JP7575282B2 - Trackball Device - Google Patents

Description

The present invention relates to a trackball device.

In the trackball device of Patent Document 1 below, a trackball (sphere) is rotatably mounted within a recess in a base (housing). A laser beam generator is provided inside the base, and a circuit board is provided below the recess. A laser generated by the laser beam generator is irradiated toward the trackball and is reflected downward by the outer surface of the trackball. An optical detector provided on the circuit board receives the reflected light and detects the rotation of the trackball.

Here, the area below the recess inside the base is configured as a storage space, and an opening is formed at the bottom of the recess that connects the inside of the recess to the storage space. Therefore, for example, foreign matter such as dust that has entered between the recess and the trackball can be dropped downward through the opening, thereby preventing a decrease in detection performance.

Utility Model Registration No. 3129060

However, in the above trackball device, almost the entire lower part of the recess is open as an opening, so the substrate board can be seen through the opening. This may result in a poor appearance of the trackball device.

In consideration of the above, the present invention aims to provide a trackball device that can suppress deterioration in detection performance while suppressing deterioration in appearance.

One or more embodiments of the present invention are a trackball device that includes a transparent inner case formed in a concave shape that is open to the top, a spherical sphere rotatably housed inside the inner case, a housing that houses the inner case and the sphere and has an exposed portion that operably exposes a portion of the sphere to the outside, a sensor that is provided on the outer periphery of the inner case and is arranged facing the outer surface of the sphere through the inner case and detects the rotation of the sphere, and an exhaust hole that is formed in the bottom wall of the inner case and discharges dust from within the inner case, and an inclined surface is formed on the inner periphery of the exhaust hole, and the inclined surface reduces visibility of the lower area of the bottom wall of the inner case.

One or more embodiments of the present invention are a trackball device in which the ejection hole is formed in a long hole shape, and the inclined surface includes a first inclined surface that is inclined in the vertical direction when viewed from the longitudinal direction of the ejection hole, and a second inclined surface that is arranged parallel to the first inclined surface.

One or more embodiments of the present invention are a trackball device in which, in a plan view, the first inclined surface and the second inclined surface are entirely offset in the short direction of the discharge hole.

One or more embodiments of the present invention are a trackball device in which, in a plan view, a minute gap is formed between the first inclined surface and the second inclined surface, and the distance of the minute gap in the short direction of the discharge hole is set to 1/4 or less of the short-side length of the inner opening of the discharge hole.

One or more embodiments of the present invention are a trackball device in which the inclined surface sets the area of the inner opening of the ejection hole to be larger than the area of the outer opening of the ejection hole.

One or more embodiments of the present invention are a trackball device in which a plurality of the exhaust holes are formed in the bottom wall of the case and are equally spaced apart.

One or more embodiments of the present invention are a trackball device in which a circuit board is provided on the underside of the case, the sensor is disposed on the upper side of the circuit board and connected to the circuit board, an insertion hole is formed in the circuit board through which the bottom of the case is inserted, and the bottom wall of the case is disposed below the circuit board.

According to one or more embodiments of the present invention, it is possible to suppress deterioration in appearance while suppressing deterioration in detection performance.

1 is a perspective view showing a trackball device according to an embodiment of the present invention; 2 is an exploded perspective view showing the trackball device shown in FIG. 1 with the housing removed and with a sensor unit and a sensor holder disassembled from an inner case; FIG. 3 is a longitudinal sectional view of the trackball device shown in FIG. 1 (a sectional view taken along line 3-3 in FIG. 1). 4 is a vertical cross-sectional view of the trackball device shown in FIG. 1 (cross-sectional view taken along line 4-4 in FIG. 1). 2 is a perspective view of one side portion of the trackball device shown in FIG. 1 in a first direction with the housing removed, as viewed from one side in an orthogonal direction. FIG. 6 is a cross-sectional view (cross-sectional view taken along line 6-6 in FIG. 3) showing a state in which the sensor unit shown in FIG. 3 is attached to an inner case. 3A is a perspective view showing the sensor holder shown in FIG. 2 as viewed from the other side in the orthogonal direction, and FIG. 3B is a perspective view showing the sensor holder of FIG. 2 as viewed from one side in the orthogonal direction. 5A is a partially cutaway perspective cross-sectional view showing a modified example of the discharge hole of the inner case shown in FIG. 4, and FIG. 5B is a cross-sectional view of the modified example of the discharge hole of (A) as viewed from the other side in the second direction.

