Information
-
Patent Grant
-
6344620
-
Patent Number
6,344,620
-
Date Filed
Tuesday, April 17, 200123 years ago
-
Date Issued
Tuesday, February 5, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Armstrong, Westerman, Hattori, McLeland & Naughton, LLP
-
CPC
-
US Classifications
Field of Search
US
- 200 4
- 200 5 R
- 200 6 A
- 200 17 R
- 200 18
- 200 335
- 200 339
- 345 157
- 345 161
-
International Classifications
-
Abstract
A multidirectional input device with a built-in push-down switch, capable of reducing the number of parts, eliminating soldering for connection with a mounting substrate, and reducing an assembly cost of devices using the multidirectional input device, wherein a key top (70) provided under an operating member (30) operating a set of upper and lower rotating members (40a) and (40b) is installed through the bottom plate part (11) of a case (10) and pushed down by the operating member (30), and a switch main body (110) operated by the key top (70) and provided on a substrate (100), on which the case (10) is installed, comprises a fixed contact formed on the substrate (100) and a dome-shaped moving contact covering the fixed contact and fixed onto the substrate.
Description
FIELD OF THE INVENTION
The present invention relates to a multi-directional input apparatus for inputting various signals by operating an operating member which is operated in arbitrary circumferential direction.
BACKGROUND ART
A multi-directional input apparatus of this type called joystick comprises a case secured on a board, a set of upper and lower turning members having long holes each extending in a direction perpendicular to the turning direction, an operating member passing through the long holes of the set of upper and lower turning members for turning the turning members by operating the operating member in an arbitrary circumferential direction, a spring compressed and accommodated in the case for resiliently holding the operating member in its neutral position, and a set of signal output means for outputting a signal corresponding to the turning angle of each the turning member.
As the set of signal output means, a volume such as an electric sensor, a magnetic sensor, optical sensor or the like is used, and the volume is relatively commonly used in terms of costs and the like. Multi-directional input apparatuses using the volume as the set of signal output means are described in Japanese Patent Application Laid-open No. S61-198286, Japanese Utility Model Publication No. H6-43963, and Japanese Utility Model Publication No. H7-27608.
Some of this kind of multi-directional input apparatuses have operating members which can vertically move, and the pushdown switches are operated by pushing down operation of the operating members. The multi-directional input apparatus having such a pushdown switch is described in Japanese Patent Application Laid-open No. H10-283885. In the multi-directional input apparatus having the pushdown switch described in Japanese Patent Application Laid-open No. H10-283885, the pushdown switch comprises a pushdown member provided below the operating member, ad a switch body provided below the pushdown member on a bottom plate of a case.
In the multi-directional input apparatus having the pushdown switch described in Japanese Patent Application Laid-open No. H10-283885, however, the pushdown switch is accommodated in the case including the switch body. Therefore, when the multi-directional input apparatus is mounted, it is necessary to solder the switch body in the apparatus to a print circuit on the board.
Further, in a general multi-directional input apparatus having the pushdown switch, a normal pushdown switch unit is used as the pushdown switch. The normal pushdown switch unit comprises six members, i.e., a frame, a body, a terminal, a key top, a snap plate and a cover. Therefore, the pushdown switch becomes expensive, and this increases the manufacturing cost of the multi-directional input apparatus.
Further, the volume used as the one set of signal output means has the following problems.
That is, although the volume is inexpensive as compared with other signal output means, the volume requires a large number of parts (usually five parts), a rate of cost occupied by the volume in the multi-directional input apparatus is still high. Further, since it is necessary to use solder between the multi-directional input apparatus and a board onto which the multi-directional input apparatus is mounted, this increases the manufacturing cost of equipment which uses the multi-directional input apparatus.
The present invention has been accomplished in view of these circumstances, and it is a first object of the present invention to provide a multi-directional input apparatus in which although the pushdown switch is provided, the switch can easily be mounted to the board without soldering.
It is a second object of the invention to provide a multi-directional input apparatus having a small number of parts constituting the pushdown switch.
It is a third object of the invention to provide a multi-directional input apparatus in which the number of parts of signal output means is small, and it is unnecessary to solder the signal output means to the board.
