JP3914421B2 - Pen type coordinate indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pen-type coordinate indicator that indicates a position to be measured to a position detection device such as a tablet that measures a position and notifies an operation of an operator.
[0002]
[Prior art]
Conventionally, a pointing device called a pen tablet has been used as an input device for a computer. The pen tablet is composed of a plate-like tablet and an input pen operated by an operator on the tablet. When the operator designates an arbitrary position on the tablet with the input pen, the position is detected by the tablet, and the position information is output to the computer.
[0003]
The present applicant has proposed various input pens for pen tablets as shown in, for example, Japanese Utility Model Publication No. 5-4034. Here, an example of a conventional input pen will be described with reference to FIG.
[0004]
FIG. 13 is a cross-sectional view showing a schematic configuration of an input pen 90 as an example of a conventional input pen. The input pen 90 accommodates each part on a pen shaft 91 formed in substantially the same shape as a writing instrument such as a ballpoint pen or a fountain pen.
[0005]
A core body 92 communicating with the inside of the pen shaft 91 is disposed at the tip of the pen shaft 91. The base end side of the core body 92 is inserted into a through hole of the ferrite core 94, and the base end portion of the core body 92 is fixed to the core holder 96. The lead holder 96 is fixed to the pen shaft 91 via a spring 97.
The core body 92 has a built-in ferrite chip 93. When the input pen 90 is not operated, about two-thirds of the ferrite chip 93 is in a through hole of the ferrite core 94. The core body 92 is supported by a spring 97 together with the core holder 96, and is movable along the expansion / contraction direction of the spring 97, that is, the axial direction of the pen shaft 91 and the through hole of the ferrite core 94.
[0006]
The ferrite core 94 is a ferrite formed in a cylindrical shape, has a through hole along the longitudinal direction, and a core body 92 is inserted therein. A coil 95 is wound around the outer surface of the ferrite core 94, and the coil 95 is connected to a capacitor 98 in the pen shaft 91 to form a tuning circuit 99.
[0007]
A tuning circuit 99 provided in the input pen 90 is supplied from a tablet (not shown) to a predetermined tuning frequency, for example, a frequency f.₀When the radio wave is transmitted, the radio wave is received and excited, and an induced voltage is induced in the coil 95. When the transmission of the radio wave is stopped, a radio wave having a predetermined frequency is transmitted from the coil 95 by a current based on the induced voltage. The position of the input pen 90 on the tablet (not shown) can be detected by receiving the radio wave transmitted from the tuning circuit 99 with a tablet (not shown).
[0008]
The input pen 90 is operated so as to press the tip of the pen shaft 91 against the tablet. During this operation, the core body 92 is pushed into the pen shaft 91, and the ferrite chip 93 built in the core body 92 moves toward the base end side inside the ferrite core 94.
[0009]
As described above, since the coil 95 is wound around the ferrite core 94, when the positional relationship between the both ends of the ferrite core 94 and the ferrite chip 93 changes, the inductance of the coil 95 changes. Therefore, in the tuning circuit 99 including the coil 95, the inductance of the coil 95 changes due to the movement of the ferrite chip 93, and the tuning frequency of the tuning circuit 99 changes.
[0010]
In this case, the frequency f from the tablet (not shown)₀When the radio signal is transmitted, the tuning frequency of the tuning circuit 99 is changed, so that the induced voltage generated in the coil 95 is out of phase with the non-operating state. For this reason, the tuning circuit 99 transmits a radio wave that is out of phase with the radio wave transmitted from the tablet (not shown).
Therefore, if the tuning circuit 99 is excited by transmitting a radio wave from a tablet (not shown), and the phase difference in the radio wave emitted from the tuning circuit 99 is detected, the operation of the input pen 90 can be detected.
[0011]
As illustrated above, the conventional pen tablet does not need to connect the tablet and the input pen, and a feeling of use similar to that of a normal writing instrument such as a fountain pen or a ballpoint pen is obtained, so that it is rich in operability. Have advantages.
[0012]
[Problems to be solved by the invention]
As described above, the conventional input pen exemplified by the input pen 90 has the same size as a normal writing instrument such as a ballpoint pen, and is particularly suitable for a stationary desktop computer or the like.
On the other hand, recently, portable electronic devices called PDA (Personal Digital Assistant) have become popular, and electronic devices have been downsized. For this reason, downsizing of an input device for use in a small electronic device is also desired. However, there is a problem that it is difficult to realize a significant downsizing without changing the structure of the conventional input pen.
[0013]
Taking the above-described input pen 90 as an example, in miniaturization, it is necessary to make the ferrite core 94 and the core body 92 thin, because it is necessary not only to make it short, but also to make it thin.
However, since the core body 92 includes the ferrite chip 93, if the core body 92 is thinned, the wall surface of the portion where the ferrite chip 93 is embedded becomes thin. In general, since the member such as the core 92 is often made of resin, the thickness becomes insufficient due to thinning, and there is a risk of plastic deformation due to a load during operation. When the core body 92 is deformed inside the ferrite core 94, the core body 92 may hit the inner wall of the ferrite core 94, and the core body 92 may not move. In this state, the input operation with the input pen 90 cannot be performed. Therefore, it is difficult to make the core 92 thin.
[0014]
On the other hand, since the ferrite core 94 has a through-hole into which the core body 92 is inserted, in order to make the ferrite core 94 thin, the through-hole must be made thin and thin. However, it is difficult to reduce the size of the core body 92 and ferrite is brittle as a structural material. If the core body 92 is made thinner than the limit, cracks may occur due to insufficient strength.
[0015]
For example, in the process of manufacturing the input pen 90, in the process of winding the coil 95 on the ferrite core 94, the tension of the wire is applied to the ferrite core 94. The process is performed with the ferrite core 94 fixed. Since stress concentrates on the fixed portion of the ferrite core 94 due to the tension of the wire rod, the ferrite core 94 is required to have appropriate robustness. Furthermore, the strength required for the ferrite core 94 is not small considering vibration during transportation and a drop impact test as a product.
[0016]
If the ferrite core 94 is broken, the inductance of the coil 95 is lowered from the initial value, and the tuning frequency of the tuning circuit 99 is shifted. Therefore, there is a possibility that it cannot be used as an input device.
[0017]
Therefore, in the example of the input pen 90, the core body 92 and the ferrite core 94 need to ensure a certain level of strength, and it is difficult to downsize the configuration of the input pen 90 as it is.
[0018]
Further, when the electronic device is downsized, the portability is improved, but there is a concern that the operability during the input operation is lowered. For this reason, an input device that is small and has good operability has been demanded.
[0019]
Therefore, the present invention realizes a finer configuration in a pen-type coordinate indicator that indicates a position to be measured to a position detection device such as a tablet for measuring a position and notifies an operator's operation. For the purpose.
[0020]
Another object of the present invention is to ensure good operability in a thin pen-type coordinate indicator.
[0021]
[Means for Solving the Problems]
In order to solve such a problem, the present invention has the following features. In the following description, a configuration corresponding to the embodiment is shown as an example in parentheses. Reference numerals and the like are reference numerals for drawings to be described later.
[0022]
  The pen-type coordinate indicator according to the invention of claim 1 is a pen-type coordinate indicator that indicates the position to be measured and notifies the operator's operation to the position detection device that measures the position, Has an end face without an openingCylindrical shapeA coil (105) wound around a core (eg, ferrite core 104 shown in FIG. 1);A cylindrical magnetic body (for example, the ferrite chip 102 shown in FIG. 1) disposed opposite to the end surface of the core, which is separated from the core and approaches according to the operation of the operator along the axis of the coil. )When,An elastic body (for example, a figure) interposed between the end surface of the core and the magnetic body 1 The elastic body is an annular member having a through hole communicating with the end surface of the core and the opposing surface of the magnetic body, and the end surface of the core Of the surfaces of the magnetic material that are in contact with each other and facing the end surface of the core, they are in contact with only a portion of the facing surface, and a portion of the end surface of the core and the magnetic material A protruding portion is formed on one or both of the opposing portions without the elastic body being a part of the opposing surface, and the protruding portion has a side surface along the inner surface of the elastic body. The height of the protrusion isThan the thickness of the elastic bodySmall heightIt is characterized by becoming.
[0023]
Here, as the position detecting device, for example, a plurality of loop coils are provided in a flat plate-shaped case, radio waves of a predetermined oscillation frequency are transmitted from these loop coils, and the pen-type coordinate indicator in the pen-type coordinate indicator is transmitted by the radio waves. Examples include detecting the position of a pen-type coordinate indicator based on the voltage induced in the coil, but it may be configured integrally with a display screen such as a liquid crystal display panel, and the shape is It may be other than a flat plate. Moreover, as said magnetic body, a soft ferrite is mentioned, for example. Furthermore, examples of the core include members using magnetic materials such as soft ferrite and other various metals.
[0024]
According to the first aspect of the present invention, the pen-type coordinate indicator that indicates the position to be measured and notifies the operator's operation to the position detecting device that measures the position has an end face without an opening. A coil wound around the core and a magnetic body disposed opposite to the end surface of the core along the axis of the coil, the core and the magnetic body being spaced apart from each other; Approach according to the operation. Moreover, there is no opening in the end surface of the core, and the magnetic body does not enter the inside of the coil even if the magnetic body and the core approach each other.
[0025]
Therefore, in the pen-type coordinate indicator according to the present invention, when the magnetic body approaches the coil core, the inductance of the coil is changed, and the position detection device for measuring the position is notified of the operation of the operator. Can do.
In addition, since it is not necessary to provide an opening on the end face of the core, there is no possibility of causing insufficient strength of the core even if the core is thinned. Thereby, a very thin pen-type coordinate indicator can be realized by forming the core thin and disposing the core and the magnetic body along the axis of the coil.
[0026]
Further, when the operation is performed by the operator, the core and the magnetic body are close to each other, so that the inductance of the coil is changed in an increasing direction. A coordinate indicator used together with a position detection device may employ an LC resonance circuit using a variable capacitor whose capacity changes during pressurization in order to detect an operation. Such a coordinate indicator increases the capacity of the variable capacitor when an operation by the operator is applied, and as a result, the resonance frequency of the LC resonance circuit shifts to a lower side, and has a high sensitivity but a complicated structure. Yes and expensive. In the pen-type coordinate indicator according to the present invention, since the inductance of the coil increases during operation, if the LC resonance circuit including the coil is configured, the resonance frequency is shifted toward the lower side during operation. Therefore, a pen-type coordinate indicator that performs the same operation as a coordinate indicator using a variable capacitor can be realized at a low cost with a simpler configuration.
Furthermore, the change in inductance of the coil during operation becomes more conspicuous as the coil and the magnetic body are closer to each other. For this reason, if the predetermined distance between the coil and the magnetic body in the initial state is shortened, the operation can be detected more reliably, and a smaller pen-type coordinate indicator can be realized.
[0029]
  Also coreIn an initial state where there is no operation, the core and the magnetic body are held apart from each other by an elastic body interposed between the end surface of the core and the magnetic body. The magnetic bodies are urged away from each other, and the initial state is restored after the operation.
[0030]
Therefore, since the restoration operation after the operation is performed smoothly, a pen-type coordinate indicator with good operability can be realized. That is, a response during operation is good and a mechanism for quick restoration is realized with a simple configuration, which can be easily reduced in size and reduced in cost. In general, the amount of deformation when force is applied to the elastic body corresponds to the magnitude of the applied force. Therefore, the amount of deformation of the elastic body is obtained from the amount of change in coil inductance, and the force applied during operation is obtained. Is also possible.
