JP2003229036A - Metal-plating lighting type resin key top - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily-molded metal-plating lighting type resin key top allowing the efficient lighting of a display part, and having no factor impairing appearance of the display part. <P>SOLUTION: This metal-plating lighting type resin key top comprises an outer molded body part 1 of an synthetic resin plated with a metal, and an inner molded body part 2 of a translucent synthetic resin not plated with a metal. The outer face of the outer molded body part 1 is plated with a metal layer 5, a top face 3 is formed with the display part 6, the key top is mounted on a translucent key sheet 11 for use, and illumination light irradiated from the lower face side of the key sheet 11 can be irradiated on the display part 6. At least the whole top face 3 is plated with the metal layer 5, while a part of the inner molded body part 2 is exposed to a side-face side to form a lighting part 8. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a resin key top used for an input push-button switch in an electronic device such as a portable information terminal or an AV device, and particularly to a display portion thereof. The present invention relates to an illuminated resin keytop capable of providing illumination. 2. Description of the Related Art For an input push button switch (key) in an electronic device such as a portable information terminal, a resin key top is used because of a good operational feeling and a wide variety of designs. The key sheet mounted thereon is often used as a cover member. Among them, a resin key top is formed by injection molding of a thermoplastic resin into a structure having a top surface and side surfaces, and a display portion provided with characters or symbols indicating operation functions on the top surface is provided. is there. On the other hand, many key sheets are formed of a rubber-like elastic body such as synthetic rubber or thermoplastic elastomer, or formed of a flexible resin film. The resin key top is fixedly mounted on the key sheet with an adhesive. [0003] Among such resin key tops, there is an illuminated type in which an illuminating light emitted from a lower surface side of a key sheet illuminates a display portion thereof. On the other hand, recently, there has been an increasing demand for a metal-plated resin key top which has a high-grade appearance by forming a metal layer on the outer surface thereof by plating. And with this, one problem was invited. That is, since the transmission of light is hindered by the metal layer, it is impossible to illuminate the display unit effectively. [0004] As a resin key top to cope with this problem, there is a resin key top formed by two-color molding of a synthetic resin plated with metal and a light-transmitting synthetic resin not plated with metal.
FIGS. 17 and 18 show typical examples of the conventional structure. As shown in the figure, a conventional metal-plated illuminated resin keytop formed by two-color molding is made of a translucent synthetic resin in which no metal is plated inside an outer molded body 101 made of a synthetic resin in which metal is plated. The inner molded body 102 is combined to form a structure having a top surface 103 and a side surface 104, and a metal layer 105 is formed on the outer surface of the outer molded body 101.
Are formed by plating. And the top surface 10
In FIG. 3, a part of the inner molded body 102 is exposed to form an illuminating portion 102i.
The display unit 106 (FIG. 18) in FIG. 3 can be illuminated. The above-mentioned conventional metal-plated illuminated resin key top as described above can achieve both the decoration by the metal layer and the illumination of the display unit, but still has a problem. . It is the top surface 103, that is, the display unit 10
This is a problem caused by two-color molding in which a part of the inner molded body 102 is exposed in FIG. One of the problems is that such two-color molding complicates the structure of the mold, making molding difficult and increasing the cost. The other one is that these characters and symbols are attached in a state where the metal layer is removed so that characters and symbols for operation functions attached to the display unit 106 can be illuminated by the illumination unit 102i. The problem is that they may look bad. If the display section 106 is given a numeral "1", for example, as shown in FIG. 19, there is no problem since it can be formed only by continuously removing the metal layer. However, when a numeral “8” is added as shown in FIG. 20, the island-like portion 107 remains inside the metal layer. Here, the plating process for forming the metal layer 105 is performed by first forming a thin base metal layer by electroless plating, and then performing electrolytic plating using the base metal layer as a conductor. Therefore, it is necessary to provide a bridge portion 108 for energizing the island portion 107, and this bridge portion 10
8 was a factor that reduced the appearance. The present invention has been made on the background of the prior art, and is capable of efficiently illuminating the display unit, has no factors that impair the appearance of the display unit, and is easy to mold. The purpose is to provide an illuminated resin key top of plating type. According to the present invention, in order to achieve the above object, an inner molded body made of a light-transmitting synthetic resin which is not plated with metal is provided inside an outer molded body made of a synthetic resin plated with metal. The body part is combined to form a structure having a top surface and side surfaces, and a metal layer is plated on the outer surface of the outer molded body part, and characters or symbols for operation functions are attached to the top surface. An illumination unit for illuminating the display unit is provided on the second molded body unit, and is used by being mounted on a translucent key sheet covering a push button switch, A metal-plated illuminated resin key that is illuminated from the lower surface side of the key sheet so that the illumination light can be emitted from the illuminating portion by passing through the second molded body portion to illuminate the display portion. About the top,
While plating a metal layer on at least the entire top surface,
The illuminating unit is formed by exposing a part of the inner molded body to the side surface. An embodiment of the present invention will be described below. 1 to 4 show a metal-plated illuminated resin keytop according to a first embodiment. As can be seen in FIG. 1, the metal-plated illuminated resin keytop in this embodiment is an outer molded body 1 made of a synthetic resin plated with metal.
