KR100749118B1 - Light emitting keypad - Google Patents

Abstract

A light emitting keypad is provided to enable light emitted from a light source to be incident within a light guide film, so that the light can be emitted to the outside through the light guide film, thereby obtaining a more uniform emission surface. A key plate is equipped with plural keys. A light guide film(10) is formed under the key plate, and wherein light is incident and guided for surface light-emission. Plural top-view type light sources(30) are located under the light guide film(10). Substrates(22) are located under the light guide film(10), and are equipped with metal domes(21). Emission angles of light of entire or some of the light sources(30) are within a range of 60 to 180 degrees.

Description

Light Emitting Keypad

1 is a cross-sectional view of a conventional LED lighting keypad of the direct lighting method,

2 is a cross-sectional view of a conventional EL type light emitting keypad;

3 to 6 are cross-sectional schematic diagrams of a light-emitting keypad according to embodiments of the present invention;

7 and 8 are examples of the light guide film used in the light-emitting keypad of the present invention, a cross-sectional view of the light guide film formed with an adhesive member and a pattern,

9 to 11 is an example of a light guide film used in the light emitting keypad of the present invention, a plan view of a pattern,

12 is a cross-sectional view of a light emitting keypad according to another embodiment of the present invention;

13 is an explanatory diagram of a light emission angle of a light source of the present invention;

14 is a partial cross-sectional view of a light emitting keypad according to another embodiment of the present invention.

** Explanation of symbols for main parts of drawings **

1: keyboard 10: light guide film

12: lower reflective layer 13: pattern

14: double-sided tape 15: projection

20: circuit board 21: metal dome

22: contact terminal 30: light source

40: bonding member 41: reflective layer

50: reflective layer A: light emission angle

The present invention relates to a light emitting keypad.

In general, the light-emitting keypad is applied to a communication device such as a mobile phone is used as a switch device for generating a signal or performing various additional functions, and has a function of identifying keys such as numbers or letters at night or in a dark place, Recently, as the thinning of portable terminals is accelerated, ultra-thin light emitting keypads have been developed and applied.

1 is a cross-sectional view of an LED keypad of a conventional direct lighting method, and includes a printed circuit board 100, a dome 102, an LED 103 for direct illumination, and a keypad 104. The printed circuit board 100 includes a predetermined contact terminal 101, and a plurality of the dome and the direct lighting LED are installed on the front surface of the printed circuit board. In addition, a number or letter is printed on the upper surface of the dome and the LED for direct lighting, and a keypad provided with the projection 105 is provided on the lower surface.

Such a direct-lighting LED keypad is a direct light LED installed on the front of the printed circuit board is illuminated to illuminate the keypad. That is, when the keypad is pressed by the user, the dome and the contact terminals of the printed circuit board are connected by the projections of the keypad to generate a predetermined electric signal, and the LED emits light by the generated electric signal to form the keypad as a point light source. To directly reflect.

However, the above-described direct-illumination type LED keypad cannot be manufactured in a thin form due to the characteristics of the LED, so that the keypad is made relatively thick. In addition, the power consumption according to the LED light emission can be shortened the use time of the battery. In addition, the uniformity of light emission is uneven depending on the arrangement position of the LED, which leads to design difficulties.

2 is a cross-sectional view of a conventional EL type light-emitting keypad for solving the above problems, and includes a key top 110, an EL metal dome sheet 120, and a printed circuit board 130, and the EL metal dome sheet 120. ) Is composed of an EL sheet 121, a metal dome 123, and a base tape 122 to realize ultra-thin film and low power consumption.

Looking at the function of the EL-type metal dome keypad, when the key top 110 is pressed by the user, the fixed contact of the metal dome 123 and the printed circuit board 130 by the protrusion 111 located on the back of the key top 110. The terminal 131 is contacted and switched to operate.

