Method for manufacturing light emitting metal knob

The present invention relates to a method for manufacturing a light emitting knob based on a novel process that is capable of preventing a letter that is separated from a light blocking metal plate at a display window forming step from being separated from a resin layer irrespective of the shape or the type of the letter, which constitutes a light emitting display window, thereby considerably reducing a defect rate, and in particular, to provide a method for manufacturing a light emitting metal knob that introduces a new process so as to realize a surface color through anodizing processing from letters separated from a light blocking metal plate.

FIELD OF THE INVENTION

The present invention relates to a method for manufacturing a light emitting metal knob that emits light emitted from a light emitting device outward through a letter or symbol type light emitting display window, thereby improving visibility.

BACKGROUND OF THE INVENTION

In general, a knob, which has the same dictionary definition as a protruding handle, is a button that is configured to display or control a vehicle or an electronic product. Knobs may have various shapes, structures, and functions. For example, knobs are classified into a display type knob, such as a change knob of a transmission gear of a vehicle, a push type knob, such as a start button of a vehicle, or a rotary type knob, such as a volume adjustment knob of an audio system.

Conventionally, a synthetic resin was simply molded in order to manufacture the knob. In recent years, knobs having luxurious and aesthetically pleasing appearances have been proposed with increasing interest in the design of knobs. For example, a light emitting adjustment knob is disclosed in Korean Registered Patent Publication No. 10-1210906. As shown inFIGS. 1 and 2, a light emitting metal knob1includes a light blocking metal plate10having a light emitting display window11and a resin layer20, made of a light transmitting synthetic resin, coupled to the lower surface of the light blocking metal plate10.

The resin layer20is coupled to the lower part of the light blocking metal plate10by bonding or by insert injection molding. In addition, referring toFIG. 2, a light emitting device30is installed under the resin layer20to display a predetermined message, such as “ENGINE START STOP,” outward through the light emitting display window11of the light blocking metal plate10in a light emitting fashion.

A method for manufacturing the conventional light emitting metal knob as described above will be described with reference toFIGS. 3 and 4. The method for manufacturing the conventional light emitting metal knob includes a metal plate processing step (S10) of processing a light blocking metal plate10such that the upper part of the light blocking metal plate is closed and the lower part of the light blocking metal plate is open, a resin layer coupling step (S20) of coupling a resin layer20, which is made of a light transmitting synthetic resin, to the inner side of the lower part of the light blocking metal plate10, a display window forming step (S30) of forming a light emitting display window11in the upper surface of the light blocking metal plate10by carving, a surface treatment step (S40) of treating the upper surface of the light blocking metal plate10, in which the light emitting display window11is formed, and a coating step (S50) of coating the treated upper surface of the light blocking metal plate10.

In the method for manufacturing the conventional light emitting metal knob, as shown inFIG. 5, letters, such as E, N, G, I, N, S, and T, the start and the end of a cutoff line of each of which are attached to the light blocking metal plate10, of “ENGINE START STOP,” which is the message, displayed through the light emitting display window11, which is widely used, are not separated from the resin layer20. However, the inner portions of letters, such as A, R, O, and P, which are separated from the light blocking metal plate10with the result that only the bottom surfaces of the letters are attached to the resin layer20, i.e. “Δ” of A, “D” of R and P, and “O” of O, are easily separated from the resin layer20when the light emitting display window11is formed by carving at the display window forming step (S30) and when the upper surface of the light blocking metal plate10is treated at the surface treatment step (S40), whereby a defect rate is increased.

In order to solve such a problem, the present applicant filed and registered a ‘method for manufacturing a light emitting knob’ in each of Korean Patent Registrations Nos. 10-1560998 and 10-1560999, thereby bringing about an effect of significantly reducing the defect rate.

But recently, anodizing treatment is required to realize a surface color of the light blocking metal plate10in order to provide a more aesthetic effect. However, according to the above-described related art, it is inevitable that the letters which are island parts are separated independently after forming the light emitting display window11by plane-cutting the upper surface of the light blocking metal plate10. Therefore, in the anodizing process, the island parts are separated from the light blocking metal plate10without being connected to the metal, so that only the island parts cannot be realized color.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method for manufacturing a light emitting metal knob based on a novel process that is capable of preventing a letter that is separated from a light blocking metal plate at a display window forming step from being separated from a resin layer irrespective of the shape or the type of the letter, which constitutes a light emitting display window, thereby considerably reducing a defect rate.

And in particular, to provide a method for manufacturing a light emitting metal knob that introduces a new process so as to realize a surface color through anodizing processing from letters separated from a light blocking metal plate.

