KR100765883B1 - Light emitting keypad comprising lightguide film - Google Patents

Abstract

A light emitting keypad having a waveguide film is provided to emit uniformly surface light and improve the light emitting brightness of a specific region by forming a dot pattern on the waveguide film. A light emitting keypad comprises the followings: a keyboard(10) which forms plural keys; a backing layer(20) which is positioned at the lower part of the keyboard and has plural upper projections(21) in correspondence with the whole or the part of the keys; and a waveguide film(30) which is formed in the lower part of the backing layer and is emitted by guiding light incident from a light source(50). A light emitting pattern(22) is formed in the predetermined region of the backing layer and in the upper side of the upper projections.

Description

Light Emitting Keypad Comprising LightGuide Film with Waveguide Film

1 is a perspective view of a general wireless terminal,

2 is a cross-sectional view of a light emitting keypad with a conventional EL device,

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

4 is a plan view of a mask used to form a pattern in the waveguide film according to an embodiment of the present invention,

5 is a plan view of a waveguide film according to an embodiment of the present invention,

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

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

** Description of the main symbols in the drawings **

10: keyboard

20: back layer

21: upper projection

22: outgoing pattern

30: waveguide film

31: dot pattern

32: bending pattern

40: printed circuit board

41: metal dome

42: contact terminal

50: light source

60: mesh

61: metal mask

62: hall

The present invention relates to a light emitting keypad and a waveguide film for the light emitting keypad.

1 is a perspective view showing a general wireless terminal.

As shown in FIG. 1, a wireless terminal such as a cellular phone has a liquid crystal display 120 displaying various information required for operation such as a transmission and reception state, and a plurality of keys of a keypad for performing signal generation and various functions. It is composed of a key panel 110 having a hole in which the buttons 130 are fitted.

The keypad has a plurality of key buttons 130 having a printed surface on which numbers or letters are printed, and the key buttons 130 have a structure protruding outside the key panel 110 of the mobile phone. The user checks the number or letter displayed on the printing surface and presses the desired key button 130 to use the mobile phone. A light source made of a light emitting element is provided on the outside of the bottom of the key button 130 so that the printing surface can be checked even at night. When the light is irradiated from the light source, the user can easily recognize the numbers or letters printed on the key button 130 by the backlighting effect.

However, the conventional top view LED type light emitting keypad used as a light source of the light emitting keypad has a relatively thick keypad. In addition, the uniformity of light emission is uneven depending on the arrangement position of the LED, which leads to design difficulties.

In order to overcome the limitation of ultra-thinning of the conventional LED light emitting keypad, a slim type light emitting keypad to which an EL (Electro Luminescence) lamp light emitting method (hereinafter referred to as an 'EL method') has been developed.

2 is a cross-sectional view of a conventional EL type light emitting keypad for solving the above problems, and includes a key top 210, an EL metal dome sheet 220, and a printed circuit board 230, and the EL metal dome sheet 220. ) Is composed of an EL sheet 221, a metal dome 223, and a base tape 222 to realize ultra-thin film and low power consumption.

Looking at the function of the EL-type metal dome keypad, when the key top 210 is pressed by the user, the fixed contact of the metal dome 223 and the printed circuit board 230 by the projection 211 located at the rear of the key top 210. Terminal 231 is contacted and switched on to operate.

Such an EL type light emitting keypad has the advantage of providing uniform surface light emission, but there is a problem of noise generation, which may cause a malfunction. In addition, the EL method is an AC device, and since circuit components such as an inverter and an inductor must be essentially configured, there is a problem that a mounting space problem and an additional cost problem occur.

Accordingly, there is a need for the development of a light emitting keypad that can comprehensively solve the above problems.

The present invention is to solve the above problems, to implement the LED method, but not in the top view method, but in the side view method, to provide a slim light emitting keypad by guiding the surface light through a slim waveguide film. It aims to do it.

In addition, by forming an upper projection instead of a lower projection on the rear layer, the damage of the waveguide film can be minimized to improve reliability, and a light emitting keypad having high light emission efficiency is formed by forming an emission pattern in a predetermined region on the rear layer and the upper projection. It aims to provide.

Moreover, it aims at forming a dot pattern in a waveguide film, aiming at uniform surface light emission, and increasing the light emission luminance of a specific region.

In addition, it is an object to include a phosphor in the dot pattern to increase the light emission luminance, to change the light emission wavelength, and to emit light in various colors as necessary.

It is also an object of the present invention to provide a method of forming the dot pattern in a more effective and higher yield.

The present invention for achieving the above object,

A key plate on which a plurality of keys are formed; A rear layer disposed below the keypad and provided with a plurality of upper protrusions to correspond to all or a part of the keys; And a waveguide film formed under the rear layer and guiding surface incident light from the light source, wherein the waveguide film has a dot (DOT) pattern for increasing luminance in a predetermined area of an upper surface or a rear surface thereof. Provided is a light emitting keypad.

