KR200460797Y1 - Keypad device with superimposed keyboard - Google Patents

Abstract

The display panel is formed so that the light guide plate and the character display unit are connected to each other so as to overlap each other in the vertical direction, and a liquid crystal panel is provided between the layers to act as an optical shield due to the change in transparency depending on whether voltage is applied. Disclosed is a keypad device having a superimposed keyboard. In this case, a polymer dispersed liquid crystal (PDLC) may be used for the liquid crystal panel.
According to the present invention, a character inputted by a single button on a keypad of a mobile communication terminal having a limited area is variously changed according to a user's needs, and the number of buttons and the keypad area can be kept small while various characters can be displayed with a single button. Since input can be prevented, errors due to button interference during input can be prevented, the efficiency of input work can be improved, and user fatigue due to input work can be reduced.

Description

Keypad apparatus having overlaid key board

The present invention relates to a keypad device having a superimposed keyboard, and in particular, a keyboard for expressing various characters (including symbols) and numbers (hereinafter referred to as 'characters', etc.) according to a user's needs. My same location button relates to a keypad device that allows input of different letters or numbers by selection.

Mobile communication terminals, called mobile phones and cellular phones, have been developed to perform various functions such as video call function, Internet access function, TV reception function, camera function, portable memory function, infrared communication function, etc., in the conventional simple call function.

As such, as various functions can be implemented by mobile terminals, consumer dependence on mobile terminals increases, and it is a major technical trend of the industry to include more functions in mobile terminals. It became.

In the case of a smart phone, a representative mobile communication terminal according to such a trend, a personal computer and its accompanying functions can be maintained while maintaining the unique characteristics, appearance, and size of a mobile phone, and various letters or numbers are moved to suit such computer functions. It is necessary to be displayed on the keypad of the communication terminal.

1 is a cross-sectional view showing a schematic configuration of an example of a conventional keypad device.

The keypad device usually comprises a keypad 140 having a dial that is exposed to the outside and a circuit board 100 having a circuit which is activated when an individual button on the dial of the keypad is pressed. The circuit board is usually a flexible printed circuit board. It is made using a circuit board (FPCB). In addition, the dome switch 121 is frequently used to switch the circuit smoothly when the button is pressed. The dome switch 121 is formed on a dome sheet 120 separate from the flexible circuit board.

In addition, in recent years, a light guide plate 130, called a waveguide sheet, is widely used as illumination of a keypad device. The light guide plate receives light from an LED light installed at a side of the keypad device so that light is emitted upward from the front of the keypad or at each button position. To recognize the position of the button on the keypad dial and whether the button operates. In general, there is an actuator (123) in accordance with the button position or the dome switch position of the keypad so that the operation of the dome switch 21 is more accurately performed.

Instead of installing the dial on the keypad, the light guide plate may be directly formed on the surface of the light guide plate, and only a cover for protection may be installed on the light guide plate. For example, when the surface of the light guide plate is treated at each button position to form a light emitting part, in the light emitting part, part of the light propagated along the light guide plate is reflected or scattered to emit light upward. In this process, the characters of the keypad cover on the upper part of the light guide plate are illuminated so that when the user presses a button, the characters displayed on the keypad cover can be recognized.

However, in order to display various letters and numbers simultaneously due to its limited size, the keypad of the mobile communication terminal has a smaller size corresponding to the corresponding letters and numbers, and a typo and an input device error due to interference when pressing each button. It is easy to cause problems.

Therefore, in order to prevent such a problem requires considerable attention in button operation, in this case, the user of the mobile communication terminal due to excessive tension in the operation of the operation efficiency is reduced, the body parts such as eyes can easily feel fatigue. have.

On the other hand, increasing the keypad area of the mobile communication terminal, or providing an input unit connected to the mobile communication terminal as a separate component has a disadvantage of lowering the portability and ease of use of the mobile communication terminal as a whole deteriorate the productability.