Other objects, specific advantages, and novel features of the present invention will become apparent from the following description of embodiments given in conjunction with the accompanying drawing.

In order to accomplish the above objects, a method for manufacturing a light emitting metal knob according to the present invention includes a metal plate processing step of processing a light blocking metal plate such that an upper part of the light blocking metal plate is closed and a lower part of the light blocking metal plate is open; a display groove forming step of forming a light emitting display groove in an upper surface of the light blocking metal plate; a first resin layer coupling step of coupling a first resin layer, which is made of a light transmitting synthetic resin, to the upper surface of the light blocking metal plate so as to fill the light emitting display groove; an upper surface plane-cutting step of cutting the upper surface of the light blocking metal plate planarly so that the first resin layer filled in the light emitting display groove is left; an anodizing step of applying an anodic oxidation treatment to the surface of the light blocking metal plate and then absorbing an organic dye to realize color; a lower surface plane-cutting step of cutting a lower surface of the light blocking metal plate planarly such that the first resin layer coupled into the light emitting display groove is exposed from the lower surface of the light blocking metal plate to form a light emitting display window; and a second resin layer coupling step of coupling a second resin layer, which is made of a light transmitting synthetic resin, to the lower surface of the light blocking metal plate.

In addition, the metal plate processing step may include processing a plate-shaped metal material by pressing to manufacture the light blocking metal plate.

In addition, the method according to the present invention may further include a surface treatment step performing between the display groove forming step and the first resin layer coupling step, to surface-treat the light blocking metal plate to increase a coupling force of the first resin layer to the light blocking metal plate.

In addition, the surface treatment step may include treating a surface of the light blocking metal plate to increase the oxygen content to form an oxygen-containing film containing oxygen; and the first resin layer coupling step may include the first resin layer contains an additive compound having a functional group that reacts with the oxygen-containing film as a thermoplastic resin composition, wherein the additive compound is selected from the group consisting of a carboxyl group, a salt thereof and ester thereof, an epoxy group, a glycidyl group, an isocyanate group, a carbodiimide group, an amino group and a salt thereof, an acid anhydride group and an ester thereof.

In addition, the method according to the present invention may further include a sandblasting step performing between the upper surface plane-cutting step and the anodizing step, to sandblast a surface of the light blocking metal plate to make the surface clean.

In addition, the first resin layer coupling step may include the first resin layer is bonded to the upper surface of the light blocking metal plate or the first resin layer is insert injection molded by using the light blocking metal plate as an insert.

In addition, the second resin layer coupling step may include the second resin layer is bonded to the lower surface of the light blocking metal plate or the first resin layer is insert injection molded by using the light blocking metal plate as an insert.

In addition, the method according to the present invention may further include a coating step of coating the upper surface of the light blocking metal plate.

In addition, the coating step may include coating the upper surface of the light blocking metal plate with hard urethane.

The method for manufacturing the light emitting metal knob according to the present invention has the following effects.

First, the light emitting display groove is formed on the upper surface of the light blocking metal plate at the display groove forming step, and then the first resin layer is filled in the light emitting display groove at the first resin layer coupling step and the upper surface plane-cutting step, the letters to be separated from the light blocking metal plate is maintained in a state where the lower surface and the side surface are firmly coupled by the first resin layer and the second resing layer through the lower surface plane-cutting step and the second resin layer coupling step, thereby considerably reducing a defect rate.

Second, the first resin layer is coupled to the light emitting display groove through the upper surface plane-cutting step after the display groove forming step and the first resin layer coupling step, since the metal connection between the light blocking metal plate and the letters to be separated is maintained, thereby the color of the surface can be realized even the letters to be separated from the light blocking metal plate when the anodizing processing.

Third, an oxygen-containing film is formed on the surface of the light blocking metal plate through the surface treatment step and an additive compound having a functional group reactive with the oxygen-containing film is contained in the first resin layer at the first resin layer coupling step, thereby a strong coupling force between the two dissimilar materials can be obtained and there is an effect of preventing the first resin layer from being separated from the light blocking metal plate together with the letters to be separated.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an exemplary embodiment of a method for manufacturing a light emitting metal knob according to the present invention will be described in detail with reference to the accompanying drawings.

As shown inFIGS. 6 to 11, the method for manufacturing the light emitting knob according to the present invention may include a metal plate processing step (S100), a display groove forming step (S200), a first resin layer coupling step (S300), an upper surface plane-cutting step (S400), an anodizing step (S500), and a lower surface plane-cutting step (S600). As shown inFIG. 12, the method for manufacturing the light emitting metal knob according to the present invention may further include a surface treatment step (S250) and a sandblasting step (S450). As shown inFIG. 13, the method for manufacturing the light emitting metal knob according to the present invention may further include a coating step (S800).

