Touchpad device

Abstract

A touchpad device includes a cover plate, a circuit board, a bonding layer, a plurality of force detection units, and a feedback component. The circuit board is disposed under the cover plate and has a first surface facing the cover plate and a second surface away from the cover plate. The bonding layer is disposed between the cover plate and the first surface and includes a bonding portion and at least one cutout portion. Force detection units are disposed on the second surface. Each force detection unit includes a plurality of adjacent strain electrodes and a plurality of temperature-compensating electrodes. The strain electrodes are arranged in the alignment direction of the cover plate and the bonding layer, corresponding to both the bonding portion and the cutout portion. The temperature-compensating electrodes are arranged in the alignment direction, corresponding to either the bonding portion or the cutout portion. The feedback component is disposed on the second surface and configured to provide tactile feedback.

Description

[Technical Field]

[0001] This disclosure relates to a touchpad device. [Previous Technology]

[0002] The current development trend of touchpad devices is from simple touch functionality to the integration of touch, force sensing, and haptic feedback. A conventional touchpad device places a force sensor on an elastic member (e.g., a metal bracket) and fixes the elastic member to a touch circuit board, for example, Chinese Patent Application Publication No. 107025017B. However, this conventional technology has disadvantages such as a large number of components, complex assembly process, high overall cost, and large overall thickness.

[0003] Therefore, how to propose a touchpad device that can solve the above problems is one of the problems that the industry is currently eager to invest research and development resources to solve. [Summary of the Invention]

[0004] In view of this, one of the objectives of this disclosure is to provide a touchpad device that can solve the above-mentioned problems.

[0005] To achieve the above objectives, according to one embodiment of this disclosure, a touchpad device includes a cover plate, a circuit board, a bonding layer, a plurality of force detection units, and a feedback component. The circuit board is disposed under the cover plate and has a first surface facing the cover plate and a second surface away from the cover plate. The bonding layer is disposed between the cover plate and the first surface and includes a bonding portion and at least one cutout portion. The force detection units are disposed on the second surface. Each force detection unit includes a plurality of adjacent strain electrodes and a plurality of temperature compensation electrodes. The strain electrodes are simultaneously disposed corresponding to the bonding portion and the cutout portion in the arrangement direction of the cover plate and the bonding layer. The temperature compensation electrodes are disposed corresponding to one of the bonding portion and the cutout portion in the arrangement direction. The feedback component is disposed on the second surface and configured to provide tactile feedback.

[0006] In one or more embodiments disclosed herein, the hollow portion is a closed slot.

[0007] In one or more embodiments disclosed herein, the number of hollow portions is multiple. The hollow portions correspond to force detection units in their respective arrangement directions.

[0008] In one or more embodiments disclosed herein, the number of cutout portions is multiple. Each cutout portion corresponds to a multiple of the force detection units in the arrangement direction.

[0009] In one or more embodiments disclosed herein, the touchpad device further includes a support member and a plurality of elastic members. The support member is disposed under the circuit board. The elastic members are disposed between the circuit board and the support member.

[0010] In one or more embodiments disclosed herein, the elastic element is provided in the arrangement direction corresponding to the hollow portion.

[0011] In one or more embodiments disclosed herein, the feedback component includes a coil layer and a magnet assembly.

[0012] In one or more embodiments disclosed herein, a coil layer is disposed on a circuit board. A magnet assembly is disposed on a support member.

[0013] In one or more embodiments disclosed herein, the feedback component is a linear motor.

[0014] In one or more embodiments disclosed herein, the strain electrode and the temperature compensation electrode of each force detection unit form a bridge circuit.

[0015] In summary, in the touchpad device disclosed herein, since the force detection unit includes both a strain electrode and a temperature compensation electrode, it has a built-in temperature compensation function, thereby solving the detection deviation problem caused by thermal effects. By arranging the strain electrode in the arrangement direction of the cover plate and the bonding layer simultaneously corresponding to the joint portion and the cutout portion of the bonding layer (i.e., spanning the joint portion and the cutout portion), the deformation of the strain electrode when the cover plate of the touchpad device is pressed can be increased, thereby significantly improving sensitivity. By arranging the temperature compensation electrode in the arrangement direction of the cover plate and the bonding layer corresponding to either the joint portion or the cutout portion (i.e., not spanning the joint portion and the cutout portion), strain can be avoided, thereby providing an accurate temperature change reference.

