CN201917871U - Input device that eliminates ghost keys - Google Patents

Abstract

An input device capable of eliminating ghost keys, comprising: the switch module comprises a plurality of driving wires, a plurality of sensing wires and a plurality of switch units, wherein the driving wires, the sensing wires and the switch units respectively receive a plurality of driving signals; a comparator including a first input terminal, a second input terminal for receiving a reference signal, and an output terminal for outputting a comparison signal; a switching unit, controlled by a set of control signals, for electrically connecting at least one sensing line to the first input terminal of the comparator; and a processing module for setting at least a portion of the drive signal, the reference signal, and the set of control signals such that the comparison signal indicates whether at least one of the switches is on, or whether one of the switches is on.

Description

Input device that eliminates ghost keys

technical field

The utility model relates to an input device, in particular to an input device capable of eliminating ghost keys.

Background technique

Referring to Fig. 1, a kind of existing keyboard device is shown among them. The switch module 1 includes a plurality of driving lines 111 - 114 , a plurality of sensing lines 121 - 124 and a plurality of switch units 13 . Each switch unit 13 includes a switch 131 electrically connected between a corresponding one of the driving lines 111 - 114 and a corresponding one of the sensing lines 121 - 124 . For example, when the switch 131 electrically connected to the first driving line 111 and the first sensing line 121, the switch 131 electrically connected to the first driving line 111 and the third sensing line 123 and electrically connected to the third When the switches 131 of the first driving line 113 and the first sensing line 121 are turned on at the same time, except that these three switches 131 will be judged as being turned on, the switches electrically connected to the third driving line 113 and the third sensing line 123 The switch 131 will also be judged to be turned on, which is the so-called "ghost key". For details, refer to US Patent No. 5,386,584.

Referring to Fig. 2, a kind of existing keyboard device that can eliminate ghost key is different from above-mentioned keyboard device in that: each switch unit 13' also includes a diode 132 connected in series with switch 131. For details, refer to US Patent No. 5,386,584. However, this will increase the cost of the keyboard device, and the switch module 1 cannot be realized by printing on a flexible board.

Referring to Fig. 3, US Patent No. 4633228 discloses another existing keyboard device capable of eliminating ghost keys, and its switch module 2 includes a plurality of drive lines 211-214, a plurality of induction lines 221-224 and a plurality of switch units twenty three. Each switch unit 23 includes a switch 231 and a resistor 232 connected in series between a corresponding one of the driving lines 211 - 214 and a corresponding one of the sensing lines 221 - 224 . Each sensing line 221 - 224 is electrically connected to a supply voltage source via a resistor 3 . This keyboard device uses the voltage level generated by the resistance 232 and the resistance 3 in series with the resistor 232 to divide the voltage as the basis for judging whether a selected switch 231 in the switch 231 is turned on, but this keyboard device has the following disadvantages: (1) For the selected switch 231, when there are more switches 231 that are turned on, the series-parallel equivalent effect of the resistor 232 and the resistor 3 will cause misjudgment easily, especially when the resistance values of the resistor 232 and the resistor 3 When the ratio is smaller, it is more likely to occur; (2) only one switch 231 can be judged at a time, so the total time for judging the respective states of all switches 231 is longer; (3) the precise resistance value of resistor 232 and resistor 3 and (4) each sensing line 221-224 needs to cooperate with a comparator (not shown), so when the number of sensing lines 221-224 increases, the number of comparators must also increase accordingly.

Utility model content

The purpose of the utility model is to provide an input device capable of eliminating ghost keys, which can solve the above-mentioned problems related to the prior art.

The input device capable of eliminating ghost keys of the utility model comprises a switch module, a comparator, a switching unit, a bias resistor and a processing module.

The switch module includes a plurality of drive lines, a plurality of induction lines and a plurality of switch units. Each switch unit includes a switch and a resistor connected in series between a corresponding one of the driving lines and a corresponding one of the sensing lines. Each switch toggles between conduction and non-conduction.

The comparator includes a first input terminal, a second input terminal receiving a reference signal, and an output terminal outputting a comparison signal for comparing the signal received by the first input terminal with the reference signal, so as to get the comparison signal.

