KR100628071B1 - Key pad and mobile terminal - Google Patents

Abstract

The present invention includes a first resistor connected between the power supply voltage and the output terminal; A first voltage divider connected between the output terminal and the ground to perform a first voltage divider with respect to the power supply voltage; A second voltage divider connected between the output terminal and the ground and configured to divide the first divided voltage into a second voltage and output the divided voltage to the output terminal; A keypad device and a mobile communication terminal comprising a switching unit for connecting the first voltage divider and the second voltage divider in series or in parallel according to whether or not a predetermined key is input. It has the effect of preventing errors.

Mobile terminal, keypad, key input

Description

Keypad Device and Mobile Terminal {Key Pad and Mobile Terminal}

1 is a circuit diagram showing a keypad matrix of a conventional mobile communication terminal.

2 is a configuration diagram of an embodiment of a mobile communication terminal according to the present invention.

3 is a diagram illustrating an embodiment of a keypad according to the present invention.

<Description of the symbols for the main parts of the drawings>

210: keypad 220: digital conversion means

230: control means 240: display unit

The present invention relates to a keypad of a mobile communication terminal, and more particularly, to a keypad device and a mobile communication terminal that prevents a key recognition error generated when a plurality of keys are simultaneously input.

1 is a circuit diagram showing a keypad matrix of a conventional mobile communication terminal.

Referring to FIG. 1, a, b, c, d, e, and f are output terminals.

Also, g, h, i and j are input terminals.

Switches SW1... And SW21 are disposed at intersections of the output terminals and the input terminals.

Hereinafter, a key recognition operation process of the keypad matrix of the conventional mobile communication terminal will be described.

Key recognition of the keypad outputs only one of the a, b, c, d, e, and f terminals, which are output terminals, as high, and the other output terminals as low.

At this time, if any one of the input terminals g, h, i, and j terminals are input high, the key is pressed, and the key sensing is performed by a combination of the output terminals and the input terminals being high. do.

1. When the user presses one of the keys on the keypad.

When the user presses the first key on the keypad, the switch SW5 assigned to the first key is turned on so that the output terminal b and the input terminal g of the first key change to a high state and the remaining output terminals And the input terminals are both changed to the low state.

Accordingly, the controller (not shown) of the mobile communication terminal recognizes that the first key is input by the combination of the output terminal b and the input terminal g, and does not recognize that the keys other than the first key are input. .

2. When the user presses an additional 3 key while pressing the 1 key.

When the user presses the third key while the first key is pressed, the switch SW7 assigned to the third key is turned on so that the output terminal b and the input terminal i of the third key are in a high state. Changes to.

Accordingly, the controller (not shown) of the mobile communication terminal recognizes that the first and third keys are input by the combination of the output terminal b and the input terminal g and the combination of the output terminal b and the input terminal i. However, it does not recognize that the keys other than the 1 key and the 3 key are input.

3. When the user presses the additional key 9 while pressing the key 1 and 3.

When the user presses the key 9 while the key 1 and key 3 are pressed, the switch SW15 assigned to the key 9 is turned on, so that the output terminal d and the input terminal i of the key 9 are high. It changes to (High) state.

Therefore, the controller (not shown) of the mobile communication terminal includes a combination of the output terminal b and the input terminal g, a combination of the output terminal b and the input terminal i, a combination of the output terminal d and the input terminal i, The combination of the output terminal d and the input terminal g recognizes that the key 1, the key 3, the key 9 and the key 7 are input.

However, the control unit incorrectly recognizes the seventh key input by the combination of the output terminal and the input terminal even though the seventh key is not input by the user.

In conclusion, the conventional method of recognizing the key input in the keypad matrix structure recognizes the key input by the combination of the output terminal and the input terminal. There is a problem to recognize.

An object of the present invention is to provide a keypad device and a mobile communication terminal that prevents a key recognition error generated when a plurality of keys of a keypad are simultaneously input.

A keypad device according to the present invention for achieving the above object comprises a first resistor connected between a power supply voltage and an output terminal; A first voltage divider connected between the output terminal and the ground to perform a first voltage divider with respect to the power supply voltage; A second voltage divider connected between the output terminal and the ground and configured to divide the first divided voltage into a second voltage and output the divided voltage to the output terminal; It includes a switching unit for connecting the first voltage divider and the second voltage divider in series or in parallel depending on whether a predetermined key input.

In addition, the child communication terminal according to the present invention includes a keypad for generating a voltage value according to a predetermined key input of a plurality of keys and a voltage value according to an additional key input during the key input; Digital conversion means for converting the generated voltage value into a digital signal and outputting the digital signal; And control means for performing a control operation corresponding to the converted digital signal.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram of an embodiment of a mobile communication terminal according to the present invention.

