KR200325935Y1 - Keypad with an integrated driving circuit of electroluminescence - Google Patents

Abstract

The keypad design with EL lamp and the EL lamp driving circuit for driving the EL lamp are manufactured in a single package, and the EMI design is performed outside the EL lamp driving circuit or inside the keypad to design and manufacture the circuit board of the PCB. The present invention relates to a keypad integrated with an EL lamp driving circuit that can easily reduce the noise, and can reduce electromagnetic interference and noise and vibration generated when the EL lamp driving circuit is operated.

Such an EL lamp driving circuit-integrated keypad is installed on the front housing of a telephone in a state located on a printed circuit board having a contact point and used as a key for generating a signal, and in a keypad for a mobile phone provided with an EL lamp providing backlighting to the key, The keypad provides an EL lamp driving circuit-integrated keypad comprising an EL lamp and an EL lamp driving circuit for operating the EL lamp in a package form.

The driving circuit is formed of a package in which a plurality of components constituting the driving circuit are combined into one unit, and the driving circuit is selectively installed among upper, side, and bottom of the EL lamp while being electrically connected to the EL lamp. do.

Description

KEYPAD WITH AN INTEGRATED DRIVING CIRCUIT OF ELECTROLUMINESCENCE}

The present invention relates to a keypad, and more particularly, a keypad in which an EL lamp is applied and an EL lamp driving circuit for driving the EL lamp are manufactured in the form of a package in a single unit, and the outside of the EL lamp driving circuit or the inside of the keypad. The present invention relates to a keypad integrated with an EL lamp driving circuit that can easily design and manufacture a circuit board of a PCB board by EMI treatment, and can reduce electromagnetic interference, noise and vibration generated when the EL lamp driving circuit is operated.

In general, the keypad is applied to a communication device such as a mobile phone, and is used as a switch device for generating a signal and performing various additional functions. The switch device has a key printed with numbers or letters. It is fitted into a hole provided in the front housing of the communication device has a structure protruding part of the front housing outside.

The key constituting the keypad is formed with a printed surface on which numbers or letters are displayed as described above, and checks the numbers or characters displayed on the printed surface and presses a desired key.

A light source made of a light emitting element is installed outside the bottom of the key so that the printed surface can be checked at night. When the light is irradiated from the light source, the user can recognize the number or letter printed on the key by the backlighting effect. Consists of.

In general, the light source mainly uses LED lamps, and the LED lamps have a disadvantage in that brightness is wide because the light is wide and not evenly irradiated, and only light is irradiated only around the LED lamps.

Therefore, in recent years, as one method for providing backlighting evenly over a wide range, a keypad using a sheet-shaped EL element (hereinafter referred to as "EL lamp") as a surface light-emitting body as a light source of a keypad has been manufactured. have.

The conventional structure of this EL lamp consists of a cathode and an anode electrode, an inorganic light emitting body and a substrate, and a driving circuit composed of a transistor, a resistor, a capacitor, an inverter, and the like is provided for driving such an EL lamp.

The driving of the EL lamp is configured such that when the power is applied to the driving circuit through the device provided with the EL lamp, the EL lamp emits light by converting the driving circuit into a high voltage necessary for driving the EL lamp and supplying it to the EL lamp.

However, in the conventional keypad provided with such an EL lamp, since each component of the EL lamp driving circuit for driving the EL lamp is separately installed on the PCB, the design and manufacture of the PCB circuit are difficult and complicated. .

In addition, there is a disadvantage that electromagnetic interference, noise and vibration are generated in the inverter of the driving circuit installed on the PCB when the EL lamp is driven.

The present invention has been made to solve the conventional problems as described above, the object of the present invention is to produce a package in which the EL lamp keypad and the EL lamp driving circuit for driving the EL lamp combined into a single unit. In addition, EMI treatment is applied to the outside of the EL lamp driving circuit or to the inside of the keypad to facilitate the circuit design and fabrication of the PCB board, and to reduce the electromagnetic interference, noise and vibration generated during the operation of the EL lamp driving circuit. The present invention provides a keypad integrated with an EL lamp driving circuit.

In order to realize the object of the present invention as described above, the mobile phone is installed on the front housing of the telephone and used as a key for signal generation in a state located on the printed circuit board having the contact point, and the EL lamp is provided to provide backlighting on the key In the keypad for use, the keypad provides an EL lamp driving circuit-integrated keypad characterized in that the EL lamp and the EL lamp driving circuit for operating the EL lamp are connected in a package form.

The driving circuit is independently installed in a predetermined space of the keypad in connection with the EL lamp irrespective of the installed position of the EL lamp, and is provided with EMI (electromagnetic interference) processing outside the driving circuit.

1 is a cross-sectional view of a keypad showing an embodiment of a keypad integrated with an elamp driving circuit according to the present invention.

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

Fig. 1 is a sectional view showing a keypad integrated with an EL lamp driving circuit according to the present invention. The keypad of this embodiment shows that the key is made of plastic as an example.

