Stylus pen and input system

Abstract

The present invention provides a stylus pen capable of presenting a tactile sensation with a realistic feeling of writing, and an input system.　A stylus pen (100) comprises a pen body (100A), a vibration element (150) provided in the pen body, and a control unit (130) that generates a drive signal for driving the vibration element. The control unit generates the drive signal such that vibration of the pen body caused by drive of the vibration element becomes a vibration based on an impulse response.

Description

Stylus pen and input system

[0001] The present disclosure relates to a stylus pen and an input system.

[0002] A conventional vibration system includes a linear vibration motor and a control unit that controls a drive current waveform of the vibration motor. The drive current waveform is configured by a series of large unit waves, each having the same waveform, arranged on a time axis. The large unit waves have a first region having a small amplitude waveform over one period T, which is the width of the large unit waves on the time axis, and a second region having a large amplitude waveform that is larger than the first region. The first region and the second region alternate on the time axis. The vibration system generates vibrations in a stylus pen (see, for example, Patent Document 1).

[0003] JP 2019-066960 A

[0004] However, conventional vibration systems used in stylus pens do not drive the vibration motor (vibration element) based on the vibration transmitted to the hand when actually writing, such as when writing characters on paper with an ink-type ballpoint pen, but drive the vibration motor (vibration element) with a vibration pattern that simulates the vibration when writing. For this reason, it is difficult for stylus pens using conventional vibration systems to present a tactile sensation similar to that of actually writing.

[0005] Therefore, an object of the present invention is to provide a stylus pen and an input system that can provide a realistic tactile sensation of writing.

[0006] A stylus pen according to an embodiment of the present disclosure comprises a pen body, a vibration element provided in the pen body, and a control unit that generates a drive signal to drive the vibration element, and the control unit generates the drive signal so that vibration of the pen body due to driving of the vibration element is based on an impulse response.

[0007] An input system according to an embodiment of the present disclosure is an input system including a stylus pen and a detection device that detects contact of the stylus pen with an operation surface, and is equipped with a vibration element and a control unit that generates a drive signal to drive the vibration element, and the control unit generates the drive signal so that vibration of the stylus pen due to driving of the vibration element is based on an impulse response.

[0008] It is possible to provide a stylus pen and an input system that can provide a realistic tactile sensation of writing.

[0009] 1 is a diagram showing an example of a usage state of a stylus pen of an embodiment; FIG. 1 is a diagram showing an example of a mechanical model combining a finger and a pen body; FIG. 2 is a diagram showing an example of how a vibration waveform is measured; FIG. 3 is a diagram showing an example of measurement results of a vibration waveform representing vibrations generated in a ballpoint pen by writing; FIG. 4 is a diagram showing an example of measurement results of a vibration waveform representing vibrations generated in a ballpoint pen by writing; FIG. 5 is a diagram showing an example of measurement results of acceleration, writing angular velocity, and writing pressure generated in a ballpoint pen over time; FIG. 6 is a diagram showing an example of time characteristics and frequency characteristics of acceleration of an impulse response estimated by an AR model; FIG. 7 is a diagram showing an example of time characteristics and frequency characteristics of acceleration of an impulse response estimated by an ARMA (prony's method) model; FIG. 8 is a diagram showing an example of time characteristics and frequency characteristics of acceleration of vibration estimated by an ARMA (Steiglitz-Mcbride method) model; FIG. 9 is a diagram showing an example of characteristics of the average frequency and normalized standard deviation of vibration with respect to the writing angular velocity; FIG. 10 is a diagram showing an example of characteristics of the average wave height and the ratio of standard deviation / average wave height of acceleration of vibration with respect to the writing angular velocity; FIG. 11 is a histogram showing an example of the variance of vibration acceleration; FIG. 12 is a diagram showing an example of time changes in writing angular velocity and vibration acceleration. FIG. 2 is a block diagram showing the internal configuration of the stylus pen according to the embodiment.

[0010] Hereinafter, an embodiment to which the stylus pen and input system of the present disclosure are applied will be described.

[0011] In the following description, the XYZ coordinate system is defined. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to each other. For ease of explanation, the -Z direction side may be referred to as the lower side or bottom, and the +Z direction side as the upper side or top, but this does not represent a universal vertical relationship. Furthermore, a planar view refers to a view from an XY plane.