[0033]
Therefore, compared with the case where the entire end surface of the core or the entire opposing surface of the magnetic body is covered with an elastic body, the inductance of the coil changes significantly during operation. Furthermore, when a force greater than the elasticity of the elastic body is applied during the operation, the core and the magnetic body are very close to or in contact with each other, and the inductance of the coil changes more greatly.
Thereby, since the operation by the operator is detected sharply and reliably, it is possible to realize a pen-type coordinate indicator with good response and good operability.
[0035]
  The invention of claim 1According to the present invention, at least one of the end surface of the core and the facing surface of the magnetic body that faces the end surface of the core is formed with a protruding portion that is lower than the thickness of the elastic body. In the facing portion, the protrusion and the surface or the protrusions face each other. That is, compared with the case where there is no protrusion, the core and the magnetic body are closer to each other in the initial state, and the core and the magnetic body are closer to each other during operation. Moreover, the height of the protrusion is lower than the thickness of the elastic body, and the core and the magnetic body do not contact in the initial state.
[0036]
Since the influence of the magnetic body on the inductance of the coil is inversely proportional to the square of the distance between the coil and the magnetic body, the closer the core and the magnetic body are, the more rapidly the inductance of the coil changes during operation.
Since the pen-type coordinate indicator according to the present invention includes the protruding portion, the interval between the elastic body and the core in the initial state can be reduced, and the core and the magnetic body can be brought close to each other quickly during operation. In addition, since the height of the protruding portion is lower than the thickness of the elastic body, it is sufficient to sandwich the elastic body as a configuration for separating the core and the magnetic body during non-operation. can avoid.
Accordingly, the inductance of the coil changes sharply during operation, and the operator's operation can be reliably detected on the position detection device side, so that a pen-type coordinate indicator that exhibits good response and good operability can be realized.
[0041]
  Claims 1 According to the invention described inThe elastic body is an annular member that is in line contact with the core and the magnetic body, such as an O (O) ring, and easily elastically deforms when the core and the magnetic body approach each other. And the said protrusion part has a side surface along the inner surface of an elastic body, protrudes in the space in the center part of an elastic body, and the inner surface of an elastic body and the side surface of a protrusion part contact | abut. The elastic body is supported.
[0042]
Therefore, even if it is operated with a weaker force, the elastic body is reliably deformed and the core and the magnetic body approach each other, so a pen-type coordinate indicator that has a low resistance during operation and can be operated with a relatively weak force. realizable. In addition, since the protrusion supports the elastic body, the relative position of the core, the magnetic body, and the elastic body can be prevented from shifting during use, and a pen-type coordinate indicator with higher reliability can be realized. Furthermore, it is easy to align the core and the magnetic body along the axis of the core and dispose the elastic body between the core and the magnetic body.
[0043]
  Also,Claim 2In the pen-type coordinate indicator described,Claim 1In the described pen-type coordinate indicator,The core and the magnetic body are accommodated in a pen-type case, and a core (101) that is inserted into and out of the case is disposed at the tip of the case, and the magnetic body is connected to the base end portion of the core.It is characterized by that.
[0044]
  Claim 2According to the described invention, the core and the magnetic body are accommodated in the pen-shaped case, and the tip of the case is provided with the core inserted into the inside and outside of the case, and the magnetic body is the core on the outside of the core. When the core is pushed into the case by the operation of the operator, the magnetic body moves together with the core and approaches the core to change the inductance of the coil.
[0045]
Therefore, even if the magnetic body moves reliably with respect to the operation of the operator and the force due to the operation is difficult to be transmitted, for example, when the operator tilts the case and operates the magnetic body, approach. Thereby, it is possible to realize a pen-type coordinate indicator that responds reliably to the operation of the operator and has good operability.
In addition, since the magnetic body is outside the core, it is not necessary to provide a space for accommodating the magnetic body inside the core, and the core can be made thin. That is, if a space is formed inside the core to accommodate the magnetic material in the core, the wall portion of the space becomes thin, so the core must be thickened in order to ensure strength to withstand use. I don't get it. However, in the pen-type coordinate indicator according to the present invention, since the core does not contain a magnetic material, there is no fear that the strength is insufficient even if the core is thinned. For this reason, a finer pen-type coordinate indicator can be realized by forming a thin core. In addition, if the lead is made thinner, the hole at the tip of the case for inserting the lead can be made smaller, so the case can be made thinner, and the tip that functions as the pen tip can be made thinner for fine operations. Improved operability. Furthermore, for example, when a core, a magnetic body, an elastic body, and a core are arranged in series along the axis of the core, the case can be made very thin, and a finer pen-type coordinate indicator can be realized.
[0046]
  Claim 3The described inventionClaim 2The pen-shaped coordinate indicator according to claim 1, wherein an inner diameter of the hollow portion is narrowed at a distal end side of the case in the hollow portion of the case housing the core and the magnetic body.Step(For example, stepped portion B shown in FIG. 16) is formed, and the end surface of the core facing the magnetic body is formed in the hollow portion.StepIt arrange | positions so that it may contact | abut.
[0047]
  Claim 3According to the described invention, the hollow portion of the case housing the core and the magnetic body is formed with a step in which the inner diameter of the hollow portion is narrowed on the tip end side of the case, and the end surface of the core facing the magnetic body is Since it arrange | positions so that it may contact | abut to the step formed in the hollow part, the core is supported by the step so that it may not move outside from the hollow part of a case. As a result, the core does not move during use of the pen-type coordinate indicator of the present invention, and a stable operation feeling without rattling can be realized. Further, it is not necessary to use a technique such as adhesion to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0048]
  Claim 4The described inventionClaim 2 or 3In the pen-type coordinate indicator described above, a second elastic body (for example, FIG. 15) interposed between an end surface of the core that does not face the magnetic body and a base end portion of the hollow portion of the case. And a buffer member 707) shown in FIG.
[0049]
  Claim 4According to the described invention, since the second elastic body is interposed between the end surface of the core not facing the magnetic body and the base end portion of the hollow portion of the case, the elasticity of the second elastic body Can support the core. Even if there is a tolerance in the size of the core in the longitudinal direction, this tolerance can be absorbed by the elasticity of the second elastic body, and the core can be reliably supported regardless of the tolerance of the core. Can realize a stable operation feeling. Further, the pen-type coordinate indicator to which the present invention is applied does not need to correct the core tolerance, and can be easily manufactured with a small number of man-hours.
[0050]
  Claim 5The described inventionClaim 4In the pen-type coordinate indicator described above, a support member (for example, a substrate holder 703 shown in FIG. 15) interposed between the end surface of the core that does not face the magnetic body and the second elastic body. The support member further includes a core holding protrusion (for example, a core holding protrusion 721 shown in FIG. 16) that protrudes toward the end surface of the core, and the end surface of the core that contacts the support member has the core A concave portion that fits into the holding projection is formed.
[0051]
  Claim 5According to the described invention, the support member is interposed between the end surface of the core not facing the magnetic body and the second elastic body, and the support member has the core holding projection protruding toward the end surface of the core. A recess that fits with the core holding projection is formed on the end surface that contacts the support member of the core, so that the core holding projection and the recess of the core are fitted, and the second elastic body and the support member Since the core is supported by, the core can be reliably supported. As a result, the core does not move during use of the pen-type coordinate indicator of the present invention, and a stable operation feeling without rattling can be realized. Further, it is not necessary to use a technique such as adhesion to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0054]
  Claim 6The described inventionClaims 2-5In the pen-type coordinate indicator according to any one of the above, the hollow portion of the case that accommodates the core and the magnetic body has a second narrower inner diameter at the distal end side of the case.Step(For example, a step C shown in FIG. 16) is formed, and a flat portion parallel to the transverse section of the case is formed at the base end portion of the core, and the core is formed in the hollow portion of the case. Second madeStepIt arrange | positions so that the said plane part may touch.
[0055]
  Claim 6According to the described invention, the second step in which the inner diameter of the hollow portion is narrowed on the distal end side of the case is formed in the hollow portion of the case that accommodates the core and the magnetic body, and the transverse section of the case is formed at the proximal end portion of the core. Is formed so that the flat portion is in contact with the second step formed in the hollow portion of the case, and the second step does not move the core to the outside of the case. To be held. Thereby, since the lead does not move to the outside of the case, it is possible to realize a stable operation feeling without rattling. Further, it is not necessary to use a technique such as bonding the core and a magnetic material to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0056]
  Claim 7The described inventionClaim 6In the pen-type coordinate indicator described above, a magnetic body holding protrusion (for example, a chip holding protrusion 722 shown in FIG. 16) further protrudes toward the end surface of the magnetic body on the flat surface portion formed at the base end portion of the core. ), And a concave portion that fits with the magnetic material holding protrusion is formed on an end surface of the magnetic material that is in contact with the core.
[0057]
  Claim 7According to the described invention, the flat portion formed at the base end portion of the core is further formed with the magnetic body holding projection that protrudes toward the end surface of the magnetic body, and the end surface in contact with the core of the magnetic body is magnetically Since the concave portion for fitting with the body holding projection is formed, the magnetic body holding projection and the concave portion of the magnetic body are fitted, so that the magnetic body and the core are supported in an integrated state. As a result, the core does not move toward the outside of the case or moves in the cross-sectional direction of the case, and a stable operational feeling without rattling can be realized. Further, it is not necessary to use a technique such as bonding the core and a magnetic material to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0058]
In addition, the code | symbol shown in the parenthesis in the above description shows the drawing reference code corresponding to the component requirement of a claim as an example to the last, and does not specifically limit the component requirement of a claim. No.
[0059]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS.
[0060]
[First Embodiment]
FIG. 1 is a cross-sectional view showing a configuration of an input pen 10 according to the first embodiment of the present invention. In the figure, 11 is a case, 12 is a substrate holder, 13 is a substrate, 14 is a capacitor, 15 is a tuning circuit, 101 is a core, 102 is a ferrite chip, 103 is an O (O) ring, 104 is a ferrite core, 105 is The coil 102 a is a protrusion provided on the ferrite chip 102. FIG. 1 shows the input pen 10 in a non-operation state.
[0061]
The case 11 is a hollow housing made of a synthetic resin such as an ABS resin or a metal, which is made in a smaller size, imitating a general writing instrument such as a ballpoint pen or a mechanical pencil, and is hollow. A rod-shaped core 101 that is inserted into and out of the case 11 is disposed at the distal end of the case 11, and a ferrite chip 102 is fixed to the proximal end portion of the core 101. The ferrite chip 102 is a piece of ferrite magnet such as soft ferrite, for example, and faces the tip of the ferrite core 104 via a flexible O-ring 103.
[0062]
The ferrite core 104 is a rod-shaped ferrite having a circular or square cross section, and is disposed so that the distal end surface faces the ferrite chip 102, and the base end portion is fixed to the substrate 13. A coil 105 is wound around the side surface of the ferrite core 104.
[0063]
The board 13 is a printed board or the like on which a capacitor 14 or the like is mounted, and is fixed to the case 11 via the board holder 12. The capacitor 14 is a known element. The tuning circuit 15 includes an element such as the capacitor 14 mounted on the substrate 13 and the coil 105.
[0064]
Here, the front end surface of the ferrite core 104 is formed to be substantially smooth, and, for example, a columnar protrusion 102 a is formed at substantially the center of the surface of the ferrite chip 102 facing the front end surface of the ferrite core 104.
