KR20020024605A - Method of reducing the number of key switches for input devices - Google Patents

Abstract

PURPOSE: A method for reducing the number of key switches in an input device is provided to recognize all the numbers and special keys with a small number of key switches by allocating a key value to the combination of key signals, without allocating a key switch to each numeric or function key. CONSTITUTION: A CPU in an input device reads by which key operation a key signal is inputted(101). If the read key signal is a single key signal(103), the CPU recognizes a key value allocated to the single key signal from a memory and processes it(105). However, in case that the read key signal is not a single key signal, which means it is a combination of several key signals(107), the CPU checks the location of the combined key signal through a table stored in the memory(109). For example, if the read key signal is a combination of the first key signal and the second key signal and a key value of "2" is allocated to the combination, the CPU recognizes the key value as "2".

Description

Method of reducing the number of key switches for input devices}

The present invention relates to a method for reducing the number of keyswitches of an input device such as a cellular phone, a PDA, a handy transceiver, an electronic calculator, and the like, when two or more keys are simultaneously pressed, a pre-assignment is made for each combination of the keyswitches. The key value is recognized.

Scaling limits for input devices that are becoming increasingly small, depend on the number of physical keybuttons. For example, communication terminals usually require at least 12 key buttons because 10 numeric keys 0-9 are used, and special keys such as * and # are used. If several function keys are added to this, at least 15 to 20 key buttons are required.

Therefore, no matter how small the parts and simplify the circuit, the reduction of the overall product size is limited. And if the key button is made too small with the emphasis on miniaturization of a product, it becomes difficult to press it with a human finger.

In addition, as the number of key buttons increases, the failure rate increases, the assemblability decreases, and the manufacturing cost increases.

It is an object of the present invention to recognize a pre-assigned key value for each combination when two or more keyswitches are operated at the same time without assigning a separate keyswitch for each number or function key to the input device. It provides a way to recognize all numbers and special keys.

1 is a flow chart showing the outline of the key button implementation method according to the present invention

2 is an overview of a communication terminal (mobile phone) equipped with a key button according to the present invention;

3 shows four key switch arrangement circuits located below the numeric key button 20 of FIG.

4 is a table of key signal combinations in a key switch structure arranged as in FIG.

5 is a process flowchart in the case of FIGS. 3 and 4

6 shows two key switch arrangement circuits located below the special key button 30 of FIG.

FIG. 7 is a table of key signal combinations in a key switch structure arranged as in FIG.

8 is a process flowchart in the case of FIGS. 6 and 7

<Description of Drawing Main Parts>

Communication terminal body 10, numeric key button 20, special key button 30, key switch (a, b, c, d, e, f), key signal output terminal (Sa, Sb, Sc, Sd, Se, Sf)

Summary of the Invention

The method of reducing the number of keyswitch according to the present invention is a method performed in an input device composed of a plurality of keyswitches arranged by one keypad.

1) assigning a key value for each single key signal output from the keyswitch,

2) assigning a key value to a combination of key signals output from the keyswitch,

3) reading a key signal generated when a user presses a keypad to operate a key switch, and recognizes a key value assigned thereto when the read key signal is a single key signal,

4) If the user presses the keypad and reads the key signal generated by operating the key switch, the read key signal is a combination of several key signals, and the key value assigned to the combined key signal is recognized.

The key value assignment step for the key signal combination of step 2) may be performed for a combination of two adjacent key switches or a combination of a plurality of non-adjacent key switches in the plurality of arranged key switches.

1 is a flow chart showing the outline of a key button implementation method according to the present invention. The CPU of the input device reads which key is operated to input the key signal [101].

If the read key signal is a single key signal [103], the key value assigned to the key signal is recognized by the memory and processed [105]. For example, a key value "1" is assigned to a first key signal, a key value "3" is assigned to a second key signal, a key value "7" is assigned to a third key signal, and a key value "9" is assigned to a fourth key signal. If so, the CPU finds and recognizes the key value assigned to each single key signal.

If the read key signal is not a single key signal [107], that is, if a plurality of key signals are read in combination, the position of the combined key is determined as to which key combination is the combined key signal [109]. The combination of keys can be found by referring to a table stored in memory.