The switching unit is electrically connected to the sensing line and the first input terminal of the comparator, and is controlled by a set of control signals to switch, and at least one of the sensing lines is electrically connected to the first input of the comparator. end.

The bias resistor has a first terminal electrically connected to the first input terminal of the comparator, and a second terminal receiving a first voltage level.

The processing module is electrically connected to the driving line, the comparator and the switching unit, and is used to output a plurality of driving signals to the driving line, output the reference signal to the second input terminal of the comparator, and output the The group control signal is sent to the switching unit, and the comparison signal is received from the output terminal of the comparator.

The processing module sets at least a part of the driving signal, the reference signal and the set of control signals so that the comparison signal indicates whether at least one of the switches of the switching unit is turned on.

The processing module also sets at least a part of the drive signal, the reference signal and the set of control signals when the comparison signal indicates that at least one of the switches of the switch unit is turned on, so that the comparison signal indicates Whether at least one switch of the switch unit electrically connected to a selected one of the sensing lines is turned on.

The processing module also sets the driving signal, the reference signal and the set of control signals when the comparison signal indicates that at least one of the switches of the switching unit electrically connected to the selected sensing line is turned on. At least a part, so that the comparison signal indicates whether the switch of the switch unit electrically connected to the selected sensing line and a selected driving line of the driving lines is turned on.

In the input device capable of eliminating ghost keys described in the present utility model, the processing module sets the drive signals to a second voltage level higher than the first voltage level, and sets the reference signal to an intermediate voltage level. a third voltage level between the first voltage level and the second voltage level, and setting the set of control signals so that the switching unit electrically connects the sensing lines to the first input of the comparator terminal, so that the comparison signal indicates whether at least one of the switches of the switch unit is turned on; the processing module sets the reference when the comparison signal indicates that at least one of the switches of the switch unit is turned on The signal is a fourth voltage level between the first voltage level and the second voltage level, and the set of control signals is set so that the switching unit electrically connects the selected sensing line to the comparator the first input terminal of the switch unit, and make the switching unit allow the remaining sensing lines to receive the first voltage level, so that the comparison signal indicates whether at least one of the switches of the switching unit electrically connected to the selected sensing line when the comparison signal indicates that at least one of the switches of the switching unit electrically connected to the selected sensing line is turned on, the processing module sets the drive signal output to the selected drive line as the second voltage level, and set the remaining drive signals to the first voltage level or a high impedance state, so that the comparison signal indicates the switching unit electrically connected to the selected sense line and the selected drive line whether the switch is turned on.

In the input device capable of eliminating ghost keys described in the utility model, the processing module includes: a storage for storing the state of the switch of the switch unit; and a processing unit electrically connected to the storage for outputting the drive signal, the reference signal, and the group of control signals, and receive the comparison signal; the processing unit sets the states stored in the memory as a non-conducting state, and sets the drive signal, the reference signal and the set of control signals, and when the comparison signal indicates that the switch of the switch unit electrically connected to the selected sensing line and the selected drive line is turned on, the switch of the switch unit stored in the memory is set state is a conduction state.

In the input device capable of eliminating ghost keys described in the utility model, the processing unit includes: a processor for outputting the driving signal, a reference current and the group of control signals, and receiving the comparison signal; and a switching resistor , electrically connected to the processor, for converting the reference current into the reference signal; the processor sets the states stored in the memory as the non-conducting state, and sets the drive signal, The reference current and the set of control signals, and when the comparison signal indicates that the switch of the switch unit electrically connected to the selected sensing line and the selected drive line is turned on, the switch unit stored in the memory is set. The state of the switch is the on state.

In the input device capable of eliminating ghost keys described in the utility model, the switching unit includes a plurality of double-cut switches, each double-cut switch includes a first end electrically connected to a corresponding one of the induction lines, and a a second terminal electrically connected to the first input terminal of the comparator, and a third terminal receiving the first voltage level, and the double-cut switch is used to make the first terminal and the second terminal connect to each other according to the set of control signals Conduction between the two terminals or between the first terminal and the third terminal.

