Information
-
Patent Grant
-
6514101
-
Patent Number
6,514,101
-
Date Filed
Monday, June 25, 200122 years ago
-
Date Issued
Tuesday, February 4, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Patel; Tulsidas
- Hyeon; Hae Moon
Agents
- Rader, Fishman & Grauer PLLC
-
CPC
-
US Classifications
Field of Search
US
- 439 495
- 439 260
- 439 261
- 439 496
- 439 267
-
International Classifications
-
Abstract
An electrical connector for flexible printed board (1) has a housing (4) with an opening, and a cover (7) being rotatable about a predetermined pivotal axis for opening or closing the opening. A resilient piece (35) of a fork-shaped contact (23) has a first and a second branches (39, 41) branched from a free end (38) thereof. The second branch (41) includes a contact point coming into contact with a flexible printed board (2) inserted in an insertion space (3). One edge of the cover (7) is provided with a regulating portion (55) interposed between the first and second branches (39, 41). The regulating portion (55) restricts bidirectional displacements of the free end (38) of the resilient piece (35) within a predetermined range.
Description
TECHNICAL FIELD
The present invention relates to an electrical connector for flexible printed board called FPC (Flexible Printed Circuit).
BACKGROUND ARTS
There has been provided a technique for directly connecting a circuit on a printed circuit board with a contact of a connector. Conventionally, the connector of this type includes a synthetic-resin housing having an opening adapted to open upward, a plurality of fork-shaped contacts arranged to face into the opening, and a synthetic-resin cover which is pivotally movable to open/close the opening of the housing. The fork-shaped contact has a fixing piece and a resilient piece vertically opposed each other.
The connector of this type provides a wide insertion space for FPC as the flexible printed board, for example, when the cover is opened for insertion or removal of the FPC. This contributes an unconfined state of the FPC such that the FPC may be inserted in place without using an inserting force or pulled out without using a pulling force. Thus, the FPC is prevented from being damaged during insertion or removal thereof.
As the connector allowing the insertion or removal of the FPC under unconfined conditions, there have been provided a variety of connectors of a lower contact point type. In the connector of lower contact point, a contact point is provided only at the resilient piece on the lower side. One edge of the cover in closed position is clamped between the FPC resting on the resilient piece and the fixing piece on the upper side so that the FPC is pressed against the resilient piece by means of the clamped edge of the cover.
On the other hand, there is a demand for a connector of an upper contact point type which features an increased freedom with respect to the connection with the FPC and which provides the contact point only at the resilient piece disposed on the upper side.
The following publication has been published by the Japanese Patent Office pertaining a type of connector adapted for connection of stripped conductor ends of a multiple conductor flat cable via the upper and lower contact points.
Country: Japan
Publication Number: 1(1989)-315976 (unexamined)
Published Date: Dec. 20, 1989.
The connector of the above official gazette has a lever arm extended from a distal end of the resilient piece to place above one edge of the cover in closed position. When the cover is opened, the edge of the cover pushes up the lever arm to expand a gap between the two contact points, thereby facilitating the insertion or removal of FPC. Additionally, the lever arm applies a resilient reaction force to the one edge of the cover in open position, thereby maintaining the cover in open position.
In the connector of the above official gazette, however, an upward displacement of the resilient piece is not restricted. Hence, the resilient piece is subjected to plastic deformation when pushed up by some external force. As a result, the resilient piece is incapable of providing a sufficient contact pressure on the FPC.
In view of the foregoing, the present invention has been accomplished and has an object to provide an upper contact point type connector for flexible printed board which ensures a sufficient contact pressure by preventing an excessive deformation of the contact.
DISCLOSURE OF THE INVENTION
For achieving the above object, an electrical connector for flexible printed board according to a preferred embodiment of the invention comprises: a synthetic-resin housing having an opening; a plurality of fork-shaped contacts being arranged to face into the opening, each of the contact having a resilient piece and a fixing piece in opposed relation; an insertion space for flexible printed board defined between the resilient piece and the fixing piece; and a synthetic-resin cover being rotatable around a predetermined pivotal axis to open or close the opening. The plural fork-shaped contacts include a fork-shaped contact including a first and a second branches branched from a free end of the resilient piece. The second branch adjoins the insertion space. The second branch includes a contact point pressed into contact with a flexible printed board inserted in the insertion space. One edge of the cover includes a regulating portion interposed between the first and the second branches for bidirectionally restricting a range of displacement of the free end of the resilient piece.