After determining the positions of the combined keys, the key values assigned to the combinations are recognized as key input signals and processed. For example, if the read key signal is a key signal in which " first key signal + second key signal " is combined and the key value " 2 " has been previously assigned to this combination, the CPU processes "2" as the key value in this case. .

The above process is an outline of a key button implementation method according to the present invention. The concept of the method will be clearly understood in the description of the embodiments described below.

Description of Examples

2 is an overview view of a cellular phone equipped with a key button according to the present invention. Numeric key button 20 and special key button 30 is provided in the main body 10. The numeric key button 20 operates four key switches a, b, c, and d by one keypad. The special key button 30 operates two key switches e and f by one keypad. In this embodiment, the numbers 1 to 9 are input by the operation of the numeric key button 20, and the keys 0, *, and # are input by the operation of the special key button 30.

Under the concept of the present invention described in FIG. 1, a key value is recognized and processed according to which single key switch or combination of key switches of a, b, c, d is pressed. It will be described in detail below.

Fig. 3 briefly shows four key switch arrangement circuits located below the numeric key button 20 in which the method of the present invention is implemented. In FIG. 2, each of the key switches a, b, c, d and e, f is operated by the numeric key button 20 and the special key button 30, and when viewed by the user, the numeric key buttons 20 and Only the special key button 30 is visible.

In Fig. 3, the key switches a, b, c, d are arranged in all directions, one terminal of each key switch is grounded to a common ground, and the other terminal forms the key signal output terminals Sa, Sb, Sc, and Sd. . The resistor connected to each output terminal is a pull-up resistor.

In the key arrangement structure of Fig. 3, the key signal output terminal maintains the " H " level when each key switch is turned off, but falls to the " L " level when the key switch is turned on, but this is an embodiment of the present invention. If only the technical idea of the present invention is used, those skilled in the art will be able to design arbitrarily regardless of the circuit scheme.

FIG. 4 shows a key signal combination table in the key switch structure arranged as shown in FIG. This combination table is designed by the designer in advance and stored in the memory to be used as a reference table. In the table of Fig. 4, if only one key switch a is turned on, the key value " 1 " is assigned to recognize it, " 3 " for the key switch b, " 7 " for the key switch c, It can be seen that " 9 " is assigned to the key switch d.

In the case of the key switch combination, "2" is assigned when the key switch (a) and the key switch (b) are combined, and "4" is assigned when the key switch (a) and the key switch (c) are combined. You can see that it is assigned. However, when the key switch a and the key switch d are combined, as shown in Fig. 2 or Fig. 3, it is difficult to simultaneously turn on the key switches at positions far apart from each other in the diagonal direction, so that no key value is assigned. Similarly, no key value is assigned to the combination of b-c. On the other hand, although not shown in Fig. 4, the key value " 5 " is assigned to be recognized when three or more arbitrary keys are combined.

As a result, in this embodiment, when the keyswitch ab, bd, dc, ca are turned on at the same time, the assigned key value is recognized in each case, and when the keyswitch abd or bdc or dca or abcd are turned on at the same time, the key value of "5" is turned on. Is recognized. Of course, when each key switch is turned on singly, the key value assigned to it is recognized. Therefore, the user presses a point between the key switches a and b of the numeric key button 20 to input "2", and simultaneously turns on the keyswitch a and b, and the numeric key button ( Press the center point of 20) to turn on three or more keyswitches simultaneously.

FIG. 5 shows the process sequence in the case of FIGS. 3 and 4. FIG.

In the state where the CPU is preparing to read the key signal [201], when three or more key switches are turned on at the same time [203], "5" is recognized as the key value [205]. Here, since three or more key switches are turned on at the same time, it is impossible to be strictly speaking. Therefore, it is preferable to give a margin to the time difference at which each key switch is turned on. This is obvious to those skilled in the art.

If three or more keyswitches are not on at the same time [207], check if Sa is "L", if so [209] recognize the assigned key value "1" [211], if Sa is not "L" [ 213] Check if Sb = "L".

