JP2010015809A - Key sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin key sheet having a soft touch feeling, excellent in durability and having a new design capable of changing a display element when illuminated with back light and when not illuminated. <P>SOLUTION: An operation surface is formed by a soft touch skin layer 4 and a porous layer of the low compression elastic modulus is laminated on the backside of the skin layer 4 to achieve the layered and thin key sheet 1 having the soft touch feeling. When not illuminated, a first decorative part 5 formed on a front surface side of the porous layer 7 is visually confirmed and when illuminated, a second decorative part 9 formed on the backside of the porous layer 7 is visually confirmed in relief together with the first decorative part 5. Thus, the decorative design can be changed when not illuminated and when illuminated, thereby the key sheet 1 of the new design can be achieved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is used in an operation unit of various electronic devices such as a portable information terminal device, PDA, AV device, various remote controllers, various keyboards, and the like. The present invention also relates to a key sheet having a “soft touch feeling”.

  Electronic devices such as portable information terminals and PDAs have been reduced in size and thickness, and key sheets used in electronic devices are also required to be reduced in size and thickness. As a key sheet that meets such demands, for example, a thin key sheet having an operation plate made of metal or hard resin is known (Patent Document 1).

In addition, in order to enhance the design value and differentiate the key sheet, it has been studied to decorate it with a soft touch feeling at the time of operation. However, a synthetic leather layered on the surface of the resin molded product has been studied. Since a decorative sheet is known (Patent Document 2), if this decorative sheet is diverted to a key sheet, a thin key sheet having a soft touch feeling during a pressing operation can be realized.
JP 2006-156333 A JP 2003-71956 A

  By the way, the key sheet is configured to illuminate with light from a light source (backlight) provided inside the electronic device so that it can be easily pressed even in a dark place. Also in said patent document 2, the cutout part which shows display elements, such as a character and a symbol, is formed in a decorating sheet, The cutout part is made into the illumination part. However, since the cut surface of the cutout portion is exposed as it is in this decorative sheet, there is a possibility that the cut surface of the cutout portion may be worn or twisted when the pressing operation is repeated.

  The present invention has been made against the background of the prior art as described above. That is, an object of the present invention is to provide a key sheet that is thin, has a soft touch feeling, and is excellent in durability. A further object of the present invention is to provide a key sheet with a novel design that can change the display element between when illuminated by backlight and when not illuminated.

  In order to achieve the above object, the present invention comprises a translucent substrate sheet and a soft feel layer laminated on the surface side of the substrate sheet and having a soft hand feeling. For a key sheet that can be illuminated by light from the side, the soft feel layer has a light-transmitting skin layer with a soft touch and a thickness of 250 μm to 700 μm or 250 μm to 450 μm laminated on the back side of the skin layer. A porous layer, a first decorative portion that is provided between the skin layer and the porous layer and is visible through the skin layer, and provided on the back side of the porous layer, and passes through the skin layer and the porous layer by light from the back side. A key sheet comprising: a visually recognizable second decorating portion.

In the present invention, a soft feel layer is provided on the surface side of the base sheet, and the operation surface is composed of a skin layer of the soft feel layer, so that a soft hand feeling can be given during a pressing operation, and a soft touch feeling can be provided. It is possible to realize a key sheet having the same.
And in a soft feel layer, since a 1st decoration part is provided in the back surface side of an outer skin layer, abrasion of a 1st decoration part can be prevented in the case of pressing operation. Since this 1st decoration part can be visually recognized through a translucent skin layer, it can be used as a highly visible decoration part, and a 1st decoration part is used as a display part which shows display elements, such as a character and a symbol. Thus, the display element can be clearly visually recognized. Further, since the display element is formed by the cutout portion in the related art, a cutout hole exists in the pressing operation portion, and the decorative sheet may be rolled up during the pressing operation. However, in the present invention, a key sheet having no such hole in the pressing operation portion and excellent in durability can be realized.

In the soft feel layer, a porous layer having a thickness of 250 μm to 700 μm is laminated on the back side of the skin layer. Since this porous layer is composed of countless small holes like a sponge and looks cloudy, it is difficult to see through the second decorative portion provided on the opposite side of the porous layer with light illuminated from behind the operator. That is, it is difficult for the operator to visually recognize the second decorative portion provided on the back surface side of the porous layer from the operation surface side through the porous layer when the backlight light source is not emitting light. Therefore, the operator can visually recognize only the 1st decoration part provided in the surface side of the porous layer at the time of non-lighting. On the other hand, when the backlight source emits light, the light that illuminates the second decorative portion from the back side of the porous layer passes through the porous layer and illuminates the first decorative portion. For this reason, the operator can visually recognize the 2nd decoration part which floats with the 1st decoration part at the time of illumination. That is, the decorative design can be changed between non-illuminated and illuminated, and a novel design key sheet can be realized.
If the thickness of the porous layer is less than 250 μm, the second decorative part can be visually recognized even when not illuminated, and if it is thicker than 700 μm, the second decorated part becomes difficult to visually recognize even when illuminated. The decoration design cannot be changed.
If the porous layer is soft, the operation surface of the soft feel layer can be easily depressed by the flexibility of the porous layer, and the soft touch feeling can be further enhanced.

