electronic pen

Abstract

Provided is an electronic pen that does not apply a large pressure to an operating surface, thereby enabling safe use with a foldable terminal and appropriately detecting pen pressure. A core unit (5) composed of a shaft (52), a core holding member (53), a piston spring (54), and a cylinder (55) housed in a unit housing (51) constitutes a pen pressure transmission unit that transmits the pen pressure applied to the core (4) to a pressure-sensing component (7) that functions as a pen pressure detection unit. The portion composed of the shaft (52), the piston spring (54), and the cylinder (55) functions as a buffer mechanism that absorbs a pen pressure exceeding a specified value when applied to the core, thereby preventing a load exceeding the specified value from being applied to the operating surface.

Description

Technical Field

[0001] The present invention relates to an electronic pen that functions as a position indicator for an electronic device such as a tablet PC (Personal Computer) equipped with a position detection device, for example. Background Art

[0002] Position detection devices and position indicators are used as input devices for various electronic devices, such as high-performance mobile phones like smartphones and tablet PCs (personal computers). Position indicators are generally pen-shaped and are called electronic pens or styluses. There are various types of position detection devices and position indicators. Among them, the active electrostatic (AES) method indicates the position on the position detection sensor by transmitting (radiating) a signal from an oscillating circuit mounted on the electronic pen from the pen tip toward the position detection sensor of the position detection device.

[0003] The position detection sensor used in an active capacitive position detection device is constructed by distributing linear transparent electrodes in the X-axis (horizontal) and Y-axis (vertical) directions on the display screen of a display device such as an LCD (Liquid Crystal Display). Therefore, the position detection sensor disposed on the display screen serves as the operating surface of the electronic pen. The position detection device detects the pointed position of the electronic pen based on the position of the linear transparent electrodes of the position detection sensor, which receives the signal (electric field) emitted by the electronic pen.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5761773 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] Information input using an electronic pen is performed by moving the tip of the electronic pen directly into contact with a position detection surface (operation surface) formed by a protective layer such as tempered glass over a position detection sensor, similar to writing with a pencil on paper. This allows the position detection device to capture the indicated position of the electronic pen as digital data representing the handwriting.

[0009] In recent years, mobile devices, known as foldable devices, have become available that can be folded in half or three times, including displays. Foldable devices allow for compact use and transport when folded, while a larger display is available when unfolded. However, due to their foldability, the OLED (Organic Light Emitting Diode) display used in foldable devices is flexible. This is because, because they are foldable, they do not require protective layers such as tempered glass.

[0010] Therefore, using an electronic pen to operate the operating surface of a foldable device can cause problems. Even if the tip of an electronic pen is made of a relatively soft material, it is still hard and sharp compared to a user's fingertip. In this case, the pressure per unit area is significantly greater than that of a fingertip. Using an electronic pen to operate the operating surface corresponding to the display screen of a foldable device could damage the operating surface or damage the light-emitting layer of the display device.

[0011] Furthermore, in electronic pens, the core may be elongated to accommodate electrodes for tilt detection on the pen tip, for example, by placing the pressure detection unit at the rear end of the pen. This elongation can cause the core to flex when pressure is applied, and it is thought that friction between the core and the surrounding walls within the pen housing can cause loss of pressure. Therefore, it is important to ensure that the core moves appropriately in the axial direction in response to pressure, ensuring that the pressure is properly transmitted to the pressure detection unit.

[0012] In view of the above, an object of the present invention is to provide an electronic pen that can detect writing pressure appropriately without applying a large pressure to an operating surface of a telecommunication device equipped with a position detection device, thereby enabling safe use of a foldable terminal.

[0013] Means for solving problems

[0014] In order to solve the above-mentioned problems, an electronic pen is provided, comprising:

[0015] A rod-shaped core having electrical conductivity;

[0016] a conductive writing pressure transmitting unit connected to the core body and transmitting the writing pressure applied to the core body to the writing pressure detecting unit; and

[0017] a transmitting unit, generating a signal to be sent from the core,

[0018] The electronic pen is characterized in that:

[0019] The writing pressure transmitting portion is provided with a buffer mechanism for absorbing the writing pressure when a writing pressure exceeding a predetermined value is applied to the core body.

[0020] The signal from the transmitting unit is supplied to the core body through the writing pressure transmitting unit, and is transmitted to the outside through the core body.

[0021] According to this electronic pen, it is an electronic pen that includes a core body, a writing pressure transmission unit connected to the core body, and a transmitting unit. The core body and the writing pressure transmission unit are both conductive, and the signal from the transmitting unit is supplied to the core body through the writing pressure transmission unit, and is transmitted from the core body to the outside, thereby realizing the function of the electronic pen. In addition, the writing pressure applied to the core body is transmitted to the writing pressure detection unit through the writing pressure transmission component. The writing pressure transmission unit of the electronic pen is provided with a buffer mechanism that absorbs the writing pressure when a writing pressure exceeding a specified value is applied to the core body. Therefore, the writing pressure that does not exceed the specified value can be appropriately detected, and even if a writing pressure exceeding the specified value is applied, excessive pressure will not be applied to the operating surface on the side of the position detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram for explaining a configuration example of an electronic pen according to an embodiment.

[0023] Figure 2 This is a diagram for explaining the main parts on the pen tip side of the electronic pen according to the embodiment.

[0024] Figure 3 This is a diagram for explaining a portion of the electronic pen according to the embodiment that realizes the functions of detecting writing pressure and transmitting signals.

[0025] Figure 4 These are diagrams for explaining changes in the electronic pen core according to the embodiment.

[0026] Figure 5 These are diagrams for explaining changes in the electronic pen core according to the embodiment.

[0027] Figure 6 It is a diagram for explaining another structural example of the electronic pen core body according to the embodiment. DETAILED DESCRIPTION

[0028] An embodiment of the electronic pen of the present invention is described below with reference to the drawings. The electronic pen of the embodiment described below uses an active capacitive method, in which a signal is sent from the electronic pen and the position of the indicated position is detected based on the position of the position detection sensor that receives the signal.

[0029] [Configuration Example of the Electronic Pen 1]

[0030] Figure 1 1 is a diagram for explaining a configuration example of the electronic pen 1 according to this embodiment. For the purpose of explanation, a portion of the outer shell (housing) 2 of the electronic pen 1 is cut away to show the interior. Figure 2: is a diagram (enlarged cross-sectional view) for explaining the main part of the pen tip side of the electronic pen 1. Figure 3 This is a diagram (schematic diagram) for explaining a portion of the electronic pen 1 that realizes the functions of writing pressure detection and signal transmission.

[0031] like Figure 1 As shown, the electronic pen 1 includes a housing (casing) 2. The housing 2 is axially elongated (along the axis), having a cylindrical shape with one axial end opening toward the pen tip and the other axial end closed. The housing 2 comprises a cylindrical housing body 21 having a hollow interior, and a front cap 22 and a rear cap 23 coupled to the housing body 21. The front cap 22 and rear cap 23 are fitted into the housing body 21 to complete the housing 2.

[0032] The housing body 21 and rear cap 23 are formed of a conductive material. In this embodiment, the housing body 21 and rear cap 23 are formed of, for example, anodized aluminum. Furthermore, the front cap 22 is formed of a non-conductive material. In this embodiment, the front cap 22 is formed of, for example, plastic.

