Title of Invention

"AN ILLUMINATION KEY"

Abstract

An illumination key is constructed from a key top (2) made of light-permeable resin, a film having a printed pattern (character) (4) formed in one side thereof, the film being heat fused to the top and side surfaces of the key top and cut away from the lower periphery of the side surfaces of the key top, and a key operating portion (la) made of light-permeable silicon rubber which is fixed to the underside surface of the key top by means of an adhesive (3).

Full Text

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an illumination key for use in various mobile communication devices, such as cellular phones and automobile phones, and various terminal devices, such as electronic organizers and the like, to enable the keys thereof to be visible in nighttime and low light conditions. This application is divided out of Indian Patent Application Uo,tJS/CAh/98t Description of the Prior Art In the prior art, because prior art il lumination keys are not designated to allow for reduction in size and weight of the key unit when manufacturing thin key tops, it is not possible to meet the market needs for ultralight keytops. Moreover, because the printed pattern (character) layer is formed in the underside surface of the light-permeable resin key top, the printed pattern (character) is difficult to see in the illumination key described above in the case where the upper surface of the key top has a curved shape. Moreover, in the case where a printed pattern (characters) is formed on one side of a film which is placed over a plurality of light-permeable resin key tops and heat fused to the upper and side surfaces thereof, because the key tops are connected to each other via the film, misoperations can occur when the operation of one key top also operates a neighboring key top. Further, when designing a lightweight keytop, it is difficult to adequately bond the keytop and the key operating portion. 1A SUMMARY OF THE INVENTION With a view towards overcoming the problems of the prior art discussed above, it is an object of the present invention to provide an illumination key which makes it possible to reliably recognize a printed pattern (character) even when the upper surface of the key top is slanted or curved, in which a key operating portion is given a rubber-like click sensitivity and a rubber-like elasticity, the key top portion is made from a rigid resin, and a reliably strong bond is created between the key operating portion and the key top. Furthermore, it is an object of the present invention to provide an illumination key that can reliable achieve ON/OFF operations while making it possible to reduce the weight of the keytop without reducing the bonding strength between the keytop and the key operating portion. Accordingly, the present invention provides an illumination key, comprising: a partial transmission white-colored membrane or colored partial transmission type light reflecting membrane formed on an upper surface of the transparent resin key top excluding the underside surface of the key top; a pattern formed on an upper surface of the partial transmission type light reflecting membrane; an opaque layer covered the upper and side surfaces of the key top excluding the pattern formed portion; a transparent protection layer formed on the upper and side surfaces of the opaque layer; and an upper surface of the key operating portion made from a transparent rubber or thermoplastic elastomer being fixed to the underside surface of the key top by means of a transparent adhesive such as herein described. 2 Further, in the illumination key according to the present invention, it is possible to form a light reflection layer having a white color or the like on all surfaces excluding the underside surface of the light-permeable resin key top, with the printed pattern (character) layer being formed in the upper surface of such reflection layer. In this case, except for the printed pattern (character) portion, an opaque layer is provided to cover the upper and side surfaces of the key top, with the upper and side surfaces of the opaque layer being covered by a transparent protection layer. And as before, an adhesive is used to fix the underside surface of the key top to the upper surface of a key operating portion made of light-permeable silicon rubber or thermoplastic elastomer-Further, in the illumination key according to the present invention, it is possible to use a thin key top made from a white-colored resin or the like, with the printed pattern (character) being formed on a surface of the key top which excludes the underside thereof. In this case, except for the printed pattern (character) portion, an opaque layer is provided to cover the upper and side surfaces of the key top, with the upper and side surfaces of the opaque layer being covered by a transparent protection layer. And as before, an adhesive is used to fix the underside surface of the key top to the upper surface of a key operating portion made of light-permeable silicon rubber or thermoplastic elastomer. Further, in the illumination key according to the present invention, it is possible to use a thin key top made from a white-colored or a colored partial light-permeable resin, with the printed pattern (character) being formed on a surface of the key top which excludes the underside thereof. And as before, a transparent adhesive is used to fix the underside surface of the key top to the upper surface of a key operating portion made of light-permeable silicon rubber or thermoplastic elastomer. In the illumination key according to the present invention, an operating shaft is formed at a central portion of the underside of a transparent resin key top mounted and bonded on top of a key operating portion formed from a transparent rubber or thermoplastic elastomer, and a cavity portion is formed in the underside of the keytops in order to make the keytop thinner. Further, the transparent resin keytop formed with the operating shaft is formed from a hard foaming