The trackball device 10 according to this embodiment will be described below with reference to the drawings. Note that arrow A, as shown in the drawings, indicates the top of the trackball device 10, and in the following description, when the up and down directions are used, they will refer to the up and down directions of the trackball device 10 unless otherwise specified. In the following description, the direction perpendicular to the up and down direction is referred to as the first direction (the directions of arrows B and C in Figs. 1 and 2), and the direction perpendicular to the up and down direction and the first direction is referred to as the second direction (the directions of arrows D and E in Figs. 1 and 2).

As shown in Figures 1 to 4, the trackball device 10 is configured to include a housing 20, an inner case 30, a circuit board 50, a pair of sensor units 60 as sensors, and a pair of sensor holders 70 as pressing members. The trackball device 10 also has a sphere 40 housed within the housing 20. Each component of the trackball device 10 will be described below.

(Regarding the housing 20)
As shown in Figs. 1, 3, and 4, the housing 20 constitutes the outer shell of the trackball device 10. The housing 20 is generally formed in a substantially cylindrical shape with the vertical direction as the axial direction. The housing 20 is configured to include an upper housing member 22 constituting the upper part of the housing 20 and a lower housing member 24 constituting the lower part of the housing 20, and the housing 20 is configured by assembling the upper housing member 22 and the lower housing member 24 to each other. The diameter of the upper housing member 22 is set smaller than the diameter of the lower housing member 24, and the housing 20 is formed in a substantially stepped cylindrical shape. A bent portion 22A bent radially inward is formed at the upper end of the upper housing member 22, and the bent portion 22A is formed over the entire circumferential circumference of the upper housing member 22. As a result, an exposure hole 22B is formed as an exposure portion penetrating in the vertical direction at the radial inner side of the housing 20 relative to the bent portion 22A at the upper end of the housing 20.

(Regarding the inner case 30)
As shown in Figs. 2 to 6, the inner case 30 is made of a transparent resin material and is formed in a concave shape that is open to the upper side. Specifically, the inner case 30 is formed in a substantially bowl shape that is open to the upper side, and is configured to include a bottom 31 that constitutes the lower end of the inner case 30, and a side wall 32 that extends upward from the bottom 31. The bottom 31 is formed in a substantially bottomed cylindrical shape that is relatively shallow and opens to the upper side, and the bottom wall of the bottom 31 constitutes the bottom wall of the inner case 30. The side wall 32 is formed in a stepped shape in a side cross-sectional view seen from the radial outside of the inner case 30. Specifically, the side wall 32 is configured to include a first step portion 32A that constitutes the upper end of the side wall 32, a second step portion 32B that constitutes the vertical middle portion of the side wall 32, and a slope portion 32C that constitutes the lower end of the side wall 32. In a side cross-sectional view, the slope portion 32C is inclined radially inward as it approaches the lower side, and the lower end portion of the slope portion 32C is connected to the upper end portion of the bottom portion 31. The inner case 30 is accommodated in the lower housing member 24 and attached to the lower housing member 24 by claw fitting or the like. As a result, the bottom wall of the inner case 30 is disposed below the exposure hole 22B of the housing 20.

The bottom wall of the inner case 30 has a plurality of exhaust holes 33 (four in this embodiment) (see Figs. 4 and 5) formed therethrough to exhaust foreign matter such as dust that has entered the inner case 30 through the exposure hole 22B of the housing 20. The exhaust holes 33 are formed as elongated holes extending in the first direction and are arranged at equal intervals in the second direction. The inner peripheral surface of the exhaust holes 33 on one side in the second direction (the side indicated by the arrow D in Fig. 4) is configured as a first inclined surface 33A, and the inner peripheral surface of the exhaust holes 33 on the other side in the second direction (the side indicated by the arrow E in Fig. 4) is configured as a second inclined surface 33B.

