JP2024007675A - Input apparatus for touch sensor and input system to touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an input system that allow input to a touch sensor with a brush without compromising traditional characteristics of the brush.

SOLUTION: A system is for inputting to an input screen of a computer including a touch sensor using an input apparatus. The input apparatus includes a brush neck 60 and a shaft 70. The brush neck 60 is composed of bristles, which are insulators, the shaft 70 is an insulator, and conductive paint 80 is applied to an outside of the shaft 70. The input apparatus impregnates the brush neck 60 (62) with conductive liquid to input on the input screen.

SELECTED DRAWING: Figure 16

COPYRIGHT: (C)2024,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a display device, and particularly to a configuration that allows input using a brush in a display device having a touch sensor or a touch panel.

A method of inputting information by touching the surface of a display device with a finger or the like has become common in so-called smartphones and tablet display devices. Although there is a method of disposing a touch panel above the display area, liquid crystal display devices and the like have been developed that have a touch panel function built into the liquid crystal display panel.

Patent Document 1 describes a system in which a touch panel function is built into a liquid crystal display panel. In this method, one electrode of the touch panel is arranged outside the counter substrate, and a common electrode in the liquid crystal display panel is used as the other electrode of the touch panel.

On the other hand, in addition to the human finger, a method of using a stylus pen as an input means to a touch panel has also become common. Patent Documents 2 to 6 describe various stylus pen configurations.

JP 2016-1233 Publication JP2014-52881A Japanese Patent Application Publication No. 2015-84182 Unexamined Japanese Patent Publication No. 2015-5106 JP2014-95978A WO2013/057862

A brush with a special configuration has been developed for inputting a brush (hereinafter simply referred to as a brush) to a touch panel. This uses conductive bristles for the tip (neck) of the brush, which is quite different from the traditional tip. That is, the tips of traditional brushes are made from processed animal hair, and traditional brushes are manufactured by applying processes to this animal hair.

A stylus pen with conductive bristles like this can be used as an input device for simple brush strokes, but when a calligrapher writes calligraphy on a touch panel, a stylus pen like this with conductive bristles is used. Traditional brushes are preferred, rather than those using brushes. It is unclear whether it is possible to write calligraphy as a digital art using brushes other than traditional calligraphy brushes. For calligraphers, selecting a brush is also part of their skill.

On the other hand, when schoolchildren and adults practice calligraphy, it is assumed that they use traditional brushes. In other words, if we do not use traditional brushes, the purpose of practicing calligraphy will change. There is also a demand for practicing calligraphy on a touch panel without using ink, inkstones, or paper. If you want to practice calligraphy on a touch panel, the input device you use needs to have a configuration as close to a traditional brush as possible. Otherwise, you won't be able to practice calligraphy.

An object of the present invention is to realize an input device for a touch panel that has a configuration similar to a traditional brush.

The present invention is intended to overcome the above problems, and representative means are as follows.

(1) An input device for a touch sensor having a head and a shaft, wherein the head is made of hair that is an insulator, the shaft is an insulator, and the outside of the shaft is made of conductive material. An input device for a touch sensor characterized by being coated with paint.

(2) A system for inputting information using an input device on an input screen of a computer having a touch sensor, wherein the input device has a spike head and a shaft, and the spike head is made of hair, which is an insulator. , the shaft is an insulator,
A conductive paint is applied to the outside of the shaft, and the input device inputs information on the input screen by impregnating the head of the ear with a conductive liquid. system.

(3) The input system according to (2), wherein the conductive liquid has a volume resistivity of 10 ⁶ Ωcm or less.

(4) The input system according to (2), wherein the conductive liquid is tap water.

