JP4935781B2 - Information input device - Google Patents

Description

  The present invention relates to an information input device using capacitance.

  There are a number of touch panel methods such as a resistive film method, an electromagnetic induction method, a capacitance method, an infrared method, and an ultrasonic method. In touch panels using the capacitive method, a finger or stylus pen is brought into contact with the screen to form a capacitance (capacitor) and contact is detected by detecting the change in the weak current flowing through the capacitor. The position is detected. More specifically, a uniform electric field is applied to the entire surface of the panel, and the contact position is detected based on, for example, a very weak current (about 10 to 20 μA) that flows when the finger touches the panel.

  The advantage of the capacitive touch panel is that it is only necessary to mount one conductive thin film (conductive thin film) on the upper surface of the display device, and the structure is simpler than that of the resistive film type. In the case of the reflective type, the transmittance is high and the display quality is maintained at a high level. However, when touching the display panel, it is necessary to touch with a fingertip or a stylus pen. However, with a conventional capacitive touch panel that touches with a finger, even if an input operation is performed with the stylus pen, Since the pen tip is thin, the contact area with the display panel is reduced. For this reason, the capacity | capacitance between a nib and the transparent electrode which is an electroconductive thin film was small, and it was not able to charge detection current sufficient in order to detect a contact position.

  Here, a technique for enabling detection of a contact position using a stylus pen having a small contact area with a display panel has been proposed (for example, Patent Document 1). Specifically, for the alternating current signal supplied to the conductive layer of the capacitive touch panel, a synchronized anti-phase signal is supplied to the tip of the stylus input device, applied to the capacitor, and applied to the capacitor. There has been proposed a stylus input device that increases the contact position detection current flowing through the capacitor when the tip of the stylus input device is brought into contact with the touch panel by maximizing the amplitude of the AC signal.

JP 2007-183809 A

  However, the technique disclosed in Patent Document 1 has a configuration in which contact with a stylus pen can be detected, but contact with a finger cannot be detected. Furthermore, since it is necessary to provide a power source for driving the oscillator or the signal generator inside the stylus pen, the configuration of the stylus pen becomes complicated, and the stylus pen operability is hindered by the load due to the weight increase of the stylus pen. It is done. Further, when the current source is driven in a high frequency state, the power consumption of the touch panel drive source and the leakage current of the detection unit increase, and the mobile type device driven by a battery cannot be used for a long time.

  The present invention has been made in view of the above problems, and provides an information input device using a capacitance that can be input not only by a finger but also by a stylus pen while ensuring comfortable operability. This is the first purpose. A second object is to suppress an increase in power consumption.

  In order to solve the above-described problems, the invention described in claim 1 is directed to a stylus pen for inputting characters or a diagram, a panel portion having an insulating film and a conductive film, and the first conductive film. A signal applying unit that applies a frequency signal and the conductive film that flows due to the capacitive coupling generated in response to the capacitive coupling generated by the contact of the stylus pen or the operator's finger with the insulating film A current detection unit for detecting current; an integration unit for integrating the current detected by the current detection unit; and when the signal is applied to the conductive film by the signal application unit, the integration is performed by the integration unit. A discriminating unit that discriminates which of the stylus pen and the finger is in contact with the panel unit based on a timing at which an integrated amount of current reaches a predetermined value. It is an information input device.

  Invention of Claim 2 is the information input device of Claim 1, Comprising: The said determination part is the said integration part, when the 1st frequency signal is provided to the said electrically conductive film by the said signal provision part. It is characterized in that it is determined which of the stylus pen and the finger is in contact with the panel unit based on the time until the accumulated amount of the current accumulated by the step reaches the predetermined value.

  A third aspect of the present invention is the information input device according to the second aspect, wherein the determination unit determines that the current integrated amount in the first predetermined time is equal to or greater than the predetermined value. The panel portion is determined to be in a finger contact state where a finger is in contact, and in the finger contact state, the signal applying unit applies the first frequency signal to the conductive film, A position detection unit that detects a contact position of a finger with respect to the panel unit based on a current detected by the current detection unit is further provided.

  A fourth aspect of the present invention is the information input device according to the third aspect, wherein the determination unit is configured such that the current integrated amount in the first predetermined time is less than the predetermined value, and the first When the integrated current amount at the second predetermined time longer than the predetermined time is equal to or larger than the predetermined value, it is determined that the stylus pen is in contact with the panel unit. When the position detecting unit is in the stylus pen contact state, the signal applying unit causes the current detecting unit to apply a second frequency signal having a higher frequency than the first frequency signal to the conductive film. The contact position of the stylus pen with respect to the panel unit is detected on the basis of the current detected by.

