Digital Camera Patent Abstract
A connector, particularly suited for use in a digital camera, having
electrostatic discharge features that prevent the occurrence of
electrostatic discharge events. The connector comprises a printed
circuit board that includes a ground contact, a power contact, and
a plurality of signal contacts that are offset from an edge of the
printed circuit board. A row of vias are disposed between the signal
contacts and the edge of the printed circuit board, and adjacent
opposite sides of each of the signal contacts, that attract electrostatic
energy before it can reach the signal contacts. The signal contacts
have different lengths and shapes, depending upon their purpose.
An electrostatic discharge protection method and digital camera
are also disclosed. Digital Camera Patent Claims
What is claimed is:
1. A digital camera, comprising: a body; a circuit board; and an
edge connector comprising a ground contact, a power contact, and
a plurality of signal contacts disposed at predetermined distances
from an edge of the circuit board, and a row of vias disposed between
the signal contacts and the edge of the circuit board, and wherein
each respective edge connector signal contact has a via disposed
on either side thereof.
2. The digital camera recited in claim 1 wherein the ground contact
comprises a square tip that helps attract electrostatic discharge
signals.
3. The digital camera recited in claim 1 wherein the ground contact
is the longest contact to provide a ground connection before power
or signal contacts are contacted.
4. The digital camera recited in claim 3 wherein the power contact
is the next longest contact.
5. The digital camera recited in claim 4 wherein the power contact
applies power to the circuit board before any signal contact is
contacted.
6. The digital camera recited in claim 1 wherein the signal contacts
are furthest from the edge of the circuit board.
7. The digital camera recited in claim 1 wherein the shape of the
vias is elongated.
8. The digital camera recited in claim 1 wherein the vias are connected
to an electrostatic discharge reference voltage.
9. The digital camera recited in claim 1 wherein the vias are connected
to an electrostatic discharge reference voltage by way of a circuit
trace disposed on a different layer of the circuit board than the
signal contacts.
Digital Camera Patent Description
TECHNICAL FIELD
The present invention relates generally to electrical connectors,
and more specifically, to an edge connector having electrostatic
discharge arrest features and digital camera employing same.
BACKGROUND
The assignee of the present invention manufactures digital cameras,
and other computer-related devices. One current design of the assignee
of the present invention for a digital camera has a docking connector
on the bottom.
Since this docking edge connector needs to be used without a user
plugging something in (for example just setting the camera in its
base) the best type of connector is an edge connector. One problem
with this type of connection, is that it leaves the signals exposed.
This is undesirable from an electrostatic discharge (ESD) standpoint.
One solution is to protect these signals from electrostatic discharge
events with electronic devices, such as clamp diodes, capacitors,
or ferrite devices, and the like. However, this is a bad solution
from a cost and space standpoint. Furthermore, electrostatic discharge
(ESD) devices or doors on the product are expensive and requires
more space in the product.
U.S. Pat. No. 5,066,240 discloses "A high density electrical
connector comprised of a block of insulative material having a plurality
of electrical contacts for providing plural electrical connections
and an electrical conductor for providing electrostatic discharge
protection for the electrical contacts mounted thereto. The electrical
conductor is positioned forward of the electrical contacts relative
to the leading edge of the insulative material, thereby protecting
the electrical contacts from electrostatic discharges. In alternate
embodiments of the invention, the electrical connector may be a
plug type electrical connector with the electrical conductor mounted
on the leading edge of the projecting blades or may be a receptacle
type electrical connector with the electrical conductor mounted
to the leading edge of the insulative insert."
U.S. Pat. No. 6,079,620 discloses "A board adapter for electrically
transmitting signals between an electrical card connector and a
mother board, includes a plurality of signal traces formed on both
faces of the board adapter for electrically connecting signal holes
with corresponding conductive pads. The signal holes respectively
receive the corresponding contacts of the card connector. The conductive
pads electrically engage with corresponding contacts disposed within
a receiving slot defined in a card edge connector when the board
adapter is inserted therein and stabilizing means ensures proper
engagement therebetween. The stabilizing means comprises a cutout
defined on a bottom edge of the board adapter and a post formed
in the receiving slot of the card edge connector. The engagement
between the cutout and the post ensures that the conductive pads
of the board adapter are properly aligned with the contacts of the
card edge connector."