When viewed from the longitudinal direction of the discharge hole 33, the first inclined surface 33A is inclined toward one side of the second direction as it moves downward. The second inclined surface 33B is arranged parallel to the first inclined surface 33A. That is, when viewed from the longitudinal direction of the discharge hole 33, the discharge hole 33 opens in a direction inclined with respect to the vertical direction, and the area of the inner opening 33C (see FIG. 4) on the inner periphery side of the inner case 30 in the discharge hole 33 and the area of the outer opening 33D (see FIG. 4) on the outer periphery side of the inner case 30 in the discharge hole 33 are set to be the same. In addition, in a plan view seen from above, the first inclined surface 33A and the second inclined surface 33B do not overlap, and a minute gap G is formed between the first inclined surface 33A and the second inclined surface 33B in the second direction (the short direction of the discharge hole 33). That is, the first inclined surface 33A and the second inclined surface 33B are configured so as not to be undercut with each other in the vertical direction. Furthermore, the minute gap G is set to 1/4 or less of the length L of the inner opening 33C in the second direction.

As shown in FIG. 4, the second step portion 32B of the inner case 30 has a plurality of support portions 34 (three in this embodiment), which are arranged at 120 degrees in the circumferential direction of the inner case 30 (only one support portion 34 is shown in FIG. 4). The support portion 34 protrudes radially inward from the inner peripheral surface of the second step portion 32B, and the inner peripheral surface of the support portion 34 is inclined radially outward as it moves upward in a side cross-sectional view. The inner peripheral surface of the support portion 34 has a support recess 34A formed thereon, which is formed in a substantially hemispherical recess that is open to the upper side. A support ball 42 is housed in the support recess 34A, which is formed in a spherical shape and is fixed to the support recess 34A.

A spherical sphere 40 is housed inside the inner case 30, and is placed above the support ball 42 and rotatably supported by the support ball 42. The upper part of the sphere 40 protrudes upward from the inner case 30. Specifically, the center CP of the sphere 40 is disposed above the inner case 30. The upper end of the sphere 40 protrudes upward from the exposure hole 22B of the housing 20 and is exposed to the outside of the housing 20 so as to be rotatable (see Figures 1 and 3).

A fixing boss 35 for fixing a circuit board 50 (described later) is formed in the second step portion 32B of the inner case 30 at a position corresponding to the support portion 34. The fixing boss 35 is formed in a generally cylindrical shape with the axial direction being the up-down direction, and protrudes downward from the second step portion 32B.

As shown in Figures 2 to 6, the inner case 30 is provided with a pair of mounting mechanisms 36 for mounting the sensor unit 60 described below, and the pair of mounting mechanisms 36 are formed on the outer periphery of one side in the first direction (the side indicated by the arrow B in Figure 3) of the inner case 30 and on the outer periphery of one side in the second direction. Below, the configuration of the mounting mechanisms 36 will be described using the mounting mechanisms 36 formed on the one side in the first direction.

The mounting mechanism 36 has a sensor mounting portion 37 formed on the outer periphery of the inner case 30, and the sensor mounting portion 37 is formed in a substantially rectangular concave shape that is open to the radial outside of the sphere 40 in a cross-sectional view seen from the second direction. The bottom surface of the sensor mounting portion 37 is configured as a mounting surface 37A, and the mounting surface 37A is inclined downward toward one side of the first direction in a cross-sectional view seen from the second direction (see FIG. 3). If the direction perpendicular to the mounting surface 37A is the orthogonal direction (the direction of arrow F and the direction of arrow G in FIG. 3), the mounting surface 37A is inclined when viewed from the second direction so that the overhead line LN passing through the center of the mounting surface 37A and the center CP of the sphere 40 extends along the orthogonal direction. That is, the mounting surface 37A is disposed below the center CP of the sphere 40 and is formed along a surface perpendicular to the radial direction of the sphere 40.

The mounting mechanism 36 has a pair of locking portions 38, which are disposed on one circumferential side and the other circumferential side of the inner case 30 with respect to the sensor mounting portion 37. The locking portions 38 are formed in a substantially rectangular column shape extending in the vertical direction and protrude from the side wall 32 of the inner case 30 to one side in the first direction. A locking hole 38A is formed through the locking portion 38 in the second direction, and the locking hole 38A is formed in a long hole shape with the vertical direction as the longitudinal direction. The surface on one side in the first direction at the lower end of the locking hole 38A is configured as a locking surface 38B, which is inclined toward the other side in the first direction as it approaches the lower side when viewed from the second direction. Specifically, the locking surface 38B is disposed parallel to the mounting surface 37A.