Referring to FIG. 2, the keypad 210 includes a plurality of numeric keys and function keys, and outputs key signals for the keys to the control means 230.

The keypad 210 generates a voltage value according to a predetermined key input among the plurality of keys and a voltage value according to an additional key input during the key input, according to an embodiment of the present invention. Will print

Hereinafter, the keypad 210 according to an embodiment of the present invention will be described in detail.

3 is a diagram illustrating an embodiment of a keypad according to the present invention.

Referring to FIG. 3, the keypad 210 includes a first resistor R1, a first voltage divider 211, a second voltage divider 212, and a switch 213.

The first resistor R1 is connected between the power supply voltage (+ 3.0V) and the digital conversion means 220.

The first voltage dividing unit 211 is connected between the digital conversion unit 220 and ground, and performs a first voltage division on the power supply voltage (+ 3.0V).

Preferably, the first voltage divider 211 includes a plurality of resistors R ₁₁ , R ₁₂ ,..., R _k , and the plurality of resistors R ₁₁ , R _{12 ,.} Each is connected in series.

The second voltage dividing unit 212 is connected between the digital conversion unit 220 and the ground, and further divides the voltage divided first by the first voltage dividing unit 211 to the digital conversion unit 220. Will print

Preferably, the second voltage divider 212 includes a plurality of resistors R ₂₁ , R ₂₂ ,..., And R _m , and the plurality of resistors R ₂₁ , R _{22 ,.} Each is connected in series.

A switching unit (213) comprises a plurality of switches (SW _0, SW _1, ..., SW _n), the plurality of switches in the (SW _0, SW _1, ..., SW _n) is a keypad (210) Are assigned to keys, respectively.

In addition, the switches SW ₀ , SW ₁ ,..., SW _n are connected to nodes of resistors provided in the first voltage divider 211 and the second voltage divider 212, respectively.

Hereinafter, a process of generating the first divided voltage value according to one key input of the user will be described in detail.

When a predetermined one of the plurality of keys of the keypad 210 is input by a user, a switch corresponding to the key is turned on to connect the first voltage divider 211 and the second voltage divider 212 in series.

The first voltage dividing unit 211 divides the power supply voltage by Equation 1 below.

[Equation 1]

Division voltage = power supply voltage × resistance ratio

The first voltage dividing unit 211 outputs the divided voltage value to the digital converter 220.

Hereinafter, the voltage value generation process according to the one key input will be described in detail.

It is assumed that the resistance of the first resistor R ₁ is 10 kΩ, the resistance of the resistors of the first voltage divider 211 is 10 kΩ, and the resistance of the resistors of the second voltage divider 212 is 20 kΩ.

1. When the user presses the 0 key.

When a number 0 key of the plurality of keys of the keypad 210 is input by the user, the switch SW ₀ corresponding to the key is turned on and generates a voltage value by Equation 1 above.

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3V × [{10㏀ (R ₁₁ ) + 10㏀ (R ₁₂ ) + 10㏀ (R ₁₃ ) + 10㏀ (R ₁₄ ) + 10㏀ (R ₁₅ )} / {10㏀ (R ₁ ) + 10㏀ (R ₁₁ ) + 10㏀ (R ₁₂ ) + 10㏀ (R ₁₃ ) + 10㏀ (R ₁₄ ) + 10㏀ (R ₁₅ )}]

Voltage divider = 3V × 50㏀ / 60㏀ = 2.5V

2. When the user presses the 1 key.

When the first key of the plurality of keys of the keypad 210 is input by the user, the switch SW ₁ corresponding to the key is turned on and generates a voltage value by Equation 1 above.

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3V × [{20㏀ (R ₂₁ ) + 10㏀ (R ₁₂ ) + 10㏀ (R ₁₃ ) + 10㏀ (R ₁₄ ) + 10㏀ (R ₁₅ )} / {10㏀ (R ₁ ) + 20㏀ (R ₂₁ ) + 10㏀ (R ₁₂ ) + 10㏀ (R ₁₃ ) + 10㏀ (R ₁₄ ) + 10㏀ (R ₁₅ )}]

Voltage divider = 3V × 60㏀ / 70㏀ = 2.57V

3. The user presses the 2 key.

When a key 2 of the plurality of keys of the keypad 210 is input by the user, the switch SW ₂ corresponding to the key is turned on and generates a voltage value by Equation 1 above.