FIG. 2 is a perspective view showing a state in which input is being performed using a stylus pen on a tablet having a touch sensor. FIG. 1 is a perspective view of a liquid crystal display device having a touch sensor. 3 is a sectional view taken along line AA in FIG. 2. FIG. FIG. 3 is a circuit diagram showing the operation of a touch sensor. 5 is a timing chart showing the operation of FIG. 4. FIG. FIG. 3 is a cross-sectional view showing the principle of detecting capacitance changes. 7 is a timing chart showing a state in which a change in capacitance is detected. This is an external view of a traditional brush. It is a figure explaining the detail of the hair which constitutes a head of a panicle. FIG. 9 is an external view of the brush shown in FIG. 8 with the ear neck loosened. FIG. 11 is a perspective view showing a state in which the brush of FIG. 10 is used as an input device of a touch sensor. 12 is an equivalent circuit showing the operation of FIG. 11. FIG. 1 is an external view of an input device (brush) according to the present invention. 14 is a sectional view taken along line BB in FIG. 13. FIG. 14 is a sectional view taken along the line CC in FIG. 13. FIG. It is an external view of the input device (brush) of the present invention in a state where the tip of the ear is soaked with water. 17 is an equivalent circuit showing the operation when the input device (pen) of FIG. 16 is used. It is an external view showing the input device (brush) of the present invention in a state where the base of the ear does not contain water. FIG. 2 is an external view of the input device (brush) according to the present invention, showing a case where conductive paint is applied to half of the shaft. FIG. 2 is an external view showing an input device (brush) of Example 2. FIG. 21 is a sectional view taken along line DD in FIG. 20. FIG. 21 is a sectional view taken along line EE in FIG. 20. FIG. 21 is an equivalent circuit showing the operation when the input device (pen) of FIG. 20 is used. It is a sectional view showing the tip and shaft of the brush. FIG. 7 is a cross-sectional view showing the head and shaft of the input device in Example 3. FIG. 7 is a cross-sectional view showing the head and shaft of the input device in another aspect of the third embodiment.

The contents of the present invention will be explained in detail below using Examples. In the following explanation, a liquid crystal display device is described as an example of a display device incorporating a touch panel function, but the present invention is similarly applicable to other display devices such as an organic EL display device and a micro LED display. be able to. The same applies when using a touch panel independent of the display device. Note that in this specification, the term "touch panel" does not necessarily refer to a touch panel independent of a display device, but may also refer to a touch sensor incorporated in a display device.

FIG. 1 is a perspective view showing a state in which input is being performed using a stylus pen 20 on a tablet 1 using a liquid crystal display device with a built-in touch sensor. In the tablet 1, the periphery of the display area 10 is surrounded by a casing 410 made of metal or resin. The display area of the tablet 1 also serves as an input surface 10 (hereinafter simply referred to as input surface 10) of a touch sensor.

In FIG. 1, input is performed on the input surface 10 using a stylus pen 20. Conventionally, the stylus pen 20 has often been composed of a hard conductive pen made of metal or the like. On the other hand, in order to prevent the input surface 10 of the tablet 1 from being damaged, a stylus pen with a soft touch surface has also been developed. For example, a method has been developed in which a cotton-like resin is impregnated with a conductive paint containing conductive fine particles and then shaped using a binder.

Furthermore, a stylus pen with a brush-like or brush-like tip that allows input of calligraphy fonts has been developed, and various applications have been developed to enable this system. However, in such conventional stylus pens, the tip of the pen is formed of conductive bristles, and the shaft is also different from that of a traditional brush.

On the other hand, there are many people who want to improve their calligraphy, and there are many calligraphy schools all over the country. However, it has become difficult to use the method used in the past, where many people were gathered in one room and a calligrapher taught them. Therefore, there is a demand for being able to teach calligraphy via correspondence using tablets.

In addition, practicing calligraphy required a large amount of paper, and discarding the paper after use was also a problem. Furthermore, there was also a desire to prevent stains caused by ink. If you can practice calligraphy using a tablet, you can solve problems like this.

A stylus pen having a tip resembling a brush has been developed, and applications have also been developed that use the stylus to create a typeface that looks like it was written with a brush. However, such stylus pens use conductive bristles at the tip, and the shaft of the stylus pen is also different from that of conventional brushes.

On the other hand, in calligraphy, exemplary ``good calligraphy'' can often only be achieved using traditional calligraphy brushes. In order to write ``good handwriting,'' calligraphers hone their skills, and this skill also includes the ability to choose good brushes. That is, with an input method that uses conductive bristles and a stylus pen with a corresponding shaft, it is difficult to achieve the purpose of practicing calligraphy using a traditional "brush."

In addition, the ``calligraphy'' of an excellent calligrapher can be registered as digital art, but in many cases, such calligraphy is only possible using a traditional ``brush''. An object of the present invention is to realize an input device that can take advantage of the characteristics of a traditional brush when writing calligraphy on the input screen of a tablet.