[0033] like Figure 2 As shown, the front cap 22 is configured as a cylindrical body having a through hole in the axial direction through which the electronic pen core 4 passes, and the outer shape of the portion on the pen tip side of the electronic pen 1 is a tapered shape with the outer diameter decreasing as it approaches the pen tip. It should be noted that the electronic pen core 4 will be referred to as simply the core 4 below. The end of the front cap 22 on the pen tip side is the opening of the through hole through which the core 4 passes. Figure 1 As shown, a substrate holder 3 for holding mounted components such as a printed circuit board 8 and a battery 9 are housed in the hollow portion of the housing 2 , and components for realizing the function of the electronic pen are housed on the pen tip side.

[0034] like Figure 2 As shown, the core unit 5, the internal shell 6, the pressure-sensitive component (pen pressure detection unit) 7, the tilt detection electrode 13, and the grounding ring 16 are stored on the front cap 22 side of the outer shell 2. The internal shell 6 is formed in a cylindrical shape, similar to the front cap 22, and is set to a tapered shape with an outer diameter that decreases as it approaches the pen tip. The internal shell 6 is formed of a non-conductive material, and in this embodiment, it is formed of plastic, for example. A slight gap is provided between the front cap 22 and the internal shell 6 and on the pen tip side, where the tilt detection electrode 13 is provided. The tilt detection electrode 13 is formed by winding a conductive wire in a coil shape on the outer side surface of the pen tip side of the internal shell 6.

[0035] The core unit 5 is mounted inside the inner housing 6. The core unit 5 is constructed by mounting a shaft 52, a piston spring 54, and a cylinder 55 inside a cylindrical unit housing 51, starting from the pen tip side. The shaft 52 consists of a core holder 521, which is cup-shaped and has an opening on the pen tip side, and a cylindrical piston 522, which extends from the bottom of the core holder 521 toward the rear end of the electronic pen 1. The shaft 52, consisting of the core holder 521 and the piston 522, is made of a conductive material, for example, metal in this embodiment.

[0036] A core holding member 53 formed into a cylindrical shape is provided inside the core holding portion 521 of the shaft portion 52. Figure 2 As shown, the rear end face of the core holding member 53 contacts the rear end face of the core holding portion 521, and the tip end face of the extension extending from the side of the core holding member 53 contacts the tip end face of the core holding portion 521. Thus, the core holding member 53 is fixed within the core holding portion 521 of the shaft portion 52.

[0037] The core holding member 53 is formed of a conductive elastic member, and in this embodiment, is formed of, for example, conductive rubber. The core 4 can be installed relative to the shaft portion 52 by inserting the rear end side of the core 4 relative to the core holding member 53, and can also be removed by pulling it out. That is, the core 4 can be installed and removed relative to the core holding member 53 of the core holding portion 521 provided on the shaft portion 52. It should be noted that the core 4 is formed into a rod shape by a conductive material, such as Figure 2 As shown, it has a main body portion 41 and a pen tip portion 42.

[0038] A piston spring 54 is provided around the piston portion 522 of the shaft portion 52. The piston spring 54 is formed of a conductive material, for example, stainless steel (SUS304) in this embodiment. A cylinder portion 55 is provided at the rear of the shaft portion 52 and the piston spring 54.

[0039] The cylinder portion 55 consists of a cylinder body 551, which is cylindrical in shape due to a cylindrical hole extending from the pen tip toward the rear end, and a rod-shaped cylinder connection portion 552 extending from the outside of the bottom of the cylinder body 551 toward the rear end. The rear end of the cylinder body 551 is closed, forming the bottom. Furthermore, a first annular protrusion 551a and a second annular protrusion 551b are provided on the outside of the cylinder body 551. The cylinder portion 55 is formed of a conductive material, for example, metal in this embodiment.

[0040] The diameter of the cylindrical piston portion 522 of the shaft portion 52 is slightly shorter than the inner diameter of the hole portion of the cylinder body portion 551 of the cylinder portion 55. Figure 2 、 Figure 3As shown, the piston portion 522 of the shaft portion 52 can be inserted into the hole portion of the cylinder body portion 551, and the piston portion 522 can slide (move in and out) in the cylinder body portion 551 according to the writing pressure. Figure 2 、 Figure 3 As shown, when the rear end of the piston portion 522 is inserted into the hole of the cylinder body portion 551, the piston spring 54 is in contact with the outer side of the bottom surface of the core holding portion 521 of the shaft portion 52 and the cylinder body portion 551 of the cylinder portion 55. Thus, the piston spring 54 electrically connects the shaft portion 52 and the cylinder portion 55.

[0041] The piston spring 54 is sandwiched between the outer bottom surface of the core retaining portion 521 of the shaft 52 and the first annular protrusion 551a provided on the cylinder body 551 of the cylinder 55, and acts between the two. In this case, when a writing pressure not exceeding a specified value is applied to the core 4, the piston spring 54 does not contract (deflect), and the piston 522 does not enter the cylinder body 551. If a writing pressure exceeding the specified value is applied to the core 4, the piston spring 54 begins to contract (deflect), and the piston 522 gradually enters the cylinder body 551 in accordance with the writing pressure.

[0042] Thus, the shaft 52, piston spring 54, and cylinder 55 form a buffer mechanism that absorbs writing pressure exceeding a specified value. It should be noted, as will be discussed later, that the piston spring 54 in this embodiment begins to deflect when a load of 300 gf (gram-force) is applied. Therefore, the piston spring 54 does not contract (deflect) under writing pressures less than 300 gf, but gradually begins to contract (deflect) when a writing pressure exceeding 300 gf is applied.

[0043] In addition, the shaft 52 and the core holding member 53, the piston spring 54, and the cylinder 55 are used to maintain Figure 2 The pen holder 521 of the shaft 52 is housed in the unit housing 51 in the state shown. Specifically, the outer protrusion 521a extending annularly from the rear end side surface of the core holding portion 521 of the shaft 52 engages with the front extension 51a extending inwardly from the pen tip side of the unit housing 51. Furthermore, the second annular protrusion 551b of the cylinder body 551 engages with the rear extension 51b extending annularly from the rear end portion of the unit housing 51.

[0044] Thus, the unit housing 51 is maintained. Figure 2 、 Figure 3The illustrated state houses the shaft 52, core retaining member 53, piston spring 54, and cylinder 55. Therefore, the core unit 5, which houses the shaft 52, core retaining member 53, piston spring 54, and cylinder 55 within the unit housing 51, can be used as a single conductive component, or writing pressure transmission unit, that transmits writing pressure applied to the core. Furthermore, as described above, the core unit 5, which functions as a writing pressure transmission unit, includes a buffer mechanism that absorbs writing pressure exceeding a predetermined value.

[0045] In the core unit 5 thus constructed, the rear end side of the cylinder main body 551 of the cylinder portion 55 and the cylinder connecting portion 552 protrude from the rear end of the unit case 51 and are connected to the pressure sensing member 7. Figure 2 As shown, in the non-use state where no writing pressure is applied to the core 4, a gap SP is provided between the rear end surface of the unit housing 51 and the front end surface of the pressure-sensing member 7, as indicated by the arrow. Although described later, the gap SP allows the core unit 5 to move in the axial direction within a range of writing pressure less than 300 gf applied to the core 4, thereby enabling appropriate detection of writing pressure less than 300 gf.