According to the embodiment hereof, the range of displacement of the free end of the resilient piece can be bidirectionally restricted by the regulating portion disposed at the one edge of the cover sandwiched between the first and the second branches. Therefore, an excessive deformation of the contact may be prevented. As a result, the so-called connector of upper contact point type can ensure a sufficient contact pressure on the flexible printed board at all times. Further, damage on the contact or the flexible printed board is prevented, the damage resulting from the excessive deformation of the contact.
It is particularly preferred that the regulating portion includes a cam surface for pushing the first branch into displacement thereby expanding the insertion space in conjunction with the opening of the cover. In this case, a wide insertion space for flexible printed board is provided when the cover is opened.
It is further preferred that the cam surface moves away from the first branch in conjunction with the closing of the cover. This eliminates the displacement of the first branch caused by the cam surface when the cover is closed. Therefore, the resilience of the resilient piece may be utilized to provide a sufficient contact pressure on the flexible printed board.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a disassembled perspective view showing a connector for flexible printed board according to one embodiment of the invention and an FPC as a flexible printed circuit board;
FIG. 2
is a partially cut-away plan view showing the connector with its cover closed;
FIG. 3
is a sectional view taken on the line III—III in
FIG. 2
for showing the connector with its cover opened, where hatch lines representing a section of a reinforcement tab are omitted;
FIG. 4
is a sectional view taken on the line IV—IV in
FIG. 2
, where hatch lines representing a section of a first contact are omitted;
FIG. 5A
is a sectional view taken on the line V—V in
FIG. 2
whereas
FIG. 5B
is an enlarged view of a principal portion, where hatch lines representing a section of a second contact are omitted;
FIG. 6
is a perspective view showing the connector with its cover closed;
FIG. 7
is a partially cut-away plan view of a cover;
FIG. 8
is a plan view showing an upper surface of an FPC end portion;
FIG. 9A
is a sectional view corresponding to
FIG. 5A
for showing the connector with its cover opened, and
FIG. 9B
is an enlarged view of a principal portion thereof, where hatch lines representing the section of the second contact are omitted; and
FIGS. 10 and 10B
are sectional views corresponding to
FIG. 5A
for showing the connector connected with the FPC, where hatch lines representing the section of the second contact are omitted.
BEST MODE FOR CARRYING OUT THE INVENTION
A preferred embodiment of the invention will be described with reference to the accompanying drawings.
Referring to
FIGS. 1 and 2
, a connector
1
for flexible printed board (hereinafter, simply referred to as “connector 1”) comprises a synthetic-resin housing
4
defining an insertion space
3
in which a flexible printed circuit board
2
(hereinafter, simply referred to as “FPC 2”) is detachably inserted. A front half portion of the housing
4
upwardly opens via an opening
6
of a top plate
5
of the housing
4
and is provided with a cover
7
, a molded article of synthetic resin, which is pivotally movable about a pivotal axis A
1
to open or close the opening
6
.
As shown in
FIG. 8
, a plurality of first and second conductive connection portions
17
,
18
defined by a printed circuit pattern are exposed from an end of an upper surface
2
a
of the FPC
2
. The first and second conductive connection portions
17
,
18
are arranged in two rows in a zigzag fashion, respectively connected with first and second contacts
22
,
23
of the connector
1
. Indicated at
17
a,
18
a
are lines along which respective contact pressures between the first and second conductive connection portions
17
,
18
and their corresponding contacts
22
,
23
are established.
Pivot shafts A are exposed from opposite ends of the cover
7
, respectively. As seen in
FIG. 7
, the pivot shafts A are defined by opposite ends of a metallic wire
45
embedded in the cover
7
. Indicated at
51
is a metallic reinforcement wire which is also embedded in the cover
7
. The wire
51
includes projections C at opposite ends thereof which are retained by a molding die during a molding process of the cover
7
. Indicated at
53
,
54
are apertures for partially exposing the wires
45
,
51
to the outside of the cover
7
, respectively.
