JP2016085926A - Decorative illumination member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress uneven illumination derived from the internal shape of a decorative illumination member, such as a keypad having an illumination display part, and occurring in the illumination display part.SOLUTION: A keypad 1 has a key sheet 2 and a pusher sheet 3, and a pusher 10 causing illumination unevenness, illuminating like a ring, in the illumination display part 7c of the key sheet 2 is formed on the lower surface of the pusher sheet 3. A fine uneven surface 10a is formed on the surface of the pusher 10. Furthermore, a resin layer 9 containing a light diffusion filler is formed on the upper surface of the pusher sheet 3. Illumination unevenness can be blurred by the light diffusion effect by these fine uneven surface 10a and resin layer 9.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a decorative illuminating member having an illuminating display that illuminates with light from an internal light source. This decorative illumination member can be used as an input operation member (keypad, 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 electronic device is required to be further reduced in size and thickness together with the electronic device. Therefore, for example, in an electronic device that uses an LED as an internal light source and is illuminated with the light, the internal light source and the input operation member tend to be arranged closer to each other. This is one cause of causing “illumination unevenness”, which is undesirable as illumination quality, to the input operation member as a decorative illumination member. This will be specifically described with a keypad as a decorative illumination member.

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

  Therefore, this keypad is configured to be thin with a base sheet provided with a key top and a presser sheet. A decorative layer is printed on the base sheet of the keypad. The decoration layer is formed with an “illuminated display portion” having a display element representing characters, numbers, symbols or figures and a background portion thereof, and is illuminated by the light of the LED mounted on the substrate directly below or in the vicinity thereof. It is like that. Such a keypad has the advantage of being simple and inexpensive.

JP 2012-164450 A

  However, the above-described keypad has a problem that when illuminated, the light that enters the side surface of the transparent hard resin truncated cone-shaped pusher appears as a ring-shaped light and looks bright on the appearance of the keypad. . The ring-shaped light causes “illumination unevenness” that hinders the desired uniform illumination in the illumination display portion, and therefore needs to be made as inconspicuous as possible.

  As a means for concealing the ring-shaped light, for example, it is conceivable to increase the layer thickness of the decorative layer that is a printed layer. If the decorative layer is printed in multiple layers, it is possible to conceal the ring-shaped light. However, the more layers are printed, the more difficult it is for the light from the internal light source to pass through, and the illumination of the decorative layer becomes dim as a whole. If it does so, the contrast of an illumination display part will become difficult to take out, and there exists a problem that visibility will be worsened. This problem also restricts the selection of the illumination display method as follows.

  That is, there are two types of illumination display of the illumination display unit: “surface illumination” and “character illumination”. “Surface illumination” is a method in which a display element of characters, numbers, symbols or figures and a background part thereof are formed by an opaque printing layer, and a background part around the display element is illuminated. “Character illumination” is a method in which these display elements are formed as an opaque printed layer having a blank shape, and display elements without the printed layer are illuminated. Among these, “surface illumination” is a preferable illumination method that can brightly illuminate the entire illumination display unit to improve visibility, and the display element is easily visible from the contrast with the background portion that is illuminated. There is. However, this "surface illumination" has a problem that the ring-shaped light described above can be seen on the display element and the surrounding background portion, and as a concealing method, it is effective in addition to multilayer printing layers in which the illumination display portion becomes dim. Since there was no improvement measure, after all, "character illumination" that can easily conceal ring-shaped light has been used. Because “character illumination” illuminates the display element and shields the surrounding area, the illumination area is small, making the ring-shaped light inconspicuous, and adjusting the position of the character so that it is on the ring-shaped light. This is because an opaque background could be placed. In this way, the ring-shaped light generated by the pusher is a great restriction for the selection of the illumination method of the keypad.

  In the above, the problem of ring-shaped light caused by the pusher of the keypad has been described. However, it has been found that even an uneven part like the pusher can cause “irradiation unevenness” in the illumination display part. Yes.

  The present invention has been made against the background of the prior art as described above. The purpose is to suppress uneven illumination that occurs in the illuminated display part due to the internal shape of the decorative illuminated member such as a keypad having the illuminated display part.

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

  The present invention relates to a decorative illuminating member having an illuminating display portion that is illuminated by light from an internal light source, and a translucent exterior member provided with a decorative layer having the illuminating display portion, and an upper surface disposed on the exterior member side. A light-transmitting interior member having a concavo-convex surface portion at a position below the illumination display portion on the lower surface, the surface of the concavo-convex surface portion being a fine concavo-convex surface Features.

