CN110832446A

CN110832446A - Touch sensor structure and information terminal housing

Info

Publication number: CN110832446A
Application number: CN201780092779.6A
Authority: CN
Inventors: 芝贤一; 小泷浩; 山野裕之
Original assignee: Yamaha Corp
Current assignee: Yamaha Corp
Priority date: 2017-09-13
Filing date: 2017-09-13
Publication date: 2020-02-21
Anticipated expiration: 2037-09-13
Also published as: CN110832446B; WO2019053800A1; JP6795101B2; JPWO2019053800A1

Abstract

Provided is a touch sensor structure which can suppress peeling of PET films from each other and improve sensor strength. The capacitive sensor diaphragm 20 is formed by laminating a first PET film 21 having an electrode pattern 24 and a second PET film 22 having an electrode pattern 25. The first resin layer 11 is fixed to the first surface 20a of the sensor diaphragm 20. The second resin layer 12 is fixed to the second surface 20b of the sensor diaphragm 20, and is fixed to the first resin layer 11 through the through hole 23 of the sensor diaphragm 20.

Description

Touch sensor structure and information terminal housing

Technical Field

The present invention relates to a touch sensor structure having a capacitive sensor diaphragm formed by laminating a plurality of PET (polyethylene terephthalate) films, and a housing for an information terminal having the touch sensor structure.

Background

Capacitive sensor diaphragms suitable for display units and operation units of various electronic devices have been known. The sensor membrane is configured by, for example, laminating two PET films each having an electrode pattern formed thereon by printing with a conductive ink or the like (for example, non-patent document 1 below). A structure in which a sensor diaphragm is formed on the surface of a resin molded product is also known (patent document 1 below).

Documents of the prior art

Patent document

Patent document 1: japanese unexamined patent publication No. 2017-56624

Non-patent document

Non-patent document 1: "NISSHA", "online", device, capacitive touch sensor [ 9.5.2017 retrieval, internet < URL: http:// www.nissha.com/products/dev/cap. html >)

Disclosure of Invention

Technical problem to be solved by the invention

However, for the purpose of protection, touch, or decoration, a resin portion such as a rubber material is disposed in a structure in which a sensor membrane to which two PET films are bonded is fixed to a resin base material such as plastic. For example, a resin portion such as a rubber material is fixed to the upper surface of the PET film by bonding or molding. As a result, the fixing force between the two PET films in the layer of the entire product is relatively weak, and peeling between the PET films is likely to occur. There is also a problem that peeling occurs due to continuous use of the product, and the strength as a sensor becomes low.

The invention aims to provide a touch sensor structure which can inhibit PET films from being separated from each other and improve the sensor strength.

Technical solution for solving technical problem

In order to achieve the above object, according to the present invention, there is provided a touch sensor structure comprising: a capacitive sensor diaphragm (20) formed by laminating a plurality of PET films (21,22) on which electrode patterns (24,25) are formed, and having at least one through hole (23) formed therein; a first resin layer (11) fixed to a first surface (20a) of the sensor diaphragm; and a second resin layer (12) which is fixed to the second surface (20b) of the sensor diaphragm and is fixed to the first resin layer through the through hole. The reference numerals in parentheses above are merely exemplary.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, peeling between PET films can be suppressed, and sensor strength can be improved.

Drawings

Fig. 1 is a perspective view of a housing for an information terminal having a touch sensor structure.

Fig. 2 is a perspective view of the first resin layer.

Fig. 3 is a perspective view of a PET film constituting a sensor diaphragm.

Fig. 4 is a perspective view of the laminate.

Fig. 5 is a partial cross-sectional view of the housing.

Fig. 6A is a partial sectional view of the housing of the first modification.