The beneficial effects of the utility model are: (1) the switch module does not need to use a diode, which can save costs, and can also be realized by printing on a soft board; (2) the series and parallel connection of the resistors is relatively simple, so The situation of misjudgment is not easy to occur; (3) the processing module can judge whether there is at least one conduction in all or part of the switch at one time, and omit further judgment when it is judged that there is no switch conduction, so it is used for The total time for judging the respective states of the switches is relatively short; (4) the accuracy of the resistance of the resistors is relatively low; and (5) only one comparator is required.

Description of drawings

Fig. 1 is a schematic diagram of a circuit, illustrating a kind of existing keyboard device;

Fig. 2 is a schematic circuit diagram, illustrating a kind of existing keyboard device that can eliminate ghost keys;

Fig. 3 is a schematic circuit diagram illustrating another existing keyboard device capable of eliminating ghost keys;

FIG. 4 is a schematic circuit diagram illustrating a preferred embodiment of an input device capable of eliminating ghost keys according to the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

Referring to FIG. 4 , a preferred embodiment of the input device capable of eliminating ghost keys of the present invention includes a switch module 4 , a comparator 5 , a switching unit 6 , a bias resistor 7 and a processing module 8 .

The switch module 4 includes a plurality of driving lines 41 , a plurality of sensing lines 42 and a plurality of switching units 43 . Each switch unit 43 includes a switch 431 and a resistor 432 connected in series between a corresponding one of the driving lines 41 and a corresponding one of the sensing lines 42 . Each switch 431 is switched between conduction and non-conduction.

The comparator 5 includes a first input terminal, a second input terminal receiving a reference signal and an output terminal outputting a comparison signal, for comparing the signal received by the first input terminal and the reference signal to obtain a comparison Signal. In this embodiment, the first input terminal is a non-inverting input terminal, and the second input terminal is an inverting input terminal.

The switching unit 6 is electrically connected to the sensing line 42 and the first input end of the comparator 5 , is controlled by a set of control signals to switch, and at least one of the sensing lines 42 is electrically connected to the first input end of the comparator 5 . In this example, the switching unit 6 includes a plurality of double-cut switches 61 . Each double-cut switch 61 includes a first end electrically connected to a corresponding one of the sensing lines 42, a second end electrically connected to the first input end of the comparator 5 and a first end receiving a first voltage level ( For example, the third end of the ground voltage level) is used for conducting the first end and the second end or between the first end and the third end according to the set of control signals.

The bias resistor 7 has a first end electrically connected to the first input end of the comparator 5 and a second end receiving the first voltage level, for weakly biasing the voltage level of the first input end of the comparator 5 to the first voltage level, that is to say, if the switching unit 6 outputs a voltage level to the first input terminal of the comparator 5, the voltage level of the first input terminal of the comparator 5 will be substantially equal to that of the switching unit 6. The output voltage level is not the first voltage level, otherwise, the voltage level of the first input terminal of the comparator 5 will be substantially equal to the first voltage level.

The processing module 8 includes a storage 81 and a processing unit 82 . The storage 81 stores the state of the switch 431 of the switch unit 43 . The processing unit 82 is electrically connected to the driving line 41, the comparator 5, the switching unit 6 and the storage 81, and is used to output a plurality of driving signals to the driving line 41, output a reference signal to the second input end of the comparator 5, and output the The group control signal is sent to the switching unit 6, and the comparison signal is received from the output terminal of the comparator 5.

The processing unit 82 sets the state stored in the memory 81 to be a non-conductive state, and sets the drive signal to a second voltage level (such as a power supply voltage level) higher than the first voltage level, and Set the reference signal to a third voltage level between the first voltage level and the second voltage level, and set the set of control signals so that the switching unit 6 electrically connects the sensing lines 42 to the comparator 5 so that the comparison signal indicates whether at least one of the switches 431 of the switch unit 43 is turned on. When the voltage level of the first input terminal of the comparator 5 is substantially greater than the third voltage level, the comparison signal is pulled to the second voltage level substantially to indicate that at least one of the switches 431 of the switch unit 43 is turned on, Otherwise, the comparison signal is substantially pulled to the first voltage level to indicate that none of the switches 431 of the switch unit 43 is turned on.