FIG. 2 is a perspective view of a liquid crystal display device 2 having a touch panel function and housed in the tablet 1 of FIG. 1. In FIG. 2, a counter substrate 200 having a black matrix and the like is disposed on a TFT substrate 100 on which pixel electrodes and the like are formed in a matrix. A liquid crystal is sandwiched between a TFT substrate 100 and a counter substrate 200. A display area of a liquid crystal display device is formed in a portion where the TFT substrate 100 and the counter substrate 200 overlap. A touch panel input surface 10 of an in-cell touch panel (a touch panel built into a liquid crystal display device) is formed overlapping this display area.

On the input surface 10, when viewed from above, the drive electrodes Rx extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). Further, the detection electrodes Tx extend in the vertical direction and are arranged in the horizontal direction. As shown in FIG. 3 and the like, the drive electrode Rx is formed on the outer surface of the counter substrate 200, and the detection electrode Tx is formed on the inner surface of the TFT substrate 100. A capacitance is formed at the intersection of the drive electrode Rx and the detection electrode Tx, and the touch signal detects a change in this capacitance.

In FIG. 2, the portion where the TFT substrate 100 does not overlap with the counter substrate 200 is a terminal region 150, in which a driver IC 160 is arranged, and a flexible wiring board 170 for supplying signals and power to the liquid crystal display device. is connected. A touch panel flexible wiring board 180 is connected to the outer end of the counter substrate 200 in order to supply a drive signal to the drive electrode Rx.

Although not shown in FIG. 2, a backlight is arranged on the back surface of the TFT substrate 100. In FIG. 2, a flexible wiring board 180 for a touch panel is connected to a flexible wiring board 170, and the flexible wiring board 170 is folded back to the back of the backlight to make the external shape of the tablet compact.

FIG. 3 is a sectional view taken along line AA in FIG. In FIG. 3, a detection electrode Tx extends in the lateral direction (y direction) on the inner surface of the TFT substrate 100. Actually, the common electrode formed on the TFT substrate 100 also serves as this. A counter substrate 200 is disposed with the liquid crystal layer 300 in between, and drive electrodes Rx extend in a direction perpendicular to the plane of the paper (x direction) and are arranged in the lateral direction (y direction) on the outside of the counter substrate 200. A touch panel capacitor Ct is formed at the intersection of the TFT substrate 100 and the counter substrate 200. Note that in an actual product, the thickness of the liquid crystal layer is several μm, whereas the thickness of the TFT substrate 100 and the counter substrate 200 is about 0.5 mm. In FIG. 3, the thickness of the liquid crystal layer 300 is exaggerated.

FIG. 4 is a plan view showing the arrangement of the drive electrode Rx and the detection electrode Tx. In FIG. 4, the drive electrodes Rx extend in the vertical direction (x direction in coordinates) and are arranged in the horizontal direction (vertical direction in coordinates). Further, the detection electrodes Tx extend in the horizontal direction and are arranged in the vertical direction. A capacitor Ct is formed at the intersection of the drive electrode Rx and the detection electrode Tx.

In FIG. 4, drive voltages such as VR1, VR2, and VR3 are applied to the drive electrodes Rx in order from the left. Then, voltages corresponding to VR1, VR2, VR3, etc. are output to the selected detection electrode Tx. This voltage has a value corresponding to the capacitance Ct at each intersection. In FIG. 4, VT1 means a detection signal appearing on the electrode Tx1, and is a general term for voltages generated in order corresponding to VR1, VR2, VR3, etc., such as VT11, VT12, VT13, etc. The same applies to VT2 and below. The detection voltage is sequentially detected from the detection electrodes Tx1, Tx2, etc. as indicated by the right arrow in FIG.

FIG. 5 shows the contents explained above in a time chart. In FIG. 5, the horizontal direction is the time axis. In FIG. 5, Tx1, Tx2, etc. shown on the upper side indicate a state in which a signal voltage is taken in at each detection electrode in an ON state.

In FIG. 5, if the detection electrode Tx1 is selected, drive voltages are sequentially applied to the drive electrodes Rx1, Rx2, . . . as VR1, VR2, . . . corresponding to this detection electrode. Then, detection voltages such as detection signals VT11, VT12, etc. are detected at the detection electrode Tx1 in correspondence with the drive voltage. Here, VT11, VT12, etc. mean signals sequentially detected by the detection electrode Tx1. Similarly, VT21, VT22, etc. mean signals sequentially detected by the detection electrode Tx2.

