JPH0330908Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an X-Y direction input device, and relates to an X-Y direction input device suitable for, for example, a figure input device of a graphic display device.

[Conventional technology]

A graphic display device basically consists of a display screen, a display controller, a data channel, and various input devices. One of these input devices is that when the operator tilts a lever supported by a gimbal mechanism in a desired direction, the direction and angle of tilt are detected, and the voltage of each component in the X-axis direction and Y-axis direction or digital There is a "joystick" (registered trademark) that generates a signal. However, with this input device, the rotation range of the lever is limited and there are also problems with the stability of the input signal.

In order to overcome this drawback, an input device called a "mouse" has been developed in recent years. This input device includes a rotated sphere (hereinafter abbreviated as sphere) made of a rotatably arranged steel ball, for example, and a first driven roller that is in contact with the sphere and rotates by the rotational force of the sphere. , a second driven roller that is in contact with the sphere and rotates by the rotational force of the sphere and whose axial direction is substantially perpendicular to the axial direction of the first driven roller; and a rotation angle of the first and second driven rollers. first and second rotation angle detection means each individually detecting a variable resistor, an encoder, etc., and these spheres, first and second driven rollers, first and second rotation angle detection means, etc. It basically consists of a casing for housing.

An opening is provided in the lower surface of the casing, and a part of the sphere protrudes downward through the opening, and by holding the casing and rolling the sphere in any direction on a predetermined base, the first and second spheres can be moved. The two driven rollers each rotate in a predetermined direction. The rotation direction and rotation angle of these driven rollers are
The second rotation angle detecting means extracts each component in the X-axis direction and Y-axis direction as a voltage or digital signal, and these signals are input to a display device.

As an example of this type of input device,
There is an input device described in Publication No. 83737. This input device was developed primarily for the purpose of providing a position pointing device of the type having a sphere as a moving and controlling device in order to release pressure in any given direction of motion.

[Problem that the invention attempts to solve]

By the way, as mentioned above, in this type of input device, an opening is provided on the lower surface of the casing, a part of the sphere protrudes downward through the opening, and the sphere is rolled on the base by holding the casing. Since the system is set to detect the amount of rolling of the sphere and input the coordinates, if any dust remains on the base, it will enter the casing as the sphere rolls and change the rotation angle inside the casing. There is a risk that it may adhere to the mechanisms and sensors that constitute the detection means. This adhesion may cause malfunction of the mechanism or malfunction of the sensor, making it impossible to perform accurate detection. Further, when the ball passes over foreign objects such as dust, the rotational state of the sphere changes, which not only makes the signal output state unstable but also makes it unfavorable for the operating feel.

On the other hand, the drawing showing the position pointing device described in the above-mentioned Japanese Patent Application Laid-Open No. 51-83737 shows a projection formed in an annular shape on the outer periphery of the lower surface of the housing. It is also believed that it is possible to prevent dust from entering the area.

However, even if a protrusion is formed on the outer periphery of the lower surface of the housing in this way, it is not possible to remove dust that has adhered or remains within the outer periphery when the housing is placed on the base. It will be kept within the periphery. As a result, when the sphere rolls, conversely, dust within the outer periphery may be introduced into the housing through the sphere, or the same foreign matter may be overcome over and over again in different locations.

In addition, a step is formed at the periphery of the opening disclosed in the above publication, and the portion where the step is formed is thinner than other parts, so cracks may occur in the periphery. There is a risk of damage.

This idea was created in view of the technical background described above, and its purpose is to eliminate the risk of damage to the periphery of the opening, and to minimize the introduction of dust into the casing and the frequency of overcoming foreign objects. It is an object of the present invention to provide an X-Y direction input device that can perform accurate detection and has an excellent operating feel.

[Means for solving problems]

In order to achieve the above object, this invention consists of a rotatable sphere arranged to be freely rotatable, and a first rotating sphere that is in contact with the rotated sphere and rotates by the rotational force of the rotated sphere.
a second driven roller that is in contact with the rotated sphere and rotates by the rotational force of the rotated sphere and whose axial direction is substantially orthogonal to the axial direction of the first driven roller; a first rotation angle detection means for detecting the rotation angle of the driven roller; a second rotation angle detection means for detecting the rotation angle of the second driven roller; these rotated spheres, the first and second driven rollers; a casing for accommodating a roller and first and second rotation angle detection means, an opening is formed in the lower part of the casing, a part of the rotated sphere projects downward from the opening, and the rotated sphere is attached to a base. In the X-Y direction input device that rolls on the
The opening is formed at a position closer to one side of the casing, and an annular protrusion protrudes along the lower periphery of the opening, and an annular protrusion is formed at a position closer to the other side of the casing. It is configured to include a protrusion and at least two balance protrusions that protrude by approximately the same amount of protrusion.

