Touch panel

Abstract

To provide a touch panel capable of achieving high designability with a simple structure.SOLUTION: In a touch panel 10, a concave portion 34 is provided as a positioning structure for positioning the first electrode substrate 14 with respect to a case 20 on the lower surface of a first electrode substrate 14, and on the inner bottom of the case 20, a convex portion 36 such as a boss or rib is formed, the substrate assembly 26 is positioned with respect to the case 20 by engaging a recess 34 and the protrusion 36 and fixed with an adhesive layer 28.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a touch panel provided with a case.

Background Art

[0002] Various touch panels such as a resistive film type, a capacitance type, and an electrostatic coupling type are known. For example, in a resistive film type touch panel, there is one in which conductive pins are inserted into through holes of a glass substrate to conductively connect a resistive film and an external terminal (see, for example, Patent Document 1). Further, an irregular display having a structure in which holes are formed in both a liquid crystal panel and a lower cover, and a cylindrical guide means is provided in the holes to fix an optical sheet is known (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been an increasing need for a touch panel that emphasizes design and has a structure that does not use a bezel or a front case that decorates the operation surface and covers the outer peripheral portion of the electrode substrate. However, such a touch panel, while having high design, makes it difficult to accurately position and fix a substrate assembly having an operation surface with respect to a case, and a relatively large gap is generated between the operation surface and the case, which may deteriorate the appearance of the touch panel.

[0005] Therefore, an object of the present invention is to provide a touch panel that realizes high design with a simple configuration.

Means for Solving the Problems

[0006] One aspect of the present disclosure includes a first electrode substrate having a first conductive film, a second electrode substrate having a second conductive film facing the first conductive film, and a positioning structure for positioning the first electrode substrate with respect to a case that houses the first electrode substrate. The positioning structure is formed on the first electrode substrate and does not reach the second electrode substrate and has a recess, and the recess engages with a protrusion provided on the case, and is a touch panel.

Advantages of the Invention

[0007] According to the present disclosure, an aesthetic appearance is not deteriorated due to a gap between the case and the operation surface, and a touch panel with high design quality is provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, the same or similar elements are denoted by common reference numerals for easy understanding, and these drawings have their scales appropriately changed.

[0010] (First Embodiment) FIG. 1 is a schematic top view of a touch panel 10 according to the first embodiment, FIG. 2 is an exploded perspective view of the touch panel 10 of FIG. 1, FIG. 3 is a cross-sectional view taken along line A-A′ of the touch panel 10 of FIG. 1, and FIG. 4 is an enlarged view of part B in FIG. 3. The touch panel 10 includes a first electrode substrate 14 having an ITO (Indium Tin Oxide) 12 as a first conductive film, a second electrode substrate 18 having an ITO 16 as a second conductive film facing the ITO 12, and a case 20 housing the first electrode substrate 14 and the second electrode substrate 18. In this embodiment, the first electrode substrate 14 is a glass substrate, and the second electrode substrate 18 is a resin film substrate such as PET (Polyethylene terephthalate).

[0011] The second electrode substrate 18 has a conductive decoration portion 22. The decoration portion 22 is formed in a frame shape as a design print. Also, the outer dimensions of the decoration portion 22 substantially coincide with the outer dimensions of the second electrode substrate 18. The decoration portion 22 is adhered to the first electrode substrate 14 by an adhesive layer 24 such as a double-sided adhesive tape, and as a result, a substrate assembly 26 including the first electrode substrate 14 and the second electrode substrate 18 is formed.

[0012] The lower part of the first electrode substrate 14 is fixed to the case 20 by an adhesive layer 28 such as a double-sided adhesive tape. The case 20 is integrally formed by injection molding of resin or the like. The touch panel 10 is of a type that does not have a so-called bezel or front case. To enhance the design property, the first electrode substrate 14 and the second electrode substrate 18 have substantially the same outer dimensions, and the upper end surface 30 of the case 20 is substantially at the same height as the operation surface 32 of the second electrode substrate 18. Note that a display (not shown) such as an LCD or an organic EL panel may be provided below the first electrode substrate 14.