U.S. Pat. No. 5,319,523 discloses that "The main system printed
circuit board of a computer is mounted on a tray structure that
also supports other CPU components of the computer and is removably
insertable into the housing portion of the computer. A specially
designed card edge connector portion of the system board is operatively
insertable into a socketed connector on another circuit board interiorly
mounted within the housing. Electrically conductive signal fingers
and grounding fingers are respectively mounted on first and second
sides of the card edge, with the signal fingers being connected
to the signal plane of the system board, and the grounding fingers
being connected to its ground plane. A sacrificial grounding pad
is positioned on the second side of the edge connector portion,
between the grounding pads and its leading edge, and is initially
engaged by the internal connector contact strips, as the card edge
is being inserted into the connector, to equalize any voltage potential
between the two circuit boards before the contact strips engage
the signal and grounding fingers. The grounding pad thus eliminates
the necessity of incorporating clamping diodes in the system board
circuitry to avoid ESD damage to its components. The initially engageable
grounding pad also serves as a sacrificial contact wear member that
lengthens the connectivity life of the system board by diminishing
the mechanical wear-away of the signal and grounding fingers."
However, none of these patents disclose or suggest the use of signal
contacts are displaced inwardly away from the edge of the connector
that have different lengths and shapes, depending upon their purpose
and a row of vias in the connector that attract electrostatic energy
before it can reach the signal contacts.
What is desirable is a connector structure that prevents electrostatic
discharge events from ever reaching the signal pins. Accordingly,
it is an objective of the present invention to provide for an improved
docking edge connector that prevents electrostatic discharge from
occurring. It is also an objective of the present invention to provide
for digital camera employing the improved docking edge connector.
SUMMARY OF THE INVENTION
To accomplish the above and other objectives, the present invention
provides for a docking edge connector having electrostatic discharge
features that prevent the occurrence of electrostatic discharge
events. To prevent the occurrence of electrostatic discharge events,
the present invention provides a row of vias in the connector that
attract electrostatic energy before it can reach the signal contacts.
Furthermore, the signal contacts are displaced inwardly away from
the edge of the connector and have different lengths and shapes,
depending upon their purpose.
One advantage of the present invention over what has been done
before is that it is virtually cost free, eliminating the need for
discrete electrostatic discharge devices. The present invention
substantially reduces or eliminates electrostatic discharge problems
for exposed edge-connectors.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of embodiments of the present
invention may be more readily understood with reference to the following
detailed description taken in conjunction with the accompanying
drawings, wherein like reference numerals designate like structural
elements, and in which:
FIG. 1 illustrates an exemplary embodiment of a circuit board of
a digital camera having an edge connector in accordance with the
principles of the present invention;
FIG. 2 illustrates an exterior view of an exemplary embodiment
of a female portion of the present edge connector; and
FIG. 3 illustrates an exterior view of the exemplary embodiment
of the female portion of the edge connector shown in FIG. 2.
DETAILED DESCRIPTION
Referring to the sole drawing figures, FIG. 1 illustrates an exemplary
embodiment of a circuit board 10 of a digital camera 20. The digital
camera 20 comprises a body 21 (generally designated) in which the
circuit board 10 is housed. FIG. 2 illustrates an exterior view
of an exemplary embodiment of a female portion 30 of the edge connector
11. FIG. 3 illustrates an exterior view of the exemplary embodiment
of the female portion 30 of the edge connector 11 shown in FIG.
2.
