JP6518962B2 - Decorative illumination member - Google Patents

Description

  The present invention relates to a decorative illumination member having an illumination display unit illuminated by the light of an internal light source. This decorative illumination member can be used as, for example, an input operation member (key pad, touch panel, etc.) mounted on various electronic devices such as a portable information terminal device, an imaging device, and an in-vehicle electrical device.

  The input operation member mounted on the above-described electronic device is required to be further miniaturized and thinned along with the electronic device. Therefore, for example, in an electronic device that illuminates an LED as its internal light source, the internal light source and the input operation member tend to be disposed closer to each other. And this is one of the causes of the generation of the "uneven illumination" which is undesirable as the illumination quality in the input operation member as the decorative illumination member. This will be specifically described using a keypad as a decorative illumination member.

  Conventionally, a key pad having a structure in which a hard resin key top is attached to a base sheet made of silicone rubber is known. However, under the influence of thinning of electronic devices, the use of a base sheet made of silicone rubber, which has a limit to thinning, has been abolished, and a configuration using a base sheet made of a resin film is increasing. A key top is provided on the surface, and on the back surface of the base sheet, a frustum-shaped pusher made of transparent hard resin for pressing a metal dome provided on the substrate is provided. The pusher is provided on the pusher sheet. The presser sheet is obtained by forming the presser on a transparent resin film.

  Therefore, this keypad is thinly configured by the base sheet on which the key top is provided and the pusher sheet. A decorative layer is printed on the base sheet of the keypad. The decorative layer is provided with a "lighting display section" having display elements representing characters, numbers, symbols or figures and its background, and is illuminated by the light of an LED mounted on a substrate immediately below or in the vicinity thereof. It is supposed to be. Such keypads have the advantage of being simple in structure and inexpensive.

JP 2012-164450 A

  However, with the above-mentioned keypad, there is a problem that when illuminated, light entering the side of a transparent hard resin truncated cone-shaped pusher appears bright as an appearance of the keypad as ring-shaped light. . The ring-like light is responsible for the "uneven illumination" which interferes with the desired uniform illumination in the illuminated display and should therefore be as unobtrusive as possible.

  As means for concealing ring-shaped light, for example, it is conceivable to increase the thickness of the decorative layer which is a printing layer. It is possible to conceal ring-like light by printing the decorative layer in multiple layers. However, as the printing is performed in multiple layers, the light of the internal light source is more difficult to pass, and the illumination of the decorative layer is dimmed as a whole. As a result, there is a problem that the contrast of the illumination display unit is difficult to be obtained, and the visibility is rather deteriorated. This problem also limits the choice of the illumination display scheme as follows.

  That is, there are two types of illumination display of the illumination display unit, “surface illumination” and “character illumination”. “Area lighting” is a method of forming a display element of characters, numbers, symbols or figures and its background portion with an opaque printing layer, and lighting the background portion around the display element. "Character illumination" is a system which forms as an opaque printing layer which has those display elements as a blank shape, and illuminates the display element without the printing layer. Of these, “surface illumination” is a preferable illumination method that can illuminate the entire illumination display section brightly to improve visibility, and the display element is characterized by being easily visible from the contrast with the background section to be illuminated. There is. However, this "surface illumination" has the problem that the above-mentioned ring-like light is visible in the display element and the surrounding background portion, and as a method of concealing it, it is effective in addition to the multi-layering of the printing layer in which the illumination display portion becomes dim Because there was no remedy, in the end "text illumination", which can easily hide ring-shaped light, has been widely used. Because "character illumination" illuminates the display element and shields the periphery, so the illumination area is narrow, so ring light is less noticeable, and the position of the character is adjusted, above the ring light. Because it was possible to place an opaque background. As described above, the ring-shaped light by the pusher is also a great restriction on the choice of the illumination method of the keypad.

  In the above, although the defect of the ring-shaped light by the pusher of the keypad has been described, it is understood that even the uneven portion like the pusher may cause the "irregular illumination" in the illumination display portion. There is.

  The present invention is made on the background of the prior art as described above. The object of the present invention is to suppress the uneven illumination caused in the illumination display unit due to the inner shape of a decorated illumination member such as a keypad having an illumination display unit.

  In order to achieve the above object, the present invention provides the following decorative illumination member.

  The present invention relates to a decorative illumination member having an illumination display portion illuminated by the light of an internal light source, a translucent exterior member provided with a decoration layer having the illumination display portion, and an upper surface disposed on the exterior member side And a translucent interior member having a lower surface disposed on the side of the internal light source and having an uneven surface portion at a position below the illumination display portion on the lower surface, the surface of the uneven surface portion being a fine uneven surface It features.

  The uneven surface portion of the interior member corresponds to a pusher that generates the ring-shaped light described above, and light entering the side surface of the uneven surface portion may cause the light of the side shape to appear bright on the appearance of the exterior member. is there. However, in the present invention, the fine uneven surface is provided on the surface of the uneven surface including the side surface, and this blurs the light of the side shape which looks bright in the appearance of the exterior member. Therefore, according to the decorated illumination member of the present invention, the occurrence of uneven illumination in the illumination display unit can be suppressed and illumination can be performed uniformly. As a result, the entire thickness of the decorative illumination member can be reduced, and the uneven surface portion of the interior member can be disposed close to the internal light source, which can also contribute to the reduction in thickness of the electronic device provided with the decorative illumination member . Also, even if area illumination is adopted as the illumination method, there is no problem with the prior art in which the contrast is reduced due to thinning as in the multi-layered printing layer, and there is no difference between the illuminated part and the non-illuminated part (display element). It is possible to realize the improvement of the visibility by the high contrast.