  The uneven surface portion of the interior member corresponds to the above-described pusher that generates ring-shaped light, and the light that enters the side surface of the uneven surface portion can cause the light of the side surface shape to appear bright on the exterior of the exterior member. is there. However, in the present invention, the surface of the concavo-convex surface portion including the side surface has a fine concavo-convex surface, which blurs the side-shaped light that appears bright in the appearance of the exterior member. Therefore, according to the decorative illuminating member of the present invention, it is possible to uniformly illuminate while suppressing the occurrence of uneven illumination in the illuminated display section. Thereby, the decorative illuminating member can be thinned as a whole, and the uneven surface portion of the interior member can be disposed close to the internal light source, which can contribute to the thinning of the electronic device including the decorative illuminating member. . In addition, even when surface illumination is used as the illumination method, the conventional problem that the contrast is lowered due to the dimming of the printed layer does not occur, and the illumination portion and the non-illumination portion (display element) are not affected. It is possible to improve visibility by high contrast.

  A lower layer of the illumination display unit has a resin layer containing a light diffusing filler.

  According to the resin layer containing the light diffusing filler, the light of the side surface shape of the concavo-convex surface portion diffused by the fine concavo-convex surface is further blurred by being diffused widely by repeating reflection and refraction inside the resin layer. be able to. Therefore, the generation of uneven illumination in the illumination display unit can be suppressed and more uniform illumination can be realized.

  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, it is possible to maintain the brightness at the stage where light diffused by the fine uneven surface enters the uneven surface portion, and light emitted from the uneven surface portion. Is diffused widely in the resin layer having a low transmittance, so that the generation of uneven illumination can be effectively suppressed by diffusion without significantly reducing the illumination brightness in the illumination display portion.

  About the said resin layer, it can provide in the surface facing the exterior member in an interior member, or can be provided in the surface facing the interior member in an exterior member.

  The resin layer exhibits a light diffusing effect regardless of whether the resin layer is provided, but it is possible to 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 a gap between the exterior member and the illumination display unit, the distance between the exterior member and the illumination member is increased, and these effectively work for the blurring effect.

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

  According to this, unevenness of illumination can be reduced by diffusing light on the respective surfaces of the interior member and the exterior member facing each other.

  Between the exterior member and the interior member, a translucent adhesive for attaching them can be provided.

  According to this, light non-uniformity can be reduced by diffusing light also by the translucent adhesive layer, and the exterior member and the interior member are integrated, so that the handleability when assembled to an electronic device is good.

  More specifically, the decorative illuminating 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 letters, numbers, symbols or figures as the illumination display portion and a decorative layer forming the background portion thereof, and the interior member is In addition, it can be configured as a pusher sheet made of a resin film having a pusher as the uneven surface portion. That is, it can be configured as a keypad.

  In addition, the decorative illuminating member of the present invention is more specifically a resin molding in which the exterior member has a decorative layer in which a display element of letters, numbers, symbols or figures and a background part thereof are formed as the illuminating display part. It is an outer side molded object which consists of a body, and an interior member can be constituted as an inner side molded object which consists of a resin molding which has an uneven part as the uneven surface part. That is, it can be configured as a decorative molded body.

  According to the decorative illuminating member of the present invention, it is possible to uniformly illuminate while suppressing the occurrence of uneven illumination in the illuminated display section. For this reason, the uneven | corrugated surface part of an interior member can be arrange | positioned adjacent to an internal light source, a decorative illumination member can be reduced in thickness as a whole, and it can contribute also to thickness reduction of an electronic device provided with a decorative illumination member.

  According to the decorative illuminating member of the present invention, even if the surface illuminating is adopted as the illuminating method, the conventional problem that the contrast becomes lower due to the dimming as in the multilayered printing layer does not occur. In other words, it is possible to improve visibility by high contrast between the illuminated background portion and the non-illuminated display element in the illuminated display portion. Therefore, with the decorative illuminating member of the present invention, it is possible to realize surface illumination with good visibility that can illuminate the entire illumination display unit as an illumination system, although it is thin.

The front view of the keypad of 1st Embodiment. FIG. 3 is a sectional view taken along line SA-SA in FIG. 1. The SB part expanded sectional view of FIG. FIG. 4 is an enlarged cross-sectional view around the pusher in FIG. 3. The perspective view of the decorative molded body of 2nd Embodiment. The front view of the decorative molded body of FIG. SC-SC sectional view taken on the line of FIG. The SD section enlarged view of FIG. It is sectional drawing equivalent to FIG. 3 which shows the structure of the keypad of Experimental example 1, (a)-(g) is sectional drawing of samples 1-7, respectively. Explanatory drawing which shows the test method of Experimental example 1. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, duplication description is abbreviate | omitted about the material, a structure, a function, a manufacturing method, etc. which are common in each embodiment.

