KR100762711B1 - El device for a light emitting keypad - Google Patents

Abstract

An EL(Electro Luminescence) device for a light emitting keypad is provided to prevent the formation of intaglio and easily couple a key plate and the EL device by installing a through protrusion. An EL device(30) for a light emitting keypad, which has a key plate with a through hole, includes a protective layer(20). The protective layer(20) includes a plurality of upper protrusions(21) which are protruded upwardly at the upper part of the EL device(30) to improve the clicking of a key, and a through protrusion which penetrates the through hole. At the lower part of the EL device(30), a plurality of metal domes are adhered. At the lower part of the EL device(30), a dome substrate with the plural metal domes is adhered.

Description

EL device for light emitting keypad {EL Device For a Light Emitting Keypad}

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 showing an EL device for a light emitting keypad according to an embodiment of the present invention;

4 is a cross-sectional view showing an EL device for a light emitting keypad according to another embodiment of the present invention;

5A and 5B are cross-sectional views illustrating EL devices for light emitting keypads according to still another embodiment of the present invention;

6A and 6B are cross-sectional views illustrating EL devices for light emitting keypads according to still another embodiment of the present invention;

7A and 7B are cross-sectional views illustrating a light emitting keypad to which an EL device according to the present invention is applied.

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

11: keyboard

12: ink layer

13: back layer

20: protective layer

21: upper projection

22: through protrusion

30: EL device

40: metal dome

41: dome board

42: contact terminal

43: printed circuit board

The present invention relates to EL devices for light emitting keypads.

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 LED type light emitting keypad used as a light source of the light emitting keypad cannot be manufactured in a thin shape 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. Accordingly, in order to overcome the limitation of ultra-thinning of the conventional LED type light emitting keypad, there is a demand for the development of a slim type light emitting keypad to which an EL (Electro Luminescence) lamp light emitting method (hereinafter referred to as an 'EL method') is applied.

FIG. 2 is a cross-sectional view of a conventional EL light emitting keypad for supplementing the above problem, and includes a key top 210, an EL metal dome sheet 220, and a printed circuit board 230. The 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.

However, in the conventional EL type light emitting keypad, the EL sheet 221 is continuously pressed and impacted by the projections 211, 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 causing the keypad. There is a problem that causes a drop in the feeling of clicking, and development of an EL device structure that can solve this problem is required.

The present invention is to solve the above problems, a projection for improving the clickability is formed in the upper direction, it is possible to prevent the protrusion of the EL device to directly press the EL device can prevent the EL device from being deformed, broken An object of the present invention is to provide an EL device for a light emitting keypad.

In addition, through protrusions may be provided as necessary to prevent the light emitted from the EL device from being reflected and interfered, thereby preventing the formation of intaglio, and allowing the light to pass through as it is, and it may be easier to combine the keypad and EL device. An object of the present invention is to provide an EL device for a light-emitting keypad.

The present invention for achieving the above object,

An EL device for use in a light-emitting keypad having a keypad, wherein a protective layer is provided on the EL device, the protective layer having a plurality of upper protrusions protruding upward to improve the clickability of the key. An EL device for a light emitting keypad is provided.

In addition, in an EL device used in a light emitting keypad having a key plate having a through hole formed therein, a plurality of upper protrusions and the through holes protruding upward in order to improve the clickability of a key on the upper part of the EL device. Provided is an EL device for a light emitting keypad characterized in that a protective layer having a through protrusion for penetrating is formed.

In addition, the EL device provides a EL device for a light emitting keypad, characterized in that a plurality of metal domes are bonded below.

In addition, an EL device for a light emitting keypad is provided below the EL device, wherein a dome substrate having a plurality of metal domes integrally formed is bonded thereto.

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

3 is a cross-sectional view of an EL device for a light emitting keypad according to an embodiment of the present invention. As shown, in the EL device used in the light-emitting keypad provided with the keypad, a plurality of upper projections 21 protruding upward to improve the clickability of the key on the upper part of the EL device 30. It characterized in that the protective layer 20 provided with.

EL device for a light emitting keypad according to the present invention is formed with a projection for improving the clickability in the upper direction to prevent the projection directly press the EL device to prevent the EL device from being deformed, broken.