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3V × [{20㏀ (R ₂₁ ) + 20㏀ (R ₂₂ ) + 10㏀ (R ₁₃ ) + 10㏀ (R ₁₄ ) + 10㏀ (R ₁₅ )} / {10㏀ (R ₁ ) + 20㏀ (R ₂₁ ) + 20㏀ (R ₂₂ ) + 10㏀ (R ₁₃ ) + 10) (R ₁₄ ) + 10㏀ (R ₁₅ )}]

Voltage divider = 3V × 70㏀ / 80㏀ = 2.625V

As described above, the keypad 210 generates different voltage values according to one key input of the user and outputs them to the digital converting means 220.

Hereinafter, a process of generating a second divided voltage value according to a plurality of key inputs of a user according to an embodiment of the present invention will be described in detail.

Preferably, the plurality of key inputs means that a plurality of keys of the keypad 210 are simultaneously input or additionally a plurality of keys are input while the one key is input.

When a plurality of keys of the keypad 210 are simultaneously input by a user, switches corresponding to the keys are turned on to connect the first voltage dividing unit 211 and the second voltage dividing unit 212 in parallel.

The first voltage dividing unit 211 performs a first voltage dividing by the above equation 1 with respect to the power supply voltage.

The second voltage dividing unit 212 performs second voltage dividing again with respect to the voltage divided first by the first voltage dividing unit 211.

The second voltage divider 212 outputs the second voltage divided by the digital converter 220.

Hereinafter, a process of generating voltage values according to the plurality of key inputs will be described in more detail, for example.

It is assumed that the resistance of the first resistor R ₁ is 10 kΩ, the resistance of the resistors of the first voltage divider 211 is 10 kΩ, and the resistance of the resistors of the second voltage divider 212 is 20 kΩ.

1. When the user presses the 1 key while pressing the 0 key.

If the first key is additionally input while the zero key of the plurality of keys of the keypad 210 is input by the user, the switches SW ₀ and SW ₁ corresponding to the keys are turned on and the equation 1 is applied. Generate the voltage value.

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3V × [{200㏀ (R ₁₁ × R ₂₁ ) / 30㏀ (R ₁₁ + R ₂₁ ) + 40㏀ (R ₁₂ + R ₁₃ + R ₁₄ + R ₁₅ )} / {10㏀ (R ₁ ) + 200 ㏀ (R ₁₁ × R ₂₁ ) / 30 ㏀ (R ₁₁ + R ₂₁ ) + 40 ㏀ (R ₁₂ + R ₁₃ + R ₁₄ + R ₁₅ )}]

Voltage divider = 3V × 46.7㏀ / 56.7㏀ = 2.47V

2. When the user presses the 2 key while pressing the 0 key.

When the second key is additionally input while the zero key of the plurality of keys of the keypad 210 is input by the user, the switches SW ₀ and SW ₂ corresponding to the keys are turned on and are expressed by Equation 1 below. Generate the voltage value.

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3 V × [( ₂₀ ㏀ (R ₁₁ + R ₁₂ ) × 40 ㏀ (R ₂₁ + R ₂₂ ) / 60 ㏀ (R ₁₁ + R ₁₂ + R ₂₁ + R ₂₂ ) + 30 ㏀ (R ₁₃ + R ₁₄ + R ₁₅ )} / (10 ㏀ (R ₁ ) + ₂₀ ㏀ (R ₁₁ + R ₁₂ ) × 40 ㏀ (R ₂₁ + R ₂₂ ) / 60 ㏀ (R ₁₁ + R ₁₂ + R ₂₁ + R ₂₂ ) + 30㏀ (R ₁₃ + R ₁₄ + R ₁₅ )}]

Voltage divider = 3V × 43.3㏀ / 53.3㏀ = 2.43V

3. The user presses the 4 key while holding down the 0 and 2 keys.

If key 4 is additionally input while key 0 and key 2 of the plurality of keys of the keypad 210 are input by the user, switches corresponding to the keys SW ₀ , SW ₂ , and SW ₄ are turned on. The voltage value is generated by the above equation (1).

