Contact detection device, notification device, contact detection program, and notification program

Abstract

To reduce a false detection and a detection omission that are caused by a change in an environment in which a touch sensor is utilized.SOLUTION: A reference value A of a touch sensor is not set as a fixed value, but a measured value P that changes in accordance with a change in a utilization environment, such as a temperature or a humidity, is periodically measured, and the reference value A is set and updated by utilizing the measured value P. Hence, a threshold B (=A+threshold C) for determining whether a touch is made or not becomes a value in accordance with the utilization environment. Since measured values P3 and P4 measured in an environment E1 are equal to or greater than the threshold B (E2), a determination is made that a touch is made for both measured values (see FIG. 1). Conversely, in another environment E2, the reference value A (E2) and the threshold B (E2) are updated in accordance with the environment E2. Hence, even if the measured values P3 and P4 are the same as those in the environment E1, a determination is made that a touch is made for the measured value P3 since the measured value P3 is equal to or greater than the threshold B (E2), but a determination is made that a contact is not made for the measured value P4 since the measured value P4 is smaller than the threshold B (E2). In this manner, a false detection and a detection omission can be avoided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a contact detection device, a notification device, a contact detection program, and a notification program, and relates to detection by a capacitance type touch sensor. [Background technology]

[0002] Various devices such as contact detection devices using capacitance-type touch sensors are widely used as devices for detecting the presence or absence of specific operations, or for detecting data input or screen operations (for example, Patent Document 1). A capacitive touch sensor measures the capacitance when a person touches the sensor, and detects contact if the capacitance increases by more than a threshold amount C compared to when the sensor is not being touched.

[0003] FIG. 8 shows the principle of contact detection using a conventional capacitive touch sensor. 8, in a conventional capacitance-type touch sensor (hereinafter simply referred to as a touch sensor), a capacitance value (hereinafter simply referred to as a non-contact capacitance value) measured in a standard environment E0 (e.g., temperature 23°C, humidity 50%) without a person touching the touch sensor is used as a reference value A0. A threshold value B0 is set by adding a threshold amount C to this reference value A0, and when a capacitance equal to or greater than the threshold value B0 is detected, it is determined that a user has touched the touch sensor. For example, as shown on the left side of FIG. 8, if the detected capacitance P is P1 that is equal to or greater than a threshold value B0, it is determined that there is contact, and if it is less than the threshold value B0, it is determined that there is no contact.

[0004] The conventional reference value A0, threshold amount C, and threshold value B0 are all fixed values. Therefore, as shown on the right side of Figure 8, if the capacitance values ​​measured in a different measurement environment E1 are the same values ​​P3 and P4, it is determined that the user has touched the touch sensor because they exceed the threshold value B0 (fixed value) determined based on the fixed reference value A0.

[0005] However, the non-contact capacitance value of a touch sensor changes depending on the measurement environment, such as temperature and humidity. That is, as shown on the right side of Figure 8, the non-contact capacitance value measured in environment E1, which is different from the standard environment E0, fluctuates to a value A' higher than the fixed reference value A0. Also, similar to the change from the reference value A0 to A', the geodetic values ​​that would be P1 and P2 in the standard environment E0 change to P3 and P2 in the environment E1. In this case, the capacitance measurement value P3 measured in the measurement environment E1 exceeds both the fixed threshold value B0 and the threshold value B' obtained by adding the threshold amount C to the non-contact capacitance value A', so there is no problem in detecting contact. However, in the case of capacitance measurement value P4, the increase from non-contact capacitance value A' is not greater than threshold amount C (= threshold value B' or greater), so although the measurement value should actually be judged as non-contact, it is mistakenly judged as contact because it is greater than threshold value B0. Conversely, when the non-contact electrostatic quantity value A' is lower than the reference value A0, the measured value P, which should actually be judged as contact, may be below the threshold value B0 and may be judged as non-contact. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-18669 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to reduce false detections and missed detections that occur due to changes in the environment in which a touch sensor is used. [Means for solving the problem]

[0008] (1) In the invention described in claim 1, a capacitance type touch sensor and a contact detection means for detecting a touch when a capacitance measurement value of the touch sensor exceeds a threshold value B are provided. a measurement trial means for performing a measurement trial at every predetermined time T; a capacitance acquisition means for acquiring a measurement value P of capacitance of the touch sensor; In the measurement trial, Using the obtained measurement value P The reference value A of the touch sensor is updated, and the updated reference value A is added to the threshold amount C, which is a fixed value. and an updating means for updating the threshold value B. The capacitance acquisition means acquires a measurement value P n times in the measurement trial, and the update means acquires an average value of the acquired n measurement values ​​P in the measurement trial as a measurement trial value S, and updates the reference value A using the acquired measurement trial value S. The present invention provides a contact detection device characterized by the above features. ( 2 )Claims 2 In the invention described in the item (1), the updating means updates the reference value A to a moving average value of m trial measurement values ​​S obtained in m trial measurements. 1 The present invention provides a contact detection device according to the present invention. ( 3 )Claims 3 In the invention described in the item (1), the present invention further comprises a clearing means for clearing the measurement trial value S acquired before the current measurement trial and the reference value A immediately before the current measurement trial when the acquired measurement trial value S is smaller than the reference value A before updating by at least a lower limit L1, and the updating means updates the reference value A using the measurement trial value S acquired after the measurement trial cleared by the clearing means. 1 or claims 2 The present invention provides a contact detection device according to the present invention. ( 4 )Claims 4 and a discarding means for discarding the measurement trial value S acquired in the current measurement trial if the acquired measurement trial value S is greater than the reference value A before updating by an upper limit or more, and the updating means updates the reference value A by using the reference value A immediately before the current measurement trial in place of the discarded measurement trial value S. 1 , claim 2 or claims 3 The present invention provides a contact detection device according to the present invention. ( 5 )Claims 5 In the invention described in claim 1 to claim 2, 4a push button disposed below the touch sensor of the contact detection device; a push detection means for detecting the push of the push button; and an abnormal condition reporting means for reporting an abnormal condition to a predetermined reporting destination when a touch on the touch sensor is detected and a push of the push button is detected. ( 6 )Claims 6 In the invention described in the above, a touch detection function is provided which detects that a touch has been made when the capacitance measured by the capacitance type touch sensor exceeds a threshold value B; A measurement trial function that performs a measurement trial at every predetermined time T, and in the measurement trial, a capacitance acquisition function for acquiring a measurement value P of capacitance of the touch sensor; In the measurement trial, Using the obtained measurement value P The reference value A of the touch sensor is updated, and the updated reference value A is added to the threshold amount C, which is a fixed value. an update function for updating the threshold value B; and a contact detection program for realizing the above in a computer. the capacitance acquisition function acquires a measurement value P n times in the measurement trial, and the update function acquires an average value of the acquired n measurement values ​​P as a measurement trial value S in the measurement trial, and updates a reference value A using the acquired measurement trial value S. to provide. ( 7 )Claims 7 In the invention described in claim 6 Contact detection program according to claim 1 Each function in a press detection function that detects pressing of a push button disposed below the touch sensor, and an abnormal condition reporting function that reports an abnormal condition to a predetermined reporting destination when the contact detection function detects that the touch sensor has been touched and also detects pressing of the push button. To realize it on a computer Provide a reporting program. [Effects of the Invention]