[0013] FIG. 5 is a schematic top view of a touch panel 110 according to a comparative example, and FIG. 6 is a cross-sectional view taken along line C-C' of the touch panel 110 of FIG. 5. The touch panel 110 is also of a type without a so-called bezel or front case, and the upper end surface 130 of the case 120 is substantially at the same height as the operation surface 132 of the second electrode substrate 118. The first electrode substrate 114 and the second electrode substrate 118 have substantially the same outer dimensions, and the two members are adhered to each other with a double-sided adhesive tape 124 or the like to form a substrate assembly 126. The outer dimensions of the decorative portion 122 formed on the second electrode substrate 118 by printing or the like are substantially equal to the outer dimensions of the second electrode substrate 18. Further, the inner dimensions of the case 120 are set to be slightly larger than the outer dimensions of the first electrode substrate 114, and the two members are adhered to each other with a double-sided adhesive tape 128 or the like.

[0014] In the touch panel 110, the substrate assembly 126 is fixed in the case 120 by dropping the substrate assembly 126 into the case 120 from above. Therefore, as described above, it is necessary to set the inner dimensions of the case 120 to be slightly larger than the outer dimensions of the second electrode substrate 118 and provide some gaps between the two members. However, it has been difficult to position and fix the first electrode substrate 14 to the case 120 so that the gaps between the second electrode substrate 118 and the case 120 are uniform on all four sides of the touch panel 110.

[0015] Specifically, in the touch panel 110, when mounting the substrate assembly 126 in the case 120, first, an operation of abutting the outer surface of the substrate assembly 126 against a part of the inner surface of the case 120 is performed. For example, in FIG. 5, since the substrate assembly 126 is abutted against the upper left part 133 of the case 120, if the substrate assembly 126 is fixed as it is, a gap 137 will be generated between the case 120 and the substrate assembly 126 at the lower right part 135 of the case 120. If the width of this gap is about 0.5 mm to 1 mm, the user can visually recognize the gap, and the appearance of the touch panel will deteriorate. There is also a risk that foreign matter or the like will enter from the gap and the function of the touch panel will be adversely affected.

[0016] Therefore, in the first embodiment, as a positioning structure for positioning the first electrode substrate 14 with respect to the case 20, a recess 34 is provided on the lower surface of the first electrode substrate 14, and a convex portion 36 such as a boss or a rib is provided on the inner bottom surface of the case 20. By engaging the recess 34 and the convex portion 36, the substrate assembly 26 is positioned with respect to the case 20 and fixed with the adhesive layer 28. In this way, when mounting the substrate assembly on the case as in the comparative example, there is no need to abut against the inner surface of the case. Therefore, the substrate assembly 26 is not unevenly distributed within the case 20, and a highly designed touch panel 10 with a uniform gap between the second electrode substrate 18 and the case 20 over the entire circumference as shown in FIG. 1 is provided.

[0017] In the illustrated example, the recess 34 is a through hole extending in a direction perpendicular to the surface of the first electrode substrate 14. The recess 34 does not necessarily have to penetrate the first electrode substrate 14 from the viewpoint of engagement with the convex portion 36, but from the viewpoint of ease of processing and the like, it is preferably formed as a through hole. When the recess 34 is formed as a through hole, it is desirable that the height of the convex portion 36 is smaller than the thickness of the first electrode substrate 14 so that the convex portion 36 does not contact the decorative portion 22 during assembly.

[0018] In the illustrated example, the convex portion 36 is a frustum of a cone having an upper end portion 38 with an outer diameter smaller than the inner diameter of the recess (through hole) 34 and a lower end portion 40 with an outer diameter substantially equal to the inner diameter of the recess 34, and stands on the inner bottom surface of the case 20. Here, "substantially" means that if the inner diameter of the recess 34 is slightly smaller than the outer diameter of the lower end portion 40 of the protrusion 36, the glass-made first electrode substrate 14 may be damaged during assembly. Therefore, it is desirable that the inner diameter of the recess 34 is slightly larger than the outer diameter of the lower end portion 40 of the frustum 36, but the difference is not such that the first electrode substrate 14 can be displaced in the plane direction with respect to the case 20 to a visible extent.