FIG. 6 is a cross section showing a state in which a stylus pen or a human finger contacts the intersection of the detection electrode Tx1 and the drive electrode Rx2, and a capacitance CA is added in parallel between the drive electrode Rx and the reference potential. It is a diagram. As a result, the detection voltage detected at the detection electrode Tx1 changes.

FIG. 7 is a time chart showing this state. The difference between FIG. 7 and FIG. 5 is the detection voltage VT12 when the second driver voltage VR2 is applied to the detection electrode Tx1. In FIG. 7, the VT12 indicated by the white arrow is smaller than the corresponding VT12 in FIG. In other words, this indicates that the detected voltage has decreased in the corresponding portion due to the addition of the capacitor CA in parallel. By detecting this decreased detection voltage VT12, etc., the touch position of a finger or stylus pen on the touch panel can be detected.

The operating principle of the touch panel explained above is the same when the input device is a brush. FIG. 8 is an external view of a traditional brush 50. The traditional brush 50 is roughly divided into a tip 60 and a shaft 70. The hair constituting the ear neck 60 is animal hair. Various animal hairs are used depending on the purpose of the brush 50 or where the brush 50 is produced. This hair is then processed by the skill of the brush craftsman to make it suitable for brushes. Even for a single brush, as shown in Figure 9, the bristles are processed into multiple lengths and then put together to form a single brush. Reference numeral 600 in FIG. 9 is a cross-sectional view of one side of the ear neck 60. This shows that it is made up of hairs of multiple lengths. In FIG. 9, for example, 600 is called "life hair," 602 is called "throat," 603 and 604 are called "belly," and 605 and 606 are called "waist." These hairs of different lengths are arranged and combined into one brush.

Bamboo is the most commonly used material for the shaft of the brush 70, followed by wood, with very few other materials being used. The material for the head 60 and the material for the shaft 70 are traditionally selected by calligraphers based on the most suitable weight, contact, etc. of the brush when writing calligraphy. This is because it is possible.

When the brush is completed, the hair at the tip (neck) is hardened with funori. Therefore, it is necessary to remove this funori before use. FIG. 10 is an external view showing a state in which Funori has been removed with water or the like and dried again. Since the bristles of the head of the brush 60 are made of an insulating material, the head of the brush as a whole is also an insulator, and the shaft 70 of the brush is also an insulator. Here, an insulator is defined as having a volume resistivity of 10 ⁹ Ωcm or more.

FIG. 11 is a perspective view showing a state in which the brush 50 shown in FIG. 10 is used as an input device to the input surface 10 of the tablet 1 having a touch sensor. FIG. 11 shows a character being written on the input surface 10 of the tablet 1 with a brush 50. However, the configuration shown in FIG. 11 does not operate as an input device for the tablet 1 having a touch sensor. That is, although humans are conductors, both the tip 60 and the shaft 70 of the brush 50 are insulators, so the capacitance between the brush 50 and the drive electrode formed on the touch panel is very small. Therefore, the change in capacitance between the drive electrode Rx and the detection electrode Tx is small. This is because, therefore, a voltage change that is large enough to be recognized as a detection signal is not generated.

FIG. 12 is an equivalent circuit showing this situation. In FIG. 12, a capacitor Ct is formed between the drive electrode Rx and the detection electrode Tx. In FIG. 12, a capacitor CA1 and a capacitor CH are connected between the drive electrode Rx and the reference potential. CH is the capacitance between the human and the reference potential. CA1 is the capacitance between the human being and the drive electrode, and is the pen part in FIG.

In FIG. 12, since both the tip 60 and the shaft 70 of the brush 50 are insulators, the capacitance through them is very small. The series capacitance of capacitor CA1 and capacitor CH is determined by the smaller capacitance. In other words, when the capacitance of the capacitor CA1 is C1 and the capacitance of the capacitor CH is C2, the series capacitance C12 is C1×C2/(C1+C2). When the voltage applied to the drive electrode Rx is VR, the voltage detected by the detection electrode is VR×Ct/(Ct+C12). When C12 is very small compared to Ct, almost no change in potential occurs when the brush 50 touches the tablet input surface 10. In other words, the touch position cannot be detected.

In order to solve this problem, we have developed a method in which the head of the spike is made of conductive hair, which reduces the impedance between the human body and the drive electrode Rx, thereby increasing the change in capacitance when touched with a brush. being developed. However, this method has the problems mentioned above. The present invention realizes an input device that allows input to the input surface of a touch panel while maintaining the traditional characteristics of a brush.

