Input device

Abstract

Provided is an input device with which a pressing operation can be correctly determined.　This input device comprises: an operation panel having an operation surface on which a pressing operation can be performed; a substrate disposed so as to face the operation panel in the pressing direction of the pressing operation on the operation panel; a plurality of elastic supports which support the operation panel with respect to the substrate and are elastically deformable; a plurality of displacement detection units which are arranged in a support region in which the plurality of elastic supports are arranged in a plan view, and detect the displacement of the operation panel due to the pressing operation on the operation surface; an output synthesis unit which generates a synthesized output signal obtained by synthesizing output signals of the plurality of displacement detection units; and a control unit which determines the presence or absence of the pressing operation on the operation panel on the basis of the synthesized output signal generated by the output synthesis unit.

Description

Input device

[0001] The present disclosure relates to an input device.

[0002] Conventionally, in order to detect a pressing operation for pressing a touch pad, there is an electronic device (a laptop computer) provided with a plurality of force sensors composed of piezoelectric elements or the like on the back side of the touch pad. The outputs of the plurality of force sensors are combined or averaged to determine the presence or absence of pressing. (See, for example, Patent Document 1).

[0003] U.S. Patent No. 9,400,582

[0004] By the way, in a conventional electronic device, when combining or averaging the outputs of a plurality of force sensors, if the signs of the outputs of any of the force sensors are different, there is a risk that the presence or absence of pressing cannot be correctly determined.

[0005] Therefore, an object is to provide an input device capable of correctly determining a pressing operation.

[0006] The input device according to an embodiment of the present disclosure includes an operation panel having an operation surface capable of a pressing operation, a substrate disposed to face the operation panel in a pressing direction of the pressing operation on the operation panel, a plurality of elastic supports that support the operation panel with respect to the substrate and are elastically deformable, a plurality of displacement detection units disposed within a support region where the plurality of elastic supports are disposed in a plan view and that detect displacement of the operation panel due to a pressing operation on the operation surface, an output combining unit that generates a combined output signal by combining output signals of the plurality of displacement detection units, and a control unit that determines the presence or absence of a pressing operation on the operation panel based on the combined output signal generated by the output combining unit.

[0007] An input device capable of correctly determining a pressing operation can be provided.

[0008] This figure shows the planar configuration of the input device of the embodiment. This figure shows the cross-section as seen along the line A-A in Figure 1. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the arrangement of multiple optical sensors capable of determining the presence or absence of a pressing operation with a single judgment threshold. This figure shows an example of the current value of the combined output signal of multiple optical sensors when a pressing operation is performed in patterns 1 to 8. This figure shows an example of the arrangement of multiple optical sensors and the distribution of the displacement amount of the top panel in the -Z direction in an input device with an irregularly shaped substrate and top panel. This figure shows an example of the arrangement of multiple optical sensors and the distribution of displacement of the top panel in the -Z direction in an input device with an irregularly shaped substrate and top panel. This figure shows an example of the arrangement of multiple optical sensors and the distribution of displacement of the top panel in the -Z direction in an input device with an irregularly shaped substrate and top panel. This figure shows an example of the current value of the combined output signal of multiple optical sensors when pressing operations are performed in patterns 9 to 11. This figure shows an example of the arrangement of multiple optical sensors with respect to the center of gravity in the input device of the embodiment. This figure shows an example of the arrangement of multiple optical sensors with respect to the center of gravity in the input device of the embodiment. This figure shows an example of the arrangement of multiple optical sensors with respect to the center of gravity in the input device of the embodiment. This figure shows an example of the linear arrangement of the elastic support, pressing position, optical sensor, and center of gravity. This figure shows an example of the arrangement of optical sensors within an operating area surrounded by two adjacent pressing positions and the center of gravity. This figure shows another example of the arrangement of optical sensors within an operating area surrounded by two adjacent pressing positions and the center of gravity. This figure shows the circuit configuration of the input device of the embodiment. This is a characteristic diagram showing an example of the relationship between the gap detected by the optical sensor and the current value of the combined output signal.This diagram illustrates an example of the switching process for areas 1 to 5. This flowchart shows an example of the reference voltage switching process performed by the control unit. This timing chart shows an example of the operation of the input device in this embodiment.

[0009] The following describes embodiments to which the input device of this disclosure is applied.

[0010] <Embodiment> Figure 1 is a diagram showing the planar configuration of the input device 100 of the embodiment. Figure 2 is a diagram showing the cross-section as seen by the line A-A in Figure 1. In the following, the XYZ coordinate system will be defined and explained. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are mutually orthogonal. Also, in the following, for the sake of explanation, the -Z direction side may be referred to as the lower side or bottom, and the +Z direction side as the upper side or top, but this does not represent a universal up-down relationship. Also, a planar view means viewing from the XY plane. Also, in the following, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand.

[0011] <Configuration of Input Device 100> The input device 100 includes a substrate 110, an elastic support 120, a top panel 130, an electrostatic sensor 140, and an optical sensor 150. The top panel 130 is an example of an operation panel. The optical sensor 150 is an example of a displacement detection unit. As an example, the input device 100 includes four elastic supports 120 and four optical sensors 150. The input device 100 may include at least three elastic supports 120 and at least two optical sensors 150. The number of elastic supports 120 and optical sensors 150 do not need to be the same and may be different.

[0012] In addition to these components, the input device 100 includes a detection circuit and an MCU (microcontroller unit) for detecting whether or not a pressing operation is performed on the operating surface (upper surface) 130A of the top panel 130, but these are omitted in Figures 1 and 2. Figure 2 shows the user's fingertip FT. The fingertip FT is an example of an operating body.

[0013] An operating section 131 is arranged on the operating surface 130A. For example, the operating section 131 is arranged within the sensor area where the electrostatic sensor 140 is located in a plan view. The sensor area where the electrostatic sensor 140 is located means the inside of the outer edge of the electrostatic sensor 140 in a plan view. Figure 1 shows four operating sections 131 as an example, but at least one operating section 131 is sufficient. Also, Figure 1 shows a rectangular operating section 131 in a plan view as an example, but the shape of the operating section 131 in a plan view is not limited to a rectangle; it may be circular, elliptical, or the like.

[0014] The user can select an operation section 131 by touching (contacting) one of the operation sections 131 on the operating surface 130A of the top panel 130 with their fingertip FT. The user can also confirm the operation on the selected operation section 131 by performing a pressing operation by pressing the operation section 131 in the -Z direction. The input device 100 determines whether one of the operation sections 131 has been selected based on the output of the electrostatic sensor 140, and determines whether a pressing operation has been performed based on the output of the optical sensor 150. The input device 100 can be operated with means other than the fingertip FT, but the following description will assume that it is operated with the fingertip FT.

[0015] The input device 100 outputs data representing the operation performed on the user's fingertip FT operating surface 130A to the target device connected to the input device 100. The input device 100 may remotely control the target device, or it may be integrated with the target device. Furthermore, the input device 100 may be portable, or it may be permanently installed on a wall or the like.

[0016] <Substrate 110> The substrate 110 is a wiring board. As an example, a wiring board of FR-4 (Flame Retardant type 4) can be used as the substrate 110. As an example, the substrate 110 is rectangular in plan view, but it is not limited to a rectangular shape and may be circular, elliptical, or triangular or polygonal with pentagons or more. Furthermore, the substrate 110 may have an irregular shape, such as a shape in which part is recessed in plan view, or a shape in which part of the outer edge in plan view is composed of a hypotenuse.

[0017] The light-receiving and light-emitting unit 151 of the light sensor 150 is located on the upper surface of the substrate 110. The light-receiving and light-emitting unit 151 emits light toward the reflector 152 and receives the reflected light reflected by the reflector 152. Detection circuits and MCUs may also be located on the substrate 110, but these are omitted in Figures 1 and 2.

[0018] <Elastic Support 120> As an example, the elastic support 120 is positioned at the four corners of the upper surface of the substrate 110 in a plan view, and supports the top panel 130 relative to the substrate 110. In Figure 2, the elastic support 120 is positioned between the top panel 130 and the substrate 110, with the lower end of the elastic support 120 fixed to the upper surface of the substrate 110 and the upper end of the elastic support 120 fixed to the lower surface of the operation panel 130, thereby supporting the operation panel 130 relative to the substrate 110. However, the elastic support 120 is not limited to the configuration in which the lower end is fixed to the substrate 110 as described above. For example, if there is a member such as a case surrounding the substrate 110, the elastic support 120 may be configured such that the lower end of the elastic support 120 is fixed to the member such as the case, and the upper end of the elastic support 120 is fixed to the lower surface of the operation panel 130, thereby supporting the operation panel 130 relative to the substrate 110. Furthermore, the input device 100 may, for example, have a configuration in which the lower end of at least one elastic support 120 is fixed to the upper surface of the substrate 110, and the lower end of another elastic support 120 is fixed to a member such as a case. The elastic support 120 is elastically deformable in the Z direction and is made of urethane rubber, for example. The elastic support 120 only needs to be elastically deformable in the Z direction and may be made of an elastic material such as rubber other than urethane rubber. Also, although Figure 1 shows a rectangular elastic support 120 in plan view, the shape of the elastic support 120 in plan view is not limited to a rectangle, but may be circular, elliptical, triangular, a polygon with pentagons or more sides, or L-shaped, etc.