In addition, the light emitting keypad is characterized in that the light emission pattern is formed on a predetermined region of the upper surface of the rear layer and the upper surface of the upper projection.

In addition, a part or all of the dot pattern is provided with a light emitting keypad, characterized in that the phosphor for increasing the brightness.

In addition, a part or all of the dot pattern is provided with a light emitting keypad, characterized in that the phosphor for changing the wavelength of the light to a long wavelength.

In addition, the phosphor provides a light emitting keypad, characterized in that at least one selected from the YAG-based, TAG-based, silicate-based phosphor is used.

In addition, the light incident surface of the waveguide film provides a light emitting keypad, characterized in that the bending pattern is formed.

In addition, the dot pattern is coupled to the center of the elastic mesh, and provides a light emitting keypad, characterized in that formed in a printing method using a metal mask machined holes corresponding to the dot pattern.

In addition, the light emitting keypad is located on the bottom of the waveguide film, and further comprising a printed circuit board having a dome switch.

The present invention also provides a waveguide film for a light-emitting keypad for guiding the surface incident light from the light source, the waveguide film is a dot (DOT) pattern is formed in a predetermined region on the upper surface or the rear surface, the dot pattern Silver is bonded to the center of the elastic mesh, and provides a waveguide film for a light-emitting keypad, characterized in that formed by a printing method using a metal mask machined holes corresponding to the dot pattern.

In addition, a part or all of the dot pattern provides a waveguide film for a light-emitting keypad, characterized in that the phosphor to increase the brightness while changing the wavelength of light to a long wavelength.

Hereinafter, the present invention will be described in more detail with reference to the drawings and examples.

3 is a cross-sectional view of a light emitting keypad having a waveguide film according to an embodiment of the present invention. As shown, a key plate 10 having a plurality of keys formed thereon, a back layer 20 having a plurality of upper protrusions 21 positioned below the key plate 10 and corresponding to all or part of the keys, and A waveguide film 30 formed under the rear layer 20 and guiding the light incident from the light source 50 to emit light. The waveguide film 30 has a predetermined region on an upper surface or a rear surface thereof. The light emitting keypad is characterized in that the dot (DOT) pattern 31 is formed to increase the brightness. A printed circuit board 40 having a dome switch having a metal dome 41 and a contact terminal 42 may be disposed below the waveguide film 30. The light source 50 is not limited, but LEDs are most preferred, and blue LEDs are preferable.

The light emitting keypad according to the present invention solves the problem of slimming due to the adoption of a conventional top-view light source using a side-view light source, and uses a waveguide film with a dot pattern for increasing luminance to uniform surface light emission and / or a specific area. High brightness can be achieved.

The keypad 10 may be applied without being limited to the keypad of the light emitting keypad, and the present invention does not limit the shape and material of the keypad. That is, each key of the keypad may be formed convexly, or may be formed of a flat plate and each key may be represented only by letters or numbers corresponding to the respective keys. Since it is well known in the art, detailed description thereof will be omitted.

Preferably, the keypad 10 may be made of a transparent flat sheet in which the keys are integrally formed. In addition, the keys may be expressed through the ink layer printing on the lower portion of the keypad, and the area except the keys may be colored by providing a colored deposition layer. In addition, the keypad may be formed with a protective coating layer to prevent scratches on the upper surface.

The back layer 20 includes a plurality of upper protrusions 21, but is not limited thereto, but may be integrally formed. The back layer may have excellent elastic restoring force, and the material may be silicon. The back layer and the upper projections are not limited but may be easily formed by the molding die.

The upper protrusion 21 may be formed in a number to correspond to the position of all or a part of the key of the keypad of the light emitting keypad, when the key is pressed by the user the upper protrusion is pressed to the back corresponding to the position of the upper protrusion The layer area is selectively bent to cause electrical connection at the switching portion of the dome switch or the like that will be below the waveguide film. The back layer has elastic restoring force and is restored to its original state when the user releases the pressing of the key.

When the lower protrusion is formed at the bottom of the back layer, the lower protrusion may repeatedly pressurize the waveguide film to cause damage to the waveguide film. Therefore, by forming the upper projection on the top of the back layer, it is possible to minimize the damage by dispersing the pressure received by the waveguide film without reducing the click feeling of the key.

Although the waveguide film 30 is not limited, polycarbonate, polyethylene terephthalate, acrylic film, etc. having excellent optical transparency may be used, and when considering slimming, light guide efficiency, and click feeling of the dome sheet, 50 to 200 A thickness of mu m is preferred. The waveguide film is bonded to the back layer. Primer treatment is recommended to increase adhesion. For example, after the primer is applied to the waveguide film, silicon may be poured into a mold to be thermally treated to form a rear layer, and at the same time, the waveguide film may be bonded.