[0046] The pressure-sensing component 7 consists of a pressure-sensing housing 71, a housing cover 72, a conductive spring 73, a pressing member holder 74, a pressing member 75, a first electrode 76, a spacer 77, a dielectric 78, and a second electrode 79. The housing cover 72, which has a through-hole in its center, is fixed to the tip-side end of the pressure-sensing housing 71, securing the components of the pressure-sensing component 7 within the pressure-sensing housing 71. The pressure-sensing housing 71 and the housing cover 72 are formed of a non-conductive material, and in this embodiment, are made of plastic.

[0047] A conductive spring 73 made of a conductive material is provided inside the pressure sensing portion housing 71 and near the through hole of the housing cover 72. Figure 2 As shown, when the cylinder coupling portion 552 of the cylinder 55 and the rear end of the cylinder body 551 are inserted into the through hole of the housing cover 72, the conductive spring 73 contacts and electrically connects the cylinder body 551. The conductive spring 73 supplies a signal to the cylinder 55.

[0048] It should be noted that the conductive spring 73 is fixed to the inner bottom surface of the housing cover 72 and acts between the rear end of the cylinder body 551 and the inner bottom surface of the housing cover 72, thereby pushing the core unit 5 back toward the pen tip. Furthermore, the conductive spring 73 is shaped like a coil spring, so it can expand and contract even when the cylinder 55 slides, and the electrical connection between the conductive spring 73 and the cylinder body 551 is always maintained.

[0049] A pressing member 75 is located on the rear end of the housing cover 72 and is housed in a pressing member holder 74. The pressing member holder 74 and the pressing member 75 are formed of a non-conductive material, or plastic in this embodiment. Furthermore, the pressing member 75 is movable within the pressing member holder 74 in the axial direction of the electronic pen 1.

[0050] A first electrode 76, a spacer 77, a dielectric 78, and a second electrode 79 are provided on the rear end of the pressing member 75. The first electrode 76 is formed of a conductive elastic member. In this embodiment, the first electrode 76 is formed of conductive rubber. The spacer 77 is formed into a ring shape from a non-conductive material (such as plastic). It is used to provide a space (gap) corresponding to the thickness of the spacer 77 between the first electrode 76 and the front end surface (end surface on the pen tip side) of the rear-stage dielectric 78. The dielectric 78 is formed of ceramic, for example. The second electrode 79 is provided so as to contact the rear end surface of the dielectric 78.

[0051] like Figure 2 As shown, the pressure-sensing housing 71 of the pressure-sensing component 7 having such a structure is inserted from the opening on the rear end side of the internal housing 6 and fixed to the internal housing 6. In this case, the cylinder connecting portion 552 of the cylinder portion 55 and the rear end side portion of the cylinder main body 551 are inserted into the pressure-sensing component 7 through the through hole of the housing cover 72, and the cylinder connecting portion 552 is inserted into the hole provided on the pen tip side of the pressing member 75 and is held (fixed). In addition, as Figure 2 、 Figure 3 As shown, the rear end portion of the core 4 is laterally inserted into the core holding member 53 fixed to the inner side of the core holding portion 521 of the shaft portion 52 and fixed to the shaft portion 52 .

[0052] As a result, the core 4, shaft 52, piston spring 54, cylinder 55, and pressure-sensing component 7 are arranged in series along the axis of the electronic pen 1. In this case, within the pressure-sensing component 7, the pressing member 75, first electrode 76, spacer 77, dielectric 78, and second electrode 79 arranged in series form a variable-capacitance capacitor (capacitor). Therefore, depending on the pressure applied to the core 4, the pressing member 75 presses the first electrode 76, moving it closer to or further away from the dielectric 78, causing the electrostatic capacitance between the first electrode 76 and the second electrode 79 to change. This change in electrostatic capacitance allows detection of writing pressure.

[0053] Moreover, although Figure 2 Although not shown in the figure, the pressure sensing portion housing 71 is closed at the rear end side of the second electrode 79. Figure 1As shown, the substrate holder 3 is connected to the substrate holder 3 provided in the housing 2 of the electronic pen 1 and is fixed in the housing 2. The substrate holder 3 is formed of an insulating resin (e.g., liquid crystal polymer). The substrate holder 3 has a pressure-sensitive component holding portion (not shown) and a pressure-sensitive component holding portion (not shown) in the axial direction of the electronic pen 1 when housed in the hollow portion of the housing 2. Figure 1 As shown, the printed circuit board mounting table portion 3a extending in the axial direction is continuous.

[0054] The pressure-sensing component holding portion of the substrate holder 3 is located on the pen tip side of the printed substrate mounting base portion 3a. It is formed into a circular shape that covers the rear end surface of the pressure-sensing component 7, has a predetermined thickness, and has an outer diameter slightly smaller than the inner diameter of the through-hole of the front cap 22. The printed substrate mounting base portion 3a is a boat-shaped structure that mounts and holds the printed substrate 8. Specifically, it is a structure formed by cutting a cylindrical body approximately in half along the axial direction.

[0055] The substrate holder 3 is arranged so that the pressure-sensitive component holding portion is on the main body 41 side of the core 4, and the entire pressure-sensitive component holding portion and the printed circuit board mounting table portion 3a are housed in the housing 2 and fixed so as not to move. Figure 2 As shown, the internal case 6 , the pressure-sensing component 7 , and the grounding ring 16 are fixed in position within the outer shell 2 , and the writing pressure applied to the core 4 is appropriately transmitted to the pressure-sensing component 7 .

[0056] like Figure 1 As shown, a terminal conductor 91 is provided at the end of the printed circuit board mounting platform portion 3a of the substrate holder 3 on the side opposite to the pen tip side. This terminal conductor 91 is electrically connected to the positive terminal 9a of the battery 9 and is electrically connected to the copper foil pattern of the power supply line of the printed circuit board 8. A coil spring terminal 92 made of conductive metal is provided at the fitting portion of the rear cap 23 and the housing body 21. Figure 1 As shown, the battery 9 is inserted into the case 2 with the positive terminal 9a connected to the terminal conductor 91. Thereafter, the rear cap 23 is fitted to the case body 21 with the coil spring terminal 92 pressing the negative terminal 9b of the battery 9.

[0057] In this embodiment, the housing body 21, made of a conductive material, is electrically connected to the ground conductor of the printed circuit board 8 via, for example, the aforementioned ground ring 16. Since the back cap 23 and the housing body 21 are made of a conductive material, the negative terminal 9b of the battery 9 is electrically connected to the ground conductor of the printed circuit board 8 via these back cap 23 and the housing body 21. Meanwhile, the positive terminal 9a of the battery 9 is connected to the copper foil pattern of the power supply line on the printed circuit board 8 via a terminal conductor 91. This allows the voltage of the battery 9 to be supplied as the power supply voltage to the circuits formed on the printed circuit board 8.

[0058] The printed circuit board 8 is provided with a transmitting section (signal generating circuit) 8s, a detecting section 8d for detecting the electrostatic capacitance for detecting the writing pressure, Figure 1 The control IC (Integrated Circuit) 10 and other peripheral circuit components constitute the circuit unit. The transmitter 8s generates a signal to be sent from the core 4 of the electronic pen 1. The control IC 10 constitutes a control circuit that controls the transmission of the signal from the transmitter 8s to the core 4. The peripheral circuit unit includes Figure 1 The push switches (side switches) 11 and 12 are shown. Figure 3 As shown, the printed circuit board 8 is connected with a conductive line 14 connecting the core 4, the tilt detection electrode 13 and the transmitter 8s, and a conductive line 15 transmitting the detection output of the writing pressure from the pressure sensing member 7 to the detector 8d for detecting electrostatic capacitance.