[0012] In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. Furthermore, terms such as parallel, up and down, etc., may be misaligned to the extent that the effect of the embodiment is not impaired.

[0013] 1A is a diagram showing an example of a state in which a stylus pen 100 according to an embodiment is in use. Fig. 1A shows a tablet computer 200 that can be operated with the stylus pen 100. The tablet computer 200 has an operation surface 200A. Operation surface 200A is, for example, the surface of a top panel that is placed over a liquid crystal display. For example, an electrostatic sensor that can detect the coordinates of an operation position on operation surface 200A may be provided between the liquid crystal display and the top panel.

[0014] The user holds the stylus pen 100 in the hand H and operates the tablet computer 200 by touching the tip of the stylus pen 100 to the operation surface 200A of the tablet computer 200.

[0015] The stylus pen 100 has a pen body 100A. The pen body 100A is the part of the pen that is visible from the outside of the stylus pen 100, and includes a tip 100A1 and a cap 100A2. The stylus pen 100 includes a vibration element, a driver, a control unit, a gyro sensor, a pen pressure sensor, a battery, etc. inside the pen body 100A, but these are omitted from FIG. 1A .

[0016] If we consider such a system from the stylus pen 100 to the hand H as an approximation to a mechanical model, it can be represented as an elastic mechanical model due to the presence of springs and dampers between the fingers F of the hand H and the pen body 100A.

[0017] 1B is a diagram showing an example of a mechanical model combining a finger F and a pen body 100A. As shown in FIG. 1B, the mechanical model of the finger F and the pen body 100A can be expressed as a mechanical model including an object with a mass m (kg), a spring with a spring constant k (N / m), and a damper with a viscous resistance d (N / sec / m). The mass m is the equivalent mass of the stylus pen 100 and the finger F.

[0018] Here, the tip 100A1 of the pen body 100A is treated as having high rigidity like a ballpoint pen, but if the tip has low rigidity like a felt-tip pen, fountain pen, or writing brush, the tip 100A1 will also have a spring and damper, so the mechanical model will be two mechanical models connected in series as shown in Figure 1B.

[0019] <Measurement of vibration waveform> Fig. 2A is a diagram showing an example of how to measure a vibration waveform. As shown in Fig. 2A, a sheet of paper 2 was placed on the upper surface of a flat plate 1 having a step 1A on its upper surface, and with the tip of a ballpoint pen 10 in contact with the surface of the sheet of paper 2, an operator wrote a straight line with the ballpoint pen 10, and the vibration waveform generated in the ballpoint pen 10 was measured.

[0020] The time-varying characteristics of the acceleration of the vibrations generated in the ballpoint pen 10 when writing were measured as a vibration waveform, because the vibration waveform generated in the ballpoint pen 10 when writing can be expressed as the time-varying characteristics of the acceleration of the vibrations generated in the ballpoint pen 10 when writing.

[0021] An acceleration sensor was attached to the tip of the ballpoint pen 10, and the vibration waveform was measured by detecting the acceleration of the vibration generated in the ballpoint pen 10 while writing with the acceleration sensor. Note that drawing a diagram or the like with the ballpoint pen 10 is considered to be writing. This is also true for a stylus pen.

[0022] 2B and 2C are diagrams showing examples of measurement results of vibration waveforms that represent vibrations generated in the ballpoint pen 10 due to writing. In Fig. 2B and Fig. 2C, the horizontal axis represents time (seconds) and the vertical axis represents vibration acceleration (G). Fig. 2B shows acceleration in the X direction, and Fig. 2C shows acceleration in the Y direction. The X direction is the same as the direction in which a straight line is written with the ballpoint pen 10.

[0023] 2B and 2C, the acceleration rises in a pulse-like manner from approximately 0.08 seconds to approximately 0.11 seconds after the tip of the ballpoint pen 10 passes over the step 1A. Furthermore, even when the writing speed is changed, the waveform shape in the time direction remains approximately the same, indicating that the vibration of the ballpoint pen 10 is an impulse response. This is thought to be the same for a stylus pen with a highly rigid tip 100A1. It is also thought to be the same for felt-tip pens, fountain pens, or writing brushes with less rigid tips.

[0024] <Internal Model Estimation for Realizing Impulse Response> Figure 3 is a diagram showing an example of measurement results of the changes over time in acceleration, writing angular velocity, and writing pressure that occur in the ballpoint pen 10 when drawing a straight line on ordinary paper with few steps. The acceleration, writing angular velocity, and writing pressure shown in Figure 3 are actual measured values. The writing angular velocity is an example of writing speed.