[0019] Because the elastic support 120 is elastically deformable in the Z direction, when various parts of the operating surface 130A are pressed with the same force in the -Z direction, the amount of displacement in the -Z direction is maximized at the part of the top panel 130 located directly above the elastic support 120 in a plan view, and the amount of displacement in the -Z direction is minimized at the center of the top panel 130 in a plan view. Since the four elastic support 120s are located at the four corners of the substrate 110 in a plan view, for example, the amount of displacement of the top panel 130 in the -Z direction is greater at the parts closer to the elastic support 120 in a plan view and smaller at the parts closer to the center in a plan view. Thus, when the top panel 130 is pressed in the -Z direction, it displaces in the -Z direction. For this reason, the pressing operation is equivalent to a downward pressing operation that pushes the top panel 130 down in the -Z direction. The -Z direction, which is the direction in which the top panel 130 is pushed down by the pressing operation, is an example of the pressing direction of the pressing operation.

[0020] In a plan view, the elastic support 120 is located outside the four optical sensors 150. In other words, the four optical sensors 150 are positioned within the support area where the four elastic support 120 are located in a plan view. This is to ensure that the combined output signal, which is the sum of the output signals of the four optical sensors 150, always increases regardless of which part of the operating surface 130A is pressed in the -Z direction. The statement that the combined output signal always increases means that the absolute value of the combined output signal always increases. The input device 100 determines whether or not a pressing operation has occurred based on the combined output signals of the four optical sensors 150, and therefore the four optical sensors 150 and the four elastic support 120 are arranged in this way in a plan view.

[0021] The support region in which the four elastic supports 120 are arranged in a plan view is the region formed by connecting any part of the four elastic supports 120 in a plan view. In this case, the support region is the area enclosed by the line connecting any part of the four elastic supports 120 in a plan view. For example, the support region in which the four elastic supports 120 are arranged in a plan view is the region formed by connecting the outer edges of each elastic support 120 in a plan view. In Figure 1, the four elastic supports 120 are arranged at the four corners of the substrate 110, so the support region in which the four elastic supports 120 are arranged in a plan view is approximately equal to the outer edge of the substrate 110. In this case, the support region is the area enclosed by the line along the outer edge of the substrate 110. Alternatively, the support region in which the four elastic supports 120 are arranged in a plan view may be, for example, the region formed by connecting the centers of each elastic support 120 in a plan view. In this case, the support region is the area enclosed by the line connecting the centers of the four elastic supports 120 in a plan view. Furthermore, the support region in which the four elastic supports 120 are arranged in a plan view may, for example, be the region formed by connecting the parts of each elastic support 120 that are closest to the center or centroid of the four elastic supports 120 in a plan view. In other words, the support region in this case is the area enclosed by the line along the outer edge of the electrostatic sensor 140 in Figure 1. Here, we have described the support region in which four elastic supports 120 are arranged, but the meaning of the support region in which three or more elastic supports 120 are arranged is the same.

[0022] Here, let's consider the case where the arrangement of the four optical sensors 150 and the four elastic supports 120 in a plan view is reversed, and the four optical sensors 150 are located outside the support area where the four elastic supports 120 are located in a plan view. In such a case, when the part of the operating surface 130A that is outside the four elastic supports 120 in a plan view (for example, the +X side end of the operating surface 130A and the central part in the Y direction) is pressed in the -Z direction, the part of the top panel 130 on the +X side is displaced in the -Z direction, and the part of the top panel 130 on the -X side is displaced in the +Z direction. In other words, when viewed in an XZ plane view, the top panel 130 may operate like a seesaw. In such a case, the output signals of the two optical sensors 150 on the +X side increase, and the output signals of the two optical sensors 150 on the -X side decrease, and the combined output signal obtained by combining the output signals of the four optical sensors 150 due to the increase and decrease will hardly change.

[0023] The input device 100 has four optical sensors 150 positioned within the support area where the four elastic supports 120 are located, in order to determine whether or not a pressing operation has been performed based on a composite output signal that always increases regardless of which part of the operating surface 130A is pressed in the -Z direction.

[0024] Furthermore, in order to ensure that the combined output signal always increases when the operating surface 130A is pressed in the -Z direction, the position of the operating unit 131 that operates on the operating surface 130A is positioned in a plan view within the support area where the four elastic supports 120 are arranged in a plan view.

[0025] <Top Panel 130> The top panel 130 is, for example, a plate-shaped member made of resin, and for example, is rectangular in plan view. The upper surface of the top panel 130 is the operating surface 130A. The lower surface of the top panel 130 is the opposing surface 130B that faces the substrate 110. For example, an electrostatic sensor 140 is provided on the opposing surface 130B of the top panel 130. The top panel 130 may be part of the housing or the like of the device to be operated, for example, if the input device 100 is integrally provided with the device to be operated.

[0026] An operating section 131 is provided on the operating surface 130A of the top panel 130. The operating section 131 is represented, for example, by letters, numbers, or symbols such as signs printed on the operating surface 130A. The portion of the operating surface 130A where the operating section 131 is located may have indentations or other textures.

[0027] The operation unit 131 is an operation unit for selecting and confirming a predetermined function of the device to be operated. The symbols marked on the operation surface 130A represent, for example, predetermined functions of the device to be operated. Since each operation unit 131 is located in a position that overlaps with the electrostatic sensor 140 in a plan view, it is possible to determine which operation unit 131 the fingertip FT is touching based on the output of the electrostatic sensor 140.

[0028] When a user touches an operation unit 131 with their fingertip FT, the input device 100 determines which operation unit 131 has been selected based on the output of the electrostatic sensor 140, and determines whether or not a pressing operation has been performed on the operation unit 131 based on the combined output signal of the four optical sensors 150. The input device 100 notifies the target device of the operation content determined by the pressing operation. As a result, the target device executes a predetermined function or the like corresponding to the operation unit 131 on which the pressing operation was performed.

[0029] For example, if there is only one operating unit 131 on the top panel 130, the electrostatic sensor 140 does not need to be provided on the opposing surface 130B of the top panel 130. In this case, the input device 100 is an input device for operating one operating unit 131.

[0030] Furthermore, a display panel such as a liquid crystal or organic electroluminescent (EL) display may be positioned below the electrostatic sensor 140 on the opposing surface 130B of the top panel 130. In this case, since the top panel 130 and the electrostatic sensor 140 are transparent, the display can be viewed through the top panel 130 and the electrostatic sensor 140, and the operation unit 131 may be a GUI (Graphical User Interface).

[0031] <Electrostatic Sensor 140> The electrostatic sensor 140 is provided on the opposing surface 130B of the top panel 130, and, as an example, has a film substrate and electrodes formed on the film substrate. The electrodes of the electrostatic sensor 140 are composed of, as an example, a plurality of electrodes extending in the X direction and a plurality of electrodes extending in the Y direction, and by applying a driving voltage sequentially, capacitance can be generated at the intersection of the plurality of electrodes extending in the X direction and the plurality of electrodes extending in the Y direction. Note that the electrodes of the electrostatic sensor 140 are not limited to the above configuration, and may be configured, for example, with rectangular electrodes arranged in the X and Y directions. Also, if a display panel is placed below the electrostatic sensor 140, it may be composed of a transparent film substrate and electrodes.

[0032] <Optical Sensor 150> The optical sensor 150 is, for example, a reflective optical sensor and has a light-emitting / receiving unit 151 and a reflector 152. The light-emitting / receiving unit 151 is provided on the upper surface of the substrate 110 and has a light-emitting unit and a light-receiving unit. The light-emitting unit and light-receiving unit of the light-emitting / receiving unit 151 are oriented upwards. The reflector 152 is attached to the lower surface of the electrostatic sensor 140. For example, the reflector 152 can be fixed to the lower surface of the electrostatic sensor 140 with adhesive or the like.

[0033] The light sensor 150 emits light upward from the light-receiving unit 151 and detects the displacement of the top panel 130 in the -Z direction by receiving the reflected light reflected by the reflector 152. If the top panel 130 and the electrostatic sensor 140 are transparent, and a display panel such as a liquid crystal or organic EL is positioned below the electrostatic sensor 140, for example, the part of the display panel facing the light-receiving unit 151 can be used as the reflector 152.

[0034] The four optical sensors 150 are positioned so that, in a plan view, when a pressing operation is performed within the support area where the four elastic supports of the operating surface 130A are located, the control unit of the MCU can determine whether or not a pressing operation has been performed on the operating surface 130A using a single determination threshold. This arrangement will be explained using Figures 3A to 8B.

[0035] <Arrangement of Multiple Optical Sensors 150 Capable of Determining the Presence or Absence of a Pressing Operation with a Single Judgment Threshold> Figures 3A to 3H show an example of the arrangement of multiple optical sensors 150 capable of determining the presence or absence of a pressing operation with a single judgment threshold. Figures 3A to 3H show the arrangement of the substrate 110, four elastic supports 120, top panel 130, and four optical sensors 150 in the input device 100. The positions, shapes, and relative sizes of the substrate 110, four elastic supports 120, top panel 130, and four optical sensors 150 shown in Figures 3A to 3H are the same as those of the substrate 110, four elastic supports 120, top panel 130, and four optical sensors 150 shown in Figure 1.