About the said key sheet | seat of this invention, a porous layer can be made into the foam layer of the open cell connected in the thickness direction. “The open-cell foam layer connected in the thickness direction” means, for example, a foam layer having a structure in which bubbles are continuously connected in the thickness direction and appear as vertical holes, as shown in the electron microscope (SEM) photograph of FIG. Say.
For example, in the foamed layer of closed cells as shown in the electron micrograph of FIG. 11, since the substantially spherical bubbles are arranged at random, the transmitted light is easily diffused, and the second decorative portion may become unclear when illuminated. On the other hand, in the open cell foam layer, the transmitted light easily passes through the continuously connected bubble portions. Therefore, if the porous layer is an open-celled foam layer connected in the thickness direction, the transmitted light of the second decorative portion can be easily passed to the surface side during illumination, and the second decorative portion can be visually recognized clearly. Can do. And when a display element is represented by the 2nd decoration part, it is preferable to make it a foam layer of the open cell which connects a porous layer to the thickness direction. Furthermore, if the thickness of the porous layer is 250 μm to 450 μm, a small display element can be clearly seen. This is because if the thickness is less than 250 μm, the second decorative portion can be visually recognized even when not illuminated, and if it is thicker than 450 μm, the second decorative portion becomes difficult to see during illumination.

  About the said key sheet | seat of this invention, the surface of an outer skin layer can be made into an uneven surface. In this way, the friction coefficient of the surface in the skin layer can be reduced, and the surface can be smoothed. Therefore, a soft touch feeling can be enhanced.

  About the said key sheet | seat of this invention, when the back surface of an outer skin layer is an uneven surface, the transparent and soft medium layer which makes the unevenness | corrugation surface small can be provided in this uneven surface. In this way, even if the back surface of the skin layer is an uneven surface, if the height difference of the undulation is small, the first decorative portion can be accurately provided on the back surface side of the skin layer, and this first decorative portion is displayed. If it is a part, a key sheet having a clear display part can be realized. Even when the medium layer is provided, the first decorative portion is not easily seen because the medium layer is transparent, and the soft touch feeling is not impaired because the medium layer is soft.

  About the said key sheet | seat of this invention, a 1st decoration part is a display part which shows display elements, such as a character, a number, and a symbol, and a soft feel layer has a through-hole as a partition line which divides this display part Can be. If it does in this way, backlight will permeate | transmit a translucent base material sheet and will light-emit outside through this through-hole. Therefore, a difference can be provided between the illumination brightness from the display unit and the illumination brightness from the partition line, and a key sheet having a characteristic of illumination can be realized. In addition, it is possible to distinguish at least each display unit by illuminating from the partition line. In addition, the “partition line” that divides the display unit here is a press that consists of the display unit and the background unit in addition to the one that separates one display unit and the other display unit like a partition line that divides adjacent display units. It includes what separates the operation part from other pressing operation parts and parts other than the pressing operation part.

  Providing the partition lines in this way makes it easy to visually recognize the pressing operation part, and makes it difficult to make an erroneous input. Note that both the display portion and the portion other than the display portion can be light-transmitting or either one can be light-shielding. That is, the display unit can be visually recognized if the light transmittance of the display unit and the part other than the display unit is different. Even if the light transmittance is substantially the same, the display portion can be visually recognized if the color tone of the two is made different. The shape of the partition line is a shape that can substantially divide the pressing operation portion, and can be, for example, a shape that surrounds the outer periphery of the pressing operation portion in a frame shape, a shape that indicates a part of the outer periphery of the pressing operation portion, or the like. And since the through-hole was made into the partition line which divides a press operation part, a partition line can be illuminated brightly. Further, the pressing operation portion can be confirmed by tactile sensation by the partition line. Furthermore, since the key sheet is easily bent during the pressing operation, the pressing load can be kept low, and the pressing operability can be improved.

