JP2005174190A - Electronic pen position detection circuit, device, and system, and circuit element mounting method for electronic pen position detection circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly make an infrared signal propagate to an infrared ray receiving section. <P>SOLUTION: An electronic pen position detection circuit finds each period of time from receiving the infrared signal transmitted by an infrared signal transmission section to receiving an ultrasonic signal transmitted by an ultrasonic signal transmission section at a plurality of parts in order to detect a position of the electronic pen which has the ultrasonic signal transmission section and the infrared signal transmission section and detects the position of the electronic pen based on each period of time concerned. While mounting a plurality of ultrasonic signal receiving sections which receive the ultrasonic signal on one mounting surface of a circuit board, the infrared signal receiving section which receives the infrared signal is mounted on the other mounting surface at opposite side of the above mounting surface of the circuit board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic pen position detection circuit, an electronic pen position detection device, an electronic pen position detection system, and a circuit element mounting method for an electronic pen position detection circuit.

  As one of digitizer systems, a system (hereinafter referred to as the following) is used to detect characters and pictures written with an electronic pen on a paper medium or the like by using ultrasonic signals and infrared signals, and to transmit them to a personal computer or the like. An electronic pen position detection system) has been developed. In addition, such an electronic pen position detection system is mainly configured by an electronic pen and an electronic pen position detection device (for example, refer to Patent Document 1 shown below).

  The electronic pen is an input device in which an ultrasonic transmission unit and an infrared transmission unit are stored in a storage container having a pen shape. When writing characters or pictures on a paper medium, the electronic pen operates while the tip of the electronic pen is in contact with the paper medium. Then, an infrared signal is transmitted from the infrared transmission unit, and an ultrasonic signal is transmitted from the ultrasonic transmission unit to the electronic pen position detection device. Here, the infrared signal propagates to the electronic pen position detection device at the speed of light, whereas the ultrasonic signal propagates to the electronic pen position detection device at a speed of sound slower than the speed of light. There is a deviation in the propagation time between the two.

The electronic pen position detection device detects the current position of the electronic pen using the deviation of the propagation time. More specifically, in the electronic pen position detection device, a circuit board (electronic pen position detection circuit) on which two or more ultrasonic wave reception units and an infrared reception unit are mounted is stored in a storage container. Then, each time from when the infrared signal transmitted from the infrared transmitter is received to when the ultrasonic signal transmitted from the ultrasonic transmitter is received by each ultrasonic receiver is obtained. By each time, the distance from the electronic pen to each ultrasonic wave reception unit is known, and using this distance information, the intersection obtained by the principle of trigonometry is detected as the current position of the electronic pen.
JP 2003-36225 A

  FIG. 14 shows a front view of an electronic pen position detection circuit housed in the electronic pen position detection device. The electronic pen position detection circuit simply mounts the ultrasonic receivers 210a and 210b on the left and right corners of the mounting surface of the circuit board 250, respectively, and further receives infrared rays near the middle of the ultrasonic receivers 210a and 210b. Part 220 can be implemented. According to this mounting method, the ultrasonic receiving units 210 a and 210 b and the infrared receiving unit 220 are mounted on the same mounting surface of the circuit board 250.

  Here, in general, the ultrasonic receivers 210 a and 210 b have a taller physical structure than the infrared receiver 220. For this reason, as shown in FIG. 15, when the electronic pen 100, the ultrasonic receiver 210a (or the ultrasonic receiver 210b), and the infrared receiver 220 are positioned on a straight line, for example, The infrared receiver 220 becomes a blind spot of the ultrasonic receiver 210a (or the ultrasonic receiver 210b), and the infrared signal transmitted from the infrared transmitter of the electronic pen 100 propagates to the infrared receiver 220 in the worst case. The problem of not doing will arise.

  The present invention has been made in view of the above-described problems, and an electronic pen position detection circuit, an electronic pen position detection device, an electronic pen position detection system, and an electronic pen position detection in which an infrared signal is reliably transmitted to an infrared receiver. An object of the present invention is to provide a circuit element mounting method for a circuit.