[0065]
The O-ring 103 is a ring made of synthetic resin, synthetic rubber, or the like in the shape of the letter “O”. The O-ring 103 has a through hole at the center of the plane, and the protrusion 102a of the ferrite chip 102 is inserted into the through hole. is doing.
[0066]
Therefore, the end face of the ferrite core 104 and the protrusion 102a are opposed to each other through the O-ring 103. The O-ring 103 holds the ferrite chip 102 and the ferrite core 104 apart from each other, and elastically deforms when a pressing force is applied in a direction in which the ferrite chip 102 and the ferrite core 104 are brought close to each other.
[0067]
Note that the O-ring 103 is made of an elastic body such as silicon rubber, and is preferably made of pure silicon, more preferably rubber hardness, considering the recovery to the initial state after the pressing force is applied. 30 degree pure silicon.
The core 101 is preferably made of a synthetic resin such as polyacetal resin (Duracon) in consideration of resistance to friction during sliding.
[0068]
The input pen 10 is operated on a substantially flat tablet 20 (FIG. 2). At the time of operation, the input pen 10 is held so that the tip of the case 11 faces downward as in a normal writing instrument, and the lead 101 is pressed against the tablet (FIG. 2).
[0069]
Accordingly, when the input pen 10 is operated, the lead 101 is pushed into the case 11, whereby the ferrite chip 102 is pressed together with the lead 101 toward the ferrite core 104, the O-ring 103 is elastically deformed, and the ferrite tip 102 becomes ferrite. Approach the core 104.
[0070]
When the ferrite chip 102 approaches the ferrite core 104, the inductance of the coil 105 wound around the ferrite core 104 changes. That is, in the input pen 10, the inductance of the coil 105 changes during operation.
[0071]
Next, the coordinate input device 1 including the input pen 10 will be described.
FIG. 2 is a circuit diagram showing a configuration of the coordinate input device 1. In the figure, 20 is a tablet, 30 is a control circuit, 31 is a signal generation circuit, 32 and 33 are X and Y direction selection circuits, 34 and 35 are transmission / reception switching circuits, 36 is an XY switching circuit, and 37 is reception timing switching. Circuit, 38 is a band pass filter (BPF), 39 is a detector, 40 is a low pass filter (LPF), 41 and 42 are phase detectors (PSD), 43 and 44 Is a low-pass filter (LPF), 45 and 46 are drive circuits, 47 and 48 are amplifiers, 49 is an electronic device, 50 is a display device, and 51 is an output device.
[0072]
As the electronic device 49, for example, a personal computer, a PDA (Personal Digital Assistant), a portable terminal device having a wireless communication function, or the like, which is integrated with an external display device 50 such as an LCD (Liquid Crystal Display) or the like. Is mentioned. Examples of the output device 51 include a printing device, a wireless communication device, various disk drives, and various semiconductor memory devices that are integrated with or externally connected to the electronic device 49.
[0073]
FIG. 3 is an exploded perspective view showing the main configuration of the tablet 20 shown in FIG. 2. Specifically, the arrangement state of the X-direction loop coil group 21 and the Y-direction loop coil group 22 constituting the tablet 20 is shown. FIG.
As shown in FIG. 3, the tablet 20 includes an X-direction loop coil group 21 extending in a direction indicated by a reference sign X in the drawing and a Y-direction loop coil group 22 extending in a direction indicated by a reference sign Y in the drawing. Is done. Note that the directions indicated by the symbols X and Y in the figure are orthogonal to each other.
[0074]
The loop coil group 21 in the X direction is composed of a number of loop coils, for example, 48 loop coils 21-1, 21-2,. Further, the loop coil group 22 in the Y direction has a large number of loop coils arranged parallel to and overlapping each other along the Y direction, for example, 48 loop coils 22-1, 22-2,. 48.
[0075]
The X-direction loop coil group 21 and the Y-direction loop coil group 22 are closely overlapped with each other, and are housed in a case made of a non-metallic material (not shown). In FIG. 3, the loop coil group 21 and the loop coil group 22 are illustrated separately for convenience of understanding. Moreover, although each loop coil shown with the code | symbol 21-1 to 21-48 and 22-1 to 22-48 is illustrated as what is comprised by 1 turn, it is good also as a structure which makes several turns as needed. .
[0076]
Next, the configuration and operation of the coordinate input device 1 will be described.
First, transmission / reception of radio waves between the input pen 10 and the tablet 20 and signals obtained at that time will be described with reference to the timing charts shown in FIGS. In the timing chart of FIG. 4, as will be described later, with respect to substantially the same signal, only one chart is illustrated with reference numerals.
[0077]
The control circuit 30 shown in FIG. 2 is configured by a known microprocessor or the like, controls the signal generation circuit 31, and switches each loop coil of the tablet 20 via the selection circuits 32 and 33 according to the flowchart of FIG. Control. The control circuit 30 controls the coordinate detection direction switching for the XY switching circuit 36 and the reception timing switching circuit 37.
Further, the control circuit 30 performs analog / digital (A / D) conversion on the output values from the low-pass filters 40, 43, and 44, and executes arithmetic processing described later to obtain the coordinate value of the indicated position by the input pen 10. The phase of the received signal is detected and sent to the electronic device 49.
[0078]
The selection circuit 32 sequentially selects one loop coil from the loop coil group 21 in the X direction (see FIG. 3). The selection circuit 33 sequentially selects one loop coil from the loop coil group 22 in the Y direction (see FIG. 3). These selection circuits 32 and 33 operate according to information from the control circuit 30, respectively.
The transmission / reception switching circuit 34 alternately connects one loop coil in the X direction selected by the selection circuit 32 to the drive circuit 45 and the amplifier 47. The transmission / reception switching circuit 35 alternately connects one loop coil in the Y direction selected by the selection circuit 33 to the drive circuit 46 and the amplifier 48. The transmission / reception switching circuits 34 and 35 are transmission / reception switching described later. Operate according to signal C.
[0079]
The signal generation circuit 31 has a predetermined frequency f₀For example, a rectangular wave signal A of 500 kHz (kilohertz), a signal B obtained by delaying the phase of the rectangular wave signal A by 90 ° (degree: Degree), a predetermined frequency f_kFor example, a transmission / reception switching signal C and a reception timing signal D of 16.625 kHz are generated and output.
[0080]
The rectangular wave signal A output from the signal generation circuit 31 is sent to the phase detector 41 as it is, converted to a sine wave signal E by a low-pass filter (not shown), and further via a XY switching circuit 36 to a drive circuit 45. , 46. The rectangular wave signal B output from the signal generation circuit 31 is sent to the phase detector 42, the transmission / reception switching signal C is sent to the transmission / reception switching circuits 34 and 35, and the reception timing signal D is received by the reception timing switching circuit 37. Is sent out.
[0081]
When the information for selecting the X direction is output from the control circuit 30 and is input to the XY switching circuit 36 and the reception timing switching circuit 37, the sine wave signal E output from the signal generation circuit 31 is sent to the drive circuit 45. Then, it is converted into a balanced signal and further sent to the transmission / reception switching circuit 34. Here, since the transmission / reception switching circuit 34 switches and connects either the drive circuit 45 or the amplifier 47 based on the transmission / reception switching signal C, the signal output from the transmission / reception switching circuit 34 to the selection circuit 32 is the time T (= 1 / 2f_k), According to the above example, the signal F is repeatedly output / stopped at 500 kHz every 32 μsec (microseconds).
Then, the signal F output from the transmission / reception switching circuit 34 is sent to one loop coil 21-i (i = 1, 2,..., 48) in the X direction of the tablet 20 via the selection circuit 32. In 21-i, a radio wave based on the signal F is generated.
[0082]
Here, a period in which the signal F is output is a transmission period, and a period in which the signal F is not output is a reception period. As shown in the timing chart of FIG. 4, the transmission period and the reception period are alternately repeated every time T.
[0083]
When the input pen 10 is held in a substantially upright state, that is, in use, on the tablet 20, the coil 105 (FIG. 1) of the input pen 10 is excited by radio waves generated from the loop coil 21-i, and the tuning circuit 15 ( In FIG. 1), an induced voltage G synchronized with the signal F is generated.
[0084]
Thereafter, when the operation of the transmission / reception switching circuit 34 enters a period in which there is no signal in the signal F, that is, a reception period and the loop coil 21-i is switched to the amplifier 47 side, the radio wave from the loop coil 21-i immediately disappears. However, the induced voltage G generated in the tuning circuit 15 of the input pen 10 gradually attenuates according to the loss in the tuning circuit 15.
[0085]
A radio wave is transmitted from the coil 105 by the current flowing through the tuning circuit 15 based on the induced voltage G. The loop coil group 21-i connected to the amplifier 47 is excited by the radio wave transmitted from the coil 105, and an induced voltage due to the radio wave from the coil 105 is generated in the loop coil group 21-i. This induced voltage is sent from the transmission / reception switching circuit 34 to the amplifier 47 only during the reception period, amplified, and sent to the reception timing switching circuit 37 as a reception signal H.
[0086]
The reception timing switching circuit 37 receives either selection information in the X direction or the Y direction, here, selection information in the X direction and a reception timing signal D that is substantially an inverted signal of the transmission / reception switching signal C. ing. The reception timing switching circuit 37 outputs the reception signal H while the signal D is at the “Hi” level, and outputs nothing during the period when the signal D is at the “Lo” level. To do.
[0087]
The signal I is sent to the band filter 38. The bandpass filter 38 has a frequency f₀Is a ceramic filter having a natural frequency, and the frequency f in the signal I is₀A signal J having an amplitude corresponding to the component energy is sent to the detector 39 and the phase detectors 41 and 42. Strictly speaking, the band filter 38 sends these signals J to the detector 39 and the phase detectors 41 and 42 in a state where several signals I are input to the band filter 38 and converged.
[0088]
The signal J input to the detector 39 is detected and rectified to be a signal K, and then a DC value having a voltage value corresponding to approximately half of the amplitude, for example, Vx, by the low-pass filter 40 having a sufficiently low cutoff frequency. The signal L is converted and sent to the control circuit 30.
[0089]
The voltage value Vx of the signal L is based on the induced voltage induced in the loop coil 21-i, and is a value depending on the distance between the input pen 10 and the loop coil 21-i, which is approximately 4 in this case. The value is inversely proportional to the power. For this reason, when the loop coil 21-i is switched to a different loop coil, the voltage value Vx of the signal L becomes a different value.
[0090]
Accordingly, the control circuit 30 obtains the positional relationship between each loop coil and the input pen 10 by converting the voltage value Vx obtained for each loop coil into a digital value and performing arithmetic processing described later on the digital value. Thus, the coordinate value in the X direction of the position indicated by the input pen 10 is obtained. Note that the coordinate value in the Y direction of the position indicated by the input pen 10 is obtained in the same manner.
[0091]
On the other hand, the rectangular wave signal A generated by the signal generation circuit 31 is input to the phase detector 41 as a detection signal, and the rectangular wave signal B whose phase is 90 ° behind the rectangular wave signal A is input to the phase detector 42. Is input as a detection signal.
When the phase of the signal J substantially matches the phase of the rectangular wave signal A, the phase detector 41 outputs the signal M1 obtained by inverting the signal J to the positive side, and the phase detector 42 is positive. A signal M2 having a symmetrical waveform on the side and the negative side is output. The signal M1 output from the phase detector 41 is substantially the same as the signal K.
