JP2008226613A - Illumination sheet and operation switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination sheet that emits stronger light from emitting-surface regions for a long period of time, while preventing emission of lights at parts other than the emitting-surface regions. <P>SOLUTION: The illumination sheet 10 is configured to emit light, which is emitted from a light source 13 and guided through the inside of a sheet-like material, from each emitting-surface region 15 provided on its surface. The illumination sheet is provided with a sheet-like core layer 21, whose surface is formed into a mirror surface, and a clad layer 23 that covers the surface of the core layer 21. The illumination sheet is configured so that light is guided inside the core layer 21, while being reflected by the clad layer 23. The clad layer 23 has an opening part 25 in the emitting-surface region 15. The surface of the core layer 15 is exposed at the opening part 25, while the surface of the exposed core layer 21 is roughened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illumination sheet configured such that light from a light source is guided through a sheet-like interior and emitted from a predetermined position, and an operation switch using the illumination sheet.

  In recent years, illumination sheets configured such that light from a light source is guided through a sheet-like interior and emitted at a predetermined position have been proposed in various fields.

  For example, Patent Document 1 below proposes a light guide plate used for a backlight or the like of a liquid crystal panel, which receives light from a light source on a side surface and uniformly emits light on the entire surface. Here, the light guide plate is formed of a flexible member, light scattering portions are provided at a plurality of positions of the light guide plate, and light guided along the light guide plate by the light scattering portions is emitted from the surface. I am doing so. In such a light guide plate, it is possible to increase the light emitted from the position of the light scattering portion if the light scattering portion is provided only at a specific position rather than the entire light guide plate.

Further, for example, Patent Document 2 below proposes a keypad that is fixed to the light guide plate and is provided with at least one reflection pattern for reflecting a part of the light spreading in the light guide plate to the surface side. ing. Here, since the reflection pattern is provided locally, it is possible to radiate light locally by the reflection pattern. In this patent document 2, it is made difficult to radiate | emit the light in a light-guide plate outside in parts other than a reflective pattern by making it totally reflect in a boundary with an external air layer.
JP 2004-200093 A JP 2006-323843 A

  However, in these illuminating sheets such as the light guide plate, in order to radiate light locally and not to radiate light sufficiently in other parts, the guided light is not diffusely reflected in the illuminating sheet. There is a need to. Therefore, in the said patent document 2, it is necessary to make the surface of a light-guide plate into a uniform mirror surface without an unevenness | corrugation. This is because if the surface is uneven, the incident angle of the light that travels while being reflected in the light guide plate changes at that portion, so that the total reflected condition is not satisfied and the emitted light increases.

  However, even when the surface of the illuminating sheet is formed into a mirror surface, if damage such as scratches occurs on the mirror surface during manufacture or use, the light guided at that portion is irregularly reflected, and the light is emitted outside a predetermined area. Was easy to radiate.

  Further, when the surface of the illumination sheet is made into a mirror surface, dust and the like are easily attached, and light guided in the illumination sheet is easily diffusely reflected by the attached dust. The amount of light emitted increased, and the light emitted from the predetermined radiation surface area was likely to become weaker over time.

  In view of this, an object of the present invention is to provide an illumination sheet capable of emitting stronger light from a predetermined radiation surface area while preventing light emission in a portion other than the predetermined area over a long period of time. It is another object to provide an operation switch using such an illumination sheet.

  The illuminating sheet according to claim 1, which solves the above problem, is a illuminating sheet in which light from a light source is guided through a sheet-like interior and radiated from a predetermined radiating surface area, the surface of which is formed into a mirror surface. A core layer having a shape and a cladding layer covering the surface of the core layer, wherein the light is guided in the core layer while being reflected by the cladding layer,

  The cladding layer has an opening in the radiation surface region, the surface of the core layer is exposed in the opening, and the exposed surface of the core layer is roughened. .

  In the illumination sheet according to claim 2, in addition to the configuration according to claim 1, the surface of the core layer is roughened on the inner side of the periphery of the opening and is mirror-finished on the outer side of the periphery of the opening. It is formed.

  The illumination sheet according to claim 3 is characterized in that a plurality of the radiation surface regions are provided in addition to the configuration according to claim 1 or 2.

  The illumination sheet according to claim 4 is characterized in that, in addition to the configuration according to any one of claims 1 to 3, the radiation surface area is a deformation part that is repeatedly deformed in a direction intersecting the surface. And

  The operation switch according to claim 5 is a lighting operation sheet according to any one of claims 1 to 4, wherein the operation switch is operated from the front surface side and the surface operation unit is disposed on the back side of the surface operation unit. And a light source for supplying light to the illuminating sheet, wherein the surface operation unit transmits light from the radiating surface area to a position corresponding to the radiating surface area of the illuminating sheet. And a translucent display portion configured to be visually recognized from the surface side.