[0059] In addition, as described above, the core 4, the core holding member 53, the shaft 52, the piston spring 54, the cylinder 55, and the conductive spring 73 are each formed of a conductive material and are electrically connected. Figure 3 As shown, a signal is supplied from the transmitter 8s mounted on the printed circuit board 8 to the conductive spring 73 and the tilt detection electrode 13 via two conductive wires 14. That is, the position indication signal of the frequency f1 from the transmitter 8s is supplied to the conductive spring 73.

[0060] This position indication signal is supplied from conductive spring 73 through cylinder 55 to piston spring 54, from piston spring 54 through shaft 52 to core retaining member 53, and from core retaining member 53 to core 4, where it is transmitted externally. The position indication signal transmitted from core 4 is sent to a position detection sensor mounted on a position detection device, such as a tablet PC, and used to detect the indicated position. Furthermore, a tilt detection signal at frequency f2 from transmitting unit 8s is supplied to tilt detection electrode 13 and transmitted externally from tilt detection electrode 13. The signal transmitted from tilt detection electrode 13 is sent to a position detection sensor mounted on a position detection device, such as a tablet PC, and used to detect the tilt of electronic pen 1.

[0061] In addition, if Figure 3 As shown, conductive wires 15 extending from first electrode 76 and second electrode 79 of pressure-sensing component 7 are supplied to capacitance detection unit 8d on printed circuit board 8, which detects capacitance that changes in response to writing pressure. Information representing the capacitance detected by detection unit 8d is supplied to control IC 10 mounted on printed circuit board 8. This information changes the position indication signal transmitted by transmission unit 8s, which then includes writing pressure information and is transmitted to the position detection sensor. This allows the position detection device to detect not only position indication but also writing pressure.

[0062] Specifically, the control IC 10 of the electronic pen 1 controls the position detection sensor so that it sends a burst signal (position indication signal) for coordinate detection (position detection) corresponding to the signal from the transmitter 8s. This allows the position detection sensor to detect the position indicated by the electronic pen 1 on the position detection sensor. Furthermore, in the circuitry including the control IC 10, which is included in the printed circuit board 8 of the electronic pen 1, during the period during which the burst signal is sent, the pressure-sensing component 7 performs an operation to detect the pen pressure based on electrostatic capacitance. After the burst signal transmission period ends, the control IC 10 modulates the signal from the transmitter 8s according to the detected pen pressure, and transmits a coded signal from the core 4 to the position detection sensor, notifying the position detection sensor of the pen pressure. This allows the position detection sensor to detect the pen pressure applied to the core 4 of the electronic pen 1.

[0063] As described above, the transmission unit 8s makes the frequencies of the position detection signal supplied to the conductive spring 73 and the tilt detection signal supplied to the tilt detection electrode 13 different, but the present invention is not limited to this. If the tilt detection signal is transmitted at a timing different from that of the position detection signal and the pen pressure detection signal, the position detection signal and the tilt detection signal may have the same frequency. In the case of the electronic pen 1 of this embodiment, if Figure 2 As shown in FIG. 1 , a cylindrical ground ring 16 made of a conductive material is provided around the pressure sensing component 7 and is used as a grounding member for the electrical system.

[0064] The electronic pen 1 with this structure can indicate the position on the position detection sensor, detect the writing pressure applied to the core 4, and notify the position detection sensor. In addition, the tilt of the electronic pen 1 can be detected by sending a signal from the tilt detection electrode 13 to the position detection sensor.

[0065] [Details of the operation of the electronic pen 1]

[0066] With use Figures 1 to 3 The electronic pen 1 of the embodiment of the structure described above has a function that conventional electronic pens do not have due to its structural features. One of its structural features is that it has a buffer mechanism consisting of a shaft 52, a piston spring 54, and a cylinder 55. Another feature is that Figure 2 As indicated by the arrow in FIG. 1 , a gap SP is provided between the rear end surface of the unit case 51 of the core unit 5 and the front end surface of the pressure-sensing member 7 , so that the core unit 5 can slide in the axial direction of the electronic pen 1 .

[0067] First, let's consider the case where no writing pressure is applied to the core 4. As mentioned above, the piston spring 54 provided between the shaft 52 and the cylinder 55 will not contract unless a writing pressure of 300 gf or more is applied. Figure 2 In the illustrated state, a load of 300 gf is applied, and the piston spring 54 is supported between the outer bottom surface of the core retaining portion 521 of the shaft portion 52 and the first annular protrusion 551a provided on the cylinder body 551 of the cylinder portion 55. However, the 300 gf load is not applied to the pressure-sensing member 7.

[0068] Therefore, when no pressure is applied to the core 4, Figure 2 As shown, the piston spring 54 does not contract, and the piston portion 522 does not move toward the rear end side inside the cylinder body portion 551 of the cylinder portion 55. Of course, the gap SP between the rear end surface of the unit housing 51 of the core unit 5 and the front end surface of the pressure sensing member 7 does not change. Figure 2 The shown state is maintained.

[0069] Next, consider the case where a writing pressure greater than 0 gf but less than 300 gf is applied to the core 4. In this case as well, since the writing pressure is less than 300 gf, the piston spring 54 does not contract, and the piston portion 522 does not move toward the rear end within the cylinder body 551 of the cylinder portion 55. However, the core unit 5 moves toward the rear end of the electronic pen 1 in response to the writing pressure applied to the core, shortening the distance (gap SP) between the rear end surface of the unit housing 51 of the core unit 5 and the front end surface of the pressure-sensing member 7.

[0070] Thus, the first electrode 76 is pushed up toward the rear end by the pressing member 75 connected to the cylinder connection part 552, causing the electrostatic capacitance between the first electrode 76 and the second electrode 79 to change, thereby enabling detection of the writing pressure. That is, when the writing pressure applied to the core 4 is greater than 0gf and less than 300gf, it can be properly detected by the pressure-sensing component 7. If the writing pressure applied to the core 4 is released, the core unit 5 and the core 4 are pushed back by the elastic force of the first electrode 76 and the action of the conductive spring 73, and return to the original state. Figure 2 The initial state is shown.

[0071] Next, consider the case where a writing pressure of 300 gf or more is applied to the core body 4. In this case, the piston spring 54, which is set to a load of 300 gf, contracts, and the piston portion 522 moves toward the rear end side inside the cylinder body portion 551 of the cylinder portion 55. As a result, the writing pressure of 300 gf or more applied to the core body 4 is absorbed by the buffer mechanism composed of the shaft portion 52, the piston spring 54 and the cylinder portion 55. Therefore, even if a writing pressure of 300 gf or more is applied to the core body 4, it is possible to avoid applying a load of 300 gf or more to the operating surface of the tablet PC or the like that the core body 4 contacts. As a result, it is possible to realize an electronic pen 1 that is suitable for use with a foldable terminal (foldable terminal) having an operating surface that may be damaged or otherwise suffer adverse conditions if a load of 300 gf or more is applied.