  A resin layer containing a light diffusive filler is provided below the light emitting display.

  According to the resin layer containing the light diffusive filler, the light of the side surface shape of the uneven surface portion diffused by the above-described fine uneven surface is further blurred by being repeatedly reflected and refracted inside the resin layer and further diffused. be able to. Therefore, it is possible to realize uniform illumination by suppressing the occurrence of uneven illumination in the illumination display unit.

  In the present invention, the transmittance of the uneven surface portion is higher than the transmittance of the resin layer.

  By making the transmittance of the uneven surface portion higher than the transmittance of the resin layer, brightness can be maintained in the stage of letting light diffused on the fine uneven surface enter the uneven surface portion, and light emitted from the uneven surface portion By spreading the light widely in the resin layer having a low transmittance, it is possible to effectively suppress the occurrence of the uneven lighting by the diffusion without largely reducing the illumination luminance in the illumination display portion.

  The resin layer can be provided on the surface of the interior member facing the exterior member or on the surface of the exterior member facing the interior member.

  Although the resin layer exerts the light diffusion effect regardless of the provision of the resin layer, it is possible to further suppress the uneven illumination of the illumination display portion on the surface of the interior member facing the exterior member. This is because, in addition to the formation of a gap with the exterior member, the distance to the illumination display unit is also large, and these effectively work on the blurring effect.

  A gap made of an air layer can be provided between the exterior member and the interior member.

  According to this, it is possible to diffuse the light on the opposing surfaces of the interior member and the exterior member and to reduce the uneven illumination.

  A translucent adhesive may be provided between the exterior member and the interior member to stick them.

  According to this, the light can be diffused also by the light-transmissive adhesive layer to reduce the uneven illumination, and the exterior member and the interior member are integrated, so that the handling property at the time of assembling to the electronic device is good.

  More specifically, the decorative illumination member of the present invention as described above can be realized as an input operation member. More specifically, the exterior member is an input operation sheet made of a resin film having a display layer of characters, numbers, symbols or figures as the light-emitting display portion and a decorative layer forming a background portion thereof, and the interior member is It can be comprised as what is a presser sheet | seat which consists of a resin film which has a presser as said uneven surface part. That is, it can be configured as a keypad.

  More specifically, the decorative illumination member of the present invention, more specifically, the outer member is a resin molding having a decorative layer in which a display element of characters, numbers, symbols or figures as the illumination display portion and its background portion are formed. It is an outer side molded object which consists of a body, and an interior member can be comprised as an inner side molded object which consists of a resin molded object which has an uneven part as said uneven | corrugated surface part. That is, it can be configured as a decorated molded body.

  According to the decorative illumination member of the present invention, the occurrence of uneven illumination in the illumination display unit can be suppressed and illumination can be performed uniformly. For this reason, the uneven surface portion of the interior member can be disposed in proximity to the internal light source, and the thickness of the decorated illumination member can be reduced as a whole, which can also contribute to the reduction in thickness of the electronic device provided with the decorated illumination member.

  According to the decorative illumination member of the present invention, even if the surface illumination is adopted as the illumination method, the conventional problem in which the light is dim as in the case of multilayering of the printing layer and the contrast is lowered does not occur. That is, it is possible to realize the improvement of the visibility due to the high contrast between the illuminated background portion and the non-illuminated display element in the illuminated display portion. Therefore, with the decorative illumination member of the present invention, it is possible to realize well-lighted, well-viewed illumination which can illuminate the entire illumination display section brightly as an illumination method even though it is thin.

The front view of the keypad of 1st Embodiment. The SA-SA sectional view taken on the line of FIG. The SB section enlarged sectional view of FIG. FIG. 4 is an enlarged cross-sectional view around the presser in FIG. 3; The perspective view of the decoration molding of a 2nd embodiment. The front view of the decorating molded object of FIG. 6. SC-SC sectional view taken on the line of FIG. FIG. 8 is an enlarged view of a section SD of FIG. 7; 4 is a cross-sectional view corresponding to FIG. 3 showing the configuration of the keypad of Experimental Example 1, and (a) to (g) are cross-sectional views of Samples 1 to 7, respectively. Explanatory drawing which shows the test method of Experimental example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The description of the materials, configurations, functions, manufacturing methods and the like common to the embodiments will be omitted.

First Embodiment (FIGS. 1 to 4): Embodiment of Keypad

  In the first embodiment, an embodiment as a keypad 1 will be described as an example of a decorative illumination member. In the following description of the keypad 1, “upper surface”, “lower surface”, “front surface” and “back surface” represent the surface on the printed board P side of the member to be described as “bottom surface” or “back surface”, respectively. The surface side is expressed as "upper surface". Moreover, when it describes as a "surface", the predetermined | prescribed external surface including an upper surface and a lower surface shall be shown. Note that these expressions do not limit the usage method, installation method, and the like of the keypad 1.

  The keypad 1 is a sheet-like input operation member including a key sheet 2 as an "exterior member" and a pusher sheet 3 as an "interior member". The key sheet 2 and the presser sheet 3 are fixed by a double-sided tape 4 provided at the end of the keypad 1.

