Pressure detection device, electronic apparatus, and information processing method

Abstract

[Problem] To provide a technique capable of easily simplifying and miniaturizing a structure in a pressure detection device capable of detecting an inclination component of a force. [Solution] A pressure detection device according to the present technique comprises a pressure distribution sensor, a first layer, a second layer, and a control unit. The pressure distribution sensor can detect, as a pressure distribution waveform, a force that may include an inclination component. The first layer is disposed on the side to which a force is applied, this side being opposite to the pressure distribution sensor. The second layer is interposed between the pressure distribution sensor and the first layer and has a hardness different from that of the first layer. The control unit calculates the inclination component on the basis of the pressure distribution waveform.

Description

Pressure detection device, electronic device, and information processing method

[0001] The present technology relates to a technology for a pressure detection device that detects pressure.

[0002] 2. Description of the Related Art In recent years, pressure detection devices that detect the pressure of an input force have become widely known.

[0003] Patent Document 1 below discloses a force detection device used as an input device for electronic devices, for example. This force detection device includes an inner box-like structure formed in a rectangular box shape and an outer box-like structure formed in a rectangular box shape and provided to cover the periphery of the inner structure. The force detection device also includes a disk-shaped force receiving body attached to a position above the outer box-like structure via a columnar connecting part.

[0004] A plurality of fixed electrodes are provided on the outer periphery of the inner box-shaped structure, and a plurality of variable electrodes are provided on the inner periphery of the outer box-shaped structure so as to face the plurality of fixed electrodes. When a force is applied to a force receiving body of the outer box-shaped structure, the capacitances of the plurality of fixed electrodes and the plurality of variable electrodes change. The technology described in Patent Document 1 utilizes this relationship to detect force components Fx, Fy, and Fz in three axial directions of a force input via the force receiving body, as well as moment components Mx, My, and Mz about three axes.

[0005] JP 2004-301731 A

[0006] The technology of Patent Document 1 can detect various components of force including moment components, but has problems such as a complex structure and difficulty in miniaturization.

[0007] In view of the above circumstances, an object of the present technology is to provide a technology that can easily simplify the structure and reduce the size of a pressure detection device that can detect a force gradient component.

[0008] A pressure detection device according to the present technology includes a pressure distribution sensor, a first layer, a second layer, and a control unit. The pressure distribution sensor is capable of detecting a force that may include a gradient component as a pressure distribution waveform. The first layer is disposed on the side opposite to the pressure distribution sensor where the force is applied. The second layer is interposed between the pressure distribution sensor and the first layer and has a hardness different from that of the first layer. The control unit calculates the gradient component based on the pressure distribution waveform.

[0009] In this pressure detection device, the gradient component of the force can be detected based on the pressure distribution waveform detected by the pressure distribution sensor, which facilitates simplification and miniaturization of the sensor structure (pressure distribution sensor, first layer, second layer). Furthermore, by varying the hardness of the first layer and the second layer, the gradient component is more likely to be reflected in the pressure distribution waveform, making it possible to detect the gradient with high accuracy.

[0010] In the above pressure detection device, the pressure distribution sensor may be capable of detecting a force that may include a shear component as a pressure distribution waveform, and the control unit may calculate the shear component based on the pressure distribution waveform.

[0011] This allows both the gradient and shear components of the force to be determined from the pressure distribution waveform.

[0012] In the above pressure detection device, the control unit may separate the pressure distribution waveform into a first region where the slope component is relatively dominant and a second region where the shear component is relatively dominant, calculate the slope component based on the first region, and calculate the shear component based on the second region.

[0013] This makes it possible to appropriately determine the gradient component and shear component of the force from the pressure distribution waveform.

[0014] In the pressure distribution detection device, the control unit may set a region of the pressure distribution waveform where the pressure value is equal to or greater than a predetermined threshold as a first region, and set a region where the pressure value is less than the predetermined threshold as a second region.

[0015] This allows the first region and the second region to be appropriately separated.

[0016] In the pressure detection device, the control unit may variably control the predetermined threshold value.

[0017] This allows the threshold to be set at an appropriate position for each pressure distribution waveform.

[0018] In the pressure detection device, the control unit acquires image data including the pressure distribution waveform, and performs image processing on the image data to set the predetermined threshold value.

[0019] This allows the threshold to be set at an appropriate position depending on the outer shape of the pressure distribution waveform, etc.

[0020] In the pressure detection device, the image processing may be edge extraction processing.

[0021] This allows the threshold to be set with high precision.

[0022] In the pressure detection device, the control unit may calculate an inclination angle of the first region with respect to a direction parallel to the pressure distribution sensor, and calculate the inclination component based on the inclination angle.

[0023] This makes it possible to accurately determine the force gradient component from the pressure distribution waveform.

[0024] In the above pressure detection device, the control unit may calculate a movement distance of the second region in a direction parallel to the pressure distribution sensor, and calculate the shear component based on the movement distance.

[0025] This allows the shear component of the force to be determined with high accuracy from the pressure distribution waveform.

[0026] In the above pressure detection device, the second layer may be softer than the first layer.

[0027] This makes it possible to accurately determine the inclination of the object applying the force from the gradient component of the force.

[0028] In the above pressure detection device, the first layer may be softer than the second layer.

[0029] This makes it possible to accurately determine the shape of the object to which the force is applied from the gradient component of the force.

[0030] In the above pressure detection device, the area of ​​the first layer in a direction along the first layer may be larger than the area of ​​the second layer in a direction along the second layer.

[0031] This makes it easier for the force gradient component to be reflected in the pressure distribution waveform, and the force gradient component can be determined appropriately.

[0032] In the pressure detection device, the area of ​​the first layer may be 125% or more of the area of ​​the second layer.

[0033] This makes it easier for the force gradient component to be reflected in the pressure distribution waveform.

[0034] In the pressure detection device, the area of ​​the first layer in a direction along the first layer may be smaller than the area of ​​the second layer in a direction along the second layer.

[0035] This makes it easier for the shear component of the force to be reflected in the pressure distribution waveform, making it possible to appropriately determine the shear component of the force.

[0036] In the above pressure detection device, the area of ​​the first layer may be 80% or less of the area of ​​the second layer.

[0037] This makes it easier for the shear component of the force to be reflected in the pressure distribution waveform.

[0038] In the above pressure detection device, the second layer may have an inverted frustum shape.

[0039] This makes it easier for the force gradient component to be reflected in the pressure distribution waveform, and the force gradient component can be determined appropriately.

[0040] In the above pressure detection device, the second layer may have a frustum shape.

[0041] This makes it easier for the shear component of the force to be reflected in the pressure distribution waveform, allowing the shear component of the force to be determined appropriately.

[0042] A pressure detection device according to another aspect of the present technology includes a control unit, wherein the control unit separates a pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a slope component and a shear component as a pressure distribution waveform into a first region where the slope component is relatively dominant and a second region where the shear component is relatively dominant, and calculates the slope component based on the first region and the shear component based on the second region.

