KR20080076067A - Light guide keyboard and light emitting keypad having same - Google Patents

Abstract

The present invention provides a light guide panel and a light emitting keypad including a light guide substrate capable of surface emitting incident light, and a plurality of keys formed on the light guide substrate and capable of emitting light. Compared to the light emitting keypad, it is possible to significantly reduce the size and simplify the manufacturing process and assembly.

Description

Light Guide Key-Plate And Light Emitting Keypad Comprising The Same}

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 light emitting keypad having a light guide keypad according to an embodiment of the present invention;

3 is a schematic view of a light source used in a light emitting keypad according to an embodiment of the present invention;

4A to 4C illustrate a plan view, a partial cross-sectional view, and a pattern of a light guide keyboard according to an embodiment of the present invention;

5 to 7 are cross-sectional views of a light guide keypad and a light emitting keypad according to another embodiment of the present invention;

8 to 9 are cross-sectional views of a substrate and the like of a light emitting keypad according to another embodiment of the present invention.

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

10: Light guide keyboard 11: Light guide substrate

12: key 13: colored layer

14: hard coating layer 15: pattern

16: reflective layer 17: hole

18: Slit

20: light source 30: substrate

31: contact terminal 32: metal dome

40: back layer 41: lower protrusion

42: upper projection

50: reflective layer

The present invention relates to a light guide keypad and a light emitting keypad having the same.

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. A number or letter is printed on the upper surface of the dome and the direct lighting LED, 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, in the case of the conventional top view method, the number of the light sources is large, which is disadvantageous in terms of manufacturing process and cost, and the light emitted from the light source is immediately emitted to the outside, causing light leakage. Required.

In order to solve the above problem, it is conceivable to consider a light emitting keypad which inserts the light guide plate into the keypad and indirectly lights, ie, emits light by surface emitting light using the light guide plate. However, in this case, since a separate light guide plate must be inserted into the keypad, there is a limitation in slimming the keypad, and there is a problem in that a separate light guide plate must be manufactured and assembled.

The present invention is to solve the above problems, without providing a separate light guide plate, by using a light guide substrate having a light guiding function of the keypad of the keypad by providing a light guide keyboard further realize a slimmer keypad, and a separate light guide plate It is an object of the present invention to provide a light guide keypad and a light emitting keypad having the same, which can solve manufacturing costs and costs.

The present invention for achieving the above object,

A light guide substrate capable of surface emitting incident light; And a plurality of keys formed on the light guide substrate and capable of emitting light.

In addition, by forming a colored layer on the upper portion of the light guide substrate, except for the key region, provides a light guide keyboard characterized in that the key is divided into colors to represent a flat plate.

In addition, the light guide substrate provides a light guide keyboard, characterized in that a slit is formed to separate all or part of the key.

In addition, the slit is provided with a light guide keyboard, characterized in that filled with a transparent polymer material or silicon having a higher ductility than the light guide substrate.

In addition, the light guide substrate provides a light guide keyboard having a thickness in the range of 0.1 to 0.6 mm.

In addition, the light guide keyboard is characterized in that the reflective layer is formed in all or part of the region between the colored layer and the light guide substrate.

In addition, at least one of the upper surface and the lower surface of the light guide substrate provides a light guide keyboard, characterized in that the pattern is formed to correspond to the position of all or part of the key.

In addition, the light guide substrate provides a light guide keyboard, characterized in that a hole is formed in a region corresponding to the light source so that light arriving from a light source positioned below is incident on the light guide substrate.

In addition, the light guide keyboard is characterized in that the hard coating layer is further formed on the top.

The invention also, the above-described light guide keyboard; A plurality of light sources having a top-view positioned under the light guide keyboard; And it provides a light emitting keypad comprising a substrate having a dome switch is located below the light guide key board.

In addition, the lower light guide, there is provided a light emitting keypad, characterized in that the lower projection for pressing the dome switch is formed.

The present invention also provides a light emitting keypad, wherein an upper protrusion is formed on an upper portion of the dome switch.

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.