  The key sheet 2 includes a base sheet 5. A plurality of key tops 6 are disposed on the upper surface 5a, and a decorative layer 7 is formed on the lower surface 5b. The presser sheet 3 is also provided with a base sheet 8, a resin layer 9 including a light diffusing filler is formed on the upper surface 8a, and a presser 10 corresponding to each key top 6 is formed on the lower surface 8b. It is formed. The presser 10 corresponds to the "concave / convex surface portion" of the present invention. And the surface of this presser 10 is formed as the fine concavo-convex surface 10a.

  The base sheet 5 of the key sheet 2 and the base sheet 8 of the presser sheet 3 can be made of the following materials.

  The base sheet 5 is a base material of the key sheet 2 and is formed in a rectangular shape in plan view. Further, the base sheet 8 is a base material of the presser sheet 3 and is formed in a rectangular shape in a plan view as the base sheet 5 is. The base sheets 5 and 8 are bent and deformed when the keypad 1 is pressed, and have flexibility to press the contact switch P1 such as a metal dome of the printed circuit board P provided on the back surface side of the keypad 1. Have. Such base sheets 5 and 8 are flat pieces. The thickness is preferably 50 μm to 300 μm, respectively, in order to make the keypad 1 thinner. The material of the base sheets 5 and 8 is preferably an inexpensive and versatile synthetic resin film. For example, polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polycarbonate (PC) film, polymethyl methacrylate (PMMA) film, polyamide (PA) film, polyurethane (PU) film, acrylonitrile-butadiene-styrene copolymer A combined (ABS) film, a polypropylene (PP) film, a polyethylene (PE) film, a triacetyl cellulose (TAC) film or the like, or a film obtained by alloying or blending them can be used. In addition to synthetic resin films, woven fabrics, non-woven fabrics and the like can be mentioned.

  On the upper surface 5a or the lower surface 5b of the base sheet 5, there is formed a decorative layer 7 representing a display element 7a representing characters, numbers, symbols or figures and its background portion 7b. In the present embodiment, as shown in FIGS. 2 and 3, the decorative layer 7 is provided on the lower surface 5 b of the base sheet 5. The decorative layer 7 can be provided by printing, painting, transfer or the like, and is provided as a printing layer by screen printing in the present embodiment. Specifically, the decorative layer 7 is configured of, for example, a black print layer which is the display element 7a and a white print layer which is the background portion 7b. In the present embodiment, the illumination method by “surface illumination” is adopted by the decorative layer 7. That is, "area illumination" is a preferable illumination method capable of illuminating the entire illumination display unit 7c brightly to improve visibility, and the display element 7a (black) which is not illuminated by the contrast with the background unit 7b (white) to be illuminated. It is easy to see the

  The illumination display unit 7c can be set variously according to the design of the keypad 1 and the illumination method. In the present embodiment, since the entire surface of the keypad 1 is designed to be illuminated, the illumination display unit 7 c is the entire surface of the keypad 1. Besides, for example, only the portion of the lower surface 5 b of the base sheet 5 corresponding to the key top 6 may be set as the illumination display portion to form the decorative layer 7. In this case, a light shielding layer may be provided as a part of the decorative layer 7 in a portion which is not set as the illumination display portion.

  The key top 6 is a member serving as a pressing operation portion of the keypad 1 and is fixed to the operation surface side of the base sheet 5. The material of the key top 6 is preferably transparent in order to enhance the visibility of the decorative layer 7, and a thermoplastic resin or a reaction curable resin is used. For example, polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, acrylonitrile styrene (AS) resin, acrylonitrile butadiene styrene (ABS) resin, their alloy resin etc. can be mentioned. In addition, as an example of the thermosetting resin, a reaction curable resin composition (hereinafter referred to as "liquid curable resin") which is liquid at normal temperature and contains a polymer, an oligomer, a monomer, a polymerization initiator, an additive and the like. Can be used. An active energy ray curing type or a thermosetting type can be used as the reaction form of the liquid curing type resin. Among them, the active energy ray curing type is preferable from the viewpoint of productivity and cost. As the active energy ray, visible light, ultraviolet light, X-ray, electron beam and the like can be mentioned, but it is preferable to use ultraviolet light which is an inexpensive apparatus and whose curing process is easy, and UV curable resin is preferable for liquid curable resin. It is. Examples of the ultraviolet curable resin include acrylate resins such as polyester (meth) acrylate, urethane (meth) acrylate, silicone (meth) acrylate and epoxy (meth) acrylate. The key top 6 need not necessarily be fixed to the pressing operation portion, and a sheet-like key sheet having a flat surface without unevenness can also be formed. Also, the key tops may be separated one by one.

  A presser 10 is provided on the lower surface 8 b of the base sheet 8 of the presser sheet 3. A fine uneven surface 10 a is formed on the entire surface of the presser 10. The fine uneven surface 10a is also a light diffusion layer having a function of refracting and irregularly reflecting light emitted from the LED P2 provided on the printed circuit board P as an internal light source.

