electromagnetic pen

Abstract

The present invention relates to an electromagnetic pen. The electromagnetic pen comprises: a pen barrel, a first pen tip rod and a second pen tip rod, respectively disposed at both ends of the pen barrel; a first inductor and a second inductor, respectively disposed at both ends of the pen barrel; and a main capacitor disposed within the pen barrel. The first inductor and the second inductor are connected in series and then connected to the main capacitor to form a resonant circuit. The first pen tip rod is telescopically mounted at one end of the pen barrel, and the inductance value of the first inductor changes in response to the telescopic displacement of the first pen tip rod along the pen barrel. The electromagnetic pen of the present invention has inductor coils at both ends of the pen barrel, so both ends can be used on an electromagnetic screen.

Description

Technical Field

[0001] The present invention relates to the field of touch technology, and in particular to an electromagnetic pen. Background Art

[0002] Traditional electromagnetic pen input devices only have a single inductive coil located at one end of the electromagnetic pen body. Therefore, when the electromagnetic pen is in use, the pen tip can only perform the function of a pen on the electromagnetic input screen, generally showing handwriting. Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the existing electromagnetic pen circuit principle. Figure 2 The block diagram of the working principle of the existing electromagnetic screen. The traditional electromagnetic pen only has a coil inductor L at one end of the electromagnetic pen and a capacitor C that forms a resonant circuit with it. The resonant frequency When the electromagnetic pen slides across the electromagnetic screen, it generates a signal related to the resonant frequency. The electromagnetic screen is equipped with an antenna matrix. During operation, the antenna matrix receives the signal generated by the electromagnetic pen. This signal is processed by a series of components, including a multiplexer, amplification and filtering circuits, and a main control unit, and then transmitted to the computer connected to the electromagnetic screen. This information is then generated, including the coordinates of the electromagnetic pen and the pressure sensitivity.

[0003] Traditional electromagnetic pens only have an inductor coil at the front end, so only the front end can be used on the electromagnetic screen. The resonant frequency is generated by a single set of coil inductance and capacitance, and the same pen can only realize the functions represented by a single pen type, such as ink flow. When the pen tip is pressed, because only a single-tip pen tip is available, the resonant frequency changes in the forward and reverse directions only in one direction. For example, the resonant frequency increases in the forward direction, or decreases in the reverse direction, which is generally used to express changes in handwriting thickness. The inability to achieve two forward and reverse resonant frequency changes in the same pen body limits the user's functionality, preventing users from experiencing more functional variability with the same pen body, and therefore urgently needs improvement. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide an electromagnetic pen, both ends of which can be used on an electromagnetic screen.

[0005] To achieve the above objectives, the present invention provides an electromagnetic pen, comprising: a pen barrel, a first pen tip rod and a second pen tip rod, respectively disposed at either end of the pen barrel; a first inductor and a second inductor, respectively disposed at either end of the pen barrel; and a main capacitor disposed within the pen barrel, wherein the first and second inductors are connected in series to the main capacitor to form a resonant circuit; the first pen tip rod is retractably mounted at one end of the pen barrel, and the inductance of the first inductor changes in response to the telescopic displacement of the first pen tip rod along the pen barrel. By providing inductors at both ends, both ends can be used on an electromagnetic screen, and the resonant frequency changes by varying the inductance of the first inductor.

[0006] The invention further includes a first elastic component, the first inductor including a first iron powder core, a first coil, and a first winding frame; the first winding frame is fixed to the front end of the pen barrel, the first coil is wound on the first winding frame, the first iron powder core is inserted into the hollow hole of the first winding frame and can move back and forth along the hollow hole of the first winding frame; the front end of the first pen tip rod is located outside the pen barrel, the tail end of the first pen tip rod transmits the pressure from the front end to the first iron powder core to cause it to move inward along the hollow hole of the first winding frame, and the first elastic component compresses in response to the inward movement of the first iron powder core to generate an elastic force that causes the first iron powder core to move outward. The first inductor achieves a change in resonant frequency in one direction through the cooperation of the first elastic component and the first iron powder core.