  Invention of Claim 5 is the information input device of Claim 1, Comprising: The said determination part is the said integration part, when the 1st frequency signal is provided to the said electrically conductive film by the said signal provision part. If the first current accumulated amount of the current accumulated by the above reaches the predetermined value, it is determined that the finger is in contact with the panel unit, and the first frequency signal is detected by the signal applying unit. If the first current integration amount of the current integrated by the integration unit does not reach the predetermined value when the current is applied to the conductive film, the signal application unit has a frequency higher than that of the first frequency signal. If the second current accumulated amount of the current accumulated by the integrating unit reaches the predetermined value while the second frequency signal is applied to the conductive film, the stylus pen is in contact with the panel unit. In pen contact state Characterized by determining that that.

  A sixth aspect of the present invention is the information input device according to the fifth aspect, wherein in the case of the finger contact, a finger contact position with respect to the panel unit is detected based on the first current integrated amount. And a position detecting unit.

  A seventh aspect of the present invention is the information input device according to the fifth aspect, wherein, in the case of the pen contact, the contact position of the stylus pen with respect to the panel unit based on the second integrated current amount Is detected.

  According to the first aspect of the present invention, the contact of the finger and the contact of the stylus pen are determined based on the timing when the integrated amount of current generated when the finger or the stylus pen contacts the panel reaches a predetermined value. In addition to the touch operation with the fingertip, it is possible to input with a description with a stylus pen. Also, with such a configuration, the stylus pen configuration is not complicated, and the load due to the weight of the stylus pen is not increased, so that comfortable character input that does not hinder operability is possible.

  According to the second aspect of the present invention, based on the time until the accumulated amount of current generated when the finger or the stylus pen touches the panel reaches a predetermined value, the finger contact and the stylus pen It is possible to determine the contact, and it is possible to input not only a contact operation with a fingertip but also a description with a stylus pen.

  According to the third aspect of the present invention, the finger contact position with respect to the panel unit is detected when the integrated amount of current in the first predetermined time reaches a predetermined value. It is possible to detect the contact position.

  According to the fourth aspect of the present invention, the first frequency when the integrated amount of current in the first predetermined time does not reach the predetermined value and the integrated amount of current in the second predetermined time reaches the predetermined value. Since the second frequency signal having a higher frequency signal than the signal is applied to the panel unit to detect the contact position of the stylus pen, accurate input with the stylus pen can be performed while suppressing an increase in power consumption.

  According to the fifth aspect of the present invention, if the integrated amount of the current reaches a predetermined value when the first frequency signal is applied to the conductive film, finger contact is determined, and the first frequency signal is more than the first frequency signal. If the accumulated amount of current reaches a predetermined value when a high frequency second frequency signal is applied to the conductive film, contact with the stylus pen is determined, so that the touch operation with a fingertip is performed while suppressing an increase in power consumption. In addition, it is also possible to input with a stylus pen description.

  According to the sixth aspect of the present invention, since the finger contact position with respect to the panel unit is detected based on the first integrated current amount, the finger contact determination and the contact position detection are performed while suppressing the increase in power consumption. Can be performed simultaneously.

  According to the seventh aspect of the present invention, since the contact position of the stylus pen with respect to the panel unit is detected based on the second current integrated amount, the contact determination of the stylus pen and the contact position are suppressed while suppressing an increase in power consumption. Can be detected simultaneously.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Information input device>
FIG. 1 is a block diagram illustrating a functional configuration of an information input device 50 according to an embodiment of the invention. As shown in FIG. 1, the information input device 50 includes a main body unit 1 and a stylus pen 20, and the main body unit 1 includes a panel unit 2, an ammeter 3, an oscillator 4, an integration circuit 5, an integration amount determination unit 6, A signal output unit 7, a control unit 8, an operation unit 9, and a storage unit 10 are provided.

  The information input device 50 is configured such that the tip of the stylus pen 20 is brought into contact with the panel unit 2 adopting the electrostatic capacitance method in a form such as a user holding the stylus pen 20 in his / her hand. Characters and line diagrams are input at the contact position.

  The panel unit 2 is a part for displaying a two-dimensional image, and constitutes a screen having a rectangular outline. FIG. 2 is a diagram schematically showing a cross section of the structure of the panel unit 2 and the stylus pen 20. As shown in FIG. 2, the panel unit 2 is configured by laminating a substrate 33, a transparent conductive film 32, and an insulating layer 31 on a liquid crystal display unit (not shown). Specifically, a transparent conductive film (electrode) 32 made of a conductive material is formed on a base material 33 made of a transparent film, glass or the like, and further an insulating material is made on the transparent conductive film 32. An insulating layer 31 is stacked. The transparent conductive film 32 is made of a material that is conductive and transparent, such as indium tin oxide (ITO), and is disposed as a single electrode so as to cover the entire surface of all the pixels of the panel unit 2. ing. The transparent conductive film 32 is used to detect a contact position of the hand or the stylus pen 20, that is, an information input position. The insulating layer 31 is made of, for example, an AR coat (Anti-Reflection Coat) having an antireflection function.

