JP7419039B2 - Tactile presentation device - Google Patents

Description

The present disclosure relates to a tactile presentation device.

In recent years, electronic devices equipped with touch panels, such as smartphones and car navigation systems, have become popular. When a user operates an object such as an icon included in a user interface displayed via a touch panel, the electronic device activates a function corresponding to the object.

Since the surface of the touch panel is uniformly hard, it provides the same tactile sensation no matter which part of the touch panel the user's finger touches. Therefore, techniques are known that provide feedback to the user, which makes the user perceive the presence of an object or, when a function corresponding to the object is activated, makes the user perceive that an operation for that purpose has been accepted. This technology presents a tactile sensation to a touching finger by vibrating a touch panel in the in-plane direction of the touch panel.

US Patent Application Publication No. 2012/0262394 JP2013-97438A

The inventors discovered that the strength of stimulation perceived by the user changes depending on the relationship between the direction of in-plane vibration of the vibrating surface and the axis of the touching finger. Specifically, it has been found that vibrations in a direction perpendicular to the long axis of the finger (the axis along the direction in which the finger extends) can cause the user to perceive a weaker stimulus than the same vibration in the parallel direction. Ta. When the stimulation applied to the finger weakens, it becomes difficult for the user to perceive a certain tactile sensation (for example, a click sensation).

A tactile presentation device according to an aspect of the present disclosure includes a touch surface having a fixed orientation, an actuator that vibrates the touch surface along one axis within the surface, and controlling the vibration of the actuator along the one axis, a control device that presents a tactile sensation to a finger contacting the touch surface. The control device is configured such that a starting direction of vibration for presenting a tactile sensation to the finger is within a range of -43° to +43° with respect to a direction in which a vertical direction is projected onto the touch surface or the opposite direction. The actuator is controlled as follows.

A tactile presentation device according to another aspect of the present disclosure includes a touch surface, an actuator that vibrates the touch surface along an in-plane axis, and a touch surface that controls vibration of the actuator along the one axis. a control device that presents a tactile sensation to a finger contacting the finger. The control device estimates a direction in which the finger in contact with the touch surface is projected onto the touch surface, and controls the actuator to change the intensity of the vibration according to the projected direction.

A tactile presentation device according to still another aspect of the present disclosure includes a touch surface, a display device whose relative position is fixed with respect to the touch surface, and an actuator that vibrates the touch surface along an in-plane axis. , a control device that controls vibration of the actuator along the one axis to present a tactile sensation to a finger that is in contact with the touch surface. The control device controls the control device so that the starting direction of vibration for presenting a tactile sensation to the finger is within a range of −43° to +43° with respect to the vertical direction of the image displayed on the display device. Control the actuator.

A tactile presentation device according to still another aspect of the present disclosure includes: a touch surface; an actuator that vibrates the touch surface along one axis within the surface; a spring that defines a neutral position of vibration of the touch surface; a control device that controls vibration of the actuator along the one axis to present a tactile sensation to a finger contacting the touch surface. The actuator is a solenoid, the control device applies first and second drive pulses to the solenoid, the voltage amplitudes of the first and second drive pulses are equal, and the width of the second drive pulse is The width is narrower than the width of the first drive pulse.

A tactile sensation presentation device according to one aspect of the present disclosure can present an appropriate tactile sensation to a user's finger touching a vibrating surface.

1 is a diagram illustrating an example of the configuration of an electronic device according to a first embodiment; FIG. In Embodiment 1, a state in which a user's finger touches an area corresponding to an object image on a touch surface of a touch panel is shown. 2 is a flowchart illustrating an example of processing executed by an electronic device in the first embodiment. Embodiment 1 shows a state in which the long axis of the finger and the vibration direction (vibration axis) are substantially parallel. In the first embodiment, a state is shown in which the long axis of the finger and the vibration direction (vibration axis) are substantially perpendicular. In Embodiment 1, the drive voltage applied to the linear solenoid actuator and the vibration of the vibrator in measurement are schematically shown. Indicates the direction of vibration of the actuator used in the measurement. In Embodiment 1, subjective evaluation results in measurements are shown. In the first embodiment, a variance analysis table of the evaluation results shown in FIG. 7 is shown. In Embodiment 1, the relationship between psychological scale values and yard stick Y _0.01 in each of the four vibration directions is shown. In Embodiment 1, a graph of the measurement results is shown, showing the frequency distribution in the vibration direction in which the vibration was felt to be the "strongest" and the frequency distribution in the vibration direction in which the vibration was felt to be the "weakest." In Embodiment 1, a graph of measurement results is shown, and a frequency distribution in a direction of vibration in which vibration is felt to be "strongest" and a normal distribution curve fitted to the frequency distribution are shown. FIG. 3 is a diagram illustrating an example of the configuration of an electronic device according to a second embodiment. 12 schematically shows an example of a logical configuration of a control device according to a third embodiment. In Embodiment 3, an example of the acceleration of the lateral actuator that is controlled by the haptic control unit according to the angle between the long axis of the finger and the in-plane vibration direction is shown. In Embodiment 3, an example of the acceleration of the lateral actuator that is controlled by the haptic control unit according to the angle between the long axis of the finger and the in-plane vibration direction is shown. In Embodiment 3, an example of the acceleration of the lateral actuator that is controlled by the haptic control unit according to the angle between the long axis of the finger and the in-plane vibration direction is shown. In Embodiment 3, another graph of the measurement results described in Embodiment 1 is shown. In embodiment 3, a finger contacting a touch surface and its contact area are shown. In embodiment 3, the contact area of the finger and the axis parallel to the major axis of the ellipse fitted to the contact area are shown. In Embodiment 3, the relationship between the touch surface and the vertical direction (direction of gravity) is shown. In Embodiment 3, a relationship between a user's face image captured by a built-in camera of an electronic device and a touch surface is schematically shown.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. It should be noted that this embodiment is only an example for realizing the present disclosure, and does not limit the technical scope.