And an inner molded body 2 made of a light-transmitting synthetic resin that is not plated with metal. By combining the two so that the inner molded body 2 is wrapped by the outer molded body 1, a structure having a top surface 3 and side surfaces 4 is obtained. Is formed. The outer molded body 1 has a metal layer 5 formed by plating so as to cover the entire outer surface of the outer molded body 1 and a display unit 6 having characters and symbols for operating functions attached to the top surface 3 thereof. FIG. 2) is provided. On the other hand, the inner molded body 2 is provided at its lower end with a flange 7 projecting in the lateral direction.
The light is exposed to the illumination section 8. As shown in FIG. 3, a part of the outer molded body 1 partially penetrates into the illuminating section 8 provided by the flange 7, as shown in FIG. 3. This relates to a method of manufacturing a metal plating type illuminated resin key top. That is, the outer molded body part 1 and the inner molded body part 2 are generally formed by injection molding using two colors of a synthetic resin plated with a metal and a translucent synthetic resin not plated with a metal. In general, a plurality of molded bodies composed of the outer molded body part 1 and the inner molded body part 2 are injection-molded simultaneously. Then, the plating process for plating the metal layer 5 is performed in a state where the plurality of molded bodies are connected by a runner at the time of injection molding. In this case, the plurality of molded bodies are collectively formed into a plurality of molded bodies through the runner. The plating process can be performed efficiently when the power is supplied. For such a reason, when a runner is provided in the flange portion 7, a part of the outer molded body portion 1 partially penetrates into the runner portion so that power can be supplied through the runner. is there. Generally, it is appropriate to provide a runner at the lower end portion of the side surface (the flange 7 in this example), but it is also possible to provide the runner at another portion, for example, the back side of the top surface. In that case, it is not necessary to adopt the structure as shown in FIG. Therefore, the display unit 6 can be efficiently illuminated by the illumination from the side. Here, the synthetic resin on which the metal for the outer molded part 1 is plated, more specifically, the synthetic resin on which the metal can be plated by electroless plating, is, for example, acrylonitrile-butadiene-styrene (ABS). )resin,
Polypropylene (PP) resin, polyphenylene oxide (PPO) resin, polyacetal (POM) resin, polyimide resin, polysulfone resin, and the like can be preferably used, and alloy resins of the above resins and alloys of polycarbonate (PC) resin can be used. Resins and their modified resins can also be used as preferable ones. On the other hand, the translucent synthetic resin that is not plated with metal for the inner molded body 2 includes, for example, polymethyl methacrylate (PMMA) resin, polystyrene (PS) resin,
Acrylonitrile / styrene copolymer (AS), methyl methacrylate / styrene copolymer (MS), polycarbonate (PC) resin, polyethylene (PE) resin,
Crystalline polyolefin-based resins, polycyclic norbornene-based methacrylate resins, and the like can be preferably used. FIGS. 5 and 6 show a state in which the metal-plated illuminated resin keytop according to the present embodiment is incorporated in a housing. The illuminated resin key top is mounted on a key sheet 11 made of, for example, translucent silicone rubber, which covers a push button switch (not shown) by being fixed with, for example, a UV-curable adhesive 12, and It is incorporated such that the side surface 4 is surrounded by the housing 13. In the state of FIG. 5, when illumination light is irradiated from the lower surface side of the key sheet 11, the illumination light is emitted from the illumination unit 8 by passing through the translucent inner molded body 2, and the emitted light is The display unit 6 on the top surface 3 is efficiently illuminated from the surroundings through a gap between the housing 13 and the housing 13. For