At the metal plate processing step (S100), as shown inFIGS. 6 and 7, a light blocking metal plate100is processed such that the upper part of the light blocking metal plate100is closed and the lower part of the light blocking metal plate100is open. The light blocking metal plate100is made of a plate-shaped metal material. As compared with a conventional synthetic resin, the light blocking metal plate100has an aesthetically pleasing appearance due to the luxurious characteristics of metal. The light blocking metal plate100has various shapes based on the function and type of the light emitting metal knob1. As shown inFIG. 2, the upper part of the light blocking metal plate100is closed and the lower part of the light blocking metal plate100is open such that the light blocking metal plate100blocks light from the light emitting device30, which emits light under the light blocking metal plate100, and such that the lower part of the light blocking metal plate100is coupled to the light emitting device30. The light blocking metal plate100may be processed using various processing methods, such as cutting, casting, and injection molding, such that the upper part of the light blocking metal plate100is closed and the lower part of the light blocking metal plate100is open. As shown inFIG. 7, however, a plate-shaped metal material may be processed by pressing to manufacture the light blocking metal plate100, which is most suitable for mass production, considering that the light blocking metal plate100is made of a plate-shaped material.

At the display groove forming step (S200), as shown inFIGS. 6 to 8, a light emitting display groove110is formed in the upper surface of the light blocking metal plate100. In a case in which the light blocking metal plate100is configured such that the upper part of the light blocking metal plate100is closed and the lower part of the light blocking metal plate100is open, as shown inFIGS. 6 to 8, the light blocking metal plate100has a ‘[’ shape, in which the lower part of the light blocking metal plate100is open when viewed in side section. The light emitting display groove110is formed in the exposed upper surface of the light blocking metal plate100such that the light emitting display groove110has the same shape as a letter or a symbol of a light emitting display window120, which will be described hereinafter. As shown inFIGS. 7 and 8, carving may be used to form the light emitting display groove110in the upper surface of the light blocking metal plate100. Alternatively, various other processing methods, such as pressing, punching, and chemical hatching, may be used to form the light emitting display groove110in the upper surface of the light blocking metal plate100. Any processing methods may be used as long as, at the display groove forming step (S200), the light emitting display groove110is formed in the upper surface of the light blocking metal plate100such that the light emitting display groove110has the same shape as the light emitting display window120, which will be described hereinafter.

Meanwhile, it may seem that the display groove forming step (S200) is carried out after the metal plate processing step (S100) considering the order of the reference symbols or the sequence of the flowchart shown in the drawings. However, the sequence in which the metal plate processing step (S100) and the display groove forming step (S200) are carried out is not particularly restricted. That is, at the display groove forming step (S200), the light emitting display groove110may be formed in advance in a portion of the plate-shaped metal material which will become the upper surface of the light blocking metal plate100at the metal plate processing step (S100), and then the metal plate processing step (S100) may be carried out. Alternatively, the metal plate processing step (S100) and the display groove forming step (S200) may be simultaneously carried out such that the light blocking metal plate100is processed by pressing simultaneously when the light emitting display groove110is formed.

At the first resin layer coupling step (S300), as shown inFIGS. 6 and 7, a first resin layer200, which is made of a light transmitting synthetic resin, is coupled to the upper surface of the light blocking metal plate100so as to fill the light emitting display groove110. Since the first resin layer200is made of a light transmitting synthetic resin, light emitted from the light emitting device30may be transmitted through the first resin layer200such that the light reaches the light blocking metal plate100. In a case in which the first resin layer200is coupled to the upper surface of the light blocking metal plate100, the first resin layer200may be manufactured in advance so as to have a shape in which the first resin layer200can be inserted into and fitted in the light blocking metal plate100, and may then be coupled to the light blocking metal plate100by bonding. Alternatively, the first resin layer200may be formed by insert injection molding using the light blocking metal plate100as an insert such that the light blocking metal plate100is coupled to the first resin layer200.

At the upper surface plane-cutting step (S400), as shown inFIGS. 6, 7, and 9, the upper surface of the light blocking metal plate100is cut planarly so that the first resin layer200filled in the light emitting display groove110is left. The first resin layer200is coupled to the entire upper surface of the light blocking metal plate100in the first resin layer coupling step (S300). The upper surface of the light blocking metal plate100excluding the light emitting display groove110is cut planarly so that the exposed upper surface becomes a metal surface through the upper surface plane-cutting step (S400). Therefore, when the upper surface of the light blocking metal plate100is cut planarly, the first resin layer200filled in the light emitting display groove110as well as the letters to be separated is firmly coupled to the first resin layer200. In particular, the metal connection between the light blocking metal plate100and the letters to be separated is maintained.