[0007] Wherein, fixed limiting plates are respectively provided at both ends of the first winding frame to fix the first winding frame in the pen holder.

[0008] Among them, it also includes a second elastic component, a second elastic component limiting plate, and a first elastic component limiting plate. The second elastic component is arranged between the second elastic component limiting plate and the front end surface of the first iron powder core. The tail end of the first pen tip rod passes through the hollow hole of the second elastic component limiting plate and through the hollow hole of the second elastic component and is inserted into the central hole at the front end of the first iron powder core. The tail end of the first pen tip rod and the central hole at the front end of the first iron powder core are tightly matched. The first elastic component is arranged between the rear end surface of the first iron powder core and the first elastic component limiting plate.

[0009] Wherein, the second pen tip rod is fixedly mounted on the other end of the pen holder. In this case, the second inductor can be a fixed inductor.

[0010] The second pen tip rod is retractably mounted at the other end of the pen barrel, and the inductance of the second inductor changes in response to the extension and retraction of the second pen tip rod along the pen barrel. The second inductor can be similar in form to the first inductor, and changes in the second inductor can affect the resonant frequency.

[0011] The second inductor includes a second iron powder core and a second coil, and the second coil is wound around the cylindrical surface of the second iron powder core; the second pen tip rod is fixedly mounted on the other end of the pen barrel, the front end of the second pen tip rod is located outside the pen barrel, and the tail end passes through the other end of the pen barrel through the hollow center of the second iron powder core and the hollow hole of the first elastic component, and the center hole at the rear end of the first iron powder core and the tail end of the second pen tip rod are tightly fitted. At this time, the second inductor is a fixed inductor. The first inductor can achieve a resonant frequency change in another direction through the cooperation of the second elastic component and the first iron powder core.

[0012] Wherein, fixed limiting plates are respectively provided at both ends of the second iron powder core to fix the second iron powder core in the pen holder.

[0013] The resonant circuit also includes at least one branch capacitor connected in parallel with the main capacitor, and the branch capacitor is provided with a switch to control whether it is connected in parallel to the main capacitor. By changing the capacitance in the resonant circuit, the resonant frequency can be changed, and different resonant frequencies can be pre-set to different functions.

[0014] Wherein, the first elastic component and the second elastic component are springs.

[0015] In summary, both ends of the electromagnetic pen body of the present invention are provided with inductive coils, so both ends can be used on the electromagnetic screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] In the accompanying drawings,

[0018] Figure 1 This is a schematic diagram of the circuit principle of an existing electromagnetic pen;

[0019] Figure 2 This is a block diagram of the working principle of the existing electromagnetic screen;

[0020] Figure 3 This is a schematic diagram of the internal structure of a preferred embodiment of the electromagnetic pen of the present invention;

[0021] Figure 4 A schematic diagram of inductance variation of a preferred embodiment of the electromagnetic pen of the present invention;

[0022] Figure 5 This is a schematic diagram of the circuit principle of a preferred embodiment of the electromagnetic pen of the present invention. DETAILED DESCRIPTION

[0023] See also Figure 3, which is a schematic diagram of the internal structure of a preferred embodiment of the electromagnetic pen of the present invention. In this preferred embodiment, the entire electromagnetic pen mainly includes the following components: a pen barrel 30, a first pen tip rod, also known as a pen tip rod, specifically the front pen tip rod 10 in this embodiment, a second elastic component limit plate, specifically the front spring limit plate 11 in this embodiment, a second elastic component, specifically the front spring 12 in this embodiment, a first inductor, specifically the front variable inductor (VFL) 1 in this embodiment, a VFL fixed limit plate 13, a first elastic component, specifically the rear spring 14 in this embodiment, a first elastic component limit plate, specifically the rear spring limit plate 15 in this embodiment, a second pen tip rod, also known as a pen tip rod, specifically the rear pen tip rod 20 in this embodiment, a second inductor, specifically the rear fixed inductor (RL) 2 in this embodiment, a main (resonant) capacitor C, and an RL fixed limit plate 16. The surface of the pen barrel 30 is for the user to hold. The pen barrel 30 contains the main components of the electromagnetic pen. All limit plates are set at fixed preset positions within the pen barrel 30.

