U.S. patent application number 09/835041 was filed with the patent office on 2001-11-29 for esd protective connector apparatus.
Invention is credited to Northway, David, O'Hara, Sean, Responte, Gary, Reynolds, Bruce, Tate, Joe.
Application Number | 20010046801 09/835041 |
Document ID | / |
Family ID | 24297080 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010046801 |
Kind Code |
A1 |
Tate, Joe ; et al. |
November 29, 2001 |
ESD protective connector apparatus
Abstract
Embodiments of the invention include connector assembly for a
handheld computer. The connector assembly includes a plurality of
conductive elements disposed on a first side of a printed circuit
board housed with the handheld computer. One or more of the
conductive elements has a pointed end.
Inventors: |
Tate, Joe; (San Jose,
CA) ; Reynolds, Bruce; (Gilroy, CA) ;
Northway, David; (San Carlos, CA) ; Responte,
Gary; (Fremont, CA) ; O'Hara, Sean; (Foster
City, CA) |
Correspondence
Address: |
WILSON SONSINI GOODRICH & ROSATI
650 PAGE MILL ROAD
PALO ALTO
CA
943041050
|
Family ID: |
24297080 |
Appl. No.: |
09/835041 |
Filed: |
April 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09835041 |
Apr 13, 2001 |
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09574664 |
May 18, 2000 |
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6241537 |
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Current U.S.
Class: |
439/181 ;
439/108; 439/81 |
Current CPC
Class: |
H01R 13/6485 20130101;
Y10S 439/951 20130101; H05K 1/026 20130101; H05K 2201/10189
20130101 |
Class at
Publication: |
439/181 ;
439/108; 439/81 |
International
Class: |
H01R 013/53; H01R
004/66; H01R 012/00; H05K 001/00; H01R 013/648 |
Claims
What is claimed is:
1. A connector assembly for a handheld computer, the connector
assembly comprising: a plurality of conductive elements disposed on
a first side of a printed circuit board housed with the handheld
computer, a first conductive element in the plurality of conductive
elements having a pointed end; a plurality of contacts, each of the
contacts contacting one of the plurality of conductive elements,
each contact including a first surface to mate with a connector
element of a first type of accessory connector, and a second
surface to mate with a connector element of a second type of
accessory connector; and a ground structure disposed on the printed
circuit board, the ground structure including a contour positioned
sufficiently proximate to the pointed end of the first conductive
element to form a spark gap, the spark gap transferring an
electrostatic discharge formed on one or more of the plurality of
conductive elements to the ground pad when the electrostatic
discharge exceeds a sufficient level.
2. The connector assembly of claim 1, where the first surface of
each contact mates with the connector element of a wiping style
connector on an accessory device.
3. The connector assembly of claim 2, wherein the second surface of
each contact mates with the connector element of a pogo style
connector on the accessory device.
4. The connector element of claim 1, wherein the first surface of
the contact is aligned to be acute or perpendicular to the second
surface of the contact.
5. The connector assembly of claim 1, further comprising at least
one vias associated with the first conductive element to transfer
electrostatic discharge from the pointed end of the first
conductive element to the ground pad.
6. The connector assembly of claim 1, wherein the grand pad
includes a plurality of interior sides that define an interior
space that at least partially surrounds the plurality of conductive
elements on three or more interior sides, at least one of the
interior sides having a saw tooth contour wherein at least a
portion of the saw tooth contour is positioned relative to the
point end of the first conductive element to define the spark
gap.
7. The connector assembly of claim 1, wherein the spark gap has a
length of about 0.20 mm to about 0.30 mm.
8. The connector assembly of claim 1, wherein the spark gap has a
gap distance of about 0.25 mm.
9. The connector assembly of claim 1, wherein the contour is
positioned sufficiently proximate to the pointed end to transfer
the electrostatic discharge exceeding 100 volts.
10. The connector assembly of claim 1, wherein the contour is
positioned sufficiently proximate to the pointed end to transfer
the electrostatic discharge exceeding t 100 volts but less than 250
volts.
11. The connector assembly of claim 1, wherein the point end of the
first conductive element is formed by at least two linear
sides.
12. The connector assembly of claim 11, wherein the pointed end of
the first conductive element has a triangular shape.
13. The connector assembly of claim 11, wherein the pointed end of
the first conductive element forms a rounded end.