[0092]
Similarly to the signal K, the signal M 1 is converted into a DC signal N 1 having a voltage value corresponding to approximately half of the amplitude of the signal J, that is, Vx, by the low-pass filter 43, and sent to the control circuit 30. Here, the DC signal N1 is substantially the same as the signal L.
Similarly, the signal M2 is converted into a DC signal N2 by the low-pass filter 44 and sent to the control circuit 30. In the example shown in FIG. 4, the positive and negative sides of the signal M2 from the phase detector 42 are shown. Since the components are the same, the output voltage value of the low-pass filter 44 is 0 [V].
[0093]
The control circuit 30 converts the output values of the low-pass filters 43 and 44, here, the signals N1 and N2 into digital values, and executes the arithmetic processing represented by the following equation (1) using the obtained digital values. Thus, the phase difference θ between the signal applied to the phase detectors 41 and 42, here, the signal J and the rectangular wave signal A is obtained.
[Expression 1]
θ = -tan^-1(VQ / VP) (1)
[0094]
In the above equation (1), VP represents a digital value corresponding to the output of the low-pass filter 43, and VQ represents a digital value corresponding to the output of the low-pass filter 44.
For example, in the case of the signal J described above, the voltage value of the signal N1 is Vx, but the voltage value of the signal N2 is 0 [V], that is, VQ = 0, so that the phase difference θ = 0 °.
[0095]
Incidentally, the phase of the signal J changes corresponding to the tuning frequency in the tuning circuit 15 of the input pen 10. That is, the tuning frequency in the tuning circuit 15 is a predetermined frequency f.₀, The tuning circuit 15 has a frequency f in both the signal transmission period and the reception period.₀And an induced current synchronized therewith flows, so that the frequency and phase of the received signal H (or I) coincide with the rectangular wave signal A, and the phase of the signal J also has the rectangular wave signal. Match A.
[0096]
On the other hand, the tuning frequency in the tuning circuit 15 is a predetermined frequency f.₀For example, the frequency f₀Slightly lower frequency f₁In this case, the tuning circuit 15 has a frequency f in the transmission period.₀The induced voltage causes an induced current with a phase delay to flow through the tuning circuit 15. In the reception period, the frequency f₁Inductive voltage is generated and an induced current synchronized therewith flows, so that the frequency of the reception signal H (or I) is slightly lower than the frequency of the rectangular wave signal A and the phase thereof is slightly delayed.
[0097]
As described above, the bandpass filter 38 has the frequency f.₀Therefore, the frequency shift to the lower side of the input signal is output as a phase delay, and therefore the phase of the signal J is higher than that of the received signal H (or I). It will be further delayed.
[0098]
Conversely, the tuning frequency in the tuning circuit 15 is a predetermined frequency f.₀If it is slightly higher, eg frequency f₂, The tuning circuit 15 has a frequency f during the transmission period.₀Inductive voltage is generated, and an induced current with phase advance flows through the tuning circuit 15. In the reception period, the frequency f₂Therefore, the frequency of the reception signal H (or I) is slightly higher than the frequency of the rectangular wave signal A, and the phase thereof is slightly advanced. In the band-pass filter 38, the frequency shift to the higher side of the input signal is output as a phase advance contrary to the case described above, and therefore the phase of the signal J is higher than that of the received signal H (or I). It goes even further.
[0099]
As described above, in the input pen 10, the ferrite chip 102 approaches the ferrite core 104 during operation. Therefore, when the input pen 10 is operated, the inductance of the coil 105 increases, and the tuning frequency of the tuning circuit 15 changes to a low frequency. This change in tuning frequency corresponds to the amount of change in inductance of the coil 105, that is, the amount of deformation of the O-ring 103.
Therefore, the amount of deformation of the O-ring 103, that is, the force applied when operating the input pen 10 is detected based on the value of the phase difference θ obtained by the arithmetic processing represented by the expression (1) by the control circuit 30. be able to.
[0100]
Next, the coordinate detection operation and the phase detection operation instructed by the input pen 10 will be described in detail with reference to FIGS. FIG. 5 is a flowchart showing the operation of the control circuit 30. FIG. 6 is a timing chart showing a signal detection operation in the tablet 20. In FIG. 6, (a) shows a sine wave signal sent to the loop coil of the tablet 20, and (b) shows a transmission period and a reception period. (C) shows the detected voltage in the loop coil of the tablet 20.
[0101]
First, when the power of the entire coordinate input device 1 is turned on and the measurement is started, the control circuit 30 (FIG. 2) sends information for selecting the X direction to the XY switching circuit 36 and the reception timing switching circuit 37. Among the X-direction loop coils 21-1 to 21-48 (FIG. 3) of the tablet 20, information for selecting the first loop coil 21-1 is sent to the selection circuit 32, and the loop coil 21-1 is switched between transmission and reception. Connect to circuit 34.
[0102]
Subsequently, the transmission / reception switching circuit 34 alternately connects the loop coil 21-1 to the drive circuit 45 and the amplifier 47 based on the transmission / reception switching signal C output from the signal generation circuit 31. At this time, the drive circuit 45 outputs 16 sine wave signals of 500 kHz as shown in FIG. 6A to the loop coil 21-1 in the transmission period of 32 μsec.
[0103]
Switching between transmission and reception by the transmission / reception switching circuits 34 and 35 is repeated seven times for one loop coil, here 21-1, as shown in FIG. 6B. The seven repetition periods of transmission and reception correspond to one loop coil selection period (448 μsec).
[0104]
The selection period of 448 μsec includes seven reception periods for one loop coil, and an induced voltage is obtained for each reception period as an output of the amplifier 47.
The induced voltage obtained here is sent to the band-pass filter 38 via the reception timing switching circuit 37 and averaged as described above, and the detector 39, the phase detectors 41 and 42, and the low-pass filters 40, 43, and 44. And then sent to the control circuit 30.
[0105]
Then, the control circuit 30 inputs the output value of the low-pass filter 40 after A / D conversion, and temporarily stores it as a detection voltage that depends on the distance between the input pen 10 and the loop coil 21-1, for example, Vx1.
[0106]
Next, the control circuit 30 sends information for selecting the loop coil 21-2 to the selection circuit 32, and connects the loop coil 21-2 to the transmission / reception switching circuit 34. Then, the detection voltage Vx2 proportional to the distance between the input pen 10 and the loop coil 21-2 is obtained and stored, and thereafter the loop coils 21-3 to 21-48 are sequentially connected to the transmission / reception switching circuit 34 in the same manner. The detected voltages Vx1 to Vx48 depending on the distance in the X direction from the input pen 10 for each loop coil as shown in FIG. 6 (c) (however, only a part of them is analog in FIG. 6 (c)). (Shown in a typical expression) is stored (FIG. 5: step S1).
[0107]
Actually, since the operation for obtaining the detection voltage in all the loop coils is time-consuming and inefficient, the number before and after the loop coil closest to the position (xp) where the input pen 10 is placed is the center. A detection voltage can be obtained for only one loop coil. Note that the detected voltage in loop coils other than these several loop coils is a negligible value.
[0108]
The control circuit 30 checks whether or not the voltage value of the detection voltage stored by the processing in step S1 is equal to or higher than a certain detection level (step S2), and if it is below the certain detection level (step S3; No) Again, selection of each loop coil in the X direction and voltage detection are repeated. If the detected level is equal to or higher than a certain detection level (step S3; Yes), the process proceeds to the next process.
[0109]
In the level check executed in step S2, the control circuit 30 determines whether or not the maximum value of the detection voltage has reached the detection level, and which loop coil has the maximum detection voltage. If the detection level has not been reached, the subsequent coordinate calculation or the like is stopped, or processing for setting the center of the loop coil to be selected in the next coordinate detection operation and phase detection operation is performed.
[0110]
Subsequently, the control circuit 30 sends selection information in the Y direction to the XY switching circuit 36 and the reception timing switching circuit 37, and switches to the selection circuit 33 and the transmission / reception switching circuit 35 in the same manner as in step S1. Detected voltage depending on the distance between the input pen 10 obtained by performing A / D conversion on the output value of the low-pass filter 40 when transmitting and receiving radio waves and the loop coils 22-1 to 22-48 in the Y direction Is temporarily stored (step S4).
[0111]
Thereafter, the control circuit 30 performs a level check of the stored detection voltage (step S5). If the level is below a certain detection level (step S6; No), the selection and selection of each loop coil in the X direction are performed again. Return to voltage detection. If the detected level is equal to or higher than a certain detection level (step S6; Yes), the coordinate values in the X direction and Y direction of the position indicated by the input pen 10 are calculated from the stored voltage value (step S7).
[0112]
Here, an example of the process in step S7 will be described.
As one of the calculation methods for obtaining the coordinate value in the X direction or the Y direction, for example, the coordinate value xp, the waveform near the maximum value of the detection voltages Vx1 to Vx48 is approximated by an appropriate function, and the coordinate of the maximum value of the function is obtained. There is a way to ask.
[0113]
For example, when the maximum detection voltage Vx3 shown in FIG. 6C and the detection voltages Vx2 and Vx4 on both sides thereof are approximated by a quadratic function, they can be calculated as follows.
In the following formulas (2) to (7), the coordinate values of the center positions of the loop coils 21-1 to 21-48 are x1 to x48, and the interval is Δx.
[0114]
First, the following formulas (2), (3), and (4) hold for each detection voltage and coordinate value. In the following formulas (2) to (4), a and b are constants (a <0).
[Expression 2]
Vx2 = a (x2-xp)²+ B (2)
Vx3 = a (x3-xp)²+ B (3)
Vx4 = a (x4-xp)²+ B (4)
[0115]
Further, the following formulas (5) and (6) are established for the coordinate value of the center position of each loop coil.
[Equation 3]
x3−x2 = Δx (5)
x4−x2 = 2Δx (6)
[0116]
Here, when the formulas (5) and (6) are substituted into the formulas (3) and (4) and rearranged, the following formula (7) is derived.
[Expression 4]
xp = x2 + Δx / 2 {(3Vx2-4Vx3 + Vx4) / (Vx2-2Vx3 + Vx4)} (7)
[0117]
In this way, the maximum detection voltage obtained at the level check in step S2 and the detection voltages before and after that are extracted from the detection voltages Vx1 to Vx48 from each loop coil, and detection of these and the maximum value is performed. The coordinate value xp of the input pen 10 is calculated by performing an operation corresponding to the equation (7) based on the coordinate value (known) of the loop coil immediately before the loop coil from which the voltage is obtained. it can.
[0118]
Thereafter, the control circuit 30 selects the loop coil (peak coil) from which the maximum detected voltage is obtained among the X direction loop coils 21-1 to 21-48 (or the Y direction loop coils 22-1 to 22-48). ) Is sent to the selection circuit 32 (or 33) (step S8), and transmission / reception of radio waves to / from the input pen 10 is repeated a plurality of times, for example, seven times, and output values obtained from the low-pass filters 43 and 44 are obtained. A / D conversion is performed (step S9), and the phase difference θ is calculated as described above (step S10).
[0119]
The obtained phase difference θ is adjusted by the control circuit 30 by, for example, adding 40 °, converted into phase information representing writing pressure, and the coordinates of the indicated position by the input pen 10 obtained in step S7. Together with the value, it is output to the electronic device 49 (step S11).
