JP5427639B2 - Switch module - Google Patents

Description

  The present invention relates to a switch module provided to face a key substrate of an electronic device such as a mobile phone or a notebook PC.

  2. Description of the Related Art Conventionally, electronic devices such as mobile phones and notebook PCs are provided with a key board having a key portion, and a switch module that switches ON / OFF of the electrical connection by contact or non-contact of the key top is provided on the key board. Opposed. FIG. 5 shows a schematic cross-sectional view of a conventional switch module 100 arranged to face a key substrate 80 having a key portion 70.

  As shown in FIG. 5, the switch module 100 is provided with a metal dome 50 that encloses the electrode 55, a circuit board 60, a light guide member 30, and an LED (Light Emitting Diode) 20 as a light emitting element. The metal dome 50 is integrally held on the circuit board 60 by the metal dome sheet 40, and the light guide member 30 is attached to the metal dome sheet 40 at a predetermined interval by an adhesive layer 35. The light guide member 30 is provided with a light scattering processing portion 30a such as a printing process in which white ink is printed in the form of dots or a prism process on the lower surface of the light guide member 30, and between the light guide member 30 and the LED 20. A reflector (reflective member) 25 for efficiently guiding light emitted from the LED 20 from the end of the light guide member 30 into the light guide member 30 is provided.

  According to such a configuration, the switch can be turned on and off by electrical contact or non-contact between the metal dome 50 and the electrode 55 due to the key portion 70 being pressed downward and the metal dome 50 being deformed. Since the light guide member 30 is provided on the back surface of the key substrate 80, that is, between the key substrate 80 and the metal dome sheet 40, the light emitted from the LED 20 and entering the light guide member 30 is reduced. Each key portion 70 can be illuminated from within the light guide member 30 by being scattered by the light scattering processing portion 30a. Related techniques are disclosed in Patent Documents 1 to 6.

JP 2009-246821 A JP 2008-15951 A JP 2009-140871 A JP 2009-187855 A Japanese Patent Laid-Open No. 2004-139983 JP 2008-226844 A

  However, the conventional configuration has the following problems.

  FIG. 5B schematically shows the traveling direction of light in the light guide member 30. Light emitted from the LED 20 and incident into the light guide member 30 from the end of the light guide member 30 by the reflector 25 is repeatedly reflected on the upper and lower surfaces of the light guide member 30, for example, as indicated by L <b> 1 in the drawing. However, the light guide member 30 is advanced. Further, like the light indicated by L2 in the drawing, there is also light scattered by the light scattering processing portion 30a so as to escape from the upper surface of the light guide member 30 in the direction of the key portion 70 (by the light thus scattered. The key unit 70 is illuminated).

  However, the light entering the light guide member 30 is leaked in the direction of the key substrate 80 from the adhesive layer 35 when the adhesive layer 35 is on the optical path, as indicated by L3 in the drawing. Exists. More specifically, light enters the metal dome sheet 40 through the adhesive layer 35 from the light guide member 30, and the light transmitted through the adhesive layer 35 again by reflection on the surface of the metal dome 50 or the like is reflected on the key substrate 80. Will leak in the direction. As a result, when the key substrate 80 is viewed from the top surface (from the normal direction of the key substrate 80 and the light guide member 30), the portion where the L3 light leaks, that is, the portion where the adhesive layer 35 is provided is the other portion. Compared with the area of, there is a phenomenon that it is extremely bright.

  FIG. 6A shows a top view of the conventional switch module 100. As illustrated, the adhesive layer 35 is provided in the vicinity of the outer periphery of the light guide member 30. Moreover, the arrow in a figure has shown the optical path and the advancing direction of the light inject | emitted from LED20. However, in such a configuration, light leaks out at the portion where the adhesive layer 35 is provided as described above, and is emitted from the LED 20 particularly when the switch module 100 is viewed from the upper surface of the key substrate 80. More light leaks from the light guide member 30 at the portion where the optical path of light overlaps with the adhesive layer 35 and at the portion near the optical path of the light emitted from the LED 20.