First Embodiment [FIGS. 1 to 4]: Embodiment of Keypad

  1st Embodiment demonstrates embodiment as the keypad 1 as an example of a decorating illumination member. In the following description of the keypad 1, “upper surface”, “lower surface”, “front surface”, and “rear surface” represent the surface on the side of the printed circuit board P of the member to be described as “lower surface” or “back surface”, respectively. The surface side is expressed as “upper surface”. In addition, when “surface” is described, a predetermined outer surface including an upper surface and a lower surface is indicated. 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 pusher 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 arranged on the upper surface 5a, and a decorative layer 7 is formed on the lower surface 5b. The presser sheet 3 also includes a base sheet 8, a resin layer 9 including a light diffusing filler is formed on the upper surface 8 a, and a presser 10 corresponding to each key top 6 is formed on the lower surface 8 b. Is formed. The pusher 10 corresponds to the “uneven surface portion” of the present invention. The surface of the pusher 10 is formed as a fine uneven surface 10a.

  The following materials can be used for the base sheet 5 of the key sheet 2 and the base sheet 8 of the pusher sheet 3.

  The base sheet 5 is a base material of the key sheet 2 and is formed in a rectangular shape in plan view. The base sheet 8 is a base material of the pusher sheet 3 and is formed in a rectangular shape in plan view like the base sheet 5. These base sheets 5 and 8 are flexibly deformed when the keypad 1 is pressed, and are flexible enough to press the contact switch P1 such as a metal dome of the printed board P provided on the back side of the keypad 1. Have. Such base sheets 5 and 8 are formed as a flat piece. The thickness is preferably 50 μm to 300 μm, respectively, because of the demand for thin keypad 1. 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 united (ABS) film, a polypropylene (PP) film, a polyethylene (PE) film, a triacetyl cellulose (TAC) film, or a film obtained by alloying or blending them can be used. Moreover, a woven fabric, a nonwoven fabric, etc. are mentioned other than the film made from a synthetic resin.

  On the upper surface 5a or the lower surface 5b of the base sheet 5, a display layer 7a representing characters, numbers, symbols or figures and a decoration layer 7 representing the background portion 7b are formed. In this 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. In this embodiment, the decorative layer 7 is provided as a printing layer by screen printing. Specifically, the decoration layer 7 is composed of, for example, a black print layer that becomes the display element 7a, and a white print layer that becomes the background portion 7b. In the present embodiment, an illumination method using “surface illumination” is adopted by the decorative layer 7. That is, the “surface illumination” is a preferable illumination method that can brightly illuminate the entire illumination display portion 7c to improve visibility, and the display element 7a (black) that is not illuminated by contrast with the background portion 7b (white) to be illuminated. Is easy to see.

  The illumination display unit 7c can be variously set according to the design of the keypad 1 and the illumination method. In this embodiment, since the entire surface of the keypad 1 is designed to be illuminated, the illuminated display portion 7c is the entire surface of the keypad 1. In addition, for example, the decoration layer 7 may be formed by setting only the portion of the lower surface 5b of the base sheet 5 corresponding to the key top 6 as an illumination display portion. In this case, you may make it provide a light shielding layer as a part of the decoration layer 7 in the part which is not set as an illumination display part.

  The key top 6 is a member that becomes 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 improve the visibility of the decorative layer 7, and a thermoplastic resin or a reactive curable resin is used. Examples thereof include polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, acrylonitrile / styrene (AS) resin, acrylonitrile / butadiene / styrene (ABS) resin, and alloy resins thereof. Examples of thermosetting resins include a reaction curable resin composition that is liquid at room temperature (hereinafter referred to as “liquid curable resin”) containing a polymer, oligomer, monomer, polymerization initiator, additive, and the like. Can be used. As the reaction form of the liquid curable resin, an active energy ray curable type or a thermosetting type can be used. Of these, the active energy ray curable type is preferable from the viewpoint of productivity and cost. Examples of active energy rays include visible light, ultraviolet rays, X-rays, electron beams, etc., but it is preferable to use ultraviolet rays that are inexpensive and have a simple curing process, and ultraviolet curable resins are suitable for liquid curable resins. 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. Note that the key top 6 is not necessarily fixed to the pressing operation portion, and a single sheet-like key sheet having a flat surface with no unevenness may be used. The key tops may be separated one by one.