[0120]
When the first coordinate detection operation and the phase detection operation are completed by the processing shown in steps S1 to S11 described above, the control circuit 30 performs the X-direction loop coils 21-1 to 21 as the second and subsequent coordinate detection operations. -48, information about selecting only a certain number of, for example, 10 loop coils around the loop coil with the maximum detected voltage is sent to the selection circuit 32. Similarly, in the Y direction Out of the loop coils 22-1 to 22-48, centering on the loop coil where the maximum detection voltage is obtained, information for selecting only one constant, for example, 10 loop coils, is sent to the selection circuit 33. . Similarly, the output value is obtained, the coordinate detection operation and the phase detection operation in the X direction and the Y direction of the indicated position by the input pen 10 are performed, and the obtained coordinate value and phase information are transferred to the electronic device 49. These series of processes are repeated.
Thereby, the coordinate of the indication position by the input pen 10 and the information regarding the pen pressure at the time of operation can be acquired at any time.
[0121]
Next, the configuration of the input pen 10 used in the coordinate input device 1 as described above will be described in detail.
FIG. 7 is a diagram illustrating an example of the height of the protrusion 102 a formed on the ferrite chip 102 and a detection state in the coordinate input device 1, and (a) is detected by the load applied to the input pen 10 and the coordinate input device 1. It is a graph which shows the test result regarding the writing pressure which is, (b) is a figure which shows the conditions of the test shown to the figure (a).
[0122]
In addition, the test shown to Fig.7 (a) was done on the following conditions.
-As the ferrite core 104, L6 material (made by TDK) was used, and it was set as the structure of outer diameter (phi) 2.5mm (millimeter) and length 20mm.
The coil 105 has a 7-core, 46-turn configuration with a wire having a diameter of 0.07 mm.
The O-ring 103 is made of silicon rubber having a hardness of 30 degrees, and has an outer diameter of 2 mm, an inner diameter of 1 mm, and a linear shape of 0.5 mm.
-As the ferrite chip 102, an L6 material (manufactured by TDK) was used, and the configuration had an outer diameter of 2.5 mm and a length of 1 mm.
[0123]
In each test of (1) to (3) shown in FIG. 7A, the protrusion 102a shown in FIG. 7B has the following configuration. The height of the protrusion 102a is the height indicated by the symbol X in FIG. 7B, and the protrusion 102a has a circular cross section. The following values indicate values when the input pen 10 is not operated.
Condition (1): outer diameter φ0.8 mm, height 0.3 mm.
Condition (2): outer diameter φ0.8 mm, height 0.1 mm.
Condition (3): No protrusion 102a.
[0124]
In the graph shown in FIG. 7A, the horizontal axis represents the load applied to the input pen 10, and the vertical axis represents the writing pressure level detected by the coordinate input device 1.
The change in the pen pressure level detected by the tablet 20 is based on the change in the inductance of the coil 105 as described above. Therefore, the change in the vertical axis direction of the graph indirectly indicates the change in the inductance of the coil 105.
[0125]
As shown in FIG. 7A, under the condition of (3), that is, when the protrusion 102a is not present and the end face of the ferrite chip 102 is smooth, the coordinates are increased along with an increase in the load applied to the input pen 10. The writing pressure level detected by the input device 1 also rises gently.
[0126]
Further, under the condition (2), that is, when the protrusion 102a has a height of 0.1 mm, the writing pressure level rises more rapidly as the load increases than in the case shown in FIG. Standing up to.
[0127]
Furthermore, under the condition (1), that is, when the height of the protrusion 102a is 0.3 mm, the writing pressure level increases more rapidly as the load increases, and the graph rises very quickly. .
[0128]
In the graphs (1) and (2), when the load on the input pen 10 exceeds a predetermined value, the writing pressure level is substantially constant. This state is caused by the elastic deformation of the O-ring 103 and the protrusion 102a. And the ferrite core 104 are in contact with each other.
[0129]
As described above, from the result shown in FIG. 7A, the change in the writing pressure level with respect to the load applied to the input pen 10 is more sensitive as the protrusion 102a and the end face of the ferrite core 104 are closer to each other in the non-operation state. It can be said that there is. In addition, the presence or absence of the protrusion 102a greatly affects the response of the writing pressure level. Even when the height of the protrusion 102a is only 0.1 mm, a result clearly different from the case without the protrusion 102a is obtained. Further, when the height of the protrusion 102a is 0.3 mm, the difference is remarkable.
Therefore, if the protrusion 102a is provided on the end face of the ferrite chip 102 so that the ferrite chip 102 and the ferrite core 104 are close to each other in a non-operating state, the pen pressure detected even when the load on the input pen 10 is small. The level responds sharply and can detect a pressure level above a certain level. Thus, the input pen 10 that operates reliably even with a weak force and has good operability can be realized.
[0130]
In the first embodiment, the O-ring 103 is interposed between the ferrite chip 102 and the ferrite core 104 so that the ferrite chip 102 and the ferrite core 104 are disposed on the same axis, and the case 11 We are trying to make it thinner.
In this case, the ferrite chip 102 and the ferrite core 104 are separated from each other by the O-ring 103, but if the protrusion 102 a is formed on the ferrite chip 102 side and the protrusion 102 a is inserted into the center of the O-ring 103, The ferrite chip 102 and the ferrite core 104 can be brought closer to each other.
[0131]
Here, the test results when the height of the protrusion 102a of the ferrite chip 102 is further changed under the same conditions as the test shown in FIG.
FIG. 14 is a diagram showing another example of the height of the protrusion 102 a formed on the ferrite chip 102 and the detection state in the coordinate input device 1, and (a) shows the weight applied to the input pen 10 and the coordinate input device 1. It is a graph which shows the test result regarding the detected pen pressure, (b) is a figure which shows the conditions of the test shown to the figure (a).
[0132]
The graph shown in FIG. 14A shows an example in which only the height of the protrusion 102a is changed under the same conditions as the test shown in FIG. 7A. That is, as shown in FIG. 14B, the writing pressure level-load characteristic when the height of the protrusion 102a is 0.4 mm is shown as (4) in the figure.
As shown in FIG. 14A, when the height of the protrusion 102a is set to 0.4 mm, the writing pressure detected in response to the load is compared with the case where the protrusion 102a is 0.1 mm or 0.3 mm. The level rises quickly.
[0133]
If the writing pressure level rises quickly as shown in FIG. 14 (a), even if the load on the input pen 10 is small, the writing pressure level responds sharply and a writing pressure level above a certain level can be detected. . That is, even if the operator who operates the input pen 10 performs the operation with a light force, the operation can be reliably detected in the coordinate input device 1.
[0134]
Therefore, from the results shown in FIGS. 7A and 14A, the height of the protrusion 102a of the ferrite chip 102 is preferably 0.1 mm or more, more preferably 0.3 mm or more, An optimum value is 0.4 mm.
[0135]
Here, the characteristics of the magnetic material used for the ferrite chip 102 and the ferrite core 104 will be described.
As described above, in the tests shown in FIGS. 7A and 14A, the ferrite chip 102 and the ferrite core 104 are made of the L6 material (manufactured by TDK).
[0136]
However, since the ferrite chip 102 is a member close to the core 101 and is easy to apply force to the operator, it may be configured using a material having higher strength. For example, when the ferrite chip 102 is made of an L9G material (manufactured by TDK), the bending strength of the L6 material is 1.0E + 07 (kg / m), which is the strength of general nickel-based ferrite.²The bending strength of the L9G material is 1.8E + 07 (kg / m).²), The bending strength can be increased up to about 1.8 times.
Note that due to the difference in characteristics between the L6 material and the L9G material, the operation of the coordinate input device 1 may be affected when the L9G material is used instead of the L6 material. For example, when the ferrite core 104 is made of an L9G material, the change in inductance of the coil 105 may become dull. However, since the ferrite chip 102 is a minute member compared to the ferrite core 104, the influence when the ferrite chip 102 is made of the L9G material is very slight, and there is no problem in using the coordinate input device 1.
Therefore, it is very preferable that the ferrite chip 102 is made of L9G material (manufactured by TDK) and the ferrite core 104 is made of L6 material (manufactured by TDK) in terms of both characteristics and strength of the coil 105.
[0137]
Actually, a test for examining durability by applying a load to the core 101 of the input pen 10 configured using the L9G material (made by TDK) for the ferrite chip 102 and the L6 material (made by TDK) for the ferrite core 104. As a result, it was found that when a load of 300 g was applied at a frequency of 3 times / second, it could withstand a load of 10 million times or more.
[0138]
Further, it is possible to increase the durability of the ferrite core 104 by further increasing the diameter of the ferrite core 104. If the diameter of the ferrite core 104 is 2.5 mm or more, an impact is applied to the input pen 10. However, if it is 3.0 mm or more, higher durability can be obtained.
[0139]
FIG. 8 is a diagram illustrating a configuration example of the ferrite chip 102 and the ferrite core 104 in the input pen 10. FIG. 8A is a cross-sectional view illustrating the configuration example illustrated in FIG. 1, and FIG. (C) is a cross-sectional view showing a configuration example further different from FIGS. (A) and (b).
[0140]
As shown in FIG. 8A, the input pen 10 shown in FIG. 1 has a configuration in which a ferrite core 104 having a substantially smooth end face and a ferrite chip 102 having a protrusion 102a are opposed to each other.
However, the condition that the ferrite chip 102 and the ferrite core 104 are close to each other with the O-ring 103 interposed therebetween can be realized by other configurations.
[0141]
For example, as shown in FIG. 8B, a ferrite chip 601 having a substantially smooth end face may be used instead of the ferrite chip 102, and a ferrite core 602 having a protrusion 602a may be used instead of the ferrite core 104. The protrusion 602 a is a protrusion formed at the center of the end face similarly to the protrusion 102 a, and fits into the through-hole of the O-ring 103.
In this case, since the substantially smooth end face of the ferrite chip 601 and the protrusion 602a of the ferrite core 602 face each other through the O-ring 103, the same effect as the configuration shown in FIG. 8A can be obtained. Note that the protrusion 602a is formed at a height that does not come into contact with the opposing end face when the input pen 10 is not operated, like the protrusion 102a.
[0142]
Further, for example, as shown in FIG. 8C, a ferrite chip 603 having a protrusion 603a can be used instead of the ferrite chip 102, and a ferrite core 604 having a protrusion 604a can be used instead of the ferrite core 104. is there. The protrusions 603a and 604a are protrusions formed at the center of the end face similarly to the protrusion 102a, and fit into the through-hole of the O-ring 103. In this case, since the protrusion 603a included in the ferrite chip 603 and the protrusion 604a included in the ferrite core 604 are opposed to each other via the O-ring 103, the same effect as that of the configuration illustrated in FIG. The protrusions 603a and 604a are formed at a height that does not contact each other when the input pen 10 is not operated.
[0143]
FIG. 9 is a diagram showing another configuration example instead of the ferrite chip 102 and the ferrite core 104, (a) is a cross-sectional view showing a configuration using the ferrite chip 611 and the ferrite core 612, and (b) is a ferrite diagram. FIG. 6 is a cross-sectional view showing a configuration using a chip 614 and a ferrite core 615, and (c) is a cross-sectional view showing a configuration using a ferrite chip 616 and a ferrite core 617.
[0144]
Although FIGS. 8B and 8C show a configuration example in which a rod-like protrusion is formed at the approximate center of the end face, the present invention is not limited to this.
For example, as shown in FIG. 9A, a ferrite chip 611 having an outer peripheral projection 611 a on the outer edge of the end face is used instead of the ferrite chip 102, and the outer diameter is smaller than the O-ring 103 instead of the O-ring 103. Alternatively, an O-ring 613 that can be accommodated in the outer peripheral projection 611a may be used, and a ferrite core 612 having a substantially smooth end face may be used instead of the ferrite core 104.