  The transmittance of the fine uneven surface 10a is preferably 0.5% or more. If the transmittance is less than 0.5%, the brightness of the illumination may be too low. The transmittance is more preferably 1.0% or more. If the transmittance is 1.0% or more, it can be illuminated sufficiently brightly. On the other hand, the upper limit of the transmittance is not particularly limited, but if it exceeds 20%, the light diffusivity becomes insufficient and there is a possibility that uniform illumination can not be performed. Moreover, although it is especially preferable that the press 10 containing the fine uneven | corrugated surface 10a is colorless, it can also be made non-colorless. In the present invention, the transmittance is the parallel-line transmittance of light having a wavelength of 550 nm measured by a spectrophotometer, and the transmittance of the fine uneven surface 10a is that only the pushers 10 are formed on the surface of the transparent base sheet 8. It measured about the sample.

  About the unevenness of the surface of the minute uneven surface 10a, it is preferable that the value of arithmetic mean surface roughness Ra defined by JIS B0601 is 1.4 μm or more. If Ra is less than 1.4 μm, the light diffusivity is low and the illumination may not be uniform. The upper limit of the Ra value is not particularly limited, but is preferably small to such an extent that the reflective surface of the individual asperities can not be visually recognized. From this point, the value of Ra is preferably 50 μm or less.

  As a method of forming the fine uneven surface 10a, in addition to a method of forming the presser 10 with a mold having an uneven surface formed by blasting or the like, an uneven layer is formed on the surface of the press 10 formed in advance by coating or printing. There is a way to In the case of forming a concavo-convex layer on the surface of the presser 10, an ink containing a filler having a particle size of about 1 to 100 μm is applied to form a fine concavo-convex surface 10a having predetermined concavities and convexities. Can.

  In addition to the same material as that of the key top 3, thermoplastic elastomer, reaction curable rubber, and reaction curable resin can be used as the material of the presser 10. As the liquid curable resin, an active energy ray curable resin or a thermosetting resin can be used. Among them, the active energy ray curing type is preferable from the viewpoint of productivity and cost. As the active energy ray, visible light, ultraviolet light, X-ray, electron beam and the like can be mentioned, but it is preferable to use ultraviolet light which is an inexpensive apparatus and whose curing process is easy, and UV curable resin is preferable for liquid curable resin. It is. Examples of the ultraviolet curable resin include acrylate resins such as polyester (meth) acrylate, urethane (meth) acrylate, silicone (meth) acrylate and epoxy (meth) acrylate.

  For example, when pressing the metal dome P1 of 5 mm in diameter, the shape of the presser 10 may be approximately cylindrical with a diameter of about 1 to 2 mm and a height of 0.1 mm or more. . Further, the top surface 10b of the presser 10 in contact with the metal dome P1 may be flat or hemispherical.

  From the viewpoint of reducing the uneven illumination, the shape of the presser 10 may be as follows. The height of the presser 10 is preferably 0.3 mm or less. This is because the area of the side surface 10 c of the presser 10 becomes smaller, and ring-shaped light corresponding to the shape of the side surface 10 c causing the uneven illumination becomes less noticeable. Moreover, the external shape which usually makes it a substantially cylindrical shape can also be made into a cross-sectional trapezoidal protrusion. The trapezoidal shape can be defined by the angle of the side surface 10c indicated by θ in FIG. 4 in addition to the height. Although θ is 90 ° in a cylinder, it is preferable to set this angle in the range of 30 to 85 ° in order to reduce uneven illumination. If it exceeds 85 °, the effect of reducing the uneven illumination is small, and if it is less than 30 °, the outer shape of the pusher 10 becomes too gentle, and the click rate may be deteriorated at the time of pressing. As the angle θ is gentle, the effect of reducing the uneven illumination becomes higher. This seems to be because the traveling direction of the light incident on the side surface 10 c of the pusher 10 and the traveling direction of the light incident on the top surface 10 b of the pusher 10 and the base sheet 8 gradually approach. On the other hand, focusing on the click rate (texture of the press) as a basic function of the pushers 10, if the angle is 45 ° or more, the click rate is approximately constant. Accordingly, the angle θ is particularly preferably in the range of 45 ° to 70 °, and among them, a value close to 45 ° is more preferable.

  As a parameter for defining the outer shape of the presser 10, a corner of the base of the presser 10 and an intersection of the side surface 10c of the presser 10 and the top surface 10b can be formed into an R-surface shape (curved surface shape). More specifically, as shown in FIG. 4, R chamfering can be performed as R1 and R2, respectively. By R-chamfering processing, the boundary of the brightly visible portion in the uneven illumination is blurred, and the uneven illumination becomes even less noticeable. The size (radius) of this R surface is preferably 0.05 to 0.3 mm. When the radius of the R surface is less than 0.05 mm, the degree of blurring of the boundary is difficult to visually recognize, and the effect of making the uneven illumination less noticeable is hardly obtained. If the radius of the R surface exceeds 0.3 mm, the outer shape of the presser 10 becomes too gentle, which may reduce the click rate. In addition to the R-chamfering process, the C-chamfering process may be performed on corner portions where the top surface 10 b and the side surface 10 c intersect. The C-chamfering process causes the brightness to change stepwise in the boundary of the brightly visible portion in the uneven illumination and provides an effect of making the uneven illumination less noticeable.

