JP2008251367A - Lightening sheet structure, its manufacturing method, and cover member for operation switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightening sheet structure capable of acquiring an excellent appearance and radiating light in a designated shape and easy manufacturing. <P>SOLUTION: In the lightening sheet structure having a lightening sheet 10 for radiating light of a light source 13 from a designated radiating surface zone 15 by guiding through the sheet-like inside, and a surface covering section 12 for covering the lightening sheet 10, the lightening sheet 10 has a sheet-like core layer 21, and a clad layer 23 covering by firmly sticking on the surface of the core layer 21, and the light of the light source 13 is constituted to guide through the core layer 21 while the light is reflected by the clad layer 23. The clad layer 23 has an opening 25 for radiation purpose which opens in the radiating surface zone 15 at a designated shape, the surface covering section 12 has a covering-up layer 16 which reduces visibility at a lightening sheet 10 side and can be visible on the surface side, and the light radiated from the opening 25 for radiation purpose can be visible at the surface side by transmitting the covering-up layer 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an illumination sheet structure that is arranged on the surface of various components and can conceal the inside and emit light of a predetermined shape, a manufacturing method thereof, and a cover member for an operation switch using the illumination sheet structure. About.

  In recent years, an illumination sheet structure using an illumination sheet configured to guide light from a light source through a sheet-like interior and emit the light in a predetermined radiation surface area on the surface has been proposed in various fields.

  For example, Patent Document 1 below proposes a keypad provided with at least one reflection pattern for reflecting a part of light spreading in the light guide plate to the surface side. Here, since the reflection pattern is partially provided, light can be emitted from a part of the surface.

  In order to construct a keypad assembly using this keypad, a light guide plate is laminated on a switch board having a dome portion, a reflection pattern is disposed on the dome portion, and a key button is positioned at a position facing the dome portion. Place. In this keypad device, the light guided by the light guide plate is diffusely reflected by the reflection pattern and emitted, so that the key button can be illuminated from the back side.

In this keypad assembly, a printing layer of a predetermined shape such as letters and numbers is applied to the upper surface of the key button, and the inner side of the key button is hidden by this printing layer so that it cannot be seen from the outside. When illuminated from the side, the light transmitted through the printing layer is visible from the outside.
JP 2006-323843 A

However, in such a conventional structure such as a keypad, the entire print layer is displayed by the light emitted by the reflection pattern of the light guide plate. For this reason, light cannot be emitted from the printed layer in a predetermined shape, and it has been difficult to obtain an excellent appearance.

  Accordingly, an object of the present invention is to provide an illumination sheet structure that can emit light in a predetermined shape, easily obtain an excellent appearance, and is easy to manufacture. Another object is to provide a manufacturing method, and another object is to provide a cover member for an operation switch using the illumination sheet structure.

  The illumination sheet structure according to claim 1, which solves the above-described problem, covers the illumination sheet, an illumination sheet in which light from a light source is guided through a sheet-shaped interior and is emitted from a radiation surface region having a predetermined shape. In the illumination sheet structure including a surface covering portion, the illumination sheet includes a sheet-like core layer and a clad layer that covers the surface of the core layer in close contact, and light from the light source is transmitted to the clad layer. The cladding layer includes a radiation opening that is opened in the same shape as the radiation surface region, and the surface covering portion is viewed from the surface side and is reflected by the core layer while being reflected by A concealing layer for reducing visibility on the side of the illumination sheet is provided, and the light emitted from the radiation opening is configured to be visible from the surface side through the concealing layer.

  The illumination sheet structure according to claim 2 is characterized in that, in addition to the configuration according to claim 1, the concealing layer is laminated in close contact with the cladding layer in a state of covering the radiation opening. And

  The illumination sheet structure according to claim 3 is characterized in that, in addition to the configuration according to claim 1 or 2, the core layer and the clad layer are formed to be colorless and transparent.

  The method for manufacturing an illumination sheet structure according to claim 4 is a method for manufacturing the illumination sheet structure according to any one of claims 1 to 3, wherein the core layer and the radiation opening having a predetermined shape are used. And forming the illumination sheet including the cladding layer, and stacking and integrating the surface covering portion having the concealing layer covering the radiation opening and the cladding layer on the illumination sheet.