About the said key sheet | seat of this invention, the protection part which coat | covers this side surface can be provided in the side surface of the edge part in a porous layer. In this way, the porous layer is not exposed to the outside, and the durability of the porous layer can be enhanced.
Moreover, if a protection part is provided also in the through-hole as a partition line provided in the soft feel layer, the side surface of the porous layer is not exposed from the through-hole, and the durability of the porous layer can be enhanced.

About the said key sheet | seat of this invention, an EL member can be further provided in the back surface of a base material sheet. If it does in this way, a 2nd decorating part can be illuminated uniformly by surface light emission, and the visibility of the edge in a 2nd decorating part can be improved.
Moreover, a light guide plate can be further provided on the back surface of the base sheet. If it does in this way, the backlight light by light sources, such as LED and EL, can be efficiently transmitted to a key sheet, and illumination brightness can be raised.

  According to the key sheet of the present invention, since a soft feel layer is provided on the surface side of the base sheet, a soft touch feeling can be given during a pressing operation, and a thin key sheet having a soft touch feeling is realized. be able to. Moreover, since the 1st decoration part does not wear at the time of pressing operation and there is no hole in the pressing operation part of a soft feel layer, it can implement | achieve the key sheet excellent in durability. Furthermore, the design can be changed to a design that gives different appearances when not illuminated and when illuminated, and a key sheet with a novel design can be realized.

  Embodiments of the present invention will be described below with reference to the drawings. An example in which the key sheet of the present invention is applied to a mobile phone as an “electronic device” will be described. In addition, duplication description is abbreviate | omitted about the member, material, structure, manufacturing method, and effect which are common in each embodiment.

First Embodiment (FIGS. 1 and 2) :
A key sheet 1 of the first embodiment is shown in FIGS. 1 is a plan view of the key sheet 1, FIG. 2 is a cross-sectional view of the key sheet 1, and FIG. 3 is a plan view of the key sheet 1 when illuminated. The key sheet 1 according to the first embodiment includes a base sheet 2 and a soft feel layer 3, and the soft feel layer 3 includes an outer skin layer 4, a first decorative portion 5, a fixing layer 6, and a porous layer 7. The fixing layer 8 and the second decorative portion 9 are provided in this order from the operation surface (front surface) side.

  The skin layer 4 is a layer which gives a soft hand feeling on the outermost surface, and is formed in a flat sheet shape with a translucent polymer material. As the material of the skin layer 4, a resin or an elastomer excellent in wear resistance, water resistance, and chemical resistance can be used. Examples thereof include polyolefin resins such as polyethylene and polypropylene, polystyrene resins such as polystyrene and styrene-maleic anhydride copolymers, polyurethane resins, polyvinyl chloride resins, and thermoplastic elastomers. In particular, when a polyurethane resin is used, an excellent soft touch feeling can be obtained.

A resin composition containing foamable beads, hollow beads, elastic beads, inorganic materials, or the like in these resins or elastomers forming the skin layer 4 can be used. By adding such beads and inorganic materials, small unevenness can be given to the skin layer 4 and various tactile sensations can be brought about. The expandable beads are those that become hollow beads when heated, and examples of the material include polyurethane, acrylic-urethane copolymer, polystyrene, styrene-isoprene copolymer, and the like. The hollow beads are hollow spheres, and examples of the material thereof include copolymers such as vinylidene chloride and acrylonitrile, and cross-linked acrylic. Elastic beads are resin particles that have the property of elastic recovery when released after being pressurized until their shape changes, such as polyurethane resin, acrylic-urethane resin, polystyrene resin, styrene-isoprene copolymer, etc. Is mentioned. Examples of the inorganic material include silicon dioxide (SiO ₂ ; also referred to as silica and anhydrous silicic acid), hydrous silicic acid (SiO ₂ xH ₂ O), hydrous aluminum silicate (Al ₂ O ₃ 9SiO ₂ xH). ₂ O).
Moreover, various additives, such as coloring agents, such as a pigment and dye, antioxidant, and an ultraviolet absorber, can be mix | blended with the said resin and elastomer.

  The thickness of the skin layer 4 is preferably 5 μm to 200 μm. If the thickness is less than 5 μm, the durability is low and breakage tends to occur. If the thickness exceeds 200 μm, the rigidity increases and the tactile sensation with respect to the operator is deteriorated, making it difficult to express a soft touch feeling.

  The first decorating unit 5 is a coating layer printed on the back surface of the skin layer 4, and has a rectangular shape surrounding the pressing operation unit 10 by separating the display unit 5 a and display unit 5 a representing display elements such as characters and numbers. It is comprised with the partition line 5b. The display unit 5a represents display elements mainly used for calls. As the material of the first decorative portion 5, ink or paint that can be applied to the skin layer 4 can be used.