The present invention is to solve the problems of the conventional keypad device, by installing a keyboard display layer superimposed in the keypad device of a mobile communication terminal of a limited area to vary the characters input by a single button according to the needs of the user In the keyboard of the mobile communication terminal installed so as to change, it is possible to clearly recognize the selected keyboard, to prevent errors due to button interference when entering characters, to improve the efficiency of input work, and to feel the fatigue of work An object of the present invention is to provide a keypad device of a mobile communication terminal that can be reduced.

In order to achieve the above object, the present invention provides a keypad device having an overlapping keyboard, wherein a light guide plate and a keyboard display layer formed by associated with each other are overlapped in an up and down direction, and transparency between the layers depends on whether a voltage is applied. It is characterized in that the liquid crystal panel is provided that can act as an optical shield.

Polymer Dispersed Liquid Crystal (PDLC) may be used for the liquid crystal panel in the present invention.

In the present invention, the letter display unit displays letters on a sheet separate from the light guide plate and is placed on the light guide plate so that the light from the light guide plate is transmitted through the sheet to be emitted to the outside, or applied to the surface of the light guide plate or the surface treatment method, respectively. It can be formed integrally with the light guide plate by being able to represent characters directly in combination.

In the case of forming the character display unit integrally with the light guide plate, the surface of the light guide plate is roughened to form a letter or number shape so that the light touching or reflecting the part is reflected or scattered so that the light flows out of the light guide plate to directly display the shape of the letter or number. Alternatively, a material with good reflection on a rough surface may be applied in the form of letters or numbers so that light is reflected in this portion so that the shape of letters or numbers is displayed above the light guide plate.

According to the present invention, a character inputted by a single button on a keypad of a mobile communication terminal having a limited area is variously changed according to a user's needs, and the number of buttons and the keypad area can be kept small while various characters can be displayed with a single button. Since input can be prevented, errors due to button interference during input can be prevented, the efficiency of input work can be improved, and user fatigue due to input work can be reduced.

1 is a cross-sectional view showing a schematic configuration of an example of a conventional keypad device.
2 is an exploded cross-sectional view showing a schematic layer configuration of the superstructure excluding a circuit portion in one embodiment of the keypad device of the present invention.
Figure 3 is a cross-sectional view showing the configuration of a liquid crystal panel that can be used in one embodiment of the keypad device of the present invention.
Figure 4 is a cross-sectional view of the light guide plate showing another embodiment of the character display portion of the keypad device of the present invention.
Figure 5 is an exploded perspective view schematically showing an upper structure in another embodiment of the keypad device of the present invention,
6 is a cross-sectional view of the coupled state of the structure shown in FIG.

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

FIG. 2 is a view of a liquid crystal panel positioned on a first keyboard display layer 10 and a first keyboard display layer including a first light guide plate 11 in which the first letter display unit 12 is integrally formed in an embodiment of the present invention. 30, a second keyboard display layer 20 having a second light guide plate 21 disposed above the liquid crystal panel and integrally provided with the second character display unit 22, and protecting the lower layers on the second keyboard display layer. It is a side sectional view which shows the keypad device which is provided so that the cover layer 40 may overlap.

The first keyboard display layer 10 at the bottom of the overlapping keyboard display layers 10 and 20 is irregular by forming a fine reflective surface on the surface or roughening the surface according to a character shape on the bottom of the first light guide plate 11. The first letter display unit 12 is formed by forming a surface, and the surface treatment may be performed on the upper surface instead of the bottom of the first light guide plate 11. In this case, unlike the other surface of the light guide plate which is totally reflected, the character display unit emits light by reflection and scattering, and the user recognizes the character of the keypad first keyboard display layer 10 through the external emission. .

The liquid crystal panel 30 is formed by using a PDLC having a property in which liquid crystals are regularly arranged and become transparent when a voltage is applied between upper and lower substrates in connection with a power source. More specifically, in the liquid crystal panel, a PDLC 34 is inserted between two transparent substrates 31 and 38 on which transparent electrode layers 32 and 36, such as indium tin oxide (ITO), are formed throughout the inner surface. And a conventional polymer dispersed liquid crystal panel 30 formed by sealing the periphery were used. Of course, power may be applied to the terminal connected to the transparent electrode layer through a switch.