  Here, in FIG. 6 (b), in the configuration of the switch module 100 shown in FIG. 6 (a), portions where light leakage from the adhesive layer 35 is particularly remarkable are indicated by hatched portions, and the respective regions are indicated by A, B, C. And In the area A, the light immediately after being emitted from the LED 20 leaks out, so that significant light leakage can be confirmed. In the region B, light that has entered from the end portion of the light guide member 30 and reached the other end leaks out, and the light is attenuated. A leak can be confirmed. Further, in the region C, since there is a corner portion of the light guide member 3, there is much light leakage, and particularly in the region close to the LED 20 (the upper region C in the figure), significant light leakage can be confirmed.

  On the other hand, as indicated by a dotted line in the figure, an illumination area is set in advance in the light guide member 30. The illumination area is an area corresponding to each key portion 70 provided on the key substrate 80, and light is intentionally scattered in the direction of the key portion 70 from the area, thereby corresponding key portions. 70 can be suitably illuminated. However, as described above, the light emitted from the LED 20 into the light guide member 30 leaks out at the portion where the adhesive layer 35 is provided, and the leakage amount is particularly significant in the illustrated regions A, B, and C.

  Therefore, at the position where the area where the light from the adhesive layer 35 leaks and the illumination area overlap, or when both areas are close to each other, not only the light transmitted from the illumination area but also the light leaking from the adhesive layer 35 causes the key portion 70. Therefore, there is a problem that such a key part 70 is remarkably excessively lit compared to other key parts 70. Further, in order to avoid this problem, for example, a method of moving the illumination area away from the illustrated areas A, B, and C is conceivable. However, in this case, a new design restriction may occur due to the design of the key portion arrangement. There is a problem.

  That is, in the conventional configuration, in the switch module 100 in which the adhesive layer 35 is provided on the outer periphery of the light guide member 30 or in the vicinity of the outer periphery, when the gap between the adhesive layer 35 and the illumination area is narrowed, It cannot suppress that a certain key part 70 shines too much.

  Therefore, the present invention provides a switch module in which an adhesive layer is provided on the outer periphery of the light guide member or in the vicinity of the outer periphery, while the key portion near the adhesive layer is different from the other key portions while narrowing the interval between the adhesive layer and the illumination area. An object of the present invention is to provide a switch module that can suppress excessive light emission.

In order to achieve the above object, the present invention provides:
A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer The switch module is characterized in that a notch is formed at a predetermined position.

  According to such a configuration, when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer has a cutout portion at a predetermined position, so in the portion where the cutout portion is formed, Light leakage from the adhesive layer can be reduced. Therefore, even if the interval between the adhesive layer and the illumination area is narrowed, it is possible to prevent the key portion in the vicinity of the adhesive layer from being excessively illuminated as compared with other key portions.

In order to achieve the above object, in the present invention,
A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer Is provided with a portion where the width of the adhesive layer becomes narrow at a predetermined position.

  According to such a configuration, when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer is provided with a portion where the width of the adhesive layer becomes narrow at a predetermined position. In this portion, light leakage from the adhesive layer can be reduced. Therefore, even if the interval between the adhesive layer and the illumination area is narrowed, it is possible to prevent the key portion in the vicinity of the adhesive layer from being excessively illuminated as compared with other key portions.

In order to achieve the above object, in the present invention,
A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer Is provided with a notch portion and a portion where the width of the adhesive layer becomes narrow at a predetermined position.

  According to such a configuration, when the light guide member is viewed from the normal direction of the key substrate, the notch portion and the portion where the width of the adhesive layer becomes narrow are provided at predetermined positions of the adhesive layer. Leakage of light from the adhesive layer in this portion can be reduced. Therefore, even if the interval between the adhesive layer and the illumination area is narrowed, it is possible to prevent the key portion in the vicinity of the adhesive layer from being excessively illuminated as compared with other key portions.

In addition, the predetermined position is
When the light guide member is viewed from the normal direction of the key substrate,
It is preferable that at least one of a position where the optical path of the light traveling in the light guide member and the adhesive layer overlap, or a position near the optical path of the light traveling in the light guide member.