[0043] In this pressure detection device, both the gradient component and shear component of the force can be determined from the pressure distribution waveform. Also, since the gradient component of the force is determined based on the first region of the pressure distribution waveform and the shear component of the force is determined based on the second region, the gradient component and shear component of the force can be determined with high accuracy. Furthermore, since this pressure distribution device can determine the gradient component and shear component of the force from the pressure distribution waveform, it is easy to simplify and miniaturize the sensor structure.

[0044] An electronic device according to the present technology includes a pressure detection device. The pressure detection device includes a pressure distribution sensor, a first layer, a second layer, and a control unit. The pressure distribution sensor is capable of detecting a force that may include a gradient component as a pressure distribution waveform. The first layer is disposed on the side opposite to the pressure distribution sensor where the force is applied. The second layer is interposed between the pressure distribution sensor and the first layer and has a hardness different from that of the first layer.

[0045] An information processing method according to the present technology separates a pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a slope component and a shear component as a pressure distribution waveform into a first region where the slope component is relatively dominant and a second region where the shear component is relatively dominant, calculates the slope component based on the first region, and calculates the shear component based on the second region.

[0046] 1 is a block diagram showing a pressure detection device according to a first embodiment of the present technology; FIG. 2 is a side view showing a configuration of a sensor unit included in the pressure detection device; FIG. 3 is a diagram for explaining a concept related to a processing algorithm of a control unit; FIG. 4 is a diagram for explaining a concept related to a processing algorithm of a control unit; FIG. 5 is a diagram showing a relationship between movements of a first layer and a second layer when a gradient component of a force is applied and when a shear component of a force is applied, and a pressure distribution waveform at that time; FIG. 6 is a diagram showing a relationship between various user operations and a pressure distribution waveform due to the user operations; FIG. 7 is a flowchart showing processing of a control unit; FIG. 8 is a diagram showing sensor data including a mountain-shaped pressure distribution waveform; FIG. 9 is a diagram showing a state when an approximation plane of a first region gradually tilts from a state nearly parallel to a horizontal plane; FIG. 10 is a schematic diagram showing a state when the approximation plane of the first region tilts; FIG. 11 is a schematic diagram showing a state when the center of gravity position of a second region moves in the planar direction; FIG. 12 is a schematic diagram showing a configuration of a sensor unit according to a second embodiment; FIG. 13 is a schematic diagram showing a configuration of a sensor unit according to a second embodiment; FIG. 10 is a schematic diagram showing the configuration of a sensor unit according to a third embodiment. FIG. 11 is a schematic diagram showing the configuration of a sensor unit according to a third embodiment. FIG. 12 is a schematic diagram showing the configuration of a sensor unit according to a third embodiment. FIG. 13 is a schematic diagram showing the configuration of a sensor unit according to a fourth embodiment.

[0047] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0048] First Embodiment Overall Configuration and Configuration of Each Part Fig. 1 is a block diagram showing a pressure detection device 10 according to a first embodiment of the present technology. Fig. 2 is a side view showing the configuration of a sensor unit 12 included in the pressure detection device 10.

[0049] The pressure detection device 10 is mounted on various electronic devices such as smartphones, cameras, game controllers, etc., and is used as an input device therefor. For ease of understanding, the present specification will describe, as an example, a case in which the pressure detection device 10 is used as an input device for an electronic device. Also, as an example, the case in which the object that applies pressure to the sensor unit 12 is an object related to user operation, such as a finger or a touch pen, will be described.

[0050] On the other hand, the pressure detection device 10 according to the present technology is not limited to an input device and can be used for any purpose as long as it is intended to detect pressure. Furthermore, the object that applies pressure to the sensor unit 12 is not limited to an object related to a user's operation, and may be a mechanical element unrelated to a user's operation, or any other object.

[0051] 1, the pressure detection device 10 includes a control unit 11, a sensor unit 12, a memory unit 13, and an output unit 14. As shown in Fig. 2, the sensor unit 12 includes a pressure distribution sensor 3, a second layer 2 laminated on the pressure distribution sensor 3, and a first layer 1 laminated on the second layer 2 so as to cover the entire second layer 2.

[0052] The control unit 11 executes various calculations based on various programs stored in the storage unit 13, and performs overall control of each unit of the pressure detection device 10. Typically, the control unit 11 calculates various components of the force applied to the sensor unit 12 based on the pressure distribution waveform W acquired by the sensor unit 12 (pressure distribution sensor 3).

[0053] In this embodiment, the control unit 11 calculates a pressure component, a tilt component, and a shear component as various components of the force. The pressure component is a component in the Z-axis direction in a three-axis Cartesian coordinate system, and indicates the magnitude of a force applied downward to the sensor unit 12. The tilt component is a component represented by, for example, an angle θ from the Z-axis direction or an angle φ from the X-axis direction in a spherical coordinate system (see FIGS. 10 and 11 below for θ and φ), and indicates the direction (φ) and degree of tilt (θ) at which the force is applied.

[0054] The shear component is a component in a direction parallel to the XY plane in a three-axis Cartesian coordinate system, and refers to the magnitude of the force applied in a planar direction (XY plane) when an object (e.g., a finger) applying force to the sensor unit 12 moves in a planar direction (XY plane) without sliding across the surface of the sensor unit 12 (even if it slides slightly). In other words, when an object (e.g., a finger) applying force to the sensor unit 12 moves in a planar direction (XY plane) without sliding across the surface of the sensor unit 12 (even if it slides slightly), the layered structure on the sensor unit 12 undergoes shear deformation (see FIGS. 4 and 6). The magnitude of this shear deformation correlates with the magnitude of the force applied in the planar direction, and this relationship is used to calculate the magnitude of the force in the planar direction.

[0055] The control unit 11 is realized by hardware or a combination of hardware and software. The hardware is configured as part or all of the control unit 11, and examples of this hardware include a central processing unit (CPU), a graphics processing unit (GPU), a vision processing unit (VPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a combination of two or more of these.

[0056] The storage unit 13 includes a non-volatile memory that stores various programs and various data required for processing by the control unit 11, and a volatile memory that is used as a work area for the control unit 11.

[0057] The various programs described above may be read from a portable recording medium such as an optical disk or semiconductor memory, or may be downloaded from a server device on a network.

[0058] The output unit 14 outputs various pieces of information obtained by the control unit 11 to an external device (for example, a main control unit of an electronic device) in response to a command from the control unit 11 .

[0059] When the pressure detection device 10 is mounted on an electronic device, the main control unit of the electronic device may function as the control unit 11 of the pressure detection device 10. In this case, the main memory unit of the electronic device may function as the memory unit 13 of the pressure detection device 10.

[0060] The sensor unit 12 includes a pressure distribution sensor 3, a first layer 1 disposed on the side opposite the pressure distribution sensor 3 where force is applied, and a second layer 2 interposed between the pressure distribution sensor 3 and the first layer 1. The sensor unit 12 has a laminated structure in which the pressure distribution sensor 3, the second layer 2, and the first layer 1 are laminated in this order from the bottom.

[0061] The pressure distribution sensor 3 detects the force applied via the first layer 1 and the second layer 2 as a pressure distribution waveform W and outputs it to the control unit 11. The pressure distribution sensor 3 may be configured to be able to detect the pressure distribution in one dimension, or may be configured to be able to detect the pressure distribution in two dimensions.