DISCLOSURE OF THE INVENTION
To achieve the above object, the present invention provides a multi-directional input apparatus comprising a case secured on a board; a set of upper and lower turning members supported in the case such that the turning members can turn into two intersecting directions and each having a long hole extending in a direction perpendicular to the turning direction; an operating member which can be pushed down and which passes through each of the long holes of the set of upper and lower turning members, the operating member turning each of the turning members when the operating member is operated in arbitrary direction therearound; a holding mechanism for resiliently holding the operating member and/or the turning members at a neutral position; a set of signal output means for outputting signal corresponding to a turning angle of each of the turning members; and a pushdown switch which is switched when the operating member is pushed down; wherein the pushdown switch comprises a combination of a key top which is vertically movably provided below the operating member such as to pass through a bottom plate of the case, and a switch body which is located below the key top and mounted on the board, and which is operated when the operating member is pushed down and the key top is moved down.
In such a multi-directional input apparatus, the operating member passes through the bottom plate of the case, if the operating member is pushed down, the key top is moved down, thereby operating the switch body on the board. Therefore, when the multi-directional input apparatus is mounted, it is unnecessary to solder the switch to the board.
In the other multi-directional input apparatus of the invention, the switch body comprises a combination of a stationary contact formed on the board and a domical movable contact piece which can be resiliently deformed and secured on the stationary contact. With this structure, the number of parts constituting the switch body can largely be reduced.
According to another multi-directional input apparatus of the invention, the movable contact piece is secured on the stationary contact by pasting a resin sheet on the board from above the movable contact piece. With this structure, it is easy to assemble the switch body on the board.
According to another multi-directional input apparatus of the invention, the signal output means is constituted such that gears are mounted to one ends of the set of upper and lower turning members, straight-ahead sliders capable of moving along two side surfaces of the case and the board are mounted below the gears, teeth meshing with the gears are provided on upper surfaces of the straight-ahead sliders, and the contacts which can slide to come into contact with resistance circuits to constitute volumes together with the resistance circuits are mounted on lower surfaces of the straight-ahead sliders.
With this structure, when the operating member is operated and the turning members are turned, the gears provided on the one ends of the turning members are rotated. With the rotation, the straight-ahead sliders are moved and the contacts slide on the resistance circuits formed on the surface of the board, and the function as a volume can be obtained.
Since the resistance circuits are provided on the side of the board, the number of signal output means is also reduced, and it is unnecessary to solder the resistance circuit to the board. Especially, the accommodating portion for accommodating the straight-ahead slider can be integrally formed on the case. The gear can also be integrally formed on the case. By forming these members integrally into the multi-directional input apparatus, the number of parts constituting the volume can be reduced into two, i.e., the straight-ahead slider and the contact.
The accommodating portion for accommodating the straight-ahead slider may be separately mounted to the case, but it is preferable to integrally form the accommodating portion on the side surface of the case to reduce the number of parts.
A fan-like member having an arc surface formed with teeth is preferable as the gear because the apparatus can be made small. It is preferable that it is integrally formed on the end of the turning member because the number of parts is reduced.
The basic structure of the multi-directional input apparatus is not limited. For example, the holding mechanism for resiliently holding the operating member at the neutral position may directly hold the operating member at the neutral position, or may indirectly hold the set of upper and lower operating members at the neutral position using spring, or may directly hold both the operating members at the neutral position. The spring may be disposed on either upper or lower one of the sets of the upper and lower turning members.
Preferable signal output means is a slide type volume-integral means employed for the multi-directional input apparatus according to claim 4 because the number of parts can be reduced, and the assembling operation is simplified. A signal output means having a general variable resistance unit may be used, and other means such as a magnetic type means or optical type means may also be used of course.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a plan view of a multi-directional input apparatus according to an embodiment of the present invention;
FIG. 2
is a sectional view taken along a narrow A—A in
FIG. 1
;
FIG. 3
is a sectional view taken along a narrow B—B in
FIG. 1
;
FIG. 4
is a sectional view taken along an arrow C—C in
FIG. 1
;
FIG. 5
is a bottom view of the multi-directional input apparatus;
FIG. 6
is a pattern circuit diagram of a resistant circuit combined with the multi-directional input apparatus; and
FIG. 7
is an enlarged view of a portion D in FIG.
2
.
