Conductive brush pen
The conductive brush pen combines core and reinforcing fibers to enhance reactivity and durability, addressing the limitations of conventional pens by providing a realistic writing experience with high responsiveness and maintaining brush shape.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NAKAMURA SEISAKUSHO KK
- Filing Date
- 2024-11-28
- Publication Date
- 2026-06-09
AI Technical Summary
Conventional conductive brush pens struggle to achieve both high reactivity and a feel similar to a real brush, with issues such as low conductivity at the cross-section, insufficient contact with the panel, and poor durability due to the use of thin conductive fibers.
A conductive brush pen design featuring a shaft with a brush head composed of bundled core conductive fibers and reinforcing fibers, where the core fibers are exposed at the tip and the reinforcing fibers provide support, with a specific area ratio of 10-60% for core fibers and 40-90% for reinforcing fibers, enhancing both reactivity and durability.
The pen provides a realistic writing experience with high responsiveness and durability, allowing for delicate brushstrokes and maintaining the shape of the brush head, thus replicating the feel of a real brush.
Smart Images
Figure 2026093860000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a conductive pen for inputting to a capacitive touch panel.
Background Art
[0002] When a fingertip, a touch pen, etc. touch a capacitive touch panel used in a smartphone, a tablet PC, etc., the capacitance on the panel surface changes, and by detecting the amount of change, the coordinate values of the contact location are calculated. Conventionally, among touch pens (conductive pens) for inputting to such a capacitive touch panel, there are, for example, those having a brush-shaped pen tip as shown in Patent Document 1.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] When writing characters or drawing pictures on a smartphone or a tablet PC using a brush-shaped touch pen (conductive pen), a usage feeling similar to that of actually drawing with a brush and high responsiveness of the input device are expected. However, among conventional conductive pens, there is no pen that can achieve both such a usage feeling and responsiveness. For example, it is difficult to reproduce delicate pen strokes in calligraphy, painting, etc. on the input device.
[0005] Conventional capacitive conductive brush pens use, for example, fibers with a conductive material coating on the outer circumference of a resin fiber, or fibers in which a conductive material is mixed with resin. Conductive fibers with a conductive material coating on the outer circumference of a resin fiber have little conductive material at their cross-section, so when used to make a curved brush, the reactivity is low. In a curved conductive brush pen, the ends of the fibers form a curved shape, and much of the contact with the panel is the cross-section of the fiber, but the contact between the conductive fiber and the panel at the cross-section is insufficient. Fibers in which a conductive material is mixed with resin can reproduce the stiffness of a brush due to the elasticity of the resin, but the reactivity is low because a large amount of conductive material cannot be mixed in. The higher the proportion of conductive material, the higher the conductivity and the higher the reactivity to the input device, but conductive fibers such as carbon fibers are generally thin, around tens of micrometers in diameter, and as a brush, they feel too soft and lack stiffness, the fibers tend to spread outwards, and the durability is poor.
[0006] This invention has been made in view of the above, and its objective is to provide a conductive brush pen that is highly reactive and has a feel similar to that of a real brush. [Means for solving the problem]
[0007] To achieve the above objectives, the invention disclosed herein is: A conductive brush pen used for input to a capacitive input device, The shaft and, The instrument comprises a head body in which multiple fibers of different lengths are bundled together, with the base fixed to the shaft, and the head body having a tapered shape that narrows from the base to the tip, The aforementioned fiber is A conductive fiber having a conductive core and an insulating covering portion covering the outer circumference of the core, wherein the core is exposed at the tip portion which is a cross-section, It includes reinforcing fibers whose diameter is greater than or equal to that of the core conductive fiber and whose main component is an insulating material, The cross-sectional area of the base of the ear head is characterized in that the area ratio of the core conductive fibers is 10 to 60%, and the area ratio of the reinforcing fibers is 40 to 90%.