However, in the conventional EL type light emitting keypad, the EL sheet 121 is continuously pressed and impacted by the projections 111, so that there is a high risk of damage or breakage of the EL sheet, thus causing a large problem in the reliability of the EL and the keypad. There is a problem that causes a drop in the click feeling. In addition, due to the characteristics of the EL sheet has a shorter life than the LED, causing noise in the LCD module, there is a problem that the reliability is poor. In addition, there is a problem that the manufacturing cost increases than when manufacturing the LED keypad.

On the other hand, the conventional Top View method has a disadvantage in terms of manufacturing process and cost due to the large number of light sources used, and there is a problem in that light leakage is immediately emitted to the outside and light leakage occurs. Is required.

In order to solve the above problems, it may be considered to provide an LED light source by an indirect lighting method and to install an optical fiber having excellent light transmission characteristics in order to uniformly supply light to the keypad. There is a problem that is difficult to apply.

Accordingly, the present invention is to solve the above problems, the light emitted from the light source positioned in the top view method through the light guide film is incident to the light guide film to emit more uniform light emission through the light guide film to the outside It is an object of the present invention to provide a light emitting keypad that can obtain a surface, and can obtain the same or better effect even if the number of light sources used in the past is small.

On the other hand, an object of the present invention is to provide a light-emitting keypad which can prevent the light leakage phenomenon by introducing a coupling member, such as a reflective layer as needed to block the emitted light to the outside.

The present invention for achieving the above object,

A keypad provided with a plurality of keys; A light guide film formed under the keypad and light is incident and guided to emit light; A plurality of light sources having a top-view positioned under the light guide film; And a substrate disposed under the light guide film and provided with a dome switch.

In addition, all or part of the light source provides a light emitting keypad, characterized in that the emission angle of the light is in the range of 60 ° to 180 °.

In addition, the light guide film provides a light emitting keypad characterized in that a through hole is formed in a region corresponding to the light source so that light of the light source is incident into the light guide film.

In addition, the light emitting keypad is characterized in that a bonding member selected from at least one of a reflective layer, a translucent layer, and a transparent layer is formed on the through hole of the light guide film.

In addition, the lower portion of the light guide film provides a light emitting keypad, characterized in that the projection is formed to correspond to the dome switch to press the dome switch.

In addition, the lower portion of the light guide film provides a light emitting keypad, characterized in that the reflective layer which is in contact with or spaced apart from the light guide film is formed.

In addition, the reflective layer is a reflective sheet (Sheet), using a double-sided tape to provide a light emitting keypad, characterized in that attached to one side, both sides or the entire surface of the rear surface of the light guide film.

In addition, the reflective layer includes silver (Ag), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), barium sulfate (BaSO ₄ ), zinc emulsion (ZnS), lead white, and antimony oxide (Sb ₂ O _3). Provided is a light-emitting keypad comprising one or more from the group consisting of.

In addition, at least one surface of the front and rear of the light guide film is formed in a pattern in the form of increasing the density as the distance from the light source so that the light is uniformly supplied to the keypad, or the light is concentrated to the predetermined area of the keypad Provided is a light emitting keypad characterized in that the pattern is formed concentrated on a specific region of the light guide film.

In addition, the pattern provides a light emitting keypad, characterized in that formed by any one of the processing method of hot stamping, injection molding, micro blast, laser.

In addition, the pattern provides a light emitting keypad, characterized in that formed by silk-printing the ink containing the light scattering agent on the light guide film.

In addition, the density of the pattern provides a light emitting keypad, characterized in that the adjustment by at least one method of adjusting the distance of the pattern and the size of the pattern.

In addition, the keypad provides a light emitting keypad, characterized in that the key is a flat-panel keypad displayed in color.

In addition, the light emitting keypad is characterized in that the reflective layer is located on all or a part of the upper portion of the substrate.