EXPLANATION OF SYMBOLS
|
10
case
|
10a
lower case
|
10b
upper case
|
15
body
|
16
slider accommodating portion
|
20A, 20B
volume section (signal output means)
|
30
operating member
|
40A, 40B
turning member
|
41A, 41B
turning shaft
|
42A
semi-spherical portion
|
43A, 43B
long hole
|
44A, 44B
gear
|
45A, 45B
teeth
|
50
hoisting and lowering slider
|
60
spring
|
70
key top constituting pushdown switch
|
80
straight-ahead slider
|
82
teeth
|
90
contact
|
100
board
|
110
switch body of pushdown switch
|
111
stationary contact
|
112
movable contact piece
|
120
resistance circuit
|
|
EMBODIMENT OF THE INVENTION
An embodiment of the present invention will be explained based on the drawings below. As shown in
FIG. 1
, in a multi-directional input apparatus of a first embodiment of the invention, a case
10
is secured on a board
100
(see FIG.
6
), and the case
10
is integrally provided at its two side with a set of volume sections
20
A and
20
B as signal output means.
As shown in
FIGS. 2 and 3
, accommodated in a body of the case
10
excluding the volume sections
20
A and
20
B are a rod-like operating member
30
inclingly operated in arbitrary circumferential direction around its lower portion, a set of upper and lower turning members
40
A and
40
B, a hoisting and lowering slider
50
and a spring
60
for resiliently holding the operating member
30
at its neutral position, and a key top
70
which is pushed down by the operating member
30
.
The key top
70
constitute a pushdown switch together with a switch body
110
on the board
100
. Straight-ahead sliders
80
and
80
are provided in volume sections
20
A and
20
B.
The box-like case
10
secured on the board
100
is of a two-piece structure comprising a lower case
10
a
forming a bottom plate of the case
10
and an upper case
10
b
placed on the lower case
10
a
from above.
The lower case
10
a
has a substantially quadrangle bottom plate
11
. The bottom plate
11
is provided at its four corners with pawls
12
which are upwardly projecting for securing the uppercase
10
b
to the bottom plate
11
. A support
13
is projected from a central portion of sides of the bottom plate
11
for supporting the turning members
40
A and
40
B. The bottom plate
11
is provided at its central portion with a cylindrical guide
14
for vertically guiding a key top
70
.
The upper case
10
b
includes a box-like body
15
which is to be put on the lower case
10
a
and whose bottom is opened. The upper case
10
b
also includes slider accommodating portions
16
and
16
. The body
15
is provided at its ceiling with and opening
17
through which the operating member
30
projects. A plurality of openings into which pawls
12
of the lower case
10
a
are formed around the opening
17
. The body
15
is provided at its side walls with notches into which the support
13
of the lower case
10
a
is fitted.
As shown in
FIGS. 1
,
2
,
4
and
5
, each of the slider accommodating portions
16
and
16
accommodating the straight-ahead slider
80
is a regular hexahedronal box expanded from the lower side surface sideway, and a lower surface of the slider accommodating portion
16
is entirely opened. Each of the slider accommodating portions
16
and
16
is provided at its upper surface with a slit-like opening
18
along a side surface of the body
15
.
When the upper case
10
b
is put on the lower case
10
a,
the pawls
12
of the lower case
10
a
engage an opening if the body
15
of the upper case
10
b
so that the lower case
10
a
and the upper case
10
b
are secured to each other. When the support
13
of the lower case la is fitted to the notches of the body
15
of the uppercase
10
b,
each of the side surfaces of the body
15
is formed with a circle opening for supporting opposite end shafts of the turning members
40
A and
40
B.
As shown in
FIGS. 2 and 3
, the operating member
30
includes a rod
31
having a circular cross section, a turning shaft
32
continuously formed on a lower portion of the rod
31
, a large-diameter disc
33
continuously formed on a further lower portion of the turning shaft
32
, and a downwardly swelling semi-circular projection
34
formed on a central portion of a lower surface of the disc
33
. The disc
33
has an upwardly swelling semi-circular cross section, and is projecting in two directions perpendicular to the turning shaft
32
. An axial center of the turning shaft
32
crosses the center of the downwardly swelling semi-circular projection
34
.