[0009] In the present invention, the threshold value B is updated using the measured capacitance value P of the touch sensor, so that it is possible to reduce false detections and missed detections that occur due to changes in the environment in which the touch sensor is used. [Brief explanation of the drawings]

[0010] [Figure 1] 10 shows the state of the reference value A that is set and updated depending on the measurement environment and the principle of contact detection by the touch sensor of this embodiment. [Figure 2] FIG. 1 is an external configuration diagram of a notification device equipped with a touch sensor. [Figure 3] FIG. 2 is a functional configuration diagram of the notification device for reporting an abnormality. [Figure 4] FIG. 2 is an explanatory diagram illustrating a hardware configuration of a notification device. [Figure 5] 10 is an explanatory diagram of a threshold amount C, an upper limit value, an upper limit L2, a lower limit value, and a lower limit L1. [Figure 6] 10 is a flowchart showing the contents of a reference value process for determining a reference value A by the reporting device. [Figure 7] FIG. 10 is an explanatory diagram conceptually showing the contents and timing of a measurement trial. [Figure 8] 1 is an explanatory diagram showing the principle of contact detection by a conventional capacitive touch sensor; DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the contact detection device, the notification device, the contact detection program, and the notification program of the present invention will be described in detail below with reference to FIGS. (1) Overview of the embodiment In the touch sensor of this embodiment, the reference value A is not a fixed value, but the capacitance value (measured value P), which changes in response to changes in the usage environment such as temperature and humidity, is measured periodically to set and update the reference value A. As a result, the threshold value B (= A + threshold value C) for determining whether or not a touch has occurred also becomes a value that corresponds to the usage environment. In this embodiment, in order to be able to set and update the reference value A appropriately even when the power is turned on while the user is touching the touch sensor or when the user continues to touch the touch sensor after the power is turned on, the reference value A is determined based on the measured capacitance value (including the case of a non-contact capacitance value) without being limited to a non-contact state. However, in the following explanation of the principle (FIG. 1), in order to simplify the explanation, the case where the measured capacitance value is a non-contact electrostatic quantity value will be explained as an example.

[0012] FIG. 1 shows the state of the reference value A that is set and updated depending on the measurement environment and the principle of contact detection by the touch sensor of this embodiment. 1, in the touch sensor of this embodiment, the capacitance value of the touch sensor measured periodically is used to set and update the reference value A according to the changing measurement environment, such as reference value A(E1) in measurement environment E1, reference value A(E2) in measurement environment E2, etc. That is, as shown in FIG. 1, when the touch sensor moves from environment E1 to environment E2, the reference value A(E1) is changed to reference value A(E2), as indicated by arrow q1. Then, thresholds B(E1) and B(E2) for both environments are determined by adding a fixed threshold amount C (details of which will be described later in FIG. 5) to the reference values ​​A(E1) and A(E2) set according to the environment. That is, as shown by arrow p2 in FIG. 1, the value of threshold B is changed from threshold B(E1) obtained by adding threshold amount C to reference value A(E1) for environment E1 to threshold B(E2) obtained by adding threshold amount C to reference value A(E2) for environment E2 as shown by arrow q2 in FIG. 1. In this way, by using a reference value A and threshold value B according to the environment, if the capacitance measured increases by more than the threshold amount C from the reference value A (= A(E1), A(E2)) in the measurement environment (exceeds threshold value B), it can be determined that there is contact, making it possible to avoid false detections and missed detections.

[0013] Now, as shown in Figure 1, suppose that touch sensor measurement values ​​P3 and P4 are obtained in environment E1, and then when the touch sensor is moved to environment E2 and measured again, measurement values ​​P5 and P6 are obtained, and that the measurement values ​​in both environments E1 and E2 are the same, i.e., P5 = P3 and P6 = P4. If the reference value A and threshold value B in environment E2 remain the same as those in environment E1 (E1) and (E1) despite changes in the measurement environment, the measurement value P6 (=P4), which should actually be judged as non-contact, will be judged as contact. In contrast to this, in this embodiment, in response to a change in the measurement environment from environment E1 to environment E2, reference value A is changed from A(E1) to A(E2), and threshold value B is changed from B(E1) to B(E2). As a result, a correct determination is made in both cases: measurement value P5 (=P3) measured in environment E2 is equal to or greater than threshold value B(E2), indicating contact, and measurement value P6 (=P4) is less than threshold value B(E2), indicating non-contact.