If Sb = "L" [215], key value "3" is recognized [217], and if Sb ≠ "L" [219] Sc is checked whether Sc = "L". If Sc = "L" [221], the key value "7" is recognized [223], and if Sc? "L" [225], it is checked whether Sd = "L". If Sd = "L" [227], the key value "9" is recognized [229]. If Sd ≠ "L" [231], it is checked whether Sa and Sb are "L" at the same time (Sa (Sb = "L").

If Sa∧Sb = "L" [233], the key value "2" is recognized [235]. If Sa∧Sb ≠ "L" [237], it is checked whether Sb \ Sd = "L". If Sb∧Sd = "L" [239], the key value "6" is recognized [241]. If Sb \ Sd ≠ "L" [243], it is checked whether Sd \ Sc = "L". If Sd∧Sc = "L" [245], the key value "8" is recognized [247]. If Sd∧Sc ≠ "L" [249], it is checked whether Sc∧Sa = "L". If Sc∧Sa = "L" [251], the key value "4" is recognized [253]. If Sc∧Sa ≠ "L" [255], the process cycle is terminated and waits for the next key signal [257].

FIG. 6 shows two key switch arrangement circuits located below the special key button 30 shown in FIG. In FIG. 2, the key switches e and f are operated by the special key button 30, and only the special key button 30 is visible to the user. In the case of this embodiment, the special key button 30 is configured to output three key signals of "0", "*", and "#".

As in Fig. 3, the key switches e and f are arranged side by side, one terminal of each key switch is grounded to the common ground, and the other terminal forms the key signal output terminals Se and Sf. The resistor connected to each output terminal is a pull-up resistor. In addition, when each key switch is turned off, the corresponding key signal output terminal maintains the " H " level and falls to the " L " level when the key switch is turned on.

FIG. 7 shows a key signal combination table in the key switch structure arranged as shown in FIG. This combination table is designed by the designer in advance and stored in the memory to be used as a reference table. In the table of Fig. 7, it can be seen that if only one key switch e is on, the key value " * " is assigned to be recognized, and "# " is assigned to the key switch f. In the case of the key switch combination, it can be seen that " 0 " is assigned when the key switch e and the key switch f are combined.

As a result, "*" and "#" key values are recognized when the keyswitch e and f are turned on singly, respectively, but when ef is turned on at the same time (i.e., when the user presses an intermediate point of the special key button 30). ), The assigned key value "0" is recognized.

FIG. 8 shows the process sequence in the case of FIGS. 6 and 7. FIG.

When the CPU is preparing to read the key signal [301], it checks whether Se is "L", and if so [303] recognizes the assigned key value "*" [305], and Se is not "L". [307] Check whether Sf = "L".

If Sf = "L" [309], the key value "#" is recognized [311], and if Sf ≠ "L" [313], it is checked whether Se and Sf are "L" at the same time (Se # Sf = "L").

If Se∧Sf = "L" [315], the key value "0" is recognized [317]. If Se∧Sf ≠ "L" [319], the process cycle ends and waits for the next key signal [321].

In the above, embodiments of the key switch reduction method according to the present invention have been described with reference to the drawings. However, the technical idea of the present invention is not limited to the embodiment according to the drawings, but equivalent to the technical scope that the key switch claimed in the claims recognizes the assigned key value by judging the on combination at the same time. equivalent) covers all cases involved.

For example, in the present embodiment, the implementation method was described only for the numeric keys and the special keys, but it is obvious to those skilled in the art that the technical idea of the present invention can be applied to the input method of the character keys (Korean alphabet or English alphabet) as it is. .

In addition, the technical idea of the present invention is not limited to the mobile phone shown in the embodiment, and is applicable to all input devices for inputting numbers or letters such as PDAs, set-top boxes, handy transceivers, wristwatches, and electronic calculators.

According to the present invention, the number of key buttons is basically reduced as compared to the conventional. As a result, product reduction is easy, manufacturing cost is reduced, and it is convenient to use and number input is possible without seeing. In other words, since the size of the keypad that a person must press is wide, it is easy to press even if the size of the product is reduced. In addition, the assemblability is improved and the failure rate is reduced since the keyswitch is reduced.