14. The connector assembly of claim 1, wherein each of the
plurality of conductive elements are equidistantly spaced from one
another.
15. The connector assembly of claim 1, wherein the ground pad is
coupled to a charge storage device.
16. The connector assembly of claim 15, wherein the charge storage
device includes one of a electric battery or a capacitor.
17. A handheld computer comprising: a housing including a front and
back, the front of the housing providing access to a display; a
printed circuit board located in the housing, the printed circuit
board including a first side and a second side, the printed circuit
board interconnecting a plurality of internal components of the
handheld computer on the second side; a connector positioned to
mate with an accessory device, the connector including a plurality
of conductive elements positioned on the first side of the circuit
board to extend electrical communications to the accessory device,
a first conductive element in the plurality of conductive elements
including a pointed end; and a ground pad structure positioned
sufficiently proximate to the pointed end of the first conductive
element to enable an electrostatic discharge to be transferred from
the pointed end of the first conductive element when an
electrostatic discharge forms on one or more of the conductive
elements that is sufficient to cross the spark gap.
18. The handheld computer of claim 17, wherein the ground pad
structure includes a contour that extends towards the pointed end
of the first conductive element to form the spark gap.
19. The handheld computer of claim 17, wherein the ground pad
structure includes at least three interior sides that define an
interior space that substantially surrounds the plurality of
conductive pads on three or more interior sides, at least one of
the interior sides having a saw tooth contour wherein at least a
portion of the saw tooth contour is positioned relative to the
pointed end of the first conductive element to define the spark
gap.
20. The handheld computer of claim 17, further comprising a vias
extending between the first and second side of the circuit board to
electrically interconnect one or more of the plurality of
conductive elements with one or more of the plurality of internal
components on the second side of the circuit board.
21. The apparatus of claim 17, wherein the contour of the ground
pad includes a pointed tooth spaced from the pointed end of one of
the conductive elements to define the spark garp.
22. The apparatus of claim 17, wherein the spark gap structure is
configured to initiate a current flow between at least of one the
plurality of the conductive elements and the ground pad structure
when a electrical potential between the at least one of the
conductive elements and the ground pad structure exceeds a
threshold level.
23. A handheld computer comprising: a housing including a front and
a back, the front of the housing providing access to a display; a
connector accessible to interconnect with a mating connector of an
accessory device; and an electrostatic discharge feature configured
to dissipate an electrostatic charge having a voltage exceeding a
threshold level upon the connector being mated with the mating
connector of the accessory device.
24. The handheld computer of claim 23, further comprising a door,
the door being slideable between a door including a closed position
and an open position, the connector being accessible when the door
is in the open position.
25. The handheld computer of claim 24, wherein the door is biased
to remain in the closed position until a force directs the door to
the open position.
26. The handheld computer of claim 23, wherein the electrostatic
discharge feature includes a pointed end positioned on each of a
plurality of conductive elements disposed on a circuit board of the
handheld computer.
27. The handheld computer of claim 26, wherein the electrostatic
discharge feature includes a ground pad positioned sufficiently
proximate to the pointed ends of the conductive elements to form a
spark gap to transfer an electrostatic discharge from the
conductive elements to the ground pad.
28. The handheld computer of claim 27, wherein the electrostatic
discharge feature includes a plurality of contours on the ground
pad, each of the contours being positioned proximate to a
corresponding conductive element of the plurality of conductive
elements.
29. The handheld computer of claim 28, wherein the electrostatic
discharge feature includes a plurality of saw-tooth contours on the
ground pad.
30. The handheld computer of claim 26, wherein the electrostatic
discharge feature includes a ground pad including a tooth spaced
from each pointed end to form the electrostatic discharge
features.
31. The handheld computer of claim 23, further comprising: a
plurality of contacts, each of the contacts contacting one of the
plurality of conductive elements, each contact including a first
surface to mate with a connector element of a first type of
accessory connector, and a second surface to mate with a connector
element of a second type of accessory connector.
32. The handheld computer of claim 31, wherein the first surface
mates with the connector element of a wiping style connector, and
the second surface mates with the connector element of a pogo style
connector.
33. An accessory device for a handheld computer comprising: a stand
for placement of the handheld computer; a mating connector to mate
with another connector of a handheld computer when the handheld
computer is rested on the stand; an outlet to communicate with
another computer; and an electrostatic discharge feature configured
to dissipate an electrostatic charge having a voltage exceeding a
threshold level upon the mating connector being mated with the
other connector of the handheld computer.