[0014] The reference value A is determined as follows. That is, when a terminal equipped with a touch sensor is started up (powered on), the capacitance measurement value P (including non-contact capacitance values) of the touch sensor is measured n consecutive times (e.g., n = 3 times) every time a predetermined time T (e.g., T = 20 seconds) has elapsed, and the average value of the n measurements (= (ΣP) / n) is calculated. In this embodiment, the above process is called a "measurement trial", and the measurement trial is performed within a predetermined time (for example, several milliseconds). The average value of n measurement trials obtained in this measurement trial is called a "measurement trial value S".

[0015] In order to smooth out fluctuations in the trial measurement value S due to environmental changes in temperature and humidity, the moving average of m (e.g., three) trial measurement values ​​is calculated and used as the reference value A for the current (current) trial measurement. Here, the moving average of the trial measurement values ​​is the average (=(ΣS) / m) of the trial measurement values ​​S for m periods going back from the current trial measurement. In this manner, in this embodiment, the reference value A is calculated and updated using the trial measurement value S calculated every predetermined time T. Then, a determination is made as to whether or not a contact has occurred for the measurement value P for determining contact of the touch sensor based on a reference value A (and threshold value B) determined using a measurement trial value S obtained at least within a time T+α (α = time of measurement trial) going back from the time of the measurement. Therefore, by using threshold value B (= reference value A + threshold amount C) that is updated according to the ambient environment (temperature, humidity) of the touch sensor, it is possible to avoid false detection or missed detection of touch for the measurement value P of the touch sensor.

[0016] In addition, in the embodiment, a situation where the power of the notification device 1 is turned on while the user is touching the touch sensor 22 of the notification device 1, or a situation where metal is in contact with the touch sensor 22, is defined as a "special state," and processing for the special state is specified. That is, if the measurement trial value S is equal to or less than (reference value A - lower limit L1), the current reference value A before updating, the moving average buffer, etc. are cleared, and the touch sensor function is temporarily disabled until m measurement trial values ​​S, including the current measurement trial, are obtained again. The disabled touch sensor function is released when the cleared reference value A is newly set. On the other hand, if the measurement trial value S is equal to or greater than (reference value A + upper limit L2), the measurement trial value S for that measurement is discarded, and the current reference value A is used instead of the discarded measurement trial value S to calculate the moving average value, which becomes the new reference value A.

[0017] (2) Details of the embodiment FIG. 2 shows the external configuration of a notification device 1 equipped with a touch sensor to which this embodiment is applied. The notification device 1 is a device for reporting an abnormal condition to a predetermined notification center (emergency center, etc.) when a user senses an emergency or abnormality. For this reason, the notification device 1 is formed in a small, portable size so that the user can wear it at all times or carry it in a bag, etc., and has a strap hole (not shown) formed on the top.

[0018] The front of the reporting device 1 is provided with a reporting button 21, a touch sensor 22, a display panel 23, a microphone 24, and a speaker 25. These will be described in detail later. The report button 21 is a mechanical button that detects when it is physically pressed, and a capacitance type touch sensor 21 is disposed on the top of the report button 21. By arranging the touch sensor 21 on the top of the notification button 21 in this manner, the notification device 1 is configured to detect contact (touch) by the touch sensor 21 and to issue a notification to the notification center when it detects that the notification button 21 has been pressed. Although not shown, the notification device 1 also includes a power button, a battery, a USB terminal, a charging terminal for charging the battery, an antenna for communication, and the like.

[0019] As shown in the figure, the display panel 23 displays various information such as the radio wave reception status, remaining battery power, etc., the communication status such as "reporting" in relation to an abnormality notification, and other instructions for the user. In this embodiment, the touch sensor 22 applied to the reporting device 1 is disposed above the reporting button 21, and the display panel 23 is disposed in a position separate from the touch sensor. In contrast, when the touch sensor 22 is applied as a data input unit of a normal terminal device or the like, the touch sensor 22 described in this embodiment is disposed above the display panel 23.

[0020] The microphone 24 is an input device for transmitting the user's voice to the reporting center when reporting an abnormality. On the other hand, the speaker 25 is an output device that outputs the operator's voice or electronic voice received from the reporting center when an abnormality is reported.

[0021] FIG. 3 shows the functional configuration of the abnormality reporting function of the reporting device 1. As shown in FIG. 3, the notification device 1 functions as a reference value processing unit 10a, a reference value A storage unit 10b, a touch detection unit 10c, a notification unit 10d, and other units by the control unit 10 performing various processes using a notification program 271 and a reference value program 272, which will be described later. The control unit 10 receives a button signal B from the notification button 21 and a measurement value P from the touch sensor 22 . The reference value processing unit 10a of the control unit 10 obtains a trial measurement value S from a trial measurement performed at every predetermined time T, and obtains a reference value A from the moving average value of the obtained trial measurement value S. The reference value processing unit 10a stores the obtained reference value A in the reference value A storage unit 10b (setting after the power button is turned on and updating thereafter). Furthermore, the reference value processing unit 10a supplies a sensor function disable signal and a sensor function enable signal to the reporting unit 10d. That is, the reference value processing unit 10a supplies a sensor function disable signal when the measurement trial value S is equal to or smaller than the lower limit L1, and supplies a sensor function enable signal when the measurement trial value S is greater than the lower limit L1 and less than the upper limit L2.

[0022] The touch detection unit 10c determines whether or not the user has touched the touch sensor, separately from the detection of the touch sensor 22 performed in the measurement trial. That is, like a conventional touch sensor, the touch detection unit 10c detects the user's touch if the measured capacitance value P of the touch sensor 22 is greater than the threshold value B. Here, threshold value B is a value obtained by adding threshold amount C to reference value A, but because reference value A of touch sensor 22 is updated as needed by reference value processing unit 10a, threshold value B is also updated to an appropriate value depending on the environment in which it is used, such as humidity and temperature. Therefore, unlike conventional methods that use fixed values, in this embodiment, contact detection is performed more accurately in accordance with the usage environment.