[0016] The above description is only used to illustrate the problem to be solved by this disclosure, the technical means to solve the problem, and the effects produced, etc. The specific details of this disclosure will be described in detail in the following implementation methods and related figures.

Implementation Method

[0018] Several embodiments of this disclosure will be disclosed below with reference to the drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this disclosure. That is, in some embodiments of this disclosure, these practical details are not necessary. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0019] Please refer to Figure 1, which is a schematic diagram illustrating an electronic device 100 according to an embodiment of the present disclosure. As shown in Figure 1, in this embodiment, the electronic device 100 includes a host 110, a display 120, and a touchpad device 200. The touchpad device 200 is disposed within the host 110 and is exposed by a recess 111a in the housing portion 111 of the host 110. The touchpad device 200 is an input device disposed in the host 110, but the present disclosure is not limited thereto. Furthermore, the touchpad device 200 is a rectangular area composed of length and width, and the left and right width W can be extended according to different models (as shown in the elongated shape in Figure 1), and the size is not limited to the length shown in Figure 1. In practical applications, the touchpad device 200 can also be an electronic product that uses a touchpad as an input or operation interface (e.g., a personal digital assistant, a keyboard including a touchpad, etc.). In other words, the concept of the touchpad device 200 disclosed herein can be applied to any electronic product that uses a touchpad as an input or operation interface. The structure, function, and connection and operation relationship between some of the components included in the touchpad device 200 will be described in detail below.

[0020] Please refer to Figure 2, which is a cross-sectional schematic diagram of the touchpad device 200 shown in Figure 1. As shown in Figure 2, in this embodiment, the touchpad device 200 includes a first component 210, a second component 220, and a plurality of elastic members 230. The first component 210 includes a cover plate 211, a bonding layer 212, and a circuit board 213. The cover plate 211 has a bonding area 211a and a non-bonding area 211b. The bonding layer 212 is disposed under the cover plate 211 and has a bonding portion 212a corresponding to the bonding area 211a and a plurality of cutout portions 212b corresponding to the non-bonding area 211b. The circuit board 213 is disposed under the bonding layer 212 and includes a touch sensing element 213a (see Figure 7) and a coil layer 213b. The second component 220 includes a support member 221 and a magnet assembly 222 disposed on the support member 221. The support member 221 is fixed to the bottom surface of the groove 111a of the housing portion 111 (e.g., through a screw), wherein the groove 111a of the housing portion 111 is located on the outer surface of the housing portion 111. An elastic member 230 is disposed between the first component 210 and the second component 220. The magnet assembly 222 disposed on the support member 221 and the coil layer 213b disposed on the circuit board 213 constitute a vibration module. The elastic member 230 is configured to reduce vibration noise and effectively release vertical vibration stress.

[0021] For example, the joint area 211a of the cover plate 211 can be defined by the area where the bottom surface of the cover plate 211 is joined to the joint portion 212a of the joint layer 212, while the non-joint area 211b of the cover plate 211 can be defined by the area where the bottom surface of the cover plate 211 is not joined to the joint portion 212a of the joint layer 212 (i.e., the corresponding cutout portion 212b), but this disclosure is not limited thereto.

[0022] Please refer to Figure 3, which is a top view showing some components of the touchpad device 200 in Figure 2. As shown in Figures 2 and 3, in this embodiment, the cutout portion 212b is a closed slot, but this disclosure is not limited thereto. The elastic member 230 corresponds to the cutout portion 212b in the arrangement direction D of the cover plate 211 and the bonding layer 212. It should be noted that by providing the cutout portion 212b on the bonding layer 212 provided between the cover plate 211 and the circuit board 213, and making the elastic member 230, which serves as a fulcrum, correspond to the cutout portion 212b in the arrangement direction D of the cover plate 211 and the bonding layer 212, the touchpad device 200 can have better deformation for vertical vibration, thereby achieving the effect of enhancing vertical vibration.

[0023] In some embodiments, the material of the bonding layer 212 includes pressure-sensitive adhesive (PSA), but this disclosure is not limited thereto.

[0024] In some embodiments, as shown in Figure 2, the bonding layer 212 has a thickness T of about 50 µm to about 500 µm. If the thickness T of the bonding layer 212 is less than 50 µm, sufficient compression cannot be provided when the user presses the cover plate 211. If the thickness T of the bonding layer 212 is greater than 500 µm, it will affect the generation of the detection capacitance signal of the touch sensing element 213a (see Figure 7).

