X-Y direction input device

Disclosed is an X-Y direction input device which requires a smaller number of parts and is less costly. Frictional force applying means comprises a rolling contact roller held in rolling contact with a rotated spherical body, a resilient member inserted in a through hole formed at the axial center of the rolling contact roller, and support members holding both ends of the resilient member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an X-Y direction input device, and more 
particularly to an X-Y direction input device called a mouse (trade name). 
2. Description of the Related Art 
A computer system is basically made up of a display screen, a display 
controller, data, various input devices and so on. 
There are known various forms of input devices up to now. As one of those 
input devices, an X-Y direction input device called a "mouse" (trade name) 
has been developed in which when a case is moved on a base in any desired 
direction, the direction and amount of movement of the case is detected. 
Such an X-Y direction input device is basically made up of a rotated 
spherical body (referred to simply as a spherical body hereinafter) formed 
of a steel ball, for example, a first driven roller contacting the 
spherical body to be rotatable by rotating force of the spherical body, a 
second driven roller contacting the spherical body to be rotatable by 
rotating force of the spherical body and having an axis substantially 
perpendicular to the axis of the first driven roller, first and second 
rotational amount detecting means formed by rotary electrical parts, such 
as variable resistors or encoders, for individually detecting respective 
amounts of rotation of the first and second driven rollers, and a case for 
housing the spherical body, the first and second driven rollers, and the 
first and second rotational amount detecting means. 
An opening is formed in a lower wall of the case so that part of the 
spherical body projects downward through the opening. When an operator 
holds the case by the hand and rolls it on a predetermined base in any 
desired direction, the first and second driven rollers rotate respectively 
in the predetermined directions. The first and second rotational amount 
detecting means take out the directions and amounts of rotation of the 
driven rollers in the form of voltage or digital signals indicating 
components of the rotation in the X-axis and Y-axis directions. These 
signals are input to a display device of the computer system. 
In the X-Y direction input device thus constructed, frictional force 
applying means is required to resiliently urge the spherical body toward 
the first driven roller and the second driven roller under even forces for 
applying frictional forces between the spherical body and both the driven 
rollers. 
A typical example of conventional frictional force applying means will be 
described with reference to FIGS. 13 and 14. 
The conventional frictional force applying means comprises a rolling 
contact roller 57' of synthetic resin, a roller support member 58' for 
supporting the rolling contact roller 57', a container 17' for supporting 
the roller support member 58', and a coil spring 59'. 
The roller support member 58' formed of a molding of synthetic resin has a 
pair of rotary support shafts 58'a provided on its upper side walls, and a 
spring receiving projection 58'b (see FIG. 14) provided on its lower back 
surface. Further, a bearing portion 58'c is formed to be open forward in a 
middle position between the rotary support shafts 58'a and the spring 
receiving projection 58'b. Both ends of a support shaft 60' inserted 
through the rolling contact roller 57' is press-fitted to the bearing 
portion 58'c so that the rolling contact roller 57' is rotatably supported 
by the roller support member 58' with the support shaft 60' serving as a 
rotary shaft. 
The roller support member 58' thus constructed is inserted into an open 
room 17'a of the container 17' in such a state that the coil spring 59' is 
fitted at its one end over the spring receiving projection 58'b. With the 
insertion of the roller support member 58', as shown in FIG. 14, the 
rotary support shafts 58'a of the roller support member 58' enter cutout 
portions 17'b in opposite walls of the container 17', whereby the coil 
spring 59' is held in a compressed state between the roller support member 
58' and an inner wall of the container 17'. The resulting resilient force 
of the coil spring 59' urges the roller support member 58' to rotate 
clockwise, as viewed on the drawing, about the rotary support shafts 58'a 
as fulcra. By virtue of the biasing force, part of the rolling contact 
roller 57' supported by the roller support member 58' slightly projects 
out of the container 17' toward the opening where the spherical body is 
placed, and an outer wall of the roller support member 58' comes into 
abutment with an inner wall of the container 17'. The roller support 
member 58' and the rolling contact roller 57' are thereby prevented from 
displacing. 