  According to this configuration, when the light guide member is viewed from the normal direction of the key substrate, the position where the optical path of the light traveling in the light guide member and the adhesive layer overlap, or the vicinity of the optical path of the light traveling in the light guide member Since at least one of the positions is provided with a notch and a portion where the width of the adhesive layer becomes narrow, it is possible to more effectively reduce light leakage from the adhesive layer at these portions. .

  As described above, according to the present invention, in the switch module in which the adhesive layer is provided on the outer periphery of the light guide member or in the vicinity of the outer periphery, the key in the vicinity of the adhesive layer while reducing the distance between the adhesive layer and the illumination area. It is possible to provide a switch module capable of suppressing the portion from being excessively lighted compared to other key portions.

1 is a schematic cross-sectional view of a switch module according to an embodiment of the present invention. The top view of the switch module concerning the embodiment of the present invention. The top view of the switch module concerning the embodiment of the present invention. The top view of the switch module concerning the embodiment of the present invention. The schematic sectional drawing of the conventional switch module. The top view of the conventional switch module.

  DETAILED DESCRIPTION Exemplary embodiments for carrying out the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

[Embodiment]
<1: Overall configuration of switch module>
With reference to Fig.1 (a), the whole structure of the switch module 1 which concerns on embodiment which can apply this invention is demonstrated. FIG. 1A is a schematic cross-sectional view of the switch module 1 according to the present embodiment.

  The switch module 1 according to the present embodiment is disposed to face a key substrate 8 having a key portion 7, and can be used for, for example, a 10-key substrate and a QWERTY key substrate in an electronic device such as a mobile phone and a notebook PC. is there. It can also be used for a touch panel or the like.

  As shown in FIG. 1A, the switch module 1 includes an LED 2 as a light emitting element, a circuit board 6 having an electrode 11 (an FPC board (Flexible Printed Circuit) is applicable), and a metal dome 5 that covers each electrode 11. A metal dome sheet 4 (electrode layer) having a light guide, and a light guide sheet 3 (light guide member) attached on the metal dome sheet 4 by an adhesive layer 10. The adhesive layer 10 may be formed by laminating a sheet-like adhesive, or may be formed by a dispenser or screen printing. Further, between the LED 2 and the light guide sheet 3, there is provided a reflector 9 (reflecting member) that allows light emitted from the LED 2 to enter the light guide sheet 3 efficiently from the end of the LED 2. The end of the reflector 9 extends to a position that covers the upper surface of the end of the light sheet 3.

  According to this configuration, the key top 7a moves downward in the drawing to press the metal dome sheet 4, thereby deforming the metal dome 5 and bringing the metal dome 5 and the electrode 11 into contact with each other. The electrode 11 is electrically connected, that is, the switch is switched from OFF to ON. In general, it is desirable for the switch module to transmit a sufficient click feeling to the user when the key unit is pressed from the viewpoint of operability. However, according to the present embodiment, the switch module has a certain strength. Since the switch is switched between ON and OFF by deformation of the metal dome 5 having the above, a sufficient click feeling can be transmitted to the user.

  Each metal dome 5 is integrally bonded to the metal dome sheet 4, and in the manufacturing process, the metal dome sheet 4 on which the metal dome 5 has been mounted is attached to the circuit board 6, so that the plurality of electrodes 11 are attached. On the other hand, the metal dome 5 can be attached with high accuracy and in a simple process. In this embodiment, a transparent adhesive sheet having a thickness of 50 μm is used as the metal dome sheet 4.

<2: About the light guide sheet>
The light guide sheet 3 used in this embodiment will be described. In this embodiment, a urethane rubber sheet (thermosetting) having a thickness of 125 μm and a Shore hardness of 97 is used, but the material applicable as the light guide sheet 3 is not limited to this, A transparent sheet such as a polycarbonate film or a silicone rubber sheet may be used. Moreover, although the thickness of the light guide sheet 3 is not particularly limited, it can be said that the thickness is preferably 100 μm or more and 300 μm or less. The “transparent sheet” here does not necessarily mean colorless and transparent, and the light guide sheet 3 is limited to “colorless and transparent” as long as the light emitted from the LED 2 can be transmitted. is not.