[0023] When the touch sensor function is enabled, the reporting unit 10d reports the occurrence of an abnormal state to the reporting center on the condition that it detects both a contact at the touch detection unit 10c and an input of button signal B (report button on) from the report button 21. When this report is made, "Reporting" is displayed on the display panel 23 as shown in FIG. Furthermore, when the touch sensor function is enabled, if the touch detection unit 10c detects contact but does not input the report button signal B, it can be determined that the user's finger or the like has simply touched the touch sensor 22, and the reporting unit 10d does not report an abnormality. Conversely, if the report button signal B is input but the touch detection unit 10c does not detect contact, it can be determined that the button was not pressed by the user but was simply pressed by an object such as a key, and the reporting unit does not report an abnormality. On the other hand, when the touch sensor function is disabled, the notification unit 10d determines that the touch sensor 22 is in a special state, and notifies the notification center of an abnormality simply by inputting the button signal B from the notification button 21, regardless of whether or not the touch detection unit 10c detects contact.

[0024] Fig. 4 shows the hardware configuration of the reporting device 1. The same components in Fig. 4 as those shown in Fig. 2 and Fig. 3 are denoted by the same reference numerals, and their description will be omitted where appropriate. As shown in Fig. 4, the reporting device 1 includes a control unit 10, a reporting button 21, a touch sensor 22, a display panel 23, a microphone 24, a speaker 25, a communication control unit 26, and a storage unit 27. The control unit 1 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 performs various information processing and control operations in accordance with programs stored in various storage units such as the ROM 12 and the storage unit 27. Specifically, the CPU 11 executes a reporting program 271 and a reference value program 272, which will be described later, to determine whether the user has touched the reporting button 21 and to report to a reporting center.

[0025] The RAM 13 is a working memory that temporarily stores programs and data required when the CPU 11 performs various calculations and controls. In this embodiment, the RAM 13 temporarily stores initial value data 130, a reference value area 131, a number of measurement attempts 132, a sensor function flag 133, a measurement value buffer 134, a moving average buffer 135, and measurement values ​​136. The initial value data 130 is data that is initially set when the power is turned on, and specifically, the threshold amount C, upper limit L2, and lower limit L1 (details will be described later) read from the storage unit 27 are stored.

[0026] The reference value area 131 to the moving average buffer 135 in the RAM 13 are data that are saved and used in the reference value processing performed by the reference value program 272 . The reference value area 131 is an area reserved for storing the reference value A that is set and updated depending on the environment in which the touch sensor 22 is used. This reference value area 131 corresponds to the reference value A storage unit 10b in the functional configuration of the abnormality reporting function of the reporting device 1 (FIG. 3). The number of measurement attempts 132 stores the number of measurement attempts, and is counted up to a maximum of m times each time a measurement attempt is performed. The sensor function flag 133 is a flag that is turned on during the period from when the power is turned on until the (m-1)th measurement attempt, and when a special state occurs in which the measurement attempt value S is equal to or less than (reference value A-lower limit L1) (S20; Y described below). When this sensor function flag 133 is on, the touch sensor function is disabled, and when determining whether or not to report the user's abnormal state to the reporting center, an abnormality is reported simply by pressing the report button 21.

[0027] The measurement value buffer 134 is an area in which n measurement values ​​P of the touch sensor 22 measured in a measurement trial are stored. In this embodiment, the number of times that the measurement value P is measured for each measurement trial is n=3, and the measurement value buffer 134 stores the measurement values ​​P for three times.

[0028] The moving average buffer 135 stores the average value (= trial measurement value S) of the n number of measurement values ​​P stored in the measurement value buffer 134 . This moving average buffer 135 stores m measurement trial values ​​S in the order in which the measurement trials were performed. For the (m+1)th measurement trial and thereafter, the oldest measurement trial value S in the moving average buffer 135 is rewritten with the latest measurement trial value S. Note that a memory with a FIFO (first-in, first-out) function may be used as the moving average buffer 135.

[0029] The measurement value 136 stores the capacitance (measurement value P) of the touch sensor 22 measured at predetermined intervals, separate from the measurement trials for obtaining the reference value A. Whether or not there has been contact by the user is determined based on whether or not this measurement value P exceeds the threshold value B (=reference value A+threshold amount C). In this embodiment, the determination result regarding the contact is used to determine whether or not to report an abnormality.

[0030] The communication control unit 26 is connected to a notification center via a communication network such as the Internet, for example, to notify the user that an abnormal condition has occurred, and to transmit and receive voice and information between the notification device 1 and the notification center.

[0031] The storage unit 27 is configured by various storage means such as a large-capacity hard disk or semiconductor memory such as flash memory, or by a combination of these storage means. The storage unit 27 stores a reporting program 271, a reference value program 272, initial value data 273, and other programs and data. The reporting program 271 is a program for executing the abnormality reporting function described with reference to FIG. The reference value program 272 is a program that uses the measurement value P of the touch sensor 22 to set and update the reference value A according to the environment (humidity, temperature, etc.) in which the touch sensor 22 is used.