With the above conventional structure, the spherical body can be pressed 
upon both the driven rollers under even forces by arranging the rolling 
contact roller and the coil spring on a straight line connecting a point 
where the axes of the first and second driven rollers cross each other and 
the center of the spherical body. 
The conventional frictional force applying means, however, requires a large 
number of parts and is costly because it is made up of four independent 
components; i.e., the rolling contact roller 57' of synthetic resin, the 
roller support member 58' for supporting the rolling contact roller 57', 
the container 17' for supporting the roller support member 58', and the 
coil spring 59'. Another problem is that the roller support member 58' is 
less cost effective in manufacture and machining because of its 
complicated configuration. 
SUMMARY OF THE INVENTION 
An X-Y direction input device of the present invention comprises a rotated 
spherical body arranged in a rotatable manner, a first driven roller 
contacting the rotated spherical body to be rotatable by rotating force of 
the rotated spherical body, a second driven roller contacting the rotated 
spherical body to be rotatable by rotating force of the rotated spherical 
body and having an axis substantially perpendicular to the axis of the 
first driven roller, first rotational amount detecting means for detecting 
an amount of rotation of the first driven roller, second rotational amount 
detecting means for detecting an amount of rotation of the second driven 
roller, and frictional force applying means for resiliently urging the 
rotated spherical body toward the first driven roller and the second 
driven roller, thereby applying frictional forces between the rotated 
spherical body and both the driven rollers, the frictional force applying 
means comprising a rolling contact roller held in rolling contact with the 
rotated spherical body, a resilient member inserted in a through hole 
formed at the axial center of the rolling contact roller, and support 
members holding both ends of the resilient member. 
In the X-Y direction input device of the present invention, preferably, the 
resilient member is a coil spring, both ends of the coil spring being 
attached to the support members which are provided on the side nearer to 
the rotated spherical body than the axial center of the rolling contact 
roller. 
In the X-Y direction input device of the present invention, preferably, the 
coil spring is wound such that a central portion is a fine-pitch spring 
and both end portions are coarse-pitch springs.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
An X-Y direction input device according to one embodiment of the present 
invention will be described hereunder with reference to the drawings. 
FIG. 2 is a perspective view of an entire computer system including the X-Y 
direction input device. 
In FIG. 2, on a table 1, there are placed a display device 2 including a 
screen 6, a controller and a data channel, an input device 3 having 
function keys, etc., and an input device 4 for moving a cursor in X-Y 
directions and entering an instruction. The input device 4 is operated on 
a specific sheet 5 laid on the table 1, whereupon a cursor 7 indicated on 
the screen 6 of the display device 2, for example, can be moved to a 
desired position. 
FIG. 3 is an exploded perspective view of primary components of the input 
device 4, and FIGS. 4-6 are views for explaining the primary components of 
the input device 4 in which; FIG. 4 is a bottom view of an upper case, 
FIG. 5 is a plan view of a lower case, and FIG. 6 is a plan view of a 
detecting unit. 
As shown in these drawings, a case 8 forming an outer shell of the input 
device 4 comprises a lower case 9 and an upper case 10 which are formed 
of, e.g., an ABS resin. The lower and upper cases 9, 10 are joined by 
screws, not shown, into a one-piece structure. 
Centrally of the lower case 9 in its rear portion (on the left side in FIG. 
5), a large-diameter opening 11 is bored and a peripheral wall 12 is 
erected along a peripheral edge of the opening 11. Also, around the 
opening 11, there are erected two bearing retainers 13, 14 having recessed 
slots 13a, 14a formed therein, and two holder retainers 15, 16 being a 
little larger than the bearing retainers 13, 14. The bearing retainers 13, 
14 and the holder retainers 15, 16 serve to hold and position driven 
rollers and rotational amount detecting means described later. One 13 of 
the bearing retainers and one 15 of the holder retainers cooperate as one 
pair, while the other bearing retainer 14 and the other holder retainer 15 
cooperate as the other pair. These two pairs of retainers are disposed 
such that their center lines (axes) cross each other perpendicularly. 