  An operation switch cover member according to a fifth aspect includes the illumination sheet structure according to any one of the first to third aspects, wherein the surface covering portion is switch-operable from the front side, The surface covering portion and the illumination sheet are integrally formed.

  According to the illuminating sheet structure of claim 1, the illuminating sheet is configured to guide the light from the light source in the core layer while reflecting the light from the clad layer, and the radiating opening is provided in the clad layer. The surface covering portion that covers the sheet is visually recognized from the surface side and includes a concealing layer that reduces the visibility of the illumination sheet side, and the light emitted from the radiation opening portion is configured to be visible from the surface side through the concealing layer. Therefore, when light is emitted from the light source, light is not easily emitted from the illumination sheet in the region other than the radiation surface region, and the concealing layer is visually recognized from the surface side of the surface covering portion. On the other hand, in the radiation surface region, light having a predetermined shape is emitted from the radiation opening, and this light is transmitted through the concealing layer and viewed from the surface side of the surface covering portion. Therefore, when light is radiated from the light source, it is possible to visually recognize light of a predetermined shape together with the concealing layer from the surface side of the surface operation unit, and an excellent appearance can be obtained.

  In addition, since it is not necessary to form a light transmitting part and a light shielding part separately from the illumination sheet in order to radiate light of a predetermined shape, the manufacturing can be extremely simplified.

  According to the illumination sheet structure of the second aspect, since the shielding layer covers the radiation opening and is laminated in close contact with the clad layer, the light emitted from the radiation opening is directly incident on the shielding layer. And irregular reflection or the like hardly occurs between the illumination sheet and the surface covering portion. Therefore, it is easy to form a clear outline of light in the shape of the radiation opening.

  According to the illumination sheet structure according to claim 3, since the core layer and the clad layer are formed to be colorless and transparent, the concealing layer has translucency enough to transmit the light emitted from the radiation opening. Even if it has, since the illumination sheet is difficult to be visually recognized from the surface side of the surface covering portion, it is not necessary to separately provide a layer or the like for shielding the back side of the concealing layer, and it is easier to manufacture.

  According to the method for manufacturing the illumination sheet structure according to claim 4, after forming the illumination sheet by forming the cladding layer with the radiation opening having a predetermined shape, the radiation opening and the cladding layer are covered. The illumination sheet structure can be easily manufactured without forming a separate layer for emitting light in a predetermined shape simply by forming a surface covering portion having a concealing layer.

  According to the operation switch cover member of the fifth aspect, since it comprises the illumination sheet structure according to any one of the first to third aspects, it is easy to obtain an excellent appearance and at the same time radiates light in a predetermined shape. It is possible and easy to manufacture.

  [Embodiment 1]

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

  1 to 3 show an illumination sheet structure according to the first embodiment.

  The illumination sheet structure covers the illumination sheet 10 provided with a radiation surface region 15 that emits light of a predetermined shape at a predetermined position, and the surface side of the illumination sheet 10, and transmits light emitted from the illumination sheet 10. And the surface covering portion 12 radiated to the surface side. The illumination sheet 10 is fixed to the fixing portion 11 a of the support base 11 in a state where the illumination sheet 10 is bonded to the surface covering portion 12.

  As shown in FIGS. 1 and 2, the fixing portion 11 a of the support base 11 is provided with a light source 13 such as an LED that can supply light to the illumination sheet 10 in the surface direction. Is guided by the illumination sheet 10 and can be emitted from the radiation surface region 15.

  More specifically, 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 covering one surface of the core layer 21. The core layer 21 and the clad layer 23 are in close contact with each other and are integrally joined. In the illumination sheet 10, a radiation opening 25 having the same shape as the radiation surface region 15 is formed in the cladding layer 23.

  The core layer 21 is a layer having transparency and guiding light by transmitting light in the surface direction. The core layer 21 is preferably a layer having 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 core layer 21 is preferably colorless and transparent. This is because the illumination sheet 10 can be covered with a concealing layer 16 to be described later, so that the illumination sheet 10 can be hardly seen from the surface.