  The fixing layer 6 is a layer that fixes the skin layer 4 and the porous layer 7 and is formed of a translucent adhesive or pressure-sensitive adhesive. An adhesive film, an adhesive film, a hot melt adhesive, or the like can be used for the fixing layer 6.

The porous layer 7 is an easily dent layer laminated on the back surface side of the skin layer 4 and is formed of a foam having a small compression elastic modulus. And this porous layer 7 is translucent, and since the 2nd decoration part 9 is the display part 9a showing the small display element so that it may mention later, the structure consists of a foam layer of the open cell connected in the thickness direction. The thickness is 250 μm to 450 μm. If the thickness is less than 250 μm, the second decorative portion 9 can be visually recognized even when not illuminated, and if it is thicker than 450 μm, the second decorated portion 9 becomes difficult to see when illuminated. The material of the porous layer 7 is a resin or elastomer that can be foam-molded. Like the material of the skin layer 4, for example, a polyolefin resin such as polyethylene or polypropylene, or a polystyrene resin such as polystyrene or a styrene-maleic anhydride copolymer. Examples thereof include resins, polyurethane resins, polyvinyl chloride resins, and thermoplastic elastomers.
In addition, when the 2nd decoration part 9 represents a pattern and a character unlike this embodiment, even if the 2nd decoration part 9 which floats at the time of illumination is a little unclear, a design effect can be exhibited. Therefore, the configuration of the porous layer can be a closed-cell foamed layer, and the thickness of the porous layer can be 250 μm to 700 μm.

  The fixing layer 8 is a layer for fixing the base sheet 2 and the porous layer 7 and is formed of a translucent adhesive or pressure-sensitive adhesive. Similar to the fixing layer 6, an adhesive film, an adhesive film, a hot melt adhesive, or the like can be used for the fixing layer 8.

  The 2nd decoration part 9 consists of an application layer printed and formed on the surface of the base material sheet 2, and it is as the display part 9a showing display elements, such as a character and a number. The display section 9a represents display elements mainly used for mail. The material of the 2nd decorating part 9 can use the ink and coating material which can be coated with respect to the base material sheet 2. FIG.

  The base material sheet 2 is a member having a function of imparting the formability of the key sheet 1 and is formed of a light-transmitting resin. In addition, when a pusher is provided on the back surface of the base sheet 2, the pressing operability can be improved. For the base sheet 2, a translucent thermoplastic resin or a thermosetting resin is used. For example, acrylic resin, styrene resin, polyester resin, polyolefin resin, silicone resin, epoxy resin, urethane resin, and the like can be given. As for the thickness of the base material sheet 2, 100 micrometers-500 micrometers are preferable. If the thickness is less than 100 μm, the strength is small, and there is a risk of breakage in post-processing. Further, the rigidity is small and it is difficult to maintain the shape of the key sheet 1. When the thickness exceeds 500 μm, the rigidity is large and it is difficult to bend. Therefore, in the case of a key sheet that performs a pressing operation, the pressing load becomes high and the operability deteriorates.

  An example of the manufacturing method of the key sheet 1 will be described. First, after the first decorative portion 5 is printed on the back surface of the skin layer 4, the fixing layer 6 is printed on the entire back surface of the skin layer 4. Then, the fixing layer 6 is laminated on the surface of the porous layer 7 and heated and pressed from the skin layer 4 side with a thermocompression bonding machine or the like, and the skin layer 4 and the porous layer 7 are fixed using the fixing layer 6 as a hot melt adhesive layer. . On the other hand, after the second decorative portion 9 is printed on the surface of the base sheet 2, the fixing layer 8 is printed on the entire surface of the base sheet 2. Finally, the fixing layer 8 is laminated on the back surface of the porous layer 7, heated and pressed from the base sheet 2 side with a thermocompression bonding machine or the like, and the fixing layer 8 is used as a hot melt adhesive layer. To fix. Thus, the key sheet 1 is manufactured.

  According to the key sheet 1, since the operation surface is constituted by the skin layer 4 of the soft feel layer 3, it is possible to give a soft hand feeling during the pressing operation. Furthermore, since the porous layer 7 is formed of a foam having a small compression elastic modulus, the operation surface of the soft feel layer 3 can be easily depressed by the flexibility of the porous layer 7, and the key sheet 1 having a soft touch feeling is realized. be able to.

  And since the display part 5a and the partition line 5b of the 1st decoration part 5 are provided in the back surface side of the skin layer 4, the wear of the 1st decoration part 5 can be prevented in the case of pressing operation. Furthermore, since this 1st decoration part 5 is visually recognizable through the translucent skin layer 4, it can be set as the highly visible display part 5a and the partition line 5b, and can visually recognize a display element and the press operation part 10 clearly. can do.