34. A handheld computer comprising: a housing including a first and
a back, the front of the housing providing access to a display; a
connector including a plurality of contacts, each contact including
a first surface to receive an element wiping style connector, and a
second surface to receive an element of a pogo style connector; a
ground pad positioned adjacent to the connector; and means for
transferring an electrostatic discharge forming on the connector to
the ground pad.
35. A handheld computer comprising: a housing including a first and
a back, the front of the housing providing access to a display; a
connector accessible to interconnect with a mating connector of an
accessory device; a door including an open position to provide
access to the connector and a closed position to protect the
connector; a ground pad positioned adjacent to the connector; and
means for transferring an electrostatic discharge forming on the
connector to the ground pad.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention pertains to handheld computers and accessory
devices for handheld computers. More specifically, embodiments of
this invention encompass a handheld computer with an ESD protective
connector.
[0003] 2. Description of the Related Art
[0004] Handheld computers use peripheral or accessory devices to
enhance their abilities and functions. Typical accessory devices
for handheld computers include communication cradles or docking
stations, battery chargers, Universal Serial Bus (USB) devices, and
modems. Generally, these devices are adapted to mate with the
handheld computer using either wiping style connectors or pogo
style connectors.
[0005] Until now, handheld computers were adapted to connect with
accessory devices having either a wiping style or a pogo pin
connector. During or after the mating process with either
connector, a static electric discharge or electrostatic discharge
event (EDE) can occur that can damage electronic components in the
handheld computer. The static electric discharge occurs due to the
buildup of static electricity on the accessory device, the user or
the handheld computer. The voltages that drive an electrostatic
discharge can be significant. In fact, when the humidity drops
below 50% Rh, the human body can acquire and dissipate an
electrostatic charge having a potential in excess of 30,000 volts.
Unfortunately, many devices are susceptible to ESD damage at
relatively low voltages e.g. less than 100 Volts. In fact, a
discharge of only 10 Volts can destroy some types of devices.
[0006] The microelectronics of a handheld computer are particularly
sensitive to damage from electrostatic discharge or ESD. This due
to fact that these components are composed of micro-miniature
traces and structures of alternating layers that may be insulative,
conductive or semi-conductive. Rapid electrostatic discharge can
cause damage to these underlying structures via the traces of the
component. Thus static electricity can readily damage integrated
circuits containing such traces including, microprocessors, ASICS
and memory devices including RAM and ROM devices. The damage can
range from erasure of memory registers and contents to physical
damage of the circuits due to damage of the traces.
[0007] Handheld computers are also susceptible to such discharges.
For example, when the interface connector of the handheld computer
is unmated, the electronic components that are connected to this
unmated connector are susceptible to receiving, through the
conductive pins of the unmated connector, an electrostatic
discharge current from an electrostatically charged human or other
sources of an electrostatic charge. Similarly, during or after the
mating process of the connector to accessory device, electrostatic
current can flow from the accessory device the hand-held computer,
causing damage to internal components of the handheld computer.
SUMMARY OF THE INVENTION
[0008] An embodiment of the invention includes a handheld computer
including electrostatic discharge feature. The electrostatic
discharge feature is configured on the connector of the handheld
computer to dissipate an electrostatic charge having a voltage
exceeding a threshold level upon the connector being made with
another connector of an accessory device. Examples of an accessory
device include communication cradles for use with handheld
computers.
[0009] Among other advantages, embodiments of the invention provide
a versatile connector with a current path to dissipate charge
delivered by an ESD event. This feature includes potential damage
from ESD events particularly during and connection and
de-connection to an accessory device. Further, embodiments of the
invention improve reliability in making and maintaining an
electrical connection between the handheld computer and accessory
device. Additionally, the current associated with an ESD event and
its derivative are reduced, minimizing damage such as latchups,
register erasure, data loss and physical damage.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1 illustrates a handheld computer for use with an
embodiment of this invention.
[0011] FIG. 2A is a back view of the handheld computer, showing
details of a connector for use with an embodiment of this
invention.
[0012] FIG. 2B illustrates a single contact element for the
connector shown in FIG. 2A.
[0013] FIG. 2C is a back view of a handheld computer, including a
door to cover a connector, for use with an embodiment of the
invention.