  In the present embodiment, since the light guide sheet 3 having such a small thickness is used, the switch module 1 can be reduced in size and the click sensitivity described above can be further improved. In the following, on the surface of the light guide sheet 3, the surface facing the key substrate 8 (upper surface in the drawing) is referred to as “first surface 3 b”, and the surface facing the circuit substrate 6 (lower surface in the drawing). Is described as “second surface 3c”.

  The light guide sheet 3 is subjected to light scattering processing on the second surface 3c so that light incident on the light guide sheet 3 is scattered and the key portion 7 can be illuminated from within the light guide sheet 3 by the scattered light. Yes. Here, as light scattering processing, dot printing (printing processing) with white ink (ink having light scattering properties) is performed by an ink jet printer, thereby printing white dots 3a on the second surface 3c. More specifically, a white UV curable ink A (main agent: photopolymerizable composition 70 to 90% by mass, pigment: titanium dioxide 10 to 20% by mass, other: polymerization initiator 5% by mass or less) is used as a piezo as an inkjet head. The formula (360 dpi, droplet amount: 14 pl) was employed, and printing was performed using Subzero (manufactured by Integration) as a UV curing device. In this embodiment, white ink is used, but ink having a light scattering property may be used.

  The white dots 3 a are printed at positions corresponding to the key portions 7, whereby the light incident on the light guide sheet 3 from the LEDs 2 is scattered by the white dots 3 a, and the light guide sheet is scattered by the scattered light. It is possible to illuminate the key portion 7 from within 3. The dot density, shape, and the like of the white dots 3a are not particularly limited. For example, by increasing the number of white dots 3a in a region away from the LED 2 (region where light is attenuated and transmitted), Even the key portion 7 arranged in a region away from the LED 2 can be illuminated with a sufficient amount of light.

  In addition, the form of light scattering processing is not limited to this, and is a form in which three-dimensional shape processing by mold processing, laser processing, or the like is performed at a predetermined position, and the light guide sheet 3 is formed with uneven shapes and prism shapes. There may be. Also in this case, similarly to the white dots 3a, it is possible to illuminate the key portion 7 suitably by scattering light by the portion subjected to the three-dimensional shape processing. The printing process (white dots 3a) is performed on the second surface 3c, but the three-dimensional shape process may be performed on the first surface 3b of the light guide sheet 3. Also in this case, the light is scattered in the three-dimensional shape processing applied to the first surface 3b, so that the light is transmitted from the first surface 3b in the direction of the key portion 7, and the key portion 7 is suitably illuminated. It becomes possible.

<3: About the reflector>
In this embodiment, the reflector 9 for making the light inject | emitted from LED2 inject into the light guide sheet 3 efficiently from the edge part of the light guide sheet 3 is provided. When the light guide sheet 3 having a small thickness is used as in the present embodiment, the thickness of the light guide sheet 3 is often thinner than the light emission area width of the LED 2. In order to make the light emitted from the LED 2 enter the light guide sheet 3 efficiently, it is effective to provide the reflector 9 between the LED 2 and the light guide sheet 3. In the present embodiment, the reflector 9 is provided at the end of the light guide sheet 3 so as to cover the first surface 3b in order to make light incident more efficiently, but the shape of the reflector 9 is particularly limited. It is not something. Moreover, as shown in the figure, a predetermined interval may be provided between the reflector 9 and the first surface 3b, or the reflector 9 and the first surface 3b may be brought into close contact with each other without providing an interval.

<4: How the light travels>
FIG. 1B schematically shows a light traveling pattern in the light guide sheet 3. The light emitted from the LED 2 is incident on the light guide sheet 3 from the end of the light guide sheet 3 by the reflector 9 (some light is directly incident on the light guide sheet 3 without going through the reflector 9). In the present embodiment, the first surface 3b and the second surface 3c of the light guide sheet 3 are both in contact with the air layer, and the difference in refractive index (assuming that the refractive index of the air layer is 1.0) Since the refractive index of the sheet 3 is about 1.45), the light traveling in the light guide sheet 3 repeats reflection on the first surface 3b and the second surface 3c, while the other of the light guide sheet 3 is reflected. It will proceed toward the end (L1 in the figure). Further, when there is a white dot 3a on the optical path, light is scattered at the white dot 3a, and the light exits from the inside of the light guide sheet 3 toward the key portion 7 (L2 in the figure).