  A pusher 10 is provided on the lower surface 8 b of the base sheet 8 of the pusher sheet 3. A fine uneven surface 10 a is formed on the entire surface of the pusher 10. The fine concavo-convex surface 10a is also a light diffusion layer having a function of refracting and irregularly reflecting light irradiated by the LEDP2 provided on the printed board P as an internal light source.

  The transmittance of the fine uneven surface 10a is preferably 0.5% or more. When the transmittance is less than 0.5%, the luminance of illumination may be too low. More preferably, the transmittance is 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 diffusibility becomes insufficient, and there is a possibility that the light cannot be illuminated uniformly. The pusher 10 including the fine uneven surface 10a is particularly preferably colorless, but may be other than colorless. The transmittance in the present invention is a parallel line transmittance of light having a wavelength of 550 nm measured with a spectrophotometer, and the transmittance of the fine uneven surface 10 a is formed only on the surface of the transparent base sheet 8 with the presser 10. It is measured for a sample.

  About the unevenness | corrugation of the surface of the fine unevenness | corrugation surface 10a, it is preferable that the value of arithmetic mean surface roughness Ra defined by JISB0601 is 1.4 micrometers or more. This is because when Ra is less than 1.4 μm, light diffusibility is low and illumination may not be uniform. The upper limit of the Ra value is not particularly limited, but is preferably small so that the reflective surface of each unevenness cannot 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 previously formed presser 10 by coating or printing. There is a way to do it. When forming an uneven layer on the surface of the presser 10, the fine uneven surface 10a having a predetermined unevenness is formed by applying a transparent ink including a filler having a particle diameter of about 1 to 100 μm. Can do.

  As for the material of the pusher 10, in addition to the same material as the key top 3, a thermoplastic elastomer, a reaction curable rubber, and a reaction curable resin can be used. As the liquid curable resin, an active energy ray curable resin or a thermosetting resin can be used. Of these, the active energy ray curable type is preferable from the viewpoint of productivity and cost. Examples of active energy rays include visible light, ultraviolet rays, X-rays, electron beams, etc., but it is preferable to use ultraviolet rays that are inexpensive and have a simple curing process, and ultraviolet curable resins are suitable for liquid curable resins. 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 shape of the pusher 10 can be arbitrary. For example, when pressing a metal dome P1 having a diameter of 5 mm, the pusher 10 has a substantially cylindrical shape having a diameter of about 1 to 2 mm and a height of 0.1 mm or more. . Further, the top surface 10b of the pusher 10 that contacts the metal dome P1 may be flat or hemispherical.

  From the viewpoint of reducing uneven illumination, the shape of the pusher 10 is preferably as follows. The height of the pusher 10 is preferably 0.3 mm or less. This is because the area of the side surface 10c of the pusher 10 becomes smaller, and the ring-shaped light corresponding to the shape of the side surface 10c that causes uneven illumination is less noticeable. In addition, the outer shape that is generally substantially columnar can be a protrusion having a trapezoidal cross section. 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. In a cylinder, θ is 90 °, but it is preferable to set this angle in a range of 30 to 85 ° in order to reduce uneven illumination. If it exceeds 85 °, the effect of reducing illumination unevenness is small, and if it is less than 30 °, the outer shape of the pusher 10 becomes too smooth, and the click rate may be deteriorated during pressing. The gentler the angle θ, the higher the effect of reducing uneven illumination. This seems to be because the traveling direction of the light incident on the side surface 10c of the pusher 10 gradually approaches the traveling direction of the light incident on the top surface 10b of the pusher 10 and the base sheet 8. On the other hand, when attention is paid to the click rate (the texture of pressing) as a basic function of the pusher 10, if the angle is 45 ° or more, the click rate is substantially constant. Therefore, the angle θ is particularly preferably in the range of 45 ° to 70 °, and more preferably a value close to 45 °.

  As a parameter for defining the outer shape of the pusher 10, the root of the pusher 10 and the corner where the side surface 10c of the pusher 10 intersects the top surface 10b can be 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 performing the R chamfering process, the boundary of the brightly visible portion of the uneven illumination is blurred, and the uneven illumination is further less noticeable. The size (radius) of the R surface is preferably 0.05 to 0.3 mm. This is because when the radius of the R surface is less than 0.05 mm, the blurring of the boundary is difficult to see with the naked eye, and the effect of making the illumination unevenness inconspicuous is hardly obtained. This is because when the radius of the R surface exceeds 0.3 mm, the outer shape of the pusher 10 becomes too gentle, and the click rate may be reduced. In addition, you may give C chamfering about the corner | angular part which the top surface 10b and the side surface 10c cross instead of R chamfering. This is because the brightness of the boundary of the brightly appearing portion in the uneven illumination is changed stepwise by the C chamfering process, and the effect of making the uneven illumination inconspicuous is obtained.