  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 the cladding layer 23 can be expanded.

  The core layer 21 preferably has flexibility. This is because the degree of freedom of arrangement and application is improved, for example, the illumination sheet can be deformed to be easily arranged along the surface shape of the support base 11 and the surface covering portion 12.

  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 preferably 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 support base 11 side is also preferably a mirror surface like the surface on the cladding layer 23 side. This is because it is easy to improve the light guiding performance.

  And it is preferable that the light emission part 26 for making it easy to radiate | emit the light in the shape corresponding to the radiation opening part 25 is provided in the site | part in which the radiation opening part 25 of the core layer 21 is provided. The light radiating portion 26 makes it easier to radiate light guided in the core layer 21 than the cladding layer 23. For example, the light radiating portion 26 may be configured so as to diffusely reflect the guided light. In the first embodiment, the surface of the core layer 21 exposed from the radiation opening 25 to the surface covering portion 12 side is roughened from the surface of the core layer 21 covered by the cladding layer 23. Yes. This is because the light guided in the core layer 21 is diffusely reflected and easily emitted from the surface of the core layer 21 due to the rough surface.

  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.

  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 refractive index of the cladding layer 23 needs to be at least smaller than the refractive index of the core layer 21, and is preferably 0.1% or more smaller than the refractive index of the core layer 21, and particularly smaller by 1% or more. It is preferable to do. 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. The clad layer 23 is preferably colorless and transparent.

  Furthermore, the cladding layer 23 preferably has flexibility. This is because the illumination sheet can be deformed and easily arranged along the surface shapes of the support base 11 and the surface covering portion 12, 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 cladding layer 23 is preferably as thin as possible. 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.

  Next, the surface covering portion 12 of the illumination sheet structure includes a surface plate 14 covering the entire surface of the illumination sheet 10 and a concealing layer 16 laminated on the entire surface of the surface plate 14 on the illumination sheet 10 side. ing.

  The surface plate 14 of the surface covering portion 12 is made of a plate material capable of transmitting light such as various transparent resins and glass. The surface plate 14 only needs to have transparency that allows the concealment layer 16 to be visually recognized from the surface side of the illumination sheet structure, and can protect the concealment layer 16 and the illumination sheet 10. In the first embodiment, it is preferable that the surface plate 14 can ensure the rigidity as the illumination sheet structure.

  The concealing layer 16 of the surface covering portion 12 reduces the internal visibility on the side of the illumination sheet 10 from the surface covering portion 12, making it difficult to see the inside from the surface side, and at the same time, radiating from the radiation surface region 15 of the illumination sheet 10. It is a layer that transmits the transmitted light.

  The concealing layer 16 may have a total light transmittance of 5 to 45% in the visible light region, and is preferably 10 to 30%. This is because if the transmittance is too high, the inside is easily visible, while if it is too low, the light emitted from the radiation surface region 15 of the illumination sheet 10 is difficult to be transmitted to the surface side.

  As such a concealing layer 16, for example, a metal vapor deposition film formed by physical vapor deposition, chemical vapor deposition, electroplating, chemical plating, or the like having a translucency with a metal such as indium, tin, and aluminum. And a colored layer by screen printing or painting.

  On the other hand, as shown in FIGS. 1 and 2, the light source 13 is provided at an arrangement position different from the radiation surface region 15, and a light source arrangement hole 29 is provided in the core layer 21, and the light source 13 such as an LED or the like. Is housed inside. In the vicinity of the arrangement position of the light source 13, a light shielding layer 27 that shields light from the light source 13 is provided on the surface of the cladding layer 23.

  As shown in FIG. 2, the light shielding layer 27 is a layer that prevents light from the light source 13 from passing through the cladding layer 23 and being directly emitted to the outside, and is disposed immediately above and around the light source 13. ing. 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.

  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. 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.

  Such an illumination sheet 10 is used by being mounted so as to conceal the inside of various members.

  First, while the light is not emitted from the light source 13, the concealing layer 16 is visually recognized from the surface side over the entire surface covering portion 12.