[0025] The acceleration is the acceleration of vibrations that occur in the ballpoint pen 10 when writing, and the vibration waveform was measured by attaching an acceleration sensor to the pen tip of the ballpoint pen 10. The writing angular velocity is the angular velocity that occurs in the ballpoint pen 10 when writing, and was measured by attaching a gyro sensor to the ballpoint pen 10. The gyro sensor is preferably located in a position that does not come into contact with the hand when the ballpoint pen 10 is held in the hand, and as an example, it was attached to the cap side.

[0026] The writing pressure is the pressure with which the pen tip of the ballpoint pen 10 presses against the paper 2 when writing, and was measured by writing with the flat plate 1 mounted on a load cell (load sensor).

[0027] An internal model realizing the impulse response of the stylus pen 100 was estimated based on the actual measured values ​​of acceleration, writing angular velocity, and writing pressure. Figure 3 shows the results obtained by starting writing with the pen stationary at time 0 second and writing linearly up to 1.2 seconds. Here, the acceleration section from 0.4 seconds to 0.8 seconds, where the writing angular velocity is highest, was used as the evaluation section for model estimation. Because the time change characteristics of acceleration are vibration waveforms, the evaluation section was set to the time change characteristics of acceleration.

[0028] In the model estimation, the fluctuation in the force acting between the paper 2 and the ballpoint pen 10 in the writing state was used as the input, and the median value of the force fluctuation was set to 0. In addition, the acceleration of the ballpoint pen 10 in the writing state was used as the output in the model estimation. In the model estimation, the parameters of the spring and damper in the mechanical model of the finger F and the ballpoint pen 10 were set to fixed values ​​that did not fluctuate during writing.

[0029] The internal model was estimated using an autoregressive (AR) model or an autoregressive moving average (ARMA) model. More specifically, the AR model, the ARMA (prony method) model, and the ARMA (Steiglitz-Mcbride method) model were fitted to the input-output relationship.

[0030] Fig. 4A is a diagram showing an example of the time characteristics and frequency characteristics of acceleration of an impulse response estimated by an AR model. Fig. 4B is a diagram showing an example of the time characteristics and frequency characteristics of acceleration of an impulse response estimated by an ARMA (prony's method) model. Fig. 4C is a diagram showing an example of the time characteristics and frequency characteristics of acceleration of an impulse response estimated by an ARMA (Steiglitz-Mcbride method) model. Note that the frequency characteristics are the result of calculating frequency response characteristics from system characteristics obtained by each internal model estimation.

[0031] As can be seen from the time characteristics of vibration acceleration in Figures 4A to 4C, there is almost no difference between the vibration characteristics obtained using the AR model, the ARMA (prony's method) model, and the ARMA (Steiglitz-Mcbride method) model, confirming that the time characteristics of vibration acceleration can be stably estimated. When comparing the results of estimating the impulse response, i.e., the time characteristics of acceleration, from vibrations occurring during writing using the AR model, the ARMA (prony's method) model, and the ARMA (Steiglitz-Mcbride method) model with the results measured using the method shown in Figure 2A, it can be seen that the time responses are nearly similar. From these results, it can be confirmed that the impulse response obtained using an internal model estimation method, such as the AR model, can be used to estimate the vibration waveform of the ballpoint pen 10 during writing.

[0032] 4A to 4C all show that the vibration acceleration attenuates with increasing frequency. This confirms that a system including the ballpoint pen 10 and the finger F can be represented by a mechanical model such as that shown in FIG. 1B.

[0033] 4A to 4C, the frequency characteristics of the vibration acceleration have one peak at approximately 206 Hz, confirming the existence of one resonant frequency. The fact that the frequency characteristics of the vibration acceleration have one peak indicates that the mechanical model of the system from the stylus pen 100 to the hand H shown in FIG. 1A is one resonant system. This indicates that the mechanical model of the system including the ballpoint pen 10 and the finger F can be expressed by one mechanical model such as that shown in FIG. 1B.

[0034] In addition, in the case of a felt-tip pen, a fountain pen, or a writing brush, which has low rigidity at the tip, the mechanical model of the system combining the felt-tip pen, the fountain pen, or the writing brush with the finger F is a mechanical model in which at least two mechanical models such as those shown in Fig. 1B are connected in series, and therefore it is thought that there will be at least two resonant frequencies. In other words, it is thought that the frequency characteristics of the vibration acceleration shown in Figs. 4A to 4C will have at least two peaks.