  On the upper surface 8a of the base sheet 8, a resin layer 9 containing a light diffusing filler is provided. This is a layer having a function of diffusing light by reflecting and refracting light on the surface of the filler contained in the resin layer 9. 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 white ink with adjusted light transmittance is particularly suitable. The resin layer 9 containing the light diffusing filler preferably has a light transmittance of 0.1% or more and less than 0.5%. If the light transmittance is 0.5% or more, the light diffusibility may be insufficient. On the other hand, if it is less than 0.1%, the amount of transmitted light is too small, and the luminance of illumination may become excessively dark.

  In this embodiment, the light that has entered the side surface 10c of the pusher 10 by diffusing the light of the LEDP2 by the fine uneven surface 10a formed on the pusher 10 and the resin layer 9 containing the light diffusing filler as described above. However, it is possible to uniformly illuminate the keypad 1 while suppressing the occurrence of uneven illumination that appears bright as ring-shaped light on the exterior of the keypad 1. The difference between the diffusion functions will be described as follows.

  The “fine uneven surface 10a” that is the first diffusion layer diffuses light by refraction and reflection with fine unevenness on the surface. The direction of refraction and reflection is random or controlled, and the light changes its traveling direction so that a light diffusion effect can be obtained as a whole. For this reason, the light beam basically changes the traveling direction by refraction or reflection once on the surface of the fine uneven surface 10a, and passes through the inside of the pusher 10 or the base sheet 8 to form the light diffusing filler. Incident on the resin layer 9 to be included. Therefore, since the reflection is not repeated inside the fine uneven surface 10a, the portion irradiated with light is hard to be seen as compared with the “resin layer 9 containing a light diffusing filler” described later. Such a “fine uneven surface 10a” has a high transmittance and a low concealing property.

  On the other hand, the “resin layer 9 containing a light diffusing filler” is a layer having a function of diffusing light by reflecting and refracting light on the surface of the filler contained in the resin layer 9. Although the directions of reflection and refraction are random, light is repeatedly reflected and refracted in the resin layer 9 and 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. This “resin layer 9 containing a light diffusing filler” is a layer having a low transmittance and a high concealing property as compared with the fine uneven surface 10a.

  By arranging the light diffusing layers having different properties as viewed from the LEDP2 side of the internal light source in the order of the “fine uneven surface 10a” and the “resin layer 9 containing a light diffusing filler”, the fine uneven surface is first formed. The light incident on 10a is diffused and emitted, and the light is irregularly reflected in the resin layer 9 including the light diffusing filler, so that a wide range appears bright on the surface of the resin layer 9, which is pushed. The ring-shaped light from the side surface 10c of the child 10 is blurred to reduce uneven illumination of the illumination display portion 7c. By the way, it is known that the light diffusion effect is not sufficient when the arrangement of the two layers is reversed. This is probably the next principle. That is, the light irradiated by the internal light source LEDP2 first enters the “resin layer 9 containing a light diffusing filler”. As a result, the resin layer 9 appears to shine white at the portion irradiated with light. Although it can be said that light is effectively diffused in the sense that it looks white from all directions, even if the fine uneven surface 10a is disposed thereon, the fine uneven surface 10a has a high transmittance, so that the resin layer 9 brightly shining part can be seen through. For this reason, a sufficient light diffusion effect cannot be obtained.

  As described above, according to the keypad 1 of the present embodiment, uneven illumination in the illumination display portion 7c is generated by the diffusion effect by the fine uneven surface 10a of the pusher 10 and the resin layer 9 including the light diffusing filler. It can be suppressed and evenly illuminated. For this reason, the key sheet 2 and the presser sheet 3 can be disposed in proximity to the LEDP2 as the internal light source. As a result, the keypad 1 as a whole can be reduced in thickness, and the electronic device including the keypad 1 can also be reduced in thickness.

  In addition, the keypad 1 does not employ a method of concealing the illumination unevenness by increasing the layer thickness of the decoration layer 7 as in the prior art. Therefore, the keypad 1 of the present embodiment employs surface illumination as an illumination method, but the conventional problem that the contrast becomes lower due to the layer thickness of the decorative layer 7 does not occur. That is, it is possible to realize excellent visibility due to high contrast between the illuminated background portion 7b and the non-illuminated display element 7a in the illuminated display portion 7c. Therefore, if the keypad 1 is thin, it is possible to realize surface illumination with good visibility that can illuminate the entire illumination display unit 7c as an illumination method without causing uneven illumination.