  Since the porous layer is an open-celled foam layer connected in the thickness direction and has a thickness of 250 μm to 450 μm, the display portion 5 a of the first decorative portion 5 provided on the surface side of the porous layer 7 is not illuminated. And the partition line 5b can be visually recognized, and the pressing operation unit 10 can represent display elements mainly used for calls (FIG. 1). At the time of illumination, the second decorating part 9 that floats together with the first decorating part 5 can be visually recognized, and the pressing operation part 10 can clearly represent small display elements mainly used for e-mail (FIG. 3). That is, the decoration design can be changed between the non-illumination and the illumination, and the key sheet 1 having a novel design can be realized.

Modification of the first embodiment :
In the key sheet 1 of the first embodiment, the display element 5a and the partition line 5b that are mainly used for calls in the first decoration unit 5 are represented, and the display that is mainly used for mail in the second decoration unit 9 Although the example which represents the display part 9a of an element was shown, as a modification, all the display elements can be represented by the 1st decoration part, and a partition line can be represented by the 2nd decoration part. In this way, since all the display elements are provided on the back surface of the skin layer 4, fine display elements can be clearly seen, and the partition lines can be raised only during illumination. As another modified example, all display elements and partition lines can be represented by the first decoration portion, and patterns such as patterns, characters, logo marks, and the like can be represented by the second decoration portion. Furthermore, in the case of this modification, the structure of the porous layer can be a closed cell foam layer, and the thickness of the porous layer can be 250 μm to 700 μm.

Second Embodiment [FIGS. 4 to 6] :
A key sheet 11 according to the second embodiment is shown in FIGS. 4 is a plan view of the key sheet 11, FIG. 5 is a sectional view of the key sheet 11, and FIG. 6 is a plan view of the key sheet 11 when illuminated. The key sheet 11 of the second embodiment is different from the key sheet 1 of the first embodiment in the configuration of the soft feel layer 12. That is, the soft feel layer 12 includes a skin layer 13, a first decorative portion 14, a fixing layer 6, a porous layer 7, a fixing layer 8, and a second decorative portion 15, and a medium layer 16 on the back surface of the skin layer 13. Is given. The remaining configuration is the same as that of the key sheet 1.

  The skin layer 13 is formed in a concavo-convex shape in which the front surface and the back surface are inclined surfaces, and the concavo-convex pattern represents a striped pattern in plan view. And the depth of the recessed part in this uneven | corrugated shape is 5 micrometers-500 micrometers. If the depth is less than 5 μm, it is difficult to visually see the uneven pattern, and the first decorative layer is formed as a substantially flat layer, and the color of the first decorative layer hardly changes. When it is deeper than 500 μm, it is difficult to form the first decorative layer with respect to the concave and convex portions.

  The 1st decoration part 14 represents the display part 14a of a display element, and the 2nd decoration part 15 represents the rectangular partition line 15a.

  The medium layer 16 is a layer that is printed on the back surface of the skin layer 13 and reduces the height difference of the unevenness formed on the back surface of the skin layer 13. The medium layer 16 is formed of a transparent and soft polymer material with a non-uniform layer thickness. That is, the film thickness of the medium layer 16 is such that the vicinity of the bottom of the concave portion of the skin layer 13 is thick, gradually decreases from the concave portion toward the convex portion, and the film thickness covering the convex portion is the thinnest. As described above, the back surface of the medium layer 16 is formed in a concavo-convex shape. However, since the layer thickness is as described above, the difference in level of undulation on the back surface of the medium layer 16 is the difference in level of undulation on the back surface of the skin layer 13. Smaller than. The material of the medium layer 16 can be ink or paint that can be applied to the skin layer 13.

  In manufacturing the key sheet 11, first, an uneven shape is transferred and formed on the front and back surfaces of the skin layer 13 using a release sheet or a mold. After the medium layer 16 is printed on the back surface of the skin layer 13, the first decorative portion 14 and the fixing layer 6 are printed. Then, the skin layer 13 and the porous layer 7 are fixed by using the fixing layer 6 as a hot melt adhesive layer. On the other hand, the 2nd decorating part 15 and the adhering layer 8 are printed and formed on the surface of the base material sheet 2. Finally, the base sheet 2 and the porous layer 7 are fixed using the fixing layer 8 as a hot melt adhesive layer. In this way, the key sheet 11 is obtained.