[0024] The front end of the front nib rod 10 is positioned outside the pen barrel 30, and the rear end passes through the hollow hole of the front spring stop plate 11 and the hollow hole of the front spring 12, and is inserted into the central hole at the front end of the first movable iron powder core (i.e., iron powder core 100) of the front variable inductor (VFL) 1. The rear end of the front nib rod 10 and the central hole at the front end of the iron powder core 100 are tightly fitted. The front spring 12 is positioned between the front spring stop plate 11 and the front end surface of the iron powder core 100 at the center of the front variable inductor (VFL) 1.

[0025] The front variable inductor (VFL) 1 is composed of an iron powder core 100 with central holes at both ends, a first winding frame, namely the winding frame 101, and a first coil, namely the coil 102, wound on the winding frame 101. The two ends of the winding frame 101 are respectively fixed by VFL fixed limit plates 13. The iron powder core 100 is arranged in the hollow through hole of the winding frame 101, and the iron powder core 100 can move forward and backward (up and down). The front end of the iron powder core 100 is in contact with the surface of the front spring 12, the central hole at the front end of the iron powder core 100 is tightly fitted with the front pen tip rod 10, the rear end of the iron powder core 100 is in contact with the surface of the rear spring 14, the central hole at the rear end of the iron powder core 100 is tightly fitted with the tail end of the rear pen tip rod 20, and the lead of the coil 102 is connected in series with the rear fixed inductor (RL) 2.

[0026] The rear spring 14 is positioned between the rear end surface of the front variable inductor (VFL) 1 and the rear spring stop plate 15. A rear pen tip rod 20 passes through the hollow hole of the rear spring 14. The rear pen tip rod 20 extends from the rear of the pen barrel 30 through the central hollow second iron powder core (i.e., iron powder core 200) of the rear fixed inductor (RL) 2 and through the hollow hole of the rear spring stop plate 15. The rear end of the rear pen tip rod 20 fits snugly within the central hole of the rear end of the central iron powder core 100 of the front variable inductor (VFL) 1.

[0027] The second coil of the rear fixed inductor (RL) 2, namely the coil 201, is directly wound on the cylindrical surface of the iron powder core 200. The lead of the coil 201 is connected in series with the front variable inductor (VFL) 1. The hollow hole provided in the iron powder core 200 is for the rear pen tip rod 20 to pass through. The two ends of the iron powder core 200 are respectively fixed by the RL fixed limit plate 16 of the rear fixed inductor (RL) 2.

[0028] See also Figure 4 , which is a schematic diagram of the inductance variation of a preferred embodiment of the electromagnetic pen of the present invention. For the front variable inductor (VFL) 1, when the iron powder core 100 is pushed upward, its center point shifts upward, causing the VFL to decrease and the resonant frequency to rise. When the iron powder core 100 is pushed downward, its center point shifts downward, causing the VFL to increase and the resonant frequency to decrease.

[0029] See also Figure 5 , which is a schematic diagram of the circuit principle of a preferred embodiment of the electromagnetic pen of the present invention. This embodiment is equipped with two inductors, a front variable inductor (VFL) 1 and a rear fixed inductor (RL) 2, which are respectively placed at the two ends of the pen barrel 30. VFL represents the inductance value of the front variable inductor (VFL) 1, RL represents the inductance value of the rear fixed inductor (RL) 2, and C represents the capacitance value of the main (resonant) capacitor C. In this embodiment, the resonant frequency of the resonant circuit is

[0030] Combine Figure 3 It can be seen that in this embodiment, when the front pen tip rod 10 is pressed downward (pushed inward), the front pen tip rod 10 will push the iron powder core 100 of the front variable inductor (VFL) 1 to move inward, and the inductance value changes due to the change in the position of the center point of the length of the iron powder core 100 at the center point of the coil 102, thereby changing the resonant frequency of the resonant circuit formed by (VFL+RL) and C.