A spherical body 63 is placed in the opening 11 of the lower case 9 and 
held by a lid member 64 not to displace from the opening 11. 
Near the peripheral wall 12, a container 17 having an open room 17a formed 
therein is provided integrally with the lower case 9. The container 17 
serves to contain and hold frictional force applying means described 
later. A pair of posts 60, 60 are erected near the container 17 integrally 
with the lower case 9. 
On the lower case 9, there are further erected a pair of elastic 
projections 18, 18 near the holder retainer 15 and the container 17, 
respectively, and three support projections 19 near the elastic 
projections 18, 18. The elastic projections 18, 18 serve to position a 
switch board, described later, relative to the lower case 9 and the 
support projections 19 serve to support the switch board. Additionally, 
screw insertion holes 20, 21, 22, 23 are bored through the lower case 9 in 
two front positions and two rear positions. 
The upper case 10 is designed to have such a size as allowing an operator 
to operate the device while holding it by one hand. A pair of fitting 
holes 24 are formed in a curved upper wall portion of the upper case 10 on 
the front side. As is apparent from FIG. 4, a plurality of fusible pins 25 
are vertically provided on an inner surface of the upper wall portion of 
the upper case 10. Two switch levers 26 are joined to each other at one 
ends thereof and fixed to the upper case 10 by the fusible pins 25. This 
fixation is carried out by fitting small holes formed in the switch levers 
26 through the fusible pins 25 and then fusing tips of the fusible pins 25 
to fix the switch levers 26 in place by caulking. Thus, the switch levers 
26 are angularly movable by virtue of their own resiliency about the 
caulked ends as fulcra. In a state after being fixed to the upper case 10, 
operating ends of the switch levers 26 are positioned to slightly project 
out of the respective fitting holes 24. 
In and on the inner surface of the upper wall portion of the upper case 10, 
there are also formed screw insertion holes 27, 28, 29, 30 in positions 
corresponding to the insertion holes 20, 21, 22, 23 of the lower case 9, 
an annular rib 31 in a position corresponding to the opening 11, a 
pressing projection 32 in a position corresponding to the container 17, 
tubular projections 33 in positions corresponding to the elastic 
projections 18, and a pair of pressing ribs 34 in positions near the 
tubular projections 33. Further, from the inner surface of the upper wall 
portion of the upper case 10, there is projected an L-shaped pressing wall 
35 in a position corresponding to the bearing retainers 13, 14 and the 
holder retainers 15, 16, i.e., extending along the center line of one pair 
of the bearing retainer 13 and the holder retainer 15 and the center line 
of the other pair of the bearing retainer 14 and the holder retainer 16. 
Primary components of the detecting unit shown in FIG. 6 are accommodated 
between the lower case 9 and the upper case 10. Referring to FIG. 6, a 
switch board 36 made of relatively hard insulating materials, e.g., a 
phenol resin, has two positioning holes 36a bored therein corresponding to 
the elastic projections 18 of the lower case 9. Two push switches 37 and a 
connector 38 are fixedly soldered onto the switch board 36 and connected 
to each other by pattern wiring (not shown) formed on a rear surface of 
the switch board 36. 
The push switches 37 are switches of the input device 4 itself, and are 
used to carry out processing of various signals indicating, e.g., omission 
of part of a pattern displayed just above the cursor 7 in the display 
device 2, copying of the part to a different display position, and other 
switchover and control operations. The display device 2 and the input 
device 4 are interconnected by a cord 39 and a socket plug 40, as shown in 
FIG. 2. 