[0008] According to the above configuration, the conductive brush pen of the present invention provides users with the sensation of actually writing with a brush when drawing or writing on a smartphone or tablet PC using the conductive brush pen of the present invention, while also achieving high responsiveness to the input device. For example, it can reproduce delicate brushstrokes in calligraphy or painting on the input device. The core conductive fibers have high responsiveness to the input device, but are too soft and lack firmness to be used as a brush on their own. However, by using the core conductive fibers and reinforcing fibers in combination with the above area ratio, the reinforcing fibers support the core conductive fibers, giving the brush firmness and reproducing a feel close to that of an actual brush while maintaining good responsiveness. In addition, because the conductive core is exposed at the tip, which is the cross-section of the core conductive fibers, the responsiveness at the tip of the brush head is high, making it possible to reproduce delicate movements of the brush tip on the input device. Furthermore, when used in combination with the reinforcing fibers, the conductive fibers of the present invention are less likely to spread outwards, resulting in high durability.
[0009] The reinforcing fibers are formed by kneading a conductive material with an insulating material, and it is preferable that the conductive material is scattered and exposed on the surface.
[0010] According to the above configuration, by imparting conductivity to the reinforcing fibers, higher responsiveness to input devices can be achieved, and the feel of using the brush can be made closer to that of a real brush.
[0011] Preferably, the core conductive fiber has a diameter of 0.02 to 0.05 mm, and the reinforcing fiber has a diameter of 0.05 to 0.18 mm.
[0012] The above configuration allows for a user experience that more closely resembles that of a real brush.
[0013] Preferably, the tip of the reinforcing fiber has a tapered shape, with the cross-section becoming smaller towards the tip.
[0014] According to the above configuration, since the reinforcing fibers are tapered, the conductive materials scattered on the surface are more likely to come into contact with the input device, and it becomes possible to enhance the reactivity at the tip of the nib body.
[0015] The insulating material constituting the reinforcing fibers is preferably a polyester-based resin.
[0016] According to the above configuration, a more realistic writing feeling similar to that of an actual pen can be obtained, and high durability can also be achieved.
Advantages of the Invention
[0017] As described above, according to the present invention, it is possible to provide a conductive pen with high reactivity and a writing feeling similar to that of an actual pen.
Brief Description of the Drawings
[0018] [Figure 1] It is a front view of a conductive pen according to an embodiment of the present invention. [Figure 2] It is a side view of a conductive pen according to an embodiment of the present invention. [Figure 3] It is a perspective view showing the tip of the core conductive fiber. [Figure 4] It is a side view showing the tip of the core conductive fiber. [Figure 5] It is a side view showing the tip of the core conductive fiber according to another embodiment. [Figure 6] It is a perspective view showing the tip of the reinforcing fiber. [Figure 7] It is a perspective view showing the tip of the reinforcing fiber according to another embodiment. [Figure 8] It is a cross-sectional view showing an example of the manufacturing process of the nib body of the conductive pen. [Figure 9] It is a cross-sectional view showing an example of the manufacturing process of the nib body of the conductive pen. [Figure 10] It is a front view showing the durability of the conductive pen of the comparative example.
Modes for Carrying Out the Invention
[0019] Embodiments of the present invention will be described below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.
[0020] <Embodiment> The conductive brush pen 1 of this disclosure is used for capacitive input devices such as touch panels found in smartphones and tablet PCs. The conductive brush pen 1 is used for input to capacitive input devices.
[0021] Figure 1 is a front view of a conductive brush pen according to an embodiment of the present invention. As shown in Figure 1, the conductive brush pen 1 comprises a shaft 2 and a brush tip 3.
[0022] The shaft 2 is the part that the user grips. The shape of the shaft 2 is not particularly limited, but it has an opening at at least one end in the longitudinal direction. The bristles 3 are inserted into and fixed to the opening of the shaft 2. The shaft 2 is, for example, cylindrical. The shaft 2 is made of a conductive material such as metal and is connected to the bristles 3 so as to be electrically conductive.
[0023] The brush head 3 is made up of numerous fibers of varying lengths bundled together at its base by a metal fastener. The brush head 3 is fixed to the shaft 2 at its base. The brush head 3 has a tapered shape, narrowing from the base to the tip. The tapered shape of the brush head 3 is also called a mountain-shaped shape, as the ends of the fibers are curved to form a mountain-like outer shape. The brush head 3 consists of core conductive fibers 31 and reinforcing fibers 32. The core conductive fibers 31 and reinforcing fibers 32 are uniformly mixed together in the brush head 3.