[0035] 5A is a graph showing an example of the characteristics of the average frequency and normalized standard deviation of vibration with respect to the writing angular velocity, which are obtained from the measured values ​​of the writing angular velocity shown in FIG.

[0036] The frequency is the interval between adjacent pulses converted to frequency, and the average frequency is, for example, the average value of the frequency in each interval when the time axis is divided into 100 millisecond intervals. The normalized standard deviation is the normalized standard deviation of the average frequency. Furthermore, as an example, the characteristics of the average frequency and normalized standard deviation of vibration with respect to the writing angular velocity shown in FIG. 5A were obtained in the interval from 0 to 0.4 seconds of the actual measured writing angular velocity shown in FIG. 3.

[0037] As shown in Figure 5A, the average frequency tended to increase as the writing angular velocity increased. That is, the higher the writing angular velocity, the higher the average frequency. More specifically, the average frequency increased linearly along the dashed line from approximately 166 Hz at a writing angular velocity of 10 degrees / second to approximately 345 Hz at a writing angular velocity of 45.8 degrees / second.

[0038] Furthermore, as shown in FIG. 5A, even when the writing angular velocity increases, the normalized standard deviation of the average frequency remains substantially constant at about 0.42.

[0039] This indicates that the average frequency tends to increase as the writing angular velocity increases, and the frequency fluctuation range is approximately ±40 Hz to ±80 Hz relative to the average frequency.

[0040] Fig. 5B is a diagram showing an example of the characteristics of the average wave height of vibration acceleration with respect to the writing angular velocity and the ratio of standard deviation to average wave height. The characteristics shown in Fig. 5B are the characteristics of the average wave height of vibration acceleration with respect to the writing angular velocity and the ratio of standard deviation to average wave height, which are obtained from the measured values ​​of vibration acceleration and writing angular velocity shown in Fig. 3. Note that the wave height is the amplitude, and the unit of the average wave height of vibration acceleration is G. As an example, the average wave height of vibration acceleration is the average value of the wave height of vibration acceleration in each section when the time axis is divided into 100 millisecond intervals. The standard deviation is the standard deviation of the average wave height of vibration acceleration. The standard deviation / average wave height is the standard deviation of the average wave height of vibration acceleration divided by the average wave height of vibration acceleration.

[0041] Fig. 5C is a histogram showing an example of the variance of vibration acceleration. Fig. 5C shows the variance of peak values ​​of vibration acceleration obtained from some sections of the evaluation section of vibration acceleration shown in Fig. 3. The horizontal axis in Fig. 5C represents the start of the some section of the evaluation section, with 0 seconds as the start point.

[0042] 5C, it was confirmed that the peak values ​​of the vibration acceleration were dispersed, that is, it was confirmed that the vibration acceleration had randomness with time change.

[0043] 6 is a diagram showing an example of the change over time in the writing angular velocity and the vibration acceleration. The change over time in the writing angular velocity and the vibration acceleration shown in FIG. 6 was calculated from the vibration acceleration and the writing angular velocity shown in FIG.

[0044] As shown in Figure 6, the waveforms of the writing angular velocity and the vibration acceleration are roughly the same, and it was confirmed that the vibration acceleration increases as the writing angular velocity increases. Furthermore, since the vibration acceleration increases as the writing pressure increases, it was confirmed that the vibration acceleration increases as the writing angular velocity and writing pressure increase. Therefore, it was found that it is sufficient to generate a drive signal so that the vibration acceleration increases as the writing angular velocity and writing pressure increase.

[0045] <Internal Configuration of Stylus Pen 100> Fig. 7 is a block diagram showing the internal configuration of the stylus pen 100. The stylus pen 100 includes a gyro sensor 110, a writing pressure sensor 120, a control unit 130, a driver 140, and a vibration element 150. These are housed inside the pen body 100A. The gyro sensor 110 is an example of a speed detection unit. The writing pressure sensor 20 is an example of a writing pressure detection unit.

[0046] The gyro sensor 110 detects the writing angular velocity occurring in the stylus pen 100. The gyro sensor 110 detects the angular velocity (writing angular velocity) when writing. The gyro sensor 110 is connected to the control unit 130 and outputs the detected writing angular velocity to the control unit 130. Furthermore, the gyro sensor 110 may detect the three-dimensional orientation of the stylus pen 100 in addition to the writing angular velocity and output this to the control unit 130.