<Embodiment 1>
FIG. 1 is a diagram showing an example of the configuration of an electronic device 10 according to the first embodiment. The electronic device 10 (tactile presentation device) includes a tactile presentation panel 100 and a control device 110. The tactile presentation panel 100 and the control device 110 are connected via a connection line.

The tactile presentation panel 100 presents a UI (user interface) including at least one object (image) to the user, and accepts operations via the UI. Further, the tactile presentation panel 100 provides the user with a tactile sense for allowing the user to perceive the operation of an object included in the UI.

The tactile presentation panel 100 includes a touch panel 101, a liquid crystal display 103, a carrier 104, a base 105, a lateral actuator 106, and a leaf spring 107. The components of tactile presentation panel 100 may be housed in any housing, for example. The touch panel 101 and liquid crystal display 103 are configured to realize a display screen that displays a UI, and the carrier 104, lateral actuator 106, and leaf spring 107 are configured to realize mechanical vibration.

The base 105 is a member that serves as the foundation of the tactile presentation panel 100. A lateral actuator 106 and a leaf spring 107 are installed on the base 105 . Further, a carrier 104 is provided on the base 105 and is vibrated by the operation of a lateral actuator 106 and a leaf spring 107. The carrier 104 is vibrated along a specific axis with respect to the base 105 by the lateral actuator 106 (also referred to as lateral motion). The vibration of the carrier 104 realized by the lateral actuator 106 and the leaf spring 107 is a mechanical vibration. In the following description, vibration for tactile presentation is one or more reciprocating movements.

The lateral actuator 106 is a device that generates movement along one axis parallel to the touch surface of the haptic presentation panel 100. The touch surface is the main surface of the touch panel 101 that a finger comes into contact with, and is a tactile presentation surface that presents a tactile sensation to the finger (feedback). The leaf spring 107 is used as a mechanism for generating vibrations in accordance with the movement of the lateral actuator 106. The leaf spring 107 defines a neutral position for vibration of the touch surface. The carrier 104 is a member that serves as a base on which members constituting the display screen are stacked. A liquid crystal display 103 and a touch panel 101 are provided on the carrier 104. FIG. 1 shows an example of the configuration of the tactile presentation panel 100, and the tactile presentation panel 100 may have other configurations. For example, the carrier 104 may be omitted, and the liquid crystal display 103 may be directly connected to the lateral actuator 106 and the leaf spring 107.

The liquid crystal display 103 and the touch panel 101 are installed substantially parallel to the base 105. A touch panel 101 is arranged in front of a liquid crystal display 103. In the following, the side where the user who uses the haptic presentation panel 100 is located will be referred to as the front side. The side opposite the front side is called the back side.

The touch panel 101 detects the position of a user's finger that touches the front surface of the touch panel 101 . Any type of touch panel can be used as the touch panel 101, and for example, a resistive film type, surface capacitance type, or projected capacitance type touch panel can be used. Further, a panel having both the function of a touch panel and the function of presenting a tactile sensation using static electricity may be used.

The liquid crystal display 103 displays a UI image including objects. Any type of display different from a liquid crystal display can be used, for example an OLED (Organic Light Emitting Diode) display or a micro LED display.

Control device 110 can include one or more computing devices that execute programs and one or more storage devices. The arithmetic device can include, for example, a processor, a GPU (Graphics Processing Unit), a FPGA (Field Programmable Gate Array), and the like. The storage device stores programs and data used by the control device 110. Storage devices can include volatile or non-volatile memory. The storage device includes a work area used by the program.

The control device 110 operates as a functional unit (module) for controlling the tactile presentation panel 100. Specifically, the control device 110 operates as a display control section 111 and a tactile control section. The display control unit 111 controls the display of the UI on the display screen. Specifically, the display control unit 111 acquires UI setting information from a storage device, and controls the liquid crystal display 103 based on the information so that a UI including at least one object is displayed.