[0024] Figure 2 is a side view of the conductive brush pen 1 as seen from the tip body 3 side. As shown in Figure 2, the tip body 3 is circular in shape when viewed from the side, and the cross-section of the base of the tip body 3 is also circular. Preferably, the area ratio of the core conductive fibers 31 is 10-60% and the area ratio of the reinforcing fibers 32 is 40-90% in the cross-sectional area of the base of the tip body 3. More preferably, the area ratio of the core conductive fibers 31 is 10-50% and the area ratio of the reinforcing fibers 32 is 50-90% in the cross-sectional area of the base of the tip body 3. Increasing the area ratio of the core conductive fibers 31 is expected to improve responsiveness to input devices, but since the core conductive fibers 31 are generally thin and soft, it is difficult to maintain the shape of the tip body 3 with only the core conductive fibers 31, and the durability is low.
[0025] By setting the area ratio of the core conductive fibers 31 and reinforcing fibers 32 in the cross-sectional area of the base of the brush head 3 as described above, even if the core conductive fibers 31 are thin and soft and it is difficult to use them alone as the brush head 3, the reinforcing fibers 32 support the core conductive fibers 31 and give the brush head 3 rigidity, thus maintaining good responsiveness and reproducing a feel close to that of an actual brush. Furthermore, by using the conductive brush pen 1 in combination with the core conductive fibers 31 and reinforcing fibers 32, the core conductive fibers 31 are less likely to spread outwards, and durability can be increased.
[0026] The core conductive fiber 31 has a conductive core 31a and an insulating covering portion 31b that covers part or all of the outer circumference of the core 31a. The core conductive fiber 31 has an exposed core 31a at least at the tip, which is the cross-section. Because the conductive core 31a is exposed at the tip, which is the cross-section, the responsiveness at the end of the brush head 3 is high, making it possible to reproduce the delicate movements of the brush tip on the input device.
[0027] Figure 3 is a perspective view showing the tip of a core conductive fiber, and Figure 4 is a side view. In the core conductive fiber 31 shown in Figures 3 and 4, an insulating coating 31b covers the entire outer circumference of a conductive core 31a with a circular cross-section. The shape of the core 31a is not limited to having a circular cross-section. Figure 5 is a side view showing the tip of a core conductive fiber according to another embodiment. As shown in Figure 5, the core conductive fiber 31 may have a core 31a with a rectangular cross-section. As shown in Figure 5, the coating 31b covers the long sides on both sides of the core 31a, and the core conductive fiber 31 may have the core 31a exposed in part of its cross-section and outer circumference.
[0028] The core portion 31a is not particularly limited as long as it is a conductive fiber, but for example, it may be a metal fiber, a carbon fiber, or a resin fiber to which a conductive filler has been dispersed to impart conductivity. Examples of conductive fillers include metal-based fillers, metal oxide-based fillers, carbon-based fillers, etc.
[0029] The covering portion 31b coats all or part of the outer circumference of the core portion 31a and is not particularly limited as long as it is an insulating material, but examples include polyamide resins such as nylon 6 and nylon 66, acrylic resins such as polyacrylonitrile, and polyester resins such as polybutylene terephthalate.
[0030] The raw materials, formulation, and manufacturing methods of the core portion 31a and the covering portion 31b are not particularly limited, and known conductive fibers with a conductive core and an insulating covering portion can be used as the core conductive fiber 31. As a core-sheath type core conductive fiber 31 as shown in Figures 3 and 4, for example, Corebrid® manufactured by Mitsubishi Chemical Corporation can be used. As a core conductive fiber 31 as shown in Figure 5, for example, Beltron® #931, #961, #B31, and #GC3 manufactured by KB Seiren Co., Ltd. can be used. The diameter of the core conductive fiber is preferably 0.02 to 0.05 mm, more preferably 0.03 to 0.04 mm, from the viewpoint of the reactivity of the input device and manufacturing efficiency. It is also possible to replace a part of the core conductive fiber 31 with conductive fibers such as carbon fiber.