[0145]
Here, as shown in FIG. 10A, the ferrite chip 611 is a substantially cylindrical member, and only the outer edge portion of the upper surface protrudes to form an outer peripheral protrusion 611a, and the inner side of the outer peripheral protrusion 611a is depressed. is doing. An O-ring 613 is accommodated in the outer peripheral projection 611a. Then, the thickness of the O-ring 613 and the height of the outer peripheral protrusion 611a are adjusted so that the outer peripheral protrusion 611a does not contact the end face of the ferrite core 612 when the input pen 10 is not operated as shown in FIG. If configured, the same effect as the input pen 10 shown in FIG. 1 can be obtained.
[0146]
Further, as shown in FIG. 9B, a ferrite core 615 having an outer peripheral protrusion 615a similar to the outer peripheral protrusion 611a is used in place of the ferrite core 104, and a ferrite chip having a substantially smooth end face instead of the ferrite chip 102 is used. A configuration using 614 is also possible. Then, as shown in FIG. 9B, if the outer peripheral projection 615a is configured not to contact the end face of the ferrite chip 614 when the input pen 10 is not operated, the same effect as the input pen 10 shown in FIG. can get.
[0147]
Further, as shown in FIG. 9C, a ferrite chip 616 having an outer peripheral protrusion 616a similar to the outer peripheral protrusion 611a is used in place of the ferrite chip 102, and a ferrite core 617 having an outer peripheral protrusion 617a similar to the outer peripheral protrusion 611a is used. It is also possible to adopt a configuration used instead of the ferrite core 104. In this case, as shown in FIG. 9C, if the outer peripheral protrusion 616a and the outer peripheral protrusion 617a are not in contact with each other when the input pen 10 is not operated, the same effect as the input pen 10 shown in FIG. It is done.
[0148]
Further, the outer peripheral protrusions 611a, 615a, 616a, and 617a may be configured to have notches 618a as in the ferrite chip 618 shown in FIG. 10 (b) as well as the configuration shown in FIG. 10 (a). In this case, the number and shape of the notches 618a are arbitrary.
[0149]
Further, for example, if the ferrite chip 611 and the ferrite core 612 shown in FIG. 9A are held on the same axis and do not shift laterally, a flexible ball is used instead of the O-ring 613. It is also possible.
That is, both the O-ring 103 shown in FIG. 1 and the O-ring 613 shown in FIG. 9A hold the ferrite chip and the ferrite core separately in a non-operating state of the input pen 10. A plurality of spheres may be used in place of the O-ring 613 as long as they are elastically deformed during the operation.
[0150]
11A and 11B are diagrams illustrating a configuration example of the protrusion 102a and the O-ring 103 included in the ferrite chip 102. FIG. 11A is a perspective view illustrating a configuration of the protrusion 102a, and FIG. It is a perspective view which shows the structural example different from FIG., (C) is a perspective view which shows the structural example further different from the figure (a) and (b). FIG. 9D is a perspective view showing the configuration of the O-ring 103 shown in FIG. 1, and FIG. 9E is a cross-sectional view. (F) is a perspective view which shows the structural example different from the figure (e), (g) is sectional drawing.
[0151]
The protrusion 102a of the ferrite chip 102 in the input pen 10 is a rod having a circular cross section as shown in FIG. 11 (a). For example, as shown in FIG. 11 (b), the protrusion 102a is formed as a protrusion 605a having a square cross section. May be.
When the ferrite chip 605 having the protrusion 605a is applied to the input pen 10 instead of the ferrite chip 102, the same effect as described above can be obtained if the protrusion 605a is fitted into the through-hole of the O-ring 103.
[0152]
Further, as shown in FIG. 11C, a ferrite chip 606 having a protrusion 606a having a triangular cross section may be used instead of the ferrite chip 102. In this case, if the projection 606a is fitted into the through hole of the O-ring 103, the same effect as described above can be obtained. Of course, in addition to the protrusions 605a and 606a, protrusions having different shapes can be used.
[0153]
Further, as shown in FIGS. 11D and 11E, the O-ring 103 in the input pen 10 is configured such that a wire having a circular cross section forms the letter “O”. The O-ring 103 has a circular cross-sectional shape and contacts the end surfaces of the ferrite chip 102 and the ferrite core 104 with a line. Therefore, when the input pen 10 is operated, when it is sandwiched between the ferrite chip 102 and the ferrite core 104 and elastically deformed, the input pen 10 can be deformed so as to spread in the horizontal direction along the end face of the ferrite core 104. That is, in the O-ring 103, the contact portion with respect to the ferrite chip 102 and the ferrite core 104 changes from a line state to a surface state, so that the O-ring 103 is easily elastically deformed when the input pen 10 is operated. Accordingly, when the input pen 10 is operated, the O-ring 103 is quickly deformed, and the ferrite chip 102 and the ferrite core 104 are brought close to each other. Therefore, the O-ring 103 shown in FIGS. It is suitable for.
[0154]
However, as shown in FIGS. 11 (f) and 11 (g), an O-ring 607 in which a wire having a square cross section is formed in the letter “O” may be used for the input pen 10 instead of the O-ring 103. Is possible. In this case, since the O-ring 607 is in surface contact with the ferrite chip 102 and the ferrite core 104, the O-ring 607 is relatively hardly elastically deformed. However, if the O-ring 607 is formed of a more flexible material, the same as the O-ring 103 is obtained. Operability is obtained. Further, when the input pen 10 is configured to be suitable for operation with a relatively strong force, the O-ring 607 that is less elastically deformed than the O-ring 103 is preferable.
[0155]
As described above, in the input pen 10, the ferrite core 104 is not formed with an opening or a hollow portion. Therefore, even if the ferrite core 104 is made thin, there is no risk of insufficient strength. Further, the core 101 and the ferrite chip 102 can be easily reduced in size, and each part can be accommodated in a very thin case 11 to make a small input pen 10. In addition, since the inductance of the coil 105 increases during operation, the input pen 10 can be operated in the same manner as a pen-type coordinate indicator that performs the same operation as a coordinate indicator using an expensive variable capacitor. In other words, the coordinate indicator used with the position detection device may employ an LC resonance circuit using a variable capacitor whose capacitance changes during pressurization in order to detect an operation. Such a coordinate indicator increases the capacity of the variable capacitor when an operation by the operator is applied, and as a result, the resonance frequency of the LC resonance circuit shifts to a lower side, and has a high sensitivity but a complicated structure. Yes and expensive. In the input pen 10, since the inductance of the coil 105 increases during operation, the resonance frequency of the tuning circuit 15 shifts to a lower side during operation. Therefore, a pen-type coordinate indicator that performs the same operation as a coordinate indicator using a variable capacitor can be realized at a low cost with a simpler configuration.
[0156]
Further, since the O-ring 103 is interposed between the ferrite chip 102 and the ferrite core 104, the restoration operation after the operation is performed smoothly, and good operability is obtained. Further, by obtaining the deformation amount of the O-ring 103 from the amount of change in the inductance of the coil 105, it is possible to obtain the force applied during the operation.
[0157]
Further, since the O-ring 103 is formed so as not to cover the entire end face of the ferrite chip 102 and the ferrite core 104, there is a portion where the ferrite chip 102 and the ferrite core 104 directly face each other. Since the inductance of the input pen 10 changes sharply and the operation is reliably detected, the response of the input pen 10 can be improved and good operability can be ensured.
[0158]
Also, by providing the protrusion 102a on the ferrite chip 102, the distance between the ferrite chip 102 and the ferrite core 104 in the initial state can be reduced, and the ferrite chip 102 and the ferrite core 104 can be brought close to each other quickly during operation. Further, since the height of the protrusion 102a is lower than the thickness of the O-ring 103, the structure for separating the ferrite chip 102 and the ferrite core 104 from each other when not operated may be sandwiched by an elastic body. Can be avoided.
[0159]
Furthermore, since the O-ring 103 is used as an elastic body between the ferrite chip 102 and the ferrite core 104, the ferrite chip 102 and the ferrite core 104 can be easily brought close to each other even when operated with a relatively weak force. For this reason, the input pen 10 has a small resistance during operation and can be operated with a relatively weak force.
[0160]
In the first embodiment, the ferrite chip 102 and the ferrite core 104 have been described as cylindrical. However, the present invention is not limited to this, and the ferrite core 104 winds the coil 105. The ferrite chip 102 may have any shape that can be fixed to the core 101. In addition to the configuration described above, the O-ring 103 can be replaced by attaching a flexible member such as a plurality of rectangular parallelepipeds to the ferrite chip 102, for example.
Further, the shape of the case 11 is not limited to a shape imitating a writing instrument, and any shape that can incorporate the ferrite chip 102, the O-ring 103, the ferrite core 104, the substrate holder 12, the substrate 13, the capacitor 14, the tuning circuit 15, etc. Needless to say, other detailed configurations can be variously modified within the scope of the technical idea described in the claims.
[0161]
In the first embodiment, the ferrite chip 102, the O-ring 103, and the ferrite core 104 are provided on the front end side of the case 11. However, the present invention is not limited to this, and the case 11 It may be provided on the rear end side. Hereinafter, this case will be described as a modification with reference to FIG.
[0162]
[Modification]
FIG. 12 is a cross-sectional view showing the configuration of the input pen 80 as a modified example of the first embodiment of the present invention.
In FIG. 12, 81 is a case, 82 is a substrate holder, 83 is a substrate, and 84 is a core. Moreover, about what is comprised similarly to the input pen 10 shown in FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0163]
As in the case 11, the input pen 80 shown in FIG. 12 accommodates each part in a small synthetic resin or metal case 81 formed by imitating a general writing instrument such as a ballpoint pen or a mechanical pencil. Composed.
A rod-shaped core 84 that is inserted into and out of the case 81 is disposed at the distal end of the case 81, and a base end portion of the core 84 is fixed to one end of the substrate holder 82.
A substrate 83 is fixed to the substrate holder 82, and various elements including the capacitor 14 are mounted on the substrate 83. The tuning circuit 15 includes the various elements mounted on the substrate 83, the capacitor 14, and the coil 105.
[0164]
A ferrite core 104 is fixed to the other end of the substrate holder 82, and the ferrite core 104 faces the ferrite chip 102 via the O-ring 103. The ferrite chip 102 is fixed to the inner surface of the case 81 at the base end portion of the case 81.
[0165]
Similar to the input pen 10, the input pen 80 is held on the substantially flat tablet 20 (FIG. 2) with the tip of the case 11 facing downward like a normal writing instrument, and the lead 84 is held in the tablet (FIG. 2). ).
[0166]
That is, the core 84 is pushed into the case 81 when the input pen 80 is operated. Then, since the substrate holder 82 is pressed together with the core 84, the ferrite core 104 fixed to the substrate holder 82 is pressed to the base end side of the case 81, that is, the ferrite chip 102 side. The O-ring 103 is elastically deformed by the pressing force applied via the ferrite core 104, and the ferrite core 104 and the protrusion 102a approach each other.
[0167]
Therefore, when the input pen 80 is operated, the protrusion 102a and the ferrite core 104 approach each other as in the operation of the input pen 10, and the inductance of the coil 105 changes. For this reason, if the input pen 80 is used instead of the input pen 10 and operated on the tablet 20, the coordinate position indicated by the operation of the input pen 80 can be detected by the coordinate input device 1.