  The operation switch according to claim 6 includes a surface operation portion that is pressed from the front surface side, a base portion that is spaced from and opposed to the surface operation portion, and between the surface operation portion and the base portion. An operation switch comprising the illumination sheet according to any one of claims 1 to 4 and a light source that supplies light to the illumination sheet, wherein the surface operation unit is formed on the illumination sheet. A light-transmitting display unit configured to transmit light from the radiation surface region and be visually recognized from the surface side at a position corresponding to the radiation surface region; An elastic dome having a hollow three-dimensional shape that can be elastically deformed protrudes at a position corresponding to the radiation surface region, the illumination sheet is disposed along the surface of the base portion, and the pressing operation is performed on the surface operation portion. In front of the illumination sheet It said resilient dome over the radiating surface area is characterized by being configured to be pressed elastically deformed.

  According to the illumination sheet of claim 1, the surface of the sheet-like core layer is formed in a mirror surface and covered with the cladding layer, and light traveling in the core layer is reflected at the interface between the core layer and the cladding layer. Thus, the light guided in the core layer can be prevented from being diffused and radiated on the surface of the core layer in a portion other than the radiation surface region. In addition, since the mirror surface of the core layer is covered with the clad layer, it is possible to prevent the surface of the core layer from being damaged, and it is also possible to prevent dust and the like from adhering to the surface even if formed on the mirror surface. Therefore, it is possible to prevent the light guided in the core layer from being radiated and attenuated by irregular reflection for a long period of time except for the radiation surface area.

  At the same time, since the surface of the core layer is roughened in the radiation surface region, the light traveling in the core layer is diffused and emitted from the core layer at the roughened portion. At this time, since the surface of the core layer is exposed from the opening of the cladding layer, the light emitted from the core layer is directly emitted without passing through the cladding layer. Therefore, it is possible to emit light from the radiation surface area with stronger light.

  Moreover, even if the core layer surface is exposed by opening the clad layer so that stronger light can be emitted, the portion is roughened, so that dust does not adhere to the mirror surface. Further, it is possible to prevent light emitted from the radiation surface area from being attenuated with time.

  Therefore, it is possible to provide an illuminating sheet capable of emitting stronger light from the radiation surface region while preventing light emission at portions other than the radiation surface region over a long period of time.

  According to the illumination sheet of claim 2, the surface of the core layer is roughened inside the periphery of the opening and formed into a mirror surface outside the periphery of the opening. It is easy to radiate light with a clear outline.

  According to the illumination sheet of claim 3, since a plurality of radiation surface regions are provided, light is emitted from a larger number of radiation surface regions than the number of light sources by allowing light from the light source to enter the core layer. Can do. At that time, since light attenuation is small at a portion other than the radiation surface area, it is possible to efficiently radiate light from a large number of radiation surface areas.

  According to the illumination sheet of claim 4, since the radiation surface region is a part that repeatedly undergoes deformation in the direction intersecting the surface, the opening of the clad layer is disposed at the part that undergoes repeated deformation, and the clad layer is Not placed. Therefore, since the cladding layer does not exist, it can be easily deformed, and the interface between the core layer and the cladding layer can be prevented from degrading due to repeated deformation and peeling, thereby improving durability. Is possible.

  According to the operation switch of the fifth aspect, since the illumination sheet can highly prevent light emission at a portion other than the radiation surface region, and at the same time, it is possible to emit stronger light from the radiation surface region. Thus, light from the light source can be efficiently emitted from the translucent display unit, and an efficient operation switch can be provided by suppressing the number of light sources and the amount of light.

  According to the operation switch of the sixth aspect, since the illumination sheet can highly prevent light emission at a portion other than the emission surface area, and at the same time, it is possible to emit stronger light from the emission surface area. The light from the light source can be efficiently emitted from the translucent display portion.

  Moreover, since the illumination sheet is disposed along the surface of the base portion and the radiation surface region is disposed in a three-dimensional shape along the dome portion, the angle of the light traveling while reflecting in the core layer with respect to the radiation surface region Is likely to be larger than in the case of a flat surface, and light is more easily emitted from the radiation surface region.

  At the same time, since the cladding layer is not provided in the irradiation surface area of the illumination sheet, even if the surface operation member is repeatedly pressed and the illumination sheet is repeatedly pressed and deformed, the core layer and the cladding layer It is difficult for deterioration such as peeling of the interface between them to occur, and durability can be improved.

  [Embodiment 1]

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 show the illumination sheet 10 of the first embodiment. The illumination sheet 10 is disposed, for example, on an opening portion of a housing or on a base body, with one surface exposed to the outside, and guides light supplied from a light source inside the sheet shape to a predetermined position. It is used so that it may radiate | emit from the radiation | emission surface area | region provided in this.

  In the first embodiment, as shown in FIGS. 1 and 2, the light is arranged on the base 11 and supplies light from the light source 13 such as an LED provided on the base 11 in the surface direction. Thus, light is emitted from the radiation surface area 15 provided at a plurality of positions.

  As shown in FIG. 3, the illumination sheet 10 includes a sheet-like core layer 21 for guiding light inside, and a clad layer 23 that covers one surface of the core layer 21. The surface of 21 is formed in a mirror surface, and the core layer 21 and the cladding layer 23 are in close contact with each other and are integrally joined.