The present invention also includes a substrate having a metal dome; A plurality of top-view light sources positioned on the substrate; And a light guide film positioned on an upper portion of the light source and receiving light and being guided to surface light emission.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

3 is a cross-sectional view of a light emitting keypad according to an embodiment of the present invention. As shown in the drawing, a key plate 1 having a plurality of keys, a light guide film 10 formed under the key board 1, and light is incident and guided to emit light, and a top view positioned below the light guide film. A plurality of light sources 30 in a top view, and a substrate 22 positioned below the light guide film and provided with a metal dome 21 are provided. Key shapes and keypads are well known in the art and are not shown in detail. The lower protrusion 15 is formed at the bottom of the keypad 1 to improve accurate key manipulation and click feeling. In addition to the configurations listed above, other configurations may be added as needed, and all are included in the present invention.

The light emitting keypad according to the present invention receives light emitted from the light source 30 positioned in the top view method through the light guide film 10 into the light guide film, so that the light of the light source does not directly reach the light source through the light guide film. By guiding light and emitting it to the outside, it is possible to obtain a uniform light emitting surface than when the light guide film is not used, and the same or better effect can be obtained even when the number of light sources used in the past is small.

The material of the light guide film 10 is a material that can provide accurate switching and excellent click feeling with excellent light guiding property, easy molding, and flexibility and elasticity. As a result of repeated experiments with materials that can satisfy these characteristics, polycarbonate (PC) and polyethylene terephthalate (PET) were found to be the best. In particular, in the case of polycarbonate (PC) or polyethylene terephthalate (PET), the flexibility is excellent, and when a specific key on the keypad is pressed, only a specific area is bent, and only a specific key is switched. When is released, it can be returned to its original state.

The substrate 20 is not particularly limited, but may be the printed circuit board (PCB) and may include a dome switch including a metal dome 21 and a contact terminal 22. In addition, the substrate may be a dome substrate in which the metal dome 21 is integrally formed. Therefore, when the key plate of the light emitting keypad is pressed by the user, the pressing area of the light guide film 10 is elastically deformed by pressing to press the corresponding metal dome 21 of the substrate 20, and thus the metal dome 21. The contact terminal 22 is in contact with and switched.

The light source 30 is not particularly limited, LED is most preferred. Color can be easily implemented and manufacturing cost is low. The light source is positioned under the light guide film to emit light to the light guide film, is incident to the light guide film, the light is diffused by the light guide film is converted to the surface light is emitted to the outside. A plurality of light sources are provided.

Protrusions 15 may be formed on the rear surface of the keypad 1. The shape of the protrusions is not limited, and any protrusions formed to press the dome switch are included in the present invention. By providing the projections 15, the click feeling is improved and the dome switch can be switched with less force.

The material of the protrusion 15 is not limited, but silicone or polymer resin may be selected, and the same material as the light guide film may be selected. As a method of forming the protrusions 15, the protrusions may be directly formed on the light guide film, or the back layer on which the protrusions are formed may be attached to the rear surface of the keypad. Liquid silicone or film silicone, polymeric resin, etc. are formed by compression molding at 100 to 150 degrees using a molding mold formed corresponding to the back layer and / or protrusion 15, or by UV lithography or IR by photolithography. It is formed by screen printing the curing ink.

The keypad 1 may be a keypad in which a key is convex or concave. In addition, the key may be a flat plate formed of a flat plate. That is, the key may be expressed by different colors of the key and the non-key area on the keypad. That is, a colored layer may be provided and colored as shown in an area excluding a key on the upper portion of the light guide substrate. It is also possible to color the key in a different color. As a result, the colors of the key and the non-key region are expressed differently, and the keys are displayed in a flat plane. In addition, the method of expressing a key may vary, and all of them are included in the present invention. Keys, such as letters and numbers, may be formed transparently or semi-transparently so that light is emitted in the shape of the key.