[0072] Thus, in the electronic pen 1 of this embodiment, the core 4, shaft 52, core holding member 53, piston spring 54, cylinder 55, and conductive spring 73 are all formed of conductive materials and are electrically connected, thereby realizing an active capacitive electronic pen.

[0073] Furthermore, the core 4, shaft 52, core holding member 53, piston spring 54, and cylinder 55 are arranged in series and in a straight line toward the pressure-sensing component 7. This allows the pressure-sensing component 7 to be pressed straightly without lengthening the core 4 itself, enabling appropriate detection of writing pressure without loss of writing pressure.

[0074] Furthermore, the shaft 52, core retaining member 53, piston spring 54, and cylinder 55 function as a buffer mechanism. In this embodiment, this buffer mechanism absorbs pen pressures exceeding 300 gf applied to the core 4. This makes it possible to realize an electronic pen suitable for use with foldable devices, which, unlike conventional tablet PCs having operating surfaces protected by tempered glass or the like, cannot be provided with a protective layer such as tempered glass on the operating surface.

[0075] It should be noted that the electronic pen 1 of this embodiment cannot detect pressure exceeding 300 gf applied to the core 4. However, when using a tablet PC, there is no need to apply pressure exceeding 300 gf to the core of the electronic pen. Therefore, even when using the electronic pen 1 of this embodiment with a foldable device, no problems will occur. Of course, the electronic pen 1 of this embodiment can fully function as an electronic pen even when used with conventional tablet PCs with an operating surface made of tempered glass or the like.

[0076] [Improvement of the Pen Tip of Core 4]

[0077] The core 4 of the electronic pen 1 in this embodiment is formed of a conductive material. Examples of conductive materials include metal and conductive resin. However, using these conductive materials to form the core 4 would make it thin and rigid. As mentioned above, the electronic pen 1 includes a cushioning mechanism, so loads exceeding 300 gf are not applied to the operating surface. However, further protection of the operating surface is desirable, if possible. Furthermore, when using the electronic pen 1 for input, a soft writing feel is desirable. Therefore, a cover is provided at the tip portion 42 of the core 4.

[0078] That is, Figure 2 As shown, the core 4 is composed of a main body 41 and a pen tip 42. The main body 41 is rod-shaped (cylindrical). The pen tip 42 is provided at one end side of the main body 41 in the longitudinal direction, has a diameter longer than the diameter of the main body 41, and has a tapered shape that becomes thinner from the main body 41 side (rear end side) toward the front end side. The main body 41 and the pen tip 42 are integrally formed of the same conductive material, and the diameter is also long. It is a hard and strong part. As the conductive material, for example, various hard conductive resins, metals such as copper, etc. can be used.

[0079] A cup-shaped cover 43 is provided at the tip of the pen tip 42, matching the tip. Cover 43 is a cup-shaped (dome-shaped) member that covers the entire outer surface of the pen tip 42 and is made of a compressible / expandable material. Specifically, cover 43 is formed into a sponge or rubber-like shape, and like a human fingertip (the area with fingerprints and the surrounding area), it has elastic properties, compressing and contracting when pressed, and expanding and returning to its original state when the pressure is released.

[0080] Regarding forming the cover portion 43 into a sponge shape, for example, there are foamed sponges formed by foaming resin materials such as polyurethane resin, rubber sponges obtained by foaming rubber materials such as natural rubber and synthetic rubber, and the like. Regarding forming the cover portion 43 into a rubber shape, in addition to natural rubber and synthetic rubber, there are also various materials that have elastic force like natural rubber and synthetic rubber, contract when pressed, and return to their original state when the pressure is released. In addition, materials such as polyurethane resin and silicon can also be used to form the cover portion 43 that can be compressed / expanded. In addition, the cover portion 43 can also be formed by overlapping fabrics formed into a mesh shape. In short, the cover portion 43 can be formed using various materials in a manner such that, like sponges and rubbers, they compress and contract when pressed, and expand and return to their original state when the pressure is released.

[0081] By providing the compressible / expandable cover 43 to cover the entire outer surface of the pen tip 42, when the electronic pen 1 is used to operate the operating surface on the display screen of an electronic device, the force applied by the electronic pen 1 to the operating surface is absorbed by the cover 43. This prevents the instantaneous application of large forces to the operating surface, i.e., the display screen of the display device mounted on the electronic device, thereby protecting the display screen. Consequently, the electronic pen 1 of this embodiment is designed to be more suitable for use with foldable devices, without damaging the display screen of the foldable device, as is the case with foldable devices.

[0082] It should be noted that the outer surface of the pen tip 42, unless the cover 43 is present, refers to the outer surface of the pen tip 42 that can contact the operating surface. The cover 43 is attached to the pen tip 42, tightly adhering to the pen tip 42. The core 4 is attached to the electronic pen, allowing it to be used as an electronic pen. To make it more difficult to remove the cover 43 from the pen tip 42, the cover 43 can be bonded to the pen tip 42 using an adhesive.

[0083] [Changes (Modifications) of the Core 4]

[0084] As described above, the cup-shaped cover 43 covering the outer surface of the pen tip 42 of the core body 4 is provided to protect the operating surface and improve the writing feel. However, the cover 43 is not limited to the cup shape. Figure 4 、 Figure 5 It is a diagram for explaining changes in the core 4.

[0085] Figure 4 The core 4A shown in (A) is similar to the core 4 described above, consisting of a main body 41A, a nib 42A, and a cover 43A. However, the cover 43A in this example is of an insertable type, with an insert 43Aa extending from the inner vertex of the dome-shaped cover 43A through the axis toward the opening of the cover 43A. In this example, the insert 43Aa is formed from the same material as the portion of the cover 43A that covers the outside of the nib 42A.

[0086] It should be noted that the insertion portion 43Aa may be compressed or otherwise made harder than the portion of the cover portion 43A covering the outside of the pen tip 42A, thereby being processed to facilitate insertion. Furthermore, the insertion portion 43Aa may be formed of a different material than the portion of the cover portion 43A covering the outside of the pen tip 42A. The insertion portion 43Aa can have various shapes, but in this example, it is cylindrical.

[0087] The pen tip 42A is provided with an insertion hole 42Aa. Insertion hole 42Aa is a hole into which insertion portion 43Aa of cover 43A is inserted. Insertion hole 42Aa extends from the apex through the axis toward main body 41A. The axial length of insertion hole 42Aa is equal to or longer than insertion portion 43Aa. Furthermore, the diameter of insertion hole 42Aa is equal to or slightly shorter than the diameter of insertion portion 43Aa.

[0088] like Figure 4 As shown in (A), in the case of the core 4A, the insertion portion 43Aa of the cover portion 43A is inserted into the insertion hole 42Aa provided in the pen tip portion 42A, so that the inner surface (inner surface) of the cover portion 43A and the outer surface (outer surface) of the pen tip portion 42A are in close contact. In this way, the cover portion 43A can be assembled on the pen tip portion 42A. In this case, the cover portion 43A will not leave or deviate from the pen tip portion 42A by fitting the insertion portion 43Aa into the insertion hole 42Aa. In addition, there is no need to use adhesives or the like. Therefore, the cover portion 43A assembled on the pen tip portion 42A can also be easily disassembled.