[0031] Figure 6 is a perspective view showing the tip of the reinforcing fiber. As shown in Figure 6, it is preferable that the tip of the reinforcing fiber 32 has a tapered shape, with the cross-section becoming smaller towards the tip. Figure 7 is a perspective view showing the tip of the reinforcing fiber of another embodiment. As shown in Figure 7, the reinforcing fiber 32 has good usability and responsiveness even if the tip is not tapered, but the tapered shape as in Figure 6 makes it easier for the conductive material scattered on the surface to come into contact with the input device, further enhancing the responsiveness of the tip of the brush head 3 and making it possible to obtain a delicate usability closer to that of an actual brush.
[0032] The reinforcing fiber 32 mainly consists of an insulating material 32a. Here, "main component" means that when the total reinforcing fiber 32 is 100 parts by mass, at least 60 parts by mass are the insulating material. The reinforcing fiber 32 is formed by kneading and dispersing a conductive material 32b into the main component insulating material 32a, and it is preferable that the conductive material 32b is scattered and exposed on the surface. The reinforcing fiber 32 does not necessarily have to contain the conductive material 32b, but by dispersing the conductive material 32b and imparting conductivity to the reinforcing fiber 32, a higher responsiveness to the input device can be obtained, and the feel of use can be made closer to that of an actual brush. When the reinforcing fiber 32 contains the conductive material 32b, it is preferable that the area ratio of the core conductive fiber 31 in the cross-sectional area of the base of the brush head 3 is 10 to 60%, and the area ratio of the reinforcing fiber 32 is 40 to 90%. When the reinforcing fibers 32 do not contain conductive material 32b, it is preferable that the area ratio of the core conductive fibers 31 in the cross-sectional area of the base of the ear head 3 is 30-60%, and the area ratio of the reinforcing fibers 32 is 40-70%.
[0033] The insulating material 32a, which is the main component of the reinforcing fiber 32, is, for example, a polyester resin such as polybutylene terephthalate. The conductive material 32b, which is kneaded into the insulating material 32a, is not particularly limited, but for example, it is a carbon-based filler such as carbon black or graphite, or a metal oxide-based filler such as tin oxide, zinc oxide, or indium oxide. The mixing ratio of the insulating material 32a and the conductive material 32b is not particularly limited, and known conductive fibers that have been kneaded with a conductive material to impart conductivity can be used as the reinforcing fiber 32. The diameter of the reinforcing fiber 32 is greater than or equal to that of the core conductive fiber 31. From the viewpoint of improving the feel and durability of the conductive brush pen, the diameter of the reinforcing fiber 32 is preferably 0.05 to 0.18 mm, more preferably 0.10 to 0.15 mm.
[0034] <Manufacturing method for conductive brush pens> An example of a manufacturing method for the conductive brush pen of this disclosure will be described. First, the core conductive fibers and reinforcing fibers are measured and taken such that the area ratio of the core conductive fibers is 10-60% and the area ratio of the reinforcing fibers is 40-90% in the cross-sectional area of the base of the brush head. The measured core conductive fibers and reinforcing fibers are uniformly mixed using a fiber mixing machine to create a fiber bundle A. Next, as shown in Figure 8, a vase X with a curved recess is used, and the tip of the fiber bundle A is inserted into the recess of the vase X and vibrated to form the curved shape. The base of the fiber bundle A with the curved shape is fixed with a metal fastener 33 to create the brush head 3. When the fastener 33 of this brush head 3 is fitted into the opening of the shaft 2 and fixed, a conductive brush pen 1 is obtained.
[0035] Figures 9 and 10 show other examples of the manufacturing process for the brush head. The brush head 3 of the conductive brush pen 1 can also be formed by extrusion instead of the molding method shown in Figure 8. Specifically, the base ends of the fiber bundle A, obtained by mixing the core conductive fibers and reinforcing fibers, are aligned, and the entire fiber bundle is moistened with water. The water-moistened fiber bundle A is inserted into a cylindrical mold Y. Next, as shown in Figure 9, a poking rod Z with a mountain-shaped tip is prepared, and the tip of the poking rod Z is inserted into the mold Y toward the base end of the fiber bundle A. With the poking rod Z inserted, the base end of the poking rod Z is struck several times against a flat surface to form the mountain shape, and the brush head 3 is manufactured.