  When light is emitted from the light source 13, the illumination sheet 10 is radiated in all directions from the point light source in the light source arrangement hole 29 of the core layer 21, and is supplied to and incident on the core layer 21 and the cladding layer 23. 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 radiation | emission opening part 25 of the core layer 21 among the lights is irregularly reflected by the roughened surface, and is radiated | emitted outside through the radiation | emission opening part 25. FIG. 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 radiation openings 25.

  At this time, since it is difficult for light to be emitted from the illumination sheet 10 in regions other than the radiation surface region 15, the concealing layer 16 is visually recognized from the surface side of the surface covering portion 12. On the other hand, in the radiation surface region 15, light having a predetermined shape is emitted from the radiation opening 25, and this light passes through the shielding layer 16 and is visually recognized from the surface side. Therefore, when light is emitted from the light source, light having a predetermined shape is visually recognized together with the concealment layer 16 from the surface side of the surface operation unit 12.

  Next, the manufacturing method of such an illumination sheet structure is demonstrated.

  First, in order to manufacture the illuminating sheet 10, for example, a core layer forming sheet material capable of forming the core layer 21 is prepared in advance so that the surface becomes a mirror surface, and a cladding layer is formed on the surface for forming the core layer. 23 is formed in close contact. At this time, it is necessary to provide a radiation opening 25 having a predetermined shape.

  In order to form the cladding layer 23 by providing the radiation opening 25, for example, printing may be performed so as to form the radiation opening 25 using a printing ink or the like capable of forming the cladding layer 23. Alternatively, the radiation opening 25 may be formed by placing a jig or the like at a position corresponding to the radiation opening 25, applying a paste or the like that can form the clad layer 23, and removing and curing the jig. it can.

  The surface of the core layer 21 exposed from the radiation opening 25 may be roughened together with the production of the core layer 21 or after the formation of the cladding layer 23.

  After the illumination sheet 10 is formed, for example, the surface covering portion 12 is formed by laminating the concealing layer 16 on the surface plate 14 formed in advance, and this surface covering portion 12 is formed by the cladding layer 23 and its radiation opening portion. 25 may be laminated and bonded so as to cover 25.

  Further, the concealing layer 16 may be formed by coating or the like so as to cover the cladding layer 23 of the illumination sheet 10 and the radiation opening 25, and the surface plate 14 may be laminated and bonded thereto.

  According to the irradiation sheet 10 as described above, while the light is not emitted from the light source 13, the concealment layer 16 is visually recognized on the entire surface covering portion 12, and when the light is emitted from the light source, the surface covering portion 12 conceals the light. While the layer 16 is visually recognized, light of a predetermined shape is visually recognized. Therefore, when viewed from the surface side of the surface covering portion 12, the inside is always concealed by the concealing layer 16, design properties can be imparted by the concealing layer 16, an excellent appearance is easily obtained, and the light source 13 Light of a predetermined shape can be emitted.

  In addition, since light of a predetermined shape can be emitted from the radiation opening 25 of the cladding layer 23 for guiding light, it is necessary to provide a layer for emitting light of the predetermined shape separately from the illumination sheet 10. In addition, the illumination sheet structure can be easily manufactured.

  Moreover, in this illumination sheet structure, since the shielding layer 16 is laminated in close contact with the cladding layer 23 and the radiation opening 25, the light emitted from the radiation opening 25 can be directly incident on the shielding layer 16. And irregular reflection or the like hardly occurs between the illumination sheet 10 and the surface covering portion 12. As a result, the outline of the light having the shape of the radiation opening 25 can be clearly formed.

  Further, since the core layer 21 and the clad layer 23 are colorless and transparent, even if the concealing layer 16 has a light-transmitting property that allows the light emitted from the radiation opening 25 to pass therethrough, it is illuminated. The sheet 10 is hardly visible from the surface side of the surface covering portion 12, and it is not necessary to provide a layer for shielding the back side of the concealing layer 16.

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

  In the first embodiment, 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 penetrates to the cladding layer 23 side of the illumination sheet 10. Even if it is arranged, it can be used.