The touch detection unit 115 detects the contact of the user's finger on the touch panel 101 based on the output from the touch panel 101, and also specifies the touch position of the user's finger on the touch panel 101. For example, when the touch detection unit 115 detects a touch at a position corresponding to a specific object image, it outputs a request to generate mechanical vibration to the tactile control unit 113. The haptic control section 113 controls the lateral actuator 106 in response to the touch detection section 115 to generate mechanical vibrations.

The drive pulse applied to the lateral actuator 106 consists of a first pulse and a second pulse, and the first pulse and the second pulse have the same voltage amplitude. The lateral actuator shifts the touch surface in one direction from the initial state by applying the first pulse, and then starts shifting in the opposite direction and starts reciprocating movement when the application of the first pulse ends.

Subsequently, by applying a second pulse after a predetermined non-application time, the shift is stopped when the touch surface returns to its initial state. In order to present a crisp tactile sensation such as a click sensation to the user, the no-applying time and the second pulse width may be set so that the lateral actuator stops after shifting only one round trip from the initial state. Further, the no-applying time may be set longer than the case of only one reciprocation described above so that the lateral actuator stops after reciprocating a plurality of times from the initial state. In this way, it is possible to present a tactile sensation with a long vibration duration.

Tactile presentation panel 100 may further include a force sensor. The force sensor detects force applied to the user in a direction perpendicular to the main surface of the tactile presentation panel 100 (touch panel 101). The tactile control unit 113 vibrates the lateral actuator 106, for example, when a specific area on the touch panel 101 is touched and the value detected by the force sensor exceeds a threshold value. Regarding each functional unit included in the control device 110, a plurality of functional units may be combined into one functional unit, or one functional unit may be divided into a plurality of functional units for each function.

Next, an example of processing executed by the electronic device 10 will be described. FIG. 2 shows how a user's finger 205 touches an area corresponding to an object image 201 on the touch surface 150 of the touch panel 101. When the user's finger 205 (the same applies to other indicators) touches an area of a specific object image 201, the electronic device 10 causes the touch panel 101 (tactile presentation panel 100) to vibrate in a vibration direction (two directions opposite to each other) 161. make it vibrate. Thereby, for example, a click feeling can be given to the user's finger 205.

FIG. 3 is a flowchart illustrating an example of processing executed by the electronic device 10. The display control unit 111 selects a UI image based on the operating state and the like, and controls the liquid crystal display 103 to display a new UI image (step S101). The display control unit 111 stores, in the storage device, position information of an area of the object image that provides a tactile sensation by in-plane vibration of the touch panel 101.

The touch detection unit 115 executes detection processing (step S102). The detection process detects the touch of a user's finger on the touch panel 101 and specifies the position of the touch area on the touch panel 101. Specifically, the touch detection unit 115 detects a signal indicating a touch of the user's finger from the touch panel 101. For example, the touch detection unit 115 detects a change in capacitance of the touch panel 101 as a signal.

The touch detection unit 115 calculates coordinates indicating the contact position of the user's finger on the touch panel 101. For example, coordinates are calculated based on the position of the electrode where a change in capacitance is detected. The touch detection unit 115 stores the calculated coordinates in a storage device. Touch detection unit 115 notifies tactile control unit 113 that touch panel 101 has been touched.

If the object for tactile presentation is touched (S103: YES), the tactile control unit 113 executes tactile presentation processing (S104). Specifically, upon receiving the notification from the touch detection unit 115, the haptic control unit 113 acquires the position information of the object image presenting the tactile sensation and the position information of the touch area from the storage device, and compares them. . When the touch area at least partially overlaps with the area of the object image, the haptic control unit 113 vibrates the haptic presentation panel 100 (touch panel 101) along one axis in the plane to provide feedback to the user using mechanical vibration. provide.

Specifically, the haptic control unit 113 generates mechanical vibration by controlling the lateral actuator 106. This causes the carrier 104 to vibrate along a specific axis (in a specific direction). A liquid crystal display 103 and a touch panel 101 are installed on the carrier 104, and the liquid crystal display 103 and the touch panel 101 vibrate together with the carrier 104.

The touch detection unit 115 notifies the display control unit 111 that the touch panel 101 has been touched. The display control unit 111 acquires the position information of the touch area from the storage device, and specifies the relationship between the position of the touch area and the currently displayed UI image. If the UI image switching object is selected (S105: YES), the display control unit 111 switches to a new UI image (S101).

Next, presentation of a tactile sensation by the haptic control unit 113 and the lateral actuator 106 will be described. The tactile control unit 113 vibrates the touch panel 101 (tactile presentation panel 100) along one axis along the touch surface (principal surface), thereby giving a tactile sensation (for example, a click sensation) to the touching finger. From the inventors' studies, the tactile sensation felt by the user depends on the angle between the in-plane vibration direction of the touch surface and the long axis of the finger (the axis along the extending finger) when viewed in the normal direction of the touch surface. It was found that the intensity changes. In the following explanation, the angle between the finger axis and the in-plane vibration direction (in-plane vibration axis) is the angle seen in the normal direction of the touch surface, that is, the angle of the finger projected onto the touch surface. means the angle between the axis and the vibration direction (vibration axis).

