U.S. patent application number 10/047600 was filed with the patent office on 2003-04-24 for anti-abrasive flat flexible cable.
Invention is credited to Hung, Wen-Lung, Sheng, Kung-Cho.
Application Number | 20030075353 10/047600 |
Document ID | / |
Family ID | 21679535 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030075353 |
Kind Code |
A1 |
Sheng, Kung-Cho ; et
al. |
April 24, 2003 |
ANTI-ABRASIVE FLAT FLEXIBLE CABLE
Abstract
An anti-abrasive flat flexible cable for use with an image
scanner for electrically connecting a carriage with a circuit board
is disclosed. The flat flexible cable includes a metal foil having
a first end electrically connected to the circuit board and a
second end electrically connected to the carriage for signal
transmission between the circuit board and carriage; a
thermoplastic plastic wrapper enclosing the metal foil with two
opposite ends of the metal foil exposed for electric connection
with the circuit board and the carriage, respectively; and a spacer
strip selected from a group consisting of Teflon, Nylon and
polyoxylated methylene (POM), and attached onto the thermoplastic
plastic wrapper for isolating the thermoplastic plastic wrapper
from the glass scanning platform.
Inventors: |
Sheng, Kung-Cho; (Taipei,
TW) ; Hung, Wen-Lung; (Taipei, TW) |
Correspondence
Address: |
MADSON & METCALF
GATEWAY TOWER WEST
SUITE 900
15 WEST SOUTH TEMPLE
SALT LAKE CITY
UT
84101
|
Family ID: |
21679535 |
Appl. No.: |
10/047600 |
Filed: |
January 14, 2002 |
Current U.S.
Class: |
174/117F |
Current CPC
Class: |
H04N 1/0083 20130101;
H05K 3/28 20130101; H04N 1/1013 20130101; H05K 1/0393 20130101;
H02G 11/006 20130101 |
Class at
Publication: |
174/117.00F |
International
Class: |
H01B 007/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2001 |
TW |
090125858 |
Claims
What is claimed is:
1. An anti-abrasive flat flexible cable for use with an image
scanner for electrically connecting a carriage with a circuit
board, said flat flexible cable being bent at different positions
thereof with the movement of said carriage relative to said circuit
board under a scanning platform, and comprising: a flexible
conductive portion having a first end electrically connected to
said circuit board and a second end electrically connected to said
carriage for signal transmission between said circuit board and
carriage; a flexible insulating portion wrapping around said
flexible conductive portion for protecting said flexible conductive
portion; and a flexible spacer portion attached onto said flexible
insulating portion, and positioned between said flexible insulating
portion and said scanning platform for isolating said flexible
insulating portion from said scanning platform.
2. The anti-abrasive flat flexible cable according to claim 1
wherein said flexible conductive portion includes a copper
foil.
3. The anti-abrasive flat flexible cable according to claim 1
wherein said flexible insulating portion is made of a thermoplastic
plastic material.
4. The anti-abrasive flat flexible cable according to claim 1
wherein a hardness of said flexible spacer portion and a fictional
coefficient between said flexible spacer portion and said scanning
platform are small enough to substantially render no chip on
contact.
5. The anti-abrasive flat flexible cable according to claim 4
wherein said scanning platform is made of glass, and said flexible
spacer portion is made of a material selected from a group
consisting of Teflon, Nylon and polyoxylated methylene (POM).
6. The anti-abrasive flat flexible cable according to claim 4
wherein said scanning platform is made of glass, and said flexible
spacer portion is made of a composite material including Nylon and
POM.
7. The anti-abrasive flat flexible cable according to claim 1
further comprising a rigid supporting plate mounted to each of said
first and second ends of said flexible conductive portion for
facilitating the exertion of an external force to insert said
flexible conductive portion to a slot of said circuit board or said
carriage.
8. The anti-abrasive flat flexible cable according to claim 7
wherein said flexible spacer portion is disposed between said rigid
supporting plate and said flexible conductive portion, and extends
along said flexible insulating portion over a half length of said
flexible insulating portion.
9. An anti-abrasive flat flexible cable used in a housing for
signal transmission between a first and a second devices, and
comprising: a flexible conducting core for conducting an electronic
signal; and a flexible insulating wrapper enclosing said flexible
conductive core for protecting said flexible conductive core with
two opposite ends of said flexible conductive core exposed for
electric connection to said first and second devices, respectively,
wherein said flexible insulating wrapper includes a spacer portion
possibly in contact with said housing, and a hardness of said
spacer portion and a frictional coefficient between said spacer
portion and said housing are small enough to substantially render
no chip on contact.
10. The anti-abrasive flat flexible cable according to claim 9
wherein said flexible conductive core is formed of a copper
foil.