The protective layer 20 and the upper protrusion 21 is not limited, but is preferably formed integrally, the silicon material is good. The protective layer may serve to buffer the upper protrusion directly pressurizing the EL device, and may also serve to prevent damage due to penetration of moisture, oxygen, etc. into the EL device.

The upper protrusion 21 may be formed in a number corresponding to the key position of the keypad of the light emitting keypad, and when a key is pressed by the user, the upper protrusion is pressed and thus the dome switch, etc., which will be located under the EL device. Switching takes place in a switching unit (not shown).

The structure of the EL device 30 can be applied without limitation as long as it is a structure in which an inorganic or organic light-emitting body emits light by applying an electric field, and is included in the present invention, and description thereof will be omitted. As an example, the following configuration is suitable. That is, the EL device preferably includes an insulating layer, a front electrode layer, a light emitting layer, a dielectric layer, a back electrode layer, and an insulating layer. The front electrode layer, light emitting layer, dielectric layer and back electrode layer form an EL system which is a light emitting structure of the EL device. The EL device 13 is preferably formed by screen printing for slimming.

4 is a cross-sectional view of an EL device for a light-emitting keypad according to another embodiment of the present invention. As shown, in an EL device for use in a light emitting keypad having a key plate with a through hole formed therein, a plurality of upper portions protruding upwards to improve the clickability of a key on the upper portion of the EL device 30. The protective layer 20 is provided with a protrusion 21 and a through protrusion 22 for penetrating the through hole. The same configuration as the EL device for light-emitting keypad described above will be omitted.

A through hole may be formed in the keypad (not shown), and the protective layer may further include a through protrusion 22. In particular, the through protrusion 22 may be formed to correspond to the boundary of each key. Through this configuration, it is possible to selectively press a specific key more easily, and the click feeling is improved. In addition, by forming and combining the through protrusions, the light emitted from the EL device may be prevented from being reflected and interfered with the intaglio, and the light may be transmitted as it is. Also, it is easier to combine the keypad and EL device.

5A and 5B are cross-sectional views of EL devices for light emitting keypads according to another embodiment of the present invention. As shown, a plurality of metal domes 40 are bonded to the lower EL device described above.

That is, in the light emitting keypad, a dome switch is introduced for a feeling of click and more reliable switching. The dome switch is formed of a metal dome and a contact terminal formed under the dome switch. Contact terminals are generally formed on a printed circuit board. The metal dome may be attached to the printed circuit board, but may be bonded to the lower portion of the EL device as shown. The bonding method is not limited, but it is better to simply bond using a double-sided tape or the like.

When the EL device having the above structure is assembled during manufacturing of the light emitting keypad, the flexible protective layer and the EL device are changed to the structure shown in FIGS. 7A and 7B.

6A and 6B are cross-sectional views of EL devices for light emitting keypads according to yet another embodiment of the invention. As shown, the dome substrate 41 in which a plurality of metal domes 40 are integrally formed is bonded to the lower EL device. In this way, by forming a plurality of metal domes integrally, manufacturing can be made simpler. A printed circuit board having a contact terminal is positioned below the dome substrate. The metal dome is a good elastic material is good for improving the clickability.

7A and 7B are cross-sectional views of a light emitting keypad to which an EL device according to an embodiment of the present invention is applied. A key board 11, an ink layer 12, a back layer 13 (which may be omitted), and the like may be formed of a printed circuit board having EL devices and contact terminals according to an embodiment of the present invention.

When applying the present invention, the upper protrusion formed on the protective layer is directed upward, it is possible to prevent the EL device under the protective layer from being damaged.

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.

EL device for a light emitting keypad according to the present invention is a projection for improving the clickability is formed in the upper direction to prevent the projection directly press the EL device can prevent the EL device is deformed, damaged, The through projections are provided to prevent the light emitted from the EL device from being reflected and interfered, thereby preventing the formation of the intaglio and allowing the light to pass through as it is, and it becomes easier to combine the keypad and EL device.

Claims (4)

delete In the EL device used for a light-emitting keypad having a key plate formed with a through hole, EL device for a light emitting keypad, characterized in that a protective layer having a plurality of upper protrusions protruding upward and through holes for penetrating through the through holes is formed on the EL device to improve the clickability of the key. The EL device of claim 2, wherein a plurality of metal domes are bonded to the lower portion of the EL device. The EL device of claim 2, wherein a dome substrate having a plurality of metal domes integrally bonded to the EL device is bonded thereto.

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