[0062] The pressure distribution sensor 3 is configured with various types of pressure sensors, such as capacitive, resistive, or optical sensors. The pressure distribution sensor 3 may have any configuration as long as it can detect pressure distribution. The pressure distribution sensor 3 has, for example, an array structure, and in this case, the array pitch is, for example, about 1 to 3 mm. In this case, the number of arrays is, for example, 3 x 3 or more (in the XY plane direction).

[0063] The first layer 1 and the second layer 2 have different hardnesses and are made of different materials. In this embodiment, the second layer 2 is made softer than the first layer 1. On the other hand, the first layer 1 can also be made softer than the second layer 2. An embodiment in which the first layer 1 is made softer than the second layer 2 will be described later in the fourth embodiment.

[0064] In this embodiment, the first layer 1 is a layer (non-deformable layer, non-stretchable layer) that is relatively less susceptible to deformation and stretching than the second layer 2. The first layer 1 is made of various materials, for example, resin materials such as ABS (Acrylonitrile Butadiene Styrene) resin, metal materials, hard rubber, etc.

[0065] The top surface of the first layer 1 is the side that comes into contact with an object (e.g., a finger) that applies force to the sensor unit 12. If the object (e.g., a finger) that applies force to the sensor unit 12 slips on the top surface of the first layer 1, the shear component of the force cannot be properly detected. For this reason, in this embodiment, the top surface of the first layer 1 has a high static friction coefficient that prevents the object (e.g., a user's finger) that applies force to the sensor unit 12 from slipping. This static friction coefficient is, for example, 0.5 or greater.

[0066] In order to impart a high coefficient of static friction to the upper surface of the first layer 1, a material having a high coefficient of static friction may be selected as the material for the first layer 1. Alternatively, a plurality of fine concave and convex shapes may be formed on the upper surface of the first layer 1 to impart a high coefficient of static friction. Alternatively, a film having a high coefficient of static friction may be laminated on the upper surface of the first layer 1.

[0067] On the other hand, in this embodiment, the second layer 2 is relatively more easily deformed and stretched (deformable layer, stretchable layer) than the first layer 1. In particular, in this embodiment, the second layer 2 is configured to appropriately shear when an object (e.g., a finger) applying force to the sensor unit 12 moves in a planar direction (XY plane direction) without sliding on the top surface of the first layer 1 (or the film layer thereon) (some sliding is acceptable).

[0068] For this reason, the second layer 2 is made of a shear-deformable material, such as elastomer, gel, soft rubber, and the like.

[0069] In this embodiment, the three-dimensional shapes of the first layer 1 and the second layer 2 are the same, and the areas in the direction along the layers (in this example, the XY plane direction) are also the same. However, the three-dimensional shapes and areas of the first layer 1 and the second layer 2 can also be different (see FIGS. 14 and 15 described below).

[0070] The shapes of the first layer 1 and the second layer 2 in a plan view may be any shape, such as a circle, a polygon, a star, etc. The area of ​​the first layer 1 and the second layer 2 (in the direction along the layer) is, for example, 100 mm ２ 1250mm or more ２ The total thickness of the first layer 1 and the second layer 2 is, for example, 0.3 mm or more and 10 mm or less.

[0071] In this embodiment, the laminated structure on the pressure distribution sensor 3 is a two-layer laminated structure including a first layer 1 and a second layer 2, but this laminated structure may also be three or more layers.

[0072] <Concept of the processing algorithm of the control unit 11> Next, we will explain the concept of the processing algorithm of the control unit 11. Figures 3 to 5 are diagrams for explaining the concept of the processing algorithm of the control unit 11. In Figures 3 to 5, the sensor unit 12 is configured by laminating a single deformation layer 4 on a pressure distribution sensor 3.

[0073] The upper left of Figure 3 shows the state when a downward force is applied to the deformation layer 4 by the striking element 5, causing the deformation layer 4 to be pressed, and the dashed line in the center of Figure 3 shows the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time.

[0074] The lower left of Figure 3 shows the state when the deformation layer 4 is pressed, the keystroke 5 tilts, and the deformation layer 4 is deformed accordingly. The center of Figure 3 shows the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time, shown by a solid line.

[0075] As can be seen from FIG. 3, when the tapping element 5 is tilted, the shape of the upper region (first region R) of the mountain-shaped pressure distribution waveform W changes significantly, while the shape of the lower region (second region R') of the pressure distribution waveform W does not change much.

[0076] The upper left of Figure 4 shows the state when a downward force is applied to the deformation layer 4 by the keystroke 5, causing the deformation layer 4 to be pressed, and the dashed line in the center of Figure 4 shows the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time.

[0077] The lower left of Figure 4 shows the state when, after the deformation layer 4 is pressed, the striking element 5 moves in a planar direction (XY plane), causing the deformation layer 4 to undergo shear deformation in response. The center of Figure 3 shows, in solid lines, the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time.

[0078] From FIG. 4, it can be seen that when the tapping element 5 moves (shears) in a planar direction, the shape of the upper region of the mountain-shaped pressure distribution waveform W remains largely unchanged (moves in the planar direction), while the lower region of the pressure distribution waveform W moves in the planar direction (XY plane) (without significantly changing shape).

[0079] Here, there are cases where the tapping element 5 moves in a planar direction (XY plane) while the inclination of the tapping element 5 changes. This state is shown in FIG.

[0080] The upper left of Figure 5 shows the state when a downward force is applied to the tapping element 5 while it is tilted counterclockwise, thereby pressing the deformation layer 4. In the center of Figure 5, the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time is shown by a dashed line.

[0081] The lower left of Figure 5 shows what happens when the tapping element 5 subsequently tilts clockwise while simultaneously moving in a planar direction (XY plane), and the center of Figure 5 shows the pressure distribution waveform W detected by the pressure distribution sensor 3 at this time by a solid line.

[0082] 5, it can be seen that when the tapping element 5 is tilted, the shape of the upper region (first region R) of the mountain-shaped pressure distribution waveform W changes significantly, while the shape of the lower region (second region R') of the pressure distribution waveform W does not change much. Also, it can be seen from Fig. 5 that when the tapping element 5 moves (shears) in a planar direction, the lower region of the mountain-shaped pressure distribution waveform W moves in the planar direction (XY plane) (without changing its shape much).

[0083] As is clear from the explanations of Figures 3 to 5, it can be seen that the upper region (first region R) of the mountain-shaped pressure distribution waveform W is the region that is dominant for the gradient component of the force applied by the tapping element 5, and the lower region (second region R') is the region that is dominant for the shear component of the force applied by the tapping element 5.

[0084] Therefore, in this embodiment, the control unit 11 executes the following process. First, the control unit 11 separates the mountain-shaped pressure distribution waveform W into a first region R where the pressure value is equal to or greater than the separation threshold, and a second region R' where the pressure value is less than the separation threshold. Next, the control unit 11 calculates the gradient component of the force based on the first region R, and calculates the shear component of the force based on the second region R'. This makes it possible to calculate both the gradient component and the shear component of the force from a single pressure distribution waveform W.