11. The anti-abrasive flat flexible cable according to claim 9
wherein said flexible insulating wrapper includes a thermoplastic
layer and a spacer strip formed on said thermoplastic layer as said
spacer portion.
12. The anti-abrasive flat flexible cable according to claim 11
wherein said spacer strip extends along said thermoplastic layer
over a half length of said thermoplastic layer.
13. The anti-abrasive flat flexible cable according to claim 11
wherein said housing includes a glass plate, and said spacer strip
has a hardness and a frictional coefficient on glass small enough
to substantially render no chip on contact.
14. The anti-abrasive flat flexible cable according to claim 13
wherein said spacer strip is made of a material selected from a
group consisting of Teflon, Nylon and polyoxylated methylene
(POM).
15. The anti-abrasive flat flexible cable according to claim 13
wherein said spacer strip is made of a composite material including
Nylon and POM.
16. The anti-abrasive flat flexible cable according to claim 9
further comprising a rigid supporting plate mounted to each of said
two opposite ends of said flexible conductive core for facilitating
the exertion of an external force to insert said flexible
conductive core into a slot of either of said first and second
devices.
17. An anti-abrasive flat flexible cable for use with an image
scanner for electrically connecting a carriage with a circuit
board, said flat flexible cable being bent at different positions
thereof with the movement of said carriage relative to said circuit
board under a glass platform, and comprising: a metal foil having a
first end electrically connected to said circuit board and a second
end electrically connected to said carriage for signal transmission
between said circuit board and carriage; a thermoplastic plastic
wrapper enclosing said metal foil with two opposite ends of said
metal foil exposed for electric connection with said circuit board
and said carriage, respectively; and a spacer strip selected from a
group consisting of Teflon, Nylon and polyoxylated methylene (POM),
and attached onto said thermoplastic plastic wrapper for isolating
said thermoplastic plastic wrapper from said glass platform.
18. The anti-abrasive flat flexible cable according to claim 17
further comprising a rigid supporting plate mounted to each of said
two opposite ends of said metal foil for facilitating the exertion
of an external force to insert said flexible conductive portion to
a slot of said circuit board or said carriage.
19. The anti-abrasive flat flexible cable according to claim 18
wherein said spacer strip is disposed between said rigid supporting
plate and said metal foil, and extends along said thermoplastic
plastic wrapper over a half length of said thermoplastic plastic
wrapper.
20. The anti-abrasive flat flexible cable according to claim 17
wherein said metal foil is a copper foil.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an anti-abrasive flat
flexible cable (FFC), and more particularly to an anti-abrasive
flat flexible cable adapted to be used with a thin image
scanner.
BACKGROUND OF THE INVENTION
[0002] A flat flexible cable is a common connecting wire between
electric devices. It is advantageous to be easily and reversibly
bent and stretched in a narrow and crowded space. For example, in a
flatbed image scanner, the moving-around carriage containing
therein optical and photoelectric devices is connected with the
circuit board through a flat flexible cable. Please refer to FIGS.
1A and 1B which are a top and a cross-sectional side views,
respectively, schematically showing the connecting operation of a
flat flexible cable in a flatbed image scanner. The flatbed scanner
includes an upper cover (not shown) and a lower housing 10. In the
lower housing, a carriage 11 containing therein optical and
photoelectric devices, a driving device 12 consisting of a motor
and gear set 121 and a rail set 122, a circuit board 13 including
various electronic elements, and a flat flexible cable 14
connecting the carriage 11 with the circuit board 13 are sealed
under a transparent scanning platform 15. The carriage 11 is moved
by the motor and gear set 121 along the rail set 122 to pass by and
scan a document or picture placed on the transparent platform 15 so
as to realize the image data of the document or picture.
[0003] Please refer to FIG. 2 which is a schematic cross-sectional
diagram showing the structure of a conventional flat flexible
cable. The flat flexible cable 14 includes a flexible copper foil
141, an insulating wrapper 142 made of a flexible plastic, and a
strengthening plate 143 made of a rigid plastic. The insulating
wrapper 142 surrounds the copper foil 141 with two ends of the
copper foil 141 exposed for electric contact with the carriage 11
and the circuit board 13, respectively. The strengthening plate 143
is mounted onto the end portion of the flat flexible cable 14 to
facilitate the insertion of the exposed copper foil into the
connecting slot (not shown) of the carriage 11 or the circuit board
13. Further referring to FIG. 1B again, a portion 142 of the flat
flexible cable 14 connecting to the circuit board 13 is fixed on
the bottom of the lower housing 10, and another portion 143
connecting to the carriage 11 is freely bent and stretched along
with the movement of the carriage 11.