A flexible film board 43 having a desired pattern wiring formed thereon and 
partly bent is soldered to each of the switch board 36 and first and 
second encoders 41, 42 as the frictional force applying means. Further, 
first and second driven rollers 44, 45 are coupled respectively to the 
first and second encoders 41, 42. 
Metal bearings 61, 62 are fixed to respective one ends of the first and 
second driven rollers 44, 45. 
As is apparent from the above description, therefore, the first and second 
driven rollers 44, 45, the first and second encoders 41, 42 coupled 
respectively to the rollers 44, 45, and the switch board 36 including the 
push switches 37, the connector 38, etc. mounted thereon are not only 
constructed into a one-piece unit, but also electrically connected to each 
other beforehand through the flexible film board 43. 
FIGS. 7 and 8 are explanatory views of an internal structure of the first 
encoder 41 in which; FIG. 7 is an exploded perspective view and FIG. 8 is 
a sectional view in an assembled state. 
As shown in these drawings, the first encoder 41 comprises a holder 46 
forming an outer shell of the encoder, three sliders 47a, 47b, 47c, a cord 
plate 48 having a common pattern 48a at the center, an inner peripheral 
pattern 48b around the common pattern 48a and an outer peripheral pattern 
48c around the inner peripheral pattern 48b, a tubular spacer 49, and a 
lock nut 50. 
The holder 46 includes a flat portion 51, an annular peripheral wall 52 
formed on one side of the flat portion 51, and a cylindrical bearing 
portion 53 formed on the other side of the flat portion 51. The bearing 
portion 53 is partly projected in vertically opposite positions on its 
peripheral surface, respectively, into a projection 53a and a positioning 
projection 53b. The bearing portion 53 is formed at the center of the 
peripheral wall 52 and has a stepped insertion hole 54 formed therethrough 
for insertion of an inserted shaft portion 44b described later. 
A plurality of fusible pins 51a are erected on the flat portion 51 in an 
area away from the peripheral wall 52, and the sliders 47a, 47b, 47c are 
fixed at their one ends to the flat portion 51 by the fusible pins 51a. 
Opposite free ends of the sliders 47a, 47b, 47c thus fixed at their one 
ends by the fusible pins 51a project into the interior of the peripheral 
wall 52 through a cutout formed in part of the peripheral wall 52. 
On the other hand, at one end of the first driven roller 44, there are 
formed an engagement shaft portion 44a being slightly smaller in diameter 
than a main shaft portion thereof, and an inserted shaft portion 44b being 
even smaller in diameter than the engagement shaft portion 44a. The 
engagement shaft portion 44a and the inserted shaft portion 44b are 
inserted into the insertion hole 54 from the side of the bearing portion 
53. The spacer 49 and the cord plate 48 are successively fitted over the 
inserted shaft portion 44b of the first driven roller 44 which has been 
inserted through the insertion hole 54 and has reached the interior of the 
peripheral wall 52. After that, the lock nut 50 is fitted over a tip end 
of the inserted shaft portion 44b, thereby fixing the cord plate 48 to the 
first driven roller 44. At this time, a step of the first driven roller 44 
between the main shaft portion and the engagement shaft portion 44a comes 
into abutment with a peripheral edge of the insertion hole 54, while one 
end of the spacer 49 comes into abutment with a step on an inner wall of 
the insertion hole 54. The first driven roller 44 is therefore coupled to 
the first encoder 41 in such a state that its axial movement is 
restricted. Also, the cord plate 48 is fixed to the first driven roller 44 
in such a state that the distance from the flat portion 51 is restricted 
by the spacer 49. 
By assembling the first driven roller 44 and the cord plate 48 to the 
holder 46 in such a way, the first, second and third sliders 47a, 47b, 47c 
come into resilient contact with the common pattern 48a, the inner 
peripheral pattern 48b and the outer peripheral pattern 48c, respectively. 
Because the sliders 47a, 47b, 47c are supported at their fulcra away from 
the cord plate 48, as stated above, the span from the resilient contact 
points of the sliders with the cord plate 48 to the fulcra can be set to 
be so long that stable sliding torque is obtained. 