[0089] It should be noted that the shape of the insertion portion 43Aa is not limited to a cylindrical shape and can be formed into a columnar body with a cross-sectional shape in a direction intersecting the axial direction, such as a square column. Furthermore, the insertion hole 42Aa can also be configured in various shapes corresponding to the insertion portion 43Aa. Furthermore, the insertion portion 43Aa and the insertion hole 42Aa do not need to be identical in shape, as long as they can be inserted and do not easily come loose during use. Furthermore, the length of the insertion portion 43Aa and the insertion hole 42Aa can be set to an appropriate length to facilitate insertion and removal and prevent them from easily falling off during use.

[0090] Figure 4 The core 4B shown in (B) is similar to the core 4 described above and is composed of a main body 41B, a nib 42B, and a cover 43B. However, the cover 43B in this example is embedded, and an inwardly extending extension 43Ba is provided at the dome-shaped opening of the cover 43B. The extension 43Ba is an annular portion formed so as to extend along the inner edge of the opening of the cover 43B. In this example, the extension 43Ba is formed from the same material as the portion of the cover 43B that covers the outer surface of the nib 42B.

[0091] In the pen tip portion 42B, a groove portion 42Ba is provided in an annular shape at the position where the extension portion 43Ba of the cover portion 43B is fitted when the cover portion 43B is assembled. The depth of the groove portion 42Ba (the depth in the direction intersecting the axis) is the same as the length of the portion of the extension portion 43Ba that extends inward. In addition, the length of the groove portion 42Ba in the axial direction is the same as the thickness of the extension portion 43Ba in the axial direction, or is slightly shorter than the thickness of the extension portion 43Ba. That is, as Figure 4As shown in (B), the shape of the groove portion 42Ba is a shape into which the extension portion 43Ba of the cover portion 43B fits.

[0092] In this case, if Figure 4 As shown in (B), in the case of the core 4B, the pen tip 42B is inserted from the opening of the cover 43B, the cover 43B is placed on the pen tip 42B, and the extension 43Ba of the cover 43B is engaged with the groove 42Ba of the pen tip 42B. In this way, the inner wall surface of the cover 43B and the outer wall surface of the pen tip side of the pen tip 42B can be closely attached, and the cover 43B can be assembled to the pen tip 42B. In this way, by engaging the extension 43Ba with the groove 42Ba, the cover 43B will not leave or deviate from the pen tip 42B. In addition, there is no need to use adhesives or the like. Therefore, the cover 43B assembled to the pen tip 42B can also be easily disassembled.

[0093] Figure 4 The core 4C shown in (C) is similar to the core 4 described above and is composed of a main body 41C, a pen tip 42C, and a cover 43C. Figure 4 The core 4B shown in (B) is similarly embedded, but unlike the core 4B, it is assembled so as to completely cover the outer surface of the pen tip 42C. Specifically, in the case of the core 4C, the opening of the dome-shaped cover 43C is also provided with an inwardly extending extension 43Ca. Specifically, the extension 43Ca is an annular structure extending along the inner edge of the opening of the cover 43C. In this example, the extension 43Ca is formed from the same material as the other parts of the cover 43C.

[0094] The pen tip 42C has an annular extension 42Ca formed at the boundary with the main body 41C. The extension 42Ca has the same length as the inner extension of the cover 43C. Figure 4 As shown in FIG. 1A , the shape of the space inside the cover 43C and the shape of the portion of the nib 42C into which the cover 43C is mounted are substantially identical. Therefore, when the nib 42C is inserted through the opening of the cover 43C and the cover 43C is placed over the nib 42C, the extension 42Ca of the nib 42C and the extension 43Ca of the cover 43C extend in opposite directions, thereby fitting securely.

[0095] That is, Figure 4As shown in (C), in the case of the core 4C, the cover 43C is placed on the nib 42C, and the extension 43Ca of the cover 43C is engaged with the extension 4Ca of the nib 42C. This allows the inner wall surface of the cover 43C and the outer wall surface of the nib 42C to be in close contact, allowing the cover 43C to be mounted on the nib 42C. In this case, by engaging the extension 43Ca with the extension 42Ca, the cover 43C will not separate from or deviate from the nib 42C. Furthermore, there is no need to use adhesives or the like. Therefore, the cover 43C mounted on the nib 42C can be easily disassembled. Of course, it is also possible to slightly enlarge or reduce one of the internal space of the cover 43C and the portion of the nib 42C where the cover 43C is mounted, in a similar shape, so as to achieve a closer contact or have a slight margin.

[0096] Figure 5 The core 4D shown in (A) is similar to the core 4 described above and is composed of a main body 41D, a pen tip 42D, and a cover 43D. The cover 43D in this example is different from the cover 43, 43A, 43B, and 43C described above in that the tip portion, which becomes the pen tip, is thicker. The rest of the structure is similar to that used in the present invention. Figure 1 、 Figure 2 The core 4 described above is substantially the same in structure. Therefore, the cover portions 43, 43A, 43B, and 43C described above can also be replaced as shown in FIG. Figure 5 That is, the cover parts 43, 43A, 43B, 43C can be formed into various shapes, such as thickening or thinning the front end, flattening the front end, or thickening or thinning the side parts.

[0097] Figure 5 The core 4E shown in (B) is similar to the core 4 described above and is composed of a main body 41E, a pen tip 42E, and a cover 43E. Figure 4 In contrast to the core 4A shown in (A), a convex portion 42Ea is provided at the central portion of the front end of the pen tip portion 42E. Correspondingly, a concave portion is provided at the central portion of the inner side of the cover portion 43E. Thus, when the cover portion 43E is assembled to the pen tip portion 42E, the contact area can be increased and the cover portion 43E can be assembled stably to the pen tip portion 42E. In this case, the cover portion 43E can be provided at the front end portion of the pen tip portion 42E that must be in contact with the operating surface. It should be noted that in Figure 5 In the case of the core 4E shown in (B), the cover portion 43E and the pen tip portion 42E are preferably bonded together by an adhesive or the like.

[0098] [Other structural examples of parts other than the cover portion of the core]

[0099] In use Figures 1 to 3In the core 4 described above, the main body 41 and the pen tip 42 are integrally formed of a conductive material. Therefore, the core 4 is hard and strong as a whole. Therefore, it is described that a soft pen tip can be achieved by providing the cover 43. Figure 4 、 Figure 5 The same can be said about the cores 4A, 4B, 4C, 4D, and 4E described above. However, the portion other than the cover 43 can have various configurations. For example, the portion consisting of the main body 41 and the nib 42 can also be composed of a core rod and a protective member covering at least the side surfaces of the core rod. Other configuration examples of the portion other than the cover of the core will be described in detail below.

[0100] <Other structural examples of parts other than the cover portion of the core>

[0101] Figure 6 This is a diagram for explaining another structural example of a portion other than the cover portion of the core body. Figure 6 (A) shows the appearance of the core 4F, Figure 6 (B) shows a cross-sectional view of the core 4F, Figure 6 (C) shows a bottom view of the core 4F. Figure 6 As shown in (A) and (B), the core 4F of this example is composed of a core rod 44 and a protective member 45. It should be noted that the core 4F is actually as Figure 6 As shown by the dotted line in (A), the pen tip portion is partially assembled with a cover portion 43. However, this example also has characteristics in portions other than the cover portion 43, so the following description will focus on portions other than the cover portion.