  According to the key sheet 11, even if the back surface of the skin layer 13 is an uneven surface, the medium layer 16 reduces the level difference of the undulations, so the first decorating portion 14 can be accurately provided. A clear display portion 14a can be realized by the 1 decoration portion 14. Even when the medium layer 16 is provided, the first decorative portion 14 is not easily seen because the medium layer 16 is transparent, and the soft touch feeling is not impaired because the medium layer 16 is soft.

  Since the display unit 14a of the display element is represented by the first decorating unit 14 and the partition line 15a is represented by the second decorating unit 15, the fine display unit 14a can be clearly seen when not illuminated (FIG. 4). ) When illuminated, the partition line 15a surrounding the display unit 14a can be raised (FIG. 6). Therefore, the pressing operation unit 10 can be easily visually recognized at the time of illumination, and erroneous input can be made difficult to occur.

  Since the surface of the skin layer 13 is an uneven surface, the friction coefficient of the surface of the skin layer 13 can be reduced, and the surface can be smoothed. Therefore, a soft touch feeling can be enhanced.

Third Embodiment (FIG. 7) :
A key sheet 17 of the third embodiment is shown in FIG. FIG. 7 shows a cross-sectional view of the key sheet 17. The key sheet 17 of the third embodiment differs from the key sheet 1 of the first embodiment in the configuration of the soft feel layer 18. That is, in this embodiment, the partition line is not represented by the first decorative portion, but is a through hole 19 that penetrates the thickness of the soft feel layer 18. Such a soft feel layer 18 includes a skin layer 20, a first decorative portion 21, a fixing layer 22, a porous layer 23, a fixing layer 24, and a second decorative portion 9 in this order from the surface side. The remaining configuration is the same as that of the key sheet 1.

  As with the key sheet 1 of the first embodiment, the key sheet 17 is manufactured by laminating the soft feel layer 18 without the through holes 19 and the base sheet 2. Thereafter, a blade is applied from above the skin layer 20 to form the through-hole 19 that penetrates the skin layer 20, the fixing layer 22, the porous layer 23, and the fixing layer 24. In this way, the key sheet 17 is obtained.

  According to the key sheet 17, since the through hole 19 as the partition line is provided, the pressing operation unit 10 can be confirmed by the through hole 19 even with a tactile sensation. Furthermore, since the key sheet 17 is easily bent during the pressing operation, the pressing load can be kept low, and the pressing operability can be improved.

  At the time of illumination, the backlight light passes through the translucent substrate sheet 2 and emits light to the outside through the through hole 19. Therefore, a difference can be provided between the illumination brightness from the pressing operation unit 10 and the illumination brightness from the through hole 19, and the key sheet 17 having a characteristic of illumination can be realized.

Fourth Embodiment (FIG. 8) :
A key sheet 25 of the fourth embodiment is shown in FIG. FIG. 8 shows a cross-sectional view of the key sheet 25. The key sheet 25 of the fourth embodiment is different from the key sheet 17 of the third embodiment in the configuration of the soft feel layer 26. In other words, in the present embodiment, the edge portion of the skin layer 27 extends, and a protective portion 26 a that covers the side surfaces of the edge portions of the fixing layer 22, the porous layer 23, and the fixing layer 24 is provided. The remaining configuration is the same as that of the key sheet 17.

  The key sheet 25 is manufactured by laminating the soft feel layer 26 without the through hole 19 and the base sheet 2 in the same manner as the key sheet 17 of the third embodiment. Thereafter, the soft feel layer 26 is pressed from the skin layer 27 side using the thermocompression bonding method or the ultrasonic fusion method, and the fixing layer 22, the porous layer 23, and the through hole 19 of the fixing layer 24 are formed. Is covered with a protective portion 27 a of the skin layer 27. In this way, the key sheet 25 is obtained.

  According to the key sheet 25, since the protection part 27a which covers the side surface of the edge part in the porous layer 23 is provided, the porous layer 23 is not exposed to the outside, and the durability of the porous layer 23 can be improved.

Fifth embodiment (FIG. 9) :
A key sheet 28 of the fifth embodiment is shown in FIG. FIG. 9 shows a cross-sectional view of the key sheet 28. The key sheet 28 of the fifth embodiment is different from the key sheet 17 of the third embodiment in that the EL member 29 is provided on the back surface of the base sheet 2. The remaining configuration is the same as that of the key sheet 17.

  As with the key sheet 17 of the third embodiment, the key sheet 28 is manufactured after forming a key sheet including the base sheet 2 and the soft feel layer 18, and then placing the EL member 29 on the back surface of the base sheet 2. Fix with an external translucent adhesive. Thus, the key sheet 28 is obtained. In the present embodiment, the EL member 29 is fixed to the back surface of the base sheet 2 with an adhesive, but the EL member 29 can be directly printed on the back surface of the base sheet 2.

