JP2011204419A - Member for input sheet and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for an input sheet with almost no gap between a through-hole and a filling material inside it on an operation surface, and its manufacturing method.SOLUTION: The member for an input sheet 2 is provided with keys 3a, 3b, 3c having one or two or more through-holes 5 penetrating in a front-and-rear direction, or a key assembly plate 3, a filling material 8 filled inside the through-holes 5 from rear surfaces of the keys 3a, 3b, 3c or the key assembly plate 3, and a sealing layer 9 at least sealing a gap between the through-holes 5 and the filling material 8 inside them.

Description

  The present invention relates to an input sheet member and a manufacturing method thereof.

  Conventionally, diversification of the design of members for input sheets used for operation units of electronic devices such as mobile phones and personal digital assistants (PDAs) has been demanded. As one form of a key sheet with excellent design, a non-translucent key sheet is formed with a through hole for displaying characters, etc. by press molding, laser etching or chemical etching, and the through hole is made transparent. What sealed resin which has property is known.

  For example, such a key sheet has a structure in which a transparent resin sheet extending from the inner surface of the through hole to the surface is provided on the back surface side, and a transparent rubber-like elastic body is filled inside the resin sheet. (For example, see Patent Document 1). When illuminated from the back side of such a key sheet, the resin sealing the through hole is transmitted, and the shape of the characters or symbols is visually recognized by the user.

JP 2007-134071 A

  Although the key sheet described in Patent Document 1 has high identification of each key even in a dark place and is excellent in design, there are the following demands in the market. When viewed from the operation surface side, there may be a gap between the inner surface of the through hole and the filled resin. In the market, the gap is reduced, so that nails are not caught when storing or using dirt. It is desired to be able to operate more smoothly.

  The present invention has been made to meet the above-mentioned demand, and an object of the present invention is to provide an input sheet member that has almost no gap between a through hole and a filler inside the operation surface, and a method for manufacturing the same. And

  In order to achieve the above object, an embodiment of an input sheet member according to the present invention includes a key or a key assembly plate having one or more through holes penetrating in the front and back direction, and a back surface of the key or key assembly plate. To the inside of the through hole, and a sealing layer that seals at least the gap between the through hole and the inside filler.

  Furthermore, the sealing layer can be formed so as to extend from the inner side surface of the through hole to the operation surface side.

  Furthermore, the sealing layer may be provided so that the depth of the gap with the inner surface of the through hole is 0.02 mm or less and the width of the gap is 0.02 mm or less.

  Furthermore, the sealing layer can be a printed layer formed by printing.

An embodiment of a method for manufacturing an input sheet member of the present invention is a method for manufacturing an input sheet member including a key or a key assembly plate having one or two or more through holes penetrating in the front and back direction. A sealing layer forming step of forming a sealing layer in the through hole portion;
And a filling step of filling a filler filled in the through hole from the back surface of the key or the key assembly plate.

  ADVANTAGE OF THE INVENTION According to this invention, the member for input sheets which has almost no clearance gap between a through-hole and the filler inside the operation surface, and its manufacturing method can be provided.

It is a front view of a mobile telephone provided with the member for input sheets which concerns on embodiment of this invention. It is a front view of the member for input sheets integrated in the mobile telephone shown in FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG. 2 for the input sheet member shown in FIG. 2. It is a flowchart which shows the schematic flow of manufacture of the member for input sheets which concerns on embodiment of this invention. FIG. 5 is a diagram illustrating a state where an operation surface side is directed to a lower side in the drawing in each step of the input sheet member in FIG. It is sectional drawing of the area | region shown by B of FIG. 3 about the member for input sheets which concerns on the modification of embodiment of this invention. It is sectional drawing of the area | region which shows the member for input sheets which concerns on another modification of embodiment of this invention by B of FIG. FIG. 4 is a diagram showing a state in which an operation surface side is directed to a lower side in the drawing in each step of the input sheet member manufacturing process according to the embodiment of the present invention, and is a cross-sectional view of a region indicated by B in FIG. .

  Next, embodiments of an input sheet member and a method for manufacturing the same according to the present invention will be described with reference to the drawings.

(Configuration of input sheet members)
FIG. 1 is a front view of a mobile phone 1 including an input sheet member 2 according to an embodiment of the present invention. FIG. 2 is a front view of the input sheet member 2 incorporated in the mobile phone 1 shown in FIG.

  As shown in FIG. 1, a mobile phone 1 that is an example of an electronic device includes an input sheet member 2 according to the present embodiment on its operation surface. In this specification, “input sheet member” refers to a member for a push button switch that switches ON / OFF by a pressing operation, and an input sheet used for an input device that can input an instruction simply by touching without pressing. Including members. Moreover, the member 2 for input sheets may be used for the decoration display part other than the area | region which a user operates.