[0014] FIG. 3A illustrates a pogo connector for use with an
embodiment of this invention.
[0015] FIG. 3B illustrates a handheld computer mated with a
communication cradle, under an embodiment of the invention.
[0016] FIG. 4 is a side view illustrating handheld computer mated
with a cradle, under an embodiment of the invention.
[0017] FIG. 5A is a top view showing a printed circuit board
including an electrostatic discharge feature, under an embodiment
of the invention.
[0018] FIG. 5B illustrates the printed circuit board in an
embodiment where a ground pad structure partially surrounds
conductive elements on the printed circuit board, the conductive
elements electrostatic discharge features, under an embodiment of
the invention.
[0019] FIG. 5C is a close-up of a conductive element and a ground
pad structure forming a spark gap on the printed circuit board,
under an embodiment of the invention.
[0020] FIG. 5D is a close-up of a conductive element and the ground
pad structure forming two spark gaps, under an embodiment of the
invention.
DETAILED DESCRIPTION
[0021] Embodiments of this invention provide a versatile connector
having electrostatic discharge protection capabilities for use with
portable computers, and in particular, handheld computers. Such
embodiments provide protection of various electronic components
located inside the handheld computer, including components coupled
to printed circuit boards within the handheld computer.
[0022] A. Overview
[0023] A connector for use with a handheld computer includes one or
conductive elements or pads. Under embodiments of the invention,
the conductive elements are at least partially surrounded by one or
more spark gap structures that are each configured to discharge to
a dissipative pad or ground pad.
[0024] The spark gap is configured so that when a threshold
electrical potential is exceeded, as would occur during an
electrostatic discharge event, current flows across the spark gap
from conductive elements of the connector to ground. The
electrostatic event may occur when the handheld computer is
connected than accessory device, such as a communication cradle. As
a result, embodiments of the invention provide a protective pathway
to ground for an electrostatic discharge current that might
otherwise damage electronic components of the handheld
computer.
[0025] In various embodiments the ground pad can be coupled to the
handheld computer battery, capacitor or other energy storage
device. These devices can be integral to or otherwise
electronically coupled to the ground pad.
[0026] While embodiments described herein are described for
handheld computers, other embodiments may be applicable in other
types of computer devices. For example, embodiments of the
invention may be incorporated into personal computers, lap tops and
cell phones. In addition, the electrostatic discharge feature can
be integrated into an accessory device for a handheld computer.
Examples of accessory devices include communication cradles.
[0027] In an embodiment, a connector is formed from a combination
of conductive elements or leads formed on a circuit board. One or
more of the conductive elements are provided an electrostatic
discharge feature, formed from a geometry of the conductive
elements and a spark gap with a ground pad structure. The
conductive elements extend communications to the electrical
components of the handheld computer. One or more vias may be used
to connect the conductive elements on one side of the printed
circuit board to electrical components on another side of the
printed circuit board.
[0028] In an embodiment, a handheld computer incorporates a dual
style connector with an electrostatic discharge feature. The
electrostatic discharge feature may be integrated into the printed
circuit board. The dual-style connector may be formed as an
extension off of the PCB. The dual-style connector enables the
handheld computer to mate with multiple types of accessory devices,
including wiping style connectors and pogo style connectors. An
example of a dual style connector is provided by U.S. patent
application Ser. No. 09/313,333, herein incorporated by
reference.
[0029] In another embodiment, a housing of the handheld computer
includes a sliding door. The sliding door opens to provide access
to a PCB connector, including an electrostatic discharge feature.
An example of such a slide sliding door is provided by U.S. patent
application Ser. No. 09/037,195, herein incorporated by
reference.
[0030] B. PCB Connector with Electrostatic Discharge Feature
[0031] FIGS. 5A illustrates a printed circuit board (PCB) 520
retained within a housing 110 (FIG. 1) of a handheld computer 100
(FIG. 1). FIG. 5A shows a back side 521 of the PCB 520 facing a
back face 112 (FIG. 2) of handheld computer 100. In the embodiment
shown, back side 521 includes a PCB connector 500 having an ESD
protection feature. A front side (not shown) of the PCB 520
interconnects and retains electrical components (not shown) for
handheld computer 100. Examples of electrical components provided
on the front side of the PCB 520, include a processor, voltatile
memory, non-voltatime memory, and an analog-digital converter.