  The main aspect of the present invention for solving the above-described problem is that an infrared signal transmitted from the infrared signal transmission unit is received to detect the position of the electronic pen having the ultrasonic signal transmission unit and the infrared signal transmission unit. An electronic pen position detection circuit that obtains each time until the ultrasonic signal transmitted from the ultrasonic signal transmission unit is received at a plurality of locations and detects the position of the electronic pen based on the time. And mounting a plurality of ultrasonic signal receivers for receiving the ultrasonic signals on one mounting surface of the circuit board, and on the other mounting surface opposite to the one mounting surface of the circuit board. In addition, an infrared signal receiving unit that receives the infrared signal is mounted.

  According to the present invention, when the electronic pen, the ultrasonic receiving unit, and the infrared receiving unit are, for example, in a straight line, the mounting surface of the infrared receiving unit and the ultrasonic receiving unit Since the mounting surfaces are different, the infrared receiving unit does not have to be a blind spot of the ultrasonic receiving unit. Therefore, the infrared signal transmitted from the infrared transmission unit of the electronic pen is reliably transmitted to the infrared reception unit.

  According to the present invention, there are provided an electronic pen position detection circuit, an electronic pen position detection device, an electronic pen position detection system, and a circuit element mounting method for an electronic pen position detection circuit in which an infrared signal is reliably propagated to an infrared receiver. Can do.

<Overall configuration of electronic pen position detection system>
FIG. 1 is a diagram showing an overall configuration of an electronic pen position detection system according to the present invention.
The electronic pen position detection system detects characters and pictures written on the medium 300 by the electronic pen 100 by using an infrared signal and an ultrasonic signal generated by the electronic pen 100, and detects the detected information. This is a system for displaying on a display device 400 provided in a personal computer or the like.
In addition, the electronic pen position detection system does not require special paper or a special board specialized for this system, and the size of the large sized plate-like body such as a whiteboard or the size of the JIS standard that is more compact than the plate-like body. Any medium 300 distributed in the market such as a paper medium having (A4 size, B5 size, etc.) can be used.

<Configuration of electronic pen and electronic pen position detection device>
FIG. 2 is a block diagram illustrating the configuration of the electronic pen 100 and the electronic pen position detection device 200.

=== Configuration of the electronic pen ===
The electronic pen 100 is an input device in which an infrared transmission unit 110, an ultrasonic transmission unit 120, a switch 130, a control circuit 140, and a power source 150 are stored in a storage container having a pen shape.

  The infrared transmitter 110 is activated when the tip of the electronic pen 100 contacts the medium 300 and the switch 130 is turned on. An infrared signal (about 30 THz to 300 THz) having the speed of light is generated by applying a voltage to the infrared light emitting diode, and is transmitted to the infrared receiving unit 220 of the electronic pen position detecting device 200. The generation and transmission of the infrared signal is continuously performed at a predetermined cycle until the switch 130 is turned off.

  The ultrasonic transmitter 120 is activated when the tip of the electronic pen 100 comes into contact with the medium 300 and the switch 130 is turned on. Then, when a voltage is applied to the piezoelectric element type ultrasonic oscillator, an ultrasonic signal (about 20 KHz to 100 MHz) having a sound speed slower than the speed of light is generated, and the electronic pen position detecting device 200 receives infrared rays. Propagated to unit 220. The generation and transmission of the ultrasonic signal are continuously performed at the same predetermined cycle as that of the infrared signal until the switch 130 is turned off.

  The switch 130 detects that the tip of the electronic pen 100 is in contact with the medium 300 when a character or a picture is written on the medium 300 by the electronic pen 100 by detecting a pressure change at the time of the contact. To do. At this time, the switch 130 is turned on, and the infrared transmission unit 110 and the ultrasonic transmission unit 120 are activated.

  On the other hand, when characters and pictures have been written on the medium 300 and the tip of the electronic pen 100 is not in contact with the medium 300, the switch 130 is turned off, and the infrared transmission unit 110 and the ultrasonic transmission unit The operation of 120 stops.