The first encoder 41 is structured as explained above and the second 
encoder 42 has the same structure as the first encoder 41. More 
specifically, the second encoder 42 basically comprises a holder 55 (see 
FIGS. 3 and 6) forming an outer shell of the encoder, three sliders 
supported by the holder 55, and a cord plate held in contact with the 
sliders. The cord plate is fixed to one end of the second driven roller 
45. A bearing portion 56 is projected on one side of the holder 55, and 
has a projection 56a formed at the top thereof and a positioning 
projection (not shown) at the bottom thereof. 
Note that the rotational amount detecting means is described as being of 
contact type comprising the first and second encoders 41, 42 and the 
sliders, the present invention is not limited to the illustrated 
embodiment and the rotational amount detecting means may be of optical 
type comprising photodiodes and encoders. 
The frictional force applying means will now be described by primarily 
referring to FIG. 1. 
As shown in FIG. 1, the frictional force applying means comprises a rolling 
contact roller 57 of synthetic resin, the aforesaid container 17 for 
receiving part of the rolling contact roller 57, a coil spring 59 as a 
resilient member, and a pair of posts 60, 60 as hold members for holding 
both ends of the coil spring 59. 
A through hole 57a is formed at the axial center of the rolling contact 
roller 57. The coil spring 59 is disposed to penetrate the through hole 
57a and has both ends 59a, 59a caught by upper ends of the pair of posts 
60, 60 each having a columnar shape. The rolling contact roller 57 is 
thereby held rotatably while being urged by the coil spring 59. 
The container 17 is formed integrally with the lower case 9 and has a side 
wall projecting upward from the lower case 9 and being channel-shaped in 
horizontal section. The open room 17a is defined inside the channel-shaped 
side wall 17b. 
Part of the rolling contact roller 57 through which the coil spring 59 is 
inserted is received in the open room 17a of the container 17 in a 
floating condition. The rolling contact roller 57 is restricted by the 
side wall 17b in its position in the right and left direction so as to 
locate substantially at the center of the coil spring 59. The posts 60 are 
provided integrally with the lower case 9 to project upward from the lower 
case 9, and are positioned on the side nearer to the spherical body 63 
than the axial center of the rolling contact roller 57. 
Accordingly, the coil spring 59 held by the posts 60 urges the rolling 
contact roller 57 toward the side of the spherical body 63, causing part 
of the rolling contact roller 57 to project into the peripheral wall 12 
through a cut slot formed in the peripheral wall 12. 
In addition, a cross-shaped auxiliary post 60a is integrally formed around 
each of the columnar posts 60 with a height lower than the central post 
60. 
The coil spring 59 is a spring comprised of windings finely coiled over the 
entire spring with a small pitch. The finely wound spring can be 
manufactured with ease. But the configuration of the coil spring 59 is not 
limited to such a finely wound spring. For example, the coil spring may 
not be finely wound with a small pitch over the entire spring, but wound 
such that a central portion which is inserted in the through hole 57a of 
the rolling contact roller 57 is a fine-pitch spring and both end portions 
are coarse-pitch springs. As an alternative, the coil spring may be a 
spring coarsely wound in its entirety. 
By using the coil spring wound such that the central portion is a 
fine-pitch spring and both the end portions are coarse-pitch springs, the 
resilient urging force imposed upon the spherical body from the rolling 
contact roller by the coil spring can be easily selected to any desired 
value. 
Both the ends 59a, 59a of the coil spring 59 are held against upper end 
surfaces 60a' of the cross-shaped auxiliary posts 60a, and are caught by 
grooves (not shown) formed in the posts 60 to be kept from slipping off 
from the posts. 
With the above structure, the spherical body can be pressed upon both the 
driven rollers under even forces by arranging the rolling contact roller 
on a straight line connecting a point where the axes of the first and 
second driven rollers cross each other and the center of the spherical 
body. 