[0031] When the center point of the iron powder core 100 is originally set to the inside (right) of the center point of the coil 102 of the front variable inductor (VFL) 1, when the front pen tip rod 10 is pressed downward (pushed inward), the iron powder core 100 moves inward (to the right), and the center point of the iron powder core 100 is offset further inward (to the right), causing the inductance value of the front variable inductor (VFL) 1 to decrease and thus causing the resonant frequency of (VFL+RL) and C to increase. The more inward the force is pushed, the higher the resonant frequency is, which means that the greater the force applied to the front pen tip rod 10, the higher the resonant frequency is, and it is directly proportional.

[0032] The iron powder core 100 of the current variable inductor (VFL) 1 is forced to move inward, pushing the compressed rear spring 14 inward. When the external force applied to the front pen tip 10 is removed or reduced, the rear spring 14 pushes the iron powder core 100 back outward (to the left). When the force becomes smaller, the center point of the iron powder core 100 and the coil 102 are closer, the inductance value VFL increases, and the resonant frequency of (VFL+RL) and C will decrease.

[0033] When the rear pen tip rod 20 is pushed into the pen barrel 30 by force, the rear pen tip rod 20 moves inward, thereby pushing the iron powder core 100 of the front variable inductor (VFL) 1 to move to the left. The midpoint of the iron powder core 100 of the front variable inductor (VFL) 1 is closer to the center point of the coil 102, making the inductance value VFL larger, and thus the resonant frequency of (VFL+RL) and C decreases. The greater the force applied, the greater the inductance value VFL, and thus the lower the resonant frequency, showing an inverse proportional performance. When the rear pen tip rod 20 is pushed inward, it pushes the iron powder core 100 of the front variable inductor (VFL) 1 to the left and compresses the front spring 12. When the external force is reduced or removed, the front spring 12 will rebound and push the iron powder core 100 of the front variable inductor (VFL) 1 back inward (to the right). The center point of the iron powder core 100 of the front variable inductor (VFL) 1 and the center point of the coil 102 will be relatively farther away, the inductance value VFL will decrease, and the resonant frequency of (VFL+RL) and C will increase.

[0034] In this embodiment, the main (resonant) capacitor C that resonates with the front variable inductor (VFL) 1 and the rear fixed inductor (RL) 2 can be provided with several branch capacitors C1, C2, ..., CN connected in parallel, and each capacitor is provided with its own switch SW1, SW2, ..., SWN. By changing the state of the switch, the branch of the main (resonant) capacitor C can be selected and connected in a permutation and combination manner. The resonant frequency changes due to the capacitance value of the branch capacitors connected in parallel in each permutation and combination and the original main (resonant) capacitor C being increased in parallel. The resonant frequency Thus, the starting value of the basic resonant frequency can be changed, and multiple sections of resonant frequency can be formed. By setting switches SW1, SW2, ... SWN on the pen barrel of the electromagnetic pen to connect the various parallel capacitors that change the main resonant frequency, as long as different switches are pressed, different capacitors that change the main resonant frequency are connected in parallel to the original main (resonant) capacitor C, then the main resonant frequency band value on the same pen at that time will change, the ID value can also be changed accordingly, or the different functional performances of the electromagnetic pen can also be changed, thus forming a method for conveniently changing the pen ID value and functional characteristics.

[0035] In this embodiment, a pen body is designed with an inductor coil and an electromagnetic pen tip (head) at both ends. Both pen tips (heads) can change the resonant frequency, that is, the resonant frequency of the electromagnetic pen when it is working. Moreover, when the pen tips at both ends of the pen body are used (subject to pressure), the proportional direction of the change in the resonant frequency is different. When the pen tips at both ends of the pen body are pressed, the resonant frequency value of one end changes upward, while that of the other end changes downward.

[0036] By measuring the rise and fall of the resonant frequency at the tips of the pen when in use, it is possible to distinguish two different pens or different functionalities. For example, there is an eraser with variable erased stroke size, an airbrush with a wider or farther spray range, and a watercolor pen with variable distance rendering. It is very easy to use and can be flexibly changed by using it with an APP.