Opposite side plates
8
,
9
of the housing
4
define lateral sides of the insertion space
3
. Fixing holes
11
(shown in
FIGS. 2 and 3
but not in
FIG. 1
) open into respective front side surfaces of the side plates
8
,
9
for fixingly receiving reinforcement tabs
10
from front. The reinforcement tabs
10
are formed of metal plates for supporting a pair of pivot shafts A projecting laterally outwardly of the cover
7
.
Now referring to
FIG. 3
, the reinforcement tab
10
comprises a main body
12
, a pivotal support portion
14
and a hook-shaped fixing portion
15
. The main body
12
is inserted into the fixing hole
11
from front so as to be fixed to place via a locking projection. The pivotal support portion
14
is comprised of a U-shaped notch defined by an extension piece
13
extending upward from a front end of the main body
12
, and pivotally supports the pivot shaft A. The fixing portion
15
extends downward from the front end of the main body
12
to be soldered to a substrate surface. The main body
12
is formed with a lock notch
50
at its front edge. The lock notches
50
serve to lock the cover
7
in the close position through engagement with the projection C defined by the opposite ends of the wire
51
. As received by the U-shaped notch as the pivotal support portion
14
, the pivot shaft A is retained in the U-shaped notch by an abutting portion
60
of the housing
4
pressed against the pivot shaft A.
Returning to
FIGS. 1 and 2
, guide walls
19
,
20
upstand from opposite side edges of a front portion of a bottom plate
16
of the housing
4
. When the cover
7
is closed, the guide walls
19
,
20
are received by corresponding U-shaped gaps
21
defined at side edges of the cover
7
, thereby restricting the lateral movement of the cover
7
. Within the insertion space
3
of the housing
4
, a plurality of first and second fork-shaped contacts
22
,
23
are alternately arranged in two rows in a zigzag fashion across the housing
4
.
Referring to
FIGS. 1
,
2
and
4
, the first contact
22
is comprised of a metallic member and fixedly inserted in the insertion space
3
of the housing
4
from front. Referring to
FIG. 4
, the first contact
22
comprises a fixing piece
25
inserted, from front, into a receiving groove
24
defined in an upper surface of the bottom plate
16
of the housing
4
, and a resilient piece
26
located in a rear half portion of the insertion space
3
at place above the fixing piece
25
.
A locking piece
27
with a locking projection extends rearwardly from an interconnection between the fixing piece
25
and the resilient piece
26
. The locking piece
27
is inserted in a fixing hole
28
of the housing
4
so as to be fixed to place. The fixing piece
25
is provided with a lead portion
29
of an inverted T-shape at its front end. The lead portion
29
is soldered to the substrate surface on which the inventive connector
1
is mounted, while engaging a front edge of the bottom plate
16
of the housing
4
for preventing the upward dislocation of the fixing piece
25
. Chevron-shaped projections
30
,
31
are formed at the fixing piece
25
and the resilient piece
26
in opposed relation, respectively, for clamping the inserted FPC
2
therebetween thereby to ensure a contact pressure on the FPC
2
.
Referring to
FIGS. 1 and 7
, the cover
7
is of a substantially rectangular plate, having a first and a second edges
42
,
43
in opposed relation. The aforesaid pair of pivot shafts A project from laterally opposite ends
44
,
44
of the first edge
42
, respectively. The pivot shaft pair A are comprised of exposed opposite ends
46
,
46
of the metallic wire
45
which is embedded in the cover during the molding thereof. The whole body of the wire
45
takes the form of a crank, an intermediate portion
47
of which extends parallel to the first edge
42
as spaced a distance therefrom.
As shown in
FIGS. 9A and 9B
, the first edge
42
of the cover
7
is formed with a plurality of through holes
40
transversely arranged for allowing ingress or egress of individual upper branches
39
of resilient pieces
35
of the second contacts
23
which will be described hereinafter. In
FIG. 7
, a portion between the first edge
42
and the through hole
40
and closer to the first edge
42
than the through hole
40
defines a regulating portion
55
for restricting a movable range of the resilient piece
35
. Each of the projection pair C projects from a respective one of laterally opposite ends
49
,
49
of the second edge
43
of the cover
7
.