A method of assembling the input device 4 having the above construction 
will now be described by primarily referring to FIGS. 9 to 11. 
FIG. 9 is a top view of the input device with the upper case 10 removed, 
FIG. 10 is a sectional view of the input device taken in the longitudinal 
direction of the case 8, and FIG. 11 is a sectional view of the input 
device taken in the transverse direction of the case 8. 
First, as shown in FIG. 9, the metal bearings 61, 62 at one ends of the 
first and second driven rollers 44, 45 are engaged respectively in the 
recessed slots 13a, 14a of the bearing retainers 13, 14 erected on the 
lower case 9, and the bearing portions 53, 56 of the first and second 
encoders 41, 42 are engaged respectively in the holder retainers 15, 16. 
At this time, the switch board 36 (see FIG. 36) connected to the first and 
second encoders 41, 42 through the film board 43 is simultaneously placed 
and held on the lower case 9. The first and second encoders 41, 42 are so 
locked as not to rotate because their positioning projections 53b are 
located respectively in the holder retainers 15, 16. 
The first and second driven rollers 44, 45 are thereby disposed on the 
lower case 9 in the predetermined positions such that the roller axes 
cross each other perpendicularly. 
On the other hand, the switch board 36 is positioned on the lower case 9 in 
the predetermined position and rested on the three support projections 19 
by fitting the two positioning holes 36a of the switch board 36 over the 
elastic projections 18 erected on the lower case 9. At this time, since a 
split groove 18a is axially formed at the center of each of the elastic 
projections 18, the switch board 36 can be easily fitted over the elastic 
projections 18 even if the size between the positioning holes 36a of the 
switch board 36 is somewhat varied due to temperature changes and 
machining errors resulted during the boring process. 
The above assembling work of the first and second driven rollers 44, 45, 
the first and second encoders 41, 42 and the switch board 36 onto the 
lower case 9 can be performed in a condition where those components are 
kept together as one unit through the flexible film board 43. Accordingly, 
the components will not separate individually and troublesome soldering 
work after the assembly is no longer required. As a result, the components 
can be very easily assembled. 
Next, an assembly of the rolling contact roller 57 and the coil spring 59 
inserted in the through hole 57a at the axial center of the former is 
placed in the open room 17a of the container 17, and both the ends 59a, 
59a of the coil spring 59 are held respectively by the pair of posts 60, 
60. 
The above assembling work may be performed prior to the assembling work of 
the first and second driven rollers 44, 45. 
After thus assembling the primary components of the detecting unit on the 
lower case 9 in the predetermined positions, the upper case 10 is placed 
over the lower case 9 and screws (not shown) are screwed into the screw 
insertion holes 20, 21, 22, 23 and the screw insertion holes 27, 28, 29, 
30, thereby joining the lower case 9 and the upper case 10 together, as 
shown in FIGS. 10 and 11. 
Joining the lower case 9 and the upper case 10 together results in that, of 
the components of the detecting unit on the lower case 9 in the 
predetermined positions, both the metal bearings 61, 62, the projections 
53a, 56a of the first and second encoders 41, 42, the tops of the 
peripheral walls of the holders 46, 55 are pressed by the pressing wall 35 
projecting down from the upper case 10, whereby the first and second 
driven rollers 44, 45 and the first and second encoders 41, 42 are fixedly 
held between both the cases 9, 10. Further, the tubular projections 33, 
fitted over the elastic projections 18, and the pressing ribs 34 are 
brought at their lower ends into contact with an upper surface of the 
switch board 36. Thus, the switch board 36 is fixedly held in place by the 
tubular projections 33, the pressing ribs 34, and the three support 
projections 19 erected on the lower case 9. 