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 °.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The following description is a description of some embodiments of the present invention, and the present invention is not limited by the following detailed description, and the scope of the present invention is determined by the matters described in the claims. For example, although the portion described as 'key' in the claims is described in the form of a plane in the following example, it is only some embodiments, and is known as 'key', for example, protrusion in the art to which the present invention belongs. All keys of the form also correspond to the 'key' of the present invention.

2 is a schematic cross-sectional view of a light guide keypad and a light emitting keypad according to an embodiment of the present invention. As illustrated, the light guide substrate 10 includes a light guide substrate 11 capable of surface emitting incident light, and a plurality of keys 12 formed on the light guide substrate 11 and capable of emitting light. ), A plurality of top-view light sources 20 positioned under the light guide keyboard 10, and dome switches 31 and 32 positioned under the light guide keyboard 10. It is characterized in that the light emitting keypad comprising a substrate (30). Other configurations may be further added in the above configuration as needed. As an example, the lower protrusion 41 may be further included.

The light guide keyboard 10 will be described later in detail.

The light source 20 is not particularly limited as long as it is a top view light source, but LED is most preferred. Color can be easily implemented and manufacturing cost is low. Although the light source is not limited, the light source is positioned at one end of the light guide keyboard and becomes a light source, and the emitted light is changed into surface light by the light guide keyboard.

3 is an example of a preferred light source, and it is preferable that the emission angle A of the light is in the range of 60 ° to 180 °. If it is less than the above range, it is difficult to obtain the required uniformity of light emission, and above the above range, light loss may occur. In particular, as described later, when a hole is formed in the light guide substrate and a part of the light source is inserted, the emission angle can obtain more efficient light emission within the above range.

The substrate 30 is not particularly limited, but may be the printed circuit board (PCB) and includes a dome switch including a metal dome 32 and a contact terminal 31. Therefore, when the key of the keypad is pressed by the user, the pressed area is selectively elastically deformed to press the corresponding metal dome 32 of the printed circuit board 30, whereby the metal dome 32 contacts the contact terminal 31. Is switched on. The metal dome may be formed individually as shown, or may be an integrally formed dome substrate.

In addition, a lower protrusion 41 for pressing the dome switch may be further formed under the light guide keyboard 10. The lower protrusion 41 may be provided by adhering the back layer provided with the protrusion to the bottom of the keypad.

The rear layer and the lower protrusion may be excellent in elastic restoring force, and the material may be silicone or polymer resin.

The lower protrusions 41 may be formed in plurality to correspond to the positions of all or a part of the keys of the light guide keyboard. When the key is pressed by the user, the lower protrusions 41 are pressed to make electrical connections in the switching unit such as the dome switch. Get up.

Next, the light guide keyboard 10 will be described in detail. The light guide keyboard includes a light guide substrate 11 capable of surface emitting incident light, and a plurality of keys 12 formed on the light guide substrate 11 and capable of emitting light.

The light guide substrate 11 is not limited as long as it is a transparent material having a light guide function, and all are included in the present invention. The material of the light guide substrate 11 is preferably a material having excellent light guiding property, slim and excellent in physical properties, but is not limited to polycarbonate (PC) and polyethylene terephthalate (PET). The thickness of the light guide substrate is preferably a slim range while giving the physical properties required as the keypad, but is not limited to 0.1 to 0.6 mm, more preferably 0.2 to 0.4 mm. The light guide substrate may be expressed in the form of a kind of slim film. The light emitted from the light source 20 is incident to the light guide 20 at the rear surface of the light guide substrate 11 and is converted to surface light emission to emit light even at a part far from the light source.

The key 12 may be formed of a flat plate as shown. That is, the key 12 may be formed on the light guide substrate 11 to form a colored layer 13 except for the key 12 region, thereby expressing the key as a flat plate. Of course, it is also possible to distinguish the keys by coloring the area of the key 12 with other colors or making them translucent. 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 be various, and expressing such that it protrudes is all 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.

The colored layer 13 may be colored by printing or vapor deposition to give a feeling of stainless steel or magnesium, and after forming the colored layer, the colored layer 13 may be formed by etching such as laser processing. By etching, the colored region and the key region can be distinguished. In the present invention, since the keypad plays a role of light guiding, the colored layer must be positioned above the keypad to effectively express the keys. Further, in the colored layer, light is not emitted so that the ratio of light emission of the key is increased.