[0085] In this way, if the gradient and shear components of the force can be determined from a single pressure distribution waveform W, there is no need to complicate the structure of the entire sensor unit 12 in order to determine the gradient and shear components, and it also becomes easier to miniaturize the structure of the entire sensor unit 12.

[0086] The above is the concept regarding the processing algorithm of the control unit 11.

[0087] <Layer structure including first layer 1 and second layer 2> As described above, one of the objectives of this embodiment is to appropriately detect the force gradient component and shear component (particularly the gradient component) from a single pressure distribution waveform W. In this case, if the layer structure on the pressure distribution sensor 3 is a single-layer structure, there is a possibility that the force gradient component and shear component cannot be appropriately detected.

[0088] Therefore, in this embodiment, the layer structure on the pressure distribution sensor 3 is a laminated structure including a first layer 1 and a second layer 2 (or more), and the first layer 1 and the second layer 2 have different hardnesses. In particular, in this embodiment, the second layer 2 is configured to be softer than the first layer 1.

[0089] FIG. 6 shows the relationship between the movement of the first layer 1 and the second layer 2 when a gradient component of force is applied and when a shear component of force is applied, and the pressure distribution waveform W at that time.

[0090] As shown on the left side of Figure 6, suppose that after a downward force is applied by the tapping element 5 (pressure distribution waveform W in dashed lines), the tapping element 5 tilts (pressure distribution waveform W in solid lines). In this case, the relatively hard first layer 1 tilts overall without changing its shape much, while the relatively soft second layer 2 deforms.

[0091] As shown on the right side of Figure 6, suppose that a downward force is applied by the tapping element 5 (pressure distribution waveform W shown by the dashed line) and then the tapping element 5 moves in a planar direction (XY plane) (pressure distribution waveform W shown by the solid line). In this case, the relatively hard first layer 1 moves in the planar direction without changing its shape much, while the relatively soft second layer 2 undergoes shear deformation.

[0092] In this way, by configuring the layer structure on the pressure distribution sensor 3 as a laminated structure of two or more layers with different hardness, the gradient component of the force is more easily reflected in the first region R of the pressure distribution waveform W, and the shear component of the force is more easily reflected in the second region R' of the pressure distribution. This makes it easier to separate the gradient component and shear component of the force.

[0093] <User Operations> Next, various user operations will be described. Fig. 7 is a diagram showing the relationship between various user operations and the pressure distribution waveform W resulting from the user operations. As shown in Fig. 7, in this embodiment, three types of user operations are provided: a pressing operation, a shearing operation, and a tilting operation.

[0094] 7, a pressing operation is an operation in which a finger (an example of an object that applies force) is pressed downward on the sensor unit 12 with a force equal to or greater than a certain force (a force that serves as a criterion for determining whether a pressing operation is performed; this force is different from the separation threshold) without tilting the finger. As shown on the left side of Fig. 7, when the user presses the sensor unit 12 without tilting the finger and then further presses the sensor unit 12 with the finger, the height of the pressure distribution waveform W changes to become higher.

[0095] 7, a shearing operation is an operation in which a finger (an example of an object applying force) is moved in a planar direction (XY plane) while pressing the sensor unit 12 downward with a force equal to or greater than a certain force (input determination threshold: see ST102 described later) without tilting the finger. As shown in the second from the left in Fig. 7, when a user moves the finger in a planar direction while pressing the sensor unit 12 without tilting the finger, the pressure distribution waveform W moves in a corresponding direction in the planar direction without changing its shape much.

[0096] 7, the tilt operation is an operation of tilting a finger (an example of an object that applies force) and pressing the sensor unit 12 diagonally downward with a force equal to or greater than a certain force (input determination threshold: see ST102 described later). As shown in the rightmost and second from the right in Fig. 7, when a user presses the sensor unit 12 diagonally downward while tilting their finger, the shape of the upper side (first region R) of the pressure distribution waveform W changes in accordance with the tilt direction.

[0097] In this embodiment, various functions to be executed are assigned to the pressing operation, the shearing operation, and the tilting operation. For example, if the electronic device in which the pressure detection device 10 is installed is a camera, the functions assigned to each operation are, for example, shutter, zoom in, zoom out, etc.

[0098] For a pressing operation, a different function may be assigned depending on which position in a planar direction (XY plane) is pressed with a finger. For a shearing operation, a different function may be assigned depending on which direction (and how much) the finger moves in a planar direction. For a tilting operation, a different function may be assigned depending on which direction (spherical coordinate φ) the finger is tilted in (and how much: spherical coordinate θ).

[0099] In this embodiment, despite the simple structure and small size of the sensor unit 12, various functions can be assigned to three types of operations: pressing operation, shearing operation, and tilting operation (especially shearing operation and tilting operation), so a large number of functions can be assigned.

[0100] Furthermore, in this embodiment, the pressing component, shearing component, and tilting component of the force can be accurately determined from the pressure distribution waveform W (see the description of the processing by the control unit 11 below), so that the pressing operation, shearing operation, and tilting operation by the user can be accurately determined. Therefore, individual differences in the pressing operation, shearing operation, and tilting operation of each user can be appropriately absorbed, and each operation can also be used for personal authentication, etc.

[0101] <Processing of Control Unit 11> Next, a description will be given of the processing of the control unit 11. Figures 8 and 9 are flowcharts showing the processing of the control unit 11. Figure 10 is a diagram showing sensor data including a mountain-shaped pressure distribution waveform W.

[0102] First, the control unit 11 acquires sensor data (data having pixels of W×H pixels) including a pressure distribution waveform W from the pressure distribution sensor 3 (ST101) (see FIG. 10).

[0103] Next, the control unit 11 determines whether the sensor unit 12 has been pressed (ST102) based on the pressure distribution waveform W. The determination of whether the sensor unit 12 has been pressed is made based on, for example, whether the maximum pressure value among the pressure values ​​indicated by the pressure distribution waveform W is equal to or greater than the input determination threshold value.

[0104] In this case, when the maximum pressure value is equal to or greater than the input determination threshold, it is determined that the sensor unit 12 is pressed, whereas when the maximum pressure value is less than the input determination threshold, it is determined that the sensor unit 12 is not pressed. The input determination threshold is a value that serves as a criterion for determining input to the sensor unit 12, and is set to an appropriate value so that intended inputs can be appropriately determined and unintended inputs can be appropriately rejected.

[0105] If the sensor unit 12 is not pressed (NO in ST102), the control unit 11 determines whether or not the sensor unit 12 was determined to be pressed in the previous determination in ST102 (ST103).

[0106] If it was determined in the previous determination that the sensor unit 12 was pressed (YES in ST103), the control unit 11 determines that the input to the sensor unit 12 has been released (ST104) and returns to ST101. On the other hand, if it was determined in the previous determination that the sensor unit 12 was not pressed (NO in ST103), the control unit 11 returns to ST101 without going through ST104.

[0107] If it is determined in ST102 that the sensor unit 12 has been pressed (YES in ST102), the control unit 11 determines whether the sensor data has a multi-peak distribution including multiple mountain-shaped pressure distribution waveforms W (ST105).