Like the first keyboard display layer 10, the second keyboard display layer 20 on the upper side of the overlapping keyboard display layers 10 and 20 may be formed on the bottom surface of the second light guide plate 21 according to the shape of letters or the like. Processing to form the second character display unit 22.

Light sources 16 and 26, such as LED lamps, are provided on the side of the first light guide plate 11 and the second light guide plate 21. Character display portions of the first keyboard display layer 10 or the second keyboard display layer 20 may be selectively displayed.

Except where the LDE lamp is formed, the other peripheral side of the light guide plate is finished using the reflecting plates 14, 24 or light blocking plate. This is because light propagating along the light guide plate leaks to the outside from the side of the light guide plate to cause loss of light, and some of the leaked light enters another light guide plate, and the user can see characters of other keyboards (character display part) related to the other light guide plate. This is because the possibility of confusion about which keyboard input layer is input from among the first keyboard display layer 10 and the second keyboard display layer 20 increases.

Referring to the operation of displaying the keyboard in this configuration, first, the keypad device displays the characters of the first keyboard display layer 10 in the mode of inputting using the characters of the first keyboard display layer 10 below. In order to apply the voltage to the liquid crystal panel 30 to make it transparent, the LED lamp light source 16 on the side of the first light guide plate 11 is turned on, and the light source 26 on the side of the second light guide plate 21 is Stay off.

In this case, the light propagating along the first LGP 11 is partially reflected and scattered upward from the first letter display portion 12 of the bottom surface of the first LGP having a rough surface treatment, and the light is directed upward. Through the liquid crystal panel 30, the second light guide plate 21, and the cover layer 40, the liquid crystal panel 30, the second light guide plate 21, and the cover layer 40 are emitted to the outside in a state of representing characters of the first keyboard display layer 10 and recognized by the user. In this process, the light passes through the second character display portion 22 of the second keyboard display layer 20 on the bottom surface of the second light guide plate 21, but for the upward light, the second character display portion 22 is the first. The first keyboard display layer (10) has a scattering effect of slightly blurring characters of the keyboard display layer, but only makes the brightness slightly different from the area of the character display portion and the other regions. Characters only) are recognized by the user.

Next, in the input mode using the characters in the second character display portion 22 of the upper second keyboard display layer 20, the liquid crystal panel ( The electrical terminal of 30) is disconnected from the power source to be in an opaque state, and the LED lamp on the side of the second light guide plate 21 is turned on. At this time, it is preferable that the LED lamp on the side of the first light guide plate 11 be kept off.

In this case, light emitted from the LED lamp and propagated along the second LGP 21 is partially reflected and scattered by the second character display 22 on the bottom surface of the second LGP 21 having a rough surface, and is directed upward. This light is transmitted through only the cover layer 40 and is emitted to the outside as it is recognized by the user. In this process, some of the light may be scattered in the second character display unit 22 to go downward, and then may be reflected through the first character display unit 12 of the bottom of the first LGP, and then emitted to the outside. Blocked by the liquid crystal panel 30, the characters of the first keyboard display layer 10 is not recognized. In addition, since the surface treatment that forms the character display portion for the light reflected from the second character display portion 22 on the bottom surface of the second light guide plate toward the up or down direction does not increase the fractionation effect on other areas other than the character display portion as described above. The user of the mobile communication terminal mainly recognizes only the characters of the second keyboard display layer 20.

On the other hand, the first light source on the side of the first light guide plate has a greater amount of light than the second light source on the side of the second light guide plate so that the characters of the first keyboard display layer and the characters of the second keyboard display layer are recognized by the user with similar brightness. Alternatively, as shown in FIG. 4, surface treatment is performed on the bottom surface character display portion 12 of the first light guide plate 11, and a material layer 13 having high reflectivity is applied to the portion to display characters. You can create a keyboard display layer.