  In the radiation surface region 15, an opening 25 is provided in the cladding layer 23, and the surface of the core layer 21 exposed from the opening 25 is roughened. This rough surface is formed on the entire inner side of the periphery 25a of the opening 25, and the outer side of the periphery 25a of the opening 25 is a mirror surface.

  A light source arrangement hole 29 is provided in the core layer 21 at an arrangement position of the light source 13 different from the radiation surface region 15, and an LED or the like that is fixedly provided on the substrate 11 when arranged on the substrate 11. The light source 13 is accommodated inside. Further, a light shielding layer 27 for shielding light from the light source 13 is provided on the surface of the cladding layer 23 around the position where the light source 13 is disposed.

  First, the core layer 21 of the illuminating sheet 10 is a layer having transparency and guiding light by transmitting light in the surface direction. The core layer 21 preferably has a total light transmittance of 80% or more of light in the visible light region. This is because the higher the transmittance is, the more the attenuation of the guided light can be suppressed.

  The refractive index of the core layer 21 is preferably as high as possible, for example, 1.3 or more. This is because the range of selection of materials that can be used as a clad layer described later can be expanded.

  The core layer 21 preferably has flexibility. This is because the illumination sheet can be deformed to be easily arranged along the surface shape of the substrate 11, and the degree of freedom of arrangement and use is improved.

  As a material constituting such a core layer 21, for example, a resin such as silicone, polyurethane, or polycarbonate, an elastomer, or the like can be used.

  The thickness of the core layer 21 can be appropriately selected according to the use of the core layer 21 and the like, but it is preferable that the core layer 21 be formed as thin as possible within a range in which desired luminance can be secured in the radiation surface region 15. However, the area of the incident surface on which the light from the light source 13 is incident facing the light source 13 needs to be at least 50% or more of the area of the light emitting surface on the opposite side of the light source 13.

  The surface of the core layer 21 on the cladding layer 23 side is required to be a mirror surface. If it is a mirror surface, it can suppress that the light guided is irregularly reflected by the interface of the core layer 21 and the clad layer 23, and light is radiated | emitted from the core layer 21 in parts other than the radiation | emission surface area | region 15, light guide performance is improved. This is because it can be improved.

  This mirror surface is a state in which the surface roughness is kept small. For example, when the core layer 21 is molded using a mold, the mirror surface can be produced by suppressing the surface roughness of the mold surface to be small. As the surface roughness of the mold surface, for example, an arithmetic average roughness (Ra) measured by a three-dimensional shape measuring device or the like is preferably in the range of 0.01 to 0.5 μm.

  The surface of the core layer 21 on the substrate 11 side is preferably a mirror surface as well as the surface on the cladding layer 23 side unless total reflection is possible on the surface of the substrate 11.

  The surface of the core layer 21 exposed from the opening 25 of the cladding layer 23 is required to be a rough surface. This is because the light guided in the core layer 21 is diffusely reflected and can be emitted from the surface of the core layer 21 due to the rough surface. At the same time, if the surface is rough, it is difficult to adhere even if dust comes into contact.

  This rough surface can be formed by various methods. For example, when the mirror surface of the core layer 21 is formed by a mold, the surface roughness at a predetermined position of the mold surface may be roughened. . In that case, as the surface roughness of the mold surface, for example, the arithmetic average roughness (Ra) measured by a three-dimensional shape measuring device or the like is preferably 1.0 μm or more. In order to prevent a deviation between the position of the opening of the clad layer 23 and the position to be roughened, it is also possible to form a rough surface by various methods together with the surface of the clad layer 23 after the clad layer 23 is formed. .

  Next, the clad layer 23 of the illumination sheet 10 is a layer laminated and integrated on at least one surface of the core layer 21, and the light in the core layer 21 is reflected at the interface with the core layer 21. This is a layer for guiding the inside of the core layer 21.

  The clad layer 23 needs to be at least smaller than the refractive index of the core layer 21, and is preferably smaller than the refractive index of the core layer 21 by 0.1% or more, and particularly preferably smaller than 1%. Is preferred. This is because as the refractive index of the cladding layer 23 increases, the conditions for total reflection of light guided through the core layer 21 become narrower and the light guide performance decreases.

  The clad layer 23 may be less transparent than the core layer 21. This is because, since the surface of the core layer 21 is a mirror surface, the light guided in the core layer 21 can be sufficiently reflected at the interface with the cladding layer 23, and the influence on the reflection conditions of the guided light is small.

  In the case of the clad layer 23 having transparency, light leaking from the core layer 21 may be emitted as weak light from a part or the whole of the clad layer 23. In that case, the design may be imparted by intentionally radiating the leaked light, and the leaked light is reflected on at least a part or all of the outer surface of the cladding layer 23 except the radiation surface region 15. For this purpose, a reflective coating such as a metal or a light shielding coating may be provided for shielding. When the reflective coating is provided, light leaked from the core layer 21 can be supplied to the core layer 21 again.