[0032] The initial value data 273 stores the threshold amount C2, the upper limit L2, and the lower limit L1 that are initially set in the initial value data 130 of the RAM 13. FIG. 5 is an explanatory diagram of the threshold amount C, the upper limit value, the upper limit L2, the lower limit value, and the lower limit L1. FIG. 5 shows the values ​​measured by the touch sensor 22 and the actual capacitance values ​​(pF) corresponding to those values, and shows 14000 (3.5 pF) as an example of the reference value A0 (reference value A in the standard environment E0). The increase or decrease values ​​based on each value of this reference value A0 are expressed as ± values. However, each capacitance value varies depending on the area of ​​the electrodes of the touch sensor (panel), the distance between the electrodes, the material of the panel, etc. Figure 5 shows the values ​​for a specific product as an example. In FIG. 5, the reference value A0=14000 (3.5 pF) is used as the reference, and an increase from the reference value A0 is represented by a plus (+) and a decrease by a minus (-). As a specific example, the threshold amount C is +400 (+0.1 pF), the upper limit L2 is +200 (+0.05 pF), and the lower limit L1 is +300 (+0.7 pF). The threshold amount C, the upper limit L2, and the lower limit L1 will be explained below.

[0033] The threshold amount C is a value used to calculate the threshold B by adding it to the reference value A obtained using the capacitance value P of the touch sensor 22, which is measured periodically, and is the increase in the capacitance value from the reference value A to the threshold value B. When a person touches the non-contact touch sensor 22, the capacitance value increases, but the amount of increase does not change with changes in the environment, so the threshold amount C is a fixed value and is determined from the amount of increase relative to the reference value A0 in the standard environment E0. As an example, as shown on the right side of Figure 5, when an adult firmly touches the touch sensor with the pad of their finger, the capacitance value increases (+) by approximately 1200 (0.3 pF) from the reference value A0, while in the case of a child, it increases (+) by approximately 500 (0.125 pF). Therefore, the increase amount Δ (the increase amount from the reference value A0) is determined using samples of capacitance values ​​when users of various ages and genders actually touch the touch sensor 22, and a value smaller than this increase amount Δ is set as the threshold amount C. Since contact cannot be detected unless reference value A + increase amount Δ > threshold B (= reference value A + threshold amount C), threshold amount C must be less than increase amount Δ. For example, threshold amount C is selected in the range of 30% to 80% of increase amount Δ. The threshold value B is a threshold value for determining whether the touch sensor 22 has been touched, and it is determined that the touch sensor 22 has been touched when the capacitance value (measured value P) detected by the touch sensor 22 is equal to or greater than the threshold value B. Since the threshold amount C is a fixed value, the threshold B, like the reference value A, varies depending on the environment in which the touch sensor 22 is used, making it possible to make an appropriate contact determination depending on the environment.

[0034] The upper limit L2 and the lower limit L1 are limit values ​​used in the reference value processing to determine whether the touch sensor 22 is in a special state. That is, if the trial measurement value S is equal to or greater than the upper limit value (= reference value A + upper limit limit L2) (hereinafter referred to as the upper limit special state), or if the trial measurement value S is equal to or less than the lower limit value (= reference value A - lower limit limit L1) (hereinafter referred to as the lower limit special state), it is determined to be a special state. As mentioned above, the trial measurement value S is the average value ((ΣP) / n) of n measurement values ​​P in the trial measurement.

[0035] The upper limit special state is a special state that occurs when, for example, metal or the like comes into contact with the touch sensor 22. In order to make it possible to determine whether or not an upper limit special state exists, the upper limit L2 is set to a value smaller than the threshold amount C and smaller than the increase of +300 (+0.075 pF) when metal is in contact, which is approximately w times the threshold amount C (in this embodiment, w = 0.5 C), or in this embodiment, the upper limit L2 = +200 (+0.05 pF). As a result, as shown by the black circle in Figure 5, when the measurement trial value S is a measurement trial value S12 that is equal to or greater than the upper limit value (A+L2) of 1600 (3.55 pF), which is the sum of the upper limit L2 and the reference value A, it is determined to be an upper limit special state. If it is determined to be an upper limit special state that is equal to or greater than the upper limit value (A+L2), as in the case of measurement trial value S12, the current measurement trial value S is discarded, and the current reference value A is saved in moving average buffer 135 (see step 23 in Figure 6). On the other hand, as indicated by the double circle, when the trial measurement value S11 is less than the upper limit, it is determined to be in a normal state, and the touch sensor function is enabled (see step 24 in FIG. 6).

[0036] On the other hand, the lower limit special state is a special state that occurs when the reference value A becomes high, for example, when the power is turned on while the user is touching the touch sensor 22, or when the user is continuously touching the touch sensor 22. In this case, the lower limit special state is also an abnormality in the reference value A that has increased due to continuous contact. In this special state in which the reference value A has increased, the trial measurement value S will fall below the lower limit value (A0-L1) in the trial measurement immediately after the contact with the touch sensor 22 is released. The lower limit L1 is selected, for example, within a range of a decrease of −200 (−0.05 pF) to −400 (0.1 pF) from the reference value A0 (see FIG. 8) when measured in a standard environment E0. In this embodiment, the lower limit L1 is set to −300 (0.075 pF). As a result, as shown by the black circle in Figure 5, when the measurement trial value S is a measurement trial value S14 that is less than the lower limit value obtained by adding the lower limit L1 to the reference value A0, that is, a lower limit special state = 1100 (3.425 pF), it is determined to be in a lower limit special state. If it is determined to be in a lower limit special state, such as measurement trial value S14, that is less than the lower limit value (A-L1), the reference value A and all values ​​in the moving average buffer 135 are cleared, the touch sensor function is disabled, and the initial state is restored (see steps 21 and 15 in Figure 6). On the other hand, as indicated by the double circle, when the trial measurement value S13 is greater than the lower limit, it is determined to be in a normal state (step 20 in FIG. 6; Y). In Figure 5, the reference value A0 in the standard environment E0 is displayed as 1400 (3.5 pF), and each value is expressed as an increase or decrease relative to this value. However, except when determining the threshold amount C, in the actual touch sensor contact detection and reference value processing (Figure 6) that changes the reference value A, the threshold, upper limit value, and lower limit value that are increased or decreased relative to the reference value A that is updated according to the measurement environment are used.