<5: Configuration for reducing light leakage>
With reference to FIG.1 (b), the structure which reduces "the leakage of the light from the part in which the contact bonding layer is provided" mentioned as the conventional subject is demonstrated.

  As described above, in the conventional configuration, the light emitted from the LED is scattered and refracted by the adhesive layer. The light that has passed through the light guide sheet is reflected by the surface of the metal dome, etc., and is scattered and refracted again by the adhesive layer, causing a problem of “too much light” in the key portion. Therefore, in this embodiment, in order to solve this problem, as shown in FIG. 1B, by providing a notch portion 10a at a predetermined position of the adhesive layer 10, leakage of light from the adhesive layer 10 is reduced. It is characterized in that “too much light” of the key portion 7 is suppressed. In addition, although there exists a concern about the fall of the adhesive force of the light guide sheet 3 and the metal dome sheet 4 by providing the notch part 10a, even if the notch part 10a is provided, the light guide sheet 3 and the metal dome sheet It is assumed that the allowable level of the adhesive strength with 4 is sufficiently maintained.

<6: Position where the notch is provided>
In the present embodiment, the adhesive layer 10 is provided near the outer periphery of the light guide sheet 3 (the adhesive layer 10 may be provided on the outer periphery of the light guide sheet 3). The position where the above-described notch portion 10a is provided is not particularly limited, and it is possible to suppress “excessive light” of the key portion 7 in the vicinity of the notch portion 10a at any position. .

  However, it is more effective to provide the notch 10a in the vicinity of the key portion 7 where “too much light” is noticeable (in the case of FIG. 6B, in the vicinity of the region A, the region B, and the region C). For example, when the light guide sheet 3 is viewed from the upper surface of the key substrate 8 (when viewed from the normal direction of the key substrate 8 and the light guide sheet 3), the optical path of the light traveling in the light guide sheet 3 and the adhesive layer 10 When the notch portion 10a is provided at least one of the position where the two overlap each other or the position in the vicinity of the optical path of the light traveling in the light guide sheet 3, the “excessive light” of the key portion 7 is more effectively suppressed. Thus, the plurality of key portions 7 provided on the key substrate 8 can be illuminated almost uniformly. In the following, (Embodiment 1) to (Embodiment 6) will be described, which are particularly effective in suppressing “too much light” of the key portion 7.

Example 1
With reference to Fig.2 (a), the switch module which concerns on Example 1 is demonstrated. In Example 1, the notch 10a is provided on the side of the illumination area indicated by the oblique lines in the drawing. As shown by region C in FIG. 6B, the amount of light leakage is particularly large at the corners of the adhesive layer, and the key portion located in this region is extremely light compared to other key portions. There's a problem. On the other hand, by providing the notch portion 10a at the position shown in FIG. 2A, at least the “light” of the key portion 7 corresponding to the illumination area (and the illumination area located therearound) indicated by the oblique lines in the figure. "Excess" can be effectively suppressed.

(Example 2)
A switch module according to the second embodiment will be described with reference to FIG. In Example 2, in addition to the side of the illumination area indicated by hatching in the drawing, a notch 10a is provided on the front side (LED2 side). Also with this configuration, as in (Example 1), at least “excessive light” of the key portion 7 corresponding to the illumination area (and the illumination area located around the illumination area) indicated by hatching in the drawing is effectively suppressed. Can do. It should be noted that (Example 1) and (Example 2) showed almost no difference in the effect of suppressing excessive light of the key portion 7. That is, in the arrangement of the key portion 7 and the LED 2 in the present embodiment, it can be said that the effect of suppressing the excessive light emission of the key portion 7 is more effective when the cutout portion 10a is provided on the side (light path and side of the light). Since a certain adhesive layer 10 is almost overlapped, light leakage at the side greatly affects the “too much light” of the key part), while suppressing the “too much light” of the key part 7 while adhering to the light guide sheet 3. From the viewpoint of maintaining the force, it can be said that (Example 1) is preferable.