  The control circuit 140 is a circuit that controls the entire electronic pen 100, and may be a microcomputer, for example. The power source is a device that supplies power to each component of the electronic pen 100, and for example, a battery can be adopted.

=== Configuration of Electronic Pen Position Detection Device ===
The electronic pen position detection device 200 is an infrared and ultrasonic receiver device in which an ultrasonic receiving unit 210, an infrared receiving unit 220, a control circuit 230, and a communication interface circuit 240 are stored in a storage container 500.

  The ultrasonic reception unit 210 is an ultrasonic sensor using PVDF (Polyvinyl Den Fluoride) or the like, and receives an ultrasonic signal transmitted from the ultrasonic transmission unit 120 of the electronic pen 100. It is necessary to provide at least two ultrasonic receiving units 210 for detecting the position of the electronic pen 100 by the triangulation method, but in the following, two ultrasonic receiving units 210a and 210b are provided. The case will be described.

  The infrared receiver 220 is an infrared sensor such as an IrDA (Infrared Data Association) standard module, and receives an infrared signal transmitted from the infrared transmitter 110 of the electronic pen. Note that the infrared receiving unit 220 generally has a short physical structure as compared to the ultrasonic transmission unit 210.

  The control circuit 230 is a circuit that controls the entire electronic pen position detection device 200, and may be a microcomputer, for example. Further, the control circuit 230 detects the current position of the electronic pen 100 on the medium 300 based on the ultrasonic signals received by the ultrasonic receiving units 210a and 210b and the infrared signal received by the infrared receiving unit 220. To do. As a result, the electronic pen position detection apparatus 200 can identify information on characters and pictures written on the medium 300 by the electronic pen 100.

  The communication interface circuit 240 is a communication interface for transmitting character and picture information written on the medium 300 with the electronic pen 100 to a mobile electronic device such as a personal computer or a mobile phone. As such a communication interface, for example, a serial communication method such as USB (Universal Serial Bus) standard or IEEE 1394 standard, or a wireless communication method such as infrared communication or Bluetooth (registered trademark) can be adopted.

=== Method for detecting the position of the electronic pen ===
FIG. 3 is a diagram illustrating transmission / reception timings of infrared signals and ultrasonic signals exchanged between the electronic pen 100 and the electronic pen position detection device 200.

  First, on the electronic pen 100 side, when the tip of the electronic pen 100 and the medium 300 come into contact with each other, the switch 130 is turned on, an IR (Infrared Ray) pattern (infrared signal) is generated in the infrared transmission unit 110, and the infrared reception unit 220 (see FIG. 3: time t0). This IR pattern is used for the purpose of synchronizing the reception of the PVDF pattern (ultrasound signal) transmitted from the ultrasound transmitter 120 with the ultrasound receivers 210a and 210b.

  Similarly, when the switch 130 is turned on, a PVDF pattern is also simultaneously generated in the ultrasonic transmission unit 120. However, when the PVDF pattern is generated, the high voltage applied to the ultrasonic transmission unit 120 is generated slightly later than the IR pattern by the time required to generate a high voltage by a predetermined booster (not shown) ( FIG. 3: Refer to time t1). This PVDF pattern is used for detecting the position of the electronic pen 100 on the medium 300.

  On the other hand, on the electronic pen position detection apparatus 200 side, since the IR pattern that is an infrared signal has a higher propagation speed than the PVDF pattern that is an ultrasonic signal, the PVDF pattern is received by the ultrasonic receivers 210a and 210b. Prior to being performed, the IR pattern is received by the infrared receiver 220 (see FIG. 3: time t3).

  Thereafter, the PVDF patterns transmitted from the ultrasonic transmission unit 120 are received by the ultrasonic reception units 210a and 210b, respectively (see FIG. 3: times t5 and t6). Here, the electronic pen position detection device 200 has a time from when the IR pattern is received by the infrared receiving unit 220 to when the PVDF pattern is received by the ultrasonic receiving units 210a and 210b (FIG. 3: tL, tR). Each). As a result, the distance between the electronic pen 100 and the ultrasonic receivers 210a and 210b is obtained based on the propagation speed of the PVDF pattern.