[0004] During the movement of the carriage 11, the flat flexible
cable keeps on electrically connecting the carriage 11 with the
circuit board 13 for signal transmission. The configuration of the
flat flexible cable 14 changes all the time during the movement of
the carriage 11 along a scanning direction indicated by an arrow C.
It is understood at any moment, however, the distant end 141 of the
flat flexible cable 14 from the carriage 11, i.e. the U-turn
portion, raises up to the inner surface of the platform 15 due to
the flexible property thereof. Especially for an image scanner
using a contact image sensor (CIS) as an image pickup device which
requires close contact with the document on the platform 15, the
flat flexible cable 14 generally keeps in contact with the inner
surface of the platform 15 by a part thereof. For example, at a
start position where the carriage 11 is adjacent to the circuit
board 13, the flat flexible cable 14 is bent to have a U-turn point
at a position relative to the position A on the platform 15, as
shown in the solid line. On the other hand, at a scanning position
where the carriage 11 moves away from the circuit board 13, the
U-turn position shifts to a position B on the platform 15 along the
scanning direction C, as indicated by the dotted line. As a result,
abrasion is likely to occur due to the contact of the insulating
wrapper 142 of the flat flexible cable 14 with the transparent
platform 15 and the movement of the contact point from the position
A to the position B. In general, the insulating wrapper 142 is made
of a thermoplastic plastic material and the platform 15 is made of
glass. As known, a general thermoplastic plastic material has a
smaller hardness than the hardness of the platform 15, and the
frictional coefficient between the plastic and glass is not low
enough to avoid abrasion. The plastic chips resulting from the
abrasion by the glass platform may adversely affect the scanning
quality.
SUMMARY OF THE INVENTION
[0005] Therefore, an object of the present invention is to provide
an anti-abrasive flat flexible cable which isolates the plastic
wrapper from the glass platform to avoid abrasion.
[0006] A first aspect of the present invention relates to an
anti-abrasive flat flexible cable for use with an image scanner for
electrically connecting a carriage with a circuit board. The flat
flexible cable is bent at different positions thereof with the
movement of the carriage relative to the circuit board under a
scanning platform. The anti-abrasive flat flexible cable includes a
flexible conductive portion having a first end electrically
connected to the circuit board and a second end electrically
connected to the carriage for signal transmission between the
circuit board and carriage; a flexible insulating portion wrapping
around the flexible conductive portion for protecting the flexible
conductive portion; and a flexible spacer portion attached onto the
flexible insulating portion, and positioned between the flexible
insulating portion and the scanning platform for isolating the
flexible insulating portion from the scanning platform.
[0007] Preferably, the flexible conductive portion includes a
copper foil.
[0008] Preferably, the flexible insulating portion is made of a
thermoplastic plastic material.
[0009] Preferably, a hardness of the flexible spacer portion and a
frictional coefficient between the flexible spacer portion and the
scanning platform are small enough to substantially render no chip
on contact.
[0010] In an embodiment, the scanning platform is made of glass,
and the flexible spacer portion is made of a material selected from
a group consisting of Teflon, Nylon and polyoxylated methylene
(POM).
[0011] In another embodiment, the scanning platform is made of
glass, and the flexible spacer portion is made of a composite
material including Nylon and POM.
[0012] Preferably, the anti-abrasive flat flexible includes a rigid
supporting plate mounted to each of the first and second ends of
the flexible conductive portion for facilitating the exertion of an
external force to insert the flexible conductive portion to a slot
of the circuit board or the carriage. The flexible spacer portion
is disposed between the rigid supporting plate and the flexible
conductive portion, and extends along the flexible insulating
portion over a half length of the flexible insulating portion.
[0013] A second aspect of the present invention relates to an
anti-abrasive flat flexible cable used in a housing for signal
transmission between a first and a second devices. The
anti-abrasive flat flexible cable includes a flexible conducting
core for conducting an electronic signal; and a flexible insulating
wrapper enclosing the flexible conductive core for protecting the
flexible conductive core with two opposite ends of the flexible
conductive core exposed for electric connection to the first and
second devices, respectively, wherein the flexible insulating
wrapper includes a spacer portion possibly in contact with the
housing, and a hardness of the spacer portion and a frictional
coefficient between the spacer portion and the housing are small
enough to substantially render no chip on contact.
[0014] Preferably, the flexible conductive core is formed of a
copper foil, and the flexible insulating wrapper includes a
thermoplastic layer and a spacer strip formed on the thermoplastic
layer as the spacer portion.
[0015] Preferably, the spacer strip extends along the thermoplastic
layer over a half length of the thermoplastic layer.
[0016] When the flat flexible cable is used in a housing including
a glass plate, the spacer strip preferably has a hardness and a
frictional coefficient on glass small enough to substantially
render no chip on contact.
