JPH06100954B2 - Key input device malfunction prevention method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing malfunction of a key input device, and more particularly, in a remote controller that changes from a standby state to an operating state in response to a key input, the standby state after the operation. When returning to the state, it is possible to prevent a malfunction in which the standby state is not maintained and the state becomes the active state again due to the crosstalk as the key input signal of the key scan signal, and it is possible to reduce the power consumption. 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 judges the contents of an input key and drives an infrared light emitting diode or the like according to the key. Then, the remote control signal is transmitted to the light 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 small. This device is normally in a standby state (or HALT state, hereinafter referred to as a standby state) and enters an operating state in response to a key operation. Therefore, when the key is not operated, it is in a standby state and its power consumption is suppressed to a minute amount.

[Problems to be Solved] In such a remote controller, a key is operated to release the standby state, the operating state is entered, and the standby state is resumed after performing a predetermined operation. The level of the phase pulse signal that performs the key scan in the standby state is fixed to either the HIGH level (hereinafter “H”) or the LOW level (hereinafter “L”).

Therefore, a crosstalk signal is generated via the capacitance component of the key input circuit according to the change of the signal for fixing the level to the standby state, and this is fed back to the control circuit side as a key input change signal and It may be erroneously detected.

As a result, the control circuit accepts the key scan signal in the standby state as a key input signal, cancels the standby state, and starts an operation again, which causes a malfunction. Moreover, in this case, this malfunction causes wasteful power consumption.

The present invention solves the above-mentioned problems of the prior art, and prevents a malfunction that causes a crosstalk due to a key input after an operation and a re-operation state without being maintained in a standby state. 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 Problem] In the configuration of the malfunction prevention system of the key input device of the present invention for achieving such an object, the phase pulse signal is in the standby state when the input key is not operated. HI
In the key input device that is set to either the GH level or the LOW level and generates the output of the other level in the operating state, the input key determination circuit detects the phase pulse signal in the standby state. When the control circuit enters the operating state from the standby state, the phase pulse generation circuit is returned to the standby state after the specified operation, and the crosstalk signal generated in the key input circuit is the phase pulse in the standby state of the input key determination circuit. The input key determination circuit is returned to the standby state after a predetermined time interval at which the signal detection level is lowered.

[Operation] In this way, the input key determination circuit determines the key input, and after taking action according to the determination, first reset the phase pulse generation circuit to the standby state. After that, by shifting the input key determination circuit so that it returns to the standby state after a predetermined time interval, the input key determination circuit does not cause a false operation as a key input signal, and the control circuit of the key input device is eliminated. Are prevented from entering the operating state continuously. As a result, for example, in a remote controller operated by a battery, it is possible to reduce unnecessary power consumption of the battery.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

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

In FIG. 1, reference numeral 10 is 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. The key input circuit 2 is
Each input key 4 is connected to the intersection of the matrix wiring. The vertical wirings M ₁ , M ₂ , ... Mm are the scanning lines connected to the scanning terminals that receive the phase pulse signal from the control circuit 1, and the horizontal wirings N ₁ , N ₂ ,. Nn is the output line connected to its output terminal. Then, each scanning line M ₁ , M ₂ , ...
.., Mm are respectively connected to the phase output terminals of the phase pulse output circuit 6 of the control circuit 1, and the output lines N ₁ , N ₂ ,
, Nn are connected to the respective input terminals of the input key determination circuit 7 of the control circuit 1.

Here, the control circuit 1 includes a timing controller 8 that controls the operation timing of each circuit, the phase pulse output circuit 6, the input key determination circuit 7, the operation / signal output circuit 9, and the like. An external clock signal generator 8 generates a clock signal 8 and sends a timing control signal to each of the above circuits.

In the operating state, the phase pulse output circuit 6 outputs a pulse signal of “H” to the scanning lines M ₁ , M ₂ , which are vertical wiring of the key input circuit ₂ .
The phase pulse signals having different phases are sequentially transmitted to Mm as scanning pulses in accordance with the scanning timing. Then, when entering the standby state from the operating state, the HALT signal of the timing controller 8
"L" for each output terminal by being output to HALT control line 6a
Lock them in and keep them low during the waiting state.

The input key determination circuit 7 outputs the "L" phase pulse signal in the standby state to any one of the output lines N ₁ , N ₂ , ... By detecting it by appearing, it is detected that the key 4 has been operated, and a signal for activating the timing controller 8 is generated and sent to the timing controller 8.

When the timing controller 8 receives the activation signal as a result of the operation of the key 4 from the input key determination circuit 7, the timing controller 8 changes the signals of the HALT control lines 6a, 7a, 9a from "H" to "L", and the various signals are given. The phase pulse output circuit 6, the input key determination circuit 7, and the operation / signal output circuit 9 are released from the standby state and brought into the operating state.