The pair of projections C are comprised of exposed opposite ends
52
,
52
of the straight metallic reinforcement wire
51
. The reinforcement wire
51
is embedded in the cover
7
during the molding process thereof and extended parallel to the second edge
43
as spaced a distance therefrom. The projection C exposedly extends downwardly and rearwardly from the lateral end
49
of the second edge
43
.
Referring to
FIG. 7
, the wire
45
is exposed via one or more apertures
53
whereas an intermediate portion of the wire
51
is exposed via one or more apertures
54
. These apertures
53
,
54
play the following role. In order to insert the metallic wires
45
,
51
in an article being molded to give the cover
7
with the wires embedded therein, the metallic wires
45
,
51
must be supported in a given position within a molding die. The apertures
53
,
54
permit wide support pins (insert pins) to be placed in the molding die at places in correspondence thereto. Thus, the wires
45
,
51
may be stably supported within the molding die. As a result, the molded article has high positional accuracies for the pivot shafts A and projections C which are comprised of the opposite ends of the wires
45
,
51
.
Referring to
FIGS. 1
,
2
and
5
A, the second contact
23
is comprised of a metallic member which is inserted into the insertion space
3
of the housing
4
from rear side and fixed to place. Referring to
FIG. 5A
, the second contact
23
comprises a fixing piece
33
, the resilient piece
35
, a main body
36
and a lead portion
37
. The fixing piece
33
has a locking projection and is fixedly inserted, from rear, into a fixing hole
32
at a lower part of the housing
4
. The resilient piece
35
is inserted, from rear, into a receiving groove
34
defined in a lower surface of a top plate
5
of the housing
4
and is located above the fixing piece
33
. The main body
36
interconnects rear ends of the fixing piece
33
and the resilient piece
35
. The lead portion
37
extends diagonally rearward from the main body
36
to be soldered to the substrate surface.
Respective front ends of the fixing piece
33
and the resilient piece
35
reach a midportion of the housing
4
with respect to a front-to-rear direction thereof. A front end
38
, or a free end of the resilient piece
35
, is substantially branched into a U-shape, thus including an upper branch
39
and a lower branch
41
. The upper branch
39
provides a first branch whereas the lower branch
41
provides a second branch. The lower branch
41
includes a contact point
48
pressed into contact with the second conductive connection portion
18
of FPC
2
.
On the other hand, the first edge
42
of the cover
7
includes the regulating portion
55
which is located between the respective upper branches
39
and lower branches
41
of the resilient pieces
35
thereby restricting the range of displacement of the resilient pieces
35
. Each regulating portion
55
is shaped like a hook in section. Adjoining each regulating portion
55
is the through hole
40
allowing the ingress or egress of the upper branch
39
in conjunction with the closing or opening of the cover
7
.
Referring to
FIG. 5B
, the regulating portion
55
includes a bearing surface
56
for bearing the upper branch
39
of the resilient piece
35
, the upper branch being in a free state when the cover
7
is closed without the FPC
2
inserted. A recess
58
is formed in a surface
57
opposite to the bearing surface
56
. The recess
58
serves to restrict an upward displacement of the lower branch
41
within a predetermined range P when the cover
7
is closed. Indicated at A
1
is the pivotal axis as the center of the pivot shaft A. The pivotal axis A
1
is positioned between the upper branch
39
and the lower branch
41
as extending through the regulating portion
55
. The contact point
48
of the lower branch
41
is designed to position directly under the pivotal axis A
1
.
The regulating portion
55
further includes a cam surface. A cam surface
59
adjoins the bearing surface
56
, while defining a part of an inside wall of the through hole
40
. As shown in
FIGS. 9A and 9B
, the cam surface
59
acts to push up the upper branch
39
when the cover
7
is opened, thereby expanding the insertion space
3
for FPC located under the lower branch
41
.
FIGS. 10A and 10B
show a state in which the cover
7
is closed with the FPC
2
inserted in the insertion space
3
. The FPC
2
is clamped between the bottom plate
16
of the housing
4
and the contact point
48
of the lower branch
41
of the second contact
23
. As seen in
FIG. 10B
, the lower branch
41
along with the upper branch
39
are lifted up by a reaction force derived from the lower branch contacting via the contact point
48
, while the lower branch
41
enters the recess
58
of the regulating portion
55
. In this state, a gap is produced between the upper branch
39
and the bearing surface
56
whereas a gap is produced between the lower branch
41
and the recess
58
.