[0037] Next, the operation of the reference value processing performed by the reporting device 1 configured as above will be described. 6 is a flowchart showing the contents of the reference value processing for determining the reference value A, which is processed by the CPU 11 of the notification device 1 executing the reference value program 272. This reference value program 272 is executed every predetermined time T seconds (periodically) after the power of the notification device 1 is turned on. In this embodiment, the process is executed every T seconds = 20 seconds, but it may be executed at other time intervals, for example, every 10 seconds, every 30 seconds, every 60 seconds, etc. However, if the time T is long, a time lag occurs in updating the reference value A, so it is preferable to set the time T to a maximum of 120 seconds or less, and preferably 60 seconds or less. In addition, when the remaining charge of the battery for driving the notification device 1 falls below a predetermined amount (for example, 10% of the total), the value of T seconds may be changed to a longer value depending on the remaining battery charge, such as changing T seconds to a time longer than the default value of 20 seconds, for example, 60 seconds.

[0038] The CPU 11 determines whether the report button 21 is being pressed (step 11), and if it is being pressed (step 11; Y), ends the current reference value processing. If the notification button 21 is not being pressed (step 11; N), the CPU 11 determines whether or not a specific display based on the abnormality notification (for example, the display of "Notifying" shown in Figure 2) is being displayed on the display panel (step 12), and if it is being displayed (step 12; Y), the current reference value processing is terminated.

[0039] If the display panel is not displaying a specific value (step 12; N), the CPU 11 acquires the trial measurement value S (step 13). Figure 7 shows a conceptual representation of the content and timing of the measurement trials. As shown in the lower part of FIG. 7, a measurement trial is performed every time the reference value process of the reference value program 272 is performed (=every T seconds). In each measurement trial, the CPU 11 measures the capacitance value of the touch sensor 22 n times within a few milliseconds from the start of the measurement trial, as shown in the upper part of FIG. 7, and stores the measurement values ​​P1 to Pn in the measurement value buffer 134 in the order of measurement. The CPU 11 calculates the average value (ΣP) / n of the stored measurement values ​​P1 to Pn, and acquires it as the trial measurement value S. This trial measurement value S becomes the object to be stored in the moving average buffer 135.

[0040] 6, after acquiring the measurement trial value S in step 13, the CPU 11 determines whether m measurement trials have been completed (step 14). That is, the CPU 11 determines whether the value of the measurement trial count 132 in the RAM 13 is m. If the value of the number of measurement attempts 132 is less than m and m measurement attempts have not been completed (step 14; N), the CPU 11 disables the touch sensor function of the touch sensor 22 by turning off the sensor function flag 133 in the RAM 13 (step 15). This excludes contact with the touch sensor 22 from the criteria for reporting an abnormality.

[0041] Next, the CPU 11 stores the trial measurement value S acquired in step 13 in the moving average buffer 135 of the RAM 13, and clears the measurement value buffer 134 in which n measurement values ​​P are stored (step 16). The CPU 11 also adds 1 to the value of the number of measurement trials 132 in the RAM 13 (step 17), and checks whether the number of measurement trials after the addition has reached m (step 18). If the number of measurements has not reached m (step 18; N), the CPU 11 terminates the current reference value processing because the number of trial measurement values ​​S required to obtain the reference value A has not been stored in the moving average buffer 135 after the power was turned on. The above processing from step 14;Y to step 18 is repeated from measurement trial 1 immediately after power-on to the m-th measurement trial m, as shown in the lower part of FIG.

[0042] On the other hand, if the number of measurements is m, i.e., if this measurement attempt is the mth (step 18; Y), the CPU 11 calculates the moving average value = ΣS / m of the m measurement attempt values ​​S1 to Sm stored in the moving average buffer 135, sets the calculated reference value A in the reference value area 131 of the RAM 13 (step 19), and terminates this reference value processing.

[0043] Returning to step 14, if the mth measurement attempt has been completed, i.e., if the value of the measurement value buffer 134 is m times (step 14; Y), the CPU 11 performs processing when the touch sensor 22 is in a special state (lower limit special state, upper limit special state) and updates the reference value A. That is, the CPU 11 reads the reference value A and the lower limit L1 from the reference value area 131 and the initial value data 130, and determines whether the measurement trial value S obtained in step 13 is less than or equal to (reference value A - lower limit L1) (step 20).

[0044] If the measurement trial value S is less than or equal to (A-L1) (step 20; Y), for example, in the case of the measurement trial value S14 shown in Figure 5, the CPU 11 clears the reference value A in the reference value area 131, all data in the moving average buffer 135, and the number of measurement trials 132 (step 21), and proceeds to step 15. As a result, in this measurement trial, the processing from step 15 onwards described above will be repeated m times, just like the measurement trial immediately after power-on.

[0045] In step 20, the trial measurement value S≦(A−L1) occurs when the user releases contact with the touch sensor 22 after the reference value A has risen due to continuous contact with the touch sensor 22 for a predetermined period of time. In this case, the trial measurement value acquired in step 13 is the value in the state where the user has released contact with the touch sensor 22. Therefore, in step 21, the moving average buffer 135 is cleared, and after step 15, the CPU 11 stores the trial measurement value S obtained in step 13 of the current trial measurement in the moving average buffer 135 (step 16). The CPU 11 may also discard (clear) the trial measurement value S acquired in the current trial measurement, disable the touch sensor function (step 15), and then terminate the process. In this case, the trial measurement value S from the next trial measurement is saved in the moving average buffer 135.