[0036] Furthermore, Figures 3A to 3H show the centers of gravity G of the four elastic supports 120 in a plan view. The center of gravity G is the center of gravity of the center of each elastic support 120 in a plan view. Also, Figures 3A to 3H show the position where the pressing operation is performed as the pressing position P. The pressing position P is the position where the operating part 131 (see Figure 1) is provided. Here, it is described as the pressing position P, but it is synonymous with the position where the operating part 131 is provided. The pressing positions P for patterns 1 to 8 in Figures 3A to 3H are all different, but all are located within the support area where the four elastic supports 120 are arranged in a plan view. Note that here, the centers of gravity G of the four elastic supports 120 are used for explanation, but instead of the centers of gravity G of the four elastic supports 120, the centers of the four elastic supports 120 in a plan view may be used.

[0037] Furthermore, Figures 3A to 3H show the distribution of displacement of the top panel 130 in the -Z direction. The ranges with median displacement values ​​of 0.125 mm, 0.25 mm, 0.375 mm, 0.5 mm, 0.625 mm, 0.75 mm, 0.875 mm, and 1 mm are shown separately. These displacement values ​​were obtained from simulations.

[0038] In Figures 3A to 3H, the four optical sensors 150 are positioned between the center of gravity G and the four elastic supports 120, and the distance between the four optical sensors 150 and the center of gravity G is equal. More specifically, the center of each optical sensor 150 in a plan view lies on the straight line connecting the center of gravity G and each elastic support 120, and the distance between the four optical sensors 150 and the center of gravity G is equal. In other words, the four optical sensors 150 are arranged on a single circle (concentric circle) centered on the center of gravity G.

[0039] As shown in Figures 3A to 3H, in the distribution of displacement of the top panel 130 in the -Z direction due to the pressing position P for patterns 1 to 8, it was confirmed that the displacement of the top panel 130 was greatest in the part that is close to the pressing position P and closest to the outer edge of the top panel 130 in a plan view, and the displacement was smallest in the part located on the opposite side in a plan view from the part with the greatest displacement.

[0040] Furthermore, it was confirmed that even in the area with the smallest displacement, there was displacement in the -Z direction. This indicates that when a pressing operation is performed on the top panel 130 within the support area where the four elastic supports 120 are positioned in a plan view, no part lifts up like a seesaw, and the entire top panel 130 is displaced in the -Z direction.

[0041] In such cases, the current value of the combined output signal obtained by combining the output signals of the four optical sensors 150 is as shown in Figure 4. Figure 4 is a diagram showing an example of the current value (mA) of the combined output signal of the four optical sensors 150 when pressing operations are performed in patterns 1 to 8.

[0042] As shown in Figure 4, the current value of the combined output signal of the four optical sensors 150 when pressing operations were performed in patterns 1 to 8 was approximately constant at about 2.2 mA. Therefore, when a pressing operation is performed at pressing position P in patterns 1 to 8, it is possible to determine whether or not a pressing operation has been performed using a single threshold. In this way, regardless of the position on the top panel 130 where the pressing operation is performed, the current value of the combined output signal of the four optical sensors 150 remains constant, making it possible to determine whether or not a pressing operation has been performed using a single threshold.

[0043] In order to be able to determine the presence or absence of a pressing operation using one threshold value, the distances between each of the four optical sensors 150 and the center of gravity G do not have to be exactly equal, and there may be a certain distance difference. That is, the four optical sensors 150 may have a distance difference from the center of gravity G as long as the combined output signal is within a range where the presence or absence of a pressing operation can be determined using one threshold value.

[0044] The details of the determination process for the presence or absence of a pressing operation will be described later. As an example, the combined output signal obtained by combining the output signals of the four optical sensors 150 is amplified by an inverting amplifier circuit, and the output signal of the operational amplifier of the inverting amplifier circuit is digitized by the MCU into a gradation value of 12 bits (4096 gradations), and the presence or absence of a pressing operation is determined based on the gradation value of 4096 gradations. In this case, by using one threshold value for the gradation value of 4096 gradations generated from the output signal of the operational amplifier based on the combined output signal of the four optical sensors 150 when a pressing operation is performed in patterns 1 to 8, it is possible to determine the presence or absence of a pressing operation. This is because the distance differences between each of the four optical sensors 150 and the center of gravity G are such that the combined output signal becomes a substantially constant value when a pressing operation is performed in patterns 1 to 8.

[0045] Also, FIGS. 3A to 3H show a configuration in which the four optical sensors 150 are arranged on a circle centered on the center of gravity G in the plan view of the four elastic supports 120. Instead of the center of gravity G, the center in the plan view of the four elastic supports 120 may be used. That is, the four optical sensors 150 may be arranged on a circle centered on the center in the plan view of the four elastic supports 120.

[0046] <Combined Output Signal in the Case of an Irregular Shape> FIGS. 5A to 5C are diagrams showing an example of the arrangement of a plurality of optical sensors 150 and the distribution of the displacement amount in the -Z direction of the top panel 130 in the input device 100 in which the substrate 110 and the top panel 130 are irregularly shaped.

[0047] The shapes of the substrate 110 and the top panel 130 of the input device 100 shown in FIGS. 5A to 5C in the plan view, as an example, have a recess in the central portion of the long side on the +Y direction side of a rectangle having a long side in the X direction, recessed toward the -Y direction side.

[0048] As an example, the four elastic supports 120 are provided at the four corners of the substrate 110. The four optical sensors 150 are provided within a support area where the four elastic supports 120 are arranged in a plan view. In such a case, the support area where the four elastic supports 120 are arranged in a plan view is, as described above using FIG. 1, for example, an area connecting the outer ends of each elastic support 120 in a plan view. That the four optical sensors 150 are provided within the support area where the four elastic supports 120 are arranged in a plan view means that the four optical sensors 150 are provided within an area obtained by removing the concave portion of the substrate 110 from the area connecting the outer ends of each elastic support 120 in a plan view.

[0049] The four optical sensors 150 are arranged at line-symmetrical positions with a straight line passing through the center of gravity G and parallel to the Y-axis as the axis of symmetry. More specifically, two of the four optical sensors 150 are arranged on the -X direction side of the axis of symmetry, and the remaining two optical sensors 150 are arranged on the +X direction side of the axis of symmetry. For this reason, the distances between the two optical sensors 150 on the side closer to the center of gravity G among the four optical sensors 150 and the center of gravity G are equal, and the distances between the two optical sensors 150 on the side farther from the center of gravity G among the four optical sensors 150 and the center of gravity G are equal.

[0050] In the input device 100 shown in FIGS. 5A to 5C, the displacement amount in the -Z direction of the top panel 130 and the composite output signal when a pressing operation is performed at the pressing position P of patterns 9 to 11 were calculated. The pressing position P of pattern 9 is located on the -X direction side of the concave portions of the substrate 110 and the top panel 130, as shown in FIG. 5A. The pressing position P of pattern 10 is located on the +X direction side of the concave portions of the substrate 110 and the top panel 130, as shown in FIG. 5B. The pressing positions P of patterns 9 and 10 are at line-symmetrical positions with respect to a straight line passing through the center of gravity G and parallel to the Y-axis. The pressing position P of pattern 11 is on the -Y direction side of the concave portions of the substrate 110 and the top panel 130 and is located on the -Y direction side of the center of gravity G, as shown in FIG. 5C.

[0051] Furthermore, Figures 5A to 5C show the distribution of displacement of the top panel 130 in the -Z direction. The ranges with median displacements of 0.7 mm, 0.8 mm, 0.9 mm, and 1 mm are shown separately. These displacement values ​​were obtained through simulation.

[0052] As shown in Figures 5A to 5C, in the distribution of displacement of the top panel 130 in the -Z direction due to the pressing position P of patterns 9 to 11, it was confirmed that the displacement of the top panel 130 was greatest in the part that is close to the pressing position P and closest to the outer edge of the top panel 130 in a plan view, and the displacement was smallest in the part located on the opposite side in a plan view from the part with the greatest displacement.

[0053] Furthermore, it was confirmed that even in the area with the smallest displacement, there was displacement in the -Z direction. This indicates that when a pressing operation is performed on the top panel 130 within the support area where the four elastic supports 120 are positioned in a plan view, no part lifts up like a seesaw, and the entire top panel 130 is displaced in the -Z direction.

[0054] Figure 6 shows an example of the current value (mA) of the combined output signal of the four optical sensors 150 when pressing operations are performed in patterns 9 to 11. As shown in Figure 6, the current value of the combined output signal of the four optical sensors 150 when pressing operations are performed in patterns 9 and 10 is approximately 3 (mA) and is substantially constant, while the current value of the combined output signal of the four optical sensors 150 when pressing operations are performed in pattern 11 is approximately 3.2 (mA). Thus, the current values ​​of the combined output signal when pressing operations are performed at pressing positions P in patterns 9 to 11 are within a range that can be said to be substantially equal. Therefore, when pressing operations are performed at pressing positions P in patterns 9 to 11, it is possible to determine whether or not a pressing operation has been performed using a single threshold.

[0055] <Arrangement of multiple optical sensors 150 relative to the center of gravity G> Figures 7A to 7C show an example of the arrangement of multiple optical sensors 150 relative to the center of gravity G in the input device 100.

[0056] As shown in Figures 3A to 3H and 4, it has been confirmed that by arranging multiple optical sensors 150 on a single circle centered on the centroid G, the current value of the combined output signal of the four optical sensors 150 can be kept approximately constant.