  A resin layer 9 containing a light diffusive filler is provided on the upper surface 8 a of the base sheet 8. This is a layer having a function of reflecting and refracting light by the surface of the filler contained in the resin layer 9 and diffusing the light. As such a filler, white pigments such as titanium oxide, zinc oxide and calcium carbonate, glass beads, high refractive index resin beads and the like can be used, and a white ink whose light transmittance is adjusted is particularly preferable. The resin layer 9 containing the light diffusing filler preferably has a light transmittance of 0.1% or more and less than 0.5%. When the light transmittance is 0.5% or more, the light diffusivity may be insufficient. On the other hand, if it is less than 0.1%, the amount of transmitted light is too small, and the brightness of the illumination may be excessively darkened.

  In this embodiment, the light which has entered the side face 10c of the pusher 10 by diffusing the light of the LED P2 by the fine uneven surface 10a formed on the pusher 10 as described above and the resin layer 9 containing the light diffusing filler. However, the occurrence of uneven illumination that would appear bright as ring-like light on the appearance of the keypad 1 is suppressed and illumination is uniform. The differences in their diffusion functions are as follows.

  The “fine asperity surface 10a”, which is the first diffusion layer, diffuses light by refraction and reflection with fine asperities on the surface. The directions of refraction and reflection are random or controlled, and the light changes its traveling direction to obtain a light diffusing effect as a whole. For this reason, the light beam basically changes the traveling direction by one refraction or reflection on the surface of the fine uneven surface 10a, and transmits the inside of the press 10 and the base sheet 8 to make the light diffusive filler It injects into the resin layer 9 containing. Therefore, since the reflection is not repeated inside the minute concavo-convex surface 10a, the portion irradiated with light is less likely to be bright as compared with the later-described "resin layer 9 containing a light diffusing filler". Such "fine uneven surface 10a" has high transmittance and low concealability.

  On the other hand, the “resin layer 9 containing a light diffusive filler” is a layer having a function of reflecting and refracting light on the surface of the filler contained in the resin layer 9 to diffuse the light. Although the direction of this reflection and refraction is random, light is repeatedly reflected and refracted many times in the resin layer 9 and is irradiated from the resin layer 9 to the outside. Due to such irregular reflection, the portion of the resin layer 9 irradiated with light looks bright as if it were emitting light. The “resin layer 9 containing a light diffusive filler” becomes a layer having a low transmittance and a high hiding power as compared with the fine uneven surface 10 a.

  By arranging the light diffusion layer having such different properties from the side of the LED P2 of the internal light source in the order of "finely uneven surface 10a" and "resin layer 9 containing light diffusive filler", the finely uneven surface is obtained first. The light incident on 10a is diffused and emitted, and the light is irregularly reflected in the resin layer 9 containing the light diffusive filler, so that a wide area appears bright on the surface of the resin layer 9, The ring-shaped light from the side surface 10c of the child 10 is blurred to reduce the uneven illumination of the illumination display portion 7c. By the way, when the arrangement of the two layers is reversed, it is known that the light diffusion effect is not sufficient. This is probably the next principle. That is, the light which LEDP2 of an internal light source irradiated first injects into "the resin layer 9 containing a light diffusable filler." Then, the resin layer 9 looks white in a portion where the light is irradiated. Although it can not be said that light is effectively diffused in the sense that it looks white from all directions, even if the fine concavo-convex surface 10a is disposed thereon, the fine concavo-convex surface 10a has a high transmittance, so the resin layer The brightly lit part of 9 is seen through. Therefore, a sufficient light diffusion effect can not be obtained.

  As described above, according to the keypad 1 of the present embodiment, the occurrence of uneven illumination in the illumination display portion 7c is caused by the diffusion effect of the fine uneven surface 10a of the presser 10 and the resin layer 9 containing the light diffusing filler. You can suppress the light uniformly. Therefore, the key sheet 2 and the presser sheet 3 can be disposed in proximity to the LED P2 of the internal light source. As a result, the keypad 1 can be thinned as a whole, and further, it can contribute to the thinning of the electronic device provided with the keypad 1.

  Moreover, in the keypad 1, the method of concealing uneven illumination is not employ | adopted by increasing the layer thickness of the decoration layer 7 like before. Therefore, although the keypad 1 of the present embodiment employs area illumination as the illumination method, the thickness of the decorative layer 7 is reduced to be thin and there is no conventional problem that the contrast is lowered. That is, excellent visibility can be realized by high contrast between the illuminated background portion 7b and the non-illuminated display element 7a in the illumination display portion 7c. Therefore, with the keypad 1, it is possible to realize well-lighted and well-illuminated areal illumination which can illuminate the entire illumination display section 7 c brightly and uniformly without illumination unevenness even though it is thin.

  Although the embodiment including the resin layer 9 including the light diffusive filler is exemplified in the embodiment, the resin layer 9 may not be provided. However, in this case, since only the diffusion action by the fine concavo-convex surface 10a is obtained, although the certain effect is exhibited in reducing the illumination unevenness, the effect is limited, and the combination by the resin layer 9 and the fine concavo-convex surface 10a is more effective. Irregular lighting can be reliably suppressed.

  In the embodiment described above, the resin layer 9 including the light diffusing filler is formed on the upper surface 8 a of the base sheet 8 of the presser sheet 3. However, the resin layer 9 is formed on the lower surface of the decorative layer 7 of the key sheet 2 It is also good.