As shown, the keypad according to the present invention includes a base 2 and a plurality of keys 4 fixedly installed on the base 2.

The base 2 may be made of silicone rubber or the like, and has a structure in which a protrusion 6 is formed at a portion corresponding to the center of the key 4 in the lower portion of the base 2.

The key 4 may be a plastic key made by injecting a thermoplastic resin such as polycarbonate, ABS resin, or acrylic resin of a transparent material, or a plating key coated with a metal material on the surface of the plastic key, or a mixture thereof. Keys can be used.

And the key 4 is formed with a printing surface (not shown) made of letters, numbers, etc. is configured so that the user can press the desired key.

The key 4 is bonded to the base 2 and the adhesive 5, and is integrally formed. The base 2 constituting the keypad provides backlighting on the keypad so that the printing surface of the key can be checked even in a dark place. A sheet-shaped EL lamp 8 made of a luminous body is provided.

The EL lamp 8 typically has a structure consisting of electrodes of a cathode and an anode, an inorganic light emitting body, and a substrate, and the EL lamp 8 may be used in general, and thus a detailed description thereof will be omitted.

In addition, a driving circuit 10 is provided to drive the EL lamp 8, which has an input terminal and an output terminal, and the input terminal (not shown) is electrically connected to a battery provided to a communicator such as a cellular phone. The output terminal 12 of the driving circuit 10 is electrically connected to the cathode electrode and the anode electrode of the EL lamp 8.

The driving circuit 10 according to the present invention is formed in a package form in which components such as transistors, resistors, capacitors, and inverters constituting the driving circuit are combined into a single unit, and the outer side of the driving circuit 10 packaged in this way Electromagnetic Interference (EMI) processing 14 is provided to prevent interference with normal signal transmission of the electronic circuit due to the influence of electromagnetic waves generated when the driving circuit 10 is driven.

Since the EMI treatment 14 may be processed by a commonly used method, a detailed description thereof will be omitted.

When the EL lamp driving circuit 10 manufactured in the form of a package and subjected to EMI treatment 14 is installed on the keypad, the driving circuit when the EL lamp 8 is driven by the sealing of the driving circuit 10 and the EMI treatment 14 or the like. It is possible to suppress electromagnetic waves, electrical noise and vibration inevitably generated in the furnace 10, and to install PCBs, such as transistors, resistors, capacitors, and inverters, each of which constitutes a driving circuit on a conventional PCB. The circuit design can be simplified.

The EL lamp driving circuit integrated keypad of the present invention can be applied to display devices of electronic devices and communication devices. When such a keypad is provided in a mobile phone, for example, when a folder or flip of the mobile phone is opened, the battery power of the mobile phone is provided. This EL lamp driving circuit 10 is supplied.

When the driving circuit 10 converts the high voltage necessary for light emission of the EL lamp 8 and supplies it to the EL lamp, electrons and holes recombine and emit light, thereby providing backlighting to the keypad. Lets you see the printed surface, such as numbers or letters formed in).

At this time, the electromagnetic wave, electrical noise and vibration inevitably generated in the driving circuit 10 when the EL lamp 8 is driven by the sealing of the driving circuit 10 and the EMI treatment 14 can be suppressed. Pressing (4), the base (2) and the projection (6) located at the bottom of the key (4) overcome the elastic force of the dome switch installed on the printed circuit board (not shown) and invert the dome switch downward while Contact to generate a signal.

When the signal 4 is generated and then released from the key 4, the key 4 is returned to its original position by the elasticity of the dome switch and the base 2.

After using the mobile phone, closing the folder or flip the battery power supplied to the EL lamp driving circuit 10 is cut off and the backlighting of the EL lamp 8 is stopped.

In the above embodiment, the base 2 and the key 4 constituting the keypad are made of silicone rubber and plastic, and the EL lamp 8 and the EL lamp driving circuit 10 are provided as an example by way of example. However, even when the base and the key top constituting the keypad is made of different materials, for example, silicone rubber and synthetic resin, the embodiment of the present invention can be applied in the same way.

As described above, the keypad integrated with the EL lamp driving circuit according to the present invention is provided with an EL lamp driving circuit for driving the EL lamp in a package form. Compared to the structure in which each component of the driving circuit is separately installed on the PCB, it is easier to design and manufacture the PCB.In addition, when the EL lamp driving circuit is sealed and EMI processed, Inevitable electrical noise and vibration can be suppressed.

Claims (3)

In a keypad for a mobile phone installed in a front housing of a telephone and placed on a printed circuit board having a contact point and used as a key for signal generation, and provided with an EL lamp providing backlighting on the key, the keypad includes an EL lamp and the EL lamp. EL lamp driving circuit-integrated keypad, characterized in that the EL lamp driving circuit for operating the lamp is provided connected to the package. The keypad of claim 1, wherein the driving circuit is independently installed in a predetermined space of the keypad in a state of being connected to the EL lamp regardless of the installed position of the EL lamp. The keypad of claim 1, wherein an EMI (electromagnetic interference) process is formed outside the driving circuit.