As a result, all the circuits of the control circuit 1 enter the operating state, and the phase pulse output circuit 6 causes the timing controller 8 to operate.
A phase pulse signal is output under the control of the phase pulse signal, and one "H" output of this phase pulse signal is sent to the input key determination circuit 7 via the key 4 input according to the generation timing. Then, the input key determination circuit 7 determines the position of the input terminal and the input timing, and the input key determination circuit 7 calculates a signal corresponding to the input key in response to the determination of the input key 4. / Sent to the signal output circuit 9. The calculation / signal output circuit 9 receives this signal, generates a transmission signal code corresponding to the signal calculated according to the input key signal, and adds a code indicating the start of transmission to the head of the infrared emission device. It is output to 4 and this is driven for transmission processing.

When this transmission operation ends, the timing controller 8 receives an end signal from the arithmetic / signal output circuit 9, and the timing controller 8 generates a control signal for putting each circuit in a standby state after a certain time has elapsed after receiving this signal. , The timing controller 8 goes into the standby state. In this case, the timing controller 8 changes the signal of the HALT control line 6a for setting the phase pulse output circuit 6 to the HALT state from "L" to "H" first. To enter the standby state, and then, for example, after counting several tens of clock signals, set the input key determination circuit 7 to the HALT state by changing the signal of the HALT control line 7a from "L" to "H".
And put it in a standby state. The other circuits are also put in the standby state at any of the above timings.

By doing so, the input key determination circuit 7 is delayed by several tens of microseconds from the phase pulse output circuit 6 in the standby state.

FIG. 2 shows such a timing relationship, in which (a) is the control timing of the present invention.
(B) is the conventional control timing. Here, the delay time τ of several tens of the count number of the clock signal
Is a time sufficient for the crosstalk signal n generated by the input of the key 4 to fall below the detection level V _TH (threshold level) of the key input of the input key determination circuit 7.
After that, the input key determination circuit 7 starts the detection operation of the standby state, so that the malfunction due to the crosstalk can be prevented. Therefore, the timing controller 8 does not operate continuously.

As described above, the circuit configuration of the remote controller is an example, and the present invention is not limited to this. The delay time τ is selected according to the crosstalk level of the key input circuit. However, the larger the number of keys, the larger the crosstalk. Therefore, a large delay time should be set.

In the embodiment, the delay time τ is set by delaying the generation timing of the HALT signal of the controller.However, for example, a plurality of logic circuits are connected in cascade and a delay circuit by a hard circuit is connected to the HALT control line of the input key determination circuit. It may be inserted and delayed.

[Effect of the Invention] As can be understood from the above description, in the present invention,
The input key is judged by the input key judgment circuit,
After performing processing according to the determination according to this determination, first, the phase pulse generation circuit is returned to the standby state first,
After that, by shifting the input key determination circuit so that it returns to the standby state after a predetermined time interval, there is no malfunction that the input key determination circuit erroneously detects as a key input signal, and the control circuit of the key input device is continuously operated. Then, the operation state is prevented. As a result, for example, in a remote controller operated by a battery, it is possible to reduce unnecessary power consumption of the battery.

[Brief description of drawings]

FIG. 1 is a block diagram of a remote controller of an embodiment to which a malfunction prevention system for a key input device of the present invention is applied, and FIG. 2 is a timing chart of its operation. 1 ... Control circuit, 2 ... Key input circuit, 3 ... Infrared light emitter, 4 ... Input key, 5 ... Clock signal generating oscillator, 6 ... Phase pulse output circuit, 7 ... Input key determination circuit , 8 ... Timing controller, 9 ... Calculation / signal output circuit, 10 ... Remote controller.

Claims (1)

[Claims] 1. A plurality of input keys, a plurality of scanning terminals which receive signals for scanning these input keys, and a plurality of which generate an output signal corresponding to a scan corresponding to an operated key. A key input circuit having an output terminal, a phase pulse generating circuit for scanning the key input circuit by sending phase pulse signals having phases corresponding to the plurality of scanning terminals, respectively, and a phase pulse generating circuit for generating the plurality of output terminals An input key determination circuit for determining a key input in response to a signal, and performing a predetermined operation according to the determination result of the input key determination circuit to return to a standby state. When the key is not operated, the phase pulse signal is set to either the HIGH level or the LOW level in the standby state, and the other level is output in the operating state. In the key input device for generating, the control circuit enters the operating state from the standby state when the input key determination circuit detects the phase pulse signal in the standby state, and the phase pulse generating circuit is turned on after the predetermined operation. The input key determination is performed after a predetermined time interval in which the crosstalk signal generated in the key input circuit is returned to the standby state first and falls below the detection level of the phase pulse signal in the standby state of the input key determination circuit. Key input device malfunction prevention method characterized by returning the circuit to the standby state.