(Example 3)
With reference to FIG. 3A, a switch module according to the third embodiment will be described. In the third embodiment, a notch 10a is provided on the side of the illumination area indicated by oblique lines in the drawing. As shown by region C in FIG. 6B, the amount of light leakage is particularly large at the corners of the adhesive layer, and the key portion located in this region is extremely light compared to other key portions. There's a problem. On the other hand, by providing the notch 10a at the position shown in FIG. 3A, at least the “light” of the key portion 7 corresponding to the illumination area (and the illumination area located around it) indicated by the oblique lines in the figure. "Excess" can be effectively suppressed.

Example 4
With reference to FIG.3 (b), the switch module which concerns on Example 4 is demonstrated. In Example 4, the notch 10a is provided on the side of the illumination area indicated by oblique lines in the drawing. Although not particularly shown in FIG. 6B, the key portion near the side of the adhesive layer is located near the optical path of the light emitted from the LED, and thus there is a case where the key portion is “too bright”. . On the other hand, by providing the notch 10a at the position shown in FIG. 3B, the “light” of the key portion 7 corresponding to at least the illumination area (and the surrounding illumination area) indicated by the oblique lines in the figure. "Excess" can be effectively suppressed.

(Example 5)
With reference to Fig.4 (a), the switch module which concerns on Example 5 is demonstrated. In Example 5, the notch part 10a is provided in the front side (LED2 side) of the illumination area shown with the oblique line in the figure. As shown by the area A in FIG. 6B, in the adhesive layer, “too much light” of the key portion is seen in the area on the optical path of the light emitted from the LED. On the other hand, by providing the notch 10a at the position shown in FIG. 4A, at least the “light” of the key portion 7 corresponding to the illumination area (and the surrounding illumination area) indicated by the oblique lines in the figure. "Excess" can be effectively suppressed.

(Example 6)
With reference to FIG. 4B, a switch module according to the sixth embodiment will be described. In Example 6, the notch 10a is provided on the rear side (the side opposite to the LED 2) of the illumination area indicated by hatching in the drawing. As shown by a region B in FIG. 6B, in the region of the adhesive layer on the optical path of the light emitted from the LED, “too much light” of the key portion is observed. On the other hand, by providing the notch 10a at the position shown in FIG. 4B, the “light” of the key portion 7 corresponding to at least the illumination area (and the surrounding illumination area) indicated by the oblique lines in the figure. "Excess" can be effectively suppressed.

(Other examples)
The position where the notch 10a is provided is not limited to the above (Example 1) to (Example 6). The position where the notch 10a is provided may be appropriately changed according to the arrangement of the illumination area, the LED, and the like. Moreover, it is also possible to combine the configurations described in (Example 1) to (Example 6). In (Example 1) to (Example 6), there is an optical path of light emitted from the LED 2 between each illumination area, but the arrangement relationship between each illumination area and the LED 2 is limited to this. Instead, it is possible to obtain the same effect as described above by providing the adhesive layer 10 with the notch 10a regardless of the arrangement relationship.

Further, the length of the notch 10a can be changed as appropriate. For example, in the case of the configuration in which (Example 5) and (Example 6) are combined, the lower side (the side farther from the LED 2) than the length of the notch 10a provided on the upper side (the side closer to the LED 2). It is preferable to shorten the length of the notch portion 10b provided in (). That is, although “too much light” appears remarkably in the key portion 7 located near the LED 2, light is attenuated in the key portion 7 located far from the LED 2, so that the former key portion 7. The level of “too bright” is lower than that. Therefore, the amount of light leakage from the adhesive layer 10 and the light condition of the key portion 7 may be adjusted by adjusting the length of the notch 10a.