  Even if the distance between the electronic pen 100 and the ultrasonic receivers 210a and 210b is obtained, if the orientation of the electronic pen 100 with respect to the reference line between the ultrasonic receivers 210a and 210b is not obtained, The position of the electronic pen 100 cannot be grasped. Therefore, as shown in FIG. 4, the electronic pen position detection device 200 uses the distance from the electronic pen 100 to each of the ultrasonic wave receivers 210a and 210b (see FIG. 4: L1 and L2) on the principle of trigonometry. The obtained intersection is detected as the current position of the electronic pen.

<Appearance structure of electronic pen position detection circuit>
FIG. 5 is a front view of an electronic pen position detection circuit housed in the electronic pen position detection device 200, and FIG. 6 is a plan view of the electronic pen position detection circuit.

  As shown in FIGS. 5 and 6, the electronic pen position detection circuit is superposed on the two corners on the operation area 310 side of the medium 300 to be operated by the electronic pen 100 on one mounting surface of the circuit board 250. The sound wave receiving units 210a and 210b are mounted. In this way, by mounting the ultrasonic receiving units 210a and 210b toward the left and right corners of the one mounting surface described above, the superposition of the left corner and the right corner of the one mounting surface described above is extremely high. The operation area 310 can be expanded in the width direction of the medium 300 as compared with the case where the sound wave receiving units 210a and 210b are mounted.

  Further, the infrared receiving unit 220 is mounted around the center of the side on the operation area 310 side (see FIG. 6) on the other mounting surface opposite to the one mounting surface described above. This is because the infrared receiving unit 220 is mounted near the center between the ultrasonic receiving unit 210a and the ultrasonic receiving unit 210b in order to be used for the purpose of synchronizing the reception of ultrasonic signals in the ultrasonic receiving units 210a and 210b. It is because it is preferable to do.

  Note that the infrared receiving unit 220 has a side on the operation area 310 side (see FIG. 6) on the mounting surface of the infrared receiving unit 220 so that angle directivity that can correspond to a wider range of operation area 310 on the medium 300 is obtained. It is preferable that the mounting is performed by shifting the position in the direction opposite to the operation area 310 side (see FIG. 6) from the part. For example, as shown in FIG. 6, when the electronic pen position detection circuit is viewed from directly above, the mounting position is such that only the hemispherical infrared light receiving unit included in the infrared receiving unit 220 is visible.

  Also, in order to ensure the angle directivity of the infrared receiving unit 220, the ultrasonic receiving units 210a and 210b are mounted with a position shifted in the direction toward the operation area 310 (see FIG. 6) compared to the infrared receiving unit 220. Is preferred. That is, the infrared receiver 220 is substantially in the direction opposite to the operation area 310 side (see FIG. 6) from the center of the side on the operation area 310 side (see FIG. 6) on the mounting surface of the infrared receiver 220. The position is shifted to be mounted. Therefore, protrusions 260a and 260b extending from two corners on the operation area 310 side (see FIG. 6) on the mounting surfaces of the ultrasonic receiving portions 210a and 210b are provided. Then, as shown in FIG. 7, the ultrasonic receiving units 210a and 210b are mounted on the protrusions 260a and 260b.

<Appearance structure of electronic pen position detector>
FIG. 8 is a front view of the electronic pen position detection device 200, and FIG. 9 is a plan view of the electronic pen position detection device 200. The electronic pen position detection device 200 is a unit in which the electronic pen position detection circuit described with reference to FIGS.

  Here, the storage container 500 has an infrared signal on the surface on the operation area 310 (see FIG. 6) side of the medium 300 to be operated by the electronic pen 100 among the surfaces surrounding the mounting surface of the infrared receiving unit 220. An IR filter 510 for passing the light is disposed. As a result, noise signals other than infrared wavelengths cannot be received in the infrared receiving unit 220, and the S / N ratio of the infrared receiving unit 220 is improved.