A stopper portion 38C (see FIG. 2) is formed at the lower end of the engagement portion 38, protruding inward in the second direction. The stopper portion 38C is formed in a generally trapezoidal block shape extending in the first direction, and the other end of the stopper portion 38C in the first direction is disposed adjacent to the lower side of the engagement hole 38A. The portion of the upper surface of the stopper portion 38C on one side in the first direction is inclined so as to follow the orthogonal direction when viewed from the second direction.

(Regarding the circuit board 50)
The circuit board 50 is formed in a substantially circular plate shape with the plate thickness direction being the up-down direction, and is disposed below the inner case 30. A substantially circular insertion hole 50A is formed through the center of the circuit board 50, and the bottom 31 of the inner case 30 is disposed within the insertion hole 50A. The bottom wall of the inner case 30 is disposed below the circuit board 50. A fixing hole 50B (see FIG. 4) is formed through the circuit board 50 at a position corresponding to the fixing boss 35 of the inner case 30, and a fixing screw 52 is inserted into the fixing hole 50B from below and screwed into the fixing boss 35, thereby fixing the circuit board 50 to the inner case 30.

A notch 50C is formed on the outer periphery of the circuit board 50 at one side in the first direction and one side in the second direction, and the notch 50C is formed in a concave shape that is open radially outward of the circuit board 50. In addition, a connector 54 is provided on the upper surface of the outer periphery of the circuit board 50 at the other side in the second direction, and the connector 54 is configured to connect the trackball device 10 to an external device.

(Regarding the sensor unit 60)
The pair of sensor units 60 are each attached to a sensor attachment portion 37 of the inner case 30 by using a sensor holder 70 described later. Hereinafter, the configuration of the sensor unit 60 will be described using the sensor unit 60 attached to the sensor attachment portion 37 on one side of the inner case 30 in the first direction.

The sensor unit 60 is configured as an optical sensor that detects the amount of rotation of the sphere 40. The sensor unit 60 includes a sensor board 62 and a sensor body 64. The sensor board 62 is formed in a substantially rectangular plate shape with the orthogonal direction being the plate thickness direction, and is disposed on one side in the orthogonal direction (the side indicated by the arrow F in FIG. 3) relative to the sensor mounting portion 37. The lower end of the sensor board 62 is inserted into the cutout portion 50C of the circuit board 50, and the sensor board 62 and the circuit board 50 are configured to be engageable in the second direction. The sensor board 62 is electrically connected to the circuit board 50 at its lower end. Furthermore, a circular positioning hole 62A is formed through the lower portion of the sensor board 62.

The sensor body 64 is formed in a substantially rectangular parallelepiped shape with the orthogonal direction as its thickness direction, and is connected to the sensor board 62, protruding from the sensor board 62 to one side and the other side in the orthogonal direction. The sensor body 64 has a light-projecting section and a light-receiving section (not shown). The light-projecting section irradiates light toward the center CP of the sphere 40, and the light reflected by the outer surface of the sphere 40 is received by the light-receiving section, allowing the sensor body 64 to detect the amount of rotation of the sphere 40. The sensor body 64 is also positioned so that the overhead line LN described above passes through the center of the sensor body 64.

A flange 64A is formed on the outer periphery of the other orthogonal end of the sensor body 64, and the flange 64A is formed around the entire circumferential circumference of the sensor body 64. The flange 64A is fitted into the sensor mounting portion 37 of the inner case 30, and the movement of the sensor body 64 in the circumferential direction and upward of the inner case 30 is restricted by the sensor mounting portion 37. The end face on the other orthogonal side of the sensor body 64 is configured as an abutment surface 64B, and the abutment surface 64B is disposed adjacent to the mounting surface 37A on one side in the orthogonal direction.

(Regarding the sensor holder 70)
2 to 7, the pair of sensor holders 70 are attached to the locking portions 38 of the attachment mechanism 36 in the inner case 30, and are configured as members that hold the sensor units 60. Below, the configuration of the sensor holder 70 will be described using the sensor holder 70 attached to the attachment mechanism 36 on one side of the inner case 30 in the first direction.