[0108] In the case of a multi-modal distribution (YES in ST105), the control unit 11 selects one pressure distribution waveform W from the multiple pressure distribution waveforms W (ST106). In this case, the control unit 11 typically preferentially selects, from the multiple pressure distribution waveforms W, the waveform that exhibits the highest maximum pressure value or the waveform with the largest size.

[0109] In the determination of ST106, for example, if the number of pixels in the sensor data is large, object detection processing such as SSD (Single Shot Multi-box Detector), YOLO (You Only Look Once), etc. is executed. On the other hand, if the number of pixels in the sensor data is small, multiple local maximum value search, etc. is executed.

[0110] After one pressure distribution waveform W is determined, the control unit 11 executes noise removal processing by a method using a Gaussian filter, a bilateral filter, a constant threshold value, or the like (ST107).

[0111] Next, the control unit 11 separates the pressure distribution waveform W into a first region R where the pressure value is equal to or greater than the separation threshold, and a second region R' where the pressure value is less than the separation threshold (ST108). Typically, the first region R is a region on the upper side of the mountain-shaped pressure distribution waveform W that appropriately includes a portion where the mountain shape is broken and deformed, and the second region R' is a region on the lower side of the pressure distribution waveform W that excludes the deformed upper region (first region R).

[0112] As a method for setting a separation threshold for separating the first region R and the second region R', the following four methods 1. to 4. can be given, for example.

[0113] 1. Constant: A certain pressure value is preset as a constant, and this value is used as the separation threshold. 2. Ratio: For example, a pressure value that is a certain ratio (e.g., 50%) of the maximum pressure of the pressure distribution waveform W is used as the separation threshold (i.e., variable). 3. Otsu's binarization method: Image processing using Otsu's binarization method is performed on image data including the pressure distribution waveform W, and the separation threshold is determined (i.e., variable). 4. Edge extraction processing: Edge extraction processing (image processing) using, for example, a Laplacian filter (second-order differential) is performed on image data including the pressure distribution waveform W, and the separation threshold is determined based on the extraction results (i.e., variable). The separation threshold may be determined by combining two or more of the methods 1 to 4 above. The separation threshold may also be determined by machine learning.

[0114] After separating the pressure distribution waveform W into the first region R and the second region R' using the separation threshold, the control unit 11 then calculates the current tilt angle based on the first region R (ST109). When calculating the tilt angle, for example, the control unit 11 calculates an approximate plane P for the first region R, and calculates the angle at which this approximate plane P is tilted with respect to the planar direction (XY plane), thereby calculating the tilt angle.

[0115] Fig. 11 is a diagram showing a state in which the approximate plane P of the first region R gradually tilts from a state in which it is nearly parallel to the horizontal plane. Fig. 12 is a schematic diagram showing a state in which the approximate plane P of the first region R tilts.

[0116] After calculating the current tilt angle, control unit 11 next determines whether this is the first time in the pressure determination in ST102 (ST110). If this is the first time (YES in ST110), control unit 11 stores the current tilt angle in memory unit 13 as the first tilt angle (ST111), skips ST112 and ST113, and proceeds to ST114.

[0117] If this is not the first time but the second time or later (NO in ST110), the control unit 11 calculates the difference between the current tilt angle and the first tilt angle (current tilt angle - first tilt angle) (ST112).

[0118] Next, the control unit 11 converts the difference amount into a gradient component of the force, for example, by affine transformation (ST113).

[0119] In the above description, the tilt angle is calculated from the change in the approximate plane P of the first region R. However, the tilt angle may be calculated from the change in the center of gravity position of the first region R.

[0120] Referring to FIG. 9, next, control unit 11 calculates the current center of gravity position of second region R' (ST114).

[0121] FIG. 13 is a schematic diagram showing a state when the center of gravity position of the second region R′ moves in a planar direction (XY plane).

[0122] After calculating the current center of gravity position, the control unit 11 next determines whether this is the first time in the pressing determination in ST102 (ST115). If this is the first time (YES in ST115), the control unit 11 stores the current center of gravity position in the storage unit 13 as the first center of gravity position (ST116), skips ST117 and ST118, and returns to ST101.

[0123] If this is not the first time but the second time or later (NO in ST115), the control unit 11 calculates the difference between the current center of gravity position and the initial center of gravity position (current center of gravity position - initial center of gravity position: movement distance) (ST117).

[0124] Next, the control unit 11 converts the difference amount into a shear component of the force, for example, by affine transformation (ST118), and returns to ST101. Thereafter, the processes from ST101 onwards are repeatedly executed at a predetermined cycle (for example, on the order of tens to hundreds of ms).

[0125] Here, the control unit 11 determines that a tilt operation has been input when the pressure component of the force is equal to or greater than the input determination threshold (see ST102) and the tilt angle (θ) of the tilt component of the force is equal to or greater than a predetermined angle. Also, the control unit 11 determines that a shear operation has been input when the pressure component of the force is equal to or greater than the input determination threshold (see ST102) and the shear component of the force is equal to or greater than a predetermined value.

[0126] Furthermore, when the tilt component is less than a predetermined angle and the shear component is less than a predetermined value, the control unit 11 determines that a pressing operation has been input when the pressing component of the force is equal to or greater than a predetermined threshold (a threshold set to a value higher than the input determination threshold).When each operation is input, the corresponding function is executed by the electronic device.

[0127] <Functions, etc.> As described above, in the pressure detection device 10 according to this embodiment, the slope component and shear component (and pressure component) are calculated based on the pressure distribution waveform W detected by the pressure distribution sensor 3, which is capable of detecting a force that may include a slope component and a shear component (and pressure component) as a pressure distribution waveform W.

[0128] In this way, in this embodiment, the force gradient component and shear component (and pressure component) can be determined based on the pressure distribution waveform W, making it easy to simplify and miniaturize the sensor structure. However, as mentioned above, if the force gradient component is determined using conventional methods, the sensor structure tends to become complicated and large. Therefore, determining the force gradient component from the pressure distribution waveform W, as in this embodiment, is particularly effective.

[0129] In this embodiment, the gradient component is calculated based on a first region R of the pressure distribution waveform W where the gradient component of the force is relatively dominant. This allows the gradient component of the force to be determined with high accuracy. Furthermore, the shear component is calculated based on a second region R' of the pressure distribution waveform W where the shear component of the force is relatively dominant. This allows the shear component of the force to be determined with high accuracy.

[0130] In this embodiment, the region of the pressure distribution waveform W where the pressure value is equal to or greater than the separation threshold is set as the first region R, and the region where the pressure value is less than the separation threshold is set as the second region R'. This allows the pressure distribution waveform W to be appropriately separated into the first region R where the gradient component of the force is dominant and the second region R' where the shear component of the force is dominant.

[0131] Furthermore, in this embodiment, the separation threshold can be variably controlled. By making the separation threshold variable in this way, the separation threshold can be appropriately set depending on the shape of the pressure distribution waveform W. In this case, by setting the separation threshold while recognizing the outer shape of the pressure distribution waveform W by image processing the sensor data including the pressure distribution waveform W, the separation threshold can be set at a more appropriate position.

[0132] In this embodiment, the tilt angle (for example, the tilt angle of the approximation plane P) of the first region R relative to the planar direction (XY plane) is determined, and the gradient component of the force is calculated based on this tilt angle. This allows the gradient component of the force to be determined with high accuracy.