[0025] In some embodiments, the Young's modulus of the elastic element 230 is in the range of 0.55 MPa to 0.8 MPa. The elastic element 230 having a Young's modulus in the aforementioned range can effectively reduce vibration noise and effectively release vibration stress in the vertical direction.

[0026] In some embodiments, the material of the elastic element 230 may be silicone, but this disclosure is not limited thereto.

[0027] In some embodiments, the support member 221 is a silicon steel sheet. The silicon steel sheet has a magnetic conductivity, which will constrain the dispersion of the magnetic field, making the magnetic field more concentrated, thereby making the magnetic field lines more concentrated in the same range.

[0028] As shown in Figure 3, in this embodiment, one of the cutout portions 212b (e.g., the upper cutout portion 212b) is adjacent to the edge of the bonding layer 212 (e.g., the upper edge of the bonding layer 212) and is separated by a distance S1, and the distance S1 is greater than approximately 2 mm. By limiting the distance S1 from the cutout portion 212b to the adjacent edge of the bonding layer 212 as described above, the problem of the bonding layer 212 failing to adhere to the cover plate 211 can be avoided. In addition, the upper cutout portion 212b in Figure 3 may also be separated from the right edge or left edge of the bonding layer 212 by the aforementioned distance S1. The lower cutout portion 212b in Figure 3 may also be separated from the lower edge, left edge, or right edge of the bonding layer 212 by the aforementioned distance S1.

[0029] As shown in Figure 3, in this embodiment, one of the cutout portions 212b (for example, the upper cutout portion 212b) has a width W. The width W is greater than approximately 10 mm. By limiting the width W of the cutout portion 212b to the aforementioned range, the problem of insufficient deformation of the bonding layer 212 during vibration can be avoided. Specifically, the cutout portion 212b is elongated, and the aforementioned width W is the smaller lateral dimension of the cutout portion 212b. In contrast, the larger lateral dimension of the cutout portion 212b is its length. The lower cutout portion 212b in Figure 3 may also have the aforementioned width W.

[0030] Please refer to Figures 4, 5, and 6. Figure 4 is a schematic diagram showing the touch electrode layer of the touch sensing element 213a in Figure 2. Figure 5 is a partially enlarged view showing the first touch electrode layer 213a1 in Figure 4. Figure 6 is another partially enlarged view showing the first touch electrode layer 213a1 in Figure 4. As shown in Figures 4 to 6, in this embodiment, the touch sensing element 213a includes a first touch electrode layer 213a1. The first touch electrode layer 213a1 has a first sensing area A1 and a second sensing area A2. The first sensing area A1 and the second sensing area A2 correspond to the bonding area 211a and the non-bonding area 211b respectively in the arrangement direction D (refer to Figure 2) (that is, the second sensing area A2 corresponds to the cutout portion 212b). The line width of the second sensing area A2 is greater than the line width of the first sensing area A1.

[0031] It should be noted that, according to Gauss's law, capacitance is proportional to the permittivity of the dielectric. Therefore, when a user touches the cover plate 211, the touch sensing element 213a will detect a difference in capacitance signals between the bonding area 211a and the non-bonding area 211b (because the permittivity of the bonding layer 212 is greater than that of the cutout portion 212b). This difference will result in the touch sensing element 213a detecting a significantly greater capacitance signal when the user touches the cover plate 211 above the bonding area 211a than when the user touches the cover plate 211 above the non-bonding area 211b. In this embodiment, by making the linewidth of the second sensing area A2 corresponding to the cutout portion 212b greater than the linewidth of the first sensing area A1, the difference in the detected capacitance signals between the bonding area 211a and the non-bonding area 211b can be compensated by increasing the area. In other words, the touch sensing element 213a in this embodiment compensates for the difference in detected capacitance signals by using an electrode structure.

[0032] In some embodiments, the touch sensing element 213a further includes a second touch electrode layer 213a2 (see Figure 8), and the second touch electrode layer 213a2 may also have the same or similar regions as the first sensing area A1 and the second sensing area A2 of the first touch electrode layer 213a1.