Should the front end of the resilient piece
35
be pressed downward by some external force, the upper branch
39
bears against the bearing surface
56
, thereby preventing any further deformation of the resilient piece. On the other hand, should the front end of the resilient piece
35
be lifted up by some external force, the lower branch
41
abuts against the recess
58
, thereby preventing any further deformation of the resilient piece.
According to the embodiment, the range of displacement of the resilient piece
35
can be restricted in both the upward and downward directions by the regulating portion
55
of the cover
7
interposed between the upper branch
39
and the lower branch
41
. Thus, an excessive deformation of the second contact
23
can be prevented. As a result, the connector of upper contact point type is capable of constantly achieving a high contact pressure on the FPC
2
. In addition, the embodiment is adapted to prevent damage on the second contact
23
or FPC
2
caused by the excessive deformation of the second contact
23
.
According to the embodiment, the first and second conductive connection portions
17
,
18
of the FPC
2
are arranged in a zigzag pattern, as shown in
FIG. 8
, so that the first conductive connection portions
17
are located ahead of the second conductive connection portions
18
with respect to an insertion direction X of the FPC
2
. Accordingly, the second fork-shaped contacts
23
corresponding to the conductive connection portions
18
located on the rear side with respect to the insertion direction X are located ahead of the first fork-shaped contacts
22
with respect to a removal direction Y of the FPC
2
. As a result, the resilient piece
35
of the second contact
23
has a longer span, thus being more susceptible to deformation by the external force. However, the embodiment is particularly effective in that the range of displacement of the free end
38
of the resilient piece
35
is directly restricted by the regulating portion
55
interposed between the upper branch
39
and the lower branch
41
.
When the cover
7
is closed, the resilient piece
35
must present such a resilience as to be pressed into contact with the FPC
2
. Considering the dimensional tolerances of individual parts, it is desirable to define the greatest possible wide range for movement of the resilient piece
35
. Therefore, it is preferred that the first edge
42
of the cover
7
has the minimum possible thickness. However, the first edge
42
of the cover
7
is required of a given thickness in order to ensure a predetermined strength thereof. In view of the foregoing, the embodiment provides the recess
58
in the first edge
42
of the cover
7
for allowing the ingress of the lower branch
41
thereinto when the cover
7
is closed, thereby offering the following merit. That is, a connector of an ultra thin design having a height of about 1.0 mm, for example, is capable of ensuring the strength of the first edge
42
of the cover
7
as well as providing the free end
38
of the resilient piece
35
with a sufficient movable range of about 0.15 to 0.2 mm, for example, for achieving a sufficient contact pressure. Incidentally, even the connector of the thin design conventionally has a height of 2.0 to 3.0 mm.
Since the pivot shaft A of the cover
7
is formed of a metal, the cover is less likely to break. The cover
7
is also prevented from bending by the metallic wire
45
embedded along the overall widthwise length (transverse direction) of the cover
7
. This ensures a sufficient contact pressure between the FPC
2
and the contact point
48
of the resilient piece
35
of the second contact
23
and also prevents the cover
7
from disengaging from the housing
4
. Since the wire
45
is inserted into the cover
7
at the time of resin molding thereof, a high adhesion between the wire
45
and the cover
7
is achieved, resulting in a more positive prevention of the deformation of the cover
7
.
In addition to the wire
45
, the reinforcement wire
51
is further provided for reinforcing the cover
7
, so that the bending of the cover
7
is more positively prevented. Particularly, the pair of metallic reinforcement tabs
10
,
10
, the wire
45
and the reinforcement wire
51
substantially define a rectangle when the cove
7
is closed. Thus, the cover
7
is reliably fixed so that the connector
1
has a notably increased strength. As a result, the connector is assuredly able to apply the contact pressure on the FPC
2
.
If the wire
45
was extended straight through the first edge
42
, the first edge
42
would contain therein the wire
45
to be increased in the overall thickness thereof. Hence, the regulating portion
55
at the first edge
42
would also be increased in thickness so that the second contact
23
has an increased gap between the upper and lower branches
39
,
41
of the resilient piece
35
thereof. This would result in an increased height of the connector
1
. According to the embodiment hereof, the intermediate portion
47
of the wire
45
takes the form of a channel such that the wire
45
is spaced a distance away from the first edge
42
of the cover
7
where the regulating portion
55
is disposed. Therefore, as shown in
FIG. 5B
, the regulating portion
55
is decreased in thickness, permitting the implementation of the thin design of the connector
1
. This is also effective to prevent a short circuit between the second contact
23
and the wire
45
.