  According to the key sheet 28, since the EL member 29 is provided on the back surface of the base sheet 2, the second decorative portion 9 can be illuminated by surface light emission, and the visibility of the edge in the second decorative portion 9 is enhanced. be able to.

Modification of the fifth embodiment :
In the key sheet 28 of the fifth embodiment, the example in which the EL member 29 is provided on the back surface of the base sheet 2 in the key sheet 17 of the third embodiment is shown, but as a modification, the key sheets 1, 11, 11, The EL member 29 can be provided on the back surface of 25.

  Next, the present invention will be described in more detail by showing a specific example of manufacturing a key sheet.

1. Key sheet manufacturing :

Sample 1 :
The first decorative part (5) representing the display part (5a) and the partition line (5b) is printed on the back surface of the skin layer (4) made of a translucent urethane resin with a thickness of 50 μm using vinyl acetate ink. did. Thereafter, an adhesive layer (6) made of a hot melt adhesive is printed on the entire back surface of the skin layer (4), and the adhesive layer (6) has a thickness of 250 μm and is connected to the open cell porous layer (7 ), And heated and pressed from the skin layer (4) side with a thermocompression bonding machine or the like to fix the skin layer (4) and the porous layer (7). On the other hand, the second decorative part (9) representing the display part (9a) is printed with vinyl acetate ink on the surface of the base sheet (2) made of a light-transmitting polyethylene terephthalate (PET) film having a thickness of 188 μm. did. Thereafter, a fixing layer (8) made of a hot melt adhesive is printed on the entire surface of the base sheet (2), and this fixing layer (8) is laminated on the back surface of the porous layer (7). The base sheet (2) and the porous layer (7) were fixed by heating and pressing from the base sheet (2) side, etc. to produce a key sheet (1). This was designated as Sample 1.

Sample 2 :
A key sheet (1) was produced in the same manner as sample 1 using a porous layer (7) of open cells connected in the thickness direction with a thickness of 450 μm, and designated as sample 2.

Sample 3 :
The first decorative part (5) representing the display part (5a) and the dividing line (5b) is printed on the back side of the same skin layer (4) as in sample 1, and printed on the entire back side of the skin layer (4). The formed fixing layer (6) was fixed to the surface of the open-celled porous layer (7) having a thickness of 500 μm and connected in the thickness direction. In addition, the second decorative portion (9) representing a lattice pattern is printed on the surface of the base material sheet (2) similar to the sample 1, and the fixing layer (printed on the entire surface of the base material sheet (2)). In 8), the key sheet (1) was produced by adhering to the back surface of the porous layer (7). This was designated as Sample 3.

Sample 4 :
A key sheet (1) was produced in the same manner as sample 3 using a porous layer (7) of open cells connected in the thickness direction with a thickness of 700 μm, and it was designated as sample 4.

Sample 5 :
A key sheet was produced in the same manner as Sample 3 by using an open-cell porous layer having a thickness of 900 μm and connected in the thickness direction.

Sample 6 :
A key sheet (1) was produced in the same manner as in sample 3 using a porous layer (7) having a thickness of 285 μm and closed cells, and designated as sample 6.

Sample 7 :
A key sheet (1) was produced in the same manner as Sample 3 using a porous layer (7) having a thickness of 390 μm and closed cells, and Sample 7 was obtained.

Sample 8 :
A key sheet (1) was produced in the same manner as Sample 3 using a porous layer (7) having a thickness of 550 μm and closed cells, and Sample 8 was obtained.

Sample 9 :
A key sheet was produced in the same manner as in Sample 3 using a porous layer having a thickness of 190 μm and closed cells, and Sample 9 was obtained.

2. Key sheet evaluation :

  About said sample 1-sample 9, the visibility of the 1st decoration part (5) and the 2nd decoration part (9) at the time of non-lighting and the time of lighting was evaluated.

  “Visibility evaluation”: A sample is placed in the center of the upper surface of a light table incorporating a standard light source D65 (JIS Z 8720), and the upper surface other than this sample is covered with a light-shielding masking sheet. The visibility of the second decorative portion (9) was confirmed when the light source was not emitting light (when not illuminated) and when it was emitting light (when illuminated). The results are shown in Tables 1 and 2. “Unidentifiable” in the table means that 8 or more out of 10 evaluators could not confirm the second decoration part (9), and “confirmable” means 10 evaluators It means that 8 or more of them were able to confirm the second decoration part (9). And "x" does not exhibit the effect of the present invention, and the second decorative part (9) could be confirmed during non-lighting and the second decorative part (9) could not be confirmed during lighting. Means that. “◯” and “◎” show the effects of the present invention. In particular, “◎” means that the second decorative portion (9) can be clearly confirmed during illumination.