The circuit board 10 comprises an edge connector 11 in accordance
with the principles of the present invention. A male portion 25
of the edge connector 11 is shown in FIG. 1. The male portion 25
of the edge connector 11 has a plurality of fingerlike contacts
12, 13, 14 including a ground contact 12, a power contact 13, and
a plurality of signal contacts 14.
Each of the finger contacts 12, 13, 14 are located at predetermined
distances from the outeredge 10a of the circuit board 10. The finger
contacts 12, 13, 14 are located at predetermined distances based
upon the signals that they receive. The ground contact 12 has a
square tip that helps attract the electrostatic discharge signals.
The ground contact 12 is also the longest contact to provide a ground
connection before power or signal contacts 13, 14 are contacted.
A slot 17 is provided at the edge 10a of the circuit board 10 that
is used to align the male portion 25 of the edge connector 11 in
the female portion 30 of the edge connector 11.
The power contact 13 is located on the right side of the ground
contact 12 and is the next longest contact. The power contact 13
applies power to the circuit board 10 before any signal contact
14 is contacted. The signal contacts 14 are the furthest from the
edge 10a of the circuit board 10.
Referring to FIGS. 2 and 3, the female portion 30 of the edge connector
11 comprises first and second offset circuit members 35a, 35b having
a plurality of connector wipers 31 that are coupled to a corresponding
plurality of conductive members 32. The plurality of conductive
members 32 reside in a corresponding plurality of slots 34 formed
in each of the offset circuit members 35a, 35b. A guide or registration
member 33 is sized to fit the slot 17 in the circuit board 10, to
register the male and female portions 25, 30 of the edge connector
11 when they are mated.
Referring again to FIG. 1, embodiments of the present invention
provide for a row of vias 15 that are disposed between the signal
contacts 14 and the outer edge 10a of the circuit board 10. Each
respective edge connector signal contact 14 has a via 15 disposed
on either side thereof. The vias 15 are disposed between the edge
connector signal contacts 14 so that connector wipers 31 (FIG. 3)
do not get damaged by the vias 15. The shape of the vias 15 is elongated
to provide better electrostatic discharge attraction. The vias 15
are connected to an electrostatic discharge reference voltage (ground,
for example) by way of a circuit trace 16 on a different layer of
the circuit board 10 than the signal contacts 14 since it is undesirable
for the wipers 31 to contact a trace.
A preferred embodiment of the present invention comprises a printed
circuit board 10 having the edge connector 11 disposed adjacent
to one edge thereof. The edge connector 11 comprises a plurality
of contacts 12, 13, 14 disposed adjacent to and separated from each
other that are offset from the edge of the printed circuit board
10.
In a preferred embodiment, the edge connector 11 comprises a plurality
of fingerlike contacts 12, 13, 14 including a ground contact 12,
a power contact 13, and a plurality of signal contacts 14. The ground
contact 12 has a square tip that helps attract electrostatic discharge
signals and is also the longest contact to provide a ground connection
before power or signal contacts 13, 14 are contacted. The power
contact 13 is the next longest contact and applies power to the
circuit board 10 before any signal contact 14 is contacted. The
signal contacts 14 are disposed the furthest distance from the edge
of the circuit board 10.
In the preferred embodiment, the row of vias 15 are disposed between
each signal contact 14 and are located between the outer edge of
the circuit board 10 and the plurality of signal contacts 14. The
vias 15 are disposed between the signal contacts 14 so that connector
wipers 31 do not get damaged by the vias 15. The shape of the vias
15 is elongated to provide better electrostatic discharge attraction.
The vias 15 are connected to an electrostatic discharge reference
voltage (ground, for example) by way of a circuit trace 16 on a
separate layer of the circuit board 10.
Thus, an edge connector having electrostatic discharge features
that prevent the occurrence of electrostatic discharge events, and
a digital camera employing same, have been disclosed. It is to be
understood that the above-described embodiments are merely illustrative
of some of the many specific embodiments that represent applications
of the principles of the present invention. Clearly, numerous and
other arrangements can be readily devised by those skilled in the
art without departing from the scope of the invention.
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