  As shown in FIG. 2, the key sheet 3, which is an example of a key assembly plate, the center key 4, and the like are exposed on the operation surface side of the input sheet member 2. A plurality of keys are arranged on the key sheet 3 so as to be connected to the key sheet 3. Here, in FIG. 2, the key displaying “1” is “key 3a”, the key displaying “2” is “key 3b”, and the key displaying “3” is “key 3c”. When other keys are included, they are referred to as “keys 3a, 3b, 3c, etc.”. Hereinafter, the operation surface side is referred to as “front surface side”, and the surface side opposite to the operation surface is referred to as “back surface side”. Further, the distance between the front surface and the back surface of the key sheet 3 is referred to as “thickness”.

  3 is a cross-sectional view of the input sheet member 2 shown in FIG. In FIG. 2 and subsequent cross-sectional views, the thickness ratio of each member is changed from the actual ratio in consideration of easy viewing.

  The keys 3a, 3b, 3c, etc. in the key sheet 3 exposed on the surface side of the input sheet member 2 are portions pressed by the user. The key sheets 3a, 3b, 3c and the like have through holes 5 in which shapes such as letters, numbers, symbols or drawings are cut out. The through hole 5 is a hole penetrating from the front surface to the back surface of the key sheet 3.

  The key sheet 3 can be used without particular limitation as long as it has a predetermined strength. For example, stainless steel having a thickness of about 0.05 to 1.0 mm, or aluminum, nickel, gold, silver, Examples of the metal plate include copper, titanium, magnesium, and alloys thereof. Among these, stainless steel is preferable because it is thin and has high strength and can be obtained at low cost. Further, when the input sheet member 2 is used as a key sheet of a press switch member, the input sheet member 2 is preferably composed of a metal plate of about 0.1 to 0.5 mm. However, the key sheet 3 may be mainly formed of a member other than metal, for example, a resin such as polycarbonate, ceramics, glass, or a composite thereof. Further, the key sheet 3 may have a plurality of keys connected as shown in FIGS. 1 and 2, or each of the plurality of keys may be independent.

  The resin sheet 7 is disposed on the back surface side of the key sheet 3, and is a concave shape that extends from the back surface side of the key sheet 3 to the inner surface of the through hole 5 and the front surface side of the key sheet 3 at the portion of the through hole 5. It is formed as a layer having That is, the resin sheet 7 covers the inner side surface of the through hole 5, the front side opening of the through hole 5, and the back surface of the key sheet 3.

  The resin sheet 7 is preferably made of a material that is more flexible than the key sheet 3. When the resin sheet 7 is made of a flexible material, a switch member (not shown) can be easily pushed in, so that the user can obtain a good click feeling. As a material for such a resin sheet 7, a transparent sheet-like resin having spreadability, for example, an organic polymer such as polyethylene terephthalate (PET), polycarbonate (PC), silicone resin (SR), or polyurethane (PU). Examples thereof include compounds or composites thereof, and among them, polyurethane can be preferably used. A suitable thickness of the resin sheet 7 is in the range of 0.03 to 0.2 mm, more preferably in the range of 0.05 to 0.15 mm. As will be described later, the resin sheet 7 does not have a hole due to the filling of the elastic body 8 and smoothly extends into the through hole 5. However, the thickness of the resin sheet 7 may be less than 0.03 mm or may exceed 0.2 mm. Further, the resin sheet 7 is not an essential constituent member of the input sheet member 2 and may not be provided.

  The elastic body 8 as a filler is laminated on the back side of the resin sheet 7. Further, the elastic body 8 is filled in a recess formed at a position corresponding to the through hole 5 by the resin sheet 7. Since the resin sheet 7 is disposed so as to wrap around the elastic body 8 in the through hole 5, the elastic body 8 is not exposed to the operation surface side of the key sheet 3. The elastic body 8 is made of a flexible elastic material so that a switch member (not shown) or the like provided below the key 3a, 3b, 3c or the like can be pushed when the key 3a, 3b, 3c or the like is pressed from the front side. Preferably it is configured. Examples of the material for the elastic body 8 include thermosetting elastomers such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, and styrene butadiene rubber, urethane, ester, Styrene-based, olefin-based, butadiene-based, fluorine-based thermoplastic elastomers, or composites thereof can be used. Among these materials, it is preferable to use urethane-based elastomer, silicone rubber, or a composite material having high durability.