  Furthermore, the cladding layer 23 preferably has flexibility. This is because the illumination sheet can be deformed to be easily arranged along the surface shape of the substrate 11, and the degree of freedom of arrangement and use is improved.

  The material constituting the clad layer 23 is required to be a material that can be laminated and integrated with the core layer 21 without interposing other materials such as an adhesive. Specifically, fluororesins such as polytetrafluoroethylene, other resins, elastomers, and the like can be used. A material that can reduce the apparent refractive index by holding air in the porous space, such as silica, may be used.

  The thickness of the clad layer 23 is preferably as thin as possible within a range in which a protective function capable of preventing damage such as scratches from the outside can be secured on the mirror surface of the core layer 21. This is because the clad layer 23 is a layer used to reflect light guided in the core layer 21 at the interface with the core layer 21, and thus the thickness is less affected.

  The surface exposed to the outside of the cladding layer 23 is required to be rougher than at least the mirror surface of the core layer surface. This is because if it is formed on a mirror surface, dust and the like are likely to adhere. When the exposed surface of the clad layer 23 is molded using a mold, the surface roughness of the mold surface is, for example, an arithmetic average roughness (Ra) measured by a three-dimensional shape measuring device or the like. It is preferable that it is larger than 1.0 μm.

  Next, the light shielding layer 27 provided on the illumination sheet 10 is a layer that prevents the light from the light source 13 from being transmitted through the cladding layer 23 and directly emitted to the outside.

  The light shielding layer 27 is made of an opaque layer that can reliably shield light, and is preferably one that can be deformed together with the cladding layer 23. The light shielding layer 27 may be opaque and have a reflection effect. The light shielding layer 27 may be directly bonded to the clad layer 23 by printing or the like, but may be bonded via another layer such as an adhesive or a double-sided adhesive tape. This is because there is no influence on the light guided in the core layer 21 because it does not directly contact the core layer 21.

  As such a light shielding layer 27, for example, a resin such as silicone, polyurethane, or polycarbonate, an elastomer, a metal such as stainless steel, or aluminum can be used. As described above, when a light-shielding film or a reflective film is provided in order to prevent the clad layer 22 from emitting light as weak light, the film may be used as the light-shielding layer 27. The thickness of the light shielding layer 27 is preferably as thin as possible within a range where sufficient light shielding properties can be obtained.

  The light shielding layer 27 is disposed immediately above and around the light source 13 and is required not to exist in the radiation surface region 15. The light-shielding layer 27 is disposed until the incident angle is such that the light supplied from the light source 13 to the core layer 21 can be substantially totally reflected when the light reaches the interface between the core layer 21 and the cladding layer 23. It is preferable to arrange so as to cover the range.

  In order to manufacture the illumination sheet 10 having such a configuration, for example, a core layer forming sheet capable of forming the core layer 21 is prepared in advance so that the surface becomes a mirror surface. It can be manufactured by applying a paste or the like capable of forming the clad layer 23 on the mirror surface, except for the opening 25, using a jig or the like, and curing the paste. At that time, the surface of the core layer 21 exposed from the opening 25 may be roughened together with the production of the core layer 21 or after the cladding layer 23 is formed.

  In addition, a clad layer forming sheet having an opening 25 and having a mirror surface facing the core layer 21 is prepared in advance, and a paste or the like capable of forming the core layer 21 is applied to the clad layer forming sheet. It may be produced by curing. In that case, a transfer material capable of roughening the surface of the core layer 21 is disposed in the opening 25 of the clad layer forming sheet, and a rough surface is formed on the surface in the opening 25 of the core layer 21. Can do.

  In order to use such an illuminating sheet 10, light can be emitted from the radiation surface region 15 on the surface by causing the light source 13 to emit light while being arranged on the substrate 11.

  Here, first, when the light source 13 emits light, it is radiated from the point light source in all directions within the light source arrangement hole 29 of the core layer 21, supplied to the core layer 21 and the clad layer 23 and incident thereon. Light incident in a direction that substantially intersects the surface direction of the core layer 21 passes through the core layer 21 and the cladding layer 23, reaches the light shielding layer 27, and is shielded from light. Light incident on the surface direction of the core layer 21 under the condition that it can be totally reflected is guided through the inside of the sheet-like core layer 21 while being reflected by the cladding layer 23. And the light which reached the surface in the opening part 25 of the core layer 21 among the light is diffused by the roughened surface, and is emitted outside through the opening part 25. The remaining light is further guided in the core layer 21 and radiated to the outside in the same manner from the surfaces in the other openings 25.

  This makes it difficult for light to be emitted at portions other than the radiation surface region 15, and allows light to be emitted from the plurality of radiation surface regions 15 of the illumination sheet 10.

  According to the irradiation sheet 10 as described above, the sheet-shaped core layer 21 and the clad layer 23 covering the surface of the core layer 21 are provided, and the surface of the core layer 21 is a mirror surface in a portion other than the radiation surface region 15. Since it is formed, the light traveling in the core layer 21 can be sufficiently suppressed from being diffusely reflected and emitted from the surface of the core layer 21.