[0033] Please refer to Figure 7, which is a functional block diagram illustrating a touch sensing element 213a according to an embodiment of the present disclosure. As shown in Figure 7, in this embodiment, the touch sensing element 213a further includes a processing unit 213a3. The processing unit 213a3 is electrically connected to the first touch electrode layer 213a1 and the second touch electrode layer 213a2, and is configured to detect user touch on the cover plate 211 via the first touch electrode layer 213a1 and the second touch electrode layer 213a2, and generate a corresponding detection capacitance signal. In particular, the processing unit 213a3 is also configured to compensate for the difference in detection capacitance signals between the first sensing area A1 and the second sensing area A2. In other words, the touch sensing element 213a of this embodiment compensates for the difference in detection capacitance signals using software.

[0034] Please refer to Figure 8, which is a cross-sectional schematic diagram of the circuit board 213 in Figure 2. As shown in Figure 8, in this embodiment, the circuit board 213 further includes a shielding layer 213c. The first touch electrode layer 213a1, the second touch electrode layer 213a2, the shielding layer 213c, and the coil layer 213b are stacked sequentially from top to bottom and electrically isolated by an insulating layer 213d. The circuit board 213 further includes two solder resist layers 213e. The two solder resist layers 213e are respectively disposed on the upper and lower sides of the circuit board 213, and respectively cover and contact the first touch electrode layer 213a1 and the coil layer 213b.

[0035] As shown in Figure 8, in this embodiment, the coil layer 213b is made of copper. The circuit board 213 further includes a nickel layer 213f. The nickel layer 213f covers the coil layer 213b. By covering the coil layer 213b with the nickel layer 213f, the magnetic lines of force generated by the magnet assembly 222 on the coil layer 213b can be effectively concentrated. In this embodiment, the circuit board 213 further includes a gold layer 213g. The gold layer 213g covers the nickel layer 213f. By covering the nickel layer 213f with the gold layer 213g, oxidation of the nickel layer 213f can be avoided. In this embodiment, the nickel layer 213f and the gold layer 213g are embedded in the solder mask layer 213e. The circuit board 213 further includes a cover layer 213h with insulating function. The cover layer 213h covers the gold layer 213g to prevent the gold layer 213g from being exposed from the solder mask layer 213e.

[0036] As shown in Figures 2 and 8, in this embodiment, the first component 210 further includes a plurality of force sensors 214. The force sensors 214 are disposed on the circuit board 213. The force sensors 214 are configured to generate force sensing signals in response to deformation of the circuit board 213 (e.g., due to a user pressing the cover plate 211). When the force sensors 214 generate force sensing signals, the processing unit 213a3 shown in Figure 7 is also configured to control the vibration module to generate different vibration forces according to the touch operation and the force sensing signals, thereby providing tactile feedback. Additionally, as shown in Figure 8, the force sensors 214 are embedded in the solder mask layer 213e, and a cover layer 213h is also covering the force sensors 214, so that the force sensors 214 are not exposed through the solder mask layer 213e.

[0037] Please refer to Figure 9, which is a top view illustrating a coil layer 213b and a magnet assembly 222 according to an embodiment of the present disclosure. As shown in Figure 9, in this embodiment, the coil layer 213b includes a first coil unit 213b1 and a second coil unit 213b2 connected together. The first coil unit 213b1 and the second coil unit 213b2 are electrically coupled to an external controller (not shown). By making the distance S2 between the two coil units of the coil layer 213b substantially equal to the line spacing P of the coil units (i.e., there is no pre-reserved assembly tolerance between the first coil unit 213b1 and the second coil unit 213b2), the area utilization of the circuit board 213 can be improved.

[0038] As shown in Figure 9 and referring to Figure 2, in this embodiment, the magnet assembly 222 includes a first magnet 222a, a second magnet 222b, and a third magnet 222c. The first magnet 222a has a first magnetic pole. The first magnetic pole faces the first coil unit 213b1 in the arrangement direction D (referring to Figure 2). The second magnet 222b has a second magnetic pole. The second magnetic pole faces the second coil unit 213b2 in the arrangement direction D. The third magnet 222c has a third magnetic pole. The third magnetic pole faces the gap G between the first coil unit 213b1 and the second coil unit 213b2 in the arrangement direction D. The third magnet 222c is seamlessly arranged side by side between the first magnet 222a and the second magnet 222b. The polarity of the third magnetic pole is different from the polarity of the first magnetic pole and the polarity of the second magnetic pole. In the aforementioned design where there is no pre-reserved assembly tolerance between the first coil unit 213b1 and the second coil unit 213b2, the two magnets can be seamlessly arranged side by side by having the two adjacent magnets of the magnet assembly 222 (i.e., the first magnet 222a and the third magnet 222c, or the second magnet 222b and the third magnet 222c) face the first coil unit 213b1 and the second coil unit 213b2 with their magnetic poles of opposite polarities respectively.