At the anodizing step (S500), as shown inFIGS. 6 and 7, the surface of the light blocking metal plate100is applied an anodic oxidation treatment and then absorbed an organic dye to realize color. The anodizing treatment, that is, anodizing is performed by immersing the light blocking metal plate100as an anode in an aqueous solution of sulfuric acid, nitric acid, or the like, which is an electrolyte, and then flowing an electric current. Then oxygen is generated in the light blocking metal plate100by electrolysis, and this oxygen is oxidized to form an oxide film on the surface of the light blocking metal plate100. This oxide film does not dissolve even when exposed to solution and acid, thus protecting the metal. Further, when the organic dye is adsorbed on the thus formed oxide film, various desired colors can be expressed.

In this anodizing step (S500), since the light blocking metal plate100becomes an anode and a current should flow to the letters to be separated, the metal connection between the light blocking metal plate100and the letters to be separated should be maintained. Therefore, the grooves are formed so as not penetrate through the light emitting display groove110on the upper surface of the light blocking metal plate100, and after the first resin layer200is coupled to the light emitting display groove110in a state where the metal connection between the letters to be separated and the light blocking metal plate100is maintained, and then the upper surface plane-cutting step (S400) is performed so that the metal surface is exposed on the upper surface of the light blocking metal plate100.

The light emitting display groove110of the light blocking metal plate100having completed the anodizing process should be changed to the light emitting display window120so that the light is transmitted because the entire lower surface is still a metal surface. Therefore, At the lower surface plane-cutting step (S600), as shown inFIGS. 6, 7, and 10, the lower surface of the light blocking metal plate100is cut planarly such that the first resin layer200coupled into the light emitting display groove110is exposed from the lower surface of the light blocking metal plate100to form a light emitting display window120. That is, if the lower surface of the light emitting display groove110is blocked by the metal surface of the light blocking metal plate100, light emitted from the light emitting device30cannot emit upward from the light emitting display groove110. Therefore, when the lower surface of the light blocking metal plate100is cut planarly so that the closed lower surface of the light emitting display groove110is exposed, the light emitting display groove110is completely exposed upward and downward, as a hole or an opened window, so that the light emitting display window120is formed.

At this time, if the lower surface plane-cutting step (S600) is performed, the first resin layer200is exposed upward and downward so that light can be transmitted through the light emitting display window120. However, in this case, since the light emitting metal knob1is normally formed in a push-button type, a structure capable of supporting the lower surface of the first resin layer200is required, and the structure should be made of a light transmitting material.

To do this, At the second resin layer coupling step (S700), as shown inFIGS. 6 and 7, a second resin layer300, which is made of a light transmitting synthetic resin, is coupled to the lower surface of the light blocking metal plate100. Since the second resin layer300is also a light transmitting synthetic resin, light emitted from the light emitting device30can be transmitted to the outside. That is, light emitted from the light emitting device30passes through the second resin layer300and emits upward from the first resin layer200. When the second resin layer300is coupled to the lower surface of the light blocking metal plate100, first the second resin layer300is formed in advance so that the lower surface of the light blocking metal plate100can be inserted, or the second resin layer300may be insert injection-molded by using the light blocking metal plate100as an insert. The second resin layer300may be formed with a bracket, a protrusion, or a protruding groove, though it is not shown in the figure for coupling with another member in a lower portion.

Meanwhile, the surface treatment step (S250) is performed between the display groove forming step (S200) and the first resin layer coupling step (S300) as shown inFIG. 12. At the surface treatment step (S250), the light blocking metal plate100is surface-treated to increase a coupling force of the first resin layer200to the light blocking metal plate100. More specifically, as the surface treatment for increasing the coupling force of the first resin layer200by injection molding using the light blocking metal plate100made of a metal material as an insert, there is a mechanical insertion method by the concave and convex shapes, and the coupling force with the first resin layer200can be increased through a chemical treatment such as etching on the light blocking metal plate100made of a metal material.