The sensor holder 70 includes a holder main body 72 as a main body, and a pair of arm portions 74. The holder main body 72 is formed in a generally rectangular plate shape with the orthogonal direction being the plate thickness direction and the second direction being the width direction. A crank-shaped crank portion 72A is formed in the middle of the holder main body 72 in the vertical direction, and the upper portion of the holder main body 72 is disposed on one side in the orthogonal direction relative to the lower portion of the holder main body 72. The holder main body 72 is disposed adjacent to one side in the orthogonal direction of the sensor unit 60.

A positioning pin 72B is formed on the lower part of the holder main body 72. The positioning pin 72B is formed in a substantially cylindrical shape with the orthogonal direction as the axial direction, and protrudes from the holder main body 72 to the other side in the orthogonal direction. The positioning pin 72B is fitted into the positioning hole 62A of the sensor board 62 to determine the relative position of the sensor holder 70 with respect to the sensor unit 60. A handle portion 72C is formed in the widthwise center of the holder main body 72. The handle portion 72C is formed in a rib shape with the width direction of the holder main body 72 as the plate thickness direction, and protrudes from the sensor main body 64 to one side in the orthogonal direction. This allows the operator to grip the handle portion 72C and attach the sensor holder 70 to the inner case 30. The upper part of the tip of the handle portion 72C is arranged to face the inner peripheral surface of the housing 20 with a predetermined gap in the first direction.

The pair of arm portions 74 are formed in a generally long plate shape with the orthogonal direction being the plate thickness direction and the second direction being the longitudinal direction, and extend from the upper portion of the holder main body portion 72 to one side and the other side in the second direction. The tip side portion of the arm portion 74 is bent to the other side in the orthogonal direction, and the tip of the arm portion 74 is disposed adjacent to the inside of the locking portion 38 of the inner case 30 in the second direction. The tip of the arm portion 74 is formed with a locking hook 74A that protrudes outward in the second direction, and the locking hook 74A is inserted into the locking hole 38A of the inner case 30 and is locked to the locking surface 38B of the locking hole 38A. In this way, the sensor holder 70 is attached to the inner case 30.

The arm portion 74 is configured to be elastically deformable in the orthogonal direction. When the sensor holder 70 is attached to the inner case 30, the arm portion 74 is elastically deformed so that the tip of the arm portion 74 is displaced to the other orthogonal direction side. As a result, the holder main body portion 72 is configured to press the sensor unit 60 to the other orthogonal direction side (the sphere 40 side). That is, the sensor unit 60 is attached to the inner case 30 with the abutment surface 64B of the sensor main body 64 abutting against the mounting surface 37A of the inner case 30. The tip of the arm portion 74 is disposed adjacent to the upper side of the stopper portion 38C of the inner case 30. This restricts the downward movement of the sensor unit 60 and the sensor holder 70.

Although the material of the sensor holder 70 is not particularly specified, the sensor holder 70 may be made of a resin material, and the arm portion 74 may be configured to be elastically deformable in the perpendicular direction. The sensor holder 70 may also be made of an elastic material such as rubber, and the entire sensor holder 70 may be configured to be elastically deformable.

(Action and Effect)
Next, the operation and effects of this embodiment will be described.

In the trackball device 10 configured as described above, the sphere 40 is rotatably housed in the transparent inner case 30, and the upper end of the sphere 40 is exposed from the exposure hole 22B of the housing 20 so that it can be rotated. A sensor unit 60 is provided on the outer periphery of the inner case 30, and the sensor unit 60 is configured as an optical sensor. When light is irradiated from the light-emitting portion of the sensor body 64 toward the sphere 40, the light passes through the transparent inner case 30 and is reflected by the sphere 40. The light reflected by the sphere 40 passes through the inner case 30 and is received by the light-receiving portion of the sensor body 64. This allows the sensor unit 60 to detect the amount of rotation of the sphere 40.