The upper turning member
40
A has turning shafts
41
A and
41
A, and an upwardly swelling arc
43
A. The arc
43
A is provided with a long hole
43
A extending toward the turning center axis. The long hole
43
A functions as a guide hole for the operating member
30
. A gear
44
A is integrally formed on a tip end surface of one of the turning shafts
41
A and
41
A. The gear
44
A projects sideway of the body
15
, and is located above the opening
18
of one of the slider accommodating portions
16
and
16
. The gear
44
A has a fan-like shape whose arc surface is directed downward, and the arc surface is formed with spur wheel teeth
45
A.
The lower turning member
40
B is combined with below the upper turning member
40
A perpendicularly. The turning member
40
B is provided at its opposite ends with turning shafts
41
B and
41
B each having a circular cross section. The turning member
40
B is provided with an upwardly swelling semi-spherical portion
42
B formed between the turning shafts
41
B and
41
B. The semi-spherical portion
42
B is provided with a long hole
43
B extending toward the turning center axis. The long hole
43
A functions as a guide hole for the operating member
30
.
The semi-spherical portion
42
B is provided at its lower surface with a recess
46
B into which the disc
33
of the operating member
30
is fitted. The recess
46
B ensures the turning movement of the disc
33
when the operating member
30
is operated toward the long hole
43
B of the turning member
40
B. A pair of recessed bearings
47
B and
47
B are provided in an inner surface of the recess
46
B such as to sandwich the long hole
43
B. The turning shaft
32
of the operating member
30
is fitted to the bearings
47
B and
47
B.
A gear
44
B is integrally formed on a tip end surface of one of the turning shafts
41
B and
41
B. The gear
44
B projects sideway of the body
15
, and is located above the other one of the slider accommodating portions
16
and
16
. The gear
44
B has a fan-like shape whose arc surface is directed downward, and the arc surface is formed with spur wheel teeth
45
B.
The hoisting and lowering slider
50
for resiliently holding the operating member
30
at the neutral position is annular in shape so that the hoisting and lowering slider
50
can vertically movably fitted in the body
15
of the case
10
. The hoisting and lowering slider
50
is disposed below the turning members
40
A and
40
B, and is biased upward by the spring
60
compressed and accommodated between the hoisting and lowering slider
50
and the bottom plate
11
of the case
10
.
The hoisting and lowering slider
50
is biased and resiliently brought into contact with flat a lower surface of the disc
33
of the operating member
30
and flat surfaces formed on the lower surfaces of the turning members
40
A and
40
B, thereby directly holding the operating member
30
and the turning members
40
A and
40
B at the neutral position.
The key top
70
vertically moved by the operating member
30
is inserted into the cylindrical guide
14
formed at the central portion of the bottom plate
11
of the case
10
such as to pass through the bottom plate
11
. With this, a lower end of the key top
70
abuts against the switch body
110
on the board
100
from above, and the switch body
110
resiliently pushes the upper operating member
30
upward through the key top
70
.
As shown in
FIG. 7
, the switch body
110
constituting the pushdown switch together with the key top
70
comprises a stationary contact
111
formed on the board
100
by printing, and a domical movable contact piece
112
secured on the stationary contact
111
. The stationary contact
111
comprises an annular first contact
111
a
and a second contact
111
b
formed inside of the first contact
111
a.
The movable contact piece
112
is made of conductive thin plate, and is secured on the annular first contact
111
a
by pasting a resin sheet
113
on the board
100
from above the movable contact piece.
The straight-ahead sliders
80
and
80
accommodated in the slider accommodating portions
16
and
16
of the case
10
are capable of moving horizontally along a side surface of the body
15
, and the straight-ahead sliders
80
and
80
are prevented from being pulled out downward by means of the side edge of the bottom plate
11
of the lower case
10
a.
Each of the straight-ahead sliders
80
and
80
is provided at its upper portion with a projection
81
projecting upward of the slider accommodating portion
16
through the slit-like opening
18
formed in the upper surface of the slider accommodating portions
16
and
16
. The projection
81
is formed at its upper surface with rack gear teeth
82
in the moving direction of the straight-ahead slider
80
. The teeth
82
meshes with the teeth
45
A and
45
B of the fan-like gears
44
A and
44
B formed on one ends of the turning members
40
A and
40
B.
