JPH0244920A - Malfunction preventing system for key input device - Google Patents

Abstract

PURPOSE:To evade malfunction to be caused by mis-detection of a signal as a key entry signal by an input key deciding circuit by restoring a phase pulse generating circuit earlier after the execution of the processing in response to the decision of the input key discrimination circuit into the standby state and then restoring the input key deciding circuit at a prescribed time interval thereafter into the standby state. CONSTITUTION:The input key deciding circuit 7 decides an entered key 4 and applies the processing in response to the discrimination according to the decision. Then the phase pulse output circuit 6 is restored into the standby state earlier, then the circuit 7 is restored into the standby state with a prescribed time interval. Thus, malfunction caused by the mis-detection of a signal to be a key entry signal by the circuit 7 is evaded and the event of a control circuit 1 of the key entry circuit 2 reaching the opening state continuously is prevented and useless power consumption of the battery is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing malfunction of a key input device, and more particularly, to a method for preventing malfunction of a key input device. It is possible to prevent malfunctions in which the standby state is not maintained and return to the operating state due to crosstalk between the key scan signal and the key input signal when returning to the state, and to reduce power consumption. The present invention relates to a method for preventing malfunction of a key input device.

[Prior Art] A remote controller is generally composed of a one-chip processor and a matrix-connected key switch, etc., and determines the contents of an input key and drives an infrared light emitting diode, etc. according to the key. and sends a remote control signal to the receiver on the main body of the device.

In such a remote controller, it is important that power is obtained from one or several dry batteries and the power consumption is low.

This device is normally in a standby state (or HALT state).

It is placed in a standby state (hereinafter referred to as a standby state) and enters an operating state in response to a key operation. Therefore, when no key is operated, the device is in a standby state and its power consumption is kept to a minimum.

[Problem to be Solved] In such a remote controller, when a key is operated, the standby state is canceled and the operating state is entered, and after performing a predetermined operation, the remote controller returns to the standby state. A phase pulse signal for performing a key scan is fixed at one of a standby level, a HIGH level (hereinafter referred to as "H"), or a LOW level (hereinafter referred to as "L").

Therefore, in response to changes in the signal for fixing the level to the standby state, a crosstalk signal is generated via the capacitance component of the key input circuit, and this is fed back to the control circuit side as a key input change signal and becomes the key input signal. There are many cases where false positives are detected.

As a result, the control circuit receives the key scan signal in the standby state as a key input signal, and the control circuit is released from the standby state, causing a malfunction in which the operation is started again. Moreover, in this case, power is wasted due to this malfunction.

The present invention solves the problems of the prior art, and prevents malfunctions in which the standby state is not maintained after operation due to crosstalk caused by key input, and the operation resumes. An object of the present invention is to provide a malfunction prevention method for a key input device that can suppress power consumption.

[Means for Solving the Problems] In order to achieve such an object, the key input device of the present invention has a malfunction prevention force type configuration in which the key input device is in a standby state when the input key is not operated, and a phase pulse signal is output. is H
In a key input device that is set to either the IGH level or the LOW level and generates an output at the other level in the operating state, the input key determination circuit detects a phase pulse signal in the standby state. When the control circuit enters the operating state from the standby state, and after a predetermined operation, the phase pulse generation circuit is returned to the standby state first, and the crosstalk signal generated in the key input circuit is converted into a phase pulse in the input key determination circuit's standby state. The input key determination circuit is returned to the standby state after a predetermined time interval at which the signal falls below the detection level.

[Operation: After the input key determination circuit determines the input key and performs processing according to the determination, the phase pulse generation circuit is first returned to the standby state. By returning the input key determination circuit to the standby state after a predetermined time interval, the input key determination circuit can eliminate malfunctions in which it erroneously detects a key input signal, and the control circuit of the key input device can is prevented from entering the operating state continuously. As a result, for example, in a remote controller operated by a battery, unnecessary power consumption of the battery can be reduced.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a remote controller according to an embodiment of the invention to which the key input device malfunction prevention method is applied, and FIG. 2 is a timing chart of its operation.

In FIG. 1, reference numeral 10 denotes a remote controller, which is composed of a control circuit 1, a key input circuit 2, and an infrared light emitter 3 such as an LED. Key input circuit 2
In this case, each person's key 4 is connected to the intersection of the matrix = 5-1 sox wiring, and the vertical wiring Ml
+ N2 , . . . , Mm are the scanning lines connected to the scanning terminals that receive the phase pulse signal from the control circuit 1, and the horizontal wiring NI T N2 + . . . 05Nn is connected to the output terminals thereof. This is the output line. Each scanning line Ml + N2 + @...+ Mm is connected to each phase output terminal of the phase pulse output circuit 6 of the control circuit 1, and each output line N1 + N2 +
·φ·, Nn are connected to each input terminal of the input key determination circuit 7 of the control circuit 1, respectively.

Here, the control circuit 1 includes a timing controller 8 that controls the operation timing of each circuit, the above-mentioned phase pulse output circuit 6, input key determination circuit 7, calculation/signal/output circuit 9, etc. The timing controller 8 includes an external clock signal generation oscillator 5.
A clock signal is generated and a timing control signal is sent to each of the circuits described above.

In the operating state, the phase pulse output circuit 6 sends a pulse signal of "H+1" to the scanning line M, which is a vertical wiring of the key input circuit 2.
19M2 T...", phase pulse signals with different phases are sequentially sent to IMm as scanning pulses in accordance with the scanning timing. Then, when entering the standby state from the operating state, the HALT of the timing controller 8 is activated. By outputting a signal to the HALT control line 6a, each output terminal is fixed at "L" and maintained at "L" during the standby state.