Here, the bottom wall of the inner case 30 is formed with a discharge hole 33 penetrating therethrough. As a result, foreign matter such as dust that has entered the inner case 30 can be discharged from the discharge hole 33 to the outside of the inner case 30. This makes it possible to suppress a decrease in the detection performance of the trackball device 10 due to foreign matter such as dust. In addition, the discharge hole 33 is formed in a long hole shape extending in the first direction, and the inner circumferential surface of the discharge hole 33 is configured to include a first inclined surface 33A and a second inclined surface 33B. When viewed from the longitudinal direction of the discharge hole 33, the first inclined surface 33A is inclined toward one side in the second direction as it moves downward, and the second inclined surface 33B is arranged parallel to the first inclined surface 33A. As a result, when viewed from the longitudinal direction of the discharge hole 33, it is possible to suppress the lower area of the bottom wall of the inner case 30 from being viewed from above, compared to the case in which the first inclined surface 33A and the second inclined surface 33B are configured as surfaces along the vertical direction. That is, the first inclined surface 33A and the second inclined surface 33B can provide a blind structure for the bottom wall of the inner case 30 in which the discharge hole 33 is formed. As a result, for example, the invisibility angle b (see FIG. 4) at which the lower area of the bottom wall of the inner case 30 is invisible relative to the horizontal direction when viewed from one side in the second direction can be made larger than in the above configuration. Therefore, foreign objects that have entered the inner case 30 can be discharged to the outside of the inner case 30 while preventing deterioration of the appearance of the trackball device 10.

In addition, since the exhaust hole 33 is formed in an elongated hole shape, the protection performance for the circuit board 50 can be improved. That is, for example, when removing the upper housing member 22 of the housing 20 from the lower housing member 24 and removing the sphere 40 to remove a foreign object that has entered the inner case 30, if the entire bottom wall of the inner case 30 is configured as an exhaust hole, the user can easily contact the circuit board 50 from the exhaust hole. Therefore, the protection performance for the circuit board 50 may be reduced. In contrast, in this embodiment, as described above, the exhaust hole 33 is formed in an elongated hole shape. Therefore, for example, even when removing the upper housing member 22 from the lower housing member 24 and removing the sphere 40 to remove a foreign object that has entered the inner case 30, the user's contact with the circuit board 50 from the exhaust hole 33 can be suppressed. Therefore, the protection performance for the circuit board 50 can be improved.

In addition, the first inclined surface 33A and the second inclined surface 33B are arranged in parallel in the discharge hole 33. That is, the area of the inner opening 33C on the inlet side of the discharge hole 33 and the area of the outer opening 33D on the outlet side are set to be the same. This allows foreign matter that has entered the inner case 30 to be efficiently discharged by the discharge hole 33.

In addition, in the discharge hole 33, the first inclined surface 33A and the second inclined surface 33B are entirely offset in the second direction in a plan view. That is, the first inclined surface 33A and the second inclined surface 33B do not overlap in a plan view, and do not form an undercut shape with respect to each other. This makes it possible, for example, to prevent the mold for molding the inner case 30 from having an undercut structure, and contributes to reducing the cost of the inner case 30.

In addition, in a plan view, a minute gap G is formed between the first inclined surface 33A and the second inclined surface 33B, and the length of the minute gap G in the second direction is set to 1/4 or less of the length L of the inner opening 33C in the second direction (short side direction). This makes it possible to minimize the visibility of the lower area of the bottom wall of the inner case 30 from the minute gap G when viewed from above, while avoiding an undercut structure between the first inclined surface 33A and the second inclined surface 33B.

A circuit board 50 is provided below the inner case 30, and the sensor unit 60 is disposed above the circuit board 50 and connected to the circuit board 50. Furthermore, an insertion hole 50A through which the bottom 31 of the inner case 30 is inserted is formed in the circuit board 50, and the bottom wall of the inner case 30 is disposed below the circuit board 50. Therefore, foreign matter discharged from the discharge hole 33 falls into an area below the circuit board 50. This makes it possible to prevent foreign matter discharged downward from the discharge hole 33 from accumulating around the sensor body 64. Therefore, it is possible to ensure the dustproof performance of the sensor unit 60 and maintain good detection accuracy of the sensor unit 60.

In addition, a plurality of discharge holes 33 are formed in the bottom wall of the inner case 30, and the plurality of discharge holes 33 are arranged at equal intervals in the second direction. This allows foreign matter that has entered the inner case 30 to be efficiently discharged to the bottom side of the inner case 30.