[0057] Figure 7A shows an input device 100 in which the substrate 110, four elastic supports 120, top panel 130, and four optical sensors 150 are arranged in the same manner as in Figures 3A to 3H. The dashed circle represents a single circle centered on the centroid G. In Figure 7A, the four optical sensors 150 are arranged on a single circle centered on the centroid G. The double arrows shown between the four optical sensors 150 and the four elastic supports 120 indicate the distance between the closest optical sensors 150 and the four elastic supports 120; for example, the lengths of the four double arrows are equal. That is, the distances between the closest optical sensors 150 and the four elastic supports 120 are all equal. As explained using Figures 3A to 3H and Figure 4, with this arrangement, when a pressing operation is performed at the pressing position P within the support area where the four elastic supports 120 are arranged, the current values ​​of the composite output signals will be approximately equal.

[0058] In other words, the arrangement of the four elastic supports 120 and the four optical sensors 150 is as follows:

[0059] The four optical sensors 150 include a first optical sensor 150 and a second optical sensor 150, and the multiple elastic supports 120 include a first elastic support 120 closest to the first optical sensor 150 and a second elastic support 120 closest to the second optical sensor 150. The four optical sensors 150 and the four elastic supports 120 are arranged such that a first distance between the first optical sensor 150 and the first elastic support 120 is equal to a second distance between the second optical sensor 150 and the second elastic support 120.

[0060] The first and second optical sensors 150 are any two of the four optical sensors 150, and the first elastic support 120 is the elastic support 120 closest to the first optical sensor 150 among the four elastic supports 120. The second elastic support 120 is the elastic support 120 closest to the second optical sensor 150 among the four elastic supports 120. The four elastic supports 120 are arranged such that the first distance between the first optical sensor 150 and the first elastic support 120 is equal to the second distance between the second optical sensor 150 and the second elastic support 120.

[0061] The distance between the closest of the four optical sensors 150 and the four elastic supports 120 may be, for example, the distance between the centers or centroids of the closest optical sensor 150 and elastic support 120, or the shortest distance between the outer edges of the closest optical sensor 150 and elastic support 120. Here, we will describe four optical sensors 150 and four elastic supports 120, but the same applies to multiple optical sensors 150 and the same number of elastic supports 120 as the optical sensors 150. Furthermore, the same applies even if the number of multiple optical sensors 150 and multiple elastic supports 120 are not the same.

[0062] Figure 7B shows an input device 100 with an irregularly shaped substrate 110, three elastic supports 120, a top panel 130 that is the same shape as the substrate 110 in plan view, and three optical sensors 150. The dashed circle is a single circle centered on the centroid G. In Figure 7B, the three elastic supports 120 are positioned near the outer edges of the irregularly shaped pentagonal substrate 110 and top panel 130. The three elastic supports 120 are arranged to form a triangle near the outer edges of the irregularly shaped pentagonal substrate 110 and top panel 130. The centroid G of the three elastic supports 120 is located near the center in the plan view of the irregularly shaped pentagonal substrate 110 and top panel 130.

[0063] The three optical sensors 150 are arranged on a single circle centered on the center of gravity G. The double arrows indicating the distance between the three optical sensors 150 and the three elastic supports 120 represent the distance between the closest optical sensors 150 and the three elastic supports 120, and the lengths of the three double arrows are equal. That is, the distance between the closest optical sensors 150 and the three elastic supports 120 is equal for all of them. With this arrangement, when a pressing operation is performed at the pressing position P within the support area where the three elastic supports 120 are located, the current values ​​of the combined output signals will be approximately equal, similar to the input device 100 shown in Figure 7A.

[0064] The input device 100 shown in Figure 7C has a configuration in which the position of the elastic support 120 located furthest towards the +Y direction is shifted towards the -Y direction compared to the input device 100 shown in Figure 7B. Therefore, the center of gravity of the three elastic supports 120 is shifted towards the -Y direction compared to the center of gravity G of the input device 100 shown in Figure 7B.

[0065] The three optical sensors 150 are arranged on a single circle centered on the center of gravity G. The double arrows shown between the three optical sensors 150 and the three elastic supports 120 indicate the distance between the closest optical sensors 150 and the three elastic supports 120, and the lengths of the three double arrows are equal. That is, the distance between the closest optical sensors 150 and the three elastic supports 120 is equal for all of them. With this arrangement, when a pressing operation is performed at the pressing position P within the support area where the three elastic supports 120 are located, the current values ​​of the combined output signals will be approximately equal, similar to the input device 100 shown in Figure 7B.

[0066] <Linear arrangement of elastic support 120, pressing positions P1, P2, optical sensor 150, and center of gravity G> Figure 8A shows an example of a linear arrangement of the elastic support 120, pressing positions P1, P2, optical sensor 150, and center of gravity G. Pressing positions P1 and P2 are the positions where two operating parts 131 (see Figure 1) are provided, respectively. Here, we will describe them as pressing positions P1 and P2, but they are synonymous with the positions where two operating parts 131 are provided.

[0067] Figure 8A shows four elastic supports 120 positioned at the four corners of a rectangular substrate 110. It also shows a straight line C connecting the centers of two elastic supports 120 positioned at the corners on the -X and +Y sides of the rectangular substrate 110, and the corners on the +X and -Y sides, in a plan view. The center of gravity G is located at the center of the substrate 110 in a plan view.

[0068] In the input device 100 shown in Figure 8A, the following are arranged in the order of pressing position P1, optical sensor 150, center of gravity G, optical sensor 150, and pressing position P2 between the elastic support 120 located at the corner on the -X and +Y sides and the elastic support 120 located at the corner on the +X and -Y sides. The elastic support 120, pressing positions P1 and P2, optical sensor 150, and center of gravity G are arranged on a straight line C. Operating parts 131 are provided at pressing positions P1 and P2. On the straight line C, both ends are two elastic support 120s.

[0069] The elastic support 120, pressing positions P1, P2, optical sensor 150, and center of gravity G are said to be arranged on a straight line C, which means that any part of the elastic support 120, pressing positions P1, P2, and optical sensor 150 in a plan view and the center of gravity G are arranged on a straight line C. As an example, it is preferable that the center of gravity or center of the elastic support 120, pressing positions P1, P2, and optical sensor 150 in a plan view and the center of gravity G are arranged on a straight line C.

[0070] In this way, by arranging the elastic support 120, pressing positions P1 and P2, the optical sensor 150, and the center of gravity G on the straight line C connecting the two elastic support 120, the amount of displacement of the top panel 130 in the -Z direction due to the pressing operation at pressing positions P1 and P2 is reflected as a larger amount of variation in the grayscale value obtained by converting the output signal of the operational amplifier of the inverting amplifier circuit to 12 bits. This makes it easier to determine whether or not a pressing operation has been performed. In particular, by arranging the optical sensor 150 between the center of gravity G and pressing positions P1 and P2, a large amount of change in the grayscale value can be obtained due to the pressing operation, making it easier to determine whether or not a pressing operation has been performed.

[0071] Furthermore, the distances between the center of gravity G, the two optical sensors 150, and the pressing positions P1 and P2 may be equal to the distance between the pressing position P1 and the optical sensor 150 on the -X side, the distance between the optical sensor 150 on the -X side and the center of gravity G, the distance between the center of gravity G and the optical sensor 150 on the +X side, and the distance between the optical sensor 150 on the +X side and the pressing position P2. In other words, the two optical sensors 150 may be located at the midpoint between the center of gravity G and the pressing positions P1 and P2.

[0072] For each of these distances, the distances between the optical sensor 150 and the pressing positions P1 and P2 can be set using the centroid or center in a plan view as the reference point for the distance.

[0073] Furthermore, the distance between the center of gravity G, the optical sensor 150, and the pressing positions P1 and P2 may reflect the distribution of displacement of the top panel 130 in the -Z direction when pressing positions P1 and P2 are pressed with a constant load.

[0074] Furthermore, the distance between the center of gravity G, the optical sensor 150, and the pressing positions P1 and P2 may reflect the ratio of the displacement of the top panel 130 in the -Z direction when pressing positions P1 and P2 with a constant load.

[0075] For example, when pressing position P1, the center of gravity G, and pressing position P2 of the operating surface 130A with a constant load, if the ratio of the displacement amounts in the -Z direction at the pressing positions of the top panel 130 is 1:3:2, then the following can be done: For the optical sensor 150 located between the elastic support 120 on the -X and +Y sides and the pressing position P1, the optical sensor 150 is moved closer to the elastic support 120 on the -X and +Y sides to obtain a larger displacement. Also, for the optical sensor 150 located between the elastic support 120 on the +X and -Y sides and the pressing position P2, the optical sensor 150 is moved further away from the elastic support 120 on the +X and -Y sides to reduce the displacement. By doing so, the current values ​​of the combined output signal when pressing operations are performed at pressing positions P1 and P2 can be equalized.

[0076] <Placement of the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G> Figure 8B shows an example of the placement of the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G. The operating area surrounded by two adjacent pressing positions P and the center of gravity G is the area connected to either part of the two adjacent pressing positions P in a plan view and the center of gravity G.

[0077] In the input device 100 shown in Figure 8B, four elastic supports 120 are positioned at the four corners of the rectangular substrate 110. Therefore, the center of gravity G is located at the center of the substrate 110 in a plan view.

[0078] In the input device 100 shown in Figure 8B, four pressing positions P1 to P4 are provided between the four elastic supports 120 and the center of gravity G. Pressing positions P1 to P4 are the positions where four operating parts 131 (see Figure 1) are provided. Here, we will refer to them as pressing positions P1 to P4, but they are synonymous with the positions where the four operating parts 131 are provided. The centers of pressing positions P1 to P4 in a plan view are all located on a straight line connecting the centers of the four elastic supports 120 in a plan view and the center of gravity G. When the four pressing positions P1 to P4 are not specifically distinguished, they are simply referred to as pressing position P.