When the difference in the amount of light between the first light source and the second light source is set, the second light source is emitted from the first light source, reflected from the character display portion of the first keyboard display layer, and upwardly attenuated through the liquid crystal panel and the second light guide plate. The light emitted from the light emitting diodes may have a brightness similar to that of light upwardly reflected from the character display portion of the second keyboard display layer.

When the character display part is formed by applying a material layer 13 having high reflectivity to the area such as the character that is formed by surface treatment on the first light guide plate as shown in FIG. 4, the amount of light reflected by the character display part increases as a result. An effect similar to increasing the light quantity of the light source can be obtained.

Figure 5 and Figure 6 is an exploded perspective view and a side cross-sectional view of a coupled state showing another embodiment of the present invention.

In this embodiment, the keypad device comprises a first light guide plate 11, a first light source 16, and a liquid.

The positive panel 30, the second light guide plate 21, the second light source 26, the keypad cover layer 40, the first reflector 14, and the second reflector 24 are provided.

The first light guide plate 11 may be formed by injecting transparent synthetic resin such as polycarbonate (PC), polyurethane (PU), and polyethylene terephthalate (PET) having excellent transparency, and having a reflective property on a bottom surface thereof. Characters and the like are printed on the material to form the first character display unit 12. In the present embodiment, the Hangul consonants and vowels are displayed on the first character display unit 12, and the character display unit may be formed by various methods such as screen printing, scratch, secondary molding (UV, silicon), and the like.

When the light propagating along the light guide plate reaches the bottom character display part of the first LGP 11, the first character display part 12 is processed through surface treatment and application of a reflective material so that the reflectance is high in the direction of the keypad cover 24, that is, in an upward direction. ) Is formed, and the first light source 16 is disposed on one side of the first light guide plate 11, and when light is irradiated into the first light guide plate 11, the light is emitted upward from the first letter display unit 12 to the outside. It serves to be displayed as. The first light source 16 consists of an LED or other small lamp.

The liquid crystal panel 30 is disposed above the first light guide plate 11, and a voltage is applied to display the characters of the first character display unit 12 in the upward direction by the first light source 16. It is in a state with.

The second light guide plate 21 is disposed above the liquid crystal panel 30. The second light guide plate 21 is also made of a synthetic resin plate excellent in permeability, and a second letter display portion 22 such as numerals and letters is printed on the bottom surface of a material having a diffuse reflection characteristic.

The bottom of the second light guide plate 21 is preferably treated by forming a coating layer or processing a surface so that the reflectance is high in the cover layer 40 direction, that is, the upper direction when light is irradiated from above, and the transmittance is high when light is irradiated from below. .

The second light source 23 is disposed on the side of the second light guide plate 21, and serves to display the second letter display unit 22 to the outside by irradiating light on the side of the second light guide plate 21.

The cover layer 40 is disposed on the second light guide plate 21 and is made of a material having good transparency.

The second letter display part 22 formed on the bottom surface of the second light guide plate 21 has a higher color brightness than the color brightness of the first letter display part 12 formed on the bottom surface of the first light guide plate 11. The transparency may be higher than that of the first character display unit 12. For example, when the first character display unit 12 is dark red in color, the second character display unit 22 may be embodied in light red having high transparency and high transparency than the first character display unit 12. Preferably, the second character display unit 22 may be implemented in achromatic color with high brightness and transparency, and the first character display unit 12 may be implemented in a chromatic color with low brightness.

As described in the foregoing embodiment, the second light guide plate 21 is compared with the thickness of the first light guide plate 11 so that the characters of the first character display unit and the characters of the second character display unit may have similar brightness to the user. ), And the light intensity of the first light source 16 can be made larger than the light intensity of the second light source 26.

In this embodiment, the voltage applied to the first light source 16, the second light source 26 and the liquid crystal panel may also be operated in the same manner as the previous embodiment. Although the first light source 16 and the second light source 26 are disposed at the same level at positions 180 degrees apart from each other, they may be arranged at 90 degrees or at different levels. In this embodiment, the second LGP 21 is formed or installed to bend in a downward direction in which the second light source 26 is positioned.