[0019] The decorative part 22 is made of a dark or opaque conductive carbon, and the members existing behind it cannot be visually recognized. Therefore, as shown in FIG. 4, by disposing the concave portion 34 and the convex portion 36 within the downward projection region of the decorative part 22, the concave portion 34 and the convex portion 36 are not visually recognized by the user, and the appearance of the touch panel 10 is not impaired. Also, since the air in the concave portion 34 is sealed within the space defined by the first electrode substrate 14, the case 20, the adhesive layers 24 and 28, and the decorative part 22, it does not contact the second conductive film 16 which is ITO. Thus, oxidation of the second conductive film 16 (ITO) can be prevented. Regarding the first conductive film 12, only the end face thereof comes into contact with the air in the concave portion 34, but since the area is very small, oxidation of most of the first conductive film 12 (ITO) is also prevented. Further, in order to prevent oxidation of the decorative part 22, the decorative part 22 is preferably formed from a weather-resistant material.

[0020] In the illustrated example, the concave portion 34 and the convex portion 36 are each formed at two locations substantially in the center of the short side of the touch panel 10, but the present disclosure is not limited thereto. For example, of the four corners of the touch panel 10, the concave portion 34 and the convex portion 36 may be respectively provided at two corners on one diagonal line, or may be provided at all four corners. Note that if there is one concave portion 34 and one convex portion 36 respectively, the substrate assembly may rotate and displace about the convex portion 36 when positioning and fixing the substrate assembly. Therefore, it is preferable that there are two or more concave portions 34 and convex portions 36 respectively.

[0021] FIG. 7 is a side cross-sectional view of a touch panel 10b according to a second embodiment, and FIG. 8 is an enlarged view of a portion D in FIG. 7. In the second embodiment, for components that may be the same as those in the first embodiment, the same reference numerals as those in the first embodiment are given, and detailed descriptions thereof are omitted.

[0022] In the touch panel 10b, as a positioning structure for positioning the first electrode substrate 14 with respect to the case 20, a recess 42 is provided on the lower surface of the first electrode substrate 14, and a snap fit 44 is provided as a convex portion on the inner bottom surface of the case 20. By engaging the snap fit 44 with the recess 42 in a snap manner, the substrate assembly 26 is positioned and fixed with respect to the case 20. In this way, when mounting the substrate assembly in the case as in the comparative example, there is no need to abut against the inner surface of the case. Therefore, the substrate assembly 26 is not unevenly distributed within the case 20, and a highly designed touch panel 10 is provided in which the gap between the second electrode substrate 18 and the case 20 is uniform over the entire circumference as shown in FIG. 1.

[0023] In the first embodiment, the adhesive layer 28 is used to fix the first electrode substrate 14 and the case 20. However, in the second embodiment, since the snap fit 44 has a fixing function in addition to the positioning function, the adhesive layer 28 may not be used. However, when the substrate assembly is relatively large or heavy, etc., and the fixing force between the case and the substrate assembly may be insufficient with only the snap fit, the adhesive layer 28 may be provided as shown.

[0024] The recess 42 is a through hole that penetrates the first electrode substrate 14 perpendicularly to the plane direction. The recess 42 does not necessarily have to penetrate the first electrode substrate 14 from the viewpoint of engagement with the snap fit 44, but from the viewpoint of ease of processing, etc., it is preferably formed as a through hole. Further, when the recess 42 is formed as a through hole, the height of the snap fit 44 is desirably smaller than the thickness of the first electrode substrate 14 so that the locking portion 48 does not contact the decorative portion 22 during assembly. Above the recess 42, a countersunk hole 50 that is concentric with the recess 42 and has a larger diameter than the recess 42 is formed.

[0025] The snap fit 44 has a rod-shaped base 46 erected on the inner bottom surface of the case 20 and at least two claw-shaped locking portions 48 connected to the base 46 so as to extend in opposite directions in the plane direction. The two locking portions 48 are configured to be elastically displaceable so as to approach and separate from each other in the plane direction. Further, each of the locking portions 48 in the snap fit 44 preferably has an inclined surface. In this way, when the substrate assembly 26 is mounted in the case 20, the two locking portions 48 elastically deform so as to approach each other, pass through the recess 42, and after passing through, the two locking portions 48 are displaced so as to separate from each other and lock into the countersunk hole 50. As a result, the substrate assembly 26 is accurately positioned and fixed with respect to the case 20.