[Effect]

According to the above means, since the annular protrusion is provided on the peripheral edge of the opening, which has weak strength, the strength of the peripheral edge of the opening is increased and there is no possibility that the peripheral edge will be damaged. In addition, since the protrusion heights of the annular protrusion and the balance protrusion are set to almost the same level, the annular protrusion comes into sliding contact with the base, and foreign objects on the base are removed by the protrusion. becomes possible. Furthermore, when the input device is placed on the base, the area surrounded by the protrusions is the smallest considering the function of the sphere, and the amount of foreign matter such as dust introduced from the area surrounded by the protrusions is minimized. At the same time, the frequency of climbing over foreign objects can be minimized.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall perspective view of a graphic display device including an X-Y direction input device according to an embodiment.

On the table 1 are a display device 2 having a screen, a controller, a data channel, etc., an input device 3 having function keys, and an input device 4 according to an embodiment of the present invention.
is placed. Note that the input device 4 is operated on a dedicated sheet 5 placed on the table 1,
By this operation, for example, the cursor 7 displayed on the screen 6 of the display device 2 can be moved to an arbitrary position.

Next, the structure and operating principle of this input device 4 will be explained. FIG. 2 is a plan view of the input device 4;
3 is a front view of the input device, FIG. 4 is a rear view of the input device, and FIG. 5 is a cutaway side view of the input device.

The casing 8 consists of a lower case 9 and an upper case 10 molded from hard synthetic resin, and as shown in FIGS. 3 and 4, the lower case end 11 of the upper case 10 touches the upper case end 12 of the lower case 9. It is fitted externally to cover it. This is to prevent dust, water, etc. from entering into the casing 8 from the joint between the lower case 9 and the upper case 10.

The upper case 10 is designed to be large enough for an operator to hold and operate with one hand, and has an upper wall portion 13, a left side, a
The right side wall portions 14, 14 are inclined at an appropriate angle. An operating end 16 of the switch 15 is located at a predetermined position on the upper wall portion 13 of the upper case 10, that is, at a position opposite to the fingers when the upper case 10 is grasped by hand.
A rectangular insertion hole 17 into which the holder is inserted is formed. This switch 15 is a push button type,
As shown in FIG. 2, about two or three switches (indicated by dashed lines) are installed, and in addition to the switch of the input device 4 itself, for example, a part of the display pattern immediately above the cursor 7 on the display device 2 is installed. Used for deletion, movement to another display position, and other controls. As shown in FIGS. 3 to 5, the operating end 16 of the switch 15 slightly protrudes from the upper case 10. As shown in FIGS.

FIG. 6 is a bottom view of the upper case 10, showing the upper wall portion 13.
A cylindrical portion 18 is integrally provided at a predetermined position on the inner surface of the cylindrical portion 18, and a short tubular elastic shock absorber 19 made of synthetic rubber or the like is inserted inside the cylindrical portion 18. Cylinder part 1
The buffer body 19 is fixed within the buffer body 8 by forcibly pushing it in using the elasticity of the buffer body 19, or by using an adhesive or the like. As shown in Figure 5,
In order to perform the function of the buffer body 19, its lower end protrudes slightly lower than the lower end of the cylindrical portion 18.

As shown in FIG. 6, the front wall 20 of the upper case 10
A bushing fitting notch 21 is provided approximately in the center of the bushing, and connecting holes 22, 22 are provided on both sides of the bushing fitting notch 21. Further, a screw insertion portion 25 into which a tapping screw 24 (see FIG. 5) is screwed is integrally provided at the center of the inner surface of the rear wall portion 23 of the upper case 10 in a protruding manner.