The two push switches 37 are fixedly soldered onto the upper surface of the 
switch board 36, as described above. On the other hand, the two switch 
levers 26 are fixed at their one ends to the upper wall portion of the 
upper case 10, and actuating members 26a are vertically extended down from 
the underside of the switch levers 26. The actuating members 26a have 
lower end surfaces which are positioned to face the tops of the push 
switches 37 when the lower case 9 and the upper case 10 are joined 
together. Accordingly, when the operator pushes down any of the switch 
levers 26 projecting out of the upper wall portion of the upper case 10, 
the actuating member 26a comes into contact the push switch 37 to effect a 
desired switching operation. 
After joining the lower case 9 and the upper case 10 together as explained 
above, the spherical body 63 which is rotated upon operation of the input 
device and formed of a steel ball is inserted into the case 8 through the 
opening 11 of the lower case 9. Subsequently, the lid member 64 having an 
opening 64a is fixedly fitted to a peripheral edge of the opening 11 of 
the lower case 9. The rotated spherical body 63 is held within the case in 
a rollable manner by the annular rib 31 projecting from the upper case 10 
and an annular retaining portion 64b of the lid member 64 such that a 
lowermost portion of the spherical body 63 is exposed downward through the 
opening 64a of the lid member 64. 
The principle of detecting the amount of rotation in the above embodiment 
will now be explained with reference to FIG. 12. 
The rotated spherical body 63 is held in pressure contact with the first 
and second driven rollers 44, 45 by the rolling contact roller 57. The 
first and second driven rollers 44, 45 have the axes crossing each other 
perpendicularly and come into contact with the rotated spherical body 63 
in orthogonal directions. 
The rolling contact roller 57 is arranged on a straight line connecting a 
point Q where the axes of the first and second driven rollers 44, 45 cross 
each other and the center O of the rotated spherical body 63. Then, the 
resilient urging force of the coil spring 59 causes the rolling contact 
roller 57 to press the rotated spherical body 63 against the first and 
second driven rollers 44, 45 under even forces. 
Further, the first and second encoders 41, 42 are coupled to the ends of 
the first and second driven rollers 44, 45 which serve as rotary shafts 
for the encoders. The first and second encoders 41, 42 detect the amounts 
of rotation of the first and second driven rollers 44, 45, respectively. 
Specifically, the amount of rotation of the rotated spherical body 63 is 
detected by being divided into components in the X- and Y-directions. From 
the detected components, the direction and amount of rotation of the 
rotated spherical body 63 can be determined. 
According to the present invention, as described above, the frictional 
force applying means comprises the rolling contact roller held in rolling 
contact with the rotated spherical body, the resilient member rotatably 
supporting the rolling contact roller, and the support member holding at 
least one end of the resilient member. Accordingly, the frictional force 
applying means of the present invention does not need a part corresponding 
to the roller support member which has been employed in the conventional 
frictional force applying means, and the individual parts are simple in 
configuration. It is thus possible to provide an X-Y direction input 
device which requires the smaller number of parts and is less costly in 
manufacture and machining. 
Also, according to the present invention, the resilient member is a coil 
spring, the coil spring is inserted in the through hole formed at the 
axial center of the rolling contact roller, and both the ends of the coil 
spring are attached to the support members which are provided on the side 
nearer to the rotated spherical body than the axial center of the rolling 
contact roller. This enables the rolling contact roller to be brought into 
rolling contact with the rotated spherical body without strain by the 
resilient urging force of the coil spring. As a result, the rotated 
spherical body can be resiliently urged upon the first and second driven 
rollers under even forces. 
Further, according to the present invention, the coil spring is wound such 
that the central portion is a fine-pitch spring and both the end portions 
are coarse-pitch springs. This provides the following advantages. Since 
the central portion of the coil spring inserted through the axial center 
of the rolling contact roller is wound with a fine pitch, the rolling 
contract roller can roll smoothly. Also, since both the end portions of 
the coil spring is wound with a coarse pitch, the resilient urging force 
imposed upon the spherical body from the rolling contact roller by the 
coil spring can be easily selected to any desired value.