JPH0514979A - Wireless remote control reception circuit - Google Patents

Abstract

PURPOSE:To prevent malfunction by dividing the reception circuit into two, using the one for an output circuit for a switch, the other for a check circuit of an input pulse, and devising the check circuit to interrupt the connection between the output circuit and an operating device in a state of crosstalk. CONSTITUTION:When a switch SW on a remote control transmitter 10 is depressed, a radiated infrared ray pulse is received by a light receiving section 12 and an output signal is inputted to receivers IC14A, IC14B. Since no output signal is obtained from the receiver 14B, an output signal of an OR circuit 20 goes to an L level, a buffer circuit 18B is closed and the same signal as the receiver 14A is inputted to the receiver 14B from the light receiving section 12. A parallel output is produced from the receivers 14A, 14B, an output of the receiver 14B is inputted to a monostable multivibrator circuit 16, its output closes a buffer 18A to allow an output from the receiver 14A to be outputted to an operating device. Simultaneously, the buffer 18B is opened by the output from the receiver 14B through the circuit 20 to eliminate a pulse input to the receiver 14B and its output is turned off. The receiver 14B detects it in the case of crosstalk and turns off its output and then the output is stopped.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used in the field of wireless remote control.

The present invention relates to a wireless remote control receiver circuit using infrared rays, and particularly to detect noise or interference.
The present invention relates to an improved wireless recommon receiver circuit.

[0003]

2. Description of the Related Art Conventionally, infrared rays, which are less likely to malfunction, are often used in wireless remote controllers or wireless remote controllers, and communication is performed by converting signals into pulsed infrared rays by a switch input in a transmitter. In this case, since many dedicated ICs are commercially available for each circuit for pulse oscillation and reception, the wireless remote controller can be easily configured by selecting and using an appropriate IC from them.

[0004]

When a circuit is constructed using a conventional dedicated IC, an infrared pulse corresponding to a certain switch input is transmitted, the receiving IC checks the transmitted pulse, and the output corresponding to the switch input is output. I do. When there is interference such as interference with other remote controllers or noise during this communication, the normal reception IC cannot identify whether the input pulse is interference, noise or a legitimate signal, and outputs even if the switch is released. There is a malfunction that the screen remains untouched.

In order to prevent such a malfunction, an object of the present invention is to identify whether the input pulse is noise or interference, and if it is, connect with an operating device. The purpose of the present invention is to provide a wireless remote control receiver circuit capable of disconnecting.

[0006]

The above-described object is to provide a first receiver in a wireless remote control receiver circuit for receiving an infrared pulse from a transmitter and outputting an operation signal to an operating device such as a relay or a motor. And outputs a signal corresponding to the received infrared pulse, holds the output while the infrared pulse is present, and is connected in parallel with the reception output holding circuit connected to the device and the first receiver. A pulse train generation circuit for receiving output, which receives the same infrared pulse and outputs a signal corresponding to the pulse, is reset and repeats receiving the infrared pulse again,
This can be achieved by providing a control circuit for monitoring the loss of the pulse train due to noise or interference and disconnecting the receiver output holding circuit from the operating device.

[0007]

Even with the conventional receiver IC, when there is noise or interference from the first input, it is not possible to output the output corresponding to the input. Utilizing this characteristic, the receiving circuit is made into two systems, one is a circuit that holds the output corresponding to the switch after receiving the input, the other receiving circuit is after receiving the input,
A circuit that resets the output signal each time and receives again. Then, the output signal of the former circuit is conducted to the operating device only when the two circuits are receiving together, while the output signal of the latter circuit remains reset when there is noise or interference. , Detect this,
The output signal of the former circuit is cut off to make it non-conductive to the operating device.

In this way, the receiving circuit is divided into two systems, one is an output circuit for the switch and the other is an input pulse check circuit. During communication, noise or interference in the input pulse is always checked to check if interference or noise is mixed. At the time of, the check circuit disconnects the connection between the output circuit and the operating device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit block diagram of a main part showing the first embodiment, and FIG. 2 is a time chart showing an operation example thereof.