[0133] In this embodiment, the movement distance in the second region R' in a planar direction (XY plane) (for example, the movement distance of the center of gravity of the second region R') is calculated, and the shear component is calculated based on this movement distance. This makes it possible to accurately calculate the shear component of the force.

[0134] In this embodiment, the sensor unit 12 has a two-layer structure (or three or more layers) on the pressure distribution sensor 3, which includes a first layer 1 and a second layer 2 (such a simple layer structure is possible because the slope component and shear component can be determined from the pressure distribution waveform W). In this embodiment, the first layer 1 and the second layer 2 have different hardnesses, with the second layer 2 being softer than the first layer 1.

[0135] This makes it easier for the gradient component of the force to be reflected in the first region R of the pressure distribution waveform W, and for the shear component of the force to be reflected in the second region R' of the pressure distribution waveform W. This makes it easier to separate the gradient component of the force from the shear component in the pressure distribution waveform W.

[0136] Second Embodiment (Layer structure that facilitates detection of force gradient component) Next, a second embodiment of the present technology will be described. In the descriptions of the second embodiment and subsequent embodiments, parts having the same configurations and functions as those in the first embodiment described above will be denoted by the same reference numerals, and descriptions thereof will be omitted or simplified.

[0137] Here, it is possible to set which of the shear component of the force and the gradient component of the force is easier to detect by changing the shapes of the first layer 1 and the second layer 2. In this second embodiment, a configuration that makes it easier to detect the gradient component of the force out of the shear component and gradient component of the force will be described, and in a third embodiment described later, a configuration that makes it easier to detect the shear component of the force will be described.

[0138] 14A to 14E are schematic diagrams showing the configuration of the sensor unit 12 according to the second embodiment.

[0139] 14A to 14E, the materials used for the first layers 1a to 1e and the second layers 2a to 2e are the same as those in the first embodiment. Furthermore, a film having a static friction constant high enough to prevent an object applying pressure (e.g., a finger) from slipping may be laminated on the upper surfaces of the first layers 1a to 1e. Furthermore, the upper surfaces of the first layers 1a to 1e may be provided with a plurality of irregularities to impart a high static friction coefficient. This also applies to the third embodiment described below.

[0140] 14A to 14E, the first layers 1a to 1e entirely cover the upper surfaces of the second layers 2a to 2e, and the areas of the first layers 1a to 1e in the direction parallel to the layers 1a to 1e are set to be larger than the areas of the second layers 2a to 2e in the direction parallel to the layers 2a to 2e.

[0141] In the first layers 1a to 1e, the area along the first layers 1a to 1e refers to the area of ​​the lower surface of the first layers 1a to 1e facing the second layers 2a to 2e. Typically, the area along the first layers 1a to 1e refers to the maximum area along the planar direction (XY plane). For example, in FIGS. 14B, 14C, and 14D, the first layers 1b, 1c, and 1d are rectangular parallelepipeds, and the area in the planar direction is constant and does not change in the height direction (Z-axis direction). In this case, the area in the planar direction is the area along the first layers 1b, 1c, and 1d. On the other hand, in FIG. 14A, the first layer 1a is semispherical, and the area in the planar direction (XY plane) is not constant in the height direction (Z-axis direction). In this case, the area of ​​the lower surface of the first layer 1a, which is the largest among the areas of the first layer 1a in the planar direction, is the area of ​​the first layer 1a in the direction along the first layer 1a. Here, in Fig. 14E, the first layer 1e has a curved surface as a whole. In this way, when the first layer 1e has a curved surface, the area along the direction along the first layer 1e is not the area in the planar direction, but the area along the curved surface.

[0142] Furthermore, in the second layers 2a to 2e, the area in the direction along the second layers 2a to 2e refers to the area of ​​the upper surface of the second layers 2a to 2e facing the first layers 1a to 1e. Typically, in the second layers 2a to 2e, the area in the direction along the second layers 2a to 2e refers to the maximum area in the direction along the planar direction (XY plane). For example, in FIGS. 14C and 14D, the second layers 2c and 2d are rectangular parallelepipeds, and the area in the planar direction is constant and does not change in the height direction (Z-axis direction). In this case, the area in the planar direction is the area of ​​the second layers 2c and 2d in the direction along the second layers 2c and 2d. On the other hand, in FIGS. 14A and 14B, the second layers 2a and 2b are inverted frustum shapes, and the area in the planar direction (XY plane) is not constant in the height direction (Z-axis direction). In this case, the area of ​​the upper surface of the second layers 2a and 2b, which is the largest among the areas of the second layers 2a and 2b in the planar direction, is the area of ​​the second layers 2a and 2b in the direction along the second layers 2a and 2b. Also, in Figure 14E, the second layer 2e has a rectangular parallelepiped shape on the bottom and a semispherical shape on the top, and the area in the planar direction (XY plane) is not constant in the height direction (Z-axis direction). In this case, the area in the planar direction of the rectangular parallelepiped portion of the second layer 2e, which is the largest among the areas of the second layer 2e in the planar direction, is the area of ​​the second layer 2e in the direction along the second layer 2e.

[0143] As in the second embodiment, by making the area of ​​the first layers 1a to 1e in the direction along the first layers 1a to 1e larger than the area of ​​the second layers 2a to 2e in the direction along the second layers 2a to 2e, the force gradient component is more easily reflected in the pressure distribution waveform W, making it easier to detect the force gradient component than the force shear component. As a result, the force gradient component can be determined more accurately.

[0144] Typically, the area of ​​the first layers 1a to 1e in the direction parallel to the first layers 1a to 1e is set to 125% or more of the area of ​​the second layers 2a to 2e in the direction parallel to the second layers 2a to 2e, which makes it easier to detect the force gradient component and allows the force gradient component to be determined more accurately.

[0145] In this case, the area of ​​the first layers 1a to 1e in the direction along the layers of the first layers 1a to 1e is, for example, 100 mm ２More than 1000mm ２ The area of ​​the second layers 2a to 2e in the direction along the layers of the second layers 2a to 2e is, for example, 80 mm ２ Over 800mm ２ In this case, the total thickness of the first layer 1 and the second layer 2 is, for example, about 1 mm or more and 10 mm or less.

[0146] The first layer 1a in Fig. 14A is hemispherical and has a curved top surface. The first layer 1e in Fig. 14E is curved, and its top surface is also curved. By making the top surface of the first layer 1 curved, an object (e.g., a finger) that applies a force to the sensor unit 12 can easily come into contact with the sensor unit 12 at one point.

[0147] This makes it easier for the gradient component of the force to be reflected in the pressure distribution waveform W, making it easier to detect the gradient component of the force than the shear component of the force. As a result, the gradient component of the force can be determined more accurately.

[0148] 14A and the second layer 2b in Fig. 14B are configured in an inverted truncated cone shape (an inverted truncated circular cone, an inverted truncated polygonal pyramid, etc.). In other words, the second layers 2a and 2b have a shape in which the diameter (around the Z axis) gradually increases from the pressure distribution sensor 3 side (lower side) to the first layer 1 side (upper side).