Claims (9)

A method of reducing the number of keyswitches formed in an input device composed of a plurality of keyswitches arranged by one keypad, 1) assigning a key value for each single key signal output from the keyswitch, 2) assigning a key value to a combination of key signals output from the keyswitch, 3) reading a key signal generated when a user presses a keypad to operate a key switch, and recognizes a key value assigned thereto when the read key signal is a single key signal, 4) reading the key signal generated when the user presses the keypad to operate the key switch, and if the read key signal is a combination of several key signals, recognizing a key value assigned to the combined key signal. How to reduce the number of keyswitch of the device. The method according to claim 1, wherein the key value assignment step for the key signal combination of step 2) is performed for a combination of two adjacent key switches in a plurality of arranged key switches. The method according to claim 1, wherein the key value assignment step for the key signal combination of step 2) is performed for a combination of a plurality of non-adjacent key switches in the arranged plurality of key switches. The method of reducing the number of keyswitch of an input device according to any one of claims 1 to 3, wherein the key value is a numeric key. The method according to any one of claims 1 to 3, wherein the key value is a character key. Numeric key button 20 is installed in the input device, the numeric key button 20 is operated by four key switches (a, b, c, d) by one keypad, the numeric key button 20 In the input device which numbers 1-9 are input by operation, When only one key switch a is turned on, the key value "1" is assigned to be recognized. The key switch b is "3", the key switch c is "7", and the key switch d is " 9 "is assigned, the key value" 2 "is assigned when the key switch a and the key switch b are combined, and the key value" 4 "when the key switch a and the key switch c are combined. Is assigned, the key value "6" is assigned when the key switch b and the key switch d are combined, and the key value "8" is assigned when the key switch c and the key switch d are combined. And an "5" is assigned when three or more arbitrary keys are combined. A method of reducing the number of keyswitches formed in an input device configured as claimed in claim 6, In a state where the CPU is preparing to read the key signal [201], when three or more keyswitches are turned on at the same time [203], recognizing "5" as the key value; If three or more keyswitches are not on at the same time [207], check whether Sa is on, if so [209] recognize the assigned key value "1" [211], if Sa is not on [213] Checking if it is on, If Sb is on [215] recognizes key value " 3 " [217] and if Sb is not on [219] checking if Sc is on, If Sc is on [221] recognizes key value "7" [223] and if Sc is not on [225] checking if Sd is on, If Sd is on [227] recognizing key value "9" [229] and if Sd is not on [231] checking whether Sa and Sb are on at the same time, If Sa∧Sb is on [233] recognizing key value "2" [235], if Sa∧Sb is not on [237] checking whether Sb∧Sd is on, If Sb∧Sd is on [239], key value "6" is recognized [241], and if Sb'Sd is not on [243] checking whether Sd'Sc is on, If Sd \ Sc is on [245], key value "8" is recognized [247], if Sd \ Sc is not on [249] checking whether Sc \ Sa is on, An input device consisting of recognizing the key value "4" if Sc \ Sa is on [253] and [253] if Sc \ Sa is not on [255] and ending the process cycle and waiting for the next key signal in a waiting state; How to reduce the number of keyswitch The special device button 30 is installed in the input device, and the special key button 30 is operated by two key switches (e, f) by one keypad, and is operated by the operation of the special key button 30. In the input device, the key of *, #, is input, When only one key switch e is turned on, the key value "*" is assigned to be recognized, "#" is assigned to the key switch f, and "0" when the key switch e and the key switch f are combined. Input device which is assigned. A method of reducing the number of keyswitches formed in an input device constituted as claimed in claim 8, When the CPU is ready to read the key signal [301], it checks whether Se is on, and if so [303] recognizes the assigned key value "*" [305], and if Se is not on [307]. Checking whether Sf is on, If Sf is on [309], it recognizes the key value "#" [311], and if Sf is not on [313] checking whether Se and Sf are on at the same time (SefSf is on), If Se∧Sf is on [315], the key value "0" is recognized [317]. If Se∧Sf is not on [319], the process cycle ends and waits for the next key signal in the waiting state [321]. To reduce the number of keyswitch of the input device.