In addition, when the material for which the light is relatively reflected by the colored layer 13 itself is used, light loss can be reduced, and thus the luminance of light emitted from the key can be increased. That is, the material of the reflective layer to be described later may be used or part thereof.

The hard coating layer 14 may be formed on the light guide substrate. Problems such as scratching can be solved through the hard coating layer, and the colored layer can be protected. The slit portion may be formed so that the slit can function efficiently by excluding the hard coating layer. The material of the hard coating layer is not limited, but it is preferable to use a cured resin having excellent surface hardness by curing with ultraviolet rays and / or heat. As the thermosetting hard coating agent such as silicone type or melamine type or the ultraviolet curing type hard coating agent, radical polymerizable hard coating agents such as unsaturated polyester resins, acrylics, etc., cationically polymerizable hard coating agents such as epoxy or vinyl ether can be used. have. In addition, it is possible to use an ultraviolet curable resin in which a thermosetting component is slightly added to partially heat curing. Since the hard coating agent is commercially available, detailed description is omitted.

4A to 4C are plan views, partial cross-sectional views, and perspective views of a light guide keyboard 10 according to an embodiment of the present invention.

As illustrated, the light guide substrate 11 may include a slit 18 for separating all or part of the key. When the slit 18 is formed in the light guide substrate 11, when pressing a specific key 12, it is possible to prevent other keys from being pressed together, thereby preventing malfunction and increasing a feeling of click.

In this case, when the slit 18 is formed, there may occur a problem that light loss occurs in the slit portion. In order to compensate for this, the present invention may fill the slit 18 with a transparent material having a higher ductility than the light guiding substrate so that the light guiding may be effectively performed. By using a material that is softer than the light guide substrate, the keys separated by the slits can be moved independently, and at the same time, the light guide efficiency can be increased.

Examples of the transparent material having better ductility than the light guide substrate 11 may include rubber or polyurethane.

When filling the slit 18 with the material, it may be filled only with the slit, and although not shown, the material is not limited but formed as a thin film of 10 to 40 μm on the top or / and bottom surface of the light guide substrate 11. At the same time, the slit 18 may be integrally filled with the material. In this case, the material may be tightly bound than when the material is filled only in the slit.

The pattern 15 may be formed on at least one of the upper surface (not shown, the pattern is formed on the upper surface) and the lower surface of the light guide substrate 11 to correspond to the position of all or part of the key. The light is refracted and scattered by the pattern, so that light emission is concentrated more in the region where the pattern exists than in the case where there is no pattern. It is preferable that the pattern is concentrated and formed in a specific region of the light guide substrate 11 so that light is concentrated in the region of the key (shown in FIG. 4C). In addition, as the distance from the light source increases, the area occupied by the pattern is increased so that more light is scattered, thereby obtaining a more uniform light emitting surface. In the case of the keypad, it is important to emit light more intensively in areas of keys such as numbers and letters, so it is better to position the pattern correspondingly. The shape of the pattern is not particularly limited and may be convex or concave.

The method of forming the pattern 15 is not particularly limited, and the pattern may be formed by a possible method such as hot press processing, printing method, ultrasonic processing, laser processing, molding injection, or the like. It is preferable to use the method of hot press preferably. Since the light guide substrate of the present invention can be regarded as a slim film, it is better than forming a pattern by injection molding. However, the method by injection molding is not excluded. In addition, even in the case of the hot press method, if the mold to be heated to a high temperature is used, the light guide substrate may be thermally deformed, such as loss. Therefore, it is preferable to use a mold heated to a temperature within such a range that such a loss does not occur. Although not limited, it is preferable to be formed by a hot press method using a mold heated in the range of 70 to 150 ℃.

The pattern 15 may be formed by silk printing an ink containing a light scattering agent on a light guide substrate.