Fig. 6B is a partial sectional view of the housing of the second modification.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a perspective view of a housing for an information terminal having a touch sensor structure according to an embodiment of the present invention. The housing 100 is configured as a protective housing attached to the back side of a smartphone, for example. The housing 100 is attached so that a main section 100a having a large area faces the back surface of the smartphone and a side section 100c connected from the main section 100 via a bent section 100b covers the side surface of the smartphone. The housing 100 is mainly a three-layer structure in which the first resin layer 11, the sensor diaphragm 20, and the second resin layer 12 are stacked. The power supply and signal output terminal 26 extending from the sensor diaphragm 20 is exposed from the inside of the side portion 100 c.

Fig. 2 is a perspective view of the first resin layer 11. The first resin layer 11 is made of plastic such as polyethylene, for example. A plurality of convex portions 14 are formed to protrude from a first surface 11a of the first resin layer 11 facing the sensor diaphragm 20. A step portion 11b is formed on an outer portion of the first resin layer 11 corresponding to each side portion 100 c. Fig. 3 is a perspective view of a PET film constituting the sensor diaphragm 20. The sensor diaphragm 20 is formed by laminating a first PET film 21 and a second PET film 22. A plurality of transparent electrode patterns 24 are arranged substantially parallel to each other on the first PET film 21. A plurality of transparent electrode patterns 25 are arranged substantially parallel to each other on the second PET film 22. In the sensor membrane 20 after lamination, the electrode pattern 24 is substantially orthogonal to the electrode pattern 25. The

PET films

21 and 22 are provided with through holes 23 corresponding to the projections 14. The through-hole 23 is formed at a position avoiding the electrode patterns 24, 25.

The sensor diaphragm 20 is a flexible touch sensor diaphragm of a capacitive type. When the pressing force is applied, the touch position in the X-Y direction is detected from the change in capacitance in each of the arrangement direction (for example, the X direction) of the electrode pattern 24 and the arrangement direction (for example, the Y direction) of the electrode pattern 25. The method of disposing the electrode patterns 24 and 25 is not particularly limited, and for example, the electrode patterns can be formed by printing conductive ink or the like.

Fig. 4 is a perspective view of a laminate in which the sensor membrane 20 is laminated on the first resin layer 11. The laminate 30 is formed by fixing the sensor membrane 20 to the first surface 11a of the first resin layer 11. The fixing method of both is not limited, and can be performed by, for example, adhesion. When the both are fixed to each other, each of the convex portions 14 is inserted into the corresponding through hole 23, thereby positioning the sensor diaphragm 20 with respect to the first resin layer 11 (positioning in the X-Y direction and the rotational direction of the axis orthogonal to the X-Y direction). The edge 20c of the sensor diaphragm 20 is close to or in contact with the step 11b of the first resin layer 11. The second resin layer 12 is made of, for example, an elastomer. The second resin layer 12 is formed by, for example, compression molding, and is fixed to the laminated body 30.

Fig. 5 is a partial sectional view of the housing 100. Fig. 5 shows a cross section of one projection 14. The same applies to the other convex portions 14, and the configuration of the periphery of the convex portion 14. In fig. 5, the electrode patterns 24 and 25 are not shown. The first surface 11a of the first resin layer 11 is fixed to the first surface 20a of the sensor diaphragm 20. The second surface 20b of the sensor diaphragm 20 is fixed to the surface 12a of the second resin layer 12. The end surface of the convex portion 14 is substantially flush with the second surface 20b of the sensor diaphragm 20. The end face of the projection 14 is fixed to the surface 12a of the second resin layer 12. Since the first resin layer 11 and the second resin layer 12 are in a fixed relationship by the through-hole 23, a force that separates the

PET films

21 and 22 is less likely to act on the sensor diaphragm 20. Therefore, peeling between the

PET films

21,22 hardly occurs.