[0032] The PCB connector 500 mates with another device to extend
communications to and from handheld computer 100. In one
embodiment, PCB connector 500 mates with a connector of a docking
port. For description herein, PCB 520 is referenced against a
top-down configuration so that a top of the PCB coincides with a
portion where display 114 (FIG. 1) of handheld computer 100 is made
accessible. A bottom portion of PCB 520 includes PCB connector
500.
[0033] The PCB connector 500 includes a plurality of conductive
elements 555. On PCB 520, the conductive elements 555 are spaced or
gapped from a ground pad structure 550. A gap 570 (FIG. 5C and 5D)
between the conductive elements 555 and ground pad structure 550
enables an electrostatic discharge when an electrostatic voltage or
current exceeds a threshold or breakdown level.
[0034] In the embodiment shown by FIG. SA, PCB connector 500 is
disposed a distance away from a bottom edge 523 of PCB 520. The
ground pad structure 550 completely surrounds PCB connector 500, so
that conductive elements 555 are separated from the bottom edge 523
of the PCB 520 by ground pad structure 550.
[0035] The pattern and number of conductive elements 555 may be
configured for both serial and parallel data connections. In an
embodiment, PCB connector 500 includes nine conductive elements 555
evenly spaced from one another. The nine conductive elements 555
provide eight bits of data and a parity bit.
[0036] One or more vias 560 (FIG. 5C) may be provided to extend
electrical contact from the conductive elements 555 to the
electrical components on the front side (not shown) of PCB 520. The
vias 560 may be formed in any location or area in contact element
555.
[0037] FIG. 5B illustrates PCB 520, under another embodiment of the
invention. The PCB 520 positions ground pad structure 550 to
partially surround the plurality of contact elements 555. The
ground pad structure 550 extend between the bottom edge of PCB 520
and the conductive elements 555. This formation allows conductive
elements 555 of PCB connector 500 to be positioned closer to bottom
edge 523, when compared to embodiments such as described with FIG.
SA. The positioning of PCB connector 500 on PCB 520 allows handheld
computer 100 to mate with other devices at different angles or
positions, and may also affect the type of connectors that can mate
with handheld computer 100. Further, positioning the PCB connector
500 closer to the bottom edge 523 facilitates use of a sliding door
structure 280 (FIG. 4) as will be described.
[0038] FIG. 5C illustrates conductive element 555 and ground pad
structure 550 in greater detail, under an embodiment of the
invention. The conductive-element 555 is oriented lengthwise within
a space surrounded by ground pad structure 550. The contact element
555 includes a pointed portion, shown in FIGS. 5A-5D as pointed end
552. One or more of contact elements 555 includes vias 560 to
extend an electrical connection to components on the front side of
the PCB 520. With reference to FIG. SC, vias 560 extends into the
paper to electrical components and circuitry on the other side of
PCB 520.
[0039] The pointed end 552 is a portion of the conductive element
555 that is proximate to ground pad structure 550. The pointed end
552 is formed by a segment that narrows with proximity to ground
pad structure 550. In an embodiment, the pointed end 552 forms a
distal tip along the lengthwise axis of the contact element.
[0040] As shown, the pointed end 552 is formed by two peripheral
edges 553 that form an angle. The angle between peripheral edges
553 is preferably ninety degrees. In other embodiments, the pointed
end 552 may include a contour to form a rounded tip, rather than a
tip formed by two linear edges.
[0041] The ground pad structure 550 includes a toothed portion 522
that is proximate to the pointed end 552 of conductive element 555.
In an embodiment, toothed portion 522 is also pointed and includes
a tip 523 that is proximate to pointed end 552. The pointed end 552
of conductive element 555 is positioned a selectable distance from
tip 523 of toothed portion 522. The distance between the pointed
end 552 and tip 523 defines spark gap 570. The proximate
relationship between pointed end 552 and ground pad structure 550
provides an electrostatic discharge feature for PCB connector
500.