4 is a cross-sectional view of a light emitting keypad according to another embodiment of the present invention. As shown, a reflective layer 41 capable of reflecting light in the upper region of the light guide film 10 corresponding to the position of the light source 30 may be formed. Firstly, the light emitting surface may be more uniform and have higher brightness by reflecting through the reflective layer 41, incident light into the light guide film, and emitting to the outside through the light guide film. In addition, it is possible to block the emitted light directly to the outside through the upper reflective layer to prevent the light leakage effect.

The reflective layer 41 may be selected without limitation as long as it is a material capable of reflecting light, and a white pigment or the like may be used and may be used alone or in a paste type. Preferably one of silver (Ag), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), barium sulfate (BaSO ₄ ), zinc emulsion (ZnS), lead white and antimony oxide (Sb ₂ O ₃ ) It is good to be selected and used above.

 The upper reflective layer may be formed by forming a reflective layer on the rear surface of the light guide film by a vapor deposition method, or may be coated, printed, or the like. The deposition method, coating method, and printing method are well known, and thus detailed description thereof will be omitted.

More preferably, the reflective layer 41 manufactured in the form of a sheet may be attached to a predetermined region of the light guide film 10 using an adhesive such as a tape for the convenience of the process.

5 and 6 are cross-sectional views of a light emitting keypad according to another embodiment of the present invention. As shown, the light guide film 10 is characterized in that the through-hole 11 is formed in a region corresponding to the light source so that the light of the light source 30 is incident into the light guide film. In addition, at least one bonding member 40 selected from a reflective layer, a translucent layer, and a transparent layer may be further formed on the through hole of the light guide film. The light source may be close to the through hole, or partially inserted into the through hole.

In particular, the light source is not limited, but the emission angle A of the light shown in FIG. 13 is preferably greater than 60 °, and preferably within the range of 180 °. In particular, when a part of the light source is inserted into the through hole, the emission angle must be large to allow more light to enter the light guide film.

The bonding member 40 may prevent light leakage from occurring by directly emitting light from a light source to the outside. In the case of the transparent tape, the light source may be particularly useful in the case where the position of the light source is a region where no light is emitted from the keypad. In addition, the bonding member may serve to prevent the damage that may occur in the through hole during the key operation and to support the light guide film is slim because the light guide film is slim.

The bonding member may be configured with the above-described reflective layer to increase the brightness of the light guide film. It may also be a translucent material. The bonding member may be in the form of a tape fixed with an adhesive or an adhesive (adhesive) layer formed.

7 to 8 are diagrams showing an example of the light guide film 10 used in the light emitting keypad of the present invention. The lower reflective layer 12 may be formed on the rear surface of the light guide film 10 to improve the luminance of the light emitting surface of the keypad. This is to prevent light from being emitted and extinguished through the rear surface of the light guide film. In particular, when the lower reflective layer is formed on the rear surface of the light guide film and the pattern to be described later is formed on the rear surface of the light guide film, light is scattered by the rear pattern, and light is emitted to the front surface of the light guide film by the reflective layer, thereby providing more uniform light emission. You can get the noodles. The lower reflective layer is not preferably formed in the region where the light source is located.

The material and the method of forming the lower reflective layer 12 may be applied and used without being limited to the material and the method of forming the reflective layer described above.

 The method of forming the lower reflective layer may be a reflective layer formed on the rear surface of the light guide film by a deposition method, a coating method, a printing method, etc. may be used, and preferably, as shown in FIG. For the convenience of the process, it is preferable to attach the prepared lower reflective layer 12 to the rear surface of the light guide film 10 using the double-sided tape 14. That is, the reflective layer is made of a sheet containing a reflective material, it is preferable to be attached to one side end, both side ends or the entire surface of the rear surface of the light guide film using an adhesive or double-sided tape.