this reason, in the metal plating type illuminated resin key top according to the present invention, even if the metal layer 5 having no translucency is formed on the entire top surface 3, the display section 6 is raised brightly by the illumination. The visibility can be improved. As a result, the top surface 3, that is, the display section 6, can be formed only by the outer molded body 1 made of a synthetic resin plated with a metal, and can be formed without complicating a mold and making molding difficult. Costly two-color molding becomes possible. Further, since the metal layer 5 can be plated on the entire surface of the display section 6, it is possible to avoid a factor that impairs the appearance, which has conventionally been a problem. Further, as in the present embodiment, the flange 7 is provided on the inner molded body 2, and only the flange 7 is exposed on the side surface 4 to form the illumination unit 8. Has the advantage that it can be made wider. FIGS. 7 to 10 show a metal-plated illuminated resin keytop according to a second embodiment. The metal-plated illuminated resin keytop in the present embodiment is formed by combining an outer molded body portion 21 made of a synthetic resin plated with metal and an inner molded body portion 22 made of a light-transmitting synthetic resin not plated with metal so as to vertically overlap. , And has a top surface 23 and a side surface 24. The outer molded body 21 is covered with the metal layer 2 by plating so as to cover the entire outer surface.
5, and a display section 26 (FIG. 8) on the top surface 23 of which characters and symbols for operation functions are provided. In the present embodiment, the outer molded body 21 and the inner molded body 22 are vertically overlapped. Therefore, the inner molded body 22 is provided with the flange 2 provided at the lower end thereof.
Almost the entire side surface including the side 7 is exposed to the side surface 24, so that the illuminating portion 28 having a larger area than in the first embodiment can be formed. For the same reason as described in the first embodiment, a part of the outer molded body portion 21 partially penetrates into the illuminating portion 28 for the same reason as described in the first embodiment (FIG. 9). FIG. 11 shows a state in which the metal-plated illuminated resin keytop according to the present embodiment is incorporated in a housing. The structure is basically the same as in the first embodiment. That is, it is mounted on the translucent key sheet 11 by being fixed with the adhesive 12, and is assembled so that the side surface 24 is surrounded by the housing 13. In the state of FIG. 11, when illumination light is irradiated from the lower surface side of the key sheet 11, the illumination light passes through the translucent inner molded body portion 22 and is emitted from the illumination portion 28. The emitted light efficiently illuminates the display unit 26 of the top surface 23 from the surroundings through a gap between the housing 13 and the light. In particular, in the present embodiment, the illuminating portion 28 covers almost the entire side surface of the inner molded body portion 22.
Is formed, it is possible to illuminate the display unit 26 even more efficiently. Accordingly, the same effect as that described in the first embodiment can be obtained. FIGS. 12 to 15 show a metal-plated illuminated resin key top according to a third embodiment, and FIG. 16 shows a state in which the key top is assembled in a housing. The metal-plated illuminated resin key top in the present embodiment has an inner molded body portion 32.
Is only slightly different from that of the inner molded body part 22 in the second embodiment. Specifically, the side surface of the inner molded body 32 is formed flat from the upper end to the lower end. That is, the inner formed body 32 has a shape in which the flange 27 provided in the inner formed body 22 in the second embodiment is omitted. Here, when this embodiment is compared with the second embodiment, the inner molded body portion 22 having the flange portion 27
It can be said that the illumination efficiency can be further improved.