[0047] The gyro sensor 110 may be located inside the pen body 100A, either closer to the tip 100A1, closer to the cap 100A2, or between the tip 100A1 and the cap 100A2. This is because the angular velocity generated in the pen body 100A during writing is the same at any part of the pen body 100A.

[0048] The writing pressure sensor 120 detects the force (writing pressure) with which the user presses the stylus pen 100 against the paper 2 while holding it with a finger F. The writing pressure sensor 120 is connected to the control unit 130 and outputs the detected writing pressure to the control unit 130. As an example, the writing pressure sensor 120 may be disposed in a position close to the tip 100A1 of the pen body 100A, sandwiched between the pen tip located at the tip 100A1 and the internal structure of the pen body 100A. It is sufficient that the writing pressure sensor 120 can detect the pressure applied to the pen tip.

[0049] The control unit 130 includes a data input unit 131, a waveform generation unit 132, a drive signal generation unit 133, and a memory 134. The control unit 130 is, for example, configured as a microcontroller unit (MCU). The control unit 130 is a computer including a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), an input / output interface, an internal bus, and the like. The data input unit 131, the waveform generation unit 132, and the drive signal generation unit 133 are functional blocks representing the functions of the program executed by the control unit 130. The memory 134 is a functional representation of the memory of the control unit 130. The control unit 130 is not limited to a computer, and may be configured as, for example, a field programmable gate array (FPGA). A portion of the control unit 130 (for example, the drive signal generation unit 133) may be configured as an FPGA.

[0050] The data input unit 131 receives the writing angular velocity and three-dimensional attitude from the gyro sensor 110, and also receives the writing pressure from the writing pressure sensor 120. The data input unit 131 also integrates the writing angular velocity received from the gyro sensor 110 to calculate the writing distance. The data input unit 131 outputs the writing angular velocity, writing distance, writing pressure, and three-dimensional attitude to the waveform generation unit 132. The writing distance is expressed in degrees. The writing distance is the distance over which writing is performed, expressed as an angle.

[0051] The waveform generating unit 132 generates a pulse height (acceleration of vibration) and a pulse interval (frequency) for generating a drive signal based on the writing angular velocity and writing pressure input from the data input unit 131, and outputs an impulse response signal corresponding to the generated pulse height and pulse interval (frequency) to the drive signal generating unit 133. The pulse height (acceleration) and pulse interval (frequency) are data that form the basis of the waveform of the drive signal.

[0052] More specifically, the waveform generating unit 132 obtains a pulse height (vibration acceleration) by multiplying the writing angular velocity by a normal random number and the resultant value by the writing pressure, and generates a pulse height such that the higher the writing angular velocity, the greater the pulse height (vibration acceleration), and the higher the writing pressure, the greater the pulse height (vibration acceleration). Note that random numbers other than normal random numbers may also be used.

[0053] The waveform generating unit 132 also generates a pulse interval (frequency) based on the value obtained by multiplying the writing angular velocity by a normal random number. The waveform generating unit 132 generates a pulse interval (frequency) such that the pulse interval becomes shorter (the frequency becomes higher) as the writing angular velocity increases. This causes the timing of vibration generation to conform to the normal random number. Note that random numbers other than normal random numbers may also be used.

[0054] The waveform generating unit 132 may also correct the writing pressure based on the three-dimensional posture. The waveform generating unit 132 may also calculate the pulse interval from the previous waveform output request to the next waveform output request as the elapsed time from the current writing speed and a normal random number. The waveform generating unit 132 may also calculate the required writing distance from the writing position where the previous waveform output request was made by multiplying the pulse interval calculated from the current writing speed and a normal random number by the current writing speed, and use the result for determination.

[0055] The waveform generating section 132 outputs an impulse response signal corresponding to the generated pulse height and pulse interval (frequency) to the drive signal generating section 133 .

[0056] The drive signal generation unit 133 is realized by, for example, an FIR (Finite Impulse Response) filter or an IIR (Infinite Impulse Response) filter. When an impulse response signal corresponding to a pulse height and a pulse interval (frequency) is input from the waveform generation unit 132, the drive signal generation unit 133 weights and superimposes the currently input signal (current sample signal), the previous sample signal, ..., N (N is an integer of 2 or more) previous sample signals, to generate a drive signal and output it to the driver 140. The drive signal is an impulse response signal with a random pulse height (acceleration of vibration) and pulse interval (frequency).