  In addition, the storage container 500 has a slit-shaped opening 520 for taking an ultrasonic signal into the storage container 500 on the surface on the operation area 310 side among the surfaces surrounding the mounting surfaces of the ultrasonic receiving units 210a and 210b. Is arranged. When the electronic pen position detection circuit is completely shielded so as not to be seen from the outside, since the ultrasonic signal is a sound wave, the ultrasonic signal is not propagated to the ultrasonic receiving units 210a and 210b. For this reason, the opening 520 must be provided.

<Infrared signal is propagated>
FIG. 10 is a diagram of a state when the infrared signal is received by the electronic pen position detection device 200 as viewed from directly above, and FIG. 11 is a diagram of the state as viewed from the front right oblique direction. .

  As shown in FIGS. 10 and 11, the case where the electronic pen 100, the ultrasonic receiving unit 210a (or the ultrasonic receiving unit 210b), and the infrared receiving unit 220 are in a relationship of being positioned on a straight line, for example. Think. In this case, since the mounting surface of the infrared receiving unit 220 is different from the mounting surface of the ultrasonic receiving unit 210a (or ultrasonic receiving unit 210b), the infrared receiving unit 220 may be replaced with the ultrasonic receiving unit 210a (or ultrasonic receiving unit). 210b) does not have to be a blind spot. Therefore, the infrared signal transmitted from the infrared transmission unit 220 of the electronic pen 100 is reliably propagated to the infrared reception unit 220 inside the electronic pen position detection device 200 via the IR filter 510.

<Other embodiments>
Although the present embodiment has been described above, the above-described examples are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed / improved without departing from the spirit thereof, and the present invention can also include equivalents thereof.

  For example, in the electronic pen position detection circuit shown in FIGS. 5 to 7, the ultrasonic receiving units 210a and 210b are provided on the upper side of the circuit board 250, and the infrared receiving unit 220 is provided on the lower side of the circuit board 250. 12 and 13, as shown in FIGS. 12 and 13, the infrared receiving unit 220 is provided on the upper side of the circuit board 250, and the ultrasonic receiving units 210a and 210b are provided on the lower side of the circuit board. You may make it mount. Even with this mounting method, the same effects as those of the above-described embodiment can be obtained.

It is a figure showing the whole electronic pen position detection system composition concerning one embodiment of the present invention. It is a block diagram which shows the structure of the electronic pen position detection system which concerns on one Embodiment of this invention. It is a figure explaining the transmission / reception timing of the infrared signal and ultrasonic signal which are exchanged between the electronic pen which concerns on one Embodiment of this invention, and an electronic pen position detection apparatus. It is a figure explaining the position detection method of the electronic pen which concerns on embodiment of this invention. It is a front view of the electronic pen position detection circuit which concerns on one Embodiment of this invention. It is a top view of the electronic pen position detection circuit which concerns on one Embodiment of this invention. It is a top view of the electronic pen position detection circuit which concerns on other embodiment of this invention. It is a front view of the electronic pen position detection apparatus which concerns on one Embodiment of this invention. It is a top view of the electronic pen position detection apparatus which concerns on one Embodiment of this invention. It is the figure which looked at the mode at the time of receiving an infrared signal in the electronic pen position detection apparatus concerning one embodiment of the present invention from right above. It is the figure which looked at the mode at the time of receiving an infrared signal in the electronic pen position detection apparatus concerning one embodiment of the present invention from the front right diagonal direction. It is a front view of the electronic pen position detection circuit which concerns on other embodiment of this invention. It is a top view of the electronic pen position detection circuit which concerns on other embodiment of this invention. It is a front view of the conventional electronic pen position detection circuit. It is the figure which looked at the mode at the time of receiving an infrared signal in the conventional electronic pen position detection circuit from right above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electronic pen 110 Infrared transmission part 120 Ultrasonic transmission part 130 Switch 140 Control circuit 150 Power supply 200 Electronic pen position detection apparatus 210 Ultrasonic reception part 220 Infrared reception part 230 Control circuit 240 Communication interface circuit 250 Circuit board 260 Protrusion part 300 Medium 400 Display device 500 Storage container 510 IR filter 520 Opening