  Further, in the above description, the light emitting portion 26 provided in the core layer 21 is configured to be roughly reflected by roughening the surface exposed from the radiation opening 25 of the cladding layer 23. A material having a higher refractive index than that of the cladding layer 23 may be disposed in close contact with the core layer 21, or the core layer 21 may be disposed so as to protrude into the radiation opening 25. Further, when the shielding layer 16 is laminated in direct contact with the surface of the core layer 21 so that light is more easily emitted than the cladding layer 23, the surface of the core layer 21 exposed from the radiation opening 25 is roughened. The shielding layer 16 may be brought into close contact without being surfaced.

  In the above description, the example in which the surface covering portion 12 is bonded to the surface of the illumination sheet 10 has been described. However, the surface covering portion 12 and the illumination sheet 10 may be disposed apart from each other.

Further, in the above description, an example in which the concealing layer 16 is laminated on the surface plate 14 as the surface covering portion 12 has been described. However, the surface covering portion 12 including the concealing layer 16 is provided directly on the surface of the illumination sheet 10. May be.
[Embodiment 2]

  4 and 5 show the second embodiment.

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

  As shown in FIGS. 4 and 5, the cellular phone includes a housing 30 having an opening 30 a, an operation panel 31 as an operation switch cover member disposed in the opening 30 a of the housing 30, and a housing 30 includes a base portion 32 disposed opposite to and spaced from the operation panel 31, and a light source 13 such as an LED that is fixed to the base portion 32 and supplies light to the operation panel 31.

  Specifically, the base portion 32 is provided with a substrate 33, and contact terminals 37 connected to a circuit (not shown) and spaced apart from each other are provided at predetermined positions of the substrate 33. A metal dome 47 is provided for separating and connecting the terminals 37 and for providing an operational feeling during a pressing operation. The metal dome 47 and the substrate 33 are covered with an elastically deformable sheet 48, so that the switch dome can be operated. A pressing deformation portion 39 that is elastically deformed is formed.

  The substrate 33 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 metal dome 47 is disposed at a position corresponding to each switch position and has an elastic dome shape having a hollow solid shape that can be elastically deformed. The metal dome 47 protrudes on the substrate 33 toward the operation panel 31 side. It is arranged to become.

  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 a plunger portion 43a described later, whereby the metal dome 47 The contact terminals 37 are connected to each other.

  On the other hand, the operation panel 31 can irradiate the key sheet 41 having the operation surface 31a of the pressing operation unit 35, the masking layer 16 formed on the back surface of the key sheet 41, and the key sheet 41 and the masking layer 16 from the back side. The illumination sheet 10 and a plunger sheet 43 capable of pressing the pressing deformation portion 39 by a pressing operation to the pressing operation portion 35 are laminated and joined in order from above.

  The illuminating sheet 10 of the operation panel 31 supplies light from the light source 13 in a direction along the surface, whereby light is emitted from the radiation surface area 15 provided at a plurality of positions corresponding to the respective pressing operation portions 35 of the operation panel 31. Is configured in the same manner as in the first embodiment. At the position of each pressing operation portion 35, there is provided a radiation opening 25 formed in various shapes such as letters and diagrams (for example, numerical shapes such as 1, 2 etc.).

  The key sheet 41 of the operation panel 31 is made of a hard resin sheet formed in a flat plate shape by 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 the key sheet 41 is provided on a surface on the side of the illumination sheet 10 opposite to the operation surface 31a. A concealing layer 16 similar to that of the first embodiment is provided, and the inner side visibility of the mobile phone is lowered so that it can be seen from the front side of the key sheet 41.

  The concealment layer 16 is uniform so that the shape display unit 16a formed in various shapes such as characters and diagrams at the position of the pressing operation unit 35 and other portions are colored in a different color from the shape display unit 16a. And a uniformly colored portion 16b formed on the surface. The shape display portion 16 a is formed on the radiation opening 25 of the illumination sheet 10 and has a similar shape to that of the radiation opening 25. On the other hand, the uniform display portion 16 b is formed on the cladding layer 23 of the illumination sheet 10. Although it is preferable that light is not transmitted through the portion where the uniform colored portion 16b is provided, since the light is not emitted from the cladding layer 23, the uniform colored layer 16b does not need to have sufficient light shielding properties.