[0042] In an embodiment, each conductive element 555 includes a
pointed end 552 that is proximate to a corresponding toothed
portion 522 of ground pad structure 550. Collectively, the
electrostatic discharge features provided by each of the conductive
elements 555 enable an electrostatic charge to discharge from one
or more conductive elements 555 to ground pad 550. Thus, the
electrostatic discharge feature produces point discharge to channel
or otherwise bias electrostatic charge from conductive elements 555
across spark gap 570 to ground pad 550. Sufficient static build-up
may exceed a breakdown voltage causing static charge to spark
across spark gap 570. The break down voltage is significantly less
than the voltage required to produce a spark between adjacent
conductive conductive elements 555 on PCB connector 500. In this
way, spark gap 570 and ground pad structure 550 provide a low
impedance discharge path for electrostatic charges to safely
discharge to ground rather than to a sensitive components of
handheld computer 100.
[0043] One factor affecting the threshold level or breakdown
voltage is the distance of spark gap 570. In general, a larger
spark gap 570 requires a larger break down voltage to cause an
electrostatic spark to occur. Preferably, the spark gap 570 is
measured so that the breakdown voltage across the spark gap is
substantially less than breakdown voltage between adjacent
conductive elements 555. Further, spark gap 570 is measured so that
the breakdown voltage across the spark gap 570 is less than the
breakdown voltage between conductive elements 555 and circuitry, or
components near or at connector 550, including conductive traces or
circuits.
[0044] The spark gap 570 is selected to achieve a desired breakdown
voltage resulting from an ESD event. In an embodiment, spark gap
570 is in the range of 0.1 to 0.4 mm, and preferably between 0.2 to
0.3 mm. In one specific embodiment, the dimension of the spark gap
570 are 0.25 mm. In these embodiments, the breakdown voltage ranges
from 50 to 500 volts, with a preferred range of 100 to 250 volts.
Several design factors and parameters can affect the minimum
breakdown voltage across spark gap 570. These include the shape of
pointed end 553, the shape of toothed portion 522, and the relative
proximity between the pointed end 552 and the toothed end. Other
factors include electrical properties of the conductive elements
555 and ground pad structure 550, as well as the number of spark
gaps 570 included in PCB connector 500. The exact threshold level
may also be affected on factors such as environmental conditions,
including temperature and humidity.
[0045] Ground pad 550 can be fabricated from electrostatic
electrostatic dissipative materials. Examples of such materials
include metals such as gold and copper, as well as semi-conductive
materials.
[0046] FIG. 5D illustrates another embodiment in which conductive
element 555 is shaped so as to include a second pointed end 562.
The second pointed end 562 is positioned length-wise across from
pointed end 552. In this embodiment, ground pad structure 550 is
assumed to surround PCB connector 500 on all sides, and separates
PCB connector 500 from the bottom edge 523. The ground pad
structure 550 includes a plurality of second toothed portion 532.
The second toothed portion may also be pointed to include tip 533.
Each of the second toothed portions 532 are aligned to form a spark
gap 580 with each of the second pointed ends 580, respectively. In
this way, each PCB connector 500 includes at least two possible
electrostatic dissipitative paths along both directions defined by
the length-wise axis.
[0047] The use of multiple sparks gaps 570, 580 for each connector
elements provides the benefit of a higher degree of reliability of
ESD protection by assuring ESD current going in any connector
element 555 will have a direct low impedance path to ground pad
520, thereby reducing the risk of arcing to adjacent elements.
Further, the use of multiple spark gaps 570, 580 for each
conductive element 555 (as shown in FIG. 5A) further improves the
reliability of ESD protection by reducing the conductive pathway
distance to the ground pad and hence the impedance between each
connector element 555 and the ground pad 550.
[0048] In an embodiment, the breakdown levels for each spark gap
570, 580 of the conductive elements 555 may be different, or the
same. Further, one or more of the conductive elements 555 may be
positioned outer contact elements that extend lengthwise next to
the ground pad structure 550. In FIG. 5A, the far left and far
right conductive elements 555 correspond to outer contact elements.
The outer contact elements may be positioned lengthwise to be
adjacent the ground pad structure 550 in a lengthwise orientation,
so that the distance between the length of that conductive element
555 and ground pad structure 550 also forms a spark gap.
[0049] With reference to FIGS. SC and 5D, one or more of the
conductive elements 555 include a vias 560. The vias 560 extend
electrical contact from the conductive elements 555 to components
on the other side of PCB 520. The electrostatic discharge feature
of each conductive element 555 prevents the vias 560 from carrying
damaging charges to the components on the front side of PCB
520.
[0050] The ground pad 520 can be shaped or positioned as a pad, or
as one or more ground traces. In addition, ground pad structure 550
may include one or more vias that extend to additional ground
structures on the front side of PCB 520.