  In the embodiment described above, the key sheet 2 and the presser sheet 3 are fixed by the double-sided tape 4 provided at the end of the keypad 1, and the gap between the key sheet 2 and the presser sheet 3 is an air layer. An example in which 11 is formed is shown. Even by providing the air gap 11, light is diffused on the surface of the resin layer 9 of the presser sheet 3 and the surface of the base sheet 8 and the surface of the decorative layer 7 of the key sheet 2 to reduce uneven illumination. be able to. Instead of such a configuration, the facing surfaces of the key sheet 2 and the presser sheet 3 may be fixed by the translucent adhesive layer of the double-sided tape 4 without providing the gap 11. This also diffuses the light to reduce the uneven illumination, and the key sheet 2 and the presser sheet 3 are integrated, so that the handling property at the time of assembling to the electronic device is good.

2nd Embodiment [FIGS. 5-8]: Embodiment of a decorating molded object

  In the second embodiment, an embodiment as a decorative formed body 12 will be described as an example of the decorative illumination member. For example, as shown in FIG. 5, the decorative molding 12 is incorporated into a housing A of an electronic device and used. The back surface of the decorative formed body 12 may have ribs, bosses, gate marks, and other uneven portions provided for molding reasons, which may cause uneven illumination similarly to the presser 10. is there. Therefore, by applying the present invention, it is possible to reduce the uneven illumination due to the uneven portion. An embodiment of such a decorative molded body 12 will be described based on FIGS. 5 to 8.

  The decorative molded body 12 includes an outer molded body 13 as an "exterior member" and an inner molded body 14 as an "interior member". The outer molded body 13 may be made of the same material as that of the key top 6 of the first embodiment. Among them, polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, acrylonitrile-styrene (AS) resin, acrylonitrile-butadiene-styrene (ABS) resin, and alloy resins of these are preferable.

  A decorative layer 7 is provided on the upper surface 13 a or the lower surface 13 b of the outer molded body 13. In this embodiment, the example which provides the decoration layer 7 in the upper surface 13a is shown. The decorative layer 7 can be the same as the decorative layer 7 of the first embodiment. That is, the illumination display unit 7c is provided with the display element 7a and the background portion 7b, and the illumination method is "surface illumination" in which the illumination display unit 7c is fully illuminated. A protective layer 15 such as a resin film or a hard coat layer is provided on the surface of the decorative layer 7 for protection.

  The inner molded body 14 is fixed to the lower surface 13 b of the outer molded body 13 by the adhesive layer 16 as a “light transmitting adhesive layer”. The inner formed body 14 corresponds to the presser sheet 3 in the key sheet 1, but unlike the presser sheet 3, the base sheet 8 and the presser 10 are not provided. However, when viewed optically, the concavo-convex portion 14 c formed on the lower surface 14 b of the inner molded body 14 corresponds to the pusher 10, and the concavo-convex portion 14 c is a factor that causes uneven illumination. Although the outer shape of the uneven portion 14 c is different from that of the presser 10, it is preferable that the angle of the side surface and the specification of the chamfer be the same as that of the presser 10. The material of the inner molded body 14 can be the same as that of the outer molded body 13.

  One or more uneven portions 14c are formed on at least a part of the lower surface 14b of the inner molded body 14, and in the case of having a plurality of uneven portions 14c, the entire area where the uneven portions 14c are provided is uneven surface portion 17 Define as On the surface of the uneven surface portion 17, a fine uneven surface 17a having the same configuration, operation and effects as the fine uneven surface 10a of the first embodiment is formed.

  A resin layer 9 containing a light diffusive filler is provided on the upper surface 14 a of the inner molded body 14. The resin layer 9 containing the light diffusive filler exhibits the same configuration, action and effects as the resin layer 9 containing the light diffusive filler of the first embodiment.

  According to the decorative molded body 12 of the present embodiment as described above, the uneven illumination caused by the ribs, bosses, gate marks, and the uneven portions 14c provided for other molding reasons is reduced, and the illumination display portion 7c is formed. Can achieve uniform illumination. Therefore, the decorative molded body 12 can be disposed in close proximity to the LED P 2 of the internal light source, and the decorative molded body 12 can be thinned as a whole, which can further contribute to the thinning of the electronic device.

  Further, according to the decorative molded body 12, as with the keypad 1, high contrast of the illuminated background portion 7 b and the non-illuminated display element 7 a in the illuminated display portion 7 c is adopted while adopting the illumination as an illumination method. Can achieve excellent visibility.

  Although the example which provides the decoration layer 7 in the upper surface 13a of the outer side molded object 13 was shown in the said embodiment, you may provide the decoration layer 7 in the lower surface 13b. At that time, the decorative layer 7 and the resin layer 9 containing the light diffusing filler are not directly laminated. Diffusion by the resin layer 9 is achieved by laminating the resin layer 9 including the light diffusive filler via the “gap” such as the air gap 11 of the first embodiment or the transparent adhesive layer 16 of the present embodiment. It is because the effect is enhanced. From such a viewpoint, it can be said that the configuration of the present embodiment in which the decorative layer 7 is provided on the upper surface 13 a of the outer molded body 13 is preferable. This is because the thickness of the outer molded body 13 corresponds to the “gap layer”.

Experimental Example 1:
The sample based on the keypad according to the first embodiment of the present invention and the sample for comparison were prepared, and the visibility of the uneven illumination by the pusher was evaluated.

Sample 1 [FIG. 9 (a)]
Key sheet (2): A decorative layer (7) was formed by screen printing on the lower surface (5b) of a 50 μm-thick PET film (5) using pearlescent ink containing mica as a filler. Next, a key top (6) was formed on the upper surface (5a) of the PET film (5) using a transparent UV curable resin.