[0149] By forming the second layer 2 in this shape, the force gradient component is more easily reflected in the pressure distribution waveform W, making it easier to detect the force gradient component than the shear component of the force. As a result, the force gradient component can be determined more accurately.

[0150] Third Embodiment (Layer structure that makes it easier to detect a shear component of a force) Next, a third embodiment of the present technology will be described. In the third embodiment, a configuration that makes it easier to detect a shear component of a force than a gradient component of a force will be described.

[0151] 15A to 15E are schematic diagrams showing the configuration of the sensor unit 12 according to the third embodiment.

[0152] 15A to 15E, the first layers 1f to 1j partially cover the upper surfaces of the second layers 2f to 2j. The areas of the first layers 1f to 1j in the direction parallel to the layers 1f to 1j are set to be smaller than the areas of the second layers 2f to 2j in the direction parallel to the layers 2f to 2j.

[0153] In the first layers 1f-1j, the area in the direction along the first layers 1f-1j refers to the area of ​​the underside of the first layers 1f-1j facing the second layers 2f-2j. Typically, the area in the direction along the first layers 1f-1j refers to the maximum area in the direction along the planar direction (XY plane). For example, in Figures 15B, 15C, and 15D, the first layers 1g, 1h, and 1i are rectangular parallelepipeds, and the area in the planar direction is constant and does not change in the height direction (Z-axis direction). In this case, the area in the planar direction is the area in the direction along the first layers 1g, 1h, and 1i. 15A and 15E, the first layers 1f and 1j are semispherical, and the areas in the planar direction (XY plane) are not constant in the height direction (Z-axis direction). In this case, the area of ​​the top surface of the first layer 1f and the area of ​​the bottom surface of the first layer 1j, which are the largest among the areas of the first layers 1f and 1j in the planar direction, are the areas of the first layers 1f and 1j in the direction along the first layers 1f and 1j.

[0154] Furthermore, in the second layers 2f-2j, the area in the direction along the second layers 2f-2j refers to the area of ​​the upper surface of the second layers 2f-2j facing the first layers 1f-1j. Typically, in the second layers 2f-2j, the area in the direction along the second layers 2f-2j refers to the maximum area in the direction along the planar direction (XY plane). For example, in Figures 15C, 15D, and 15E, the second layers 2h, 2i, and 2j are rectangular parallelepipeds, and the area in the planar direction is constant and does not change in the height direction (Z-axis direction). In this case, the area in the planar direction is the area in the direction along the second layers 2h, 2i, and 2j of the second layers 2h, 2i, and 2j. 15A and 15B, the second layers 2f and 2g have a frustum shape, and the area in the planar direction (XY plane) is not constant in the height direction (Z-axis direction). In this case, the area of ​​the lower surface of the second layers 2f and 2g, which is the largest among the areas of the second layers 2f and 2g in the planar direction, is the area of ​​the second layers 2f and 2g in the direction along the second layers 2f and 2g.

[0155] As in the third embodiment, by making the area of ​​the first layers 1f-1j in the direction along the first layers 1f-1j smaller than the area of ​​the second layers 2f-2j, the shear component of the force is more easily reflected in the pressure distribution waveform W, making it easier to detect the shear component of the force than the gradient component of the force. As a result, the shear component of the force can be determined more accurately.

[0156] Typically, the area of ​​the first layers 1f-1j in the direction along the first layers 1f-1j is set to 80% or less of the area of ​​the second layers 2f-2j in the direction along the second layers 2f-2j, which makes it easier to detect the shear component of the force, and allows the shear component of the force to be determined more accurately.

[0157] In this case, the area of ​​the first layers 1f to 1j in the direction along the first layers 1f to 1j is, for example, 100 mm ２ More than 1000mm ２ The area of ​​the second layers 2f to 2j in the direction along the second layers 2f to 2j is, for example, 125 mm ２ Over 1200mm ２In this case, the total thickness of the first layers 1f to 1j and the second layers 2f to 2j is, for example, about 0.3 mm or more and 3 mm or less.

[0158] 15A and the second layer 2g in Fig. 15B are configured in a frustum shape (a circular truncated cone, a polygonal truncated pyramid, etc.). That is, the second layers 2f and 2g have a shape in which the diameter (around the Z axis) gradually decreases from the pressure distribution sensor 3 side (lower side) to the first layer 1 side (upper side).

[0159] By forming the second layer 2 in this shape, the shear component of the force is more easily reflected in the pressure distribution waveform W, making it easier to detect the shear component of the force than the gradient component of the force, and as a result, the shear component of the force can be determined more accurately.

[0160] The first layer 1 can be formed in a hemispherical shape with the bottom side facing up, as shown in first layer 1f of Fig. 15A, or in a hemispherical shape with the top side facing up, as shown in first layer 1j of Fig. 15E.

[0161] Fourth Embodiment (Detecting the gradient component of a force as the shape of an object) In the above description, the gradient component of a force is detected as the gradient of the object applying the force. However, the gradient component of a force can also be detected as the shape of the object applying the force. This will be described in the fourth embodiment. Note that in the fourth embodiment, a shear component is detected, just like in the first embodiment.

[0162] Fig. 16 is a diagram showing the sensor unit 12 according to the fourth embodiment. The left side of Fig. 16 shows the state when the sensor unit 12 is pressed downward by an object having an acute angle at its tip, and also shows the pressure distribution waveform W at this time. The right side of Fig. 16 shows the state when the sensor unit 12 is pressed downward by an object having an acute angle at its tip and then the object moves (shears) in a planar direction, and also shows the pressure distribution waveform W at this time.

[0163] 16, when the sensor unit 12 is pressed downward by an object having an acute angle on its tip side, this acute angle appears as a gradient component of the force in a first region R in the pressure distribution waveform W. In the fourth embodiment, this relationship is utilized to detect the shape of the object applying force to the sensor unit 12 from the gradient component of the force that appears in the first region R.

[0164] In the case of a configuration in which the shape of an object is detected from the force gradient component as in the fourth embodiment, the first layer 1k is configured to be softer than the second layer 2. Typically, the first layer 1k is configured to be a layer (deformable layer, stretchable layer) that is more easily deformed and stretchable than the second layer 2.

[0165] The material used for the second layer 2 is typically the same as that used in the first embodiment, such as elastomer, gel, soft rubber, etc. On the other hand, the material used for the first layer 1k is selected to be softer than these materials so that it can deform appropriately according to the shape of the object to which force is applied. Examples of such materials include foam material, elastomer, gel, soft rubber, etc.

[0166] In this way, by configuring the first layer 1k to be softer than the second layer 2, the shape of the object can be detected with high accuracy from the gradient component of the force.