[0051] In other embodiments, ground pad 550 is conductively coupled
to an electrical storage battery, a capacitor, or other energy or
charge storage devices so as to better dissipate the ESD charge.
Alternatively, the battery itself can comprise the ground pad 550,
or the ground pad 550 can be integral to the battery.
[0052] Incorporating the spark gap 570 as an electrostatic
dissipitative feature of handheld computer 100 provides multiple
benefits and improvements over prior connector designs. The
benefits include providing protection against ESD damage to all
electrical components and circuits on the handheld computer 100.
These components include the processor memory, circuitry, and other
internal components of the handheld computer 100 from static
electric discharges.
[0053] In practice, embodiments of the ESD protective PCB connector
500 provide ESD protection to handheld computer 100 in multiple
scenarios involving electrostatic discharge. These scenarios
include discharges from the accessory device to the handheld
computer via the connector of either device or other route, before
during or after the connection of the hand-held computer to the
accessory device. The ESD protective scenarios also include
discharges from the user to the hand-held computer directly or
indirectly (e.g. through the accessory device or other electronic
device). This is due to the fact that an ESD current from a user
will be most likely to enter through the PCB connector 500 (the
path of lowest impedance) where it will be channeled/biased to flow
across spark gap 570 and into the ground pad 520 where it will be
safely dissipated.
[0054] FIG. 1 depict a handheld computer 100 that may incorporate
an electrostatic discharge feature, as described in embodiments of
the invention. The handheld computer 100 has an internal power
source (not shown), such as a rechargeable battery. The handheld
computer 100 may operate one or more application programs, such as
electronic calendar, memos, phone lists, calculators, and emails.
The handheld computer 100 may also include an operating system.
[0055] Examples of handheld computer 100 include palm style
computers such as a PalmPilot.TM., Palm III.TM., Palm V.TM. and
Palm VII.TM. organizers, manufactured by the Palm, Inc. Other
examples include Handspring Visor.TM. and TRG PRO.TM. devices.
Other embodiments of the invention can include handheld computers
operating Windows CE.TM. operating system. Handheld computers may
also include wireless enabled devices, such as BlueTooth enabled RF
devices, cell phones, and Sprint PCS.TM. phones.
[0056] A housing 110 of handheld computer 100 includes a top and
bottom edge 102, 104, and a pair of opposing lateral sides 105. A
front face 111 of the handheld computer 100 includes a plurality of
input functions keys 115 and a display 114 having graphical user
interface features. The input function keys 115 and display 114 may
provide data entry. For example, display 114 may be used to enter
data into a calendar application operating on handheld computer
100.
[0057] In an embodiment, handheld computer 100 communicates with
other computer systems through one or more communication ports.
Examples of other computer systems include networks such as the
Internet, or desktop computers. Examples of communication ports
include infra-red (IR) ports (not shown), radio frequency ports,
and serial data ports. In an embodiment, connector 150 may be used
as a serial data port.
[0058] FIG. 2A illustrates a back face 112 of handheld computer 100
that includes a dual style connector 250. In an embodiment, dual
connector 250 is an extension of PCB connector 500. The dual
connector 250 is used to communicate with other accessory devices
that extend functionality of the handheld computer 100. The dual
connector 250 may be located at or near bottom edge 104 of housing
110. The position of connector 250 facilitates mating handheld
computer 100 with accessory devices.
[0059] The dual connector 250 includes a plurality of contact
elements 260 contained in an insulative body 255. The combination
of contact elements 260 and insulative body 255 may be mounted or
otherwise positioned adjacent to the backside 521 of PCB 520 (FIGS.
5A-5D), so that the contact elements 260 are each in electrical
contact with a corresponding conductive element 555 on PCB 520
(FIGS. 5A-5d). The insulative body 255 provides insulative material
between the individual contact elements 260. In an embodiment, a
plurality of extensions 215 are spaced apart to insulate individual
contact elements 260 located between adjacent pairs of
extensions.
[0060] The dual connector 250 is adapted to mate with different
types of accessory connectors. In an embodiment, dual connector 250
is matable with either a pogo-style connector or a wiping style
connector. Each of the contact elements 260 include a horizontal
contact dimension for mating with the wiping style connector and a
vertical contact dimension for mating with the pogo-style
connector. Dual connector 250 may be mounted with PCB 520 to enable
handheld computer 100 to mate with an accessory device having
either the wiping style or pogo style connector.