For example, FIG. 4A shows a state in which the long axis of the finger 205 and the vibration direction 161A (vibration axis) are approximately parallel, that is, the angle between the long axis along the direction in which the finger 205 extends and the vibration direction 161A is approximately 0°. or 180°. FIG. 4B shows a state in which the long axis of the finger 205 and the vibration direction (vibration axis) 161B are approximately perpendicular, that is, the angle between the long axis along the direction in which the finger 205 extends and the vibration direction 161B is approximately 90 degrees or 270 degrees. ° indicates a state. According to the inventors' research, it was found that for the same vibration, the user feels a stronger tactile sensation in the state shown in FIG. 4A than in the state shown in FIG. 4B.

The inventors measured the tactile intensity felt by the user according to the angle between the vibration axis of the tactile presentation panel and the long axis of the finger. The measurement results will be explained below. The device used for the measurement used a linear solenoid actuator as a lateral actuator. FIG. 5 schematically shows the drive voltage applied to the linear solenoid actuator and the horizontal displacement of the touch surface in the measurement. The transducer made one reciprocating motion for one tactile presentation.

In the measurement, a driving voltage as shown in FIG. 5 was applied to the linear solenoid actuator while the finger was touching the touch surface. The linear solenoid actuator gave the evaluator a tactile sensation (click sensation) with one reciprocating motion. Specifically, the linear solenoid actuator shifts the touch surface in one direction from the initial state according to the drive voltage, and then shifts the touch surface in the opposite direction to return to the initial state.

More specifically, the driving voltage used in the measurement was two rectangular wave pulses with a voltage of 13 V. First, a first pulse with a width of 10.0 ms was applied, and then a 4.1 ms period of no application was applied. Then, a second pulse with a width of 2.1 ms, which was shorter than the first pulse, was applied. The linear solenoid actuator shifts the touch surface in one direction from the initial state by applying the first pulse, and then starts shifting in the opposite direction when the application of the first pulse ends. By subsequently applying a second pulse, the shift is stopped when the touch surface returns to its initial state.

That is, in one tactile presentation operation, the touch surface shifts in one direction from the initial state, then shifts in the opposite direction and returns to the initial state. The measurement evaluated the intensity felt by the user due to this one tactile presentation operation. Note that the measurement results described below can also be obtained with any type of lateral actuator capable of imparting similar vibrations.

Figure 6 shows the direction of vibration of the actuator used in the measurements. As shown in FIG. 6, the measurement is performed when the direction in which the vibration (reciprocating motion) starts is 0°, 90°, 180°, and 270° clockwise with the direction from the tip of the finger 205 toward the root as a reference. gave a vibration. A plurality of evaluators subjectively evaluated the strength of vibration at each angle. For evaluation, Scheffe's paired comparison method was used to evaluate the intensity of vibration at a later angle relative to the intensity of vibration at an earlier angle.

FIG. 7 shows the results of subjective evaluation by measurement. The score is 2 if the vibration at the later angle is stronger than the vibration at the previous angle, 1 if the later vibration is slightly stronger, 0 if there is no difference, -1 if the later vibration is slightly weaker, If the subsequent vibration was weak, it was set as -2. The psychological scale value is given by (average evaluation value (before) - average evaluation value (after))/2. FIG. 8 shows a variance analysis table of the evaluation results shown in FIG. From the results of this experiment, it can be seen that there is a significant difference in the "target main effect α" with respect to the "residual error E" at a risk rate of 1%.

FIG. 9 shows the relationship between psychological scale values and yardstick Y _0.01 for each of the four vibration directions. Yard stick Y _0.01 is expressed by the following formula. In the following formula, q is the studentized range, V _E is the unbiased variance of the residual E, m is the number of evaluation subjects (=4), and r is the number of evaluators. This is the number of evaluators in this experiment.

From the evaluation results of the above measurements, vibrations of displacement in the long axis direction of the finger (0° and 180°) and vibrations of displacement in the short axis direction (direction perpendicular to the long axis) of the finger (90° and 270°) are found. A significant difference was observed at a risk rate of 1%. In other words, it was found that vibrations caused by displacement in the direction of the long axis of the finger are perceived to be stronger than vibrations caused by displacement in the direction of the short axis of the finger. On the other hand, no significant difference in perceived intensity was observed between vibrations at 0° and vibrations at 180°.

Furthermore, the inventors investigated the vibration direction in which the user feels the vibration more strongly. The evaluator determined the vibration direction in which the vibration was felt to be the "strongest" and the vibration direction in which the vibration was felt to be the "weakest" through subjective evaluation. The relationship between the strongest vibration direction and the weakest vibration direction determined by each evaluator and the long axis direction of the touched finger was measured.