FIG. 13 is an external view of a brush 50 as an input device for a touch panel according to the present invention. FIG. 13 has almost the same configuration as the traditional brush shown in FIG. The difference between FIG. 13 and FIG. 9 is that a conductive paint 80 is applied to the outer surface of the shaft 70 to make the outer surface conductive. 14 is a sectional view taken along line BB in FIG. 13, and FIG. 15 is a sectional view taken along line CC in FIG. In FIGS. 14 and 15, the base material of the shaft 70 is bamboo, and the inside is hollow. A conductive paint 80 is applied to the outside of the shaft 70, which has a circular cross section, to a predetermined thickness.

The reason why the outside of the shaft 70 of the brush 50 is made conductive is to improve the coupling between the capacitance formed by the human body and the drive electrode Rx on the touch panel. In the brush 50, the tip 60 and the shaft 70 are manufactured separately. The ear head 60 is completed through many steps. On the other hand, the shaft 70 determines the weight, feel, etc. of the entire brush, and is still important. A recess is formed at the end of the shaft 70, and the tip of the brush is adhered to the recess using an adhesive to complete the brush.

The brush 50 shown in FIG. 13 is manufactured in the same process as a conventional brush. The conductive paint 80 shown in FIGS. 13 to 15 is applied in the final step of manufacturing the shaft. The conductive paint 80 is made of, for example, a resin such as epoxy, acrylic, or urethane in which fine particles of carbon, nickel, copper, or the like are dispersed as a conductive material. That is, conductive fine particles are kneaded in a vehicle for forming such a coating film, and the mixture is applied to the outside of the shaft 70.

After application, the coating film 80 is sintered (dried) and hardened. By the way, since the shaft 70 is made of bamboo, it needs to be made of a material that can be sintered at low temperatures. If it is a two-component reaction type such as epoxy or urethane, it can be dried and cured in a short time at about 60°C. Furthermore, even a one-component acrylic resin lacquer type can be dried and cured at low temperatures.

As the conductive filler, fine particles of carbon, nickel, aluminum, copper, etc. can be used. Carbon is the cheapest and has stable conductivity, but the color of the coating film is limited to almost black. In other words, if the color of the shaft is black, carbon fine particles are most suitable.

On the other hand, when fine particles of nickel, aluminum, copper, etc. are used as the filler, it is possible to form a nearly transparent coating film. Therefore, a coating film of a desired color can be formed by dispersing an appropriate pigment in the coating material. Note that nickel is most suitable as the fine particles made of the above-mentioned metal material because it is difficult to oxidize.

For the purpose of the present invention, it is sufficient that the volume resistivity of the conductive coating film 80 is 10 ³ Ωcm or less, and more preferably 100 Ωcm or less. Further, the thickness of the coating film 80 may be selected to be a thickness that is easy to apply. However, it is preferable that the coating film 80 has a thickness that does not impair the feel of a traditional brush. Taking these into consideration, the appropriate thickness of the conductive coating film 80 is 10 μm to 100 μm.

However, even if the brush shown in FIG. 13 is used as an input means to the touch panel, a sufficient detection signal cannot be obtained. This is because the ear head 60 is made of animal hair and is an insulator. That is, although the coupling between a person and the brush 50 can be improved by the conductive film 80 formed on the shaft 70 of the brush, the capacitive coupling formed by the driver electrode Rx of the touch panel and the person can be improved by using the tip 60, which is an insulator. damaged by the presence of

In contrast, in the present invention, as shown in FIG. 16, the tip 60 of the brush 50 is impregnated with water to impart conductivity to the tip 60, and the brush in this state can be used as a touch panel input device. used as In FIG. 16, the ear head 60 is in a water-impregnated state, and this state is shown by hatching in the ear head 60.

By the way, the brush 50 shown in FIG. 13 is a new brush, and the tip 60 has been shaped with cloth seaweed. To actually use the brush 50, it is necessary to remove the cloth seaweed with water or the like and loosen the brush 60. In the brush 50 shown in FIG. 16, the shape of the ear head 60 is adjusted by soaking water in the ear head 60 from which the cloth seaweed has already been removed. That is, by impregnating the ear head 60 (62) with water, the shape of the ear head 60 (62) can be adjusted in the same way as when soaking ink.