Pusher sheet (3): A light is screen-printed using a white ink containing a white pigment (titanium oxide) as a light diffusing filler on the top surface (8a) of a 50 μm thick urethane film (8) A white layer (9) was formed as a resin layer containing a diffusive filler. Next, a presser (10) was formed on the lower surface (8b) of the urethane film (8) using a transparent UV-curable resin. The surface of the presser (10) is a fine uneven surface (10a) having an arithmetic average surface roughness Ra = 1.96 μm.

  With respect to the key sheet (2) and the presser sheet (3), the outer part of the key top (6) was fixed with a double-sided tape (4) to obtain a keypad (1) of sample 1. In the above sample, the transmittance when only the white layer (9) was measured was 0.24%. Moreover, the transmittance | permeability of the presser sheet | seat (3) which has not printed the white layer (9) was 3.4%.

Sample 2 [FIG. 9 (b)]
The key sheet (2) and the presser sheet (3) of sample 1 were produced by the same method as sample 1 except that the entire surface was fixed with double-sided tape.

Sample 3 [FIG. 9 (c)]
It produced by the same method as sample 1 except not having provided a white layer (9) and making it a smooth glossy surface, without providing a fine concavo-convex surface (10a) on the surface of presser sheet (3).

Sample 4 [FIG. 9 (d)]
It produced by the same method as sample 1 except having not provided a white layer (9).

Sample 5 [FIG. 9 (e)]
It produced by the same method as sample 1 except having set it as a smooth shiny side, without providing a fine concavo-convex field (10a) in the surface of press child sheet (3).

Sample 6 [FIG. 9 (f)]
Key sheet (2): A decorative layer (7) was formed by screen printing on a lower surface (5b) of a 50 μm-thick PET film (5) using a pearlescent ink. Next, using a white ink containing a white pigment (titanium oxide) as a light diffusing filler on the lower surface of the decorative layer (7), a white layer as a resin layer containing the light diffusing filler by screen printing ( 9) was formed. Furthermore, on the upper surface (5a) of the PET film (5), a key top (6) was molded using a transparent UV curable resin.

Presser sheet (3): A presser (10) was formed on the lower surface (8b) of a 50 μm thick urethane film (8) using a transparent UV-curable resin. The surface of the presser (10) was a glossy surface.

  With respect to the key sheet (2) and the presser sheet (3), the outer part of the key top (6) was fixed with a double-sided tape (4) to obtain a keypad (1) of sample 6.

Sample 7 (FIG. 9 (g))
It produced by the same method as sample 6 except having provided the same fine concavo-convex surface (10a) as sample 1 on the surface of presser sheet (3).

  In addition, about each sample, the transmittance | permeability was measured using the ultraviolet visible spectrophotometer ("UV-1600" by Shimadzu Corp. make). The transmittance was measured at a wavelength of 550 nm. Moreover, arithmetic mean surface roughness Ra was measured using the laser microscope ("UK-8510" made from Keyence Corporation).

Evaluation of uneven illumination:
For each sample, the degree of uneven illumination was evaluated by the following method. That is, as shown in FIG. 10, each sample 1 to 7 was disposed on the light source P2 (top view LED), and the appearance of the presser was visually evaluated. The evaluation results are shown in the following five steps.

5 The side of the pusher looked slightly bright.
4 The side of the pusher looked a bit bright.
3 The side of the pusher looked bright with blur.
2 The side of the pusher lighted brightly with a slight blur.
1 The side of the pusher was brightly lit clearly.

  In the sample 3 corresponding to the prior art, it was clearly seen that the light was reflected on the side of the presser and the uneven illumination was noticeable. On the other hand, the sample 4 in which the fine uneven surface was formed on the surface of the presser appeared to be somewhat blurred as the reflection of light at the side of the presser was diffused. On the other hand, also in the sample 5 in which the white layer was provided on the upper surface of the presser sheet, the reflection of the light on the side surface of the presser appeared to be diffused by the white layer, and it appeared somewhat blurred.

  In contrast to the above, Sample 6 in which the white layer was provided directly on the lower surface of the decorative layer was noticeable compared to Sample 5 although the reflection of light was less visible than Sample 3.

  In the case of the sample 7 having the features of the sample 4 and the sample 6 as compared with the sample 4 and the sample 6, the reflection of light on the side surface of the pusher appeared to be more diffused and appeared to be blurred.

  In the case of the sample 1 having both the features of the sample 4 and the sample 6, compared with the sample 7, the reflection of the light on the side face of the presser is diffused, and it is difficult to see the bright part. Moreover, similarly, in the sample 2 in which the entire surfaces of the key sheet and the presser sheet were fixed with the double-sided tape, it was difficult to see the bright part in the same manner.

  Summarizing the above, the degree of illumination unevenness is the result of Sample 3 <Sample 6 <Sample 4 <Sample 5 <Sample 7 <Sample 1 <Sample 1 試 料 Sample 2.