It is to be noted that the present invention is not limited to the foregoing embodiment. For instance, the connector of the foregoing embodiment may be mounted in a manner that top-bottom positions of the connector are oriented in a different direction from that illustrated by the embodiment.
Further, the first contact may be configured the same way as the second contact. Alternatively, the connector may dispense with the first contact, thus solely including the second contact.
Furthermore, the pair of projections C may be constructed from a resin material integrally with the cover
7
. On the other hand, the wire
51
for reinforcement purpose may be dispensed with so that the cover
7
is reinforced by a single wire
45
alone. Other various changes and modifications may be made within the scope of the invention.
Claims
- 1. An electrical connector for a flexible printed board comprising:a synthetic-resin housing having an opening, a plurality of fork-shaped contacts being arranged to face into the opening, each of the contacts having a resilient piece and a fixing piece in opposed relation, an insertion space for the flexible printed board defined between the resilient piece and the fixing piece, and a synthetic-resin cover being rotatable around a predetermined pivotal axis to open or close the opening, wherein each fork-shaped contact includes a U-shaped portion including a first branch and a second branch branched from a free end of the resilient piece, wherein the second branch adjoins the insertion space; wherein the second branch includes a contact point pressed into contact with the flexible printed board inserted in the insertion space, and wherein one edge of the cover includes a regulating portion interposed between the first and the second branches for bidirectionally restricting a range of displacement of the free end of the resilient piece.
- 2. The electrical connector for flexible printed board as claimed in claim 1, wherein the regulating portion includes a cam surface for pushing the first branch into displacement with the opening of the cover so as to expand the insertion space in conjunction.
- 3. The electrical connector for flexible printed board as claimed in claim 2, wherein the cam surface moves away from the first branch in conjunction with the closing of the cover.
- 4. The electrical connector for flexible printed board as claimed in claim 2, wherein the cover includes a through hole allowing the ingress or egress of the first branch thereinto or therefrom when the cover is closed or opened, a part of the through hole being defined by the cam surface.
- 5. The electrical connector for flexible printed board as claimed in claim 1, wherein the regulating portion includes a recess for restricting the displacement of the second branch within a predetermined range as allowing the ingress of the second branch thereinto, when the cover is closed with a flexible printed board inserted in place.
- 6. The electrical connector for flexible printed board as claimed in claim 1, wherein the regulating portion includes a bearing surface for bearing the first branch when the cover is closed without a flexible printed board inserted in place.
- 7. The electrical connector for flexible printed board as claimed in claim 6, wherein a recess is formed in an opposite surface to the bearing surface.
- 8. The electrical connector for flexible printed board as claimed in claim 6, wherein the bearing surface and a cam surface adjoins each other.
- 9. The electrical connector for flexible printed board as claimed in claim 1, wherein the predetermined pivotal axis extends through the regulating portion.
- 10. The electrical connector for flexible printed board as claimed in claim 1,wherein the cover includes a metallic wire partially embedded therein during molding thereof, and wherein a pair of pivot shafts along the predetermined pivotal axis are provided at a pair of opposite ends of the wire.
- 11. The electrical connector for flexible printed board as claimed in claim 10, wherein the wire includes an intermediate portion between the pair of opposite ends thereof, the intermediate portion being substantially shaped like a channel.
- 12. The electrical connector for flexible printed board as claimed in claim 1, wherein the contact point of the fork-shaped contact having the first and the second branches is located ahead of a contact point of the other fork-shaped contact with respect to an insertion direction of a flexible printed board.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11/304515 |
Oct 1999 |
JP |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/JP00/07406 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO01/31754 |
5/3/2001 |
WO |
A |
US Referenced Citations (5)
Foreign Referenced Citations (4)
Number |
Date |
Country |
01-315976 |
Dec 1989 |
JP |
6-77186 |
Oct 1994 |
JP |
09-185977 |
Jul 1997 |
JP |
09-283240 |
Oct 1997 |
JP |