  As shown in FIG. 2, the stylus pen 20 is held by the operator's hand, and the front end of the stylus pen 20 is brought into contact with the panel unit 2 to input characters and a diagram to the panel unit 2. Is. The stylus pen 20 includes a pen body portion 21, a pen tip portion 22, and a conductive portion 23 made of metal. The conductive portion 23 is provided in a grip portion gripped by an operator, and the pen tip portion 22 and the conductive portion 23 are electrically connected by a predetermined conductive member. The pen tip 22 is for making contact with the insulating layer 31 when inputting characters and diagrams, and is made of a conductive material such as aluminum, for example. The diameter of the pen tip 22 is, for example, The one with a diameter of about 3 mm is used.

  Returning to FIG. 1, the description will be continued. The ammeter 3 detects a current flowing through each reference position of the transparent conductive film 32 due to capacitive coupling generated in response to contact of the stylus pen 20 and the operator's hand with the insulating layer 31.

  The oscillator 4 applies a low frequency signal (low frequency signal) or a high frequency signal (high frequency signal) to the transparent conductive film 32 of the panel unit 2. Here, the low frequency range is, for example, 50 to 120 KHz, and the high frequency range is, for example, 1 MHz to 100 MHz.

  The integrating circuit 5 integrates the current detected by the ammeter 3.

  The integrated amount determination unit 6 determines whether or not the current amount (integrated current amount) integrated by the integration circuit 5 has reached a predetermined value (threshold value).

  The signal output unit 7 outputs a current for detecting coordinates of a contact position of the finger or the stylus pen 20 to the panel unit 2 to the control unit 8.

  The control unit 8 comprehensively controls the operation of the information input device 50. For example, the control unit 8 includes a CPU, and executes various programs and functions by executing a program stored in the storage unit 10 to be described later. Realize. For example, the control unit 8 includes a determination unit 12 and a position detection unit 13. Based on the time until the accumulated current accumulated by the integrating circuit 5 reaches a predetermined value in a state where the oscillator 4 applies the low-frequency signal to the transparent conductive film 32, the discriminating unit 12 The stylus pen 20 and the finger are in contact with each other. The position detection unit 13 detects the contact position of the finger or the stylus pen 20 with respect to the panel unit 2 based on a signal corresponding to the detection result by the ammeter 3.

  The operation unit 9 includes a keyboard, a mouse, and the like. When the user appropriately operates the operation unit 9, the operation unit 9 transmits various command signals corresponding to the operation to the control unit 8.

  The storage unit 10 is configured by a storage device such as a semiconductor memory or a hard disk, and stores a program executed by the control unit 8 and information necessary for executing the program.

<Principle of information input>
FIG. 3 is a diagram illustrating an information input mode in the panel unit 2.

  As shown in FIG. 3, in the information input device 50, by touching the panel unit 2 with the finger Fr, the dedicated stylus pen 20, or the like from the insulating layer 31 side, characters, figures, etc. are directly applied to the display image. Can be written. Here, an example in which writing is performed with the finger Fr will be described.

  4 and 5 are diagrams for explaining a method of detecting a position touched with the finger Fr, that is, an input coordinate of information. Here, a so-called capacitance method is employed. FIG. 4 shows a one-dimensional detection method of information input coordinates.

  An AC power source E1 is electrically connected to one end of the transparent conductive film 32 via a predetermined resistor Rr1, and an AC power source E2 is electrically connected to the other end of the transparent conductive film 32 via a predetermined resistor Rr2. It is connected. Each AC power source E1, E2 is grounded on the opposite side to the transparent conductive film 32.

  An AC voltage (potential e) having the same phase and the same frequency is input to the transparent conductive film 32 from both ends. At this time, if there is no touch such as the finger Fr, the potential applied from both ends is always the same, so that no current is generated in the transparent conductive film 32. However, if both ends of the surface of the screen are points A and B, so-called capacitive coupling occurs at point C when the finger Fr touches a certain position (point C).

  Here, the electrical resistance between both ends of the transparent conductive film 32 is R, the resistance from the end on the point A side of the transparent conductive film 32 to the point immediately below the point C is R1, and the end of the transparent conductive film 32 on the point B side is Assuming that the resistance immediately below the point C is R2, the following equation (1) is established.