[0046] On the other hand, if the measured trial value S is greater than (A-L1) (step 20; N), for example, in the case of the trial measurement value S13 shown in Figure 5, the CPU 11 determines whether the measured trial value S is greater than or equal to (reference value A+upper limit L2) (step 22). If the measurement trial value S is greater than or equal to (A+L2) (step 22; Y), for example, in the case of the trial measurement value S12 shown in Figure 5, it is determined that the upper limit special state has occurred due to metal or the like coming into contact with the touch sensor 22, so the CPU 11 discards the measurement trial value S obtained in step 13, saves the current reference value A stored in the reference value area 131 in the moving average buffer 135 (step 23), and proceeds to step 26. The reference value A to be saved in place of the discarded measurement trial value S is saved by overwriting the oldest value among the m measurement trial values ​​S saved in the moving average buffer 135 (the measurement trial value S saved in the measurement trial m times before the current measurement trial).

[0047] If the trial measurement value S is smaller than (A+L2) (step 22; N), for example, in the case of the trial measurement value S11 shown in Fig. 5, that is, since it is not a special state (lower limit special state, upper limit special state), the CPU 11 turns on the sensor function flag 133 in the RAM 13 to enable the touch sensor function of the touch sensor 22 (step 24). As a result, it becomes necessary to satisfy both the conditions of contact with the touch sensor 22 and pressing of the report button 21 as the judgment conditions for reporting an abnormality.

[0048] Thereafter, the CPU 11 stores the trial measurement value S obtained in step 13 in the moving average buffer 135 (step 25). The trial measurement value S obtained in the current trial measurement is saved by overwriting the oldest trial measurement value S, in the same way as when the reference value A is saved in step 23 .

[0049] Next, the CPU 11 calculates the moving average value (ΣS) / m using the m measurement trial values ​​S stored in the moving average buffer 135, and updates the reference value A in the reference value area 131 using the calculated moving average value as the new reference value A (step 26), thereby ending this measurement trial.

[0050] As described above, according to the notification device 1 of this embodiment that employs the touch sensor 22, the capacitance of the touch sensor 22 is measured periodically, and the reference value A is set and updated according to the measured capacitance value (measurement value P), so that a more appropriate reference value A can be used in accordance with changes in the environment (temperature, humidity) in which the touch sensor 22 is used. In this way, instead of using a fixed value for the reference value A, an appropriate reference value A is used according to the usage environment of the touch sensor 22, and the threshold value B is set to the value obtained by adding the threshold amount C (fixed value) to this changing reference value A. Therefore, even if the usage environment of the touch sensor 22 changes, there are fewer false detections or missed detections of touch, and it is possible to more accurately determine whether or not a touch has occurred.

[0051] Furthermore, rather than using the measurement trial value S obtained in one measurement trial as the reference value A, for each measurement trial, the moving average ΣS / m of the measurement trial values ​​S going back m times from the most recent measurement trial value S is used as the reference value A. By taking the moving average in this way, the fluctuations in the measurement trial value S are smoothed, preventing extreme fluctuations in the reference value A, and making it possible to use a reference value A that takes into account not only the environment after the change but also the environment during the change. However, in this embodiment, m=3, but by setting m=1 and using the measurement trial value S obtained for each measurement trial as the reference value A, it is possible to obtain a reference value A that responds promptly to the changed environment. It is also possible to set m to another number of times, such as 2 times or 4 times, and furthermore, the user may be able to change the value of the number of times m depending on the situation in which it is used.

[0052] Furthermore, in each measurement trial, the measurement value P of the touch sensor 22 is not measured only once, but is measured n times, and the average value = ΣP / n is taken as the measurement trial value S. This reduces the influence of measurement errors of the capacitance by the touch sensor 22. The number of times that the measurement value P is measured in each measurement trial is n=3, but it can also be reduced to one or two, or increased to four or five, etc., and the measurement value P for the specified number of measurements can be stored in the measurement value buffer 134. However, while it is possible to set both the number of measurements (n times) of the measurement value P to obtain the measurement trial value S and the number of measurement trials (m times) to obtain the reference value A to one, it is preferable to set either one (n or m) to multiple times.

[0053] In addition, in the embodiment, by setting an upper limit (reference value A + upper limit L2) and a lower limit (reference value A - lower limit L1) of the measurement trial value S obtained in the measurement trial, it is possible to eliminate missed or false alarms and reliably process abnormality notifications even in situations such as when metal is in contact with the touch sensor 22 or when the user is holding the notification device 1.

[0054] The above describes one embodiment of the notification device 1 that uses the touch sensor 22, but the present invention is not limited to the described embodiment, and various modifications can be made within the scope described in each claim. For example, in the embodiment described above, the notification device 1 is described as using the touch sensor 22. However, the touch sensor 22 may be disposed on the screen of a display device, and may be applied to a touch panel that detects a touch and the touch position, thereby detecting an input to the display content displayed corresponding to the detected touch position. Also, a touch panel using the touch sensor 22 can be used in a terminal device such as a mobile terminal. In this case, unlike the reporting device 1 of the embodiment described above, the reporting button 21 is not required. Also, in the reference value processing described in the flowchart of Fig. 6, steps 11, 12, 15, and 24, which are processing for the reporting device 1, are not required.

[0055] Furthermore, when the touch sensor 22 is applied to the reporting device 1 described above and the mobile terminal described in the above variant, it is also possible to omit the processing corresponding to the special state of the touch sensor 22 and adopt a processing for setting and updating the reference value A using the measurement trial value S obtained in the measurement trial. In this case, steps 20, 21, 22, and 23 are omitted from the flowchart of FIG.

[0056] In the embodiment described above, the capacitance (measured value P) of the touch sensor 22, which changes depending on the state (environment) in which it is used, is measured periodically, and the reference value A is calculated using the measured value P. Alternatively, other methods may be adopted, as long as they use a measurement value P measured periodically and change the threshold value B for determining whether the user is in contact or not depending on the usage environment. For example, the conventional reference value A0 (fixed value) described in FIG. 8 may be used, and the threshold value B' may be found by finding the trial measurement value S and the amount of variation Δ from the reference value A0. That is, the amount of change ΔC (=threshold amount C+Δ) of the threshold amount C may be calculated from the amount of change Δ thus obtained. In this case, the threshold B′ is B′=A0+ΔC. Alternatively, the calculated amount of change Δ may be used directly to calculate the post-change threshold value B=A0+Δ+C.