[0102] Core rod 44 is a conductive rod-shaped member. In this example, core rod 44 is made of a conductive elastomer. Conductive elastomers are made by uniformly mixing conductive particles (such as carbon, metal powder, or metal vapor-deposited powder) into a highly insulating rubber material at a specific ratio, imparting conductivity to the rubber. Consequently, core rod 44 is a flexible, elastic member, achieving a so-called soft writing feel.

[0103] like Figure 6 As shown in FIG. 1B , the core rod 44 has a hemispherical front end 44a that protrudes from the front end of the protective member 45 and forms the pen tip, and a rear end 44c that protrudes from the rear end of the protective member 45 and forms the electrical connection portion. The rod-shaped portion connecting the front end 44a and rear end 44c is the intermediate portion 44b. This intermediate portion 44b has a tapered shape that tapers from the front end 44a toward the rear end 44c.

[0104] like Figure 6As shown in Figures (A) and (B), the protective member 45 covers the side surfaces of the intermediate portion 44b of the mandrel 44, excluding the front end 44a and rear end 44c, to protect the mandrel 44. In this example, the protective member 45 is made of polycarbonate. Polycarbonate is a type of thermoreversible plastic that softens when heated and can be formed into a desired shape, and solidifies when cooled.

[0105] Therefore, when forming the core body 4F, first, a core rod 44 made of a conductive elastomer is molded. Then, by injecting polycarbonate into the same mold relative to the core rod 44 (primary side) to form the protective member 45 (secondary side), this is so-called two-color molding. As a result, a core body 4F having the protective member 45 provided on the side of the middle portion 44b of the core rod 44 can be formed. It should be noted that two-color molding is a molding method for components also called heterogeneous material molding or double molding. And, as Figure 6 As shown in (B), the protection member 45 is composed of three parts having different widths in a direction intersecting the axial direction, namely, a first protection portion 45a, a second protection portion 45b, and a third protection portion 45c.

[0106] like Figure 6 As shown in Figure (B), the first protective portion 45a is located on the tip side of the core 4F. The first protective portion 45a has a tapered shape that tapers toward the tip. Its width, measured in a direction intersecting the axial direction, is greatest within the core 4F at a predetermined range x extending from its rear end toward the tip. However, the width of the predetermined range x, measured in a direction intersecting the axial direction, is slightly shorter than the width (diameter) of the opening of the front cap 22. This ensures that the first protective portion 45a does not become an obstacle, allowing the core 4F to be inserted through the opening of the front cap 22 and assembled within the housing 2.

[0107] Furthermore, when the electronic pen 1 with the core 4F mounted in the housing 2 is used for writing, writing pressure is applied to the core 44 in the axial direction, and force is also applied in the direction opposite to the movement of the electronic pen 1. If this force is strong, the inner wall of the opening of the front cap 22 contacts the outer wall of the first protective portion 45a of the protective member 45 of the core 4F within the specified range x. This prevents excessive load from being applied to the core 44 during writing. This prevents the core 44 from excessively bending, making writing difficult, and prevents damage to the core 44.

[0108] The second protection portion 45b is a portion connected to the rear end of the first protection portion 45a, and is a portion whose width in a direction intersecting the axial direction is shorter than the width of the rear end of the first protection portion 45a and longer than the width of the third protection portion 45c described later in a direction intersecting the axial direction. Figure 6 (A) is viewed from the direction indicated by the arrow Ar. Figure 6As shown in the bottom view (C), the core body 4F is composed of three sections with different diameters. The diameters of the various protection sections are: the first protection section 45a is the longest, the second protection section 45b is the second longest, and the third protection section 45c is the shortest. Furthermore, the second protection section 45b protects the axially center portion of the intermediate section 44b of the core rod 44.

[0109] The third protection portion 45c is a portion connected to the rear end side of the second protection portion 45b, and protects the thinnest portion of the core rod 44. Figure 6 As shown in (B) and (C), the width of the third protection portion 45c in the direction intersecting the axial direction is substantially the same as the width of the rear end portion 44c of the core rod 44 in the direction intersecting the axial direction. Figure 2 As shown, the third protection portion 45 c of the protection member 45 and the rear end portion 44 c of the core rod 44 are inserted into and held by the core holding member 53 of the shaft portion 52 .

[0110] Furthermore, the front end 44a of the core rod 44 protrudes from the protective member 45, thus forming the pen tip, enabling the realization of an electronic pen with a soft writing feel. Furthermore, the rear end 44c of the core rod 44 also protrudes from the protective member 45. This rear end 44c contacts the core retaining member 53, which is formed of a conductive material, and can receive signals from the transmitter 8s. In other words, the rear end 44c of the core rod 44 forms an electrical connection terminal for receiving signals from the transmitter 8s. This allows the signal from the transmitter 8s, generated under the control of the control IC 10, to be transmitted to the position detection sensor via the core rod 44.

[0111] It should be noted that the material of core rod 44 is not limited to conductive elastomers. Core rod 44 can also be formed from resins such as POM (polyoxymethylene or polyacetal) mixed with conductive particles such as metal powder or carbon, or from felt with conductive particles added. Thus, core rod 44 can be formed from a variety of conductive materials. Furthermore, using a relatively soft material such as felt (non-woven fabric) allows for a softer writing feel.

[0112] The material of the protective member 45 is not limited to polycarbonate. The protective member 45 can also be formed using an acrylic resin such as organic glass in combination with polycarbonate. Thus, the protective member 45 can be made of various materials that are thermally reversible, can be formed into the core body 4F together with the mandrel 44 through so-called double molding, and can maintain a certain degree of hardness in a cured state to protect the mandrel 44.

[0113] Thus, by modifying the basic portion of the core body 4F composed of the core rod 44 and the protective member 45 as shown in FIG. Figure 6By attaching cover 43 as shown by the dotted line in (A), a digital pen core with a softer pen tip can be constructed. Core 4F constructed with cover 43 can be used safely with not only conventional tablet devices but also foldable devices. Furthermore, core 4F improves the linearity of the indicated position on the position detection sensor side.

[0114] If used Figure 6 As described above, a core body for an electronic pen can be formed into various shapes consisting of a core rod and a protective member. In this case, the core rod is described as having a front end, a rear end, and a middle portion that tapers from the front end toward the rear end and has a tapered shape, but the invention is not limited to this. It is also possible not to have a tapered shape. Therefore, the core rod can be set to various shapes. In addition, the protective member only needs to protect the middle portion of the core rod. More specifically, the protective member only needs to have a first protective portion that protects the core body against a force applied in a direction opposite to the moving direction during writing, a second protective portion that protects most of the middle portion, and a third protective portion that protects the rear end side of the core rod and forms a fitting portion with the core body retaining member 53.

[0115] Of course, the protective member may be used to cover the entire core rod so as to form the basic portion of the core body and to provide a cover portion on the pen tip portion of the basic portion. Figure 6 The core 4F shown is also capable of being used Figure 4 、 Figure 5 In the manner described above, the cover portions 43A, 43B, 43C, and 43D are provided.

[0116] [Effects of the embodiment]

[0117] The electronic pen 1 of the above-described embodiment includes a buffer mechanism that absorbs the pressure applied to the core 4 when it exceeds 300 gf. This allows for appropriate detection of pressure within the range of 0 gf to less than 300 gf, preventing loads exceeding 300 g from being applied to the operating surface of electronic devices such as tablet PCs. This results in an electronic pen that avoids applying significant pressure to the operating surface, enabling safe use with foldable devices and appropriately detecting pressure.