FIG. 10 shows a graph of the measurement results, showing the frequency distribution in the vibration direction in which the vibration was felt to be the "strongest" and the frequency distribution in the vibration direction in which the vibration was felt to be the "weakest." The graph further shows a normal distribution curve fitted to each frequency distribution. In the graph of FIG. 10, the angle of the vibration direction at which the probability density is reversed (the normal distribution curve intersects) is 43°. If the angle between the starting direction of the reciprocating motion (vibration) and the direction from the tip to the base along the long axis of the finger is in the range of 0° ± 43°, the vibration stimulation is felt to be strong. It turns out that there are many. Further, as described above, since there is no significant difference in perceived intensity between vibrations at 0° and vibrations at 180°, it can be said that the vibrations are similar in the range of 180°±43°.

FIG. 11 shows a graph of the measurement results, showing the frequency distribution in the vibration direction in which the vibration was felt to be the "strongest" and a normal distribution curve fitted to the frequency distribution. The range of the central 50% of the distribution represented by the normal distribution curve is 0°±19°. Vibration stimulation is often felt to be strong when the angle the starting direction of the reciprocating motion makes with the direction from the tip to the base along the long axis of the finger is in the range of 0° ± 19°. Do you get it. As mentioned above, since there is no significant difference in perceived intensity between vibrations at 0° and vibrations at 180°, it can be said that they are similar in the range of 180°±19°.

From the above measurement results, if the angle between the starting direction of the reciprocating motion (vibration) for tactile feedback and one direction along the long axis of the finger is within a predetermined angular range, it indicates a suitable tactile feedback. It turns out that it can be given to Among the many electronic devices in use that include touch panels, there are some electronic devices whose touch surfaces are installed in a fixed orientation and are intended for use by users facing directly toward the touch surface. . ATMs (Automatic Teller Machines) and ticket vending machines installed at stations are examples of such electronic devices.

In electronic devices that are intended to be used by a user facing the device, the user generally touches the touch surface with his or her index finger or middle finger. In addition, the tip of the finger that is in contact with the touch surface generally faces the top edge of the touch surface. The direction approximately corresponds to the direction projected onto .

Therefore, in an example of a tactile presentation device such as an ATM or a ticket issuing machine, which has a fixed touch surface (tactile presentation surface) that is expected to be touched by a user's finger directly facing the user, vibrations for tactile presentation are used. The starting direction is within the range of -43° to +43° with respect to the vertical direction projected onto the touch surface (0°) or the opposite direction (180°). In other words, the vibration axis is within the range of -43° to +43° from the axis obtained by projecting the vertical axis onto the touch surface.

In a more preferred example, the starting direction of the vibration for tactile presentation is in the range of -19° to +19° with respect to the vertical direction projected onto the touch surface (0°) or the opposite direction (180°). It is in. In other words, the vibration axis is within the range of -19° to +19° from the axis obtained by projecting the vertical axis onto the touch surface. With such vibrations, as described above, it is possible to present appropriate tactile sensations to more users.

As described above, the electronic device 10, which is a tactile presentation device, includes a touch surface 150 whose orientation is fixed, a lateral actuator 106 that vibrates the touch surface 150 along one axis within the surface, and a vibrator that vibrates along one axis of the lateral actuator 106. and a control device 110 that controls vibrations to present a tactile sensation to a finger contacting the touch surface.

The control device 110 sets the vibration start direction for presenting a tactile sensation to the finger within a range of -43° to +43° with respect to the direction in which the vertical direction is projected onto the touch surface or the opposite direction. , a lateral actuator may be controlled. The control device 110 also controls the control device 110 so that the starting direction of the vibration for presenting a tactile sensation to the finger is within a range of -19° to +19° with respect to the direction in which the vertical direction is projected onto the touch surface or the opposite direction. The lateral actuator may be controlled as follows.

The above configuration can be applied to devices such as mobile terminals in which the orientation of the touch surface is not fixed, but the orientation of the display screen and its display image is fixed with respect to the touch surface. The orientation of the displayed image relative to the display screen may be fixed, for example, at all times or by default. The direction in which the vertical direction is projected onto the touch surface and the opposite direction can be rephrased as the direction from the top to the bottom of the display image (display screen) and the opposite direction, respectively. In typical use of the device, the top to bottom direction of the displayed image is approximately parallel to the vertical projection onto the display screen. Therefore, this configuration can present an appropriate tactile sensation to the user.

<Embodiment 2>
FIG. 12 is a diagram showing an example of the configuration of the electronic device 10 according to the second embodiment. Description of the same configuration as in the first embodiment will be omitted. The tactile presentation panel 100 includes a touch panel 101, a liquid crystal display 103, a carrier 104, a base 105, a lateral actuator 106, and a leaf spring 107.