In this way, by impregnating the brush with water, it is possible to impart conductivity to the tip 60, and it is also possible to shape the brush into the same shape as when actually writing "calligraphy" using ink. The water used may be ordinary tap water such as drinking water used in daily life. The volume resistivity of normal tap water is, for example, 5×10 ³ Ωcm. For the purpose of improving the coupling between human capacitance and the drive electrode Rx of the touch panel, a volume resistivity of 10 ⁶ Ωcm or less is sufficient. In addition, considering that ions of substances contained in the ear head 60 are also added to the water impregnated into the ear head 60, the volume resistivity of the water impregnated into the ear head 60 will further decrease. .

When input was made to the touch panel using a brush having such a configuration as shown in FIG. 16, a sufficient detection signal could be obtained. When they applied a calligraphy input application to write calligraphy on the input surface of the touch panel, they were able to write calligraphy similar to that written using a traditional brush.

It is also possible to use liquids other than tap water. For example, methanol, ethanol, etc. can be used for this purpose since they have a volume resistivity that is approximately the same as tap water. The volume resistivity of pure water is higher than tap water, about 5×10 ⁵ Ωcm. However, even when the present invention was tested using pure water, a sufficient detection signal could be detected. Therefore, the object of the present invention can be achieved if the volume resistivity of the liquid is 10 ⁶ Ωcm or less, preferably 10 ⁵ Ωcm or less. Other liquids can be used as long as they do not deteriorate the brush or the input surface 10 of the touch panel.

FIG. 17 shows an equivalent circuit when writing characters on the input surface of a touch panel using a "brush" as shown in FIG. 16. In FIG. 17, the coupling capacitance CA2 existing between the capacitance of the human body and the drive electrode Rx formed on the input surface of the touch panel is larger than CA1 in FIG. As a result, the series capacitance between CA2 and CH has a size close to that of the capacitance Ct formed between the drive electrode Rx and the detection electrode Tx.

In FIG. 17, when the capacitance of the capacitor CA2 is C3 and the capacitance of the capacitor CH is C2, the series capacitance C23 is C3×C2/(C3+C2). When the voltage applied to the drive electrode Rx is VR, the voltage detected by the detection electrode is VR×Ct/(Ct+C23). When C23 becomes comparable to Ct, a change in potential when the brush 50 touches the tablet input surface 10 becomes large enough to be detected by the detection electrode Tx.

FIG. 18 is an external view of the brush 50 when the cloth seaweed on the head 60 of the brush 50 is left at the base 63 of the head 60 without being removed. The elasticity of the brush when writing with a brush differs depending on whether or not the cloth seaweed at the base 63 of the head 60 is removed. Therefore, either one may be selected depending on the preference of the user of the brush, or even the same user may use a brush with a different loosening range of the tip 60 depending on the typeface.

When characters were written on the input surface 10 of the touch panel using a brush 50 as shown in FIG. 18, there was no significant difference in writing compared to when a brush 50 as shown in FIG. 16 was used. was completed. This is because the unraveled portion of the root 63 of the ear neck 60 has a small width and does not have a large effect on the coupling capacity.

FIG. 19 is an external view of a brush 50 showing another aspect of the first embodiment. For some reason, it may not be possible to form the conductive paint 80 on the entire shaft 70. Still, for the purpose of the present invention, it is desirable to apply the conductive paint 80 to 1/2 or more of the length of the shaft 70, as shown in FIG. In this case, the conductive paint 80 is preferably applied to a portion close to the ear neck 60, as shown in FIG. 19. This is because it is advantageous for coupling with the ear head 60 by capacitance.

FIG. 20 is an external view of a brush 50 according to the second embodiment. Also in FIG. 20, a conductive paint 80 is formed on the outside of the shaft 70. The difference between FIG. 20 and FIG. 13 of the first embodiment is that the inner core portion of the brush shaft 70 is filled with a conductive material 75. As a result, a large capacitance is also formed between the outside of the shaft 70 and the inside of the shaft, making it possible to provide an input device with better sensitivity to the touch panel.

21 is a sectional view taken along line DD in FIG. 20, and FIG. 22 is a sectional view taken along line EE in FIG. 21 and 22, the shaft 70 is made of bamboo, and a conductive paint 80 is formed around the shaft 70, as in the first embodiment. In FIGS. 21 and 22, the hollow part of the bamboo is filled with a conductive substance 75 (hereinafter referred to as conductive filler 75). As a result, a capacitance CB is formed between the conductive filler 75 and the conductive paint 80 on the outside of the shaft 70. Since this capacitance CB is added as a coupling capacitance between the tip 60 of the brush and the human body, input sensitivity can be further increased.