FIG. 7 is a plan view of the lower case 9 to which the mounting plate 26 is attached, and FIG. 8 is a bottom view of the lower case 9. A bushing fitting notch 28 is formed approximately in the center of the front wall 27 of the lower case 9, and connecting pawls 29, 29 are provided on both sides of the notch 28 to project forward.
A screw insertion portion 32 having an insertion hole 31 is integrally provided at the center of the inner surface of the rear wall portion 30 of the lower case 9 . As shown in FIG. 7, a mounting plate 26 made of metal or hard synthetic resin is connected with screws 33 on top of the lower case 9 with a slight gap between them. In addition to being used for attachment, it also serves as a reinforcing member for the lower case 9. Further, a plurality of pillars 34 (three in this embodiment) are integrally erected from the lower case 9, and a conductive pattern (not shown) of a predetermined shape is formed on the upper part of the pillars 34 as shown in FIG. A printed circuit board 35 is attached with screws. In this embodiment, one support column 34 extends upward through the mounting plate 26, as shown in FIG.

The lower case 9 and the upper case 10 are joined by fitting the connecting claws 29, 29 of the lower case 9 into the connecting holes 22, 22 of the upper case 10, respectively, as shown in FIG.
As shown in FIG. 5, this is done by screwing the tapping 24 into the screw insertion portion 25 of the upper case 10 from the lower case 9 side. When joining the lower case 9 and the upper case 10, a rubber bushing 36 is fitted between the bushing fitting notches 21 and 28, and is clamped between the lower case 9 and the upper case 10. The bushing 36 is for protecting the signal line 37, one end of the signal line 37 is connected to the printed circuit board 35 as shown in FIG. 5, and the other end is the input of the display device 2 as shown in FIG. connected to the end. This signal line 37 has a length that does not interfere with operating the input device 4 on the seat 5.

As shown in FIG. 7, a circular opening 38 is formed at a predetermined position in the lower case 9, and the mounting plate 26
A through hole 39 having a slightly larger diameter than the opening 38 is provided at a position facing the opening 38 . 9th
The figure is an enlarged sectional view taken along the line of FIG. As shown in this figure, the peripheral edge of the opening 38 is tapered 4 so that the diameter becomes slightly smaller toward the bottom.
0, and an annular first jetty 41 is provided at the lower peripheral edge of the opening 38 so as to surround the opening 38. Another annular second jetty 42 is provided at a predetermined interval on the outside of the first jetty 41 in the radial direction.
2 protrudes integrally from the lower case 9, and both have approximately the same height.

As shown in FIG. 8, the first jetty 41 and the second
Since the jetty 42 is offset toward the rear of the lower case 9, correspondingly, balancing projections 43 are provided on both sides of the front. In this example, there are three points: a sphere 44, which will be described later, partially protruding from the opening 38 of the lower case 9, protrusions 43, 43 on both sides, and a first
The jetty and the second jetty are in contact with the base.

A sphere 44 made of a steel ball and having a predetermined weight is arranged above the opening 38 formed in the lower case 9, and a part of the sphere 44 protrudes downward from the opening 38 to attach to the base (seat 5 or other surface) so that it rolls on top of the surface.

FIG. 10 is an enlarged plan view of the operating section during assembly of the input device. The spherical surface of the sphere 44 has a first
The driven roller 45 and the second driven roller 46 are in contact with each other, and both rollers 45 and 46 are each mounted on a bearing 47.
It is rotatably attached to the mounting plate 26 via. In this example, although not shown, each bearing 47 is screwed to the mounting plate 26. The first driven roller 45 and the second driven roller 46 are
It is molded from polyacetal resin mixed with glass fiber in a predetermined proportion. On the other hand, the bearing 47 is made of, for example, fluororesin or polyacetal resin, which has a small coefficient of friction.

As shown in FIG. 10, when the operating section is viewed from above, the first driven roller 45 and the second driven roller 46 are arranged so that their axial directions are perpendicular to each other, and both rollers 45 and 46 are rotated by the rotation of the sphere 44. Each is rotated individually by a force. The rotation direction and rotation angle of the first driven roller 45 are detected by a first variable resistor 49 connected via a rotation shaft 48. On the other hand, the rotation direction and rotation angle of the second driven roller 46 are as follows:
It is detected by the second variable resistor 51 connected via the rotating shaft 50. That is, as shown in FIG. 11, changes in the rotation direction and rotation angle of the first driven roller 45 appear as the slide direction and the amount of movement of the slider 52 in the first variable resistor 49. Similarly, changes in the rotational direction, rotational direction, and rotational angle of the second driven roller 46 appear as the sliding direction and the amount of movement of the slider 53 in the second variable resistor 51. Therefore, the rotation state of the sphere 44 is x
It can be divided into each component in the axial direction and the y-axis direction and detected as the respective voltage values of the first variable resistor 49 and the second variable resistor 51. For this reason, the variable resistors 49 and 51 need to be able to respond appropriately even to small torques.