  The plunger sheet 43 of the operation panel 31 includes a plurality of plungers that protrude from the flat sheet-shaped part 43b having a size including the pressing operation parts 35 at a plurality of positions of the key sheet 41 and the pressing deformation part 39, respectively. Part 43a.

  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.

  In the mobile phone having such a configuration, while light is not emitted from the light source 13 (not shown) fixed to the substrate 33, the shape display portion 16a and the uniform coloring portion 16b of the concealment layer 16 are formed from the surface side over the entire surface of the operation panel 31. Is visible.

  When light is emitted from the light source 13, in the illumination sheet 10, the light is guided through the inside of the sheet-like core layer 21 while being reflected by the cladding layer 23. The light reaching the surface in the radiation opening 25 of the core layer 21 is diffusely reflected and emitted from the radiation opening 25, is transmitted through the shape display portion 16a of the concealing layer 16, and is emitted to the surface side of the key sheet 41 for visual recognition. Is done. On the other hand, since light is not emitted from the cladding layer 23 in a region other than the radiation surface region 15, the uniform colored portion 16 b of the concealing layer 16 is visually recognized from the surface side of the key sheet 41.

  Furthermore, 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 entire operation panel 31 including the illumination sheet 10 is elastically deformed, 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, in a state where the metal dome 47 is elastically deformed and a feeling of clicking is obtained, the metal dome 47 conducts between the contact terminals 37, and various processes are executed.

  According to the mobile phone as described above, the same effect as that of the first embodiment can be obtained by the illumination sheet 10, and the inside of the mobile phone is always concealed by the concealing layer 16 from the surface side of the operation panel 31. 16 design properties can be imparted, an excellent appearance can be easily obtained, and light of a shape such as a predetermined character can also be emitted. In addition, since the light having a predetermined shape can be emitted by the clad layer 23 for guiding light, the operation panel 31 can be easily manufactured.

  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, a through-hole was provided in the flat thin sheet | seat which consists of metals, such as stainless steel, for example, and translucent resin is put into this through-hole. It may be made of other materials such as a sheet made of a composite material that is enclosed and configured to transmit light from the radiation opening 25.

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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Illumination sheet 11 Support base body 12 Surface covering part 13 Light source 15 Radiation surface area 16 Hiding layer 21 Core layer 23 Clad layer 25 Radiation opening part 27 Light shielding layer 30 Housing | casing 31 Operation panel 33 Board | substrate 35 Press operation part 39 Press deformation | transformation part 41 Key Seat 43 Plunger seat 47 Metal dome

Claims (5)

In an illumination sheet structure including an illumination sheet in which light from a light source is guided through a sheet-shaped interior and is emitted from a radiation surface region having a predetermined shape, and a surface covering portion that covers the illumination sheet,
The illumination sheet includes a sheet-like core layer and a clad layer that covers the core layer in close contact so that light from the light source is guided in the core layer while being reflected by the clad layer. Configured,
The clad layer includes a radiation opening having an opening having the same shape as the radiation surface region,
The surface covering portion includes a concealing layer that is visible from the surface side and reduces the visibility on the side of the illumination sheet,
An illumination sheet structure characterized in that the light emitted from the radiation opening is configured to be visible from the surface side through the concealing layer.   The illumination sheet structure according to claim 1, wherein the concealing layer is laminated in close contact with the cladding layer in a state of covering the radiation opening.   The illumination sheet structure according to claim 1, wherein the core layer and the cladding layer are formed to be colorless and transparent. A method for producing the illumination sheet structure according to any one of claims 1 to 3,
Forming the illumination sheet comprising the core layer and the cladding layer having the radiation opening of a predetermined shape;
A method for producing an illuminating sheet structure, wherein the surface covering portion having the concealing layer covering the radiation opening and the cladding layer is laminated and integrated with the illuminating sheet.   It consists of the illumination sheet structure as described in any one of Claims 1 thru | or 3, The said surface coating part can be switch-operated from the surface side, and this surface coating part and the said illumination sheet are integrally formed. An operation switch cover member.

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