[0167] <<Various Modifications>> The present technology may also have the following configurations. (1) A pressure detection device comprising: a pressure distribution sensor capable of detecting a force that may include a gradient component as a pressure distribution waveform; a first layer disposed on the side opposite to the pressure distribution sensor where the force is applied; a second layer interposed between the pressure distribution sensor and the first layer and having a hardness different from that of the first layer; and a control unit that calculates the gradient component based on the pressure distribution waveform. (2) The pressure detection device described in (1) above, wherein the pressure distribution sensor is capable of detecting a force that may include a shear component as a pressure distribution waveform, and the control unit calculates the shear component based on the pressure distribution waveform. (3) The pressure detection device according to (2) above, wherein the control unit separates the pressure distribution waveform into a first region where the slope component is relatively dominant and a second region where the shear component is relatively dominant, calculates the slope component based on the first region, and calculates the shear component based on the second region. (4) The pressure distribution detection device according to (3) above, wherein the control unit sets a region of the pressure distribution waveform where the pressure value is equal to or greater than a predetermined threshold as a first region, and sets a region where the pressure value is less than the predetermined threshold as a second region. (5) The pressure detection device according to (4) above, wherein the control unit variably controls the predetermined threshold. (6) The pressure detection device according to (5) above, wherein the control unit acquires image data including the pressure distribution waveform, and performs image processing on the image data to set the predetermined threshold. (7) The pressure detection device according to (6) above, wherein the image processing is edge extraction processing. (8) The pressure detection device according to any one of (4) to (7) above, wherein the control unit calculates a tilt angle of the first region with respect to a direction parallel to the pressure distribution sensor, and calculates the tilt component based on the tilt angle.(9) The pressure detection device according to any one of (4) to (8), wherein the control unit calculates a movement distance of the second region in a direction parallel to the pressure distribution sensor, and calculates the shear component based on the movement distance. (10) The pressure detection device according to any one of (1) to (9), wherein the second layer is softer than the first layer. (11) The pressure detection device according to any one of (1) to (9), wherein the first layer is softer than the second layer. (12) The pressure detection device according to any one of (1) to (10), wherein an area of ​​the first layer in a direction along the first layer is larger than an area of ​​the second layer in a direction along the second layer. (13) The pressure detection device according to (12) above, wherein the area of ​​the first layer is 125% or more of the area of ​​the second layer. (14) The pressure detection device according to any one of (2) to (10) above, wherein the area of ​​the first layer in a direction along the first layer is smaller than the area of ​​the second layer in a direction along the second layer. (15) The pressure detection device according to (14) above, wherein the area of ​​the first layer is 80% or less of the area of ​​the second layer. (16) The pressure detection device according to any one of (1) to (10), (12), and (13) above, wherein the second layer has an inverted frustum shape. (17) The pressure detection device according to any one of (2) to (10), (14), and (15) above, wherein the second layer has a frustum shape. (18) A pressure detection device including a control unit that separates a pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a gradient component and a shear component as a pressure distribution waveform into a first region where the gradient component is relatively dominant and a second region where the shear component is relatively dominant, calculates the gradient component based on the first region, and calculates the shear component based on the second region.(19) An electronic device comprising a pressure detection device including a pressure distribution sensor capable of detecting a force that may include a gradient component as a pressure distribution waveform, a first layer arranged on the side opposite to the pressure distribution sensor where the force is applied, a second layer interposed between the pressure distribution sensor and the first layer and having a hardness different from that of the first layer, and a control unit that calculates the gradient component based on the pressure distribution waveform. (20) An information processing method that separates the pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a gradient component and a shear component as a pressure distribution waveform into a first region where the gradient component is relatively dominant and a second region where the shear component is relatively dominant, calculates the gradient component based on the first region, and calculates the shear component based on the second region.

[0168] REFERENCE SIGNS LIST 1... First layer 2... Second layer 3... Pressure distribution sensor 10... Pressure detection device 11... Control unit 12... Sensor unit 10... Pressure detection device R... First region R'... Second region W... Pressure distribution waveform

Claims

1. A pressure detection device comprising: a pressure distribution sensor capable of detecting a force that may include a gradient component as a pressure distribution waveform; a first layer arranged on the side opposite to the pressure distribution sensor where the force is applied; a second layer interposed between the pressure distribution sensor and the first layer and having a hardness different from that of the first layer; and a control unit that calculates the gradient component based on the pressure distribution waveform.

2. A pressure detection device according to claim 1, wherein the pressure distribution sensor is capable of detecting a force that may include a shear component as a pressure distribution waveform, and the control unit calculates the shear component based on the pressure distribution waveform.

3. A pressure detection device according to claim 2, wherein the control unit separates the pressure distribution waveform into a first region where the gradient component is relatively dominant and a second region where the shear component is relatively dominant, calculates the gradient component based on the first region, and calculates the shear component based on the second region.

4. A pressure distribution detection device according to claim 3, wherein the control unit sets a region of the pressure distribution waveform where the pressure value is equal to or greater than a predetermined threshold as a first region, and sets a region where the pressure value is less than the predetermined threshold as a second region.

5. A pressure detection device according to claim 4, wherein the control unit variably controls the predetermined threshold value.

6. A pressure detection device according to claim 5, wherein the control unit acquires image data including the pressure distribution waveform, and performs image processing on the image data to set the predetermined threshold value.

7. A pressure detection device according to claim 6, wherein the image processing is edge extraction processing.

8. A pressure detection device according to claim 4, wherein the control unit calculates the tilt angle of the first region with respect to a direction parallel to the pressure distribution sensor, and calculates the tilt component based on the tilt angle.

9. A pressure detection device according to claim 4, wherein the control unit calculates the movement distance of the second region in a direction parallel to the pressure distribution sensor, and calculates the shear component based on the movement distance.

10. A pressure sensing device according to claim 1, wherein the second layer is softer than the first layer.

11. The pressure sensing device according to claim 1, wherein the first layer is softer than the second layer.

12. A pressure detection device according to claim 1, wherein the area of ​​the first layer in a direction along the first layer is larger than the area of ​​the second layer in a direction along the second layer.

13. A pressure detection device according to claim 12, wherein the area of ​​the first layer is 125% or more of the area of ​​the second layer.

14. A pressure detection device according to claim 2, wherein the area of ​​the first layer in a direction along the first layer is smaller than the area of ​​the second layer in a direction along the second layer.

15. A pressure detection device according to claim 14, wherein the area of ​​the first layer is 80% or less of the area of ​​the second layer.

16. A pressure sensing device according to claim 1, wherein the second layer has an inverted frustum shape.

17. A pressure sensing device according to claim 2, wherein the second layer has a frustum shape.

18. A pressure detection device equipped with a control unit that separates a pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a tilt component and a shear component as a pressure distribution waveform into a first region where the tilt component is relatively dominant and a second region where the shear component is relatively dominant, calculates the tilt component based on the first region, and calculates the shear component based on the second region.

19. An electronic device equipped with a pressure detection device including a pressure distribution sensor capable of detecting a force that may include a gradient component as a pressure distribution waveform, a first layer positioned on the side opposite the pressure distribution sensor where the force is applied, a second layer interposed between the pressure distribution sensor and the first layer and having a hardness different from that of the first layer, and a control unit that calculates the gradient component based on the pressure distribution waveform.

20. An information processing method comprising: separating a pressure distribution waveform detected by a pressure distribution sensor capable of detecting a force that may include a tilt component and a shear component as a pressure distribution waveform into a first region where the tilt component is relatively dominant and a second region where the shear component is relatively dominant; calculating the tilt component based on the first region; and calculating the shear component based on the second region.

Images