  In the said embodiment, although embodiment provided with the resin layer 9 containing a light diffusable filler was illustrated, it can also be set as the structure which does not provide the resin layer 9. FIG. However, in this case, since only the diffusion action by the fine uneven surface 10a is obtained, the effect is limited although the effect of reducing illumination unevenness is limited, and the combination of the resin layer 9 and the fine uneven surface 10a is more effective. Irradiation unevenness can be reliably suppressed.

  In the said embodiment, although the example which forms the resin layer 9 containing a light diffusible filler in the upper surface 8a of the base sheet 8 of the presser sheet | seat 3 was formed in the lower surface of the decorating layer 7 of the key sheet 2, Also good.

  In the embodiment, 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 formed by an air layer is provided between the key sheet 2 and the presser sheet 3. An example in which 11 is formed is shown. The provision of the air gap 11 also diffuses light on the surface of the resin layer 9 and the base sheet 8 of the pusher sheet 3 and the surface of the decoration layer 7 of the key sheet 2 to reduce uneven illumination. be able to. Instead of such a configuration, the opposing surfaces of the key sheet 2 and the presser sheet 3 may be fixed by a light-transmitting adhesive layer using the double-sided tape 4 without providing the gap 11. This also diffuses light to reduce uneven illumination, and since the key sheet 2 and the pusher sheet 3 are integrated, the handleability when assembled to an electronic device is good.

Second embodiment [FIGS. 5 to 8]: Embodiment of a decorative molded body

  In the second embodiment, an embodiment as a decorative molded body 12 will be described as an example of a decorative illumination member. For example, as shown in FIG. 5, the decorative molding 12 is used by being incorporated in a casing A of an electronic device. The back surface of the decorative molded body 12 may have ribs, bosses, gate traces, and other irregularities provided for molding reasons, which may cause uneven illumination similar to the pusher 10. is there. Therefore, by applying the present invention, it is possible to reduce uneven illumination caused by such uneven portions. An embodiment of such a decorative molded body 12 will be described with reference to FIGS.

  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 can be made of the same material as 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 thereof are particularly preferable.

  The decoration 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 decoration layer 7 can be the same as the decoration layer 7 of the first embodiment. That is, the illumination display portion 7c is provided with a display element 7a and a background portion 7b, and the illumination method is “surface illumination” in which the illumination display portion 7c is entirely 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 an adhesive layer 16 as a “translucent adhesive layer”. The inner molded body 14 corresponds to the pusher sheet 3 in the key sheet 1, but unlike the pusher sheet 3, the base sheet 8 and the pusher 10 are not provided. However, when viewed optically, the uneven portion 14 c formed on the lower surface 14 b of the inner molded body 14 corresponds to the pusher 10, and this uneven portion 14 c causes uneven illumination. Although the concavo-convex portion 14 c has an outer shape different from that of the pusher 10, the side surface angle and chamfering specifications are preferably the same as those of the pusher 10. The material constituting 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 when the plurality of uneven portions 14c are provided, the entire region where the uneven portions 14c are provided is the uneven surface portion 17. It is defined as On the surface of the concavo-convex surface portion 17, a fine concavo-convex surface 17 a having the same configuration, action and effect as the fine concavo-convex surface 10 a of the first embodiment is formed.

  A resin layer 9 including a light diffusing filler is provided on the upper surface 14 a of the inner molded body 14. The resin layer 9 including the light diffusing filler has the same configuration, action and effect as the resin layer 9 including the light diffusing filler of the first embodiment.

  According to the decorative molded body 12 of the present embodiment as described above, the uneven illumination 14c caused by the ribs, bosses, gate marks, and other uneven portions 14c provided for molding reasons is reduced, and the illuminated display portion 7c. Can achieve uniform illumination. Therefore, the decorative molded body 12 can be disposed close to the LEDP2 as the internal light source, and the decorative molded body 12 can be thinned as a whole, and further contribute to the thinning of the electronic device.

  Further, according to the decorative molded body 12, similarly to the keypad 1, while adopting surface illumination as the illumination method, the high contrast between the background portion 7b illuminated in the illumination display portion 7c and the non-illuminated display element 7a. Excellent visibility can be achieved.