However, if there is a gap between the projection 14 and the through hole 23 during molding of the second resin layer 12, it is assumed that the second resin layer 12 enters the gap. Thus, there is a problem that the second resin layer 12 enters between the

PET films

21 and 22 from the inner edge of the through-hole 23. Then, a seal portion 27 is provided around each through hole 23 of the

PET films

21 and 22. The sealing portion 27 is realized by, for example, using heat-sealing the

PET films

21 and 22, but is not limited thereto, and may be formed by adhesion or the like. In order to avoid the second resin layer 12 from entering, a sealing portion may be provided at the edge portion 20c (fig. 4) of the sensor diaphragm 20.

Next, a method for manufacturing the housing 100 will be described. First, the worker forms the first resin layer 11 by injection molding or the like. At this time, all the convex portions 14 are also formed integrally with the first resin layer 11. The forming method of the first resin layer 11 is not limited to molding. The worker forms an electrode pattern 24 on the first PET film 21 and an electrode pattern 25 on the second PET film 22 by printing conductive ink or the like. Then, the worker attaches the first PET film 21 and the second PET film 22 by adhesion. It is not necessary to bond both of them, and only to overlap them. Then, the worker forms a through hole 23 in the

laminated PET films

21 and 22. The operator defines a position in advance and forms a hole so that the through hole 23 is formed at a position (corresponding position) avoiding the electrode patterns 24 and 25. Thereby, the sensor diaphragm 20 can be obtained. The worker may open the through-holes 23 in the

PET films

21 and 22 at a stage before the

PET films

21 and 22 are laminated.

Next, the worker fixes the first surface 20a of the sensor diaphragm 20 and the first surface 11a of the first resin layer 11 by adhesion or the like, thereby obtaining the laminated body 30. At this time, the worker positions the projection 14 and the through hole 23 corresponding to each other, and then attaches the sensor diaphragm 20 and the first resin layer 11 to each other while overlapping each other so as to fit each other. Next, the worker fixes the second surface 20b of the sensor diaphragm 20 and the surface 12a of the second resin layer 12. For example, in the case of compression molding, the worker puts an elastic body as a material into a mold into which the laminate 30 is inserted, and compresses the material while bringing the mold to a high temperature of a predetermined temperature. The elastomer is melted and then solidified, and is fixed to the convex portion 14 of the first resin layer 11 and the second surface 20b of the sensor diaphragm 20. As described above, the elastic body also enters the gap between the convex portion 14 and the through hole 23 and is cured. In this way, the second resin layer 12 is laminated and fixed to the second surface 20b side of the sensor diaphragm 20. The second resin layer 12 is not necessarily formed by compression molding, and may be formed by injection molding, for example.

When the user touches the surface of the casing 100 completed in this manner, particularly the surface of the second resin layer 12, the touched position on the surface of the second resin layer 12 is detected based on the change in the electrostatic capacitance of the electrode patterns 24, 25. The detection signal is output from the terminal portion 26. The electronic device such as an information terminal mounted with the housing 100 may communicate with the housing 100 in a wireless or wired manner.

According to the present embodiment, the second resin layer 12 is fixed to the second surface 20b of the sensor diaphragm 20, and is fixed to the first resin layer 11 through the through hole 23 of the sensor diaphragm 20. This can suppress peeling of the PET films constituting the sensor diaphragm 20, and improve the sensor strength.

Further, since the sensor diaphragm 20 is provided with the seal portion 27 that seals the PET films by surrounding the through hole 23, when the second resin layer 12 is formed by molding, the second resin layer 12 can be prevented from entering between the

PET films

21 and 22. In the sensor diaphragm 20, the through-holes 23 are arranged so as to avoid the electrode patterns 24 and 25, and therefore, an appropriate position detection function can be maintained.

Since the second resin layer 12 is made of an elastic material, in the case of using a method of forming the second resin layer 12 by molding to be fixed to the laminate 30, the second resin layer 12 can be fixed to the first resin layer 11 through the through-hole 23 during molding. From this viewpoint, the second resin layer 12 may be a synthetic resin having thermoplasticity and thermosetting properties.