  The sealing layer 9 has a role of filling a gap generated between the inner surface of the through hole 5 and the resin sheet 7. When the sealing layer 9 is composed of a flexible resin layer, the sealing layer 9 includes the resin sheet 7 protruding into the through hole 5 by the filling pressure of the elastic body 8 and the inner surface of the through hole 5. It can be transformed into the gap between the two and filled. Further, the sealing layer 9 is preferably composed of a member that can adhere to the resin sheet 7 and the key sheet 3. As such a material of the sealing layer 9, for example, acrylic, urethane, ester, epoxy, vinyl chloride, acrylic or silicone ink can be suitably used. This resin can be particularly preferably used from the viewpoint of weather resistance, moisture resistance, heat resistance, and the like. The sealing layer 9 is suitably formed by screen printing or other printing techniques. Further, when a light-transmitting resin is used for the resin sheet 7, the elastic body 8, and the sealing layer 9, the light is transmitted through the inside of the through hole 5 when illuminated from the back side of the key sheet 3. The shape of characters and the like can be easily seen even in places.

  By configuring the input sheet member 2 from the components as described above, a gap is hardly generated between the inner surface of the through hole 5 and the resin sheet 7 on the operation surface side of the key sheet 3. This is because even if there is a gap between the inner surface of the through hole 5 and the resin sheet 7, the sealing layer 9 enters the gap and seals the through hole 5. Further, the sealing layer 9 is provided so that the depth of the gap formed on the inner side surface of the through hole 5 is 0.02 mm or less, more preferably 0.01 mm or less. The sealing layer 9 is provided so that the width of the gap formed on the inner surface of the through hole 5 is 0.02 mm or less. More preferably, at least a part of the sealing layer 9 on the operation surface side is formed to be flush with the operation surface side of the key sheet 3. In such a case, it is difficult for dirt to accumulate in the input sheet member 2. Moreover, since a user's nail | claw etc. are rarely caught in the through-hole 5, the user can operate more smoothly.

(Method for manufacturing input sheet member)
Next, the manufacturing method of the member 2 for input sheets is demonstrated.

  FIG. 4 is a flowchart showing a schematic flow of manufacturing the input sheet member 2. FIG. 5 is a view showing a state in which the input sheet member 2 in each step has the operation surface side facing the lower side of the drawing, and is a cross-sectional view similar to the region indicated by B in FIG. 3.

  First, as shown in FIG. 5A, the through hole 5 is provided in the key sheet 3 (step S101). The through hole 5 can be provided in the key sheet 3 by laser processing, etching, punching, or the like. When the through hole 5 is provided, it can be formed from the front side, the back side or both sides of the key sheet 3.

  Next, as shown in FIG. 5B, the film 10 is attached to the surface of the key sheet 3 (downward in FIG. 5) (step S102). The film 10 serves to protect the surface of the key sheet 3 and to fix the keys 3a, 3b, 3c and the like so as not to be displaced from predetermined positions. Furthermore, the film 10 has a so-called masking function of closing the through-hole 5 so that the sealing layer 9 does not leak to the surface of the key sheet 3 when forming the sealing layer 9 (described later). Therefore, the film 10 may be anything as long as it can be attached to the surface of the key sheet 3, and in particular, a PET sheet with an adhesive can be suitably used.

  Next, as shown in FIG. 5C, a sealing layer 9 is formed in the through hole 5 from the back side of the key sheet 3 (upper side of the paper in FIG. 5) (step S103: sealing layer). Forming step). Specifically, it is preferable that the material of the sealing layer 9 is formed inside the through-hole 5 on the back surface of the film 10 by printing and then dried. The sealing layer 9 may be formed inside the through-hole 5 by a method other than printing. However, the sealing layer 9 has a thickness that does not stand out from the appearance, and matches the position and shape of the through-hole 5. In order to form the sealing layer 9, it is preferable to form the sealing layer 9 by printing.

  Next, as shown in FIG. 5D, the resin sheet 7 is disposed on the back side of the key sheet 3 (upper side of the paper surface in FIG. 5) (step S104).

  Next, as shown in FIG. 5E, the elastic body 8 is disposed on the back side of the resin sheet 7, and the elastic body 8 is filled by integral molding (step S105: filling step). The elastic body 8 is pushed into the through-hole 5 while stretching the resin sheet 7 by the molding pressure. Finally, the film 10 is peeled off from the key sheet 3 to complete the input sheet member 2.