First, the switch S on the remote control transmitter 10
The infrared pulse transmitted by pressing W is received by the light receiving unit 1.
2 is received and input to the receiver ICs 14A and 14B. Since no output signal is output from the receiver IC 14B at the time of pulse input, the output signal of the OR circuit 20 is L
Therefore, the 3-state buffer 18B is closed, and the same signal as that of the receiver IC 14A is input to the receiver IC 14B from the light receiving unit 12. The light receiving unit 12 is composed of a filter, a phototransistor, an amplifier, etc.
Output amplified infrared pulse.

Then, as shown in FIG. 2, if the oscillation pulse is normal, the pulse for two cycles is detected internally in terms of function,
The receiver ICs 14A and 14B each perform parallel output corresponding to an input pulse. The parallel output is the OR circuit 2
This is done via a suitable plurality of signal lines as illustrated on the 0 input side.

At this time, the output of the receiver IC 14B passes through the OR circuit 20 and triggers the one-shot multivibrator 16, and the output (H) closes the 3-state buffer 18A and the output signal of the receiver IC 14A operates. It is output as a signal to operating devices such as a relay and a motor (not shown).

At the same time, the output (H) of the receiver IC 14B passing through the OR circuit 20 causes the state buffer 1
8B opens. Then, no pulse is input to the receiver IC 14B, and the output is OFF as shown in FIG.
(L). Further, since the output is turned off, the 3-state buffer 18B is closed and the pulse is input again, and as shown in FIG.
Turn on the output. Therefore, the output of the receiver IC14B is
It becomes a pulse train that repeats ON-OFF-ON.

As shown in FIG. 2, the one-shot multivibrator 16 is set to a time T'which is slightly longer than one period T (between ON and ON) of the output pulse from the receiver IC 14B, and the output B Trigger or retrigger (Ret.) Is applied at the rising edge of.

By controlling the 3-state buffer 7 with this one-shot output, the output signal of the receiver IC 14A is output as an operation signal without interruption, unless noise or interference occurs. Note that the retrigger is a function of restarting counting from the beginning when a trigger is applied while counting one shot.

Next, in the case of noise or interference, as shown in FIG. 2, the receiver IC 14B internally detects this and the output is stopped. After a certain period of time (dotted line portion), and after the count of the one-shot multivibrator 16 (retrigger set time) ends, the output stops (L), the three-state buffer 18A opens, and the receiver IC
The output signal of 14A is cut off, and the operation signal is not transmitted to the operation device. As a result, the output of the receiver IC 14A remains output even if there is noise, but the output as the operation signal can be stopped.

[0017]

[Effect] When multiple wireless remote controllers are present in the same room and each wireless transmitter is transmitting, the receiving circuit that has received interference can stop the operation output, and even if noise is input during communication. The operation output can be stopped, and malfunction due to noise or interference can be prevented.

[0018]

[Brief description of drawings]

FIG. 1 is a block diagram of a circuit main part showing an embodiment of the present invention.

FIG. 2 is a time chart showing an operation example thereof.

[Explanation of symbols]

 10 transmitter 12 light receiving part 14 receiver IC 16 one-shot multivibrator 18 3-state buffer 20 OR circuit

Claims (1)

Claim: What is claimed is: 1. A wireless remote control receiver circuit for receiving an infrared pulse from a transmitter and outputting an operation signal to an operating device such as a relay or a motor, the receiver having a first receiver, A signal corresponding to the infrared pulse is output, the output is held while the infrared pulse is present, the reception output holding circuit connected to the device and the first receiver are connected in parallel, and the same Each time it receives an infrared pulse and outputs a signal according to that pulse, it is reset and repeats receiving the infrared pulse again, monitoring the pulse train generation circuit of the reception output and the lack of the pulse train due to noise or interference In this case, the wireless remote control receiving circuit is provided with a receiver output holding circuit and a control circuit for disconnecting the connection between the operating device and the operating device.