The volume resistivity of the conductive filler 75 in Example 2 can be selected from a wide range for the purpose of the present invention. For example, like the conductive paint 80 on the outside of the shaft 70, it is sufficient if it is 10 ³ Ωcm or less, and even better if it is 100 Ωcm or less. As the material for the conductive filler 75, a material that is inexpensive and easy to fill may be used. Furthermore, it is better for the filler to have a small weight so as not to have a large effect on the weight of the brush 50. This is because the weight of the brush also affects the feeling of using a traditional "brush."

As such a conductive filler 75, a conductive paint made of resin and carbon as a conductive filler may be poured into the cavity. At this time, if a two-component reactive epoxy resin or the like is used as a binder, it can be cured at a low temperature. By using the same material as the outer conductive paint 80, the manufacturing process can be simplified.

Alternatively, a structure may be adopted in which a material containing conductive fine particles in epoxy resin is sintered into a conductive core, and this is inserted into the hollow part of the shaft. Alternatively, a resin such as polyurethane or acrylic in which carbon as conductive particles is dispersed may be sintered, shaped into a conductive core, and inserted into the hollow part of the shaft. Alternatively, a synthetic fiber may be used as the base material, impregnated with a resin containing conductive fine particles, shaped into a conductive core, and inserted into the hollow portion of the shaft 70. If weight considerations and cost permit, a metal core may be inserted into the hollow portion of the shaft 70.

In FIGS. 20 to 22, the shaft 70 has been described as being made of bamboo. In traditional brushes, the second most commonly used material for the shaft 70 after bamboo is wood. When the shaft 70 is made of wood, a hole is formed in the shaft 70 along the axis using a drill, and a conductive filler is inserted into this hole in the same manner as in the case of bamboo.

By the way, pencils use a graphite lead in their wooden shafts. Graphite core is made by kneading and sintering graphite particles and clay. Therefore, pencil lead is a good conductor. For the purpose of Example 2, it is possible to use a shaft made by the same method as a pencil and coated with conductive paint on the outside. A pencil is suitable as the shaft 70 of the brush 50 for Example 2 because the technology for manufacturing it at low cost has been established.

FIG. 23 is an equivalent circuit when writing characters on the input surface of a touch panel using a "brush" as shown in FIG. 20. In FIG. 23, the coupling capacitance CA3 existing between the capacitance CH of the human body and the drive electrode Rx formed on the input surface of the touch panel is larger than CA2 in FIG. 17. As a result, the series capacitance between CA3 and CH also increases.

In FIG. 23, when the capacitance of the capacitor CA3 is C4 and the capacitance of the capacitor CH is C2, the series capacitance C33 is C4×C2/(C4+C2). When the voltage applied to the drive electrode is VR, the voltage detected by the detection electrode is VR×Ct/(Ct+C33). As C33 becomes larger, the change in voltage, that is, the detected voltage becomes larger. Therefore, more accurate touch sensor operation is possible.

In the manufacturing process of the brush 50, the tip 60 and the shaft 70 are manufactured separately. As shown in FIG. 24, a recess 77 into which the ear head 60 is inserted is formed in the shaft 70. After the ear head 60 is completed, an adhesive 65 is applied to the base of the ear head 60, and then the ear head 60 is inserted into the recess 77 of the shaft 70, and is bonded and fixed.

In Example 3, as shown in FIG. 25, a conductive adhesive 66 is used to bond the ear neck 60 and the shaft 70. The conductive adhesive 66 is, for example, a resin such as epoxy or acrylic resin in which conductive fine particles are dispersed. Graphite is most suitable as the conductive fine particles in terms of cost. In addition, fine particles of nickel, aluminum, copper, etc. can be used. As with the conductive filler material 75, the volume resistivity of the conductive adhesive 66 is sufficient if it is 10 ³ Ωcm or less, and even better if it is 100 Ωcm or less.

By using the conductive adhesive 66, it is possible to further improve the coupling between the conductive film 80 formed around the shaft 70 and the ear head 60 when it contains water. Therefore, it is possible to increase the detection signal when the brush 50 contacts the input surface of the touch panel. Note that the ear neck 60 and the shaft 70 may be bonded together with a non-conductive adhesive. Even in this case, if the ear head 60 containing water and the conductive shaft 70 come into contact, conduction will occur and a detection signal can be detected without any problem.