A liquid crystal display 103 and a touch panel 101 are provided on the carrier 104. FIG. 12 shows an example of the configuration of the tactile presentation panel 100, and the tactile presentation panel 100 may have other configurations. For example, the carrier 104 may be omitted, and the liquid crystal display 103 may be directly connected to the lateral actuator 106 and the leaf spring 107.

The liquid crystal display 103 and the touch panel 101 are installed substantially parallel to the base 105. A touch panel 101 is arranged in front of a liquid crystal display 103. In the following, the side of the tactile presentation panel 100 on which the UI is presented will be referred to as the front side. The side opposite the front side is called the back side.

The touch panel 101 may be fixed to the liquid crystal display 103 with an adhesive (OCA or OCR) and the touch panel 101 may be displaced together with the liquid crystal display 103, or the touch panel 101 and the liquid crystal display 103 may be separated and only the touch panel 101 may be displaced. It can also be a configuration.

The liquid crystal display 103 displays a UI image including objects. As the liquid crystal display 103, a liquid crystal display may be used as in the first embodiment, or any type of display different from a liquid crystal display, such as an OLED display or a micro LED display, may be used.

The control device 110 includes a display direction determining section 116 in addition to the components of the first embodiment. The display direction determination unit 116 detects the tilt of the electronic device 10 and determines the vertical direction of the UI image (display) with respect to the display screen. As a method for the display direction determining unit 116 to determine the vertical direction of the display, for example, a conventional technique using a triaxial acceleration sensor that senses acceleration in three axial directions can be used. The display control unit 111 controls the liquid crystal display 103 based on the determination result of the display direction determination unit 116 to display a UI image on the display screen.

When using an electronic device that includes a touch panel and accepts operations via a UI displayed on a display screen, as in Embodiment 2, the user generally points the tip of his or her finger toward the top of the display image on the touch surface. Contact. That is, the direction in which the direction from the tip of the finger to the base is projected onto the touch surface substantially coincides with the vertical direction of the display.

Therefore, from the measurement results described in Embodiment 1, when providing suitable tactile feedback to the user's finger, the touch surface (tactile presentation surface) on which the user's touch operation is expected to be performed on the UI displayed on the display screen is In the example of the tactile presentation device, the starting direction of vibration for tactile presentation is from −43° to +43° with respect to the direction from the top to the bottom of the displayed image (0°) or the opposite direction (180°). within the range of °. In other words, the vibration axis is within the range of -43° to +43° from the axis 102 in the vertical direction of the display.

In a more preferred example, the starting direction of the vibration for tactile presentation is in the range of -19° to +19° with respect to the direction from top to bottom of the displayed image (0°) or the opposite direction (180°). It's within. That is, the vibration axis is within the range of -19° to +19° from the axis 102 in the vertical direction of the display. With such vibrations, as in the first embodiment, it is possible to present appropriate tactile sensations to more users.

As described above, the electronic device 10, which is a tactile presentation device, includes a touch surface, a liquid crystal display 103 whose position relative to the touch surface is fixed, and a lateral actuator that vibrates the touch surface along one axis within the surface. 106 and a controller 110 that controls vibrations of the lateral actuator 106 along one axis to present a tactile sensation to a finger contacting the touch surface.

The control device 110 sets the vibration start direction for presenting a tactile sensation to the finger within a range of -43° to +43° with respect to the direction from the top to the bottom of the displayed image or the opposite direction. , a lateral actuator may be controlled. The control device 110 also controls the control device 110 so that the starting direction of the vibration for presenting a tactile sensation to the finger is within a range of -19° to +19° with respect to the direction from the top to the bottom of the displayed image or the opposite direction. The lateral actuator may be controlled as follows.

Note that the display device of this embodiment has a configuration in which the tilt of the electronic device 10 is variable and the vertical direction of the display changes. In this case, the vibration direction is also changed in accordance with the change in the display direction. To achieve this, for example, the movable part (carrier) can be configured to vibrate along a plurality of axes parallel to the touch surface using the conventional technology described in Japanese Patent No. 6489120. Alternatively, in FIG. 12, this can be achieved by adding a second base equipped with an actuator to the front or rear side of the base 105 so as to vibrate in a direction perpendicular to the vibration direction of the lateral actuator 106.

<Embodiment 3>
As described in the first embodiment, the perceived tactile intensity changes depending on the angle between the in-plane vibration direction of the tactile presentation panel and the long axis of the finger. Specifically, the tactile intensity is strong when the vibration direction is parallel to the long axis of the finger, and weak when the vibration direction is perpendicular to the long axis of the finger. Furthermore, as the vibration direction changes from parallel to the long axis of the finger to perpendicular to it, the tactile intensity decreases.

The tactile presentation device of this embodiment estimates the direction in which a finger in contact with the touch surface is projected onto the touch surface, and controls the intensity of lateral motion based on the estimated direction. When the intensity of the in-plane vibration increases, the intensity of the tactile sensation (stimulus) perceived by the user from the finger increases when the angle of the finger is fixed. The tactile presentation device can increase or decrease the vibration intensity by, for example, increasing or decreasing the displacement (amplitude), speed, and/or acceleration of the vibration.