The terminal group 54 of the first variable resistor 49 and the second
The terminal group 55 of the variable resistor 51 extends upward and is connected to the printed circuit board 35, respectively.

FIG. 12 shows a sphere 44 and driven rollers 45, 46.
FIG. 4 is an explanatory diagram showing the respective arrangement states of the elastic urging rollers 56 and 56. FIG. As shown in FIG. 1 and FIG. 10, the elastic biasing roller 56 is placed in contact with the sphere 44 and facing the first driven roller 45 and the second driven roller 46 via the sphere 44. This elastic biasing roller 56 is provided to ensure power transmission between the sphere 44 and the first driven roller 45 as well as between the sphere 44 and the second driven roller 46. The biasing roller 56 is freely rotated by the rotational force of the sphere 44 and elastically urges the sphere 44 toward the first driven roller 45 and the second driven roller 46 side.

As shown in FIG. 12, the sphere 44 and the first driven roller 45 are arranged so that the contact pressure between the sphere 44 and the first driven roller 45 is equal to the contact pressure between the sphere 44 and the second driven roller 46.
A straight line Q connecting the contact point P of the elastic urging roller 56 of No. 4 and the rotation center O of the sphere 44 is the first driven roller 45.
The elastic biasing roller 56 is arranged so as to pass through the center point between the second driven roller 46 and the second driven roller 46, that is, Θ ₁ =Θ ₂ .

After the first driven roller 45, the second driven roller 46, the first variable resistor 49, the second variable resistor 51, and the elastic biasing roller 56 are attached to the mounting plate 26, the mounting plate 26 is attached to the lower case 9. It is designed to be fixed to the inner surface of the

In addition to metals such as steel balls, glass and synthetic resin are also conceivable materials for the sphere 44, but since these materials alone have a lower specific gravity than metal, they do not provide sufficient frictional force with the base and may not slip. I can't get a proper input signal. For these reasons, the metal sphere 44 is preferable, but it is also necessary to control the roughness of the sphere within a predetermined range.

FIG. 13 is a side view of the driven rollers 45, 46, and FIG. 14 is a cutaway front view thereof. The first and second driven rollers 45 and 46 are both molded from synthetic resin mixed with a fiber reinforcing material such as glass fiber, and have an inner cylindrical portion 61 having an oval-shaped through hole 60 through which the rotating shafts 48 and 50 are inserted. and an outer cylindrical portion 6 provided at a predetermined interval radially outward from the cylindrical portion 6.
2, a plurality of connecting parts 63 extending radially from the inner circumferential cylinder part 61 toward the outer circumferential cylinder part 62, and the inner circumferential cylinder part 61.
and an end face portion 64 connecting one end portion of the outer circumferential tube portion 62 to one end portion of the outer circumferential cylinder portion 62. The inner cylindrical part 61, the outer cylindrical part 62, the connecting part 63, and the end surface part 64 have approximately the same wall thickness, and the inner cylindrical part 61 and the outer cylindrical part 62 are separated by the connecting part 63. A plurality of arcuate recesses 65 are formed.

The driven rollers 45 and 46 having such a configuration
Since the ball 44 is lightweight, almost no internal distortion occurs due to molding, and roundness is obtained, power transmission from the sphere 44 is properly performed.

FIG. 15 is a diagram showing a modification of the driven rollers 45, 46, in which minute irregularities are formed on the outer surfaces in contact with the spherical body 44 to prevent slipping between the rollers and the spherical body 44.