resin such as polyurethane foam. Furthermore, the lower portion of the operation shaft of the transparent res in keytop described in Claim 3 is fitted intoa concave portion formed in a central upper surface portion of the transparent rubber or thermoplastic elastomer key operating portion, with such fitting portion being bonded by a transparent adhesive. Further, in the illumination key according to the present invention, a protruding portion is formed at the central upper surface portion of the transparent rubber or thermoplastic elastomer key operating port ion, 3 and also formed in such central portion is an insertion hole into which is fitted the operating shaft of the transparent resin keytop described in Claim 3, with such fitting portion being bonded by a transparent adhesive. Further, in the illumination key according to the present invention, an annular erect flange is formed near the outer periphery of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion, and the outer circumferential surface of the annular erect flange is bonded by means of an adhesive to a contact surface of the outer peripherial surface of the inside of the cavity portion of the transparent resin keytop described in Claim 3. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 is a cross-sectional schematic view of one embodiment of the present invention. Fig. 2(a) is a cross-sectional schematic view of another embodiment of the present invention. Fig. 2(b) is a cross-sectional schematic view of another embodiment of the present invention. Fig. 3 is a schematic cross-sectional view of another embodiment of the present invention. Fig. 4 is a schematic cross-sectional view of another embodiment of the present invention. Fig. 5(a) is a schematic cross-sectional view of a weight-reducing structure according to one embodiment of the present invention. Fig. 5(b) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the 4 present invention. Fig. 6(a) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 6(b) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 7(a) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 7(b) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 8(a) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 8(b) is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. Fig. 9 is a schematic cross-sectional view of a weight-reducing structure according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description of a preferred embodiment of the present invention will now be given below. As shown in the drawings, a light-permeable key pad I has an operating portion la and a non-operating portion lb connected to the operating portion la formed as an integral body from transparent si 1 icon rubber, other transparent rubber or transparent 5 thermopoastic elastomer such as vinyl chloride based elastomer, polyolefin base elastomer, polysterene-polybutadiene copolymer thermoplastic elastomer, ethylene vinyl acetate elastomer, chlorinated polyethylene elastomer, polyurethane rubber. By forming the keypad 1 from rubber or a thermoplastic elastomer, it is possible to utilize the rubber-like characteristics to obtain click-sens itivi ty and rapid operation sensitivity with the operating portion la. Further, in addition to the case in which the operating portion la is formed from a thin skirt portion lc, which rises up along a slant from the lower portion of the side surface of the non-operating portion lb, and a key top support portion Id which is integrally supported at the upper portion of the skirt portion lc, it is possible to construct the operating portion la in which forms the erect thin skirt portion lb toward the upper slanting portion thereof, or, the slanting skirt portion is eliminated and the key top supporting portion Id extends out horizontally from a thick side surface of the non~operating portion lb. In this connection, it should be noted that the present invention is not limited to these structures, and it is possible to utilize any other structure so long as it is possible to support a key top 2. In the case where a skirt portion lc is provided, this skirt portion lc carries out a click action. Further, the operating portion la is arranged above a substrate (not shown in the drawings) at a position corresponding to a fixed contact point on the substrate, with a rubber click structure being created by forming an electrically conductive contact member on the underside of the operating portion la, or with a dome click structure being created by means of a metal dome switch (not shown in the drawings). The key top 2, made from a thermoplastic resin such as ABS, polycarbonate, acrylic resin, is fixedly mounted to the top of the key top support portion Id by means of a tranparent adhesive 3. In this connection, the upper surface of the key top 2 may have any of a variety of shapes, such as a curved shape which slants in one 6 direction, for example. Further, the lower portion of the key top 2 may be formed to include a brim portion 2a, as shown in Fig. 1, or the lower portion of the key top 2 may be formed without such a brim portion. In general, to enable light to pass through the key top 2, a transparent or translucent material around lmm thick (e.g., in the range 0.8mm - 1.5mm) is used to make the key top 2, and in this regard it is possible to use a white-colored material which allows light at a certain intensity to pass therethrough. In the case where the key top 2 is formed from such white-colored material, there is no need to form the partial transmission light reflecting membrane 4a described below. The adhesive 3 is an adhesive used to bond the key top 2, made of a thermoplastic resin such as ABS, polycarbonate, acrylic resin, with the silicon key pad 1, made of a silicon rubber or other rubber material or thermoplastic elastomer, which is an integral body formed from the operating portion la and the non-operating portion lb. In this connection, the adhesive 3 may be any adhesive which makes it possible to bind two different materials together; for example, it