  R = R1 + R2 (1)

  Then, due to capacitive coupling at point C, a current corresponding to the alternating voltage (potential e) applied to the transparent conductive film 32 is generated at the finger Fr. The same current as this current is also generated on the transparent conductive film 32 side. Here, since the potentials at both ends are the same at e, the amount of change in voltage from both ends of the transparent conductive film 32 to immediately below the point C has the same value. At this time, if the voltage change caused by capacitive coupling related to the finger Fr is e1, the current flowing through the resistor Rr1 is i1, and the current flowing through the resistor Rr2 is i2, the following equations (2) and (3) are established.

    e1 = i1 * R1 = i2 * R2 (2)

    R1 / R2 = i2 / i1 (3)

  Therefore, assuming that the resistance per unit length of the transparent conductive film 32 is constant, the coordinates of the position touched by the finger Fr can be detected by measuring the currents i1 and i2 flowing through the resistors Rr1 and Rr2. .

  FIG. 5 shows a method for detecting input coordinates of information for the screen of the panel unit 2. As shown in FIG. 5, AC power supplies E <b> 1 to E <b> 4 are electrically connected to four corners of the transparent conductive film 32 through predetermined resistors, respectively. The AC power supplies E <b> 1 to E <b> 4 are respectively connected to the transparent conductive film 32. The other side is grounded. At this time, when the surface of the panel unit 2 is touched with the finger Fr, by measuring the current flowing through the resistors respectively connected to the four corners of the transparent conductive film 32, the finger Fr among the surface of the panel unit 2 is measured. The coordinates of the touched position are detected. Therefore, the oscillator 4 and the ammeter 3 apply the AC voltage to the transparent conductive film 32 and measure the current to detect the input position of information.

<Finger / stylus pen contact position detection process>
In the present embodiment, when a high frequency signal is applied to the transparent conductive film 32 of the panel unit 2 in the input by the stylus pen 20 having a small contact area with respect to the panel unit 2, the impedance of the pen tip 22 of the stylus pen 20 is reduced. Since the current required for detecting the stylus pen 20 can be obtained, the contact position of the stylus pen 20 can be detected. However, if the oscillator 4 is driven in a state where the frequency is high, the power consumption of the oscillator 4 serving as the drive source of the panel unit 2 and the leakage current of the ammeter 3 increase, so that the device is a mopile type device driven by a battery. Cannot be used for a long time. On the other hand, if only the presence / absence of contact of the stylus pen 20 is discriminated, it is possible to leave the low frequency signal applied to the transparent conductive film 32. Therefore, the oscillator 4 is configured to be able to oscillate two types of frequency signals, a low frequency signal and a high frequency signal, and before applying the high frequency signal necessary for detecting the contact position of the stylus pen 20 to the transparent conductive film 32, A low frequency signal is applied to the transparent conductive film 32. Then, when a low frequency signal is applied from the oscillator 4 and the contact of the stylus pen 20 with the panel unit 2 is detected, the signal output from the oscillator 4 is switched from the low frequency signal to the high frequency signal to contact the stylus pen 20. Detect position coordinates.

  FIG. 6 is a diagram illustrating an electrical configuration according to the information input device 50. As shown in FIG. 6, the information input device 50 includes a medium 42 (finger or stylus pen 20) that contacts the panel unit 2, an ammeter 3, an oscillator 4, an integration circuit 5, an integration amount determination unit 6, and a signal output unit. 7 and electrically configured by the control unit 8.

  The oscillator 4 gives a low frequency signal or a high frequency signal to the transparent conductive film 32 of the panel unit 2 under the control of the control unit 8. 7 and 8 are diagrams showing waveforms of signals output from the oscillator 4. FIG. 7 shows the waveform of the low-frequency signal a, and FIG. 8 shows the waveform of the high-frequency signal b. 7 and 8, the horizontal axis represents the elapsed time from the signal output start time.

  Returning to FIG. 6, the description will be continued. The oscillator 4 includes a switching unit 60 that switches between a low-frequency signal a and a high-frequency signal b, and the switching unit 60 has contacts 61, 62, and 63. Under the control of the control unit 8, the switching unit 60 outputs a low frequency signal a when the contact 61 and the contact 63 are connected, and outputs a high frequency signal b when the contact 62 and the contact 63 are connected. To do.

  The ammeter 3 detects the value of current generated when the finger or the stylus pen 20 contacts the panel unit 2.

  The integrating circuit 5 integrates the current value output from the ammeter 3.