The dot pattern 31 is formed on an upper surface or a rear surface of the waveguide film 30. The dot pattern plays various roles. By forming the dot pattern, the light emission luminance of the region is increased. Therefore, as the dot pattern moves away from the light source, the surface of the dot pattern may be denser or increase in size, thereby obtaining uniform surface light emission. In addition, when the dot pattern is concentrated in a specific area, for example, an area of the position of the key, light emission is concentrated in the area of the key, so that the luminance is increased than the other area. In the case of the light-emitting keypad, it is more preferable to concentrate the dot pattern on the key area because light emission of the key area is important. However, the uniform dot pattern is not excluded from the present invention.

It is preferable that the said dot pattern is formed using curable resin composition. In particular, when using the curable resin composition excellent in hardness can be minimized the damage of the dot pattern. A well-known curable resin composition can be used as curable resin composition, A photocurable resin composition is especially preferable, A photoinitiator may be further included. In one example, an acrylic resin composition may be used. That is, the curable resin composition may be selectively applied to a position of a dot pattern and then cured.

Part or all of the dot pattern 31 may preferably include a phosphor for increasing luminance. In addition, the phosphor may be a phosphor that increases the brightness while changing the light wavelength of the light source to a long wavelength. The content of the phosphor is not limited, but is preferably 5 to 20 parts by weight based on 100 parts by weight of the total solid of the dot pattern.

The phosphor may be used as long as it satisfies the above conditions, and is not limited. For example, Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn, (La, Mn, Sm) ₂ O ₂ S.Ga ₂ O ₃ is red. As the phosphor, ZnS: Cu, Al, SrAl ₂ O ₄ : Eu, BAM: Eu, Mn are green phosphors, YAG: Ce is a yellow phosphor, BAM: Eu, Sr ₅ (PO ₄ ) ₃ Cl: Eu, ZnS : Ag, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu can be used as a blue phosphor. And these fluorescent substance can also be used in combination. White light emission may be achieved by combining the phosphors.

As the white phosphor, an oxynitride glass phosphor (see Japanese Patent Application Laid-Open No. 13-214162), a phosphor based on sialon (see Japanese Patent Application Laid-Open Nos. Hei 15-336059, Hei 15-124527), and silicon nitride Phosphors containing nitrogen such as the system (see Japanese Patent Laid-Open No. 15-515655 and Japanese Patent Laid-Open No. Hei 15-277746) can be used.

Preferably, at least one selected from YAG series, TAG series, and silicate series is used. One example of YAG series is Ce ^{3 +} Dope Y ₃ A _l5 O ₁₂ , one example of TAG series is Ce ^{3 +} Dope Tb ₃ A _l5 O ₁₂ , and one example of silicate series is Eu ^{2 +} Dope (SrBaCa) ₂ SiO ₄ Si: Al, B, P, Ge, Eu 2 + Dope (SrBaMg) 2 SiO 4 O: and the like F, Cl, N, s, it is recommended that at least one selected from the.

When phosphors having different emission wavelengths are differently added to the dot patterns for each region, light having different wavelengths is emitted for each region, thereby achieving a visual effect.

4 is a view showing a mask used in an example of a method of forming the dot pattern 31 according to an embodiment of the present invention, Figure 5 is a plan view of a waveguide film according to an embodiment of the present invention, It is a figure which shows the waveguide film produced by the said method.

The dot pattern 31 may be manufactured by various methods, but is not limited thereto. The waveguide film is a very thin film, and the method of forming a pattern by applying heat using a hot press method or the like may cause deformation of the film and the production yield is relatively low. Also, ordinary screen printing methods are insufficient to form a desired dot pattern. Therefore, it is preferable to form using the mask shown in FIG. That is, it is good to be formed by a printing method using a metal mask bonded to the center of the elastic mesh, the hole corresponding to the dot pattern is processed. However, the hot press method and the screen printing method are not excluded from the present invention.

The mask includes an elastic mesh 60 and a metal mask 61 bonded to the center of the mesh and having holes 62 corresponding to dot patterns. As a method of processing a hole in the metal mask, a chemical etching method, a laser etching method, or the like can be used.

When the printing using the mask is stretched mesh is stretched during printing to be in close contact with the waveguide film, the curable resin composition is injected into the fine hole formed in the metal mask to form a dot pattern. Various dot shapes are made according to the shape of the hole, and for example, various dot shapes such as a square, a rhombus, and the like may be manufactured.

The mesh is not limited but is preferably a mesh of 80 to 400 mesh as polyester mesh.