[0057] The memory 134 stores programs and data used by the waveform generating unit 132 and the drive signal generating unit 133 to execute processing. The memory 134 stores data such as normal random numbers used by the waveform generating unit 132, the relationship between the writing angular velocity and the vibration acceleration, the relationship between the writing pressure and the vibration acceleration, and the relationship between the writing angular velocity and the generation interval (frequency).

[0058] The driver 140 is a drive circuit for the vibration element 150 , and drives the vibration element 150 based on the drive signal input from the drive signal generation unit 133 .

[0059] As an example, a vibration actuator such as an LRA (Linear Resonant Actuator) can be used as the vibration element 150. The vibration element 150 is disposed inside the pen body 100A, and generates vibrations in the pen body 100A when driven by a drive signal. This generates vibrations in the pen body 100A based on an impulse response that realizes vibrations similar to those when writing with the ballpoint pen 10.

[0060] The above describes a configuration in which the stylus pen 100 includes the control unit 130 and the vibration element 150. However, the tablet computer 200 may include at least one of the control unit 130 and the vibration element 150, and may generate vibrations based on an impulse response on the operation surface 200A by driving the vibration element 150 based on the writing speed and writing pressure determined from the change over time in the position where the operation is performed with the stylus pen 100.

[0061] In such a case, a system including the stylus pen 100 and the tablet computer 200 can be considered as an input system. The tablet computer 200 in such an input system is an example of a detection device. The position where an operation is performed with the stylus pen 100 may be detected by an electrostatic sensor in the tablet computer 200. The electrostatic sensor is capable of detecting the coordinates of the operation position on the operation surface 200A. Furthermore, the writing pressure may be detected, for example, by providing the tablet computer 200 with a sensor capable of detecting the operating load applied to the operation surface 200A. In this case, the stylus pen 100 may include a gyro sensor 110 and a writing pressure sensor 120, and the writing angular velocity and writing pressure may be transmitted to the control unit 130 of the tablet computer 200 via wired or wireless communication between the stylus pen 100 and the tablet computer 200.

[0062] Furthermore, in such an input system, the stylus pen 100 may include a control unit 130, the tablet computer 200 may include a vibration element 150, and the control unit 130 of the tablet computer 200 may generate a drive signal and transmit the drive signal to the stylus pen 100 via wired or wireless communication between the stylus pen 100 and the tablet computer 200 to drive the vibration element 150. In this case, the writing angular velocity and writing pressure may be detected on either the stylus pen 100 side or the tablet computer 200 side.

[0063] <Effects> The stylus pen 100 includes a pen body 100A, a vibration element 150 provided in the pen body 100A, and a control unit 130 that generates a drive signal to drive the vibration element 150. The control unit 130 generates the drive signal so that the vibration of the pen body 100A caused by driving the vibration element 150 is vibration based on an impulse response. The vibration generated in the pen when writing on paper 2 with a pen such as the ballpoint pen 10 is represented by an impulse response. Therefore, by generating vibrations based on the impulse response in the pen body 100A, it is possible to present a realistic tactile sensation as if writing with the ballpoint pen 10.

[0064] Therefore, it is possible to provide a stylus pen 100 that can provide a realistic tactile sensation of writing.

[0065] The pen body 100A further includes a gyro sensor 110 (speed detection unit) that detects the writing speed of the pen body 100A, and the control unit 130 generates a drive signal so that the interval between vibrations of the pen body 100A becomes shorter as the writing speed detected by the gyro sensor 110 (speed detection unit) increases. This changes the timing at which vibrations occur according to the writing speed, making it possible to reproduce changes in the timing of the tactile sensation according to the writing speed.

[0066] Furthermore, the control unit 130 generates a drive signal so that the timing of vibration of the pen body 100A follows a normal random number, thereby providing a stylus pen 100 that can generate vibrations with randomness that changes over time and can present a more realistic writing sensation.

[0067] The pen body 100A further includes a gyro sensor 110 (speed detection unit) that detects the writing speed of the pen body 100A, and the control unit 130 generates a drive signal such that the acceleration of the vibration of the pen body 100A increases as the writing speed detected by the gyro sensor 110 (speed detection unit) increases. As a result, the acceleration of the vibration changes according to the writing speed, and it is possible to reproduce changes in the strength of the tactile sensation according to the writing speed.