The plurality of projections 14 and the plurality of through holes 23 are provided. Therefore, the sensor diaphragm 20 and the first resin layer 11 can be positioned in a direction parallel to the second surface 20b of the sensor diaphragm 20 and in a rotational direction about an axis perpendicular to the second surface 20b by the engagement of the corresponding convex portion 14 and the through hole 23.

Next, a modification will be described with reference to fig. 6A and 6B. Fig. 6A and 6B are partial sectional views of the housing 100 according to the first and second modified examples, respectively, and correspond to fig. 5. In the example shown in fig. 5, the convex portion 14 is formed in the first resin layer 11. However, the first resin layer 11 and the second resin layer 12 may be fixed to each other through the through-hole 23. Therefore, a convex portion may be provided on at least one of the first resin layer 11 and the second resin layer 12, and the convex portion inserted into the through hole 23 may be fixed to the other of the first resin layer 11 and the second resin layer 12.

In the first modification (fig. 6A), the first resin layer 11 is not provided with the convex portions, and the surface 12a of the second resin layer 12 is provided with the convex portions 13 protruding and formed so as to correspond to the through holes 23. The end surface of the projection 13 is substantially flush with the first surface 20a of the sensor diaphragm 20, and is fixed to the first surface 11a of the first resin layer 11. When the second resin layer 12 is fixed to the laminate 30 by compression molding, the elastomer is melted and filled into the through-hole 23. Thereby forming the convex portion 13. After the elastomer is cured, the surface 12a of the second resin layer 12 is fixed to the second surface 20b of the sensor diaphragm 20, and the convex portion 13 is fixed to the first surface 11a of the first resin layer 11.

In a second modification (fig. 6B), the convex portions 14 are formed to protrude from the first surface 11a of the first resin layer 11, and the convex portions 13 are formed to protrude from the surface 12a of the second resin layer 12. The

convex portions

14, 13 and the through holes 23 correspond to each other. The end face of the projection 14 is fixed to the end face of the projection 13. When the second resin layer 12 is fixedly formed by compression molding with respect to the laminate 30, the elastomer melts and fills the through-hole 23 in the region excluding the projection 14. Thereby forming the convex portion 13. After the elastomer is cured, the surface 12a of the second resin layer 12 is fixed to the second surface 20b of the sensor diaphragm 20, and the convex portion 13 is fixed to the convex portion 14.

The sensor diaphragm 20 has a structure in which two PET films are laminated, but the number of lamination may be three or more. The touch sensor structure of the present invention is not limited to the housing for an information terminal, and can be applied to various electronic devices.

Description of the reference numerals

11a first resin layer;

12a second resin layer;

13,14 protrusions;

20a sensor diaphragm;

20a first side;

20b a second face;

21 a first PET film;

22 a second PET film;

23 through holes;

24,25 electrode patterns;

27 sealing the portion.

Claims

1. A touch sensor structure comprising:

a capacitive sensor diaphragm formed by laminating a plurality of PET films each having an electrode pattern formed thereon, and having at least one through hole formed therein;

a first resin layer fixed to a first surface of the sensor diaphragm;

and a second resin layer fixed to the second surface of the sensor diaphragm and fixed to the first resin layer through the through hole.

2. The touch sensor construction of claim 1,

a projection portion inserted into the through hole is formed on at least one of the first resin layer and the second resin layer, and the projection portion is fixed to the other of the first resin layer and the second resin layer.

3. The touch sensor construction of claim 1 or 2,

the sensor diaphragm is provided with a sealing portion that surrounds the through hole and seals the PET films.

4. The touch sensor construction of any of claims 1-3,

in the sensor membrane, the through-hole is arranged so as to avoid the electrode pattern.

5. The touch sensor construction of any of claims 1-4,

the second resin layer is formed of an elastomer.

6. An information terminal housing having the touch sensor structure according to any one of claims 1 to 5.