The lower reflective layer 12 may be in close contact with the light guide film, and may be spaced apart from the light guide film at predetermined intervals. As one method for spaced apart by the predetermined interval, it can be realized by using a double-sided tape having a predetermined thickness to one side or both ends of the light guide film. That is, when only one side or both ends are bonded to the light guide film and the reflective layer, spaces at predetermined intervals are generated at other portions corresponding to the thickness of the double-sided tape.

If necessary, when the length of the reflective layer is longer than the length of the light guide film and the ends are bonded, the reflective layer may be further separated by the length of the extra reflective layer. Particularly, in the case of the light emitting keypad, since the substrate having the curved metal dome is positioned below the light guide film, it is also preferable to form the reflective layer sufficiently long so that the reflective layer can be placed in contact with the substrate having the metal dome. .

At least one of the front and rear (not shown) of the light guide film 10 is characterized in that the pattern 13 is formed so that the light is uniformly supplied to the keypad. Although only the concave pattern is formed on the light guide film, the present invention is not limited thereto, and the convex pattern is also included in the present invention. The light is refracted and scattered by the pattern so that the light is emitted to the keypad and a uniform light emitting surface can be obtained.

9 to 11 are plan views showing another example of the pattern 13 of the light guide film 10 used in the light emitting keypad of the present invention. As shown, it is desirable to form the pattern in a form in which the density increases as it moves away from the light source 30 to provide a uniform light emitting surface. That is, since the supply amount of the light source decreases as it moves away from the light source, the density of the pattern is increased to allow more light to be scattered, thereby obtaining a more uniform light emitting surface. As shown, the density of the pattern may be adjusted by adjusting the distance of the pattern, that is, the distance between the patterns (FIG. 9), or the density of the pattern may be adjusted by adjusting the size of the pattern (FIG. 10). On the other hand, in order to provide more light emission to a specific area (for example, a character area of the keypad) rather than a uniform light emitting surface, a concentrated light emitting surface may be provided by dense a pattern in a specific area (FIG. 11).

The shape of the pattern 13 is not particularly limited and is included in the present invention as long as the surface of the light guide film is processed or printed. Forming method of the pattern is not limited, but is preferably formed by any one of hot stamping method, injection molding, micro blast, laser processing method of heating the patterned mold and pressing the light guide film to transfer the pattern to the light guide film. It is good to be. In addition, the ink containing the light scattering agent may be silk printed on the light guide film to form a pattern.

12 is a cross-sectional view of a light emitting keypad according to another embodiment of the present invention. As shown, the projection 15 is not located on the rear surface of the keypad 1 to correspond to the metal dome in order to press the metal dome 21 on the rear surface of the light guide film 10. Can be formed. The shape of the projections, the manufacturing method and the like are as described above. Since the protrusions are positioned below the light guide film, the light guide film may be pressed by the protrusions, thereby eliminating the possibility of deformation.

14 is a partial cross-sectional view of a light emitting keypad according to another embodiment of the present invention. As shown, the reflective layer 50 is positioned on all or a part of the upper portion of the substrate 20. The reflective layer also includes the aforementioned reflective sheet. Since the reflective layer is positioned on the substrate, the luminance of the light emitting keypad may be increased by reducing light loss that may occur in the substrate. On the other hand, the metal dome may be formed individually, but it is preferable to use an integrated dome substrate, which may be equally applied to the above-described embodiment.

The invention also provides a substructure of the light emitting keypad shown as an example in FIGS. 3 to 6, 12, and 14. That is, the substrate 20 having the metal dome 21, the plurality of top-view light sources 30 positioned on the substrate, and the light located on the light source is incident and guided. It provides a lower structure of the light emitting keypad having a light guide film 10 for emitting light. Each configuration can apply all the features of the above-described configuration, and since the above has been described sufficiently, the description is omitted.

The above embodiments are intended to describe the present invention in detail, and are not intended to limit the present invention, and thus modifications, modifications, omissions, etc. that can be applied within the scope of the technical idea of the present invention are defined by the claims. It is included in the scope of the invention.