[0026] The decorative portion 22 is made of a dark or opaque conductive carbon, and the members existing behind it are not visible. Therefore, as shown in FIG. 8, by arranging the snap fit 44, the recess 42, and the countersunk hole 50 within the downward projection area of the decorative portion 22, the snap fit 44, the recess 42, and the countersunk hole 50 are not visible to the user and do not impair the appearance of the touch panel 10b. Also, since the air in the recess 42 is sealed within the space defined by the first electrode substrate 14, the case 20, the adhesive layers 24 and 28, and the decorative portion 22, it does not come into contact with the second conductive film 16 which is ITO. Therefore, oxidation of the second conductive film 16 (ITO) can be prevented. Regarding the first conductive film 12, only the end surface thereof comes into contact with the air in the recess 42, but since the area is very small, oxidation of most of the first conductive film 12 (ITO) is also prevented. Also, in order to prevent oxidation of the decorative portion 22, the decorative portion 22 is preferably formed from a weather-resistant material.

[0027] The snap fit 44 and the recess 42 can each be formed at two locations approximately in the center of the short side of the touch panel 10, similar to the first embodiment shown in FIG. 2, but the present disclosure is not limited thereto. For example, of the four corners of the touch panel 10b, the snap fit 44 and the recess 42 may be provided at two corners on one diagonal line, or may be provided at all four corners. Note that if there is one snap fit 44 and one recess 42 each, the substrate assembly may rotate and displace with respect to the snap fit 44 when positioning and fixing the substrate assembly 26. Therefore, it is preferable that there are two or more snap fits 44 and recesses 42 each.

[0028] FIG. 9 is a partially enlarged view of the touch panel 10c according to the third embodiment. In the third embodiment, components that may be the same as those in the first embodiment are given the same reference numerals as in the first embodiment, and detailed descriptions thereof are omitted.

[0029] The touch panel 10c is common with the touch panel 10b in that a snap fit is used as the convex portion, but instead of passing the snap fit through the through hole as in the touch panel 10b, it is engaged with a recess 58 provided on the outer peripheral end surface of the first electrode substrate 14. Specifically, the snap fit 52 included in the touch panel 10c has a rod-shaped base portion 54 formed on the inner bottom surface of the case 20 and a claw-shaped locking portion 56 extending inward in the plane direction from the base portion 54, and the locking portion 56 is configured to be elastically displaceable in the plane direction.

[0030] It is desirable that the height of the snap fit 52 is smaller than the thickness of the first electrode substrate 14 so that the locking portion 56 does not contact the decorative portion 22 during assembly. A recess 58 capable of receiving the locking portion 56 is formed on the outer peripheral end surface of the first electrode substrate 14. In this way, when the substrate assembly 26 is mounted in the case 20, the locking portion 56 enters and engages in the recess 58, and as a result, the substrate assembly 26 is accurately positioned and fixed with respect to the case 20.

[0031] The snap fit 52 can apply a side pressure from the outer periphery toward the center to the first electrode substrate 14 in addition to the force pressing the first electrode substrate 14 against the case 20. Therefore, it is preferable that at least two snap fits 52 and recesses 58 are provided at positions opposite to each other with respect to the center of the touch panel as shown in FIG. 2, for example. In this way, the first electrode substrate 14 can be positioned and fixed to the case 20 more stably.

[0032] Since the snap fit 52 is disposed adjacent to the outer peripheral end surface of the first electrode substrate 14, there is a possibility that the snap fit 52 may be visually recognized by the user from the gap between the case 20 and the second electrode substrate 18, deteriorating the appearance of the touch panel 10b. Therefore, as shown in FIG. 9, an extended portion 60 is formed on the outer peripheral portion of the second electrode substrate 18 so as to be larger than the first electrode substrate 14, and the snap fit 52 is preferably included within the downward projection region of the dark or light-blocking decorative portion 22 formed on the second electrode substrate 18 including the extended portion 60. In this way, the snap fit 52 is not visually recognized by the user, and the appearance of the touch panel 10b is not impaired. Note that the recess 58 is preferably formed as a groove extending parallel to the side surface of the first electrode substrate 14 over the entire circumference of the outer peripheral end surface of the first electrode substrate 14 from the viewpoint of ease of processing and the like.

[0033] FIG. 10 is a partially enlarged view of the touch panel 10d according to the fourth embodiment. In the fourth embodiment, the same reference numerals as those in the third embodiment are given to the components that may be the same as those in the third embodiment, and the detailed description thereof is omitted.