  Moreover, since the mirror surface of the core layer 21 is covered with the cladding layer 23, it is possible to prevent damage such as scratches from occurring on the surface of the core layer 21. At the same time, when the surface of the core layer 21 is formed into a mirror surface, when dust or the like comes into contact with the core layer 21, the dust easily adheres to the mirror surface, but this mirror surface is covered with the cladding layer 23. Even if it is formed on a mirror surface, it is possible to prevent dust and the like from adhering to the surface.

  Therefore, it is possible to sufficiently prevent the light guided in the core layer 21 from being radiated by irregular reflection and attenuated during the light guiding in a portion other than the radiation surface region 15 over a long period of time. It is.

  Furthermore, since the surface of the core layer 21 is roughened in the radiation surface region 15, the light traveling through the core layer 21 is easily diffused and radiated from the core layer 21 at the roughened portion. At that time, in the portion where the light is emitted, the surface of the core layer 21 is exposed from the opening 25 of the clad layer 23, so that the light emitted from the core layer 21 is directly emitted without passing through the clad layer 23. Is done. Therefore, it is possible to emit light from the radiation surface region 15 with stronger light.

  Moreover, even if the cladding layer 23 is opened and the surface of the core layer 21 is exposed so that stronger light can be emitted, the surface is roughened so that dust adheres like a mirror surface. This can prevent the light emitted from the radiation surface region 15 from being attenuated over time.

  Therefore, it is possible to radiate stronger light from the radiation surface region 15 while preventing light emission at portions other than the radiation surface region 15 over a long period of time.

  In the illumination sheet 10, the surface of the core layer 21 is roughened on the inner side of the peripheral edge 25 a of the opening 25 and is formed in a mirror surface on the outer side of the peripheral edge 25 a of the opening 25. The periphery of the light can be clarified and light with a clear outline can be easily emitted.

  Further, in the illumination sheet 10, since a plurality of radiation surface regions 15 are provided, light is emitted from more radiation surface regions 15 than the number of the light sources 13 by causing light from the light source 13 to enter the core layer 21. However, at that time, since the attenuation of light is small in a portion other than the radiation surface region 15, it is possible to efficiently emit light from a large number of radiation surface regions 15.

  The first embodiment can be appropriately changed within the scope of the present invention. For example, the example in which the cladding layer 23 is formed on one surface of the core layer 21 has been described above, but the cladding layer 23 may be formed on both surfaces of the core layer 21.

  In the above description, an example in which the rough surface exposed from the opening 25 of the core layer 21 and the surface of the mirror surface covered by the cladding layer 23 are formed in the same plane has been described. A part of the protrusions may be arranged and roughened.

Further, in the above description, the example in which the light source 13 is completely accommodated in the light source arrangement hole 29 of the core layer 21 has been described. For example, the light source 13 is disposed through the thickness of the illumination sheet 10. Even it can be used.
[Embodiment 2]

  4 and 5 show the second embodiment.

  The second embodiment is an example in which the illumination sheet 10 of the first embodiment is used for a mobile phone as an operation switch.

  As shown in FIGS. 4 and 5, the mobile phone includes a housing 30 having an opening 30a, an operation panel 31 serving as an operation switch cover member disposed in the opening 30a of the housing 30, and a housing. 30 is provided with a base portion 32 that is disposed to face and separate from the operation panel 31, and the illumination sheet 10 is disposed on the base portion 32 between the operation panel 31 and the base portion 32. The operation panel 31 can be irradiated from the back side.

  The operation panel 31 is provided with a plurality of pressing operation portions 35 arranged in the vertical and horizontal directions for performing a pressing operation as a switch operation from the front side. In addition, a substrate 33 is provided on the base portion 32, and contact terminals 37 connected to a circuit (not shown) and spaced apart from each other at positions facing the full pressing operation portion 35 of the operation panel 31 of the substrate 33. Between each pressing operation part 35 and the substrate 33, there is provided a pressing deformation part 39 for separating and contacting the contact terminals 37 and for providing an operational feeling during the pressing operation.

  The operation panel 31 includes a key sheet 41 as a surface operation unit having an operation surface 31a of the pressing operation unit 35, and a plunger sheet 43 capable of pressing the pressing deformation unit 39 by a pressing operation to the pressing operation unit 35. 30 are laminated in order from the outside of the opening 30a, and are joined by an adhesive, a double-sided PSA sheet or the like.

  The key sheet 41 of the operation panel 31 is made of a hard resin sheet or the like that is formed in a flat plate shape using a resin that can transmit light and is elastically deformable, such as polycarbonate and PET. In this embodiment, the key sheet 41 has a strength that can hold the shape of the operation panel 31 and can be pressed.

  The key sheet 41 is provided with an operation surface 31a of the pressing operation unit 35 on a surface exposed from the opening 30a of the housing 30, and light can be blocked on a surface opposite to the operation surface 31a. A light shielding layer 41a made of a printing layer is provided. At a predetermined position of the pressing operation unit 35 or the like, the light-transmitting display unit 45 that can transmit light by removing the light-shielding layer 41a in various shapes such as characters and diagrams, that is, without the light-shielding layer 41a. The light transmitted through the translucent display unit 45 is visible from the surface side of the operation panel 31. Here, the translucent display part 45 is provided with a colored translucent decorative print layer so that the translucent light is colored.