[0057] In addition, in the embodiment described above, when the measurement trial value S is equal to or greater than the upper limit value (= reference value A + upper limit limit L2), it is compared with the lower limit value (= reference value A - lower limit limit L1) and determined that the touch sensor 22 is in a special state (upper limit special state, lower limit special state). In contrast to this, instead of the trial measurement value S, it may be compared with each of the measurement values ​​P (P1 to Pn) measured in the trial measurement. In this case, if any one of the measured values ​​P is equal to or greater than the upper limit value and equal to or less than the lower limit value, it is determined to be in a special state.

[0058] In the embodiment described above, the reference value A is the moving average value of m trial measurement values ​​S obtained by periodically performing trial measurements. Alternatively, the value of the weighted moving average K of m trial measurement values ​​S may be used as the reference value A. Here, the trial measurement values ​​S to be added are S1, S2, ..., Sm in order of oldest to newest, and the addition range of Σ is s=1 to s=m, then the weighted average K is K=(Σ((Ss)×s)) / Σs.

[0059] In the embodiment described below, the reference value A determined according to the environment is stored in the reference value area 131 of the RAM 13. Therefore, when the power of the reporting device 1 or the terminal device described in the above modification is turned off, the reference value A stored in the reference value area 131 is cleared, and when the power is turned on thereafter, the reference value A will not be determined until m measurement attempts are completed. Therefore, when the power is turned off, the reference value A stored in the reference value area 131 may be stored in the storage unit 27 before the power is turned off. In this case, the reference value A stored in the storage unit 27 is stored in the reference value area 131 when the power is turned on again, in the same way that the initial value data 273 is stored in the initial value data 130 of the RAM 13. In this way, by storing the reference value A in the memory unit 27 when the power is turned off, when the power is turned on thereafter, the reference value A and the threshold value B can be immediately used to determine whether or not the user has touched the touch sensor 22. [Explanation of symbols]

[0060] 1 Notification device 10 Control Unit 10a Reference value processing section 10b Storage section 10c Touch detection unit 10d Reporting Department 21 Touch Sensor 21 Report button 23 Display panel 24. Mike 25 speakers 26 Communication control section 27 Memory section 130 Initial Value Data 131 Reference Value Area 132 measurement attempts 133 Sensor Feature Flags 134 Measurement Buffer 135 Moving Average Buffer 136 measurements 271 Reporting Program 272 Reference Value Program 273 Initial Value Data A Standard Value B. Threshold C. Threshold amount L1 Lower limit L2 upper limit P measurement value S Trial measurement value T predetermined time

Claims

1. A capacitive touch sensor, a touch detection means for detecting a touch when a capacitance measurement value by the touch sensor exceeds a threshold value B; a measurement trial means for performing a measurement trial at every predetermined time T; a capacitance acquisition means for acquiring a measurement value P of the capacitance of the touch sensor in the measurement trial; and an updating means for updating a reference value A of the touch sensor using the acquired measurement value P in the measurement trial, and updating the threshold value B with a value obtained by adding a threshold amount C, which is a fixed value, to the updated reference value A; the capacitance acquisition means acquires a measurement value P n times in the measurement trial, the updating means acquires an average value of the n acquired measurement values ​​P as a measurement trial value S in the measurement trial, and updates the reference value A using the acquired measurement trial value S; A contact detection device characterized by:

2. the updating means updates the reference value A to a moving average value of m trial measurement values ​​S obtained in m trial measurements; 2. The contact detection device according to claim 1.

3. a clearing means for clearing the measurement trial value S acquired before the current measurement trial and the reference value A immediately before the current measurement trial when the acquired measurement trial value S is smaller than the reference value A before the update by at least a lower limit L1; the updating means updates the reference value A using the trial measurement value S obtained after the trial measurement cleared by the clearing means; 3. The contact detection device according to claim 1 or 2.

4. a discarding means for discarding the measurement trial value S acquired in the current measurement trial when the acquired measurement trial value S is greater than the reference value A before updating by an upper limit or more; the updating means updates the reference value A by using the reference value A immediately before the current measurement trial in place of the discarded measurement trial value S; 4. The contact detection device according to claim 1, claim 2, or claim 3.

5. A contact detection device according to any one of claims 1 to 4; a push button disposed below the touch sensor of the contact detection device; a push detection means for detecting the push of the push button; an abnormality notification means for notifying a predetermined notification destination of an abnormality when it is detected that the touch sensor has been touched and that the push button has been pressed; A notification device comprising:

6. a touch detection function that detects a touch when a capacitance measurement value of a capacitance type touch sensor exceeds a threshold B; a measurement trial function for performing a measurement trial every predetermined time T; a capacitance acquisition function for acquiring a measurement value P of the capacitance of the touch sensor in the measurement trial; an updating function that updates a reference value A of the touch sensor using the acquired measurement value P in the measurement trial, and updates the threshold value B with a value obtained by adding a threshold amount C, which is a fixed value, to the updated reference value A; A contact detection program for realizing the above in a computer, The capacitance acquisition function acquires a measurement value P n times in the measurement trial, The updating function acquires an average value of the n acquired measurement values ​​P as a measurement trial value S in the measurement trial, and updates the reference value A using the acquired measurement trial value S. A contact detection program comprising:

7. Each function of the contact detection program according to claim 6; a press detection function for detecting a press of a push button disposed below the touch sensor; an abnormality state reporting function that reports an abnormality state to a predetermined reporting destination when the contact detection function detects that the touch sensor has been touched and that the push button has been pressed; A reporting program to realize this on a computer.

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