[0039] Specifically, as shown in Figure 9, the first coil unit 213b1 and the second coil unit 213b2 have the same winding method and are connected in series. The first coil unit 213b1 includes two straight sections 213b11 and 213b12. The straight sections 213b11 and 213b12 are arranged side by side. The second coil unit 213b2 includes two straight sections 213b21 and 213b22. The straight sections 213b21 and 213b22 are arranged side by side. The first magnet 222a is located below a portion of the straight section 213b11 (in the lower half of Figure 9) and a portion of the straight section 213b12 (in the upper half of Figure 9), and the polarity of the first magnetic end facing the straight sections 213b11 and 213b12 is N pole. The second magnet 222b is located below a portion of the straight beam segment 213b21 (in the lower half of Figure 9) and a portion of the straight beam segment 213b22 (in the upper half of Figure 9), and its polarity toward the second magnetic end of the straight beam segments 213b21 and 213b22 is N (north). The third magnet 222c is located below a portion of the straight beam segment 213b12 (in the lower half of Figure 9), a portion of the straight beam segment 213b21 (in the upper half of Figure 9), and below the gap G between the first coil unit 213b1 and the second coil unit 213b2, and its polarity toward the third magnetic end of the straight beam segments 213b12 and 213b21 is S (south). Current flows in from the outer edge contact of the second coil unit 213b2 (located in the lower right of Figure 9) and flows out from the inner edge contact of the second coil unit 213b2. Next, the current flowing out of the second coil unit 213b2 flows into the first coil unit 213b1 through the outer edge contact (located at the center right side of Figure 9) (via the bottom pull wire), and flows out through the inner edge contact (via the bottom pull wire). With the above configuration, the magnet assembly 222 and the coil layer 213b can form a vertical vibration module.

[0040] Please refer to Figure 10, which is a top view illustrating a coil layer 213b and a magnet assembly 322 according to another embodiment of this disclosure. As shown in Figure 10, in this embodiment, the magnet assembly 322 includes a first magnet 322a and a second magnet 322b. The first magnet 322a has a first magnetic end. The first magnetic end faces the first coil unit 213b1 in the arrangement direction D. The second magnet 322b has a second magnetic end. The second magnetic end faces the second coil unit 213b2 in the arrangement direction D. The first magnet 322a and the second magnet 322b are seamlessly arranged side by side. The polarity of the first magnetic end is different from the polarity of the second magnetic end. In the aforementioned design where there is no pre-reserved assembly tolerance between the first coil unit 213b1 and the second coil unit 213b2, the first magnet 322a and the second magnet 322b can be seamlessly arranged side by side by having the first magnet 322a and the second magnet 322b face the first coil unit 213b1 and the second coil unit 213b2 respectively with their magnetic ends of opposite polarities.

[0041] Specifically, as shown in Figure 10, the first magnet 322a is located below the straight beam segments 213b11 and 213b12, and the polarity of the first magnetic end facing the straight beam segments 213b11 and 213b12 is N pole. The second magnet 322b is located below the straight beam segments 213b21 and 213b22, and the polarity of the second magnetic end facing the straight beam segments 213b21 and 213b22 is S pole. Current flows in from the inner edge contact of the second coil unit 213b2 and flows out from the outer edge contact of the second coil unit 213b2 (located at the lower right of Figure 10). Then, the current flowing out of the second coil unit 213b2 flows in again from the outer edge contact of the first coil unit 213b1 (located at the center right of Figure 10) (via the bottom pull wire), and flows out from the inner edge contact of the first coil unit 213b1 (via the bottom pull wire). With the aforementioned configuration, the magnet assembly 322 and the coil layer 213b can also form a vertical vibration module.