  By manufacturing the input sheet member 2 by the method as described above, when viewed from the operation surface side of the key sheet 3, a gap is hardly generated between the inner surface of the through hole 5 and the resin sheet 7. The resin sheet 7 and the elastic body 8 pushed in by the molding pressure can extend the sealing layer 9 into the gap between the resin sheet 7 and the through hole 5. Moreover, the input sheet member 2 can be manufactured by a simple process by forming the input sheet member 2 by integral molding.

  The input sheet member 2 and the manufacturing method thereof according to the present invention have been described above, but the present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

  For example, in the above-described embodiment, a layer such as an adhesive layer or a binder layer may be provided on the back surface of the resin sheet 7. In such a case, the adhesion or adhesive force between the resin sheet 7 and the elastic body 8 can be further improved.

  In the above-described embodiment, the sealing layer 9 is provided on the entire operation surface side of the opening of the through hole 5, but is not limited to such a form. The sealing layer 9 may be provided only in part of the opening of the through hole 5. In such a case, the sealing layer 9 is preferably provided so as to be in contact with the inner wall of the through-hole 5 where a gap is easily formed, and is covered with the operation surface side of the sealing layer 9 and the sealing layer 9. More preferably, at least one of the operation surfaces of the non-resin sheet 7 is flush with the operation surface of the key sheet 3. Moreover, although the sealing layer 9 is provided only in the opening part of the through-hole 5, it is not restricted to such a form. Further, the key sheet 3 may be provided with only one through hole 5 or a plurality of through holes 5.

  FIG. 6 is a cross-sectional view of the input sheet member 20 according to the modification of the present embodiment as viewed only in the region indicated by B in FIG.

  In the input sheet member 20, the sealing layer 29 extends not only from the surface side opening of the through hole 5 but also from the inner surface of the through hole 5 to the operation surface side, and covers the surface side opening of the through hole 5. Is formed. By configuring the input sheet member 20 as shown in FIG. 6, a gap is hardly generated between the inner surface of the through hole 5 and the resin sheet 7 on the operation surface side of the key sheet 3. Since the sealing layer 29 is also formed on the inner surface of the through hole 5, the sealing layer 9 is deformed by the resin sheet 7 and the elastic body 8 pushed into the through hole 5 by the molding pressure.

  FIG. 7 is a cross-sectional view of the input sheet member 30 according to a modification of the present embodiment as viewed only in the region indicated by B in FIG.

  In the above-described embodiment, the resin sheet 7 does not protrude from the surface of the key sheet 3, but is not limited to such a form. As shown in FIG. 7, the resin sheet 7 may have a shape protruding from the surface of the key sheet 3. Even in such a case, the sealing layer 9 can enter the gap between the resin sheet 7 and the inner surface of the through hole 5 in the same manner as described above.

  In the above-described embodiment, the elastic body 8 is formed so as to overflow from the through hole 5. Specifically, the elastic body 8 is laminated not only on the inside of the through hole 5 but also on the back surface side of the key sheet 3. However, it is not limited to such a form. The elastic body 8 does not need to be stacked on the back surface side of the key sheet 3 so that the elastic body 8 does not overflow from the through hole 5, that is, the elastic body 8 is filled only in the through hole 5.

  Moreover, in the above-mentioned embodiment, the through hole 5 is the through hole 5 having the same opening area on the front surface side and the back surface side and the same width from the front surface side to the back surface side. It is not limited to such a form. The through hole 5 may not have the same width from the front surface side to the back surface side. Moreover, the through-hole 5 does not need to have the same opening area on the front surface side and the back surface side.

  FIG. 8 is a diagram illustrating a state in which the operation surface side is directed to the lower side in the drawing in each step of the manufacturing process of the input sheet member 40 according to the modification of the present embodiment, and is a region indicated by B in FIG. 3. FIG.

  In the above-described embodiment and its modifications, the input sheet members 2, 20, and 30 are planar members, but are not limited to such a form. As shown in FIG. 8D, the input sheet member 40 has a curved surface shape, and may have a so-called three-dimensional shape.

  The input sheet member 40 is produced, for example, as follows. As shown in FIG. 8A, until the film 10 is pasted on the surface of the key sheet 3 provided with the through holes 5 and the sealing layer 9 is formed inside the through holes 5, the input sheet member is used. This is the same as steps S101 to S103 in the manufacturing method 2. Next, as shown in FIG. 8B, the key sheet 3 provided with the film 10 and the sealing layer 9 is bent into a curved shape so as to be convex on the front side. Next, as shown in FIG. 8C, the resin sheet 7 and the elastic body 8 are arranged on the back side of the key sheet 3 (upward in the drawing in FIG. 8), and integral molding is performed. As shown in FIG. 8D, the elastic body 8 is pushed into the through hole 5 while the resin sheet 7 is stretched by the molding pressure. Finally, the film 10 is peeled off from the key sheet 3 to complete the input sheet member 40.