However, the illuminating portion 38 formed on almost the entire side surface of the inner molded body portion 32 has a sufficient illuminating ability, and even if the flange portion is omitted, the required illuminating function can be satisfied. By omitting the flange, there is an advantage that the mold structure can be simplified. Other configurations and effects are the same as those of the second embodiment, and thus the same reference numerals are given to the common portions, and the description thereof will be omitted. According to the present invention, the illuminating portion is formed by exposing a part of the inner molded body to the side surface. Therefore, according to the present invention, even when the metal layer is formed on the entire top surface, the display section can be efficiently illuminated. As a result, the top surface can be formed only of the outer molded body made of a synthetic resin plated with metal, and low-cost two-color molding can be performed without complicating the mold and making molding difficult. It becomes. In addition, since a metal layer can be plated on the entire surface of the display unit, it is possible to avoid a factor that impairs appearance, which has been a problem in the related art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view taken along line SA-SA in FIG. 2 of a metal-plated illuminated resin keytop according to a first embodiment of the present invention. FIG. 2 is a plan view of an illuminated resin keytop of a metal plating type according to the first embodiment. FIG. 3 is a right side view of an illuminated resin keytop of a metal plating type according to the first embodiment. FIG. 4 is a left side view of an illuminated resin keytop of a metal plating type according to the first embodiment. FIG. 5 is a sectional view showing a state in which the metal-plated illuminated resin keytop according to the first embodiment is incorporated in a housing. FIG. 6 is a plan view showing a state in which a metal-plated illuminated resin keytop according to the first embodiment is incorporated in a housing. FIG. 7 is a cross-sectional view of the metal-plated illuminated resin keytop according to the second embodiment, taken along line SB-SB in FIG. 8; FIG. 8 is a plan view of an illuminated resin keytop of a metal plating type according to a second embodiment. FIG. 9 is a right side view of an illuminated resin keytop of a metal plating type according to a second embodiment. FIG. 10 is a left side view of an illuminated resin keytop of a metal plating type according to a second embodiment. FIG. 11 is a cross-sectional view illustrating a state in which a metal-plated illuminated resin keytop according to a second embodiment is incorporated in a housing. FIG. 12 is a cross-sectional view of a metal-plated illuminated resin keytop according to a third embodiment, taken along line SC-SC in FIG. 13; FIG. 13 is a plan view of an illuminated resin keytop of a metal plating type according to a third embodiment. FIG. 14 is a right side view of an illuminated resin keytop of a metal plating type according to a third embodiment. FIG. 15 is a left side view of an illuminated resin keytop of a metal plating type according to a third embodiment. FIG. 16 is a cross-sectional view of a state in which a metal-plated illuminated resin keytop according to a third embodiment is incorporated in a housing. FIG. 17 is a cross-sectional view of a conventional metal-plated illuminated resin keytop. FIG. 18 is a plan view of a conventional metal-plated illuminated resin keytop. FIG. 19 is an explanatory view of a display unit of a conventional metal-plated illuminated resin keytop. FIG. 20 is an explanatory view of another example of a display unit of a conventional metal-plated illuminated resin keytop. [Description of Signs] 1 outer molded body part 2 inner molded body part 3 top surface 4 side surface 5 metal layer 6 display unit 8 illumination unit 11 key sheet 21 outer molded body part 22 inner molded body part 23 top surface 24 side surface 25 metal layer 26 display part 28 illuminating part 32 inner molded part 38 illuminating part

Claims (1)

[Claim 1] An inner molded body made of a light-transmitting synthetic resin that is not plated with metal is combined with an inner molded body made of a synthetic resin that is plated with metal and has a top surface and side surfaces. In addition to being formed into a structure, a metal layer is plated on the outer surface of the outer molded body, and a display unit representing characters and symbols for operation functions is provided on the top surface, and further illuminates the display unit. An illuminating section is provided on the second molded body section, and is used by being mounted on a translucent key sheet that covers the push button switch, and illuminating light emitted from the lower side of the key sheet is used. In a metal-plated illuminated resin keytop, which is capable of emitting light from the illuminating portion and illuminating the display portion by transmitting through the second molded body portion, a metal layer is plated on at least the entire top surface. While doing
The illuminated portion is formed by exposing a part of the inner molded body portion to the side surface.