[0042] Please refer to Figure 11, which is a cross-sectional schematic diagram illustrating a touchpad device 300 according to another embodiment of the present disclosure. As shown in Figure 11, in this embodiment, the touchpad device 300 is disposed within the host 110 and exposed by a recess 111a in the housing portion 111 of the host 110. The touchpad device 300 includes a cover plate 211, a circuit board 313, a bonding layer 312, a plurality of force detection units 320, a feedback component 330, a support member 221, and a plurality of elastic members 230, wherein the cover plate 211, the support member 221, and the elastic members 230 are the same as those in the embodiment shown in Figure 2, and therefore details of these components can be found in the foregoing description. The cover plate 211 has a bonding area 211a and a non-bonding area 211b. The circuit board 313 is disposed under the cover plate 211 and has a first surface 313a facing the cover plate 211 and a second surface 313b away from the cover plate 211. A bonding layer 312 is disposed between the cover plate 211 and the first surface 313a, and includes a bonding portion 312a and a plurality of cutout portions 312b. A force detection unit 320 is disposed on the second surface 313b. The force detection unit 320 is disposed in the arrangement direction D of the cover plate 211 and the bonding layer 312, corresponding to both the bonding portion 312a and the cutout portions 312b. A feedback component 330 is disposed on the second surface 313b and configured to provide tactile feedback. A support member 221 is disposed under the circuit board 313. An elastic member 230 is disposed between the circuit board 313 and the support member 221.

[0043] For example, the joint area 211a of the cover plate 211 can be defined by the area where the bottom surface of the cover plate 211 is joined to the joint portion 312a of the joint layer 312, while the non-joint area 211b of the cover plate 211 can be defined by the area where the bottom surface of the cover plate 211 is not joined to the joint portion 312a of the joint layer 312 (i.e., the corresponding cutout portion 312b), but this disclosure is not limited thereto.

[0044] Please refer to Figure 12, which is a top view showing some components of the touchpad device 300 in Figure 11. As shown in Figures 11 and 12, in this embodiment, the elastic member 230 corresponds to the cutout portion 312b in the arrangement direction D of the cover plate 211 and the bonding layer 312. It should be noted that by providing the cutout portion 312b on the bonding layer 312 provided between the cover plate 211 and the circuit board 313, and making the elastic member 230, which serves as a fulcrum, correspond to the cutout portion 312b in the arrangement direction D of the cover plate 211 and the bonding layer 312, the touchpad device 300 can have better deformation for vertical vibration, thereby achieving the effect of enhancing vertical vibration.

[0045] In some embodiments, the size and material of the bonding layer 312 may be the same as those shown in Figure 2, and therefore can be referred to the foregoing description, which will not be repeated here.

[0046] In some embodiments, the feedback component 330 is a linear resonant actuator (LRA), but this disclosure is not limited thereto. In some embodiments, the feedback component 330 may include a coil layer 213b disposed on the circuit board 213 and a magnet assembly 222 disposed on the support member 221 in the embodiment shown in Figure 2. In other words, the combination of the circuit board 313 and the feedback component 330 in this embodiment is interchangeable with the combination of the circuit board 213, the coil layer 213b and the magnet assembly 222 in the embodiment shown in Figure 2. Therefore, the specific embodiments of the combination of the circuit board 213, the coil layer 213b and the magnet assembly 222 described above can be implemented in the touchpad device 300 of this embodiment, and will not be repeated here.

[0047] Please refer to Figures 13 and 14. Figure 13 is an enlarged view of region M in Figure 12. Figure 14 is an enlarged view of region M in Figure 12 in another embodiment. As shown in Figures 13 and 14, each force detection unit 320 includes a plurality of adjacent strain electrodes 321a and a plurality of temperature compensation electrodes 321b. The strain electrodes 321a are simultaneously disposed corresponding to the joint portion 312a and the hollow portion 312b in the arrangement direction D of the cover plate 211 and the bonding layer 312. That is, the strain electrodes 321a simultaneously span the lower part of the joint portion 312a and the lower part of the hollow portion 312b. In this way, the deformation of the strain electrodes 321a when the cover plate 211 of the touch panel device 300 is pressed can be increased, thereby significantly improving the sensitivity.