[0061] FIGS. 2B is an illustrative side view of FIG. 2A. The
contact element 260 of dual connector 250 in contact with one of
the leads 555 of PCB connector 500. As shown, a vertical dimension
262 of contact element 260 receives pogo-style connector 410. A
horizontal dimension 264, shown in FIG. 3A as being relatively
planar with PCB 520, receives wiping style connector 420. FIG. 3A
illustrates only one contact element 260 of dual connector 250, in
contact with one lead 555 of PCB connector 500. Other elements of
dual connector 250 may individually contact leads 555 of PCB
connector 500 in the same manner.
[0062] The contact element 260 is a portion of a structure that
includes other contact elements 260 and insulative body 255. The
structure may be mounted so that the vertical dimension 262 of the
contact element 260 is in contact with conductive element 555 of
PCB connector 500. For example, the structure may be integrated as
part of the housing, and dimensioned so that the vertical dimension
262 (or other components) is in contact with the conductive element
555.
[0063] In other embodiments, PCB connector 500 may mate directly
with connectors of other accessory devices. In particular, PCB
connector 500 may mate with wiping style connectors. For example,
PCB connector 500 may mate with communication cradle 400.
[0064] FIG. 2C illustrates a back face 275 of handheld computer
100, that includes a sliding door structure 280, under an
embodiment of the invention The sliding door structure 280 houses
PCB connector 500 (FIGS. 5A-5B). The sliding door structure 280 is
moveable between an open and closed position. In the open position,
the sliding door structure 280 is biased to move into the closed
position by a spring (not shown). PCB connector 500 is positioned
on PCB 520 so as to mate with a wiping style connector of an
accessory device.
[0065] FIG. 3A illustrates a pogo style connector 300 of an
accessory device that is matable with handheld computer 100. The
pogo connector 300 includes a plurality of connector elements 310,
each of which may be shaped as circular shaped extensions. Each
connector element 310 of the pogo style connector 300 is
spring-biased when moved inwards. The pogo style connector may be
used to make accessory devices such as battery charges to the
handheld computer.
[0066] FIG. 3B illustrates a cradle 410 including a base 415 that
rests on a platform or floor. The communication cradle 410 includes
a mating connector 450 to connect with PCB connector 500. The
cradle 410 includes a tilted front face 420 that merges into a
ledge 430. The ledge 430 supports handheld computer 100. In this
way, handheld computer 100 is rested on the ledge 430 to cause PCB
connector 500 to mate with connector 450. The tilt of the front
face 420 combined with the support of the ledge 430 serves to
retain the handheld computer 100 on the cradle 400.
[0067] The mating connector 450 includes a plurality of connector
elements 455. In another embodiment, one or more of the plurality
of connector elements 455 may include an electrostatic discharge
feature, such as described with embodiments of handheld computer
100.
[0068] FIG. 4 illustrates handheld computer 100 mated with
communication cradle 410, under an embodiment where handheld
computer 100 includes sliding door structure 280. When handheld
computer 100 is mated with communication cradle 410, sliding door
280 is moved into the open position. In an embodiment, sliding door
280 is positioned to be pushed into the open position by structure
465 of connector 450 on communication cradle 410. In the open
position, PCB 520 and PCB connector 500 are exposed to mating
connector 450. In the embodiment shown, contact element 455 of
connector 450 is a wiping style element. The sliding door structure
280 may be moved into the open position by resting handheld
computer 100 on communication cradle 410. The position of PCB
connector 500 and sliding door structure 280 relative to a
connector structure 415 (FIG. 4A) on the communication cradle 410
enables handheld computer 100 to mate with communication cradle
420.
[0069] The foregoing description of various embodiments of the
invention has been presented for purposes of illustration and
description. It is not intended to limit the 5 invention to the
precise forms disclosed. Obviously, many modifications, variations
and different combinations of embodiments will be apparent to
practitioners skilled in the art. Also, it will be apparent to the
skilled practitioner that elements from one embodiment can be
readily recombined with one or more other embodiments.
[0070] In an alternative embodiment, an accessory device for
handheld computer 100 includes the electrostatic discharge feature.
For example, one or more connector elements on communication cradle
410 include a pointed end spaced from a ground, thereby forming a
spark gap.
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