In this embodiment, the third voltage level is substantially equal to 0.9 times the second voltage level. It should be noted that when none of the switches 431 of the switch unit 43 is turned on, the voltage level of the first input terminal of the comparator 5 will be biased to the first voltage level by the bias resistor 7 substantially, and When at least one of the switches 431 of the switch unit 43 is turned on, the voltage level of the first input terminal of the comparator 5 will be substantially biased to the second voltage level by the switch module 4, therefore, theoretically, the third As long as the voltage level is between the first voltage level and the second voltage level, the purpose of judgment can be achieved, but in order to avoid noise interference from causing judgment errors, preferably, the distance between the third voltage level and the second voltage level The difference is substantially greater than or equal to a preset margin.

The processing unit 82 also sets the reference signal to a fourth voltage level between the first voltage level and the second voltage level when the comparison signal indicates that at least one of the switches 431 of the switch unit 43 is turned on, And set the group of control signals so that the switching unit 6 electrically connects a selected sensing line 42 in the sensing lines 42 to the first input end of the comparator 5, and makes the switching unit 6 allow the remaining sensing lines 42 to receive the first input. voltage level, so that the comparison signal indicates whether at least one of the switches 431 of the switch unit 43 electrically connected to the selected sensing line 42 is turned on. When the voltage level of the first input terminal of the comparator 5 is substantially greater than the fourth voltage level, the comparison signal is pulled to the second voltage level substantially to indicate the switch of the switch unit 43 electrically connected to the selected sense line 42 At least one of the switches 431 is turned on, otherwise, the comparison signal is substantially pulled to the first voltage level to indicate that none of the switches 431 of the switch unit 43 electrically connected to the selected sensing line 42 is turned on.

In this embodiment, the fourth voltage level is substantially equal to 1/(2+2n) times the second voltage level, where n is the number of driving lines 41 . It should be noted that when none of the switches 431 of the switch unit 43 electrically connected to the selected sensing line 42 is turned on, the voltage level of the first input terminal of the comparator 5 will be substantially biased by the bias resistor 7. is pressed to the first voltage level, and when at least one of the switches 431 of the switch unit 43 electrically connected to the selected sensing line 42 is turned on, the voltage level of the first input terminal of the comparator 5 will be determined by the switch module 4 Substantially biased to the second voltage level.

The processing unit 82 also sets the drive signal output to a selected drive line 41 of the drive lines 41 when the comparison signal indicates that at least one of the switches 431 of the switch unit 43 electrically connected to the selected sense line 42 is turned on. be the second voltage level, and set the remaining driving signals to the first voltage level or a high impedance state, so that the comparison signal indicates the switch of the switch unit 43 electrically connected to the selected sensing line 42 and the selected driving line 41 431 whether conduction. When the voltage level of the first input terminal of the comparator 5 is substantially greater than the fourth voltage level, the comparison signal is pulled to the second voltage level substantially to indicate electrical connection to the selected sensing line 42 and the selected driving line 41 The switch 431 of the switch unit 43 is turned on, otherwise, the comparison signal is pulled to the first voltage level to indicate that the switch 431 of the switch unit 43 electrically connected to the selected sensing line 42 and the selected drive line 41 is not turned on. Pass.

It should be noted that when the switch 431 of the switch unit 43 electrically connected to the selected sensing line 42 and the selected driving line 41 is not turned on, the voltage level of the first input terminal of the comparator 5 will be substantially biased to The first voltage level, and when the switch 431 of the switch unit 43 electrically connected to the selected sensing line 42 and the selected driving line 41 is turned on, the voltage level of the first input terminal of the comparator 5 is substantially greater than or equal to the first voltage level 1/n times of the second voltage level, therefore, in theory, the fourth voltage level can achieve the purpose of judgment as long as it is between the first voltage level and 1/n times of the second voltage level, but in order to avoid Noise interference causes judgment errors. Preferably, the difference between the fourth voltage level and 1/n times the second voltage level is substantially greater than or equal to a preset limit.

The processing unit 82 also sets the state of the switch 431 of the switch unit 43 stored in the memory 81 when the comparison signal indicates that the switch 431 of the switch unit 43 electrically connected to the selected sensing line 42 and the selected drive line 41 is turned on. for a conduction state.