As shown in
FIG. 5
, a contact
90
is mounted to a lower surface of each of the straight-ahead sliders
80
and
80
. The contact
90
faces a surface of the board
100
through the opening formed in the lower surface of the slider accommodating portion
16
, and is resiliently contacted with a resistance circuit
120
(see
FIG. 6
) formed on the surface of the mounting board
100
.
As shown in
FIG. 6
, the resistance circuits
120
are located below volume portions
20
A and
20
B, and formed on the surface of the mounting board
100
. Each of the resistance circuits
120
includes a carbon resistor
121
and conductive portion
122
arranged straightly at a distance therebetween. The contact
90
includes a pair of contacting portions
91
and
91
arranged straightly so that they come into contact with the carbon resistor
121
and the conductive portion
122
. The carbon resistor
121
and the conductive portion
122
are brought into conduction to constitute the volume.
Next, a function of the multi-directional input apparatus according to the embodiment of the present invention will be explained.
If the operating member
30
is inclined toward the long hole
43
B of the lower turning member
40
B, the upper turning member
40
A is turned. With this movement, the volume portion
20
A is operated, and a resistance value corresponding to the operation amount is obtained. That is, in the volume portion
20
A, the gear
44
A is turned by the turning movement of the turning member
40
A, thereby moving the straight-ahead slider
80
, the contact
90
slides on the corresponding resistance circuit
120
, and a resistance value corresponding to the operation amount is obtained.
If the operating member
30
is inclined toward the long hole
44
A of the upper turning member
40
A, the lower turning member
40
B is turned. With this movement, the volume portion
20
B is operated, and a resistance value corresponding to the operation amount is obtained. That is, in the volume portion
20
B, the gear
44
B is turned by the turning movement of the turning member
40
B, thereby moving the straight-ahead slider
80
, the contact
90
slides on the corresponding resistance circuit
120
, and a resistance value corresponding to the operation amount is obtained.
The operating member
30
is operated in an arbitrary direction by a combination of the above movements, and a signal in accordance with the operation direction and amount is input to electronic equipment which uses the multi-directional input apparatus.
If the operating member
30
is pushed down in the axial direction, the pushdown switch provided below the operating member
30
is operated. That is, if the operating member
30
is pushed down, the switch body
110
on the board
100
is pushed down through the key top
70
, the domical movable contact piece
112
is deformed downward and brought into contact with the second contact
111
b
of the stationary contact
111
, thereby bringing the first contact
111
a
and the second contact
111
b
into conduction.
The pushdown switch comprises the key top
70
in the case
10
, and the switch body
110
provided on the board
100
. That is, only the key top
70
of the pushdown switch is provided in the case
10
, and the switch body
110
is provided on the board
100
below the case
10
. With this structure, when the multi-directional input apparatus is mounted on the board
100
, it is unnecessary to solder the pushdown switch to the board
100
.
Further, the switch body
110
comprises three parts, i.e., the stationary contact
111
, the movable contact piece
112
and the resin sheet
113
. Therefore, the number of parts constituting the pushdown switch can largely be reduced as compared with the number of parts (several) constituting the conventional pushdown switch unit and thus, the cost can be reduced.
The volume portions
20
A and
20
B comprise the slider accommodating portions
16
and
16
provided on the two perpendicular side surfaces of the case
10
, the fan-like gears
44
A and
44
B provided on one ends of the turning members
40
A and
40
B, and the straight-ahead sliders
80
and
80
accommodated in the slider accommodating portions
16
and
16
, and the contacts
90
and
80
mounted to the lower surfaces of the straight-ahead sliders
80
and
80
. Among these constituent parts, the slider accommodating portions
16
and
16
and the gears
44
A and
44
B are integrally formed together with the existing constituent elements of the multi-directional input apparatus. Therefore, the parts required for constitute the volume portions
20
A and
20
B are two parts, i.e., the straight-ahead sliders
80
and
80
and the contacts
90
and
90
.
Therefore, not only the number of parts of the pushdown switch, but also the number of signal output means can largely reduced, and the cost can also be reduced.