[0168]
As described above, the input pen 10 according to the first embodiment is configured such that the ferrite chip 102 is provided on the core 101 side, so that the operation can be reliably performed even when the case 11 is operated in an inclined state, for example. The effect of responding is achieved, which is more preferable. However, except for this point, the same effect can be obtained even when the ferrite chip 102 is arranged on the base end side of the case 81 as in the input pen 80 shown in FIG. is there.
[0169]
[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 15 is a cross-sectional view showing the configuration of the input pen 70 in the second embodiment. Note that the material of each part constituting the input pen 70 shown in FIG. 15 is the same as that of each part of the input pen 10 in the first embodiment.
[0170]
An input pen 70 shown in FIG. 15 is a pen-type coordinate indicator that is operated by an operator for the purpose of indicating coordinates in the coordinate input device 1 in the same manner as the input pen 10.
The input pen 70 includes a hollow case 701 having a rear opening, a cap 702 that is fitted in the rear opening of the case 701 to close the opening, a substrate holder 703 that is accommodated in the hollow portion of the case 701, and a substrate holder 703. A substrate 704 to be fixed, a capacitor 705 mounted on the substrate 704, a tuning circuit 706 including the capacitor 705, a ferrite core 708 disposed in contact with the substrate holder 703, and wound around the ferrite core 708 A coil 709, a ferrite chip 710 disposed so as to face the front end surface of the ferrite core 708 via an O-ring 711, and a core that is disposed in contact with the ferrite chip 710 and has a front end protruding outward from the front end of the case 701 712 and the like.
Further, in the input pen 70, a buffer member 707 is interposed between the base end portion of the substrate holder 703 and the cap 702.
In the following description, for each part of the input pen 70, the distal end side of the case 701 is referred to as a “front end portion”, and the rear side of the case 701 is referred to as a “base end portion”.
[0171]
In addition, each part of the board | substrate 704, the capacitor | condenser 705, the tuning circuit 706, and the coil 709 is comprised similarly to the board | substrate 13, the capacitor | condenser 14, the tuning circuit 15, and the coil 105 in the said 1st Embodiment, and has an equivalent function Therefore, the description is omitted here.
[0172]
A case 701 is open at the tip of the input pen 70, and the tip of the case 701 protrudes from this opening. The case 701 includes a disc-shaped base end portion and a rod-like portion standing on the base end portion, and the base end portion is in contact with the ferrite chip 710. The ferrite chip 710 faces the ferrite core 708 with the O-ring 711 interposed therebetween. The ferrite chip 710 has a protrusion similar to the protrusion 102a of the ferrite chip 102 in the first embodiment.
Further, the ferrite core 708 is disposed so as to be sandwiched between the ferrite chip 710 and the substrate holder 703, and the base end portion of the substrate holder 703 is in contact with the cap 702 via the buffer member 707. The core 712, the ferrite chip 710, the O-ring 711, the ferrite core 708, the substrate holder 703, the cap 702, and the case 701 are arranged on the same axis. The buffer member 707 is made of an elastic material such as urethane foam or rubber.
[0173]
Here, the configuration of the tip of the input pen 70 will be described in detail.
FIG. 16 is an enlarged view showing a main part of the input pen 70 in an enlarged manner. As shown in FIG. 16, the inner diameter of the hollow portion provided inside the case 701 becomes narrower in three steps toward the distal end portion of the input pen 70, and reference sign A in the drawing sequentially from the proximal end portion side of the input pen 70. , B, and C are formed. Among these, each part such as the substrate holder 703 is accommodated in the hollow part of the case 701 between the step A and the base end part of the case 701.
The distal end of the ferrite core 708 is in contact with the step B, and the proximal end portion is in contact with the distal end of the substrate holder 703. Further, the base end portion of the core 712 is in contact with the stepped portion C, and the base end portion of the core 712, the ferrite chip 710, and the O-ring 711 are accommodated between the stepped portion C and the stepped portion B. .
[0174]
A core holding projection 721 that protrudes toward the tip side of the case 701 is formed at the tip of the substrate holder 703. The core holding projection 721 is fitted with a hole formed on the ferrite holder 708 on the substrate holder 703 side. Match. Thereby, the ferrite core 708 and the substrate holder 703 are fixed so as not to be displaced in the cross-sectional direction of the input pen 70.
[0175]
Further, a chip holding projection 722 that protrudes toward the base end side of the case 701 is formed on the disc-shaped portion of the base end portion of the core 712, and the chip holding projection 722 is formed on the core 712 side of the ferrite chip 710. Mates with the provided hole. Thereby, the ferrite chip 710 and the core 712 are fixed so as not to be displaced in the cross-sectional direction of the input pen 70.
[0176]
In the input pen 70 configured as described above, the substrate holder 703 and the ferrite core 708 housed in the hollow portion of the case 701 are fixed at the distal end side by the stepped portion B, and the proximal end portion side through the buffer member 707. The cap 702 is fixed. For this reason, the substrate holder 703 and the ferrite core 708 are fixed by the elastic force of the buffer member 707.
Further, the ferrite chip 710 and the core 712 are fixed at the distal end side by a stepped portion C, and the proximal end side is fixed by a ferrite core 708 via an O-ring 711. For this reason, the ferrite chip 710 and the core 712 can move to the base end side of the input pen 70 within a range in which the O-ring 711 can be bent.
[0177]
When the input pen 70 is operated, the tip of the input pen 70 is pressed against the surface of the tablet 20 (FIG. 2), so that the lead 712 is pushed into the inside of the case 701. Move to the club side. Thereby, the operation of the input pen 70 can be detected by the coordinate input device 1 when the inductance of the coil 709 wound around the ferrite core 708 changes.
[0178]
In the input pen 70, the substrate holder 703 and the ferrite core 708 are fixed by the elastic force of the buffer member 707, and the ferrite chip 710 and the core 712 are sandwiched between the step C and the O-ring 711. Therefore, when the input pen 70 is not operated, the core 712 does not fall out of the case 701, and the ferrite core 708 and the core 712 do not move freely. It can be.
[0179]
Further, since the substrate holder 703 and the ferrite core 708 are fixed by the core holding projection 721, and the core 712 and the ferrite chip 710 are fixed by the chip holding projection 722, the substrate holder 703 and the ferrite core 708 or the core 712 and the ferrite are fixed. There is no need to bond the chip 710. Generally, when an adhesive is used for a resin having durability during sliding, it is difficult to obtain a strong adhesive force. According to the input pen 70, since the core 712 and the substrate holder 703 can be fixed without using an adhesive, the input pen 70 having excellent durability can be realized, and the man-hours and work load at the time of manufacturing can be reduced. By doing so, it can be easily manufactured at low cost.
[0180]
Furthermore, due to tolerances in manufacturing the ferrite core 708, the size of the ferrite core 708 in the longitudinal direction may deviate from the designed size. In the input pen 70, even if the longitudinal size of the ferrite core 708 differs depending on the tolerance, the tolerance can be absorbed by the elasticity of the buffer member 707. Thereby, the man-hours and work load at the time of manufacture are further reduced, and it can manufacture easily at further low cost.
[0181]
In addition, when an impact is applied to the input pen 70, the shock can be absorbed by the buffer member 707 together with the O-ring 711. Therefore, the input pen 70 having higher durability can be realized, and good operability is maintained for a long time. Can keep. And since it is excellent in durability, the input pen 70 can also be comprised further thinly.
[0182]
In the second embodiment, when the longitudinal shift due to the manufacturing tolerance of the ferrite core 708 is obvious, the tolerance can be corrected using a resin piece or the like formed in a ring shape.
FIG. 17 is an enlarged cross-sectional view showing the main part of the input pen 70 as in FIG.
[0183]
As described above, the distal end portion of the substrate holder 703 and the proximal end portion of the ferrite core 708 are fixed by the core holding protrusion 721. Therefore, the ring-shaped film 723 formed in a ring shape is mounted so as to be fitted into the core holding protrusion 721, and the ring-shaped film 723 is interposed between the substrate holder 703 and the ferrite core 708. .
The ring type film 723 is a film made of a resin such as PET (polyethylene terephthalate), and the thickness thereof is, for example, 0.1 mm. The ring film 723 has a hole in the center, and the diameter of the hole is approximately the same as or larger than the outer diameter of the core holding projection 721.
[0184]
For example, when it is clear that the length in the longitudinal direction of the ferrite core 708 is 0.3 mm shorter than the designed size, by inserting three ring-shaped films 723 each having a thickness of 0.1 mm into the core holding protrusion 721, the substrate holder 703 and the ferrite core 708 are separated by 0.3 mm. Thereby, the input pen 70 can be assembled similarly to the case where the ferrite core 708 is formed according to the designed size.
[0185]
Similarly, by attaching a film similar to the ring-type film 723 so as to be fitted into the chip holding protrusion 722, the shift is not caused when the longitudinal size of the ferrite chip 710 is deviated from the designed size. It becomes possible to correct.
[0186]
Further, since the ring type film 723 is provided for the purpose of correcting the tolerance of the ferrite core 708 and fixing the substrate holder 703 and the ferrite core 708, the substrate is formed only by the buffer member 707 without using the ring type film 723. It is also possible to fix the holder 703 and the ferrite core 708. However, when the input pen 70 is provided with a switch, it is preferable to use the ring type film 723.
Hereinafter, a case where the input pen 70 is provided with a switch will be described.
[0187]
18 is a cross-sectional view showing a configuration of an input pen 71 in which a switch 73 is provided on the input pen 70 shown in FIG.
In addition, in the input pen 71, about the part which consists of the same structure as the input pen 70, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0188]
As shown by a broken line in FIG. 18, a switch 73 that is pressed by an operator is provided on the side surface of the input pen 71. The switch 73 is a switch assembled to the exterior of the case 701, and a detection unit (not shown) for detecting a pressing operation of the switch 73 is provided on the substrate 704.
Since both the case 701 and the switch 73 are made of synthetic resin or the like, manufacturing tolerances are negligible, and the position of the switch 73 in the case 701 is substantially constant.
[0189]
Here, if the tolerance in manufacturing the ferrite core 708 is to be absorbed by the elasticity of the buffer member 707, the position of the substrate holder 703, that is, the position of the substrate 704 moves along the axial direction of the input pen 71. . If the substrate 704 moves, the position of the switch 73 and the position of a detection unit (not shown) that detects the pressing operation of the switch 73 may be shifted, which is not preferable.
On the other hand, if the manufacturing tolerance of the ferrite core 708 is absorbed by the ring film 723, the position of the substrate holder 703, that is, the position of the substrate 704 is constant regardless of the size of the ferrite core 708. For this reason, there is no possibility that the position of the switch 73 and the position of the detection unit (not shown) for detecting the pressing operation of the switch 73 are shifted.
[0190]
The ring-shaped member interposed between the substrate holder 703 and the ferrite core 708 is not limited to the ring-type film 723 and may be any member having a predetermined elasticity and a size corresponding to the tolerance of the ferrite core 708. It is possible to obtain the same effect by using a so-called O-ring. For example, when the O-ring is configured to have a wire diameter of 0.4 mm, an outer diameter of 2.2 mm, and an inner diameter of 1.4 mm, it is preferable in view of the size of the input pen 71, but the outer diameter and inner diameter are the sizes of the input pen 71. The wire diameter may be changed depending on the tolerance of the ferrite core 708. As a material of the O-ring, for example, NBR (nitrile rubber) having a hardness of 70 is suitable.