  When bending is performed like the input sheet member 40, the gap between the resin sheet 7 and the inner surface of the through hole 5 tends to increase. However, by providing the sealing layer 9 on the input sheet member 40, the width and depth of the gap between the resin sheet 7 and the inner surface of the through hole 5 can also be reduced.

  Next, examples of the present invention will be described.

  In this example, the depth of the gap between the inner surface of the through hole and the resin sheet was measured using each test piece.

(Test piece preparation method)
As a key sheet, a flat plate made of SUS304 and having a thickness of 0.15 mm was used. First, a through hole having each width was provided in the key sheet. Next, screen printing using urethane-based two-component curable ink (product number: HAC, manufactured by Seiko Advance Co., Ltd.) is performed from the back side of the key sheet, thereby sealing the entire surface of the key sheet including the through hole portion. A layer was provided. Next, a polyurethane film (product number: DUS605, manufactured by Sea Dam Co., Ltd.) was disposed as a resin sheet on the back side of each key sheet. Furthermore, the member for input sheets which concerns on each Example was obtained by arrange | positioning silicone resin as a filler on the back surface side of the resin sheet, and performing integral molding.

(Evaluation methods)
The uneven state of the surface of the input sheet member according to each example was examined by scanning a non-contact three-dimensional measuring device (trade name: NH-3N, Mitaka Koki Co., Ltd.). In addition, the result is overlapped with the position of the through hole, and the width of the gap formed between the inner surface of the through hole and the resin sheet (distance when the opening of the gap is measured along the width direction of the through hole) The depth of the through hole (the distance from the key sheet surface to the deepest part of the gap) was measured. The measurement was performed on 100 test pieces, and the average value was used as the evaluation result.

  Next, evaluation results in each example will be described. Table 1 summarizes the evaluation results.

Example 1
An input sheet member having a through hole width (in the case of the through hole 5 of 3a in FIG. 3, the distance in the left-right direction in FIG. 3) of 0.5 mm was manufactured. In the input sheet member of Example 1, the width of the gap between the inner surface of the through hole and the resin sheet was extremely narrow, 0.005 to 0.012 mm. Moreover, in the member for input sheets of Example 1, the depth of the clearance gap between the inner surface of a through-hole and a resin sheet was also very small, and was 0.003-0.008 mm.

(Example 2)
An input sheet member having a through hole width of 0.3 mm was manufactured. In the input sheet member of Example 2, the width of the gap between the inner surface of the through hole and the resin sheet was extremely narrow, 0.005 to 0.015 mm. Moreover, in the member for input sheets of Example 2, the depth of the clearance gap between the inner surface of a through-hole and a resin sheet was also very small, and was 0.004-0.013 mm.

(Comparative Examples 1-2)
The same thing as said each Example was manufactured except not having provided the sealing layer. Although each comparative example is a member for an input sheet that can withstand practical use, since the sealing layer is not provided, the width of the gap between the inner surface of the through hole and the resin sheet on each surface of the key sheet It was bigger than the example. In each comparative example, the depth of the gap between the inner surface of the through hole and the resin sheet was also larger than in each example.

  The present invention can be used for, for example, a push button switch as an input device of various electronic devices.

2, 20, 30, 40 Input sheet member 3 Key sheet (key assembly board)
3a, 3b, 3c Key 5 Through-hole 7 Resin sheet 8 Elastic body (filler)
9,29 Sealing layer

Claims (5)

A key or key assembly plate having one or more through holes penetrating in the front and back direction;
A filler filled into the through hole from the back surface of the key or the key assembly plate;
A sealing layer that seals at least a gap between the through hole and the filler inside the through hole;
An input sheet member comprising: The input sheet member according to claim 1,
The input sheet member, wherein the sealing layer is formed so as to extend from an inner surface of the through hole to an operation surface side. The input sheet member according to claim 1 or 2,
The sealing layer is provided so that the depth of the gap with the inner surface of the through hole is 0.02 mm or less and the width of the gap is 0.02 mm or less. Sheet member. The input sheet member according to any one of claims 1 to 3,
The input sheet member, wherein the sealing layer is a printed layer formed by printing. A method for manufacturing a member for an input sheet comprising a key or a key assembly plate having one or more through holes penetrating in the front-back direction,
A sealing layer forming step of forming a sealing layer in the through-hole portion;
A filling step of filling a filling material filled in the through hole from the back surface of the key or the key assembly plate;
The manufacturing method of the member for input sheets characterized by including these.

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