FIG. 16 is a partial front view of the rotating shafts 48, 50 that support the driven rollers 45, 46. Rotating axis 4
Two flat portions 66 facing each other are provided on the outer periphery of the portions supporting the driven rollers 45 and 46 of 8 and 50, thereby forming an oval cross-sectional shape. Driven rollers 45, 46 on the outer peripheries forming flat portions 66 of rotating shafts 48, 50 as shown by dashed lines
is fitted, and a retaining washer 67 is attached to the rotating shafts 48, 50.
The distance L ₁ between the roller 7 and the other end of the flat portion 66 is designed to be slightly longer than the roller width L ₂ of the driven rollers 45 and 46 . Therefore, the driven rollers 45 and 46
It is designed to be able to move along the axial direction of the rotating shafts 48 and 50 by the difference between L ₁ and L ₂ , and when the sphere 44 moves somewhat in the horizontal direction during operation of the input device 4, the driven roller 45 and 46 are now able to follow it.

17 is a side view of the elastic biasing means 68 including the elastic biasing roller 56, FIG. 18 is a rear view of the elastic biasing means 68, and FIG. 19 is a wire spring 69 used in the elastic biasing means 68. FIG.

The elastic biasing means 68 includes an elastic biasing roller 56 made of synthetic resin or hard rubber, a support shaft 70 that rotatably supports the elastic bias roller 56, and a support shaft 70 that rotatably supports the elastic bias roller 56.
A support stand 71 that slidably supports both ends of the
and a wire spring 69 for elastically urging the elastic urging roller 56 toward the sphere 44. As shown in FIG. 18, movement preventing portions 72 are provided at both ends of the support shaft 70 to prevent the wire spring 69 from moving in the axial direction and coming off.
On the support base 71, support protrusions 73, 73 that respectively support both ends of the support shaft 70 are erected at a predetermined interval, and a cut groove 74 is cut in the upper part of the support protrusions 73 toward the sphere 44 side. are respectively formed, and both ends of the support shaft 70 are slidably inserted into the cut grooves 74, and the elastic biasing roller 56 supported by the support shaft 70 is rotatable between the support protrusions 73, 73. inserted into.

As shown in FIG. 19, the wire spring 69 has two base end portions 75 extending in the horizontal direction, and two base end portions 75 extending in the horizontal direction.
It is composed of two pressing parts 76 that stand diagonally upward from one end, and these base end part 75 and pressing part 76 can be easily formed integrally by bending a single spring wire. . As shown in FIGS. 17 and 18, the base end 75 is attached to the support base 71.
The wire spring 69 is positioned by being inserted from both sides of the support shaft 70, while the pressing portions 76 are brought into elastic contact with both ends of the support shaft 70, respectively. Due to this elastic contact, the elastic biasing roller 5
6 is in elastic contact with the sphere 44, and the sphere 44 is further in contact with the first
And the second driven rollers 45 and 46 are brought into even elastic contact, so that desired contact pressures are obtained between the sphere 44 and the first driven roller 45 and between the sphere 44 and the second driven roller 46.

In order to efficiently make elastic contact between the sphere 44 and the first and second driven rollers 45 and 46 by the elastic biasing means 68, as shown in FIG. The contact point R with the roller 45, the contact point S between the sphere 44 and the second driven roller 46, and the contact point P between the sphere 44 and the elastic biasing roller 56 are designed to be on the same plane.

As mentioned above, the sphere 44 is located in the opening 3 of the lower case 9.
8, the sphere 44 moves up and down while the input device 4 is being handled, and therefore the sphere 44 moves around the opening edge of the opening 38 of the lower case 9 or the through hole of the mounting plate 26. The ball 44 may collide with the opening edge of the ball 39, causing noise or damage to the ball 44.

To solve this problem, as shown in FIG. 20, an elastic spherical protection member 77 is disposed near the inner edge of the opening 38 in the lower case 9. The spherical protection member 77 is made of synthetic rubber or soft synthetic resin, and has an annular shape surrounding the edge of the opening 38 . The sphere protection member 77 may be fixed by being clamped between the lower case 9 and the mounting plate 26 as shown in this example, or by being glued to the lower case 9 or the mounting plate 26. By arranging the elastic spherical protection member 77 near the opening 38 in this way, the above-mentioned problem can be solved by its cushioning effect. Furthermore, when an annular spherical protection member 77 is used,
The gap between the opening 38 and the sphere 44 is almost eliminated, preventing dust from entering into the casing 8 through the gap, and all the various troubles caused by the intrusion of dust can be solved.

In the embodiment described above, the rotation angle of the driven roller is detected by a variable resistor, but an encoder or the like may be used instead.