In order to absorb the tolerance of 0.4 mm as the tolerance of the ferrite core 708, when the ring-type film 723 having a thickness of 0.1 mm is used, four ring-type films 723 are overlapped, but the wire diameter is 0.4 mm. If an O-ring is used, only one component is required. For this reason, when the tolerance of the ferrite core 708 does not fall within a fine value, the O-ring is fitted so as to be fitted into the core holding protrusion 721, and the tolerance of the ferrite core 708 is absorbed to complicate the work process. Tolerances can be corrected without fail.
[0191]
Note that the configuration of the input pens 70 and 71 in the second embodiment described above is only a preferable example, and is configured by omitting the buffer member 707 instead of using the ring-type film 723 or the O-ring, for example. In addition, specific details such as materials constituting each part can be arbitrarily changed without departing from the gist of the present invention.
[0192]
【The invention's effect】
As described above, according to the first aspect of the present invention, since it is not necessary to provide an opening on the end surface of the core, it is possible to realize a very thin pen-type coordinate indicator by forming the core thinly. it can. In addition, since the inductance of the coil increases during operation and the resonance frequency of the LC resonance circuit including the coil shifts to a lower side, a pen-type coordinate indicator that performs the same operation as a coordinate indicator using a variable capacitor is provided. It can be realized at a low cost with a simpler configuration.
[0193]
  Also,Since the restoring operation after the operation is smoothly performed by the elastic body, a pen-type coordinate indicator with good operability can be realized with a simple configuration. It is also possible to determine the amount of deformation of the elastic body from the amount of change in coil inductance and to determine the force applied during operation.
[0194]
  further,The coil inductance changes significantly during operation, and when a large force is applied compared to the elasticity of the elastic body, the core and magnetic body are very close to or in contact with each other, and the coil inductance changes more greatly. Therefore, it is possible to realize a pen-type coordinate indicator with good response and good operability.
[0195]
  AlsoBy reducing the distance between the elastic body and the core in the initial state and quickly bringing the core and the magnetic body close to each other during operation, it is possible to realize a pen-type coordinate indicator with good response and good operability. Further, as a configuration for separating the core and the magnetic body from each other when not operated, it is only necessary to sandwich the elastic body, so that the structure is not complicated.
[0197]
  Claim 1According to the described invention, it is possible to realize a pen-type coordinate indicator that has low resistance during operation and can be operated with a relatively weak force. In addition, the elastic body is supported by the protruding portion to prevent the relative position of the core, the magnetic body, and the elastic body from shifting, and a pen-type coordinate indicator with higher reliability can be realized. Furthermore, alignment when arranging an elastic body between the core and the magnetic body is easy.
[0198]
  According to the invention of claim 2,Even if the magnetic body moves reliably in response to the operator's operation and the force due to the operation is difficult to be transmitted, for example, when the operator tilts the case and operates it, A pen type coordinate indicator that responds and has good operability can be realized. Further, by thinning the core, the case can be made thinner and the operability can be improved.
[0199]
  Claim 3According to the described invention, since the core is supported by the step so as not to move outward from the hollow portion of the case, the core does not move during use of the pen-type coordinate indicator of the present invention, A stable operation feeling can be realized. Further, it is not necessary to use a technique such as adhesion to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0200]
  Claim 4According to the described invention, the core can be supported by the elasticity of the second elastic body, and even if there is a tolerance in the size of the core in the longitudinal direction, this tolerance is reduced by the second elastic body. It can be absorbed by elasticity, can support the core reliably regardless of the tolerance of the core, and can realize a stable operation feeling. Further, the pen-type coordinate indicator to which the present invention is applied does not need to correct the core tolerance, and can be easily manufactured with a small number of man-hours.
[0201]
  Claim 5According to the described invention, the core holding projection and the concave portion of the core are fitted, and the core is supported by the second elastic body and the support member, so that the core can be reliably supported. As a result, the core does not move during use of the pen-type coordinate indicator of the present invention, and a stable operation feeling without rattling can be realized. Further, it is not necessary to use a technique such as adhesion to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0203]
  Claim 6According to the described invention, the secondStepSince the core is held so as not to move to the outside of the case, it is possible to realize a stable operation feeling without rattling. Further, it is not necessary to use a technique such as bonding the core and a magnetic material to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[0204]
  Claim 7According to the described invention, since the magnetic body holding projection and the concave portion of the magnetic body are fitted together, the magnetic body and the core are supported integrally with each other. Therefore, it is possible to realize a stable operation feeling without rattling. Further, it is not necessary to use a technique such as bonding the core and a magnetic material to fix the core, and the pen-type coordinate indicator to which the present invention is applied can be easily manufactured with a small number of man-hours.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an input pen 10 according to a first embodiment of the present invention.
2 is a circuit diagram showing a configuration of a coordinate input device 1 including the input pen 10 of FIG.
3 is an exploded perspective view showing a configuration of a main part of the tablet 20 of FIG. 2, and specifically shows an arrangement state of an X-direction loop coil group 21 and a Y-direction loop coil group 22 constituting the tablet 20. FIG. FIG.
4 is a timing chart showing each signal in the coordinate input device 1 of FIG. 2; FIG.
FIG. 5 is a flowchart showing the operation of the control circuit 30 of FIG.
6 is a timing chart showing a signal detection operation in the tablet 20 of FIG. 2, wherein (a) shows a sine wave signal sent to the loop coil of the tablet 20, and (b) shows switching between a transmission period and a reception period. A state is shown, (c) shows the detection voltage in the loop coil of the tablet 20. FIG.
7 is a diagram showing the relationship between the height of the protrusion 102a formed on the ferrite chip 102 of FIG. 1 and the detection state in the coordinate input device 1 shown in FIG. 2, where (a) shows the load applied to the input pen 10. FIG. The graph of the test result regarding the writing pressure detected with the coordinate input device 1 is shown, (b) is a figure which shows the test conditions of the figure (a).
8 is a cross-sectional view showing a configuration example of a ferrite chip 102 and a ferrite core 104 in the input pen 10 of FIG. 1, in which (a) shows the configuration example shown in FIG. 1, and (b) shows a ferrite chip 601 and A configuration example using the ferrite core 602 is shown, and (c) shows a configuration example using the ferrite chip 603 and the ferrite core 604.
9 is a diagram showing a configuration example instead of the ferrite chip 102 and the ferrite core 104 in FIG. 1. FIG. 9A is a cross-sectional view showing a configuration using the ferrite chip 611 and the ferrite core 612, and FIG. 2 is a cross-sectional view showing a configuration using a ferrite chip 614 and a ferrite core 615, and FIG. 2C is a cross-sectional view showing a configuration using a ferrite chip 616 and a ferrite core 617. FIG.
10A and 10B are diagrams showing a configuration example instead of the ferrite chip 102 in FIG. 1, wherein FIG. 10A is a perspective view showing a configuration of a ferrite chip 611, and FIG. 10B is further different from FIG. It is a perspective view which shows the ferrite chip | tip 618 as a structural example.
11 is a diagram illustrating a configuration example of the protrusion 102a of the ferrite chip 102 and the O-ring 103 included in the input pen 10 of FIG. 1, and FIG. 11A is a perspective view illustrating a configuration of the protrusion 102a illustrated in FIG. (B) is a perspective view showing the configuration of the ferrite chip 605, and (c) is a perspective view showing the configuration of the ferrite chip 606. FIG. 9D is a perspective view showing the configuration of the O-ring 103, and FIG. 9E is a cross-sectional view showing the configuration of the O-ring 103. (F) is a perspective view showing the configuration of the O-ring 607, and (g) is a cross-sectional view showing the configuration of the O-ring 607.
FIG. 12 is a cross-sectional view showing a configuration of an input pen 80 as a modification of the first embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a configuration of an input pen 90 as an example of an input pen in a conventional pen tablet.
14 is a diagram showing another example of the height of the protrusion 102a formed on the ferrite chip 102 of FIG. 1 and a detection state in the coordinate input device 1, and FIG. It is a graph which shows the test result regarding the writing pressure detected by the apparatus 1, (b) is a figure which shows the conditions of the test shown to the figure (a).
FIG. 15 is a cross-sectional view showing a configuration of an input pen 70 according to a second embodiment of the present invention.
16 is an enlarged view of a main part showing a tip portion of the input pen 70 shown in FIG.
17 is an enlarged view of a main part showing a distal end portion of the input pen 70 shown in FIG.
FIG. 18 is a cross-sectional view showing a configuration of an input pen 71 in which a switch 73 is provided in the input pen 70 according to the second embodiment of the present invention.
[Explanation of symbols]
1 Coordinate input device
10, 70, 71 Input pen
11,701 cases
12,703 Substrate holder
13,704 substrate
14,705 capacitor
15,706 tuning circuit
101,712 core
102,710 Ferrite chip
102a protrusion
103,711 O-ring
104,708 ferrite core
105,709 coil
707 cushioning member
721 Core holding protrusion
722 Tip holding protrusion
723 Ring-type film
73 switch
A, B, C Step
20 tablets

Claims (7)

A pen-type coordinate indicator that indicates a position to be measured to a position detection device that measures a position and notifies an operator's operation,
A coil wound around a cylindrical core having an end face without an opening;
A cylindrical magnetic body disposed opposite to the end surface of the core, which is separated from the core and approaches in accordance with the operation of the operator along the axis of the coil ,
An elastic body interposed between an end surface of the core and the magnetic body,
The elastic body is an annular member having a through hole communicating with an end face of the core and a facing face of the magnetic body, and is in contact with only a part of the end face of the core, and the magnetic body In the facing surface that faces the end face of the core of the surface, only a part of the facing surface is in contact,
A protrusion is formed on one or both of a part of the end face of the core and a part of the opposing surface of the magnetic body facing each other without the elastic body, and the protrusion is The pen-type coordinate indicator characterized by having a side surface along the inner side surface of the elastic body, and the height of the protruding portion being smaller than the thickness of the elastic body. The core and the magnetic body are housed in a pen-type case, and a lead that is inserted into and out of the case is disposed at the tip of the case, and the magnetic body is connected to a base end portion of the lead. The pen-type coordinate indicator according to claim 1. The hollow portion of the case that accommodates the core and the magnetic body is formed with a step portion in which the inner diameter of the hollow portion is narrowed on the distal end side of the case, and the end surface of the core that faces the magnetic body is hollow. The pen-type coordinate indicator according to claim 2 , wherein the pen-type coordinate indicator is disposed so as to abut on a step portion formed in the portion .   The second elastic body is provided between the end surface of the core not facing the magnetic body and a base end portion of the hollow portion of the case. Pen-type coordinate indicator. The core further includes a support member interposed between an end surface of the core not facing the magnetic body and the second elastic body, and the support member protrudes toward the end surface of the core. 5. The pen-type coordinate indicator according to claim 4, wherein the pen-type coordinate indicator is provided with a protrusion, and an end surface of the core in contact with the support member is formed with a recess that fits into the core holding protrusion. In the hollow portion of the case that accommodates the core and the magnetic body, a second step portion in which the inner diameter of the hollow portion is further narrowed is formed on the distal end side of the case. flat portion parallel to the cross section of the case is formed, the core is characterized in the that the flat portion is arranged to be in contact with the second stepped portion formed in the hollow portion of the case according Item 6. The pen-type coordinate indicator according to any one of Items 2 to 5 . The flat portion formed at the base end portion of the core is further formed with a magnetic body holding projection that protrudes toward the end surface of the magnetic body, and the end surface of the magnetic body that is in contact with the core has the magnetic body holding portion. The pen-type coordinate indicator according to claim 6, wherein a concave portion that fits into the protrusion is formed.

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