[0079] In this arrangement, it is preferable to place the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G. More specifically, the optical sensor 150 located on the -X side of the center of gravity G is placed within the first operating area surrounded by two adjacent pressing positions P1 and P3 and the center of gravity G. The optical sensor 150 located on the +Y side of the center of gravity G is placed within the second operating area surrounded by two adjacent pressing positions P1 and P2 and the center of gravity G. The optical sensor 150 located on the +X side of the center of gravity G is placed within the third operating area surrounded by two adjacent pressing positions P2 and P4 and the center of gravity G. The optical sensor 150 located on the -Y side of the center of gravity G is placed within the fourth operating area surrounded by two adjacent pressing positions P3 and P4 and the center of gravity G.

[0080] In this way, by arranging the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G, the pressing positions P are located closer to the elastic support 120 than the center of gravity. Therefore, regardless of which pressing position P is used for the pressing operation, a certain amount of displacement in the -Z direction can be obtained in the top panel 130. Furthermore, by arranging the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G, a certain amount of displacement in the -Z direction can be detected by the optical sensor 150 regardless of which pressing position P is used for the pressing operation. As a result, the amount of variation due to the pressing operation in the converted value obtained by converting the output signal of the operational amplifier in the inverting amplifier circuit, which amplifies the combined output signal obtained by combining the output signals of multiple optical sensors 150, into a 12-bit grayscale value becomes larger, making it easier to determine whether or not a pressing operation has been performed.

[0081] The distances of the parts indicated by the multiple double-headed arrows in Figure 8B should be set to move closer to or further away from the center of gravity G, depending on the distribution of the displacement of the top panel 130 in the -Z direction when each of the pressing positions P1 to P4 is pressed with a constant load. The distances of the parts indicated by the multiple double-headed arrows in Figure 8B are the distance in the X or Y direction between the center of gravity G and the center of the optical sensor 150, and the distance in the X or Y direction between the optical sensor 150 and the pressing position P.

[0082] Figure 8C shows another example of the arrangement of the optical sensor 150 within the operating area surrounded by two adjacent pressing positions P and the center of gravity G. Figure 8C shows the configuration when the substrate 110 and top panel 130 are of a different shape, similar to the substrate 110 and top panel 130 shown in Figures 5A to 5C.

[0083] The input device 100 shown in Figure 8C includes five elastic supports 120, five pressing positions P1 to P5, and four optical sensors 150, but as in Figure 8B, each optical sensor 150 is arranged within an operating area surrounded by two adjacent pressing positions P and the center of gravity G.

[0084] Furthermore, the distances between the parts represented by the multiple double-headed arrows shown in Figure 8C should be set to move closer to or further away from the center of gravity G, depending on the distribution of the displacement of the top panel 130 in the -Z direction when each of the pressing positions P1 to P5 is pressed with a constant load, similar to the distances between the parts represented by the multiple double-headed arrows shown in Figure 8B.

[0085] <Circuit Configuration> Figure 9 shows the circuit configuration of the input device 100. Figure 9 shows the circuit configuration of the part of the input device 100 that determines whether or not a pressing operation has been performed based on the output signal of the optical sensor 150, while the circuit configuration of the part that determines which operation unit 131 is being operated on based on the output signal of the electrostatic sensor 140 is omitted.

[0086] Figure 9 shows four light sensors 150 as an example, corresponding to Figure 1. In Figure 9, each light sensor 150 is shown as a circuit composed of a light-emitting diode (light-emitting part) and a light-receiving element (light-receiving part). The output terminal 151A of the light-receiving part of each light sensor 150 is the output terminal of each light sensor 150.

[0087] In addition to the components shown in Figure 1, the input device 100 includes a wired-or connection section 155, a scale change section 160, and an MCU 170, as shown in Figure 9. The wired-or connection section 155 is an example of an output combining section. The wired-or connection section 155, the scale change section 160, and the MCU 170 may be provided on the substrate 110 (see Figures 1 and 2), or on a substrate other than the substrate 110.

[0088] <Wired-OR connection section 155> The wired-OR connection section 155 has four wires 155A connected to the output terminals 151A of the light receiving sections of the four light sensors 150, and a connection point 155B that connects the four wires 155A. Since the connection point 155B connects the four wires 155A, the wired-OR connection section 155 connects the output terminals 151A of the light receiving sections of the four light sensors 150 in a wired-OR format and outputs a combined output signal which is a composite of the output signals of the light receiving sections of the four light sensors 150. In addition, the connection point 155B also serves as an output terminal of the wired-OR connection section 155.

[0089] The connection point 155B of the wired-OR connection section 155 is connected to the inverting input terminal of the operational amplifier 161A of the inverting amplifier circuit 161. As described above with reference to Figure 1, the four optical sensors 150 are arranged within the support area where the four elastic supports 120 are positioned in a plan view. Therefore, no matter which part of the operating surface 130A is pressed in the -Z direction, the combined output signal synthesized at the connection point 155B will always increase. Furthermore, since the output terminals 151A of the four optical sensors 150 are connected in a wired-OR format outside the MCU 170, the circuit configuration and the configuration of the MCU 170 can be simplified compared to a circuit configuration in which the four optical sensors 150 are connected to the MCU 170.

[0090] In this embodiment, as an example, a configuration in which multiple optical sensors 150 are used as multiple displacement detection units, and the output terminals 151A of the multiple optical sensors 150 are connected in a wired-OR manner outside the MCU 170 will be described. However, multiple strain sensors may be used as multiple displacement detection units. The output terminals of the multiple strain sensors may be connected in a wired-OR manner to detect the displacement of the top panel 130 in the -Z direction. Alternatively, in this case, the displacement of the top panel 130 in the -Z direction may be detected by detecting the deformation of the multiple elastic supports 120. The multiple displacement detection units can be sensors that are capable of detecting the displacement of the top panel 130 in the -Z direction and have output terminals that can be connected in a wired-OR manner.

[0091] <Scale Change Unit 160> The scale change unit 160 includes an inverting amplifier circuit 161 and a reference voltage output unit 162. The scale change unit 160 changes the scale of the output signal of the operational amplifier 161A in order to make it easier for the control unit 172 of the MCU 170 to more accurately determine whether or not a pressing operation has been performed based on the output signal of the operational amplifier 161A. More specifically, the control unit 172 controls the degree to which the scale of the output signal of the operational amplifier 161A is changed in the scale change unit 160 by changing the reference voltage output by the reference voltage output unit 162. Details of the operation of the scale change unit 160 will be described later. Changing the scale of the output signal of the operational amplifier 161A means changing the range of the output signal of the operational amplifier 161A.

[0092] The inverting amplifier circuit 161 includes an operational amplifier 161A, an input resistor R6, and a feedback resistor R9. The inverting input terminal of the operational amplifier 161A is connected to connection point 155B, which is the output terminal of the wired-or connection unit 155, via the input resistor R6. The non-inverting input terminal of the operational amplifier 161A is connected to a reference voltage output unit 162. The output terminal of the operational amplifier 161A outputs an output signal, which is input to the MCU 170.

[0093] The reference voltage output unit 162 is, for example, a switching voltage regulator, and changes the reference voltage output to the non-inverting input terminal of the operational amplifier 161A in accordance with the PWM (Pulse Width Modulation) type change signal output from the change signal output unit 173 of the MCU 170. Here, as an example, a configuration in which the reference voltage output unit 162 is a switching voltage regulator is described, but the reference voltage output unit 162 may also be a voltage regulator that changes the reference voltage output to the non-inverting input terminal based on an analog change signal or a PWM type change signal output from the change signal output unit 173 of the MCU 170.

[0094] <MCU170> The MCU170 includes an ADC (Analog to Digital Converter) 171, a control unit 172, and a modified signal output unit 173. The MCU170 is composed of an IC (Integrated Circuit).

[0095] The ADC 171 is connected to the output terminal of the operational amplifier 161A, and receives the output signal from the operational amplifier 161A as input. The ADC 171 digitally converts the output signal from the operational amplifier 161A and outputs it to the control unit 172.

[0096] The control unit 172 is connected to the ADC 171 and the change signal output unit 173. The control unit 172 is implemented by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output interface, and internal bus. The control unit 172 receives a converted value from the ADC 171, which is obtained by converting the output signal of the operational amplifier 161A into a 12-bit grayscale value.

[0097] The control unit 172 determines whether or not a pressing operation is performed on the top panel 130 based on the converted value input from the ADC 171. Since the output signal of the operational amplifier 161A is a signal corresponding to the combined output signal input to the inverting input terminal of the operational amplifier 161A, the control unit 172 determining whether or not a pressing operation is performed on the top panel 130 based on the converted value input from the ADC 171 is equivalent to determining whether or not a pressing operation is performed on the top panel 130 based on the combined output signal generated by the wired OR connection unit 155.

[0098] Furthermore, when the control unit 172 determines whether or not a pressing operation has been performed on the top panel 130, it causes the change signal output unit 173 to output a change signal based on the output signal of the operational amplifier 161A, thereby changing the reference voltage output by the reference voltage output unit 162. By changing the reference voltage output by the reference voltage output unit 162, the control unit 172 controls the degree of scale change of the output signal of the operational amplifier 161A in the scale change unit 160. Details of this will be described later.