Due to the above characteristic configuration, the following effects are provided. That is, the light emitting keypad according to the present invention receives light emitted from the light source positioned in the top view method through the light guiding film into the light guiding film and emits the light to the outside through the light guiding film to obtain a more uniform light emitting surface. The same or better effect can be obtained even if the number of light sources used in the related art is small, and if necessary, a coupling member such as a reflective layer can be introduced to increase the luminance of light at the key position and the emitted light is immediately emitted to the outside. It can block the light leakage phenomenon.

Claims (16)

delete A keypad provided with a plurality of keys; A light guide film formed under the keypad and light is incident and guided to emit light; A plurality of light sources having a top-view positioned under the light guide film; And A light emitting keypad comprising: a substrate positioned below the light guide film and provided with a metal dome. All or part of the light source is a light emitting keypad, characterized in that the emission angle of light in the range of 60 ° to 180 °. A keypad provided with a plurality of keys; A light guide film formed under the keypad and light is incident and guided to emit light; A plurality of light sources having a top-view positioned under the light guide film; And A light emitting keypad comprising: a substrate positioned below the light guide film and provided with a metal dome. The light guide film is a light emitting keypad, characterized in that the through-hole is formed in the area corresponding to the light source so that the light of the light source is incident to the light guide film. The light emitting keypad of claim 3, wherein a bonding member selected from at least one of a reflective layer, a translucent layer, and a transparent layer is formed on the through hole of the light guide film. The light emitting keypad according to any one of claims 2 to 4, wherein a protrusion is formed at a lower portion of the light guide film to correspond to the metal dome to press the metal dome. The light emitting keypad according to any one of claims 2 to 4, wherein a lower reflective layer is formed below the light guide film to be in contact with or spaced apart from the light guide film. The light emitting keypad according to claim 6, wherein the reflective layer is a reflective sheet and is attached to one end, both sides, or the entire surface of the rear surface of the light guide film by using a double-sided tape. The method of claim 6, wherein the reflective layer is silver (Ag), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), barium sulfate (BaSO ₄ ), zinc emulsion (ZnS), lead white, and antimony oxide ( Sb ₂ O ₃ ) A light-emitting keypad comprising one or more from the group consisting of. The pattern of any one of claims 2 to 4, wherein at least one of the front and rear surfaces of the light guide film is formed in a form in which the density increases as the light moves away from the light source so that the light is uniformly supplied to the keypad. The light emitting keypad characterized in that the pattern is concentrated to a specific area of the light guide film so that light is concentrated to a predetermined area of the keypad. The light emitting keypad according to claim 9, wherein the pattern is formed by any one of hot stamping, injection molding, micro blasting, and laser processing methods. The light emitting keypad of claim 9, wherein the pattern is formed by silk printing an ink containing a light scattering agent on a light guide film. The light emitting keypad of claim 9, wherein the density of the pattern is adjusted by at least one of distance adjustment and pattern size adjustment of the pattern. A keypad provided with a plurality of keys; A light guide film formed under the keypad and light is incident and guided to emit light; A plurality of light sources having a top-view positioned under the light guide film; And A light emitting keypad comprising: a substrate positioned below the light guide film and provided with a metal dome. The keypad is a light emitting keypad, characterized in that the key is a flat-panel keypad, the color-coded display. The light emitting keypad according to any one of claims 2 to 4 and 13, wherein a reflective layer is positioned on all or a part of the upper portion of the substrate. A substrate having a metal dome; A plurality of top-view light sources positioned on the substrate; And As a lower structure of the light emitting keypad having a light guide film positioned on top of the light source and the light is incident and guided surface emitting light; All or part of the light source is a light emitting keypad, characterized in that the emission angle of light in the range of 60 ° to 180 °. The light emitting keypad of claim 15, wherein the light guide film has a through hole formed in a region corresponding to the light source so that light from the light source is incident into the light guide film.

Images