is possible to use a silicon type adhesive in the case of silicon rubber. Further, with the exception of the underside surface, a printed pattern (character) layer 4 is formed in the surface of the key top using any of the methods described below. In one method, a partial transmission light reflecting membrane 4a having a bright color to reflect white light and the like is formed on all surfaces the light permeable resin key top 2 except for the underside surface thereof. For example, it is possible to use a white coating as the light reflect ing membrane. Next, a solid chromatic color printing is carried out in red, blue, yellow or the like to form a pattern comprised of letters, symbols, figures, with all of the solid printing 4b except for the portion containing the pattern being covered by a black opaque membrane 4c. Further, the opaque membrane 4c and the portion of the solid printing 4b which 7 contains the pattern (character or the like) is covered by a transparent protective membrane 5 formed from an acrylic resin such as urethane. Further, in the case where the body of the resin key top 2 is formed to have a thickness around lmm, i t is possible to use the above method to form a printed pattern (character) layer 4 without having to apply a white-colored coating to the surface of the key top 2 so long as it is possible for the body of the key top 2 to reflect white light and the like and at the same time allow light at a certain intensity to pass therethrough. Then, after forming the printed pattern layer 4 in the upper surface of the key top 2, the underside surface of the key top 2 is fixed to the upper surface of a key operating portion la of a key pad 1 by means of the transparent adhesive 3. Next, the means for making the illumination key ultralight will be described. As is structurally shown in Fig. 5-8, an operating shaft 9 is integrally formed at a central portion of the underside of the transplarent keytop 2 which is mounted and bonded to the top of the trasnparent rubber or thermoplastic elasltomer key operating portion lb. Further, a cavity 10 for making a thin keytop 2 is carved out to form a circular space to receive the operating shaft 9 of the underside of the keytop 2. Further, the thickness of the underside of the keytop 2 should have roughly the same thickness structure. The material used for the keytop 2 should be chosen so as to prevent the keytop 2 from being indented when the keytop 2 is struck by a finger. Of course, the contact surfaces of the keytop 2 and the key operating portion la are fixed by means of a transparent adhesive. By forming the operating shaft 9 on the underside of the keytop 2, it is possible to guarantee reliable ON/OFF operations of the key operating portion lb when the keytop 2 is pressed with a finger. 8 When select ing a material for the keytop 2, in order to achieve an even higher reduction in weight, the transparent resin keytop 2 shown in Fig. 7 should preferable be formed from a hard foaming resin such as polyurethane foam. In order to vastly improve the bonding strength when fixing the contact surfaces of the keytop 2 and the key operating portion la by means of a transparent adhesive 3, the lower portion of the operating shaft 9 of the transparent resin keytop 2 is fitted into the concave portion lg formed in the central upper portion of the transparent rubber or thermoplastic elastomer key operating portion la. In this way, because a vertical bonding is carried out on the fitting portion 11 of the lower portion of the operating shaft 9 fitted into the concave portion lg, it is possible to achieve an increase in bonding strength several times higher compared to horizontal bonding. To further increase the bonding strength, a protruding portion le as shown in Fig. 8 is formed on a central portion of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion lb, and an insertion hole If is formed in the central portion of the protruding portion le into which the operating shaft 9 of the transparent resinkeytop 2 fitted and vertically bonded by the applications of a transparent adhesive. In Fig. 8, the number 12 indicates a PET or a metal dome swi tch. Further, as shown in Fig. 9, an annular erect flange 13 is formed near the outer periphery of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion lb, and the outer circumferential surface of the annular erect flange 13 is bonded by means of an adhesive to a contact surface of the outer peripherial surface of the inside of the cavity portion 10 of the transparent resin keytop 2, whereby it becomes possible to maintain a sufficient bonding strength while at the same time achieving a reduction in weight. Further, it is possible to use or not use an 9 adhesive when fitting the lower portion of the operating shaft 9 into the concave portion of the central portion of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion lb. Now, by having the structure described above, the illumination key according to the present invention makes it possible to reliable recognize the character (pattern) on the key top 2 even when the upper surface of the key top 2 has a curved or slanting shape. Furthermore, because the key operating portion creates a rubber-like click sensitivity and a rubber-like elasticity while the resin of the key top portion is made rigid, and because it is possible to reliably achieve a strong bond between the key operating portion and the key top, the illumination key according to the present invention makes it possible to reliably carry out key operations by preventing misoperations and other problems such as peeling. Consequently, the present invention makes it possible to easily and cheaply provide an illumination key and a method of manufacturing such i llumination key, in which a key operating portion is given a rubber-likeclicksensitivity and a rubber-like elasticity, the key top portion is made from a rigid resin, and a reliably strong bond is created between the key operating portion and the key top. In particular, the structure described above