FIG. 13 schematically shows an example of the logical configuration of the control device 110 of this embodiment. In addition to the components of the first embodiment, a finger direction estimation unit 117 is included. The finger direction estimation unit 117 detects the direction of the long axis of the finger in contact with the touch surface or the angle between the in-plane vibration axis and the long axis of the finger, and estimates the direction of the finger. An example of how the finger direction estimation unit 117 detects the direction of the long axis of the finger will be described later. The haptic control unit 113 controls the lateral actuator 106 based on the direction of the long axis of the finger detected by the finger direction estimation unit 117.

14A, 14B, and 14C each show an example of the acceleration of the lateral actuator 106 controlled by the haptic control unit 113 depending on the angle between the long axis of the finger and the in-plane vibration direction. In the graphs of FIGS. 14A, 13B, and 13C, the horizontal axis indicates the angle between the long axis of the finger and the in-plane vibration axis, respectively. The vertical axis shows acceleration. Therefore, for each angle other than 0° and 180°, there are two directions of the long axis of the finger. As described in the first embodiment, the finger direction estimation unit 117 detects the angle between the vibration start direction and the direction from the tip to the base of the finger, and the tactile control unit 113 detects the angle between the detected angle (0° to The vibration intensity of the lateral actuator 106 may be controlled depending on the angle (360°).

The control example shown in FIG. 14A gives the minimum acceleration at 0° and 180°, where stimulation is easy to perceive, and gives the maximum acceleration at 90°, where stimulation is difficult to perceive. Acceleration increases proportionally from 0° to 90° and decreases proportionally from 90° to 0°. In the example of FIG. 14A, the proportionality constants of increase and decrease are the same, but they may be different.

The control example shown in FIG. 14B gives the minimum acceleration at 0° and 180°, where stimulation is easy to perceive, and gives the maximum acceleration at 90°, where stimulation is difficult to perceive. The acceleration is constant from 0° to 19°, increases proportionally from 19° to 69°, and is constant from 69° to 90°. Further, the acceleration is constant from 90° to 111°, decreases proportionally from 111° to 161°, and is constant from 161° to 180°. In the example of FIG. 14B, the change in acceleration is symmetrical about 90°. Note that the proportional coefficients of increase and decrease may be different.

The angles 19° and 161° correspond to the values that define the range in which the vibration stimulation is felt to be stronger than other angles, as described in the first embodiment. The angles 69° and 111° are determined as follows. FIG. 15 shows another graph of the measurement results described in the first embodiment. The graph shows the frequency distribution in the vibration starting direction where the vibration was felt to be the "weakest" and a normal distribution curve fitted to the frequency distribution. The range of the central 50% of the distribution represented by the normal distribution curve is 90°±21°. In this range, vibration stimulation is often felt to be weak. Therefore, the highest acceleration in this range is given. The same can be said for −90°±21°, since no significant difference in perceived intensity was observed between vibrations at 90° and 270°.

The control example shown in FIG. 14C gives the minimum acceleration at 0° and 180°, where stimulation is easy to perceive, and gives the maximum acceleration at 90°, where stimulation is difficult to perceive. The acceleration increases from 0° to 90° and decreases from 90° to 180°. The rate of increase/decrease in acceleration is not constant, but follows a predetermined function. In the example of FIG. 14C, the change in acceleration is shown as a curve. In the example of FIG. 14C, the change in acceleration is symmetrical about 90°, but may be asymmetrical.

As described above, the control device 110 controls the lateral actuator 106 so that when the direction in which the finger is projected onto the touch surface is perpendicular to the vibration axis of the lateral actuator 106, the vibration intensity is stronger than when the direction is parallel. can be controlled. Further, as in the examples of FIGS. 14A, 14B, and 14C, the control device 110 controls the lateral actuator 106 to gradually increase the vibration intensity from a direction parallel to the vibration to a direction perpendicular to the vibration in a specific direction range. You can.

Next, an example of a method for detecting the direction of the long axis of a finger will be described. One known method estimates the direction of a finger from the contact surface of the finger on the touch surface 150 of the touch panel 101. For example, the touch panel 101 is a capacitive touch panel. FIG. 16A shows finger 205 and its contact area 220 contacting touch surface 150. The touch detection unit 115 stores information about the shape of the contact area 220 of the finger 205 in the storage device.

The finger direction estimation unit 117 acquires information about the contact area 220 from the storage device, and fits an ellipse to the contact area 220. The finger direction estimating unit 117 estimates that the major axis of the fitted ellipse is parallel to the major axis of the finger. FIG. 16B shows the contact area 220 of the finger 205 and the axis 225 parallel to the major axis of the ellipse fitted to the contact area 220. The finger direction estimation unit 117 stores information about the angle of the axis 225 on the touch surface 150 in the storage device. The haptic control unit 113 controls the lateral actuator 106 based on the angle θ between the vibration axis 165 on the touch surface 150 and the estimated long axis 225 of the finger.