FIG. 5 is a cross-sectional view of a light guide keypad and a light emitting keypad according to another embodiment of the present invention, in which a light guide keyboard 10 further including a reflective layer 16 is formed on all or part of the colored layer 13 and the light guide substrate 11. It is characterized by). If the colored layer 13 is not a light emitting region, it is necessary to prevent the light from being absorbed in the colored layer to cause a loss. To this end, the reflective layer 16 is first formed on the light guide substrate 11 and the colored layer 13 is formed to prevent light from being absorbed from the colored layer through the reflective layer, thereby increasing the light guide efficiency in the light guide substrate 11. You can. The reflective layer 16 may be formed in a non-light emitting area, for example, an area except for the key 12. In addition, it is possible to obtain a more uniform and higher luminance emitting surface by first reflecting through the reflective layer 16, incident light into the light guide substrate, and emitting the light to the outside through the light guide substrate. 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 16 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.

In addition, the reflective layer may be or include a translucent material that partially reflects light.

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

More preferably, the reflective layer 16 manufactured in the form of a sheet is attached to a predetermined region of the light guide substrate 11 using an adhesive such as a tape for the convenience of the process.

6 is a cross-sectional view of a light guide keypad and a light emitting keypad according to another embodiment of the present invention. As illustrated, the light guide substrate 11 may include the light source such that light of the light source 20 is incident into the light guide substrate. The hole 11 is formed in the corresponding area. The light source 20 may be close to the hole 11 or partially inserted into the hole.

The hole may also be formed to penetrate the light guide substrate, and may include a hole formed in a groove not penetrating the light guide substrate. A plurality of holes may be formed.

In particular, the light source is not limited, but as described above, the emission angle A 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 hole, the emission angle must be large to allow more light to enter the light guide substrate.

7 is a cross-sectional view of a light guide keypad and a light emitting keypad according to another embodiment of the present invention. The efficiency can be improved.

8 is a partial cross-sectional view of a light emitting keypad according to another embodiment of the present invention, as shown in the figure, further comprising a back layer having an upper protrusion 42 formed on top of the dome switches 31 and 32. Can be. That is, instead of the lower protrusion 41 described above, the upper protrusion 42 may be formed. The description of the back layer and the projections will be as described above and the description will be omitted.

9 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 may be located on all or a portion of the upper portion of the substrate 30. 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. That is, since the reflective layer 50 reflects the light reflected from the light guide keyboard 10 to be emitted to the outside through the light guide keyboard 10, the brightness of the light guide keyboard 10 may be improved. On the other hand, the dome switch 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 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 present invention provides a light guide key board and a light emitting keypad in which a key plate acts as a light guide without a separate light guide plate, thereby making it significantly slimmer than a light emitting keypad using a separate light guide plate and simplifying the manufacturing process and assembly.

Claims (14)

A light guide substrate capable of surface emitting incident light; And And a plurality of keys formed on the light guide substrate and capable of emitting light. The light guide keyboard according to claim 1, wherein a color layer is formed on the light guide substrate, except for the key region, and the keys are divided into colors to represent a flat plate. The light guide keyboard according to claim 1, wherein the light guide substrate is formed with slits separating all or part of the keys. The light guide keyboard according to claim 3, wherein the slit is filled with a transparent polymer material or silicon having a higher ductility than the light guide substrate. The light guide keyboard according to claim 1, wherein the light guide substrate has a thickness in the range of 0.1 to 0.6 mm. The light guide keyboard according to claim 1, wherein a reflective layer is formed on all or part of the region between the colored layer and the light guide substrate. The light guide keyboard according to claim 1, wherein at least one of an upper surface and a lower surface of the light guide substrate has a pattern corresponding to a position of all or a part of the key. The light guide keyboard of claim 1, wherein a hole is formed in a region corresponding to the light source so that light received from a light source positioned below the light guide substrate is incident on the light guide substrate. The light guide keyboard according to claim 1, wherein a hard coating layer is further formed on the top. The light guide keyboard of any one of claims 1 to 9; A plurality of light sources having a top-view positioned under the light guide keyboard; And A light emitting keypad comprising a substrate having a dome switch located below the light guide key board. The light emitting keypad of claim 10, wherein a lower protrusion is formed under the light guide keyboard to press the dome switch. The light emitting keypad according to claim 10, wherein an upper protrusion is formed on an upper portion of the dome switch. The light emitting keypad of claim 10, wherein a reflective layer is positioned on all or a portion of the substrate. The light emitting keypad of claim 10, wherein all or part of the light source has an emission angle of light within a range of 60 ° to 180 °.

Images