repeater 10 with the top
shell 40 removed. Angled PCB pins 24, 34 are provided to connect
the host connector 20 and the device connector 30, respectively, to
the printed circuit board (PCB) 100. A USB repeater chip 110 is
provided on the PCB 100. Preferably the chip 110 is an
industrial-grade USB hub chip that is commercially available, such
as the SMSC's USB25/2I, the specification sheet herein incorporated
by reference--advantageously, this controller permits hot swapping
of the device.
[0030] ESD protectors 120 may also be provided on the PCB 100, such
as California Micro Devices CM1213-02SS, the specification being
herein incorporated by reference. Furthermore, current sense
circuitry 130 may be provided on the PCB 100, such as Maxim's
MAX1693EUB, the specification being herein incorporated by
reference. The ESD protectors 120 and current sense circuitry 130
are discussed in more detail below.
[0031] FIGS. 3A and 3B are pictorial diagrams of exemplary
connector pin-outs. FIG. 3A is an exemplary pin-out of the DB-26
device connector 30 going to the passenger entertainment system
220, and FIG. 3B is an exemplary pin-out of the DB-26 host
connector 20 going to the SEB 200. The repeater 10 simply passes
most of the signals from the passenger entertainment system 220 to
the SEB 200. However, the pins related to the PCU 230 are passed to
circuitry within the repeater 10 for further handling. On the host
connector 20, these include the PCU PWR J1-8 (and its associated
return PCU RTN J1-17), UP+ J1-9, and UP- (J1-18). On the device
connector 30, these include the PCU PWR OUT J1-8 (and its
associated return PCU RTN J1-17), DOWN+ J1-9, and DOWN-(J1-18).
[0032] FIGS. 4A and 4B provide various conditioning circuitry 102,
104 that can be used on the data and power lines. The data line
circuitry 102 can include electrostatic discharge protection
circuitry, such as California Micro Devices' CM1213 Low Capacitance
ESD protection arrays. The power line circuitry 104 can comprise
filter capacitors C3, C4, C7, C8 to help reduce noise. Note that
the shunt coils FB1, FB4 are optional and are not provided in a
preferred embodiment.
[0033] FIG. 5 provides an illustration of the signals going into
the USB repeater chip 110 itself, the chip U4 being, e.g., an SMC
USB2512/QFN36 chip. As can be seen, the UP+ and UP- signals from
the host connector 20 are provided to the USBUP_DP and USBUP_DM
(inverted) pins respectively. Also, the DOWN+ and DOWN- signals
from the device connector 30 are provided to the USBDN1_DP and
USBDN1_DM pins respectively. The VBUS_DET pin detects the state of
upstream VBUS power signaling a connect event. The OCS1 is an over
current sense signal that is an input from an external current
monitor indicating an over-current condition. This is connected
indirectly (through over current sense circuitry, illustrated in
FIG. 6) to the PRTPWR1 pin that enables power to USB peripheral
devices downstream.
[0034] FIG. 6 provides an illustration of the USB current limiting
and over-current sensing circuitry that may be employed. In a
preferred embodiment, a USB current limiting chip U3 is provided,
such as Maxim's MAX1693EUB, the specification sheet herein
incorporated by reference. The PCU OFF signal is provided to the
PRTPWR1 connector (FIG. 5). Although the over current sense
pursuant to the USB specification triggers at 500 mA, in a
preferred embodiment, the design of the current system is set to
trigger at 700 mA. Although in violation of the USB standard, this
permits more power to be available on the PCU and can account for
loss on the hub chip itself, cabling, etc.
[0035] The cable between the USB repeater 10 and the SEB 200 can be
a simple straight through cable, having DB-26 connectors on both
ends. The cable between the USB repeater 10 and the passenger
entertainment system 220 can be constructed as having a DB-26 on
one end, and a pigtail configuration on the other end, with each
end of the pigtail going to a separate device (e.g., PCU 230, audio
equipment 240, and display 250). All components used in the device
and cables are preferably industrial grade for purposes of
providing a robust and reliable connection.
[0036] For the purposes of promoting an understanding of the
principles of the invention, reference has been made to the
preferred embodiments illustrated in the drawings, and specific
language has been used to describe these embodiments. However, no
limitation of the scope of the invention is intended by this
specific language, and the invention should be construed to
encompass all embodiments that would normally occur to one of
ordinary skill in the art.
[0037] The present invention may be described in terms of
functional block components and various processing steps. Such
functional blocks may be realized by any number of components
configured to perform the specified functions. For example, the
present invention may employ various integrated circuit components,
logic elements, and the like, which may carry out a variety of
functions. Furthermore, the present invention could employ any
number of conventional techniques for electronics configuration,
signal processing and/or control, data processing and the like.
[0038] The particular implementations shown and described herein
are illustrative examples of the invention and are not intended to
otherwise limit the scope of the invention in any way. For the sake
of brevity, conventional electronics and other functional aspects
of the systems (and components of the individual operating
components of the systems) may not be described in detail.
Furthermore, the connecting lines, or connectors shown in the
various figures presented are intended to represent exemplary
functional relationships and/or physical or logical couplings
between the various elements. It should be noted that many
alternative or additional functional relationships, physical
connections or logical connections may be present in a practical
device. Moreover, no item or component is essential to the practice
of the invention unless the element is specifically described as
"essential" or "critical".
[0039] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural. Furthermore, recitation of ranges
of values herein are merely intended to serve as a shorthand method
of referring individually to each separate value falling within the
range, unless otherwise indicated herein, and each separate value
is incorporated into the specification as if it were individually
recited herein. Finally, the steps of all methods described herein
can be performed in any suitable order unless otherwise indicated
herein or otherwise clearly contradicted by context.
[0040] The words "mechanism" and "element" are intended to be used
generally and are not limited solely to mechanical embodiments.
Numerous modifications and adaptations will be readily apparent to
those skilled in this art without departing from the spirit and
scope of the present invention.
TABLE OF REFERENCE CHARACTERS
[0041] 10 USB repeater assembly [0042] 20 host connector [0043] 22
spring latches [0044] 24 host connector PCB pins [0045] 30 device
connector [0046] 34 device connector PCB pins [0047] 40 shell top
[0048] 42 shell bottom [0049] 100 PCB [0050] 102 USB data line
conditioning circuitry [0051] 104 USB power line conditioning
circuitry [0052] 110 USB repeater chip [0053] 120 ESD protectors
[0054] 130 current sense [0055] 200 seat electronics box (SEB)
[0056] 220 passenger entertainment system [0057] 230 personal
control unit (PCU) [0058] 240 passenger audio components [0059] 250
passenger display components [0060] 260 seat electronics box cable
[0061] 280 personal control unit cable
* * * * *