[0068] The pen body 100A further includes a pen pressure sensor 120 (pen pressure detection unit) that detects the pen pressure applied to the pen body 100A, and the control unit 130 generates a drive signal such that the higher the pen pressure detected by the pen pressure sensor 120 (pen pressure detection unit), the greater the acceleration of the vibration of the stylus pen 100. As a result, the acceleration of the vibration changes according to the pen pressure, and it is possible to reproduce a change in the strength of the tactile sensation according to the pen pressure.

[0069] Furthermore, since the impulse response is based on model estimation using an autoregressive model or an autoregressive moving average model, it is possible to reproduce a realistic tactile sensation as if writing with the ballpoint pen 10, and it is possible to provide a stylus pen 100 that can present a more realistic tactile sensation of writing.

[0070] The resonant frequency of the vibration element 150 is 200 Hz or less. By generating vibrations in the pen body 100A in a frequency band that is easily sensed by the sensory organs of the human skin, it is possible to provide a stylus pen 100 that can more easily reproduce the tactile sensation of writing on paper 2 with the ballpoint pen 10 and present a more realistic tactile sensation of writing.

[0071] The input system includes a stylus pen 100 and a detection device that detects contact of the stylus pen 100 with an operation surface, a vibration element 150, and a control unit 130 that generates a drive signal to drive the vibration element 150, and the control unit 130 generates the drive signal so that vibration of the stylus pen 100 caused by driving the vibration element 150 is vibration based on an impulse response. Vibrations that occur in a pen when writing on paper 2 with a pen such as a ballpoint pen 10 are represented by an impulse response. Therefore, by generating vibrations based on the impulse response in the pen body 100A, a realistic tactile sensation similar to that of writing with the ballpoint pen 10 can be presented.

[0072] Therefore, it is possible to provide an input system that can present a realistic tactile sensation of writing.

[0073] The above describes a stylus pen and an input system according to exemplary embodiments of the present disclosure. However, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0074] This international application claims priority based on Japanese Patent Application No. 2022-197695, filed on December 12, 2022, the entire contents of which are incorporated herein by reference.

[0075] REFERENCE SIGNS LIST 100 Stylus pen 100A Pen body 100A1 Tip 100A2 Cap 110 Gyro sensor (an example of a speed detection unit) 120 Pen pressure sensor (an example of a pen pressure detection unit) 130 Control unit 131 Data input unit 132 Waveform generation unit 133 Drive signal generation unit 134 Memory 140 Driver 150 Vibration element 200 Tablet computer 200A Operation surface

Claims

1. The pen body and A vibration element provided in the pen body; A control unit that generates a drive signal for driving the vibration element; Equipped with The control unit generates the drive signal so that vibration of the pen body due to driving of the vibration element is based on an impulse response.

2. A speed detection unit for detecting a writing speed of the pen body is further provided, The stylus pen according to claim 1 , wherein the control unit generates the drive signal such that an interval between vibrations of the pen body becomes shorter as the writing speed detected by the speed detection unit becomes higher.

3. The stylus pen according to claim 1 , wherein the control unit generates the drive signal so that a timing at which vibration of the pen body occurs follows a normal random number.

4. A speed detection unit for detecting a writing speed of the pen body is further provided, The stylus pen according to claim 1 , wherein the control unit generates the drive signal such that an acceleration of the vibration of the pen body increases as the writing speed detected by the speed detection unit increases.

5. A writing pressure detection unit that detects a writing pressure applied to the pen body is further provided, The stylus pen according to claim 1 , wherein the control unit generates the drive signal such that an acceleration of vibration of the stylus pen increases as the writing pressure detected by the writing pressure detection unit increases.

6. The stylus pen according to claim 1 , wherein the impulse response is an impulse response based on model estimation using an autoregressive model or an autoregressive moving average model.

7. The stylus pen according to claim 1 , wherein the vibration element has a resonance frequency of 200 Hz or less.

8. A stylus pen and a detection device for detecting contact of the stylus pen with an operation surface; An input system comprising: A vibration element; A control unit that generates a drive signal for driving the vibration element; Equipped with The control unit generates the drive signal so that vibration of the stylus pen due to driving of the vibration element is based on an impulse response.