JP5455426B2 - Input medium for position detection input device and position detection input device - Google Patents

Description

  The present invention relates to an input medium of a position detection input device in a small-sized input device such as a mobile phone or a PDA, and more particularly to a position detection input device that calculates the position of an input medium from a magnetic field strength value using a magnetic sensor. It relates to the input medium.

  Conventionally, there has been an invention of Patent Document 1 as a three-dimensional position detection input device that detects a position of an input medium in a three-dimensional space with a magnetic sensor.

  In the position detection input device according to the present invention, a magnetic field is formed around the magnet, the magnetic field is detected by the detection means, and the position of the magnet is determined as a position of the input medium based on the strength and direction of the magnetic field from the detection signal. It seeks the right position.

JP-A-8-272528

  However, although the relationship between the magnetic field strength value and the distance from the magnetic sensor to the magnet is shown in the three-dimensional position detection input device, the influence of the direction of the magnetic field is not described. However, since the tilt of the input medium such as a pen varies somewhat depending on the input person's eyelid, the magnetic field strength value is measured differently even though it is at the same position due to the tilt difference, and the position of the input medium is There was a problem of changing depending on the input person.

  Therefore, the present inventors invented an input medium for a position detection input device having a feature that the direction of the magnetic field of the magnet does not change even when the inclination of the input medium changes, and solved this problem.

  That is, the present invention is an input medium in which a space for placing a magnet is formed, and the magnet can freely move in the space. When the input medium is tilted, the magnet moves in response to the input medium. This is an input medium for a position detection input device having a feature that the direction of the magnetic field of the magnet does not change even when the inclination of the input medium changes.

  Further, the present invention may be an input medium for a position detection input device, wherein the magnet is formed in any one of a spherical shape, an elliptical spherical shape, a hemispherical shape, and a semi-elliptical spherical shape with a center of gravity biased downward. . The present invention may also be an input medium for a position detection input device, wherein the magnet is placed with a fixed point in the space as a fulcrum, and the center of gravity of the magnet is below the fulcrum. .

  The present invention is also a position detection input device comprising at least the input medium for the position detection input device described above and a magnetic sensor for detecting the strength of the magnetic field generated from the magnet of the input medium for the position detection input device. .

  An input medium for a position detection input device according to the present invention is an input medium in which a space for placing a magnet is formed, and the magnet can freely move in the space. Even if the magnet moves and the inclination of the input medium changes, the magnetic field direction of the magnet does not change. Accordingly, the inclination of the input medium is changed by the input person's habit, and there is an effect of preventing the magnetic field strength value from being measured differently due to the difference in the inclination.

  The input medium for a position detection input device according to the present invention is characterized in that the magnet has one of a spherical shape, an elliptical spherical shape, a hemispherical shape, and a semi-elliptical spherical shape with a center of gravity biased to the lower portion. Alternatively, the magnet is placed with a fixed point in the space as a fulcrum, and the center of gravity of the magnet is below the fixed point. Therefore, there is an effect that even if the input medium is tilted, the magnet moves in accordance with it and the direction of the magnetic field of the magnet does not change.

  The position detection input device of the present invention includes at least the position detection input device input medium described above and a magnetic sensor for detecting the strength of a magnetic field generated from the magnet of the position detection input device input medium. Therefore, there is an effect that the position of the input medium can be determined only by the distance and direction between the magnet and the magnetic sensor.

It is a schematic cross section which shows one Example of the input medium for position detection input devices which concerns on this invention. It is a schematic diagram which shows the enlarged view of the input medium for position detection input devices, (a) shows the case where the input medium for position detection input devices stands upright, (b) is the input medium for position detection input devices It is a schematic diagram in the case of the state which inclined diagonally. It is a schematic diagram which shows the enlarged view of the input medium for position detection input devices, (a) shows the case where the input medium for position detection input devices stands upright, (b) is the input medium for position detection input devices It is a schematic diagram in the case of the state which inclined diagonally. It is a schematic diagram which shows the example of the shape of the magnet of the input medium for position detection input devices. It is a schematic diagram which shows the example of the shape of the magnet of the input medium for position detection input devices. It is a schematic diagram which shows the position detection input device using the input medium for position detection input devices of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  The position detection input device input medium 10 has a space 14 in which the magnet 12 is placed, and is configured so that the magnet 12 can freely move in the space 14. It has a structure like a touch pen with a built-in (see FIG. 1). However, the position detection input device input medium 10 is not limited to this form, and may be any form as long as it can generate an appropriate magnetic field.

  If the magnet 12 is fixed to the position detection input device input medium 10, if the position detection input device input medium 10 is tilted, the magnet 12 is tilted accordingly, so that the direction of the magnetic field generated from the magnet 12 changes. Accordingly, the direction and strength of the magnetic field also change, so that the position of the magnet 12 cannot be accurately detected by the magnetic sensor 16. In the present invention, a space 14 larger than the magnet 12 is formed inside so that the magnet 12 can move freely without being fixed, and this problem is solved by placing the magnet 12 in the space 14 ( (See FIG. 2).