Further, like the pushdown switch, when the volume sections
20
A and
20
B as the signal output means are mounted, it is unnecessary to solder the volume sections to the resistance circuits
120
and
120
on the board
100
. That is, when the multi-directional input apparatus is mounted, no soldering operation is required. Therefore, the assembling cost of electronic equipment which uses the multi-directional input apparatus can largely be reduced.
As explained above, according to the multi-directional input apparatus of the present invention, the pushdown switch comprises a combination of the key top which is vertically movably provided below the operating member such as to pass through the bottom plate of the case, and the switch body which is located below the key top and mounted on the board, and which is operated when the operating member is pushed down and the key top is moved down. Therefore, it is unnecessary to solder the pushdown switch to the board at the time of mounting operation. Thus, it is possible to reduce the assembling cost of equipment which uses the multi-directional input apparatus, and to reduce the manufacturing costs of the multi-directional input apparatus.
According to another multi-directional input apparatus of the invention, since the switch body comprises a combination of the stationary contact formed on the board and the domical movable contact piece secured on the stationary contact, the number of parts constituting the switch body can largely be reduced. For this reason also, it is possible to reduce the manufacturing cost of the equipment which uses the multi-directional input apparatus.
According to another multi-directional input apparatus of the invention, the movable contact piece is secured on the stationary contact by pasting the resin sheet on the board from above the movable contact piece. Therefore, the number of manufacturing steps of the switch body can be reduced. For this reason also, it is possible to reduce the manufacturing cost of the equipment which uses the multi-directional input apparatus.
According to another multi-directional input apparatus of the invention, as the signal output means for outputting signal corresponding to the turning angle of the turning member, gears are mounted to one ends of the set of upper and lower turning members in the case secured on the board, the straight-ahead sliders capable of moving along the two side surfaces of the case and the board are mounted below the gears, teeth meshing with the gears are provided on the upper surfaces of the straight-ahead sliders, and the contacts which can slide to come into contact with the resistance circuits to constitute the volumes together with the resistance circuits are mounted on the lower surfaces of the straight-ahead sliders, thereby integrally forming the signal output means with the apparatus. Therefore, it is possible to largely reduce the number of parts of the signal output means, and to further reduce the manufacturing costs of the apparatus. Further, it is unnecessary to solder the signal output means to the board, and it is possible to reduce the assembling cost of the equipment which uses the multi-directional input apparatus.
INDUSTRIAL APPLICABILITY
The present invention can be utilized as an input device of a personal computer, a game machine and the like.
Claims
- 1. A multi-directional input apparatus comprising a case secured on a board; a set of upper and lower turning members supported in said case such that said turning members can turn into two intersecting directions and each having a long hole extending in a direction perpendicular to said turning direction; an operating member which can be pushed down and which passes through each of said long holes of said set of upper and lower turning members, said operating member turning each of said turning members when said operating member is operated in arbitrary direction therearound; a holding mechanism for resiliently holding said operating member or said turning members at a neutral position; a set of signal output means for outputting signal corresponding to a turning angle of each of said turning members; and a pushdown switch which is switched when said operating member is pushed down; whereinsaid pushdown switch comprises a combination of a key top which is vertically movably provided below said operating member such as to pass through a bottom plate of said case, and a switch body which is located below said key top and mounted on said board, and which is operated when said operating member is pushed down and said key top is moved down.
- 2. The multi-directional input apparatus according to claim 1, wherein said switch body comprises a combination of a stationary contact formed on said board and a domical movable contact piece which can be resiliently deformed and secured on said stationary contact.
- 3. The multi-directional input apparatus according to claim 2, wherein said movable contact piece is secured on said stationary contact by pasting a resin sheet on said board from above said movable contact piece.
- 4. The multi-directional input apparatus according to any one of claims 1 to 3, wherein said signal output means is constituted such that gears are mounted to one ends of said set of upper and lower turning members, straight-ahead sliders capable of moving along two side surfaces of said case and said board are mounted below said gears, teeth meshing with said gears are provided on upper surfaces of said straight-ahead sliders, and said contacts which can slide to come into contact with resistance circuits to constitute volumes together with said resistance circuits are mounted on lower surfaces of said straight-ahead sliders.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-260713 |
Sep 1999 |
JP |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/JP00/05360 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO01/20629 |
3/22/2001 |
WO |
A |
US Referenced Citations (5)