  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. The resin layer 9 containing the light diffusing filler is laminated through the “gap layer” such as the air gap 11 of the first embodiment and the transparent adhesive layer 16 of the present embodiment, so that the diffusion by the resin layer 9 is performed. This is because the effect is enhanced. From this point of view, it can be said that the configuration of the present embodiment in which the decorative layer 7 is provided on the upper surface 13a 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:
A sample based on the keypad according to the first embodiment of the present invention and a sample for comparison were produced, and the visibility of uneven illumination by the pusher was evaluated.

Sample 1 [FIG. 9 (a)]
Key sheet (2): A decorative layer (7) was formed on the lower surface (5b) of a PET film (5) having a thickness of 50 μm by screen printing using a pearly 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.

Presser sheet (3): Using a white ink containing a white pigment (titanium oxide) as a light diffusing filler on the upper surface (8a) of a 50 μm-thick urethane film (8), light is printed by screen printing. A white layer (9) was formed as a resin layer containing a diffusible 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 pusher (10) is a fine uneven surface (10a) having an arithmetic average surface roughness Ra = 1.96 μm.

  About the said key sheet | seat (2) and the presser sheet | seat (3), the outer side part of the key top (6) was fixed with the double-sided tape (4), and the keypad (1) of the sample 1 was obtained. In the sample, the transmittance measured for only the white layer (9) was 0.24%. The transmittance of the presser sheet (3) on which the white layer (9) was not printed was 3.4%.

Sample 2 [FIG. 9B]
The key sheet (2) and the pusher sheet (3) of Sample 1 were produced in the same manner as Sample 1, except that the entire surface was fixed with double-sided tape.

Sample 3 [FIG. 9 (c)]
It was produced by the same method as Sample 1 except that the white layer (9) was not provided and that the surface of the presser sheet (3) was a smooth glossy surface without providing the fine uneven surface (10a).

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

Sample 5 [FIG. 9 (e)]
It was produced by the same method as Sample 1 except that the surface of the presser sheet (3) was a smooth glossy surface without providing the fine uneven surface (10a).

Sample 6 [FIG. 9 (f)]
Key sheet (2): A decorative layer (7) was formed on the lower surface (5b) of a PET film (5) having a thickness of 50 μm by screen printing using a pearly 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) formed. Further, a key top (6) was formed on the upper surface (5a) of the PET film (5) using a transparent UV curable resin.

Presser sheet (3): A presser (10) was molded 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.

  About the said key sheet | seat (2) and the presser sheet | seat (3), the outer side part of the key top (6) was fixed with the double-sided tape (4), and the keypad (1) of the sample 6 was obtained.

Sample 7 [FIG. 9 (g)]
It was produced by the same method as Sample 6, except that the same fine uneven surface (10a) as Sample 1 was provided on the surface of the presser sheet (3).

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

Evaluation of illumination unevenness:
The degree of uneven illumination was evaluated for each sample by the following method. That is, as shown in FIG. 10, each sample 1-7 was arrange | positioned on the light source P2 (top view LED), and the appearance of a pusher was evaluated visually. The evaluation results are shown in the following five stages.

5 The side of the pusher looked slightly bright.
4 The side of the pusher seemed slightly bright.
3 The side of the pusher looked bright and blurred.
2 The side of the pusher shined brightly in a slightly blurred state.
1 The side of the pusher was shining brightly and brightly.

  In the sample 3 corresponding to the prior art, the light reflected from the side surface of the pusher was clearly bright and the illumination unevenness was conspicuous. On the other hand, the sample 4 in which the fine uneven surface was formed on the surface of the pusher appeared to be slightly blurred because the reflection of light on the side surface of the pusher was diffused. On the other hand, Sample 5 provided with a white layer on the upper surface of the presser sheet also appeared to be slightly blurred because the light reflection on the side surface of the presser was diffused by the white layer.

  On the other hand, the sample 6 in which the white layer was directly provided on the lower surface of the decorative layer was conspicuous when compared with the sample 5 although the light reflection was less visible than the sample 3.

  The sample 7 having the characteristics of the sample 4 and the sample 6 seemed to be blurred as compared with the sample 4 and the sample 6 because the reflection of light on the side surface of the pusher was more diffused.

  In the case of the sample 1 having both the characteristics of the sample 4 and the sample 6, even when compared with the sample 7, the reflection of light on the side surface of the pusher is diffused, and the brightly shining portion is considerably difficult to see. Similarly, in the sample 2 in which the entire surface of the key sheet and the presser sheet was fixed with the double-sided tape, the brightly shining portion was also considerably difficult to see.

  In summary, the degree of uneven illumination is the result of sample 3 <sample 6 <sample 4 <sample 5 <sample 7 <sample 1≈sample 2.