In the present invention, an oxygen-containing film is formed on the surface of the light blocking metal plate100in order to maximize the coupling force between the light blocking metal plate100made of a metal material and the first resin layer200, by adding an additive compound having a functional group reactive with the oxygen-containing film, a strong coupling force between the two dissimilar materials can be obtained. That is, at the surface treatment step (S250), the surface of the light blocking metal plate100is treated to increase the oxygen content to form the oxygen-containing film containing oxygen. At this time, at the first resin layer coupling step (S300), the first resin layer200contains an additive compound having a functional group that reacts with the oxygen-containing film as a thermoplastic resin composition, wherein the additive compound is selected from the group consisting of a carboxyl group, a salt thereof and ester thereof, an epoxy group, a glycidyl group, an isocyanate group, a carbodiimide group, an amino group and a salt thereof, an acid anhydride group and an ester thereof.

At the surface treatment step (S250), the method of forming the oxygen-containing film on the surface of the light blocking metal plate100by increasing the oxygen content is as follows. First, the light blocking metal plate100is immersed in an aqueous zinc-ion-containing sodium solution to form a zinc-containing film, and thereafter, the zinc-containing film containing zinc element as the oxygen-containing film on the surface is formed. Second and third, the surface of the light blocking metal plate100is formed a hydrated oxide film by the hot water or warm water. Fourth, an oxide film is formed on the surface of the light blocking metal plate100by laser.

The light blocking metal plate100, which has been surface-treated so as to form the oxygen-containing film, is used as an insert, and as the thermoplastic resin composition, the first resin layer200containing the additive compound having the functional group reactive with the oxygen-containing film is injection-molded so that a strong and firm coupling force can be obtained.

Meanwhile, in order to make the surface of the light blocking metal plate100clean and smooth before performing the anodizing step (S500), a sandblasting step (S450) may be performed as shown inFIG. 12. That is, the sandblasting step (S450) is performed between the upper surface plane-cutting step (S400) and the anodizing step (S500), and the surface of the light blocking metal plate100is sandblasted to make the surface smooth. The sandblasting is effective in removing the dirt, oil, and other impurities by mixing the sand with high-pressure water and spraying the sand on the surface of the light blocking metal plate100to enhance the strength and surface quality. In particular, since the surface roughness of the light blocking metal plate100is very poor after the upper surface plane-cutting step (S400) is performed, the sandblasting step (S450) is performed before the anodizing step (S500) to smooth the surface roughness.

At the coating step (S800), as shown inFIGS. 13 and 14, the upper surface of the light blocking metal plate100is coated. Coating includes putting a thin film of paraffin, rubber resin, or a chemical material on the surface of a material. In the present invention, the surface of the light blocking metal plate100is coated with hard urethane400. In a case in which liquid urethane is mixed with a pigment having various colors, the hard urethane400is formed in a semi-transparent state. The upper surface of the light blocking metal plate100is coated with the hard urethane400, and is then dried. As a result, it is possible to improve the visibility of light emitted through the light emitting display window120. In addition, in a case in which the light blocking metal plate100is coated with the hard urethane400, it is possible to avoid leaving fingerprints on the upper surface of the light blocking metal plate100and to provide the light blocking metal plate100with an aesthetically pleasing appearance.

As described above, in the method for manufacturing a light emitting metal knob according to the present invention has the following effects.

First, the light emitting display groove110is formed on the upper surface of the light blocking metal plate at the display groove forming step (S200), and then the first resin layer200is filled in the light emitting display groove110at the first resin layer coupling step (S300) and the upper surface plane-cutting step (S400), the letters to be separated from the light blocking metal plate100is maintained in a state where the lower surface and the side surface are firmly coupled by the first resin layer200and the second resin layer300through the lower surface plane-cutting step (S600) and the second resin layer coupling step (S700), thereby considerably reducing a defect rate.

Second, the first resin layer200is coupled to the light emitting display groove110through the upper surface plane-cutting step (S400) after the display groove forming step (S200) and the first resin layer coupling step (S300), since the metal connection between the light blocking metal plate100and the letters to be separated is maintained, thereby the color of the surface can be realized even the letters to be separated from the light blocking metal plate100when the anodizing processing.

Third, an oxygen-containing film is formed on the surface of the light blocking metal plate100through the surface treatment step (S250) and an additive compound having a functional group reactive with the oxygen-containing film is contained in the first resin layer200at the first resin layer coupling step (S300), thereby a strong coupling force between the two dissimilar materials can be obtained and there is an effect of preventing the first resin layer200from being separated from the light blocking metal plate100together with the letters to be separated.

It must not be interpreted that the preferred embodiments of the present invention, which have been described above and shown in the drawings, define the technical idea of the present invention. The scope of protection of the present invention is limited by what is claimed in the claims, and various modifications and variations of the technical idea of the present invention can be made by those skilled in the art to which the present invention pertains. Therefore, such modifications and variations will fall into the scope of protection of the present invention as far as they are obvious to those skilled in the art.