  The plunger sheet 43 of the operation panel 31 has a flat sheet-shaped portion 43b having a size including the pressing operation portions 35 at a plurality of positions of the key sheet 41, and a pressing operation on the surface of the sheet-shaped portion 43b facing the pressing deformation portion 39. And a plurality of plunger portions 43a each projecting at a position corresponding to the portion 35.

  The plunger sheet 43 is formed from polyurethane, polyester, polycarbonate, acrylic alone or a composite thereof, silicone rubber, or the like. The sheet-shaped portion 43b is formed to be thinner in order to form the operation panel 31 to be thin, and is formed to be significantly softer than the key sheet 41 in order to make it difficult to inhibit the elastic deformation of the key sheet 41. Has been. The plunger sheet 43 may be provided with notches (slits) to facilitate elastic deformation.

  On the other hand, the substrate 33 of the base portion 32 is made of a hard printed board, a flexible printed board, or the like, and is fixedly attached to the housing 30. A large number of circuits (not shown) are provided on the substrate 33, and contact terminals 37 are provided at positions corresponding to the pressing operation unit 35.

  Further, the pressing deformation portion 39 provided between the substrate 33 and the operation panel 31 includes a metal dome 47 as an elastic dome having a hollow solid shape that can be elastically deformed at each position corresponding to the pressing operation portion 35. ing. The metal dome 47 is disposed on the substrate 33 so as to protrude toward the operation panel 31.

  The metal dome 47 is always in contact with one of the contact terminals 37 at the periphery, and is disposed in a state of being separated from the other contact terminal 37 at the center, and is pressed by the plunger portion 43 a, whereby the metal dome 47 contacts the contact terminal 37. 37 is configured to be connected.

  The illumination sheet 10 is disposed along the upper surface of the metal dome 47 and the upper surface of the substrate 33, and is closely fixed to each other. In this state, the radiation surface region 15 of the illumination sheet 10 is disposed on the metal dome 47, and the rough surface of the core layer 21 exposed in the opening 25 of the cladding layer 23 is the pressing operation portion of the operation panel 31. 35 is disposed at a position corresponding to 35. Furthermore, the tip of the plunger portion 43 a of the plunger sheet 43 is in contact with a part of the rough surface of the core layer 21 in the opening 25.

  Therefore, when the pressing operation part 35 is pressed and displaced, the radiation surface area 15 of the illumination sheet 10 together with the metal dome 47 is repeatedly deformed in the direction intersecting the surface and displaced toward the substrate 33 side. Yes.

  In such a mobile phone, when the light source 13 (not shown) fixed to the substrate 33 emits light and the light is guided by the core layer 21, the opening of the cladding layer 23 in the radiation surface region 15 on the metal dome 47. Light is emitted from the surface of the core layer 21 in 25. This light is applied to the pressing operation unit 35 of the operation panel 31 from the back side, passes through the plunger sheet 43 and is applied to the translucent display unit 45. And the light which permeate | transmitted the translucent display part 45 can be visually recognized from the surface side of the key sheet 41. FIG.

  In order to perform the pressing operation, a part of the plurality of pressing operation portions 35 of the operation panel 31 is pressed from the operation surface 31 a side of the key sheet 41. Then, the operation panel 31 is elastically deformed by the elasticity of the key sheet 41, the plunger portion 43a of the plunger sheet 43 is lowered, and the pressing deformation portion 39 is pressed by the plunger portion 43a. Then, the metal dome 47 is elastically deformed together with the illuminating sheet 10, and the contact terminal 37 is electrically connected by the metal dome 47 in a state where a feeling of clicking operation is obtained, and various processes are executed.

  According to the mobile phone as described above, the effect similar to that of the first embodiment can be obtained by the illumination sheet 10.

  That is, since it is possible to radiate stronger light from the radiation surface region 15 while preventing the emission of light at portions other than the radiation surface region 15 over a long period of time, the operation panel 31 can be used for a long period of time. The emission of light from portions other than the translucent display unit 45 can be suppressed, and stronger light can be emitted from the translucent display unit 45. Further, since the periphery of the emitted light can be clarified, clearer light can be emitted from the translucent display portion 45.

  Moreover, in the illumination sheet 10, the radiation surface region 15 is disposed in a deformed portion that repeatedly undergoes deformation in the direction intersecting the surface, and therefore the clad layer 23 does not exist in the portion that undergoes repeated deformation. Therefore, it can be easily deformed due to the absence of the clad layer 23, and the interface between the core layer 21 and the clad layer 23 can be prevented from being peeled off by repeated deformation, and durability can be improved. .