<7: Configuration other than the notch>
In the present embodiment, the configuration for suppressing the “over-light” of the key portion 7 by providing the notch portion 10 a in the adhesive layer 10 has been described. However, the configuration for suppressing the “over-light” of the key portion 7 is described here. It is not limited. For example, the notch portion 10a is not provided, and the width of the adhesive layer 10 (the width when viewed from the top surface of the key substrate 8 and the light guide sheet 3) may be narrowed. The position where the width of the adhesive layer 10 is narrowed may be the same as the “position where the notch portion 10a is provided” described in (Example 1) to (Example 6) and (Other Examples).

  According to such a configuration, in the portion where the width of the adhesive layer 10 is narrow, the amount of light leaking from the adhesive layer 10 can be reduced as compared with other portions. Can be effectively suppressed. Moreover, compared with the structure which provides the notch part 10a, there also exists an effect that it becomes easy to maintain the adhesive force of the light guide sheet 3 and the metal dome sheet | seat 4. FIG. In addition, the structure which provides both the notch part 10a and the part to which a width | variety becomes narrow with respect to the contact bonding layer 10 may be sufficient.

  Further, when the adhesive layer 10 is printed in a dot shape, the configuration may be such that the light density in the adhesive layer 10 is adjusted by controlling the dot density. Even in this case, the same effect as described above can be obtained.

<8: Effects of the present embodiment>
According to the switch module 1 according to the present embodiment, the following effects that cannot be obtained with the conventional configuration can be obtained.

(Restrictions on design of key part layout)
According to the switch module 1 according to the present embodiment, since the amount of light leakage from the adhesive layer 10 can be reduced by the above-described configuration, even if the interval between the adhesive layer 10 and the illumination area is narrowed, the switch module 1 is in the vicinity of the adhesive layer 10. “Excessive light” of the key portion 7 can be suppressed. Therefore, in the conventional configuration, the problem of “excessive light” has occurred in the key portion near the adhesive layer. However, according to the present embodiment, the distance between the illumination area of the key portion 7 and the adhesive layer 10 is reduced. However, since the key portion 7 can be prevented from being “excessively light”, the plurality of key portions 7 provided on the key substrate 8 can be illuminated almost uniformly and the degree of freedom in design can be increased in designing the arrangement of the key portion 7. (The key portion 7 can be arranged up to a position corresponding to the vicinity of the edge of the light guide sheet 3).

  As described above, according to the present embodiment, in the switch module in which the adhesive layer is provided on the outer periphery of the light guide member or in the vicinity of the outer periphery, the key portion in the vicinity of the adhesive layer is reduced while reducing the distance between the adhesive layer and the illumination area. It is possible to provide a switch module that can suppress excessive light compared to other key portions.

  DESCRIPTION OF SYMBOLS 1 ... Switch module 2 ... LED 3 ... Light guide sheet 3a ... White dot 3b ... 1st surface 3c ... 2nd surface 4 ... Metal dome sheet 5 ... Metal dome 6 ... Circuit board 7 ... Key part 8 ... Key board 9 ... Reflector 10 ... Adhesive layer 10a ... Notch 11 ... Electrode

Claims (4)

A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer The switch module is characterized in that a notch is formed at a predetermined position. A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer The switch module is characterized in that a portion where the width of the adhesive layer becomes narrow is provided at a predetermined position. A switch module provided opposite to a key board having a key part,
A circuit board having an electrode layer formed on a surface facing the key board;
A light guide member provided between the key board and the circuit board;
A light source element that emits light;
A reflection member that causes light emitted from the light source element to enter the light guide member from an end of the light guide member;
With
A switch that can be turned on and off by moving the key portion with respect to the electrode layer, and that can illuminate the key portion from within the light guide member by light incident on the light guide member. In the module
The light guide member is adhered to the electrode layer via an adhesive layer at the outer periphery or in the vicinity of the outer periphery, and when the light guide member is viewed from the normal direction of the key substrate, the adhesive layer The switch module is characterized in that a notch portion and a portion where the width of the adhesive layer becomes narrow are provided at predetermined positions. The predetermined position is
When the light guide member is viewed from the normal direction of the key substrate,
The optical path of the light traveling in the light guide member and the adhesive layer are at least one of a position where the light path and the adhesive layer overlap each other, or a position in the vicinity of the optical path of the light traveling in the light guide member. The switch module according to any one of the above.

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