  From the comparison between the sample 3 and the sample 4, it was found that the unevenness in illumination can be reduced by providing the micro uneven layer on the surface of the presser. This seems to be because the light reflected by the side surface of the presser is refracted and reflected at random in the direction of travel of light by the fine concavo-convex layer, so that the light does not concentrate on a specific part of the decorative layer Be

  The comparison of the sample 3 with the sample 5 with the sample 6 shows that the first example of providing the white layer can reduce the uneven illumination. Second, it was found that uneven illumination can be greatly reduced if the white layer is provided on the presser sheet than on the surface of the decorative layer. It is considered that the first effect is that the light reflected by the side surface of the presser is irregularly reflected repeatedly in the white layer, so that it is difficult for the light to be concentrated on a specific part of the decorative layer. The second effect is considered as follows. Sample 5 differs from sample 6 in having a gap between the white layer and the decorative layer. That is, it is thought that uneven illumination can be reduced more effectively by providing a distance for the light emitted from the white layer to be diffused in a wider range.

  With regard to the comparison between the sample 7 and the sample 1, it is considered that the sample 1 can reduce the uneven illumination more effectively due to the same relationship as the relation between the sample 6 and the sample 5.

  In the comparison between the sample 1 and the sample 2, although the degree of reduction of the illumination unevenness was the same level, the sample 1 appeared a little smaller in the illumination unevenness. This seems to be because in the sample 1 having no double-sided tape, some irregular reflection occurred on the surface of the decorative layer and the surface of the white layer, and the unevenness in illumination was slightly reduced.

Experimental Example 2:
A sample having the same configuration as that of the sample 1 of the experimental example 1 but different in only the arithmetic mean surface roughness Ra of the surface of the presser was produced, and the visibility of uneven illumination due to the presser was evaluated. In addition, the value of said arithmetic mean surface roughness Ra was adjusted by changing the roughness of the blasting process of a metal mold | die. The height of the presser in this sample is 0.26 mm, the diameter of the presser is 1.5 mm, and the inclination angle of the side of the presser is 85 °.

  From the evaluation results of the illumination unevenness of the sample 1 and the samples 8 to 11, it was found that the illumination unevenness is reduced in the sample having the arithmetic average surface roughness value of Ra = 1.40 μm or more. Moreover, it turned out that illumination nonuniformity becomes difficult to see especially if Ra = 1.55 or more.

  The configurations shown in each of the above-described embodiments, modifications, and examples can be combined without departing from the spirit of the present invention.

1 Keypad (1st embodiment of a decorative illumination member)
2 Key sheet (exterior member)
3 Pusher sheet (interior member)
4 double-sided adhesive tape 5 base sheet 5a upper surface 5b lower surface 6 key top 7 decorative layer 7a display element 7b background portion 7c illuminated light display portion 8 base sheet 8a upper surface 8b lower surface 9 resin layer 10 containing a light diffusing filler )
DESCRIPTION OF SYMBOLS 10a Finely uneven surface 10b Top surface 10c Side surface 11 Gap 12 A decorative molded body (a second embodiment of a decorative illumination member)
13 Outer molded body (exterior member)
13a upper surface 13b lower surface 14 inner formed body (interior member)
14a upper surface 14b lower surface 14c uneven portion 15 protective layer 16 adhesive layer 17 uneven surface portion 17a fine uneven surface P printed circuit board P1 contact switch, metal dome P2 LED (internal light source)

Claims (8)

In a decorative illumination member having an illumination display unit illuminated by the light of an internal light source,
A translucent exterior member provided with a decorative layer having the illumination display portion;
The upper surface is disposed on the side of the exterior member, the lower surface is disposed on the side of the internal light source, and the translucent interior member having the uneven surface portion at a position below the illumination display portion on the lower surface is provided.
The surface of the uneven surface portion has a fine uneven surface having a transmittance of 0.5 to 20%,
What is claimed is: 1. A decorative illumination member, comprising: a gap formed of an air layer at an entire position where the internal light source and the illumination display unit overlap between the exterior member and the interior member. In a decorative illumination member having an illumination display unit illuminated by the light of an internal light source,
A translucent exterior member provided with a decorative layer having the illumination display portion;
The upper surface is disposed on the side of the exterior member, the lower surface is disposed on the side of the internal light source, and the translucent interior member having the uneven surface portion at a position below the illumination display portion on the lower surface is provided.
The surface of the uneven surface portion has a fine uneven surface having a transmittance of 0.5 to 20%,
A translucent illumination member characterized by having a translucent adhesion layer which pastes the exterior member and the interior member in the whole position to which the internal light source and the illumination display part overlap. The decorative illumination member according to claim 1 or 2, further comprising a resin layer containing a light diffusing filler at a position below the illumination display portion. The decorative illumination member according to claim 3, wherein the transmittance of the fine uneven surface is higher than the transmittance of the resin layer. The decorative illumination member according to claim 3, wherein the resin layer is provided on the surface of the interior member facing the exterior member. The decorative illumination member according to any one of claims 3 to 5, wherein the resin layer is provided on the surface of the exterior member facing the interior member. The exterior member is an input operation sheet made of a resin film having the decorative layer in which a display element of characters, numbers, symbols or figures and a background portion thereof are formed as the light emitting display portion,
The decorative illumination member according to any one of claims 1 to 6, wherein the interior member is a presser sheet made of a resin film having a presser as the uneven surface portion. The exterior member is an outer molded body made of a resin molded body having the display layer of a character, a numeral, a symbol or a figure as the illumination display portion and the background portion thereof,
The decorative illumination member according to any one of claims 1 to 6, wherein the interior member is an inner molded body made of a resin molded body having an uneven portion as the uneven surface portion.

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