[0099] Furthermore, when the control unit 172 controls the degree of scale change of the output signal of the operational amplifier 161A, it controls the reference voltage so that the converted value obtained by converting the output signal of the operational amplifier 161A into a 12-bit grayscale value falls between the first grayscale value (1000 LSB) and the second grayscale value (3700 LSB). 12 bits is an example of a predetermined number of bits. Details of this will be described later.

[0100] Although the specific circuit configuration is omitted in Figure 9, the control unit 172 calculates the XY coordinates of the position where the fingertip FT is touching the operating surface 130A based on the output signal of the electrostatic sensor 140, and determines which operating unit 131 is being operated on.

[0101] <Changing the current value of the combined output signal and the scale of the output signal of the operational amplifier 161> Figure 10 is a characteristic diagram showing an example of the relationship between the gap detected by the optical sensor 150 and the current value of the combined output signal.

[0102] In Figure 10, the horizontal axis represents the gap (mm) detected by the optical sensor 150. The gap detected by the optical sensor 150 is the distance in the Z direction between the light-receiving part 151 and the reflector 152 of the optical sensor 150. In Figure 10, the vertical axis represents the current value (mA) of the combined output signal.

[0103] Due to variations in the dimensions of each component of the input device 100, for example, the minimum value of the gap is 1.00 mm and the maximum value of the gap is 2.00 mm. When a pressing operation is performed on the operating surface 130A of the top panel 130, the top panel 130 is displaced by about 0.1 mm in the -Z direction.

[0104] Furthermore, due to differences in the signal level of the output signal depending on the type of optical sensor 150, variations in the optical characteristics of the optical sensor 150, or the ambient temperature where the input device 100 is placed, the current value of the combined output signal can take on a range from the maximum value shown by the dashed line to the minimum value shown by the dashed line. Figure 10 shows the characteristics of the median value of the combined output signal current value with a solid line.

[0105] The control unit 172 of the MCU 170 converts the combined output voltage value obtained by converting the combined output signal into a voltage value, and the output signal of the operational amplifier 161A, which is output according to the voltage difference between the combined output voltage value and the reference voltage, into a 12-bit, 4096-level value (value from 0 LSB to 4095 LSB) (converted value). Then, the control unit 172 determines that a pressing operation has been performed when the converted value exceeds a threshold value for determining a pressing operation (for example, 3000 LSB).

[0106] Incidentally, when the current value of the combined output signal takes its minimum value, and the gap is 2.00 mm when no pressing operation is performed (initial state), and the gap is 1.90 mm when pressing operation is performed, the change in the current value of the combined output signal due to the pressing operation is smallest.

[0107] Even in this state, in order to accurately determine whether or not a pressing operation has been performed, the input device 100 divides the combined output signal into five areas (areas 1 to 5) according to the current value of the combined output signal, as shown in Figure 10, and sets an appropriate reference voltage in each area so that the scale with respect to the combined output signal is as large as possible. This control is achieved by the control unit 172 changing the duty cycle of the modified signal output unit 173 based on the output signal of the operational amplifier 161A. The reference voltage output unit 162, to which the modified signal is input from the modified signal output unit 173, is a circuit that drives a switching voltage regulator with PWM. The modified signal is a command signal for changing the reference voltage of the operational amplifier 161A, and is a signal that sets the duty cycle when the reference voltage output unit 162 generates the reference voltage.

[0108] <Switching process for areas 1 to 5> Figure 11 is a diagram illustrating an example of the switching process for areas 1 to 5. In Figure 11, the horizontal axis represents the current value (mA) of the combined output signal, and the vertical axis represents the converted value (0 LSB to 4095 LSB) obtained by converting the output signal of the operational amplifier 161A to 12 bits.

[0109] Furthermore, in Figure 11, the shaded lines (1) to (5) indicate the characteristics of the converted value obtained by converting the minimum current value of the composite output signal in areas 1 to 5 in Figure 10 to 12 bits, with respect to the current value of the composite output signal.

[0110] Figure 11 also shows the lower threshold (1000 LSB) and the upper threshold (3700 LSB) when switching between areas 1 to 5. When the control unit 172 controls the degree of change in the scale of the output signal of the operational amplifier 161A, it controls the reference voltage so that the converted value of the output signal of the operational amplifier 161A falls between 1000 LSB (first grayscale value) and 3700 LSB (second grayscale value).

[0111] For example, when the output of the reference voltage output unit 162 is set to the reference voltage of area 1, the combined output signal decreases from approximately 2.4 (mA) to approximately 1.75 (mA), and when the converted value increases along characteristic (1) to 3700 LSB or more, the system switches from area 1 to area 2 and transitions to point (2A) of characteristic (2). By switching from area 1 to area 2 in this way, the scale of the output signal of the operational amplifier 161A with respect to the converted value is expanded. Expanding the scale of the converted value (the vertical axis scale in Figure 11) means that the range of converted values ​​smaller than the range of converted values ​​that were converted to 12 bits (4096 gradations) before the scale expansion is expanded and can be represented by 12 bits.

[0112] When the combined output signal is between approximately 1.35 mA and 2.05 mA, it is set to the reference voltage of area 2, and the converted value changes according to characteristic (2). When the combined output signal drops to approximately 1.35 mA and the converted value increases according to characteristic (2) to 3700 LSB or more, the system switches from area 2 to area 3 and transitions to point (3A) of characteristic (3). By switching from area 2 to area 3 in this way, the scale of the output signal of the operational amplifier 161A with respect to the converted value is expanded.

[0113] When the combined output signal is between approximately 0.92 mA and approximately 1.62 mA, it is set to the reference voltage of area 3, and the converted value changes according to characteristic (3). When the combined output signal drops to approximately 0.92 mA and the converted value increases according to characteristic (3) to 3700 LSB or more, the system switches from area 3 to area 4 and transitions to point (4A) of characteristic (4). By switching from area 3 to area 4 in this way, the scale of the conversion value of the output signal of the operational amplifier 161A is expanded.

[0114] When the combined output signal is between approximately 0.52 mA and approximately 1.22 mA, it is set to the reference voltage of area 4, and the converted value changes according to characteristic (4). When the combined output signal drops to approximately 0.52 mA and the converted value increases according to characteristic (4) to 3700 LSB or more, the system switches from area 4 to area 5 and transitions to point (5A) of characteristic (5). By switching from area 4 to area 5 in this way, the scale of the output signal of the operational amplifier 161A with respect to the converted value is expanded.

[0115] When the combined output signal is between approximately 0.24 mA and approximately 0.83 mA, it is set to the reference voltage of area 5, and the converted value changes according to characteristic (5). When the combined output signal increases to approximately 0.83 mA and the converted value decreases according to characteristic (5) to 1000 LSB or less, the system switches from area 5 to area 4 and transitions to point (4B) of characteristic (4). By switching from area 5 to area 4 in this way, the scale of the output signal of the op-amp 161A with respect to the converted value is reduced. The reduction in the scale of the converted value (the vertical axis scale in Figure 11) means that the range of converted values ​​larger than the range of converted values ​​that were converted to 12 bits (4096 gradations) before the scale reduction is reduced, and the range is represented by 12 bits.

[0116] Furthermore, when the reference voltage is set to Area 4, the combined output signal increases to approximately 1.22 mA, and when the conversion value decreases along characteristic (4) to 1000 LSB or less, the system switches from Area 4 to Area 3 and transitions to point (3B) of characteristic (3). This switching from Area 4 to Area 3 reduces the scale of the output signal of the operational amplifier 161A relative to the conversion value.

[0117] Furthermore, when the reference voltage is set to Area 3, the combined output signal increases to approximately 1.62 mA, and when the conversion value decreases along characteristic (3) to 1000 LSB or less, the system switches from Area 3 to Area 2 and transitions to point (2B) of characteristic (2). This switching from Area 3 to Area 2 reduces the scale of the output signal of the operational amplifier 161A relative to the conversion value.

[0118] Furthermore, when the reference voltage is set to Area 2, the combined output signal increases to approximately 2.05 (mA), and when the conversion value decreases along characteristic (2) to 1000 LSB or less, the system switches from Area 2 to Area 1 and transitions to point (1B) of characteristic (1). This switching from Area 2 to Area 1 reduces the scale of the output signal of the operational amplifier 161A relative to the conversion value.

[0119] In this way, the control unit 172 controls the reference voltage according to areas 1 to 5, thereby changing (expanding or shrinking) the scale of the converted value of the output signal of the operational amplifier 161A, and controlling the converted value of the output signal of the operational amplifier 161A to fall between 1000 LSB (first grayscale value) and 3700 LSB (second grayscale value).

[0120] Note that in Figure 11, as an example, the explanation uses a converted value obtained by converting the minimum current value of the composite output signal to 12 bits. However, if the converted value is obtained by converting the median or maximum current value of the composite output signal to 12 bits, the switching process will be the same, only the value of the composite output signal will differ.

[0121] <Flowchart> Figure 12 is a flowchart showing an example of the reference voltage switching process performed by the control unit 172. The control unit 172 repeatedly performs the process shown in Figure 12 when it is not detecting the position of the fingertip FT based on the output of the electrostatic sensor 140.

[0122] When the control unit 172 starts processing, it sets the reference voltage to the reference voltage for area 1 (step S1). Setting the reference voltage means that the control unit 172 sets the duty cycle of the change signal output to the change signal output unit 173 to a duty cycle corresponding to the reference voltage for the desired area.