[0048] In the embodiment shown in Figure 13, the temperature compensation electrode 321b is disposed corresponding to the cutout portion 312b in the arrangement direction D of the cover plate 211 and the bonding layer 312. That is, the temperature compensation electrode 321b is completely located below the cutout portion 312b and does not extend beyond the bonding portion 312a. In the embodiment shown in Figure 14, the temperature compensation electrode 321b is disposed corresponding to the bonding portion 312a in the arrangement direction D of the cover plate 211 and the bonding layer 312. That is, the temperature compensation electrode 321b is completely located below the bonding portion 312a and does not extend beyond the cutout portion 312b. In this way, strain on the temperature compensation electrode 321b can be avoided, thereby providing an accurate temperature change reference.

[0049] Please refer to Figure 15, which is a circuit diagram illustrating the force detection unit 320 in Figure 12. In this embodiment, the strain electrode 321a and the temperature compensation electrode 321b of the force detection unit 320 form a Wheatstone bridge circuit as shown in Figure 15, but this disclosure is not limited thereto. The strain electrode 321a is mainly used to sense pressure changes. The temperature compensation electrode 321b is used as a temperature compensation electrode for the strain electrode 321a when compensating for temperature changes, so that the Wheatstone bridge can achieve bridge balance when the temperature changes.

[0050] In some embodiments, as shown in Figure 12, the cutout portion 312b corresponds to the force detection unit 320 in the arrangement direction D of the cover plate 211 and the bonding layer 312, respectively. That is, the number of cutout portions 312b and force detection units 320 is the same. In some embodiments, each cutout portion 312b corresponds to a plurality of force detection units 320 in the arrangement direction D. For example, the bonding layer 312 shown in Figure 12 can be modified with reference to Figure 3 to have two cutout portions 312b, one above the other, and each cutout portion 312b corresponds to four force detection units 320 in the arrangement direction D. In practical applications, the number of detection units corresponding to each cutout portion 312b in the arrangement direction D can be flexibly adjusted. For example, the bonding layer 312 may also have only one cutout portion 312b corresponding to all detection units in the arrangement direction D.

[0051] Please refer to Figures 16A, 16B, 16C, and 16D, which are enlarged views illustrating region M in Figure 12 in the first comparative example, second comparative example, third comparative example, and fourth comparative example, respectively. As shown in Figure 16A, in the first comparative example, the force detection unit 320 is completely located below the joint portion 312a in the arrangement direction D of the cover plate 211 and the bonding layer 312, and is separated from the cutout portion 312b. In the second comparative example, the force detection unit 320 is completely located below the joint portion 312a in the arrangement direction D, and is aligned with the boundary between the cutout portion 312b and the joint portion 312a. In the third comparative example, the force detection unit 320 is completely located below the cutout portion 312b in the arrangement direction D, and is aligned with the boundary between the cutout portion 312b and the joint portion 312a. In the fourth comparative example, the force detection unit 320 is located completely below the cutout portion 312b in the arrangement direction D of the cover plate 211 and the bonding layer 312, and is separated from the bonding portion 312a. Therefore, it can be seen that in the first, second, third, and fourth comparative examples, the force detection unit 320 does not span across the bonding portion 312a and the cutout portion 312b.

[0052] Please refer to Figure 17, which is a pressure output signal diagram illustrating the touchpad device 300 designed using the embodiment shown in Figure 13, the first comparative example, the second comparative example, the third comparative example, and the fourth comparative example, respectively. Figure 17 is a pressure output signal diagram obtained by pressing the cover plate 211 of the touchpad device 300 with a force of 150g. As shown in Figure 17, the signal strength of the first comparative example is the smallest, the signal strength of the embodiment shown in Figure 13 is the largest, and the signal strengths of the second, third, and fourth comparative examples are between the largest and the smallest. Therefore, by arranging the strain electrode 321a in the arrangement direction D of the cover plate 211 and the bonding layer 312 simultaneously corresponding to the bonding portion 312a and the hollow portion 312b of the bonding layer 312 (i.e. spanning the bonding portion 312a and the hollow portion 312b), the deformation of the strain electrode 321a when the cover plate 211 of the touch panel device 300 is pressed can indeed be increased, thereby significantly improving the sensitivity.

[0053] From the detailed description of the specific embodiments disclosed above, it is evident that in the touchpad device disclosed herein, since the force detection unit includes both a strain electrode and a temperature compensation electrode, it has a built-in temperature compensation function, thereby solving the detection deviation problem caused by thermal effects. By arranging the strain electrode in the arrangement direction of the cover plate and the bonding layer simultaneously corresponding to the joint portion and the hollow portion of the bonding layer (i.e., spanning the joint portion and the hollow portion), the deformation of the strain electrode when the cover plate of the touchpad device is pressed can be increased, thereby significantly improving sensitivity. By arranging the temperature compensation electrode in the arrangement direction of the cover plate and the bonding layer corresponding to either the joint portion or the hollow portion (i.e., not spanning the joint portion and the hollow portion), strain can be avoided, thereby providing an accurate temperature change reference.