As described above, according to the above embodiment, since the annular protrusion is provided along the periphery of the opening on the lower surface of the casing, even if there is foreign matter such as paper waste, thread waste, or other small pieces on the base, Since foreign objects are pushed aside by the projections when the input device is operated, the rotated sphere does not climb over the foreign objects, and the signal output state is always stable and the operation feeling is good. Become.

In addition, since the area surrounded by the protrusion is set to the minimum functionally, the area surrounded by the protrusion is also minimized when the casing is placed on the base, which reduces the possibility of foreign objects entering the casing. This can prevent malfunctions and errors caused by foreign objects.

Furthermore, as described in the embodiment, the protrusion is formed in an annular shape surrounding the opening of the casing, and its tip makes surface sliding contact with the base.
No matter which direction the input device is operated, the foreign object removal function can be reliably performed. Furthermore, if a plurality of the protrusions are formed in an annular shape so as to surround the opening, the foreign matter removal function will be more reliable.

In addition, since the protrusion is integrally formed with the casing at the lower periphery of the opening, it serves to reinforce the casing, particularly the periphery of the opening where the heavy rotating sphere is placed nearby.

[Effect of idea]

According to this invention, an annular protrusion is attached along the periphery of the opening on the lower surface of the casing, and a balancing protrusion with approximately the same protrusion height as the annular protrusion is provided at a position that balances the annular protrusion. Since the peripheral edge of will be reinforced by the protrusion,
There is no risk of damage to the peripheral edge of the opening, and since the tip of the annular protrusion comes into contact with the base over almost the entire circumference, the possibility of foreign matter being introduced into the casing can be minimized. can. It is possible to provide an X-Y direction input device that is highly accurate, has an excellent operational feel, and is highly reliable.

[Brief explanation of the drawing]

The figures are all for explaining the X-Y direction input device according to the embodiment of the present invention, and FIG. 1 is a perspective view of a graphic display device including the input device, and FIG. 2 is a plan view of the input device. Figure 3 is a front view of the input device, Figure 4 is a rear view of the input device, Figure 5 is a cutaway side view of the input device, Figure 6 is a bottom view of the upper case, and Figure 7 shows the mounting plate. A plan view of the attached lower case, Figure 8 is a bottom view of the lower case, and Figure 9 is a bottom view of the lower case.
The figures are Fig. 8 - an enlarged sectional view on the line, Fig. 10 is an enlarged plan view of the actuating part of the input device, Fig. 11 is a principle diagram of the actuating part, and Fig. 12 is the arrangement of the sphere, driven roller, and urging roller. An explanatory diagram showing the state, FIG. 13 is a side view of the driven roller, FIG. 14 is a cutaway front view of the driven roller, FIG. 15 is a front view showing a modified example of the driven roller, and FIG. 16 is a part of the rotating shaft. A front view, FIG. 17 is a side view of the elastic biasing means, FIG. 18 is a rear view of the elastic biasing means, FIG. 19 is a perspective view of the wire spring used in the elastic biasing means, and FIG. 20 is a sphere protection FIG. 3 is a sectional view of a main part showing a state in which the member is attached. 4...Input device, 5...Seat, 8...Casing, 9...Lower case, 10...Upper case, 38
... opening, 41 ... first jetty, 42 ... second jetty, 44 ... sphere, 45 ... first driven roller, 4
6... Second driven roller, 49... First variable resistor, 51... Second variable resistor.

Claims (1)

[Scope of utility model registration request] A first driven roller that is in contact with the rotated sphere and rotates by the rotational force of the rotated sphere, and a first driven roller that is in contact with the rotated sphere and rotates by the rotational force of the rotated sphere. a second driven roller whose axial direction is substantially orthogonal to the axial direction of the first driven roller; a first rotation angle detection means for detecting a rotation angle of the first driven roller; A casing that houses the rotated spheres, the first and second driven rollers, and the first and second rotation angle detection means. , an X-Y direction input device in which an opening is formed in the lower part of the casing, a part of the rotated sphere is made to protrude downward from the opening, and the rotated sphere is caused to roll on a base; an annular protrusion formed at a position closer to the side and protruding along the lower periphery of the opening; and a protrusion substantially identical to the annular protrusion at a position closer to the other side of the casing. An X-Y direction input device comprising at least two protrusions for balance that protrude by a certain amount.