makes the illumination key according to the present invention suitable for use in thin-type devices such as cellular phones and the like. Further, because the lower portion of the operating shaft of the keytop is fitted into the concave portion formed in the central portion of the upper surface of the key operating portion when the contact surfaces of the keytop and key operating portion are bonded together, it is possible to carry out a vertical bonding, and this makes it possible to improve the bonding strength by several times in addition to that achieved by horizontal bonding, whereby it becomes possible to increase the bonding strength for a small amount of contact surface. Furthermore, by forming a protruding portion 10 on the central portion of the upper surface of the key operating portion, and by fitting and bonding the operating shaft of the keytop into the insertion hole of such protruding portion, it is possible to achieve an even higher effective bonding. Further, in the present invention, by forming an operating shaft at the central portion of the underside of the keytop and a cavity around the periphery of such operating shaft, it becomes possible to make a thin keytop whereby it becomes possible to reduce the entire weight of the key. Furthermore, by forming the keytop from a hard foaming resin, it is possible to achieve an even higher reduction in weight while preventing the keytop from being indented when struck. Furthermore, an annular erect flange is formed near the outer periphery of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion, and the outer circumferential surface of the outer peripherial surface of the inside of the cavity portion of the transparent resin keytop, whereby it becomes possible to maintain a sufficient bonding strength while at the same time achieving a reduction in weight. Finally, it is to be understood that many changes and additions may be made to the embodiments described above without departing from the scope and spirit of the invention as defined in the appended Claims. 11 WE CLAIM: 1. An illumination key, comprising: a partial transmission white-colored membrane or colored partial transmission type light reflecting membrane (4a) formed on an upper surface of the transparent resin key top (2) excluding the underside surface of the key top (2); a pattern formed on an upper surface of the partial transmission type light reflecting membrane(4a); an opaque layer (4c) covered the upper and side surfaces of the key top (2) excluding the pattern formed portion; a transparent protection layer (5) formed on the upper and side surfaces of the opaque layer (4c); and an upper surface of the key operating portion (la) made from a transparent rubber or thermoplastic elastomer being fixed to the underside surface of the key top (2) by means of a transparent adhesive (3) such as herein described. 2. The illumination key as claimed in claim 1, wherein the transparent resin key top (2) is formed from a relatively thin key top made of white-colored resin or colored with partial transmission type light reflecting coloring agent, excluding the part of a partial transmission white-colored membrane or colored partial transmission type light reflecting membrane (4a). 3. The illumination key as claimed in Claim 1, wherein an operating shaft (9) is formed on a central portion of the underside of the keytop (2), and a cavity is formed on the underside of the keytop (2) to reduce the thickness of the keytop (2). 4. The illumination key as claimed in Claim 1, wherein the transparent resin keytop (2) is formed from a hard foaming resin such as polyurethane form. 12 5. The illumination key as claimed in Claim 1, wherein a lower portion of the operating shaft (9) of the transparent resin keytop (2) is fitted into a concave portion formed in a central portion of the upper surface of the transparent rubber or thermoplastic elastomer key operation portion (la), with such fitting portions being bonded by means of a transparent adhesive (3) such as herein described. 6. The illumination key as claimed in Claim 1, further comprising a protruding portion (le) formed at a central portion of the upper surface of the transparent rubber or thermoplastic elastomer key operating portion (la) and an insertion hole (If) formed in the protruding portion (le), wherein the operating shaft (9) of the transparent resin keytop (2) is fitted into the insertion hole (If) and bonded in place by means of a transparent adhesive (3) such as herein described. 7. An illumination key substantially as herein described, with particular reference to, and as illustrated in the accompanying drawings. x " Dated this 13th day of July, 2004. 13 An illumination key is constructed from a key top (2) made of light-permeable resin, a film having a printed pattern (character) (4) formed in one side thereof, the film being heat fused to the top and side surfaces of the key top and cut away from the lower periphery of the side surfaces of the key top, and a key operating portion (la) made of light-permeable silicon rubber which is fixed to the underside surface of the key top by means of an adhesive (3).

Documents:

00417-kol-2004 abstract.pdf

00417-kol-2004 claims.pdf

00417-kol-2004 correspondence.pdf

00417-kol-2004 description(complete).pdf

00417-kol-2004 drawings.pdf

00417-kol-2004 form-1.pdf

00417-kol-2004 form-18.pdf

00417-kol-2004 form-2.pdf

00417-kol-2004 form-3.pdf

00417-kol-2004 form-5.pdf

00417-kol-2004 g.p.a.pdf

00417-kol-2004 letters patent.pdf

00417-kol-2004 priority document others.pdf

00417-kol-2004 priority document.pdf

417-KOL-2004-CORRESPONDENCE 1.1.pdf

417-KOL-2004-CORRESPONDENCE-1.2.pdf

417-KOL-2004-FORM 27-1.1.pdf

417-KOL-2004-FORM 27.pdf

417-kol-2004-granted-abstract.pdf

417-kol-2004-granted-claims.pdf

417-kol-2004-granted-description (complete).pdf

417-kol-2004-granted-drawings.pdf

417-kol-2004-granted-form 2.pdf

417-kol-2004-granted-specification.pdf

417-kol-2004-priority document.pdf

417-kol-2004-translated copy of priority document.pdf