The size of the formed dot is not limited, but 80 ~ 200㎛ is good, can be produced at intervals of 100 ~ 800㎛, the thickness (height) of the dot is suitable 5 ~ 30㎛.

A lower portion of the waveguide film 30 may be coupled to a printed circuit board 40 having a dome switch positioned to correspond to an upper protrusion. The dome switch may be connected to the contact terminal 42 and the upper portion of the contact terminal. It is preferable that the metal dome (41) is located spaced apart from the contact terminal. The metal dome is a good elastic material is good for improving the clickability.

Therefore, when the keypad of the keypad is pressed by the user, the metal dome of the printed circuit board provided under the specific key is pressed so that the metal dome contacts and contacts the contact terminal.

The assembly of the keypad is not limited, but in order to improve the alignment, it is preferable to first assemble the printed circuit board equipped with the dome switch and the back layer to which the waveguide film is bonded, and then assemble the keypad.

6 is a cross-sectional view of a light emitting keypad according to another embodiment of the present invention. As shown, the light incident surface of the waveguide film 30 is characterized in that the bending pattern 32 is formed. The bending pattern is formed on the light incident surface, thereby preventing a part of the light from being reflected from the waveguide film light incident surface and allowing light to be received more efficiently.

7 is a cross-sectional view of a light emitting keypad according to another embodiment of the present invention. As illustrated, the light exit pattern 22 is formed on a predetermined region of the rear layer 20 and an upper surface of the upper protrusion 21. The area where the light exit pattern is formed may be a position of a key of the light emitting keypad. The light exit pattern may be convex or concave, but is not limited thereto. The pattern forming method may be conveniently formed by a molding or hot pressing method. The light loss may be minimized by total reflection from the top surface of the rear layer or the top surface of the protrusion through the light emission pattern.

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.

The light emitting keypad having the waveguide film according to the present invention can realize the slimming by guiding the light through the slim waveguide film to make the surface light-emitting, and by forming the upper projection on the back layer instead of the lower projection, damage to the waveguide film Reliability can be improved by minimizing the amount of light, and the light emission efficiency can be improved by forming a light emission pattern in a predetermined area of the rear layer and the upper protrusion, and a dot pattern is formed on the waveguide film to achieve uniform surface light emission, It is possible to increase the light emission luminance, to include the phosphor in the dot pattern to increase the light emission luminance, to change the light emission wavelength, and to emit light in a variety of colors as needed, the dot pattern in a more effective and high yield It provides a method of forming.

Claims (10)

delete A key plate on which a plurality of keys are formed; A rear layer disposed below the keypad and provided with a plurality of upper protrusions to correspond to all or a part of the keys; And And a waveguide film formed under the rear layer and guiding surface incident light from the light source. The light emitting keypad, characterized in that the light emission pattern is formed on a predetermined region of the upper surface of the back layer and the upper surface of the upper projection. The method of claim 2, wherein the waveguide film is formed with a dot (DOT) pattern for increasing the brightness in a predetermined area of the upper surface or the rear, and part or all of the dot pattern includes a phosphor for increasing the brightness. Luminous keypad. A key plate on which a plurality of keys are formed; A rear layer disposed below the keypad and provided with a plurality of upper protrusions to correspond to all or a part of the keys; And And a waveguide film formed under the rear layer and guiding surface incident light from the light source. A light emitting keypad, characterized in that part or all of the dot pattern includes a phosphor for changing the wavelength of light to a long wavelength. The light emitting keypad according to claim 4, wherein the phosphor is selected from at least one of a YAG series, a TAG series, and a silicate series. A key plate on which a plurality of keys are formed; A rear layer disposed below the keypad and provided with a plurality of upper protrusions to correspond to all or a part of the keys; And And a waveguide film formed under the rear layer and guiding surface incident light from the light source. Light-emitting keypad, characterized in that the light incident surface of the waveguide film is formed with a curved pattern. The method according to any one of claims 3 to 5, wherein the dot pattern is bonded to a central portion of the stretchable mesh and formed by a printing method using a metal mask having holes formed therein corresponding to the dot pattern. Light emitting keypad. The light emitting keypad according to any one of claims 2 to 6, further comprising a printed circuit board positioned below the waveguide film and having a dome switch. delete A waveguide film for a light emitting keypad for guiding the surface of the light incident from the light source, the waveguide film is a dot (DOT) pattern is formed to increase the brightness in a predetermined area of the upper surface or the rear surface, The dot pattern is bonded to a central portion of the stretchable mesh, and is formed by a printing method using a metal mask in which holes corresponding to the dot pattern are processed, and part or all of the dot pattern is changed while the wavelength of light is changed to a long wavelength. Waveguide film for a light-emitting keypad, characterized in that containing a phosphor to increase the brightness.

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