[0017] Preferably, the spacer strip is made of a material selected
from a group consisting of Teflon, Nylon and polyoxylated methylene
(POM). Alternatively, the spacer strip is made of a composite
material including Nylon and POM.
[0018] Preferably, the flat flexible cable further includes a rigid
supporting plate mounted to each of the two opposite ends of the
flexible conductive core for facilitating the exertion of an
external force to insert the flexible conductive core into a slot
of either of the first and second devices.
[0019] A third aspect of the present invention relates to an
anti-abrasive flat flexible cable for use with an image scanner for
electrically connecting a carriage with a circuit board. The flat
flexible cable is bent at different positions thereof with the
movement of the carriage relative to the circuit board under a
glass platform, and includes a metal foil having a first end
electrically connected to the circuit board and a second end
electrically connected to the carriage for signal transmission
between the circuit board and carriage; a thermoplastic plastic
wrapper enclosing the metal foil with two opposite ends of the
metal foil exposed for electric connection with the circuit board
and the carriage, respectively; and a spacer strip selected from a
group consisting of Teflon, Nylon and polyoxylated methylene (POM),
and attached onto the thermoplastic plastic wrapper for isolating
the thermoplastic plastic wrapper from the glass platform.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention may best be understood through the
following description with reference to the accompanying drawings,
in which:
[0021] FIG. 1A is a schematic top plane view of a typical flatbed
scanner;
[0022] FIG. 1B is a schematic cross-sectional side view of the
scanner of FIG. 1A;
[0023] FIG. 2 is a schematic cross-sectional side view of a
conventional flat flexible cable;
[0024] FIG. 3A is a schematic cross-sectional side view of a
preferred embodiment of a flat flexible cable according to the
present invention;
[0025] FIG. 3B is a schematic top plane view of the flat flexible
cable of FIG. 3A; and
[0026] FIG. 4 is a partial enlarged view of a flat flexible cable
for use with a CIS-type image scanner according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The present invention will now be described more
specifically with reference to the following embodiments. It is to
be noted that the following descriptions of preferred embodiments
of this invention are presented herein for purpose of illustration
and description only; it is not intended to be exhaustive or to be
limited to the precise form disclosed.
[0028] Please refer to FIGS. 3A and 3B which illustrate a preferred
embodiment of a flat flexible cable according to the present
invention. The flat flexible cable 34 includes a metal foil core
341 such as a copper foil, an insulating wrapper layer 342
enclosing the metal foil 341 with two opposite ends of the metal
foil core 341 exposed, two rigid supporting plates 343 mounted on
the opposite ends of the metal foil core 341, and a spacer strip
344 positioned between the rigid supporting plates 343 and the
insulating wrapper layer 342 and extending over a half length of
the insulating wrapper layer 342. The exposed ends of the metal
foil core 341 is to be inserted into respective slots of a circuit
board and a carriage of an image scanner for signal transmission
therebetween, referring to FIGS. 1A and 1B. When the flat flexible
cable 34 is used in a CIS-type image scanner in which the carriage
40 is close to the scanning platform 41, the flat flexible cable is
likely to be in contact with the glass scanning platform 41, as
shown in FIG. 4. The presence of the spacer strip 344 isolates the
vulnerable insulating wrapper layer 342 which is generally made of
a thermoplastic plastic material from the glass platform to avoid
chip. For assuring of the isolation effect, it is preferred that
the spacer strip 344 is present in the middle part of the cable 34
which may be bent during the movement of the carriage. Therefore,
in this embodiment, the insulating wrapper layer 342 extends over a
half length of the insulating wrapper layer 342. Alternatively, the
spacer strip 344 can be attached only to the middle part of the
insulating wrapper layer 342 by way of reliable adhesion. Further,
in order not to scratch the glass platform and be scratched by the
glass platform, the spacer strip 344 is preferably made of Teflon,
Nylon, polyoxylated methylene (POM) or any other material which is
less hard than glass and has small frictional coefficients on
glass.
[0029] The width of the spacer strip is not especially limited.
However, it is preferred to take the factors of processibility and
cost into consideration.
[0030] In addition to the structural improvement by providing a
spacer strip on the conventional flat flexible cable, it is
feasible to incorporate the spacer material mentioned above into
the material of the insulating wrapper to modify the insulating
wrapper so as to have a hardness and frictional coefficient on
glass small enough to render no significant amount of chips.
[0031] While the invention has been described in terms of what are
presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention need not be
limited to the disclosed embodiment. On the contrary, it is
intended to cover various modifications and similar arrangements
included within the spirit and scope of the appended claims which
are to be accorded with the broadest interpretation so as to
encompass all such modifications and similar structures.
* * * * *