[0118] Furthermore, by providing a cover portion 43 on the pen tip 42 of the core 4, a softer pen tip with a feel closer to the user's fingertip can be achieved, allowing for secure use with not only conventional tablet devices but also foldable devices. Furthermore, even if the cores 4, 4A, 4B, 4C, 4D, 4E, and 4F are provided with covers 43, 43A, 43B, 43C, and 43D, the parts outside the covers can still function as conventional electronic pen cores. This means that the performance of the electronic pen core remains the same as it did before.

[0119] Furthermore, the covers 43, 43A, 43B, 43C, and 43D are removable from the basic components of the core body, namely, the nib portion (composed of the main body 41, the nib portion 42, etc.) and the nib portion (composed of the core rod 44, the protective member 45, etc.). Thus, even if the covers 43, 43A, 43B, 43C, and 43D deteriorate, they can be replaced, thereby enhancing the durability of the basic components of the core body.

[0120] [Modifications, etc.]

[0121] It should be noted that while the above embodiment describes the setting load of piston spring 54 as 300 gf, this is not limiting. The setting load of piston spring 54 can be adjusted to various values depending on factors such as the strength of the operating surface of the electronic device being used. Furthermore, the shaft 52, core retaining member 53, piston spring 54, and cylinder 55 of the electronic pen 1 in the above embodiment only need to be formed of conductive materials. Various conductive materials can be used as long as they can perform their intended functions.

[0122] Furthermore, the materials constituting the various parts of the cores 4, 4A, 4B, 4C, 4D, 4E, and 4F described in the above-described embodiments are not limited to those described above. Various materials that can fulfill the functions and purposes of each part can be used. In particular, the covers 43, 43A, 43B, 43C, and 43D can be constructed from various materials that are compressible and expandable and that can avoid damaging the display screen of a so-called foldable terminal when it is used as an operating surface. For example, by forming the covers 43, 43A, 43B, 43C, and 43D from a conductive elastomer, it is possible to ensure good conductivity throughout the cores 4, 4A, 4B, 4C, 4D, 4E, and 4F, while also providing a soft writing feel.

[0123] In addition, the assembly method of the cover portion to the pen tip portion is not limited to using Figure 4 、 Figure 5The method described above can be used to assemble the electronic pen in various ways so as to avoid loosening or displacement during use. In addition, the cores 4, 4A, 4B, 4C, 4D, 4E, and 4F can be constructed in various sizes according to the actual use of the electronic pen.

[0124] It should be noted that the dimensions of the nibs 42, 42A, 42B, 42C, and 42D and the dimensions (primarily thickness) of the covers 43, 43A, 43B, 43C, and 43D are determined so that the covers provided on the nibs reach predetermined dimensions when retracted to their limits. This avoids problems such as the covers becoming unnecessarily thick.

[0125] In addition, use Figure 4 (A) The insertion hole 42Aa of the core 4A described above is a holding portion for the insertion portion 43Aa of the cover portion 43A. Figure 4 (B) The groove portion 42Ba described above is a holding portion for the extension portion 43Ba of the cover portion 43B. Figure 4 (C) The extension portion 42Ca described above is a holding portion of the extension portion 43Ca of the cover portion 43C.

[0126] Description of Reference Numerals

[0127] 1...Electronic pen, 2...Casing, 21...Casing body, 22...Front cap, 23...Rear cap, 3...Substrate holder, 3a...Printed substrate placement table, 4, 4A, 4B, 4C, 4D, 4E, 4F...Core, 41, 41A, 41B, 41C, 41D, 41E, 41F...Main body, 42, 42A, 42B, 42C, 42D, 42E, 42F...Pen tip, 43, 43A, 43B, 43C, 43D, 4 3E, 43F…cover portion, 44…core rod, 44a…front end portion, 44aT…rear end surface, 44b…intermediate portion, 44c…rear end portion, 44cT…front end surface, 45…protective member, 45a…first protection portion, 45aT…front end surface, 45b…second protection portion, 45c…third protection portion, 45cT…rear end surface, 5…core unit, 51…unit housing, 51a…front extension portion, 51b…rear extension portion, 52…shaft portion, 5 21…Core holding portion, 521a…Outer protrusion, 522…Piston portion, 53…Core holding member, 54…Piston spring, 55…Cylinder portion, 551…Cylinder main body, 551a…First annular protrusion, 551b…Second annular protrusion, 552…Cylinder connecting portion, 6…Inner housing, 7…Pressure sensing member, 71…Pressure sensing portion housing, 72…Housing cover, 73…Conductive spring, 74…Pressure member holder, 75…Pressure member, 76…First Electrode, 77…spacer, 78…dielectric, 79…second electrode, 8…printed substrate, 8s…transmitting unit, 8d…capacitance detection unit, 9…battery, 91…terminal conductor, 9a…positive terminal, 9b…negative terminal, 92…coil spring terminal, 10…control IC, 11, 12…side switches, 11a, 12a…operating unit, 13…tilt detection electrode, 14…conductive wire, 15…conductive wire, 16…ground ring, SP…gap.

Claims

1. An electronic pen comprising: A rod-shaped core having electrical conductivity; a conductive writing pressure transmitting unit connected to the core body and transmitting the writing pressure applied to the core body to the writing pressure detecting unit; and a transmitting unit, generating a signal to be sent from the core, The electronic pen is characterized in that: The writing pressure transmitting portion is provided with a buffer mechanism for absorbing the writing pressure when a writing pressure exceeding a predetermined value is applied to the core body. The signal from the transmitting unit is supplied to the core body through the writing pressure transmitting unit, and is transmitted to the outside through the core body. The buffer mechanism of the writing pressure transmission unit includes: a cylinder portion connected to the pen pressure detection portion; a shaft portion including a core holding portion and a piston portion inserted into the cylinder portion; a core holding member fixed to the core holding portion of the shaft portion and holding the rear end portion of the core in the core holding portion; and an elastic body, provided between the cylinder portion and the core holding portion of the shaft portion, In a state where the writing pressure applied to the core does not exceed the predetermined value, the distance between the cylinder portion and the shaft portion is maintained constant by the elastic body.

2. The electronic pen according to claim 1, wherein: When the writing pressure applied to the core exceeds the predetermined value, the elastic body contracts and the piston portion of the shaft portion moves into the cylinder portion, causing the core to displace in the direction of the writing pressure and in the axial direction.

3. The electronic pen according to claim 1, wherein: The elastic body is a conductive spring.

4. The electronic pen according to claim 1, wherein The writing pressure transmission portion is configured as a writing pressure transmission unit by accommodating the cylinder portion, the shaft portion having the core holding member provided in the core holding portion, and the elastic body in a predetermined housing.

5. The electronic pen according to claim 1, wherein: The core body includes a main body portion formed in a rod shape and a pen tip portion provided at one end of the main body portion and contacting the operating surface when in use. A cover portion formed of a compressible / expandable material is provided on the outer surface of the pen tip portion on the side that contacts the operating surface during use.

6. The electronic pen according to claim 5, characterized in that The pen tip portion includes a holding portion for holding the cover portion.

7. The electronic pen according to claim 5, characterized in that The cover portion is formed in a sponge shape or a rubber shape.

8. The electronic pen according to claim 5, characterized in that The cover is formed of a conductive material.

9. The electronic pen according to claim 5, wherein: The cover portion is formed of an elastic body having conductivity.

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