  Examples of the magnet 12 include a neodymium magnet, a neodymium magnet, a Samacoba magnet, a ferrite magnet, and an alnico magnet. Examples of the method for manufacturing the magnet 12 include a magnetic field forming / sintering method and a melt spinning method. Among these, Nd—B—Fe-based neodymium sintered magnets are suitable because they have a high energy product.

  The magnet 12 has a spherical shape, an elliptical spherical shape, a hemispherical shape, or a semi-elliptical spherical shape with a center of gravity 18 biased in the lower portion (see FIG. 4), or the magnet 12 has a fixed point 30 in the space 14 as a fulcrum. The center of gravity 18 of the magnet 12 is preferably located below the fixed point 30. In addition, the method of mounting the magnet 12 with the fixed point 30 as a fulcrum is not only a method of projecting and supporting like a needle from the lower direction (see FIG. 3), but also a method of supporting by suspending from the upper direction or the lateral direction (see FIG. 5). Is mentioned.

  With such a shape or form in which the center of gravity 18 is at the bottom, even if the position detection input device input medium 10 is tilted, the gravity due to the weight of the magnet 12 and the drag from the position detection input device input medium 10 (or a fixed point 30). The resultant force with the centripetal force from the second position acts in a direction to return to the state before the input medium 10 for the position detection input device is tilted, and the magnet 12 moves to the state before the tilt. As a result, the magnet 12 returns to the state before the tilt. Therefore, even if the inclination of the input medium 10 for the detection input device changes, the direction of the magnetic field of the magnet 12 can be prevented from changing (see FIGS. 2 and 3).

  As a result, when the position detection input device input medium 10 and the magnetic sensor 16 that detects the strength of the magnetic field generated from the magnet 12 are used, the position of the position detection input device input medium 10 is magnetized with the magnet 12. A position detection input device 20 that can be determined only by the distance and direction of the sensor 16 can be obtained.

  The obtained position detection input device 20 is configured such that when the magnetic sensor 16 is positioned on the outer frame portion of the position information display unit 3 having a window shape at the center, and the position detection input device input medium 10 approaches, the built-in magnet The magnetic sensor 16 detects the strength and direction of the magnetic field generated from the signal 12, and the signal is instantaneously sent to the calculation unit 25. The calculation unit 25 generates a magnetic field from the strength and direction of the magnetic field that is the signal. The position is calculated instantaneously and the position of the position detection input device input medium 10 can be determined three-dimensionally (see FIG. 6).

  That is, when the distance between the magnetic sensor 16 and the position detection input device input medium 10 reaches a certain distance, the strength and direction of the magnetic field of the built-in magnet 12 are detected, and the distance is the strength of the magnetic field. Therefore, the distance between the magnetic sensor 16 and the magnet 12 can be calculated from the value of the magnetic field strength, and the position of the input medium 10 can be determined three-dimensionally from the direction of the detected magnetic field. It is a mechanism that can be decided on.

  Examples of the magnetic sensor 16 include a small and space-saving MR element (magnetoresistance effect element), a Hall element, and a magnetic detection element utilizing the magnetic impedance effect. Among these, a magnetic detection element using the magneto-impedance effect is most preferable because of its high detection sensitivity and wide detection range. The magneto-impedance effect is a phenomenon in which when a high-frequency current in the MHz band is passed through a magnetic material, the impedance between both ends of the magnetic material changes due to an external magnetic field, and the amplitude of the voltage between both ends changes. Even with a strong external magnetic field, there is a characteristic that changes by several tens of percent.

  The magnetic sensor 16 is preferably a magnetic sensor including a detection range of 0.2 to 50 Gauss. If the magnetic sensor includes the entire detection range, even if the lower limit of the detection range is not lower than 0.2 gauss (that is, the detection range is not wider than this), a magnet 12 that generates a high magnetic force can be selected. This is because position detection is sufficiently possible at any input position. Conversely, in the case of a magnetic sensor that has a low detection lower limit (that is, even a highly sensitive magnetic sensor) and does not include the above detection range (that is, the upper limit is less than 0.2 gauss), do not use a magnetic shield. This is because noise may be generated due to the strength of the geomagnetic field (about 0.5 gauss) and position detection may not be possible.

  The set positions of the magnetic sensor 16 may be provided with a total of two on the opposite sides of the outer frame portion of the magnetic sensor module 5 or four in the vicinity of the center of each side at equal distance intervals.

  6 shows the case where the position information display screen 3 has a rectangular shape, the position information display screen 3 may be a square, an ellipse, a rhombus, or the like, and is not particularly limited. In these cases, as in the case of the rectangular shape, it is the most preferable aspect that the magnetic sensors 16 are arranged at equal intervals around the periphery. A decorative layer for concealing the magnetic sensor 16 may be formed on the upper outer frame portion or the lower outer frame portion of the position information display screen 3.