As shown in Table 1, sample 1 and sample 2 can be confirmed only by the display part (5a) and the first decoration part (5) of the partition line (5b) when not illuminated, and when illuminated, the display part is backlit. (9a) emerged and both the first decorative part (5) and the second decorative part (9) could be clearly confirmed. Moreover, in the sample 3 and the sample 4, only the display part (5a) and the first decoration part (5) of the partition line (5b) can be confirmed at the time of non-lighting, and the second decoration of the lattice pattern by the backlight light at the time of lighting. The part (9) emerged, and a lattice pattern could be confirmed behind the display part (5a) and the partition line (5b).
Even if the sample 5 had a structure of open cells connected in the thickness direction in which the porous layer was easily illuminated, the second decorative portion (9) as the display portion (9a) could not be confirmed during illumination.

As shown in Table 2, in samples 6 to 8, only the display part (5a) and the first decoration part (5) of the partition line (5b) can be confirmed when not illuminated, and when illuminated, a lattice pattern is formed by backlight. The second decorating part (9) emerged, and a lattice pattern could be confirmed behind the display part (5a) and the partition line (5b). The lattice pattern that emerged from the backlight was slightly unclear.
In the sample 9, even when the porous layer has a structure of closed cells that easily diffuses light, a lattice pattern can be confirmed at the time of non-lighting.

The top view which shows the key sheet of 1st Embodiment. FIG. 3 is a sectional view taken along line SA-SA in FIG. 1. The top view which shows the time of illumination in the key sheet of 1st Embodiment. The top view which shows the key sheet of 2nd Embodiment. SB-SB sectional view taken on the line of FIG. The top view which shows the time of illumination in the key sheet | seat of 2nd Embodiment. FIG. 2 is a cross-sectional view corresponding to FIG. 2 illustrating a key sheet according to a third embodiment. Sectional drawing equivalent to FIG. 2 which shows the key sheet | seat of 4th Embodiment. FIG. 6 is a cross-sectional view corresponding to FIG. 2 illustrating a key sheet according to a fifth embodiment. The microscope picture figure which shows the porous layer which consists of a foam layer of an open cell. The microscope picture figure which shows the porous layer which consists of a foam layer of a closed cell.

Explanation of symbols

1 Key sheet (first embodiment)
DESCRIPTION OF SYMBOLS 2 Base material sheet 3 Soft feel layer 4 Skin layer 5 1st decoration part 5a Display part 5b Partition line 6 Adhesion layer 7 Porous layer 8 Adhesion layer 9 2nd decoration part 9a Display part 10 Press operation part 11 Key sheet (1st Second embodiment)
12 Soft Feel Layer 13 Skin Layer 14 First Decorating Part 14a Display Part 15 Second Decorating Part 15a Partition Line 16 Medium Layer 17 Key Sheet (Third Embodiment)
18 Soft Feel Layer 19 Through Hole 20 Skin Layer 21 First Decorating Part 22 Adhesive Layer 23 Porous Layer 24 Adhesive Layer 25 Key Sheet (Fourth Embodiment)
26 Soft Feel Layer 27 Skin Layer 27a Protection Unit 28 Key Sheet (Fifth Embodiment)
29 EL member

Claims (6)

A translucent base material sheet, and a soft feel layer laminated on the surface side of the base material sheet and having a soft hand feeling,
In the key sheet that can be illuminated by light from the back side of the base sheet,
Soft feel layer
A translucent skin layer with a soft touch;
A porous layer having a thickness of 250 μm to 700 μm laminated on the back side of the skin layer;
A first decorative portion provided between the skin layer and the porous layer and visible through the skin layer;
A key sheet comprising: a second decorative portion that is provided on the back surface side of the porous layer and is visible through the skin layer and the porous layer by light from the back surface side.   The key sheet according to claim 1, wherein the porous layer has a thickness of 250 μm to 450 μm.   The key sheet according to claim 1, wherein the porous layer is an open-cell foamed layer connected in the thickness direction. The back surface of the skin layer is an uneven surface,
The key sheet according to any one of claims 1 to 3, wherein a transparent and soft medium layer is provided on the concavo-convex surface to reduce a difference in level of the undulations. The first decoration unit is a display unit showing display elements such as letters, numbers, symbols,
The key sheet according to any one of claims 1 to 4, wherein the soft feel layer has a through hole as a partition line separating the display portion.   The key sheet according to any one of claims 1 to 5, wherein a protective portion that covers the side surface is provided on a side surface of the edge portion of the porous layer.