  Further, since the illumination sheet 10 is disposed on the surface of the substrate 33 and the radiation surface region 15 is disposed in a three-dimensional shape along the metal dome 47, the radiation surface region 15 of light traveling while being reflected in the core layer 21. As compared with the case where the angle with respect to is flat, the angle tends to be large, and light is more easily emitted from the radiation surface region 15.

  In the second embodiment, the example in which the pressing operation unit 35 capable of pressing operation is provided on the operation panel 31 has been described. However, a contact operation for performing a contact operation may be performed.

  Moreover, although the example which consists of a hard resin sheet was demonstrated as the key sheet | seat 41 above, the through-hole was provided as the translucent display part 45 in the flat thin sheet | seat which consists of metals, such as stainless steel, for example, this penetration It may be made of other materials such as a composite material sheet in which a translucent resin is sealed in the holes.

Furthermore, in the above description, an example in which the illumination sheet 10 is in direct contact with the metal dome 47 and the substrate 33 has been described. However, in order to fix the metal dome 47 to the substrate 33 between the illumination sheet 10 and the metal dome 47 and the substrate 33. Other layers such as a metal dome fixing sheet may be interposed. In that case, a material made of a material having a refractive index smaller than that of the core layer 21 is preferable.
[Embodiment 3]

  6 and 7 show the third embodiment.

  The third embodiment is an example in which the illumination sheet 10 of the first embodiment is used for a mobile phone as an operation switch.

  In the mobile phone according to the third embodiment, unlike the second embodiment, the illumination sheet 10 is not disposed on the upper surface of the substrate 33, and the upper surfaces of the substrate 33 and the metal dome 47 are covered with a metal dome fixing sheet 48. ing.

  Further, the operation panel 31 is not provided, and instead, a push button sheet 55 as an operation switch cover member provided with a large number of push buttons 49 as a surface operation unit is provided. The push button sheet 55 is covered with a hard casing 30 from the upper surface side, and each push button 49 is exposed from a plurality of button openings 30b provided in the casing 30, and is arranged so as to be pressed. . Each push button 49 is provided with a flange portion 49a, and this flange portion 49a is accommodated in an enlarged diameter portion 30c provided on the substrate 33 side of the button opening portion 30b. The push button sheet 55 is supported by the housing 30 from the upper surface side.

  This push button sheet 55 includes an illumination sheet 10, and each push button 49 is disposed on a large number of radiation surface regions 15 of the illumination sheet 10 and is fixed on the surface of the cladding layer 23. The push button 49 is disposed so as to cover the opening 25 of the clad layer 23, and a light shielding layer 51 made of a print layer capable of blocking light is provided on the back side of the push button 49, so that the translucent display portion 45 is provided. Is formed. Further, the upper surface of the illumination sheet 10 where the push button 49 is not disposed is covered with the housing 30.

  A plunger sheet 43 similar to that of the second embodiment is joined to the illumination sheet 10 on the side of the substrate 33, with the exception of the outer peripheral portion, with no adhesive means interposed. It is preferable that the plunger sheet 43 is formed of a material having a lower refractive index than the core layer 21 because the light guide property of the core layer 21 can be improved.

  Others are the same as in the second embodiment.

  Even in such a cellular phone, as in the second embodiment, the emission of light from portions other than the translucent display unit 45 is suppressed over a long period of time, and the translucent display unit 45 is stronger and clearer. It is possible to emit light.

  Moreover, in the third embodiment, the radiation surface region 15 of the illumination sheet 10 can be directly irradiated by being arranged close to the back surface of the push button 49 to be irradiated, so that it can be irradiated with stronger light, and the transparent The light emitted through the light display unit 45 can be made stronger.

  Further, since the illumination sheet 10 and the push button 49 are disposed and supported in the housing 30, the clad layer 23, the core layer 21, and the sheet shape portion 43b of the plunger sheet 43 can be formed sufficiently flexibly, It can be formed thin, and the operability during the pressing operation of the push button 49 can be improved, and a clear click operation feeling by the metal dome 47 can be easily obtained.

In the third embodiment, the example in which the plunger sheet 43 is formed separately from the core layer 21 has been described. However, the plunger portion 43a of the plunger portion 43 can be formed integrally with the core layer 21.
[Embodiment 4]

  8 and 9 show the fourth embodiment. The fourth embodiment is an example in which the illumination sheet 10 is used for a mobile phone as an operation switch, as in the third embodiment.

  In this mobile phone, an operation panel 55 is provided in the opening 30 a of the housing 30. In this operation panel 55, a key sheet 56 having a plurality of operation surfaces 55a is arranged on the surface side, and the illumination sheet 10 and the plunger sheet 43 are laminated and integrated on the substrate 33 side of the key sheet 56 without interposing an adhesive means. Has been configured.

  The key sheet 56 of the operation panel 55 is made of a hard resin sheet or the like that is made of a resin that can transmit light and is elastically deformable, such as polycarbonate and PET, and has a sufficient shape of the operation panel 55. It is strong enough to be pressed and elastically deformed. In the key sheet 56, a large number of operation surfaces 55a are defined by penetrating slits 57 formed in three directions in a substantially U shape.