  The integrated amount determination unit 6 determines whether a value obtained by converting the current amount integrated by the integration circuit 5 into a voltage exceeds a threshold value. If the threshold value is exceeded, the control unit 8 indicates that the threshold value is exceeded. The signal is output.

  The signal output unit 7 outputs a current for detecting coordinates of a contact position of the finger or the stylus pen 20 to the panel unit 2 to the control unit 8. Based on this, the control unit 8 detects the coordinates of the contact position of the finger or the stylus pen 20.

  The control unit 8 controls the frequency of the signal output from the oscillator 4. First, the control unit 8 sets a signal output from the oscillator 4 to a low frequency signal.

  The determination unit 12 of the control unit 8 monitors changes in the amount of current detected by the ammeter 3 repeatedly in a predetermined cycle (for example, 10 μs) in order to detect any contact with the panel unit 2. Here, if the amount of current reaches a predetermined amount of current, it is determined that there is some contact.

  Moreover, the discrimination | determination part 12 of the control part 8 monitors the time when an electric current integration amount reaches a threshold value, after discriminating that there exists some contact. Here, when a signal indicating that the current amount (current integrated amount) integrated by the integrating circuit 5 has reached a predetermined value (threshold value) is input from the integrated amount determination unit 6, the current integrated amount reaches the threshold value. This time is detected to determine which of the finger and the stylus pen 20 is in contact with the panel unit 2. Specifically, if the current integrated amount in the first predetermined time (for example, 100 μs) is equal to or greater than the threshold value, it is determined that the finger is in contact with the panel unit 2 (finger contact state). . On the other hand, if the current integrated amount in the first predetermined time is less than the threshold and the current integrated amount in the second predetermined time (for example, 1 msec) longer than the first predetermined time is equal to or greater than the threshold, It is determined that the stylus pen 20 is in contact (pen contact state). As described above, it is possible to clearly and easily discriminate between the finger contact and the stylus pen contact based on the time until the integrated amount of the current generated when the finger or the stylus pen 20 contacts the panel. It becomes possible. If the integrated current amount in the second predetermined time is less than the threshold value, it is determined that neither the finger nor the stylus pen 20 is in contact with the panel unit 2.

  Next, the control unit 8 changes the frequency of the signal output from the oscillator 4 according to the determination result by the determination unit 12. Specifically, when it is determined by the determination unit 12 that the finger is in a finger contact state, a state in which a low frequency signal is applied from the oscillator 4 to the transparent conductive film 32 (low frequency signal application state) is maintained. On the other hand, when the determination unit 12 determines that the pen is in a pen contact state, the low frequency signal application state is changed to a state in which a high frequency signal is applied from the oscillator 4 to the transparent conductive film 32 (high frequency signal application state). The

  Then, when the position detection unit 13 of the control unit 8 determines that the finger contact state is present by the determination unit 12, the position detection unit 13 determines the finger based on the current input from the coordinate signal output unit 7 in the low frequency signal application state. The coordinates of the contact position are detected. Further, when it is determined by the determination unit 12 that the pen is in the pen contact state, the position detection unit 13 is based on the current input from the coordinate signal output unit 7 in the high-frequency signal application state and the stylus pen for the panel unit 2. The coordinates of the 20 contact positions are detected.

  As described above, in the control unit 8, when the panel unit 2 is touched by the finger, the frequency of the signal output from the oscillator 4 is kept low, while the panel unit 2 is touched by the stylus pen 20. If so, control is performed to increase the frequency of the signal output from the oscillator 4. By performing control according to the medium in contact with the panel unit 2 as described above, it is possible to detect the coordinates of the contact position of the finger and the stylus pen 20 while realizing power saving.

  FIG. 9 is a diagram illustrating a relationship between a signal output from the oscillator 4 and a current detected by the ammeter 3 when the finger or the stylus pen 20 contacts the panel unit 2. The horizontal axis in FIG. 9 represents the elapsed time from the start of signal output. FIG. 9A shows the waveform of a low-frequency signal output from the oscillator 4 to the transparent conductive film 32. FIG. 9 (2) shows the waveform of the current detected by the ammeter 3 when the finger touches the panel unit 2. FIG. 9 (3) shows how the current amount (current integration amount) integrated by the integration circuit 5 changes when the finger touches the panel unit 2. FIG. 9 (4) shows the waveform of the current detected by the ammeter 3 when the stylus pen 20 contacts the panel unit 2. FIG. 9 (5) is a diagram showing a change in the amount of current (current integration amount) integrated by the integration circuit 5 when the stylus pen 20 contacts the panel unit 2.