FIG. 26 is a sectional view showing another aspect of the third embodiment in which the shaft 70 is filled with a conductive filler 75. In FIG. 26, applying the conductive adhesive 66 to the base of the ear neck 60 is the same as in FIG. In FIG. 26, the core of the shaft 70 is filled with a conductive substance 75, which contacts the conductive adhesive 66 applied to the ear neck 60 and is electrically conductive.
In the configuration of FIG. 26, when the ear head 60 contains water, conduction occurs between the ear head 60 and the conductive filling 75, which is the core of the shaft 70, so that the human body and the input surface of the touch panel are connected. The capacitance is further increased, and the detection signal when the ear head 60 is touched on the touch panel input screen 10 can be further increased.

As described above, according to the present invention, it is possible to write "calligraphy" on the input surface of a touch panel with a brush while maintaining the characteristics of a traditional brush. Therefore, by using a tablet having a touch panel function, it is possible to practice calligraphy and faithfully input calligraphy on the input surface of the touch panel. Furthermore, it will also be possible to write calligraphy as a form of digital art from a tablet screen.

DESCRIPTION OF SYMBOLS 1...Tablet with touch panel function, 2...Liquid crystal display device with touch panel function, 10...Touch panel input surface, 20...Stylus pen, 50...Brush, 60...Ear head, 61...Flipped ear head, 62...Water Contained ear neck, 63... Root of unraveled ear neck, 65... Adhesive, 60... Conductive adhesive, 70... Shaft, 71... Hollow part, 75... Conductive filling material, 80... Conductive paint, DESCRIPTION OF SYMBOLS 100... TFT board, 150... Terminal area, 160... Driver IC, 170... Flexible wiring board, 180 Flexible wiring board for touch sensor, 200... Counter substrate, 250... Protective film, 300... Liquid crystal layer, 410... Housing, 600 ...One side cross-sectional view of the tip of the brush, 601... Life hair of the brush, 602... Life hair of the brush, 601... Life hair of the brush, 601... Life hair (of the brush), 602... Throat (of the brush), 603... Belt (of the brush), 604... Belt (of the brush), 605... Waist (of the brush), 606... Waist (of the brush), Rx... Drive electrode, Tx... Detection electrode, CA1... Capacitance, CA2... Capacitance, CA3... Capacitance, CB...capacitance between conductive paint and conductive filling material in axis, CH...capacitance of human being, Ct...capacitance between Rx and Tx electrodes

Claims (14)

An input device for a touch sensor having an axis connected to the ear head,
The head of the ear is composed of hair that is an insulator,
the shaft is an insulator;
An input device for a touch sensor, characterized in that a conductive paint is applied to the outside of the shaft. 2. The input device for a touch sensor according to claim 1, wherein the insulating hairs on the head of the ear are a collection of hairs of different lengths. The input device for a touch sensor according to claim 1, wherein the conductive paint has a volume resistivity of 10 ³ Ωcm or less. The input device for a touch sensor according to claim 1, wherein the conductive paint has a structure in which carbon particles are dispersed in a resin. The input device for a touch sensor according to claim 1, wherein the conductive paint has a structure in which metal particles are dispersed in a resin. The input device for a touch sensor according to claim 1, wherein the core of the shaft is filled with a conductive material. The input device for a touch sensor according to claim 6, wherein the conductive material has a volume resistivity of 10 ³ Ωcm or less. 7. The input device for a touch sensor according to claim 6, wherein the conductive material is a resin in which carbon is dispersed. 2. The input device for a touch sensor according to claim 1, wherein the ear head and the shaft are bonded together using a conductive adhesive. The core of the shaft is filled with a conductive substance,
2. The input device for a touch sensor according to claim 1, wherein the ear head and the shaft are bonded together using a conductive adhesive. The input device for a touch sensor according to claim 10, wherein the conductive substance and the conductive adhesive are electrically connected. A system for inputting information using an input device on an input screen of a computer having a touch sensor,
The input device has a head and a shaft,
The head of the ear is composed of hair that is an insulator,
the shaft is an insulator;
A conductive paint is applied to the outside of the shaft,
An input system characterized in that the input device inputs information on an input screen by impregnating the head of the ear with a conductive liquid. The input system according to claim 12, wherein the conductive liquid has a volume resistivity of 10 ⁶ Ωcm or less. 13. The input system of claim 12, wherein the conductive liquid is tap water.

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