[0123] The control unit 172 acquires the converted value (the grayscale value obtained by digitally converting the output signal of the operational amplifier 161A) input from the ADC 171 (step S2).

[0124] The control unit 172 determines whether the converted value is 3700 LSB or more (step S3).

[0125] If the control unit 172 determines that the conversion value is not 3700 LSB or greater (S3: No), it returns the flow to step S2. Alternatively, if S3: No is determined, the flow may be returned to start and the reference voltage for area 1 may be set again.

[0126] If the control unit 172 determines in step S3 that the conversion value is 3700 LSB or more (S3: Yes), it sets the reference voltage to the reference voltage for area 2 (step S4).

[0127] The control unit 172 acquires the converted value input from the ADC 171 (step S5).

[0128] The control unit 172 determines whether the converted value is 3700 LSB or more (step S6).

[0129] If the control unit 172 determines that the converted value is not 3700 LSB or more (S6: No), it determines whether the converted value is 1000 LSB or less (step S7).

[0130] When the control unit 172 determines that the conversion value is 1000 LSB or less (S7: Yes), it returns the flow to step S1. This is to set the reference voltage for area 1.

[0131] If the control unit 172 determines in step S7 that the conversion value is not 1000 LSB or less (S7: No), it returns the flow to step S5. Alternatively, if it determines S7: No, it may return the flow to step S4 and set it again as the reference voltage for area 2.

[0132] If the control unit 172 determines in step S6 that the conversion value is 3700 LSB or more (S6: Yes), it sets the reference voltage to the reference voltage for area 3 (step S8).

[0133] The control unit 172 acquires the converted value input from the ADC 171 (step S9).

[0134] The control unit 172 determines whether the converted value is 3700 LSB or more (step S10).

[0135] If the control unit 172 determines that the conversion value is not 3700 LSB or more (S10: No), it determines whether the conversion value is 1000 LSB or less (step S11).

[0136] When the control unit 172 determines that the conversion value is 1000 LSB or less (S11: Yes), it returns the flow to step S4. This is to set the reference voltage for area 2.

[0137] If the control unit 172 determines in step S11 that the conversion value is not 1000 LSB or less (S11: No), it returns the flow to step S9. Alternatively, if it determines S11: No, it may return the flow to step S8 and set it again as the reference voltage for area 3.

[0138] If the control unit 172 determines in step S10 that the conversion value is 3700 LSB or more (S10: Yes), it sets the reference voltage to the reference voltage for area 4 (step S12).

[0139] The control unit 172 acquires the converted value input from the ADC 171 (step S13).

[0140] The control unit 172 determines whether the converted value is 3700 LSB or more (step S14).

[0141] If the control unit 172 determines that the converted value is not 3700 LSB or more (S14: No), it determines whether the converted value is 1000 LSB or less (step S15).

[0142] If the control unit 172 determines that the conversion value is 1000 LSB or less (S15: Yes), it returns the flow to step S8. This is to set the reference voltage for area 3.

[0143] If the control unit 172 determines in step S15 that the conversion value is not 1000 LSB or less (S15: No), it returns the flow to step S13. Alternatively, if it determines S15: No, it may return the flow to step S12 and set it again as the reference voltage for area 4.

[0144] If the control unit 172 determines in step S14 that the conversion value is 3700 LSB or more (S14: Yes), it sets the reference voltage to the reference voltage for area 5 (step S16).

[0145] The control unit 172 acquires the converted value input from the ADC 171 (step S17).

[0146] The control unit 172 determines whether the conversion value is 1000 LSB or less (step S18).

[0147] When the control unit 172 determines that the conversion value is 1000 LSB or less (S18: Yes), it returns the flow to step S12. This is to set the reference voltage for area 4.

[0148] If the control unit 172 determines in step S18 that the conversion value is not 1000 LSB or less (S18: No), it returns the flow to step S17. Alternatively, if it determines S18: No, it may return the flow to step S16 and set it again as the reference voltage for area 5.

[0149] <Timing Chart> Figure 13 is a timing chart showing an example of the operation of the input device 100. Figure 13 shows the state of the MCU 170 (Ready or Standby), the duty cycle of the change signal (Duty 1 to Duty 5), and the converted value of the output signal of the operational amplifier 161A. The horizontal axis (time axis) of Figure 13 is set to 0 ms when the state of the MCU 170 changes from Standby to Ready, and is shown in 10 ms increments.

[0150] Here, as an example, the control unit 172 acquires a converted value every 10 ms, and if the converted value acquired three times consecutively is 3700 LSB or more, it switches the duty cycle of the modified signal.

[0151] At time 0ms, the state of the MCU 170 changes from Standby to Ready. The control unit 172 sets the duty cycle of the change signal to Duty 1, which corresponds to the reference voltage of area 1.

[0152] The control unit 172 determines that the conversion values ​​acquired at times 10ms, 20ms, and 30ms are 3700 LSB or more, and therefore sets the duty cycle of the change signal to Duty 2, which corresponds to the reference voltage in area 2, at time 40ms.

[0153] The control unit 172 determines that the conversion values ​​acquired at times 50ms, 60ms, and 70ms are 3700 LSB or more, and therefore sets the duty cycle of the change signal to Duty 3, which corresponds to the reference voltage of area 3, at time 80ms.

[0154] The control unit 172 determines that the conversion values ​​acquired at times 90ms, 100ms, and 110ms are 3700 LSB or more, and therefore sets the duty cycle of the change signal to Duty 4, which corresponds to the reference voltage of area 4, at time 120ms.

[0155] The control unit 172 maintains the duty cycle of the modified signal at time 160ms at Duty 4, corresponding to the reference voltage of area 4, because the converted values ​​acquired at times 130ms, 140ms, and 150ms are less than 3700 LSB and greater than 1000 LSB.

[0156] In this way, the duty cycle of the change signal is set to Duty 4, which corresponds to the reference voltage in Area 4, and the conversion value is controlled within the range of 1000 LSB to 3700 LSB.

[0157] In the above description, the multiple optical sensors 150 are arranged in a configuration in which, when a pressing operation is performed within the support area of ​​the operating surface 130A in a plan view, the control unit 172 can determine whether or not a pressing operation has been performed on the operating surface 130A using a single determination threshold. However, if the control unit 172 outputs a modified signal to the modified signal output unit 173 having a duty cycle that can control the reference voltage so that the output signal of the operational amplifier 161A is binarized, the arrangement of the multiple optical sensors 150 does not have to be in a configuration in which the control unit 172 can determine whether or not a pressing operation has been performed using a single determination threshold.

[0158] The binarization of the output signal of the operational amplifier 161A means, for example, the following: that the current value of the output signal of the operational amplifier 161A when no pressing operation is performed is clearly different from the current value of the output signal of the operational amplifier 161A when one or more operating parts 131 of the operating surface 130A are pressed, and that the respective current values ​​when one or more operating parts 131 of the operating surface 130A are pressed are approximately equal.

[0159] <Effects> The input device 100 includes a top panel 130 having an operating surface 130A that can be pressed, a substrate 110 positioned opposite the top panel 130 in the pressing direction of the pressing operation on the top panel 130, a plurality of elastic supports 120 that support the top panel 130 with respect to the substrate 110 and are elastically deformable, a plurality of optical sensors 150 positioned within a support area where the plurality of elastic supports 120 are arranged in a plan view and detect the displacement of the top panel 130 due to the pressing operation on the operating surface 130A, an output combining unit that generates a combined output signal by combining the output signals of the plurality of optical sensors 150, and a control unit 172 that determines whether or not a pressing operation has been performed on the top panel 130 based on the combined output signal generated by the output combining unit. Therefore, a configuration can be achieved in which the combined output signal always increases when a pressing operation is performed.

[0160] Therefore, it is possible to provide an input device 100 that can correctly determine the pressing operation.

[0161] Furthermore, the multiple optical sensors 150 may be positioned so that the control unit 172 can determine whether or not a pressing operation has been performed on the operating surface 130A using a single determination threshold when a pressing operation is performed within the support area of ​​the operating surface 130A in a plan view. By enabling the control unit 172 to determine whether or not a pressing operation has been performed on the operating surface 130A using a single determination threshold, the load on the control unit 172 when performing the determination process is reduced, which can simplify the configuration of the MCU 170 and reduce costs.

[0162] Furthermore, the positions in which the multiple optical sensors 150 are arranged may be positions in which they are arranged concentrically with respect to the center of gravity G or the center of the multiple elastic supports 120 in a plan view. By arranging the multiple optical sensors 150 concentrically with respect to the center of gravity G or the center of the multiple elastic supports 120, the signal level (current value) of the composite output signal is equalized when a pressing operation is performed at various positions on the operating surface 130A, making it easier to more accurately determine whether or not a pressing operation has been performed.

[0163] Furthermore, the plurality of optical sensors 150 may include a first optical sensor 150 and a second optical sensor 150, and the plurality of elastic supports 120 may include a first elastic support 120 closest to the first optical sensor 150 and a second elastic support 120 closest to the second optical sensor 150, and the plurality of optical sensors 150 and the plurality of elastic supports 120 may be arranged such that a first distance between the first optical sensor 150 and the first elastic support 120 is equal to a second distance between the second optical sensor 150 and the second elastic support 120. When a pressing operation is performed, the displacement of the top panel 130 in the -Z direction at the location of the elastic support 120 in a plan view is maximized. With this arrangement, when a pressing operation is performed at various positions on the operating surface 130A, the signal level (current value) of the composite output signal is equalized, making it easier to more accurately determine whether or not a pressing operation has been performed.