  As shown in FIGS. 9 (2) and 9 (3), when the finger touches the panel unit 2, the value obtained by converting the current accumulated amount accumulated in the first predetermined time into a voltage is a threshold value (for example, 0. 6V), the determination unit 12 determines that the finger is in contact with the panel unit 2. On the other hand, as shown in FIGS. 9 (4) and 9 (5), when the stylus pen 20 comes into contact with the panel unit 2, the integration is performed until the second predetermined time elapses after the first predetermined time elapses. Since the value obtained by converting the accumulated current amount into the voltage exceeds the threshold value, the determination unit 12 determines that the stylus pen 20 is in a pen contact state in contact with the panel unit 2.

  Thus, when the area (contact area) in contact with the panel unit 2 is large like a finger and the capacitance generated by the contact of the finger with the panel unit 2 can flow a sufficiently large current, For example, since the integrated current amount exceeds the threshold value in the first one period among the four periods of the low-frequency signal output from the oscillator 4, the contact of the finger with the panel unit 2 is detected. On the other hand, like the pen tip 22 of the stylus pen 20, the contact area that contacts the panel unit 2 is small, and a sufficiently large current generated by the contact of the stylus pen 20 with the panel unit 2 cannot flow. In this case, for example, in the third period of the low-frequency signal output from the oscillator 4, the current integrated amount exceeds the threshold value, and the contact of the stylus pen 20 is detected. In this way, in the present embodiment, it is detected which of the finger and the stylus pen 20 is in contact. In the present embodiment, the period until the touch of the panel unit 2 by the stylus pen 20 is detected is the third cycle of the low-frequency signal, but this is only an example, and is not limited thereto. .

  FIG. 10 is a diagram illustrating a state of a current detected by the ammeter 3 when performing coordinate detection of a contact position with respect to the panel unit 2 by a finger. FIG. 11 is a diagram illustrating a state of current detected by the ammeter 3 when the coordinate detection of the contact position with the panel unit 2 by the stylus pen 20 is performed. 10 and 11, the horizontal axis represents the elapsed time from the start of signal output by the oscillator 4, and the period until the second predetermined time elapses from the start of contact of the panel unit 2 with the finger or the stylus pen 20 is as follows. This is a period (contact detection period) in which it is detected whether one of the finger and the stylus pen 20 is in contact, and the coordinates at which the finger or stylus pen 20 is in contact with the panel unit 2 after the second predetermined time has elapsed. It is a period (coordinate detection period) during which is detected.

  FIG. 10 (1) shows the waveform of the low frequency signal output from the oscillator 4 to the transparent conductive film 32. FIG. 10 (2) shows a waveform of current detected by the ammeter 3 when a finger contacts the panel unit 2. FIG. 10 (3) is a diagram showing a change in the amount of current (current integration amount) integrated by the integration circuit 5 when the finger touches the panel unit 2. The waveforms up to the second predetermined time in FIGS. 10 (1) to 10 (3) are the same as the waveforms in FIGS. 9 (1) to 9 (3). As shown in FIG. 10, when it is determined that the finger has touched the panel unit 2 during the contact detection period, a low frequency signal is output from the oscillator 4 to the transparent conductive film 32 and is detected by the ammeter 3 at that time. The coordinates of the contact position by the finger are detected based on the current value.

  FIG. 11 (1) shows the waveforms of the low frequency signal and high frequency signal output from the oscillator 4 to the transparent conductive film 32. FIG. 11 (2) shows a waveform of current detected by the ammeter 3 when the stylus pen 20 contacts the panel unit 2. FIG. 11 (3) is a diagram showing a change in the amount of current (current integration amount) integrated by the integration circuit 5 when the stylus pen 20 contacts the panel unit 2. The waveforms until the second predetermined period in FIGS. 11 (1) to 11 (3) are the same as the waveforms in FIGS. 9 (1), (4), and (5). As shown in FIG. 11, when it is determined that the stylus pen 20 has touched the panel unit 2 during the contact detection period, the signal output from the oscillator 4 to the transparent conductive film 32 is switched from the low frequency signal to the high frequency signal. The coordinates of the contact position by the stylus pen 20 are detected based on the current value detected by the ammeter 3 when a high frequency signal is output from the oscillator 4 to the transparent conductive film 32. As described above, when it is determined that the contact is caused by the stylus pen 20, the frequency of the signal for coordinate detection is switched from the low frequency to the high frequency, so that the impedance related to the capacitive coupling is lowered and the current flows. The touch position by the stylus pen 20 is detected at high speed.

<Operation of information input device>
FIG. 12 is a flowchart showing an operation processing flow of the information input device 50. This operation process is controlled by the control unit 5. When the control unit 5 receives an input instruction from the operation unit 6, the process proceeds to step A1.