  From comparison between Sample 3 and Sample 4, it was found that uneven illumination can be reduced by providing a fine uneven layer on the surface of the presser. This is thought to be because the light reflected from the side of the pusher is refracted and reflected randomly by the fine concavo-convex layer, so that the light does not concentrate on a specific part of the decorative layer. It is.

  In comparison between Sample 3, Sample 5 and Sample 6, it was found that uneven illumination can be reduced by first providing a white layer. Secondly, it was found that the illumination unevenness can be greatly reduced by providing the white layer on the pusher sheet rather than providing it on the surface of the decorative layer. About the 1st effect, it seems that it is because the light reflected on the side surface of a pusher repeats irregular reflection in a white layer, and it becomes difficult for light to concentrate on the specific site | part of a decoration layer. The second effect is considered as follows. Unlike the sample 6, the sample 5 has a gap between the white layer and the decorative layer. That is, it is considered that the illumination unevenness can be more effectively reduced by providing a distance for diffusing light emitted from the white layer over a wider range.

  Regarding the comparison between the sample 7 and the sample 1, it is considered that the uneven illumination is more effectively reduced in the sample 1 because of the same relationship as the relationship between the sample 6 and the sample 5.

  In comparison between sample 1 and sample 2, the degree of reduction in illumination unevenness was similar, but sample 1 appeared to have slightly less illumination unevenness. This seems to be because, in Sample 1 having no double-sided tape, slight irregular reflection occurred on the surface of the decorative layer and the surface of the white layer, and the uneven illumination was slightly reduced.

Experimental example 2:
Samples having the same configuration as Sample 1 of Experimental Example 1 except for the arithmetic average surface roughness Ra of the surface of the pusher were produced, and the ease of seeing uneven illumination by the pusher was evaluated. The arithmetic average surface roughness Ra was adjusted by changing the blasting roughness of the mold. In this sample, the height of the pusher is 0.26 mm, the diameter of the pusher is 1.5 mm, and the inclination angle of the side surface of the pusher is 85 °.

  From the results of the evaluation of the uneven illumination of Sample 1 and Sample 8 to Sample 11, it was found that the uneven illumination was reduced in the sample having an arithmetic average surface roughness value of Ra = 1.40 μm or more. Further, it was found that when Ra = 1.55 or more, uneven illumination is particularly difficult to see.

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

1 Keypad (first embodiment of decorative illumination member)
2 Key sheet (exterior material)
3 Pusher sheet (interior member)
4 Double-sided tape 5 Base sheet 5a Upper surface 5b Lower surface 6 Key top 7 Decoration layer 7a Display element 7b Background portion 7c Illumination display portion 8 Base sheet 8a Upper surface 8b Lower surface 9 Resin layer 10 containing light diffusing filler )
10a Fine uneven surface 10b Top surface 10c Side surface 11 Gap 12 Decorated molded body (second embodiment of decorated illumination member)
13 Outer molded body (exterior member)
13a Upper surface 13b Lower surface 14 Inner molded 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 (9)

In a decorative illuminating member having an illuminating display that illuminates with light from an internal light source,
A translucent exterior member provided with a decorative layer having the illumination display part;
The upper surface is disposed on the exterior member side, the lower surface is disposed on the internal light source side, and includes a translucent interior member having a concavo-convex surface portion at a position below the illumination display portion on the lower surface,
The decorative illuminating member, wherein the surface of the uneven surface portion is a fine uneven surface.
The decorative illuminating member according to claim 1, further comprising a resin layer including a light diffusing filler at a position below the illumination display unit.
The decorative illuminating member according to claim 2, wherein the transmittance of the uneven surface portion is higher than the transmittance of the resin layer.
The decorative illuminating member according to claim 2 or 3, wherein the resin layer is provided on a surface of the interior member facing the exterior member.
The decorative illuminating member according to any one of claims 2 to 4, wherein the resin layer is provided on a surface of the exterior member facing the interior member.
The decorative illuminating member according to any one of claims 1 to 5, wherein a gap formed by an air layer is provided between the exterior member and the interior member.
The decorative illuminating member according to any one of claims 1 to 5, further comprising a translucent adhesive layer for attaching the exterior member and the interior member.
The exterior member is an input operation sheet made of a resin film having a decorative layer in which a display element of characters, numbers, symbols or figures and a background part thereof are formed as the illumination display part,
The decorative illumination member according to any one of claims 1 to 7, 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 a decorative layer in which a display element of characters, numbers, symbols or figures and a background portion thereof are formed as the illumination display section,
The decorative illuminating member according to any one of claims 1 to 7, 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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