[0034] The touch panel 10d is common to the touch panel 10c in that the snap fit 52 disposed adjacent to the outer peripheral end surface of the first electrode substrate 14 is used, but is different from the touch panel 10c in that it has a recess 62 deeper than the recess 58 of the touch panel 10c.

[0035] In the touch panel 10c, the recess 58 is provided with a depth capable of receiving the locking portion 56. In the touch panel 10d, the recess 62 has a depth capable of receiving not only the locking portion 56 but also the base portion 54. Therefore, in the touch panel 10d, when the snap fit 52 engages with the recess 62 formed in the first electrode substrate 14, the snap fit 52 will be included within the downward projection region of the dark or light-blocking decorative portion 22 formed in the second electrode substrate 18. Thus, in the fourth embodiment, there is no need to form the extended portion 60 so that the second electrode substrate 18 is larger than the first electrode substrate 14 as in the touch panel 10c.

[0036] Note that, similar to the recess 58 of the touch panel 10c, the recess 62 is preferably formed as a groove extending parallel to the side surface of the first electrode substrate 14 over the entire circumference of the outer peripheral end surface of the first electrode substrate 14 from the viewpoint of ease of processing and the like.

[0037] In the third and fourth embodiments, since the snap fit has a fixing function in addition to the positioning function, the adhesive layer 28 is not necessarily required. However, when the substrate assembly is relatively large or heavy, etc., and the fixing force between the case and the substrate assembly may be insufficient with only the snap fit, the adhesive layer 28 may be provided as shown.

[0038] In any of the first to fourth embodiments, examples of the processing method for forming the recess in the first electrode substrate 14 include laser drilling, water jet machining, polishing (grinding stone) machining, ultrasonic machining, polishing, or a combination thereof. Further, examples of the method for forming convex portions such as bosses and snap fits in the case 20 include integrally forming the case 20 by resin injection molding or the like. However, after forming the case 20 without convex portions by injection molding or the like, a member corresponding to the convex portion may be attached with an adhesive or the like.

[0039] Although all of the above embodiments have been described with respect to a resistive film type touch panel, the present disclosure is not limited thereto. For example, the touch panel according to the present disclosure may be a capacitance type or an electrostatic coupling type, or in the case of a resistive film type, it may be any of a 4-wire type, 5-wire type, 7-wire type, 8-wire type, etc. Further, ITO may be replaced with a conductive polymer or the like.

Description of Reference Numerals

[0040] 10, 10b, 10c, 10d, 110 Touch panel, 12 ITO, 14 First electrode substrate, 16 ITO, 18 Second electrode substrate, 20 Case, 22 Decorative part, 24, 28 Adhesive layer, 26 Substrate assembly, 34, 42 Recess, 36 Boss, 44, 52 Snap fit, 50 Countersink hole, 58, 62 Groove

Claims

1. A first electrode substrate having a first conductive film, A second electrode substrate having a second conductive film facing the first conductive film, A positioning structure for positioning the first electrode substrate with respect to a case that houses the first electrode substrate, and The positioning structure has a recess formed in the first electrode substrate and not reaching the second electrode substrate, and the recess engages with a protrusion provided on the case, a touch panel.

2. Further comprising a decorative portion formed on the second electrode substrate, wherein the recess and the protrusion are disposed within a downward projection region of the decorative portion, the touch panel according to claim 1.

3. The recess is a through hole extending in a direction perpendicular to the surface of the first electrode substrate, the touch panel according to claim 1 or 2.

4. A first electrode substrate having a first conductive film, A second electrode substrate having a second conductive film facing the first conductive film, A positioning structure for positioning the first electrode substrate with respect to a case that houses the first electrode substrate, and The positioning structure has a recess formed in the first electrode substrate, and the recess engages with a protrusion provided on the case, The recess is provided on an outer peripheral end surface of the first electrode substrate, a touch panel.

5. The recess has a countersunk hole for locking a locking portion provided on the protrusion, the touch panel according to any one of claims 1 to 3.

6. The second electrode substrate has an extended portion that is larger than the first electrode substrate at its outer peripheral portion, the touch panel according to claim 4.

7. The recess is a groove extending parallel to a side surface of the first electrode substrate over the entire circumference of the outer peripheral end surface of the first electrode substrate, the touch panel according to claim 4 or 6.

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