[0036] The method for manufacturing the conductive brush pen 1 is not limited to the above, and known methods for manufacturing brushes can be applied.
[0037] The conductive fiber core, in which a conductive core is covered with an insulating coating, can be partially replaced with conductive fibers such as carbon fibers, as long as the effects of the present invention are not impaired. For example, Teijin's Tenax® can be used as the conductive fiber. When a portion of the conductive fiber core is replaced with carbon fibers, it is preferable to place the conductive fibers inside the tip body and perform molding by extrusion in order to prevent them from spreading outwards. [Examples]
[0038] The conductive brush pen of this disclosure will be described based on examples and comparative examples. The core conductive fibers and reinforcing fibers constituting the brush head were mixed in various area ratios in the cross-sectional area of the base of the brush head, and the feel of use as a conductive brush pen and the responsiveness of input devices were evaluated. In Examples 1 and 2 and Comparative Examples 1 to 3, the same type of core conductive fibers and reinforcing fibers were used, with only the area ratio of the core conductive fibers and reinforcing fibers in the cross-sectional area of the base of the brush head differing. In Examples 1 and 2 and Comparative Examples 1 to 3, reinforcing fibers containing conductive material were used, but in Examples 3 and 4, reinforcing fibers without conductive material were used. Details of the raw materials are shown below.
[0039] Core conductive fiber: 0.03 mm in diameter, carbon fiber core, nylon resin coating (Beltron® #931, manufactured by KB Seiren Co., Ltd.) Reinforcement fibers (including conductive material): Diameter 0.10-0.15 mm, insulating material: polybutylene terephthalate, conductive material: carbon black, tapered tip shape. Reinforcement fibers (excluding conductive material): 0.10-0.15 mm in diameter, insulating material: polybutylene terephthalate, tapered tip.
[0040] Table 1 shows the fiber composition of the brush tip section of Examples 1-5 and Comparative Examples 1-3, along with their evaluation results. Each conductive brush pen was evaluated by a total of seven employees and related personnel of the applicant for its responsiveness to an input device and its feel as a brush. A tablet-type touch panel was used as the input device, and a general drawing application was launched to evaluate the responsiveness and feel of the conductive brush pen. For responsiveness, those that were perceived as good were rated "A," those that were perceived as not bad were rated "B," and those that were perceived as not good were rated "C." Similarly, for feel, those that were perceived as good were rated "A," those that were perceived as not bad were rated "B," and those that were perceived as not good were rated "C." Each of the seven individuals evaluated the conductive brush pen of each example and comparative example. Since 5 to 7 people gave the same evaluation, Table 1 shows the evaluation of the majority.
[0041] [Table 1]
[0042] (Comparative Example 1) Comparative Example 1, which consisted only of reinforcing fibers containing conductive material and lacked a core conductive fiber, showed poor responsiveness and usability, making it impractical as a conductive brush pen.
[0043] (Example 1) In Example 1, where the area ratio of the core conductive fibers was 10% and the area ratio of the reinforcing fibers containing conductive material was 90%, both responsiveness and usability were good, and it was possible to perform delicate brushwork similar to that of using an actual brush.
[0044] (Example 2) In Example 2, where the area ratio of the core conductive fibers was 10% and the area ratio of the reinforcing fibers without conductive material was 90%, the responsiveness of the input device was inferior to that of Example 1. However, a feel similar to that of an actual brush was obtained, similar to Example 1, and it was determined that there were no problems in terms of practicality as a conductive brush pen.
[0045] (Example 3) In Example 3, where the area ratio of the core conductive fibers was 50% and the area ratio of the reinforcing fibers containing conductive material was 50%, both the responsiveness and usability were good, similar to Example 1, and it was possible to perform delicate brushwork similar to that of using an actual brush.
[0046] (Example 4) In Example 4, where the area ratio of the core conductive fibers was 50% and the area ratio of the reinforcing fibers without conductive material was 50%, the responsiveness of the input device was inferior to that of Example 3. However, similar to Examples 1 and 3, a feel close to that of an actual brush was obtained, and it was determined that there were no problems in terms of practicality as a conductive brush pen.