The first reflector 14 and the second reflector 24 are assembled with the first light guide plate 11, the liquid crystal panel 30, the second light guide plate 21 and the cover layer 40 as shown in the drawing. As in the previous embodiment of FIG. 2, the first light guide plate 11 and the second light guide plate 12 may be combined with each other, and then laminated and assembled. Instead of the reflecting plate, a material such as tape or ink may be applied to the side of the light guide plate as a light blocking member for simply preventing light from going out from the side of the light guide plate.

Hereinafter, referring to the operation of the present embodiment, when the first letter display unit 12 is to be displayed to the outside, the first light source 16 emits light to the side surface of the first light guide plate 11. The light irradiated on the side surface of the first LGP 11 moves through the interior of the first LGP 11 and is reflected by the first letter display unit 12 printed on the lower portion of the first LGP 11 to form a liquid crystal in a transparent state. The panel 30, the second keyboard display layer 20, and the cover layer 40 penetrate through the outside to allow the first letter display unit 12 to be viewed from the outside.

At this time, the light source on the side of the second light guide plate 21 is turned off so that the second character display unit does not appear, and the second character display unit 22 formed on the bottom surface of the second light guide plate 21 has some transparency. The light indicating the characters of the first character display unit 12 can be transmitted, and there is no problem in displaying the first character display unit 12 to the outside.

In order to display the second character display unit 22 to the outside, the second light source 26 is turned on and irradiated to the second light guide plate 21 side surface. The light irradiated to the side of the second light guide plate 21 moves through the inside of the second light guide plate 21 and is reflected by the second letter display unit 22 printed at the bottom to reflect the second light guide plate 21 and the cover layer 40. By passing through the outside to be emitted to the outside so that the second character display unit 22 can be seen from the outside.

At this time, the liquid crystal panel is in an opaque state, the light source on the side of the first light guide plate 21 is turned off so that the first letter display unit does not appear to the outside.

As described above, according to the present invention, the first letter display unit 12 associated with the first light guide plate 11 and the second letter display unit 22 associated with the second light guide plate 21 are displayed to the outside while having substantially the same brightness. It can be represented without overlapping.

On the other hand, with respect to the same letter or number buttons of the cover layer, an embodiment in which the letters of the first letter display part are formed to the right and the letters of the second letter display part to the left are also formed so as not to overlap. In this case, since the light beam shining upward while indicating the character of the first character display part does not pass the area where the character, etc. of the second character display part is formed, there is almost no scattering problem in this area, so the first character display part is more clearly visible from the outside. Character can be recognized.

The present invention has been described above with reference to some specific embodiments described, but it is apparent to those skilled in the art that various modifications and changes are possible within the technical spirit of the present invention, and such modifications and modifications are within the scope of the appended claims. Belonging is natural.

Claims (4)

A first keyboard display layer comprising a first light guide plate and a first letter display unit coupled to each other;
A liquid crystal panel disposed on the first keyboard display layer and having a transparency depending on whether a voltage is applied to serve as an optical shield;
And a second keyboard display layer on the liquid crystal panel, the second light guide plate and the second letter display unit being coupled to each other. The method of claim 1,
The liquid crystal panel is a keypad device having a superimposed keyboard, characterized in that the liquid crystal panel using a polymer dispersed liquid crystal (PDLC). The method of claim 1,
At least one of the first letter display unit and the second letter display unit is formed integrally with the light guide plate by allowing a character to be directly displayed on the surface of the light guide plate by one of a coating method, a surface treatment method, a surface treatment method and a coating method. Keypad device having a superimposed keyboard. The method of claim 1,
Wherein the first letter display portion is characterized in that the letter or number is displayed on a separate sheet from the first light guide plate and placed on the first light guide plate so that the light from the first light guide plate is transmitted through the sheet to be emitted to the outside Keypad device with superimposed keyboard.

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