[0164] Furthermore, the top panel 130 is further provided with an electrostatic sensor 140 on the opposing surface 130B facing the substrate 110, and the operating surface 130A is provided with a plurality of operating parts 131 at positions that overlap with the electrostatic sensor 140 in a plan view, and the plurality of operating parts 131 may be located in a support area in a plan view where a plurality of elastic supports 120 are arranged. Since the pressing operation is performed within the support area where the plurality of elastic supports 120 are arranged in a plan view, a configuration in which the combined output signal always increases when a pressing operation is performed can be more reliably realized, and an input device 100 that can more accurately determine the pressing operation can be provided.

[0165] Furthermore, the device is further equipped with an electrostatic sensor 140 on the opposing surface 130B of the top panel 130 facing the substrate 110, and the operating surface 130A is provided with a plurality of operating parts 131 at positions that overlap with the electrostatic sensor 140 in a plan view, and each of the plurality of optical sensors 150 may be located in an operating area surrounded by two adjacent operating parts 131 and the center of gravity G or center of the plurality of elastic supports 120 in a plan view. By arranging the optical sensors 150 in an operating area surrounded by two adjacent operating parts 131 and the center of gravity G, the optical sensors 150 can detect a certain amount of displacement in the -Z direction regardless of which operating part 131 is subjected to a pressing operation. As a result, the amount of variation due to the pressing operation in the converted value obtained by converting the output signal of the operational amplifier 161A into a 12-bit grayscale value becomes larger, making it easier to determine whether or not a pressing operation has been performed.

[0166] Furthermore, the control unit 172 may further include an inverting amplifier circuit 161 having an operational amplifier 161A having an inverting input terminal to which a combined output signal is input, and a reference voltage output unit 162 that outputs a reference voltage to the non-inverting input terminal of the operational amplifier 161A in a changeable manner, and a scale changing unit 160 that changes the scale of the output signal of the operational amplifier 161A, and the control unit 172 may determine whether or not a pressing operation has been performed on the top panel 130 based on the output signal of the operational amplifier 161A. By changing the scale of the output signal of the operational amplifier 161A, it is possible to determine whether or not a pressing operation has been performed more accurately.

[0167] Furthermore, the output combining unit is a wired-or connection unit that connects the output terminals of multiple optical sensors 150 in a wired-or format and has an output terminal that outputs a combined output signal. The multiple displacement detection units are multiple reflective optical sensors 150 provided on the substrate 110. The output terminal of the wired-or connection unit is connected to the inverting input terminal of the operational amplifier 161A, so that the combined output signal is input to the inverting input terminal. The control unit 172 may control the degree of scale change of the output signal of the operational amplifier 161A in the scale changing unit 160 by changing the reference voltage output by the reference voltage output unit 162 based on the output signal of the operational amplifier 161A. Since the scale of the output signal is changed based on the output signal output from the operational amplifier 161A based on the combined output signal generated in a wired-or format, it is possible to determine whether or not a pressing operation is performed while the fluctuation of the output signal is amplified, and an input device 100 that can determine the pressing operation more accurately can be provided.

[0168] Furthermore, the control unit 172 may control the reference voltage so that the converted value obtained by converting the output signal of the operational amplifier 161A into a predetermined bit gradation value falls between the first gradation value and a second gradation value that is greater than the first gradation value. By ensuring that the converted value falls between the first and second gradation values ​​and amplifying the variation in the output signal, it is possible to provide an input device 100 that can determine whether or not a pressing operation has been performed, thereby enabling more accurate determination of the pressing operation.

[0169] Furthermore, the scale changing unit 160 includes an inverting amplifier circuit 161 that includes an operational amplifier 161A having an inverting input terminal to which a combined output signal is input, and a reference voltage output unit 162 that outputs a reference voltage to the non-inverting input terminal of the operational amplifier 161A in a changeable manner, and further comprises a scale changing unit 160 that changes the scale of the output signal of the operational amplifier 161A, and the output combining unit is a wired-or connection unit 155 that connects the output terminals 151A of a plurality of displacement detection units in a wired-or format and has an output terminal (connection point 155B) that outputs a combined output signal, the plurality of displacement detection units are a plurality of reflective light sensors 150 provided on the substrate, and the control unit 172 may control the reference voltage input to the non-inverting input terminal of the operational amplifier 161A so that the output of the operational amplifier 161A is binarized. By binarizing the output signal of the operational amplifier 161A, it is possible to determine the presence or absence of a pressing operation more accurately and easily.

[0170] Although an exemplary embodiment of an input device of this disclosure has been described above, this disclosure is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0171] This international application claims priority based on Japanese Patent Application No. 2024-196744, filed on November 11, 2024, the entire contents of which are incorporated herein by reference.

[0172] 100 Input device 110 Circuit board 120 Elastic support 130 Top panel (example of operation panel) 130A Operation surface 130B Opposing surface 131 Operation section 140 Electrostatic sensor 150 Optical sensor (example of displacement detection section) 151 Light receiving / emitting section 151A Output terminal 152 Reflector 155 Wired OR connection section (example of output combining section) 155A Wiring 155B Connection point 160 Scale change section 161 Inverting amplifier circuit 161A Operation amplifier 162 Reference voltage output section 171 ADC 172 Control section 173 Changed signal output section

Claims

1. An input device comprising: an operating panel having an operating surface that can be pressed; a substrate positioned opposite to the operating panel in the direction of pressing the operating panel; a plurality of elastic supports that support the operating panel with respect to the substrate and are elastically deformable; a plurality of displacement detection units positioned within a support region where the plurality of elastic supports are arranged in a plan view, for detecting the displacement of the operating panel due to pressing the operating surface; an output combining unit that generates a combined output signal by combining the output signals of the plurality of displacement detection units; and a control unit that determines whether or not pressing is performed on the operating panel based on the combined output signal generated by the output combining unit.

2. The input device according to claim 1, wherein the plurality of displacement detection units are positioned so that the control unit can determine whether or not a pressing operation is performed on the operating surface using a single determination threshold when a pressing operation is performed within the support area of ​​the operating surface in a plan view.

3. The input device according to claim 2, wherein the positions where the plurality of displacement detection units are arranged are, in a plan view, positions arranged concentrically with respect to the center of gravity or center of the plurality of elastic supports.

4. The input device according to claim 2 or 3, wherein the plurality of displacement detection units include a first displacement detection unit and a second displacement detection unit, the plurality of elastic supports include a first elastic support closest to the first displacement detection unit and a second elastic support closest to the second displacement detection unit, and the plurality of displacement detection units and the plurality of elastic supports are arranged such that a first distance between the first displacement detection unit and the first elastic support is equal to a second distance between the second displacement detection unit and the second elastic support.

5. The input device according to any one of claims 2 to 4, further comprising an electrostatic sensor provided on the opposing surface of the operation panel facing the substrate, wherein a plurality of operating parts are provided on the operation surface at positions that overlap with the electrostatic sensor in a plan view, and the plurality of operating parts are located within the support area in a plan view.

6. The input device according to any one of claims 2 to 4, further comprising an electrostatic sensor provided on the surface of the operation panel facing the substrate, wherein a plurality of operation units are provided on the operation surface at positions that overlap with the electrostatic sensor in a plan view, and each of the plurality of displacement detection units is located in a plan view within an operation unit region surrounded by two adjacent operation units among the plurality of operation units and the center of gravity or center of the plurality of elastic supports.

7. An input device according to any one of claims 1 to 6, comprising: an inverting amplifier circuit including an operational amplifier having an inverting input terminal to which the combined output signal is input; a reference voltage output unit that outputs a reference voltage to the non-inverting input terminal of the operational amplifier in a changeable manner; and further comprising a scale changing unit that changes the scale of the output signal of the operational amplifier, wherein the control unit determines whether or not a pressing operation has been performed on the operation panel based on the output signal of the operational amplifier.

8. The input device according to claim 7, wherein the output combining unit is a wired-or connection unit having an output terminal that connects the output terminals of the plurality of displacement detection units in a wired-or format and outputs the combined output signal, the plurality of displacement detection units are a plurality of reflective light sensors provided on the substrate, the output terminal of the wired-or connection unit is connected to the inverting input terminal of the operational amplifier so that the combined output signal is input to the inverting input terminal, and the control unit controls the degree of scale change of the output signal of the operational amplifier in the scale change unit by changing the reference voltage output by the reference voltage output unit based on the output signal of the operational amplifier.

9. The input device according to claim 8, wherein the control unit controls the reference voltage such that the converted value obtained by converting the output signal of the operational amplifier into a predetermined bit gradation value falls between a first gradation value and a second gradation value that is greater than the first gradation value.

10. An input device according to any one of claims 1 to 6, comprising: an inverting amplifier circuit including an operational amplifier having an inverting input terminal to which the combined output signal is input; and a scale changing unit having a reference voltage output unit that outputs a reference voltage to the non-inverting input terminal of the operational amplifier in a changeable manner, further comprising a scale changing unit that changes the scale of the output signal of the operational amplifier, wherein the output combining unit is a wired-or connection unit having an output terminal that connects the output terminals of the plurality of displacement detection units in a wired-or format and outputs the combined output signal, wherein the plurality of displacement detection units are a plurality of reflective light sensors provided on the substrate, and the control unit controls the reference voltage input to the non-inverting input terminal of the operational amplifier so that the output of the operational amplifier is binarized.

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