The input key determination circuit 7 determines that the phase pulse signal of "L I+" in the standby state appears on one of the output lines Nl+ N2 + . Therefore, by detecting it, key 4
detects that the timing controller 8 has been operated.
The timing controller 8 generates a signal to start the timing controller 8 and sends it to the timing controller 8.

When the timing controller 8 receives a start signal from the input key determination circuit 7 as a result of the key 4 being operated, the timing controller 8 or the HALT control lines 8a, 7a, 9
The signal a is changed from "H" to L to release each phase pulse output circuit 6, input key determination circuit 7, and arithmetic/signal output circuit 9 from the standby state and put them into the operating state.

As a result, all the circuits of the control circuit 1 enter the operating state, the phase pulse output circuit 6 is controlled by the timing controller 8, and outputs a phase pulse signal, and the "H" output of one of the phase pulse signals is It is sent to the input key determination circuit 7 via the input key 4 according to the generation timing.Then, the input key determination circuit 7 determines whether it is input based on the position of the input terminal and the input timing. A signal corresponding to the key input according to the determination of the key 4 is sent from the input key determination circuit 7 to the arithmetic/signal output circuit 9.The arithmetic/signal output circuit 9 receives this signal and A transmission signal code corresponding to the key signal is generated by calculation, a code indicating the start of transmission is added to the beginning of the code, and the code is output to the infrared emitter 4 to drive it and perform transmission processing. do.

When this transmission operation is completed, the timing controller 8 receives the completion signal from the calculation/signal output circuit 9, and the timing controller 8 generates a control signal to put each circuit in a standby state after a certain period of time after receiving this signal. , the timing controller 8 enters the standby state, but in this case, the timing controller 8 first changes the signal on the HALT control line 6a, which puts the phase pulse output circuit 6 into the HALT state, from "L" to "H". The HALT control line 7 puts the input key determination circuit 7 into the HALT state after counting several tens of clock signals.
The signal a is changed from "LH" to "H" to enter a standby state.

Note that other circuits are also put into a standby state at any of the above timings.

By doing so, the input key determination circuit 7 enters the standby state with a delay of several tens of microseconds from the phase pulse output circuit 6.

Such a timing relationship is shown in FIG. 2, in which (a) is the timing of the control of the present invention, and (
b) is the conventional control timing. Here, the delay time τ of several 10-10 counts of the previous clock signal is such that the crosstalk signal n generated by the input of the key 4 is at the detection level of the key input of the input key determination circuit 7 (VT)! (threshold level), after which the input key determination circuit 7 enters the standby state detection operation, thereby making it possible to prevent malfunctions due to crosstalk. therefore,
The timing controller 8 does not operate continuously.

Although the above explanation has been made, the circuit configuration of the remote controller is merely an example, and the present invention is not limited to this. Also, the delay time τ is selected depending on the crosstalk level of the key input circuit. As the number of keys increases, the crosstalk also increases, so a large number of delay times should be set.

In the embodiment, the delay time τ is set to delay the generation timing of the HALT signal of the controller. It is also possible to delay the delay by inserting the

[Effects of the Invention] As can be understood from the explanation below, in this invention, the input key determination circuit determines the input key, and in accordance with this determination, processing is performed in accordance with the determination. Afterwards, first return the phase pulse generation circuit to the standby state,
After that, by shifting the input key determination circuit to return to the standby state at a predetermined time interval, the input key determination circuit will no longer malfunction in erroneously detecting a key input signal, and the control circuit of the key input device will continue to operate. is prevented from entering the operating state. As a result, for example, in a remote controller operated by a battery, unnecessary power consumption of the battery can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a remote controller according to an embodiment of the present invention to which the key input device malfunction prevention method is applied, and FIG. 2 is a timing chart of its operation. DESCRIPTION OF SYMBOLS 1... Control circuit, 2... Key input circuit, 3... Infrared emitter, 4... Input key 15... Clock signal generation vibrator, 6... Phase pulse output circuit, 7... ...Input key determination circuit, 8...Timing controller, 9
... Arithmetic/signal output circuit, 10... Remote controller.

Claims (1)

[Claims] (1) A plurality of input keys, a plurality of scanning terminals that receive signals for scanning these input keys, and a plurality of output terminals that generate output signals corresponding to the scanning in response to the operated keys. a key input circuit having a key input circuit; a phase pulse generation circuit that scans the key input circuit by transmitting a phase pulse signal having a phase corresponding to each of the plurality of scanning terminals; and a signal generated at the plurality of output terminals. an input key determination circuit that determines the input key based on the input key, and a control circuit that performs a predetermined operation and returns to a standby state according to the determination result of the input key determination circuit, When the phase pulse signal is in the standby state when not operated, the phase pulse signal is at HIGH level and LOW level.
When the input key determination circuit detects the phase pulse signal in the standby state in a key input device that is set to one of the levels and generates an output at the other level in the operating state. The control circuit enters the operating state from the standby state, and after the predetermined operation, the phase pulse generation circuit is first returned to the standby state, so that the crosstalk signal generated in the key input circuit is transmitted to the input key determination circuit. A method for preventing malfunction of a key input device, characterized in that the input key determination circuit is returned to a standby state after a predetermined time interval at which the detection level of a phase pulse signal becomes lower than a detection level in a standby state.