The finger direction estimating unit 117 may determine the direction from the tip of the finger toward the root of the finger on the axis 225. For example, when the touch surface 150 is fixed like the ATM machine or ticket vending machine described in Embodiment 1, the direction is a reference direction predefined on the touch surface 150, for example, from the upper side to the lower side of the touch surface 150. The direction from the tip to the root of the finger may be determined by referring to the direction. Furthermore, as will be described later, when the electronic device 10 is portable and the orientation of (the reference direction of) the touch surface 150 with respect to the vertical direction can be determined, the finger direction estimation unit 117 Based on this, the direction from the tip to the base of the finger can be determined.

Another method for detecting the direction of the long axis of the finger is to estimate the direction of the finger projected onto the touch surface 150 based on the output of a three-axis acceleration sensor (gravity sensor) installed in the electronic device 10. FIG. 17 shows the relationship between the touch surface 150 and the vertical direction (direction of gravity). The electronic device 10 is a mobile terminal, and the user can freely change its orientation.

As shown in FIG. 17, the touch surface 150 is defined as an xy plane, and the normal to the touch surface 150 is defined as the z-axis. In this example, the vibration direction 161 (vibration axis) of the lateral actuator 106 is parallel to the y-axis. The gravity detected by the acceleration sensor mounted on the electronic device 10 is represented by a vector g. The finger direction estimation unit 117 can estimate the orientation of the touch surface 150 with respect to the vector g from the acceleration values of each of the three axes. The finger direction estimation unit 117 estimates the xy plane component g _xy of the vector g to be the direction from the tip to the base of the touched finger.

The haptic control unit 113 controls the lateral actuator 106 based on the angle θ (0° to 180°) between the xy plane component g _xy and the y axis. As described in the first embodiment, the haptic control unit 113 specifies the angle between the xy plane component g _xy and the vibration start direction along the y axis within a range of 0° to 360°, and The lateral actuator 106 may be controlled based on.

Another method for detecting the direction of the long axis of the finger is to estimate the direction of the finger projected onto the touch surface based on the direction of the user's face captured by a camera installed in the electronic device 10. FIG. 18 schematically shows the relationship between the user's face image 230 captured by the built-in camera 108 of the electronic device 10 and the touch surface 150.

The finger direction estimation unit 117 performs recognition processing on the user's face image 230 captured by the camera 108 and determines the vertical axis 235 of the face image 230. The axis 235 can be identified, for example, from the positions of the two eyes in the face image 230. Further, the upper and lower sides of the face image 230 along the axis 235 can be identified from the relationship between the eyes and other parts of the face image 230. The finger direction estimation unit 117 stores information on the angle of the axis 235 in the storage device. Also, if necessary, upper and lower face information along axis 235 is stored.

The haptic control unit 113 controls the lateral actuator 106 based on the angle θ (0° to 180°) between the vibration axis 165 on the touch surface 150 and the axis 235 of the face image 230. As described in the first embodiment, the tactile control unit 113 sets the angle between the downward direction of the axis 235 of the face image 230 and the vibration start direction along the vibration axis 165 from 0° to 360°. The angle may be specified within a range, and the lateral actuator 106 may be controlled based on the angle.

Although the embodiments of the present application have been described above, the present disclosure is not limited to the above embodiments. Those skilled in the art can easily change, add, or convert each element of the above embodiments within the scope of the present disclosure. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

10 electronic device, 100 tactile presentation panel, 101 touch panel, 103 liquid crystal display, 104 carrier, 105 base, 106 lateral actuator, 107 leaf spring, 108 camera, 110 control device, 111 display control unit, 113 tactile control unit, 115 touch detection part, 117 finger direction estimation part, 150 touch surface, 161, 161A, 161B vibration direction, 165 vibration axis, 201 object image, 205 finger, 220 contact area, 225 long axis, 230 face image, 235 vertical axis of face image

Claims (3)

A touch surface with a fixed orientation,
an actuator that vibrates the touch surface along one axis within the surface;
a control device that controls vibration of the actuator along the one axis to present a tactile sensation to a finger in contact with the touch surface during a selection operation of an object displayed on the touch surface ;
including;
The control device is configured such that a starting direction of vibration for presenting a tactile sensation to the finger is within a range of -43° to +43° with respect to a direction in which a vertical direction is projected onto the touch surface or the opposite direction. controlling the actuator so as to
Tactile presentation device. The tactile presentation device according to claim 1,
The control device is configured such that a starting direction of vibration for presenting a tactile sensation to the finger is within a range of -19° to +19° with respect to a direction in which a vertical direction is projected onto the touch surface or the opposite direction. controlling said actuator so as to
Tactile presentation device. The tactile presentation device according to claim 1,
The control device applies drive pulses with different pulse widths to the actuator in order to generate the vibration.
Tactile presentation device.

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