[0037] By adjusting the capacitance of the resonant capacitor, the main resonant frequency can be changed. Each different main resonant frequency represents a different ID value. When used with the front and back nibs of each pen, they can represent two ID values. By changing the preset capacitance value, the electromagnetic pen designed by this invention can display more and more exciting functions.

[0038] Therefore, the present invention can be used on the same pen, by providing a button on the pen barrel and inductive coils at the front and rear ends, so that the frequency of the pen tips at the front and rear ends changes upward and downward differently when the pen tips are used, to arrange and combine many pens with different IDs or perform unique functions of the pen, which is extremely convenient.

[0039] In summary, both ends of the electromagnetic pen body of the present invention are provided with inductive coils, so both ends can be used on the electromagnetic screen.

[0040] As described above, for ordinary technicians in this field, various other corresponding changes and modifications can be made based on the technical solutions and technical concepts of the present invention, and all these changes and modifications should fall within the scope of protection of the claims attached to the present invention.

Claims

1. An electromagnetic pen, characterized in that: include: A pen holder, a first pen tip rod and a second pen tip rod respectively provided at both ends of the pen holder, a first inductor and a second inductor respectively provided at both ends of the pen holder, and a main capacitor provided in the pen holder, the first inductor and the second inductor being connected in series and then connected to the main capacitor to form a resonant circuit, the first pen tip rod being telescopically mounted at one end of the pen holder, and the inductance value of the first inductor changing in response to the telescopic displacement of the first pen tip rod along the pen holder; The electromagnetic pen further includes a first elastic component, the first inductor includes a first iron powder core, a first coil, and a first winding frame; the first winding frame is fixed to the front end of the pen barrel, the first coil is wound on the first winding frame, the first iron powder core is inserted into the hollow hole of the first winding frame and can move back and forth along the hollow hole of the first winding frame, the front end of the first pen tip rod is arranged outside the pen barrel, the tail end of the first pen tip rod transmits the pressure from the front end to the first iron powder core to move inward along the hollow hole of the first winding frame, and the first elastic component is compressed in response to the inward movement of the first iron powder core to generate an elastic force that causes the first iron powder core to move outward; The electromagnetic pen further includes a second elastic component, a second elastic component limiting plate, and a first elastic component limiting plate, wherein the second elastic component is arranged between the second elastic component limiting plate and the front end surface of the first iron powder core, the tail end of the first pen tip rod passes through the hollow hole of the second elastic component limiting plate and the hollow hole of the second elastic component and is inserted into the central hole at the front end of the first iron powder core, and the tail end of the first pen tip rod and the central hole at the front end of the first iron powder core are tightly fitted together, and the first elastic component is arranged between the rear end surface of the first iron powder core and the first elastic component limiting plate; The second inductor includes a second iron powder core and a second coil, and the second coil is wound on the cylindrical surface of the second iron powder core; the second pen tip rod is fixedly installed on the other end of the pen barrel, the front end of the second pen tip rod is arranged outside the pen barrel, and the tail end passes through the other end of the pen barrel through the hollow center of the second iron powder core and the hollow hole of the first elastic component, and the center hole at the rear end of the first iron powder core and the tail end of the second pen tip rod are tightly fitted.

2. The electromagnetic pen according to claim 1, wherein: Fixed limiting plates are respectively provided at both ends of the first winding frame to fix the first winding frame in the pen holder.

3. The electromagnetic pen according to claim 1, wherein: Fixed limiting plates are respectively provided at both ends of the second iron powder core to fix the second iron powder core in the pen holder.

4. The electromagnetic pen according to claim 1, wherein: The resonant circuit further includes at least one branch capacitor connected in parallel with the main capacitor, and the branch capacitor is provided with a switch to control whether it is connected in parallel to the main capacitor.

5. The electromagnetic pen according to claim 1, wherein: The first elastic component and the second elastic component are springs.

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