Division voltage = power supply voltage × resistance ratio

Voltage divider = 3 V × [( ₂₀ ㏀ (R ₁₁ + R ₁₂ ) × 40 ㏀ (R ₂₁ + R ₂₂ ) / 60 ㏀ (R ₁₁ + R ₁₂ + R ₂₁ + R ₂₂ ) + ₂₀ ㏀ (R ₁₃ + R ₁₄ ) × 40 ㏀ (R ₂₃ + R ₂₄ ) / 60 ㏀ (R ₁₃ + R ₁₄ + R ₂₃ + R ₂₄ ) + 10 ㏀ (R ₁₅ )} / {10 ㏀ (R ₁ ) + 20 ㏀ (R ₁₁ + R ₁₂ ) × 40 ㏀ (R ₂₁ + R ₂₂ ) / 60 ㏀ (R ₁₁ + R ₁₂ + R ₂₁ + R ₂₂ ) + ₂₀ ㏀ (R ₁₃ + R ₁₄ ) × 40 ㏀ (R ₂₃ + R ₂₄ ) / 60㏀ (R ₁₃ + R ₁₄ + R ₂₃ + R ₂₄ ) + 10㏀ (R ₁₅ )}]

Voltage divider = 3 V × 36.67 ㏀ / 46.67 2. = 2.357 V

As in the voltage value calculation process, the keypad 210 generates a voltage value according to one key input and a voltage value according to a plurality of key inputs differently, and outputs them to the digital converting means 220.

The digital conversion means 220 converts the voltage value generated by the keypad 210 into a digital signal so that the control means 230 can recognize it.

Preferably, the digital conversion means 220 is an analog to digital converter (AD converter).

The control means 230 controls the overall operation of the mobile communication terminal, and outputs a key signal corresponding to the converted digital signal to the display means 240.

The display means 240 receives and displays the display data of the key signal input from the keypad 210 according to the control signal of the control means 240.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The keypad device and the mobile communication terminal according to the present invention have an effect of preventing a key recognition error generated when a plurality of keys of the keypad are simultaneously input.

Claims (21)

A first resistor connected between the power supply voltage and the output terminal; A first voltage divider connected between the output terminal and the ground to perform a first voltage divider with respect to the power supply voltage; A second voltage divider connected between the output terminal and the ground to divide the first divided voltage into a second voltage to output the output voltage to the output terminal; And And a switching unit for connecting the first voltage divider and the second voltage divider in series or in parallel according to a predetermined key input. The method of claim 1, The first voltage dividing unit includes a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 1, The second voltage dividing unit includes a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 1, The switch unit, the keypad device characterized in that the switch is assigned to a plurality of keys, respectively. The method of claim 4, wherein The plurality of switches, the keypad device, characterized in that connected to each node of the resistor provided in the first and second voltage divider. The method of claim 5, The first voltage dividing unit includes a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 5, The second voltage dividing unit includes a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 1, The switching unit, when a predetermined key is input, the keypad device, characterized in that for connecting the first voltage divider and the second voltage divider in series through the switch corresponding to the key. The method of claim 1, The switching unit, when a plurality of keys are input at the same time, through the switches corresponding to the keys by connecting the first voltage divider and the second voltage divider unit in parallel. The method of claim 8, The switching unit, when at least one key is input during the key input, the keypad device, characterized in that for connecting the first voltage divider and the second voltage divider in parallel through the switches corresponding to the additional input key. The method of claim 1, The keypad device is a keypad device, characterized in that provided in the mobile communication terminal. A keypad for differently generating a voltage value according to a predetermined key input among the plurality of keys and a voltage value according to an additional key input during the key input; Digital conversion means for converting the generated voltage value into a digital signal and outputting the digital signal; And And control means for performing a control operation corresponding to the converted digital signal. The method of claim 1, wherein the keypad, A first resistor connected between a power supply voltage and the digital converter; A first voltage divider connected between the digital converter and ground to perform a first voltage divider with respect to the power supply voltage; A second voltage divider connected between the digital converter and a ground to divide the first divided voltage into a second voltage and output the second divided voltage to the digital converter; And And a switching unit for connecting the first voltage divider and the second voltage divider in series or in parallel according to whether the key is pressed. The method of claim 13, The first voltage divider is composed of a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 13, The second voltage divider is composed of a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 13, The switching unit is composed of a plurality of switches, characterized in that each assigned to the plurality of keys. The method of claim 16, And the plurality of switches are connected to nodes of resistors provided in the first and second voltage dividers, respectively. The method of claim 17, The first voltage divider is composed of a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 17, The second voltage divider is composed of a plurality of resistors, and the plurality of resistors are each connected in series. The method of claim 13, The switching unit, if a predetermined key is input, the mobile communication terminal, characterized in that for connecting the first voltage divider and the second voltage divider in series through the switch corresponding to the key. The method of claim 13, The switching unit, when a plurality of keys are input at the same time, the mobile communication terminal, characterized in that for connecting the first voltage divider and the second voltage divider in parallel through the switches corresponding to the keys.

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