[0054] Although the present disclosure has been disclosed above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0017] To make the above and other objects, features, advantages and embodiments of this disclosure more apparent and understandable, the accompanying drawings are described as follows: Figure 1 is a schematic diagram illustrating an electronic device according to an embodiment of this disclosure. Figure 2 is a cross-sectional schematic diagram illustrating the touchpad device in Figure 1. Figure 3 is a top view illustrating some components of the touchpad device in Figure 2. Figure 4 is a schematic diagram illustrating the touch electrode layer of the touch sensing element in Figure 2. Figure 5 is a partially enlarged view illustrating the first touch electrode layer in Figure 4. Figure 6 is another partially enlarged view illustrating the first touch electrode layer in Figure 4. Figure 7 is a functional block diagram illustrating the touch sensing element according to an embodiment of this disclosure. Figure 8 is a cross-sectional schematic diagram illustrating the circuit board in Figure 2. Figure 9 is a top view illustrating the coil layer and magnet assembly according to an embodiment of this disclosure. Figure 10 is a top view illustrating the coil layer and magnet assembly according to another embodiment of this disclosure. Figure 11 is a cross-sectional schematic diagram illustrating the touchpad device according to another embodiment of this disclosure. Figure 12 is a top view showing some components of the touchpad device in Figure 11. Figure 13 is an enlarged view of region M in Figure 12. Figure 14 is an enlarged view of region M in Figure 12 in another embodiment. Figure 15 is a circuit diagram of the force detection unit in Figure 12. Figure 16A is an enlarged view of region M in Figure 12 in a first comparative example. Figure 16B is an enlarged view of region M in Figure 12 in a second comparative example. Figure 16C is an enlarged view of region M in Figure 12 in a third comparative example. Figure 16D is an enlarged view of region M in Figure 12 in a fourth comparative example. Figure 17 is a diagram showing the pressure output signal of the touchpad device using the design of the embodiment shown in Figure 13, the first comparative example, the second comparative example, the third comparative example, and the fourth comparative example, respectively. [Biomaterial Storage]

[0056] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A touchpad device, comprising: a cover plate; a circuit board disposed under the cover plate and having a first surface facing the cover plate and a second surface away from the cover plate; a bonding layer disposed between the cover plate and the first surface and including a bonding portion and at least one cutout portion; a plurality of force detection units disposed on the second surface, each of the force detection units including a plurality of adjacent strain electrodes and a plurality of temperature compensation electrodes, wherein the strain electrodes are simultaneously disposed opposite to the bonding portion and the at least one cutout portion in an arrangement direction of the cover plate and the bonding layer, and the temperature compensation electrodes are disposed opposite to one of the bonding portion and the at least one cutout portion in the arrangement direction, wherein the strain electrodes and temperature compensation electrodes of each of the force detection units form a bridge circuit; and a feedback component disposed on the second surface and configured to provide tactile feedback.

2. The touchpad device as claimed in claim 1, wherein the at least one cutout is a closed slot.

3. The touchpad device as claimed in claim 1, wherein the number of the at least one cutout is plurality of, and the cutouts correspond to the force detection units respectively in the arrangement direction.

4. The touchpad device as claimed in claim 3, wherein the number of the at least one cutout is plurality of, and each of the cutouts corresponds to a plurality of the force detection units in the arrangement direction.

5. The touchpad device as claimed in claim 1, further comprising: a support member disposed under the circuit board; and a plurality of elastic members disposed between the circuit board and the support member.

6. The touchpad device as claimed in claim 5, wherein the elastic elements are provided corresponding to at least one cutout in the arrangement direction.

7. The touchpad device as claimed in claim 5, wherein the feedback component includes a coil layer and a magnet assembly.

8. The touchpad device as claimed in claim 7, wherein the coil layer is disposed on the circuit board and the magnet assembly is disposed on the support.

9. The touchpad device as claimed in claim 1, wherein the feedback component is a linear motor.

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