(1) Production of neodymium-based sintered magnet A powder blended in a weight ratio of Nd (neodymium) 28%, B (boron) 2%, Fe (electrolytic iron) 69%, Dy (dysprosium) 2% is 1300 ° C. Melted at a high temperature, rapidly cooled, pulverized into particles having an average particle diameter of 5 μm with a nitrogen gas in a jet mill, placed in a magnetic press, and molded in a nitrogen atmosphere at a magnetic field strength of 20 kOe and a molding density of 5 g / cc. . Then, after putting in a heat treatment furnace in a vacuum atmosphere and sintering at 1100 ° C. and aging treatment at 700 ° C., it was processed into a hemisphere having a diameter of 2 mm with a center of gravity biased to the bottom by cutting and grinding. Next, after nickel and copper were plated on the surface, a magnetizing process with a maximum magnetic field strength of 50 kOe was performed with a pulse magnetizer to obtain a neodymium sintered magnet. The obtained neodymium sintered magnet had an N-pole cross section and an S-pole at the top of the spherical surface.

(2) Production of input medium for position detection input device A spherical space having a diameter of 2.5 mm is produced in the vicinity of the tip of a pencil-shaped molded product having a length of 10 cm and a diameter of 5 mm, and the diameter is within the space. A 2 mm hemispherical neodymium sintered magnet was placed to obtain an input medium for a position detection input device. Whether the obtained input medium for the position detection input device is vertical or inclined at 45 degrees, the neodymium-based sintered magnet is free to have the S pole at the bottom of the spherical space with its own weight. It was something to move on. As a result, the direction of the magnetic field did not change at all, whether it was vertical or inclined 45 degrees.

(3) Production and evaluation of position detection input device A calculation unit including calculation means for calculating the position of the input medium from the value of the magnetic field strength of the magnetic sensor is prepared, and the calculation unit and the magnetic sensor are Connect the signal detected by the magnetic sensor to the calculation unit instantly, set the calculation unit in the calculation unit so that the strength of the magnetic field and the position where the magnetic field was generated from that direction can be calculated instantaneously, A detection input device was produced. The position detection performance was tested by bringing the produced input medium for the position detection input device close to the position information display screen of the obtained position detection input device. The test method is to select a total of nine locations on the position information display screen, and move the input medium for the position detection input device vertically up and down and close to and away from each other at 30 degrees and 45 degrees, It was measured how much the position coordinates of the magnet differ depending on the difference in the tilt angle of the input medium for the position detection input device. As a result, there was no difference in any inclination angle, and it was confirmed that the position coordinates of the magnet could be determined only by the distance and direction between the magnet and the magnetic sensor.

  The shape of the neodymium-based sintered magnet is a sphere with a diameter of 2 mm, an elliptic sphere with a short side diameter of 2 mm and a long side diameter of 2.5 m, and an elliptic sphere divided by half, and the center of gravity is biased at the bottom. Thus, except for cutting and grinding, respectively, an input medium for a position detection input device was prepared in the same manner as in Example 1, and then evaluated in the same manner using the position detection input device. As a result, it was confirmed that there was no difference in the measured value of the position coordinate in the inclination angle of the input medium for the position detection input device in any aspect, and the position coordinate of the magnet could be determined only by the distance and direction of the magnet and the magnetic sensor. .

  The shape of the neodymium sintered magnet is cut and ground so that it becomes a hollow hemispherical shape with a diameter of 2 mm as if the bowl is upside down, and then the needle is placed in a spherical space with a diameter of 2.5 mm of the input medium for the position detection input device. A hollow apex portion of the magnet is placed on the fulcrum, the magnet moves freely around the fulcrum, and the center of gravity of the magnet is below the fulcrum. Except for the above, an input medium for a position detection input device was produced in the same manner as in Example 1, and then evaluated in the same manner using the position detection input device. As a result, there was no difference in the inclination angle of the input medium for the position detection input device, and it was confirmed that the position coordinates of the magnet can be determined only by the distance and direction between the magnet and the magnetic sensor.

  The present invention is an invention of an input medium of a position detection input device that can be applied to an input device such as a mobile phone, a PDA, and a small PC.

DESCRIPTION OF SYMBOLS 3 Position information display screen 5 Magnetic sensor module 10 Input medium for position detection input devices 12 Magnet 14 Space where magnet is placed 16 Magnetic sensor 18 Center of gravity of magnet 20 Position detection input device 25 Calculation unit 30 Fixed point supporting magnet

Claims (4)

Larger pen like tip near inside the magnet, is formed a space for mounting the magnet, an input medium which can be the magnet in the space moves freely, the accordingly when tilting the input medium For the position detection input device , the magnet moves in the space, but the magnetic field of the magnet does not change even if the inclination of the input medium changes because the magnet has a shape in which the center of gravity is biased downward. Input medium.   The input medium for a position detection input device according to claim 1, wherein the magnet has one of a spherical shape, an elliptical spherical shape, a hemispherical shape, and a semi-elliptical spherical shape with a center of gravity biased at a lower portion.   The position detection input device input medium according to claim 1, wherein the magnet is placed with a fixed point in the space as a fulcrum, and the center of gravity of the magnet is below the fixed point.   The input medium for the position detection input device according to any one of claims 1 to 3 and a magnetic sensor that detects the strength of a magnetic field generated from a magnet of the input medium for the position detection input device. Position detection input device.

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