  In step A1, the oscillator 4 starts outputting a low frequency signal to the transparent conductive film 32. At this time, a uniform electric field is generated on the panel unit 2, and a change in the amount of current is monitored repeatedly in a predetermined cycle (for example, 10 μs) in order to detect any contact with the panel unit 2.

  In step A2, it is determined whether or not the amount of current detected by the ammeter 3 is greater than or equal to a predetermined amount. Here, if the amount of current is less than the predetermined amount, the determination in step A2 is repeated, and if the amount of current is greater than or equal to the predetermined value, it is determined that something is in contact with the panel unit 2, and the step Move to A3.

  In step A3, integration of the amount of current detected by the ammeter 3 is started by the integrating circuit 5.

  In step A4, the integrated amount of current (current integrated amount) that has been integrated in step A3 reaches the threshold value in the first predetermined time after the determination unit 12 starts integrating the current amount in step A3. It is determined whether or not it exists. Here, if the current integrated amount has reached the threshold value, it is determined that there is a finger touch, and the process proceeds to step A7. If the current integrated amount has not reached the threshold value, the process proceeds to step A5.

  In step A5, the accumulated amount of current started to be accumulated in step A3 after the first predetermined time has elapsed and the second predetermined time has elapsed since the determination unit 12 started integrating the current amount in step A3. It is determined whether or not (current integrated amount) has reached a threshold value. Here, if the current integrated amount has reached the threshold value, it is determined that there is contact by the stylus pen 20, and the process proceeds to step A6. If the current integrated amount has not reached the threshold value, the process returns to step A2.

  In Step A6, the position detection unit 13 switches the signal output from the oscillator 4 to the transparent conductive film 32 from a low frequency signal to a high frequency signal.

  In step A7, the ammeter 3 detects the current generated according to each frequency signal. That is, when it is determined that there is contact with a finger, a current generated according to the low frequency signal is detected, and when it is determined that there is contact with the stylus pen 20, it is generated according to a high frequency signal. A current is detected.

  In step A8, the position detection unit 13 detects the coordinates of the contact position of the finger or the stylus pen 20 from the current value detected in step A7, and the operation flow ends.

  According to the present invention, the contact of the finger and the contact of the stylus pen 20 are discriminated based on the time until the integrated amount of the current generated when the finger or the stylus pen 20 contacts the panel unit 2 reaches a predetermined value. The For this reason, not only the touch operation by the fingertip but also the input by the description with the stylus pen 20 held on the finger is possible. Also, with such a configuration, the configuration of the stylus pen 20 is not complicated, and the load due to the weight of the stylus pen 20 is not increased, so that comfortable character input that does not hinder operability is possible. Further, when the integrated amount of current in the first predetermined time reaches a threshold value, the contact position of the finger with respect to the panel unit 2 is detected, and the integrated amount of current after the first predetermined time elapses until the second predetermined time. When the value reaches a predetermined value, a second frequency signal having a frequency higher than that of the first frequency signal is applied to the panel unit 2, and the contact position of the stylus pen 20 is detected. For this reason, accurate input with a finger or the stylus pen 20 is possible while suppressing an increase in power consumption.

  That is, in the present embodiment, the frequency of the signal is kept low in the case of contact with a finger, and the frequency of the signal is increased in the case of contact with the stylus pen 20, thereby realizing power saving and achieving stylus pen 20. It is possible to detect the contact position corresponding to both inputs by the fingertip.

<Modification>
As mentioned above, although embodiment of this invention was described, this invention is not limited to the thing of the content demonstrated above.

  For example, in the above embodiment, the stylus pen 20 and the finger are applied to the panel unit 2 based on the time until the accumulated amount of current when the low frequency signal is applied to the transparent conductive film 32 reaches the threshold value. However, if the integrated amount of the current when the low frequency signal is applied to the transparent conductive film 32 reaches the threshold value, it is determined that the finger is in a contact state. If the integrated amount does not reach the threshold value, a high frequency signal is applied to the transparent conductive film 32, and if the integrated current amount reaches the threshold value, the stylus pen 20 is in contact with the panel unit 2. You may discriminate | determine that it is in a state. That is, it is determined which of the stylus pen 20 and the finger is in contact with the panel unit 2 based on the timing of applying the low frequency signal or the high frequency signal until the accumulated amount of current reaches the threshold value. May be. Further, the coordinates of the contact position of the finger or the stylus pen 20 are detected based on the integrated amount of current when the threshold is reached so that the detection of the contact medium with respect to the panel unit 2 and the coordinate detection of the contact position can be performed simultaneously. Also good. Here, the integrated amount of current used for detecting the coordinates of the contact position of the stylus pen 20 is either an integrated amount of current based only on the high frequency signal or an integrated amount of current based on the low frequency signal and the high frequency signal. But you can.