In this embodiment, the processing unit 82 includes a processor 821 and a switching resistor 822 . The processor 821 is used for outputting the driving signal, a reference current and the set of control signals, and receiving the comparison signal. The conversion resistor 822 is electrically connected to the processor 821 for converting the reference current into a reference signal. The processor 821 sets the states stored in the memory 81 as non-conducting states, and sets the driving signal, the reference current and the set of control signals, and is electrically connected to the selected sensing line 42 and the selected driving signal when the comparison signal indicates When the switch 431 of the switch unit 43 on the line 41 is turned on, the state of the switch 431 of the switch unit 43 stored in the memory 81 is set to be turned on.

It should be noted that the input device in this embodiment may be, for example, a keyboard device or a resistive touch device, and is not limited thereto. The comparator 5, the switching unit 6, the bias resistor 7 and the processing module 8 can be integrated into an integrated circuit, but can also be realized by multiple separate circuits.

To sum up the above, compared with the prior art, this embodiment has the following advantages: (1) the switch module 4 does not need to use a diode, which can save costs, and can also be realized by printing on a flexible board; (2) the resistance 432 The series-parallel connection situation is relatively simple, so it is not easy to misjudgment; (3) the processing module 8 can judge whether there is at least one conduction in all or part of the switch 431 at one time, and when it is judged that there is no switch 431 conduction Further judgment is omitted, so the total time for judging the respective states of the switches 431 is shorter; (4) the accuracy of the resistance of the resistor 432 is low; and (5) only one comparator 5 is needed. So the present embodiment can really achieve the purpose of the utility model.

Claims (4)

1. the input media that can eliminate terrible key comprises:

A switch module comprises: many drive wires, many lines of induction and a plurality of switch element; Each switch element be included in the described drive wire corresponding one and the described line of induction in a switch and a resistance of connecting between corresponding one, each switch switches between conducting and not conducting;

It is characterized in that this input media that can eliminate terrible key also comprises:

A comparer, comprise a first input end, second input end that receives a reference signal, and the output terminal of a comparison signal of an output, this comparer is in order to received signal and this reference signal of this first input end relatively, to obtain this comparison signal;

A switch unit is electrically connected to the first input end of the described line of induction and this comparer, and this switch unit is subjected to one group of control signal control switching, and in the described line of induction at least one is electrically connected to the first input end of this comparer;

A bias resistance has first end that is electrically connected to the first input end of this comparer, and second end that receives one first voltage level; And

A processing module, be electrically connected to described drive wire, this comparer and this switch unit, this processing module is clipped to described drive wire in order to export a plurality of drive signal branches, exports second input end of this reference signal to this comparer, and export this group control signal, and receive this comparison signal from the output terminal of this comparer to this switch unit.

2. the input media of eliminating terrible key according to claim 1 is characterized in that, this processing module comprises:

A reservoir stores the state of the switch of described switch element; And

A processing unit is electrically connected to this reservoir, in order to exporting described drive signal, this reference signal and this group control signal, and receives this comparison signal;

This processing unit is set the stored described state of this reservoir and is all a not on-state, and set described drive signal, this reference signal and this group control signal, and when this comparison signal was indicated the switch conduction of this switch element that is electrically connected to this selected line of induction and this selected drive wire, the state of setting the switch of this stored switch element of this reservoir was a conducting state.

3. the input media of eliminating terrible key according to claim 2 is characterized in that, this processing unit comprises:

A processor in order to exporting described drive signal, a reference current and this group control signal, and receives this comparison signal; And

A transfer resistance is electrically connected to this processor, in order to convert this reference current to this reference signal;

This processor is set the stored described state of this reservoir and is all this not on-state, and set described drive signal, this reference current and this group control signal, and when this comparison signal was indicated the switch conduction of this switch element that is electrically connected to this selected line of induction and this selected drive wire, the state of setting the switch of this stored switch element of this reservoir was this conducting state.

4. the input media of eliminating terrible key according to claim 1, it is characterized in that, this switch unit comprises a plurality of two passes of cutting, each is two cuts to close and comprises that is electrically connected in the described line of induction first end of corresponding one, second end that is electrically connected to the first input end of this comparer, and the 3rd end that receives this first voltage level, described two the incision closed in order to according to this group control signal, makes between this first end and this second end or conducting between this first end and the 3rd end.

Images