  The illumination sheet 10 of the operation panel 55 is configured in the same manner as in the third embodiment, but the clad material 23 is formed of an elastomer or a soft resin, and a part of the clad material 23 is a key sheet 56. The through slit 57 is sealed.

  Further, in the operation panel 55, the core layer 21 and the clad layer 23 of the illumination sheet 10 and the plunger sheet 43 are formed sufficiently softer than the key sheet 56, and the illumination sheet 10 and the plunger sheet 43 are composed of the key sheet 56. It is supported by.

  Other configurations are the same as those of the third embodiment.

  Even in the case of a mobile phone having such an operation panel 55, as in the first embodiment, the light transmission from the portion other than the translucent display unit 45 can be suppressed for a long period of time, and the translucent display unit 45 can be controlled. It is possible to emit stronger and clearer light. Further, as in the third embodiment, the radiation surface area 15 of the illumination sheet 10 can be disposed close to the back surface of the key sheet 56 to be irradiated and can be irradiated with stronger light.

  Moreover, in this mobile phone, each operation surface 55a is partitioned by the through slit 57, and the inside of this through slit 57 is sealed by the soft clad layer 23, so that each operation surface 55a is elastically deformed during the pressing operation. It is easy to do, and it is hard to give influence, such as a deformation | transformation, to the adjacent operation surface 55a, when a part of operation surface 55a is pressed. Therefore, the operability during the pressing operation can be improved, and a clear click operation feeling can be easily obtained. At the same time, since the through slit 57 is sealed by the clad layer 23, it is possible to prevent dust and moisture from entering through the through slit 57.

  In addition, although the example which consists of a hard resin sheet was demonstrated as the key sheet | seat 56 above, the translucent display part 45 is provided in the flat thin sheet | seat which consists of metals, such as stainless steel, similarly to Embodiment 2, for example. It may be made of another material such as a sheet made of a composite material in which a through-hole is provided and a translucent resin is sealed in the through-hole.

It is a top view of the illumination sheet of Embodiment 1 of this invention. It is AA sectional drawing of FIG. 1 of the same Embodiment 1. FIG. It is BB sectional drawing of FIG. 1 of the illumination sheet of the Embodiment 1. FIG. It is a fragmentary top view of the mobile telephone of Embodiment 2 of this invention. It is CC sectional drawing of FIG. 4 of the Embodiment 2. FIG. It is a partial top view of the mobile phone of Embodiment 3 of this invention. It is DD sectional drawing of FIG. 6 of Embodiment 3 of this invention. It is a partial top view of the mobile phone of Embodiment 4 of this invention. It is EE sectional drawing of FIG. 8 of Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Illumination sheet 11 Base | substrate 13 Light source 15 Radiation surface area 21 Core layer 23 Cladding layer 25 Opening part 27 Light shielding layer 30 Case 31 Operation panel 33 Substrate 35 Press operation part 39 Press deformation part 41 Key sheet 43 Plunger sheet 45 Translucent display part 47 Metal Dome

Claims (6)

In an illumination sheet in which light from a light source is guided through a sheet-like interior and is emitted from a predetermined radiation surface area,
A sheet-like core layer having a mirror-like surface and a cladding layer covering the surface of the core layer, and configured to be guided in the core layer while being reflected by the cladding layer;
The cladding layer has an opening in the radiation surface region, the surface of the core layer is exposed in the opening, and the exposed surface of the core layer is roughened. Illuminated sheet.   2. The illumination sheet according to claim 1, wherein the surface of the core layer is roughened inside the periphery of the opening and is formed into a mirror surface outside the periphery of the opening.   The illumination sheet according to claim 1, wherein a plurality of the radiation surface regions are provided.   The illumination sheet according to any one of claims 1 to 3, wherein the radiation surface region is a deformed portion that repeatedly undergoes deformation in a direction intersecting the surface. A surface operation unit that performs a switch operation from the surface side, an illumination sheet according to any one of claims 1 to 4 disposed on a back side of the surface operation unit, and supplying light to the illumination sheet An operation switch with a light source,
The surface operation unit has a translucent display unit configured to transmit light from the radiation surface region and be viewed from the surface side at a position corresponding to the radiation surface region of the illumination sheet. Features an operation switch. 5. A surface operation unit that performs a pressing operation from the front surface side, a base unit that is spaced from and opposed to the surface operation unit, and the surface operation unit and the base unit that are disposed between the surface operation unit and the base unit. An operation switch comprising the illumination sheet according to any one of the above and a light source that supplies light to the illumination sheet,
The surface operation unit has a translucent display unit configured to transmit light from the radiation surface region and be viewed from the surface side at a position corresponding to the radiation surface region of the illumination sheet,
The base portion is provided with an elastic dome having a hollow three-dimensional shape that can be elastically deformed at a position corresponding to the radiation surface region of the illumination sheet,
The illumination sheet is disposed along the surface of the base portion,
The operation switch is configured such that when the pressing operation is performed on the surface operation unit, the elastic dome is pressed and elastically deformed through the radiation surface area of the illumination sheet.

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