  In the above embodiment, in order to detect the contact position by the stylus pen 20, the frequency of the signal applied from the oscillator 4 to the transparent conductive film 32 is increased, but the amplitude of the signal is increased to increase the stylus. You may detect the contact position with the pen 20. FIG.

It is a block diagram which illustrates the functional composition of the information input device concerning the embodiment of the present invention. It is a figure which shows typically the cross section of the structure of a panel part and a stylus pen. It is a figure which illustrates the input mode of the information in a panel part. It is a figure for demonstrating the detection method of the position touched with the finger | toe, ie, the input coordinate of information. It is a figure for demonstrating the detection method of the position touched with the finger | toe, ie, the input coordinate of information. It is a figure which shows the electrical constitution of an information input device. It is a figure which shows the waveform of the signal output from an oscillator. It is a figure which shows the waveform of the signal output from an oscillator. It is a figure which shows the relationship between the output signal from an oscillator, and the electric current detected with an ammeter at the time of the contact with respect to the panel part of a finger | toe or a stylus pen. It is a figure which shows the state of the electric current detected with an ammeter when performing the coordinate detection of the contact position of a finger | toe. It is a figure which shows the state of the electric current detected with an ammeter when performing the coordinate detection of the contact position of a stylus pen. It is a flowchart which shows the operation processing flow of an information input device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main-body part 2 Panel part 3 Ammeter 4 Oscillator 5 Integrating circuit 12 Discriminating part 13 Position detection part 20 Stylus pen 32 Transparent conductive film 50 Information input device

Claims (7)

A stylus pen for entering text or line diagrams,
A panel portion having an insulating film and a conductive film;
A signal applying unit that applies a first frequency signal to the conductive film;
A current detection unit for detecting a current flowing in the conductive film due to capacitive coupling generated in response to capacitive coupling generated by contact of the stylus pen or an operator's finger with the insulating film;
An integration unit for integrating the current detected by the current detection unit;
When the signal is applied to the conductive film by the signal applying unit, the stylus pen and the panel unit are connected to the panel unit based on the timing at which the integrated amount of the current integrated by the integrating unit reaches a predetermined value. A discriminator for discriminating which of the fingers is in contact;
An information input device comprising: The information input device according to claim 1,
Based on the time until the integrated amount of the current integrated by the integrating unit reaches the predetermined value when the determining unit is applying the first frequency signal to the conductive film by the signal applying unit, An information input device that determines which of the stylus pen and the finger is in contact with the panel unit. The information input device according to claim 2,
The determining unit determines that the finger is in contact with the panel unit in response to the integrated amount in the first predetermined time being equal to or greater than the predetermined value;
In the finger contact state, the signal applying unit applies the first frequency signal to the conductive film, and based on the current detected by the current detecting unit, the finger contact position with respect to the panel unit is determined. Position detection unit to detect,
An information input device further comprising: The information input device according to claim 3,
The determination unit is configured such that the integrated amount at the first predetermined time is less than the predetermined value, and the integrated amount at a second predetermined time longer than the first predetermined time is equal to or greater than the predetermined value. Accordingly, it is determined that the stylus pen is in contact with the stylus pen with respect to the panel unit,
When the position detecting unit is in the stylus pen contact state, the signal applying unit applies a second frequency signal having a frequency higher than the first frequency signal to the conductive film, and the current detecting unit An information input device that detects a contact position of the stylus pen with respect to the panel unit based on a detected current. The information input device according to claim 1,
If the determination unit reaches the predetermined value when the first integrated amount of the current integrated by the integration unit when the first frequency signal is applied to the conductive film by the signal applying unit, the panel unit It is determined that the finger is in contact with the finger, and the first integration of the current integrated by the integration unit when the signal applying unit applies the first frequency signal to the conductive film. If the amount does not reach the predetermined value, a second frequency signal accumulated by the integrating unit is applied to the conductive film while a second frequency signal having a frequency higher than the first frequency signal is applied to the conductive film by the signal applying unit. When the integrated amount reaches the predetermined value, the information input device determines that the stylus pen is in contact with the panel unit and is in a pen contact state. The information input device according to claim 5,
In the case of the finger contact, a position detection unit that detects a finger contact position with respect to the panel unit based on the first integrated amount;
An information input device further comprising: The information input device according to claim 5,
A position detecting unit that detects a contact position of the stylus pen with respect to the panel unit based on the second integrated amount when the pen is in contact;
An information input device further comprising:

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