In this embodiment, the discharge hole 33 formed in the bottom wall of the inner case 30 is formed in an elongated hole shape, but the shape of the discharge hole 33 is not limited to this. For example, the discharge hole 33 may be configured as a circular or polygonal hole that penetrates in the vertical direction. In this case, as shown in Figures 8 (A) and (B), the inner circumferential surface 33E of the discharge hole 33 may be configured to be inclined toward the center line of the discharge hole 33 as it moves downward so that the area of the inner opening 33C of the discharge hole 33 is larger than the area of the outer opening 33D of the discharge hole 33. In the example shown in Figures 8 (A) and (B), the discharge hole 33 is configured as a circular hole. And the inner circumferential surface 33E of the discharge hole 33 corresponds to the inclined surface of the present invention. Furthermore, even in this case, the invisibility angle b that makes the lower area of the bottom wall of the inner case 30 invisible in the horizontal direction can be increased compared to when the inner circumferential surface of the discharge hole 33 is configured as a surface along the vertical direction.

In addition, in this embodiment, the first inclined surface 33A and the second inclined surface 33B of the discharge hole 33 are configured as linear inclined surfaces when viewed from the longitudinal direction of the discharge hole 33, but the first inclined surface 33A and the second inclined surface 33B may be formed in an arc shape (curved shape) when viewed from the longitudinal direction of the discharge hole 33.

In addition, in this embodiment, the first inclined surface 33A and the second inclined surface 33B of the discharge hole 33 do not overlap in a plan view, and a minute gap G is formed between the first inclined surface 33A and the second inclined surface 33B. Alternatively, the first inclined surface 33A and the second inclined surface 33B in the second direction may be set so that the minute gap G is zero, or the first inclined surface 33A and the second inclined surface 33B in the second direction may be set so that a part of the first inclined surface 33A and a part of the second inclined surface 33B overlap in a plan view.

10 Trackball device 20 Housing 22B Exposure hole (exposure portion)
30 Inner case 33 Discharge hole 33A First inclined surface (inclined surface)
33B Second slope (slope)
33C Inner opening 33D Outer opening 50 Circuit board 50A Insertion hole 60 Sensor unit (sensor)
L: Short side length of inner opening G: Minute gap

Claims (7)

a transparent inner case formed in a concave shape that is open upward;
a spherical body rotatably accommodated inside the inner case;
a housing that houses the inner case and the sphere and has an exposure portion that exposes a portion of the sphere to the outside so that the portion can be operated;
a sensor provided on an outer periphery of the inner case, facing an outer surface of the sphere with the inner case interposed therebetween, the sensor detecting rotation of the sphere;
a discharge hole formed in a bottom wall of the inner case for discharging dust from within the inner case;
Equipped with
A trackball device in which an inclined surface is formed on an inner peripheral surface of the discharge hole, and the inclined surface prevents visibility of a lower area of the bottom wall of the inner case. The discharge hole is formed in an elongated hole shape,
The trackball device according to claim 1, wherein the inclined surface includes a first inclined surface inclined with respect to the vertical direction when viewed from the longitudinal direction of the discharge hole, and a second inclined surface arranged parallel to the first inclined surface. The trackball device according to claim 2, wherein, in a plan view, the first inclined surface and the second inclined surface are entirely offset in the short direction of the discharge hole. A minute gap is formed between the first inclined surface and the second inclined surface in a plan view,
4. The trackball device according to claim 3, wherein the distance of the minute gap in the short-side direction of the discharge hole is set to 1/4 or less of the short-side length of the inner opening of the discharge hole. The trackball device of claim 1, wherein the inclined surface makes the area of the inner opening of the ejection hole larger than the area of the outer opening of the ejection hole. The trackball device according to any one of claims 1 to 5, wherein a plurality of the discharge holes are formed in the bottom wall of the inner case and are arranged at equal intervals. a circuit board is provided on the lower side of the inner case, and the sensor is disposed on the upper side of the circuit board and connected to the circuit board;
A trackball device as described in any one of claims 1 to 6, wherein the circuit board has an insertion hole through which the bottom of the inner case is inserted, and the bottom wall of the inner case is positioned lower than the circuit board.

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