Claims (6)

The ultrasonic signal transmitted from the ultrasonic signal transmitter from when the infrared signal transmitted from the infrared signal transmitter is received to detect the position of the electronic pen having the ultrasonic signal transmitter and the infrared signal transmitter. Is an electronic pen position detection circuit that obtains each time until it is received at a plurality of locations and detects the position of the electronic pen based on each time,
While mounting a plurality of ultrasonic signal receivers for receiving the ultrasonic signal on one mounting surface of the circuit board,
Mounting an infrared signal receiving unit for receiving the infrared signal on the other mounting surface opposite to the one mounting surface of the circuit board;
An electronic pen position detection circuit. On the one mounting surface, the ultrasonic signal receiving unit is mounted at each of two corners on the medium side to be operated by the electronic pen, and
In the other mounting surface, mounting the infrared signal receiving unit at the center of the side on the medium side,
The electronic pen position detection circuit according to claim 1.   3. The electronic pen according to claim 2, wherein the one mounting surface is provided with a protruding portion extending from two corners on the medium side, and the ultrasonic signal receiving portion is mounted on the protruding portion. Position detection circuit. The ultrasonic signal transmitted from the ultrasonic signal transmitter from when the infrared signal transmitted from the infrared signal transmitter is received to detect the position of the electronic pen having the ultrasonic signal transmitter and the infrared signal transmitter. Is an electronic pen position detection device that obtains each time until it is received at a plurality of locations and detects the position of the electronic pen based on each time,
A plurality of ultrasonic signal receivers that receive the ultrasonic signals transmitted from the ultrasonic signal transmitter are mounted on one mounting surface of the circuit board, and opposite to the one mounting surface of the circuit board. An electronic pen position detection circuit for mounting an infrared signal receiving unit that receives the infrared signal transmitted from the infrared signal transmitting unit on the other mounting surface on the side,
A container for storing the electronic pen position detection circuit, and the infrared signal transmission filter is disposed on a surface of the container surrounding the other mounting surface on a medium side to be operated by the electronic pen. And a storage container in which an opening for capturing the ultrasonic signal is disposed on the medium side surface of the container surface surrounding the periphery of the one mounting surface;
An electronic pen position detection device comprising: An electronic pen having an ultrasonic signal transmitter and an infrared signal transmitter;
Obtain each time from when the infrared signal transmitted from the infrared signal transmitter is received to when the ultrasonic signal transmitted from the ultrasonic signal transmitter is received at a plurality of locations, and based on each time An electronic pen position detecting device for detecting the position of the electronic pen,
The electronic pen position detection device is
While mounting a plurality of ultrasonic signal receiving units that receive ultrasonic signals transmitted from the ultrasonic signal transmitting unit on one mounting surface of the circuit board housed in the apparatus,
Mounting an infrared signal receiving unit that receives an infrared signal transmitted from the infrared signal transmitting unit on the other mounting surface opposite to the one mounting surface of the circuit board;
An electronic pen position detection system. The ultrasonic signal transmitted from the ultrasonic signal transmitter from when the infrared signal transmitted from the infrared signal transmitter is received to detect the position of the electronic pen having the ultrasonic signal transmitter and the infrared signal transmitter. Is a circuit element mounting method of an electronic pen position detection circuit that obtains each time until it is received at a plurality of locations and detects the position of the electronic pen based on each time,
On one mounting surface of the circuit board, while mounting a plurality of ultrasonic signal receiving units that receive the ultrasonic signal transmitted from the ultrasonic signal transmitting unit,
Mounting an infrared signal receiving unit that receives an infrared signal transmitted from the infrared signal transmitting unit on the other mounting surface opposite to the one mounting surface of the circuit board;
A circuit element mounting method for an electronic pen position detection circuit.

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