[0047] (Example 5) In Example 5, where the area ratio of conductive fibers in the core was 60% and the area ratio of reinforcing fibers containing conductive material was 40%, both responsiveness and usability were inferior compared to Examples 1 and 3. However, it was determined that there were no problems in terms of practicality as a conductive brush pen. It was thought that the decrease in responsiveness and usability was due to the increased proportion of conductive fibers in the core, which made the brush head softer.
[0048] (Comparative Example 2) In Comparative Example 2, where the area ratio of the core conductive fibers was 90% and the area ratio of the reinforcing fibers containing conductive material was 10%, both the responsiveness and usability were poor, making it impractical as a conductive brush pen. It is thought that the increased proportion of core conductive fibers made the brush head too soft and difficult to use, significantly reducing operability and thus lowering responsiveness. Furthermore, as shown in Figure 10, in the conductive brush pen of Comparative Example 2, the core conductive fibers 31 tended to bend outward from the brush head 3, making it difficult to maintain the shape of the brush head 3, raising concerns about durability.
[0049] (Comparative Example 3) Comparative Example 3, which consisted only of conductive fibers in the core and lacked reinforcing fibers, showed poor responsiveness and usability, making it impractical as a conductive brush pen. Because the brush head was formed solely from conductive fibers in the core, the brush head was too soft and difficult to use, resulting in significantly reduced operability, which likely contributed to the decreased responsiveness. Furthermore, as shown in Figure 10, the conductive brush pen of Comparative Example 3 was prone to the conductive fibers 31 in the core bending outward from the brush head 3, making it difficult to maintain the shape of the brush head 3 and raising concerns about durability.
[0050] Theoretically, reactivity is expected to increase in proportion to the area ratio of conductive fibers in the core. However, when the area ratio of conductive fibers in the core exceeded 90%, both operability and reactivity decreased significantly. When the area ratio of conductive fibers in the core exceeded 50%, the stiffness of the brush head gradually decreased, the operability as a brush deteriorated, and consequently, the reactivity worsened. In particular, when the area ratio of conductive fibers in the core exceeded 90%, the decrease in reactivity due to the significant decrease in usability and operability outweighed the improvement in reactivity due to the increased area ratio of conductive fibers in the core, resulting in poor reactivity. From these results, it can be concluded that in order to obtain a conductive brush pen that achieves both high reactivity and usability, it is not simply a matter of including a large amount of conductive fibers in the core, but rather it is necessary to find an optimal balance between the area ratio of conductive fibers in the core and reinforcing fibers. [Explanation of symbols]
[0051] 1. Conductive brush pen 2-axis body 3. Ear of grain head 31 Core conductive fibers 31a Core 31b Covering 32 Reinforcement fibers 32a Insulating material 32b Conductive materials 321 Tip
Claims
1. A conductive brush pen used for input to a capacitive input device, The shaft and, The instrument comprises a head body in which multiple fibers of different lengths are bundled together, with the base fixed to the shaft, and the head body having a tapered shape that narrows from the base to the tip, The aforementioned fiber is A conductive fiber having a conductive core and an insulating covering portion covering the outer circumference of the core, wherein the core is exposed at the tip portion which is a cross-section, It includes reinforcing fibers whose diameter is greater than or equal to that of the core conductive fiber and whose main component is an insulating material, A conductive brush pen in which, in the cross-sectional area of the base of the brush head, the area ratio of the core conductive fibers is 10 to 60%, and the area ratio of the reinforcing fibers is 40 to 90%.
2. The conductive brush pen according to claim 1, wherein the reinforcing fibers are formed by kneading a conductive material with an insulating material, and the conductive material is scattered and exposed on the surface.
3. The conductive brush pen according to claim 1 or 2, wherein the core conductive fiber has a diameter of 0.02 to 0.05 mm, and the reinforcing fiber has a diameter of 0.05 to 0.18 mm.
4. The conductive brush pen according to claim 3, wherein the tip of the reinforcing fiber has a tapered shape, with the cross-section becoming smaller towards the tip.
5. The conductive brush pen according to claim 4, wherein the insulating material constituting the reinforcing fibers is a polyester resin.