JP2001145184A - Remote control signal receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate pulse width errors which occurs, when remote control signals are demodulated from infrared-ray carrier signals. SOLUTION: An infrared-ray receiving section 201 receives infrared-ray carrier signals from an infrared-ray remote controller 100 and an infrared-ray carrier demodulating section 202 demodulates remote control signals, by integrating the received signals by means of an integration circuit composed of a capacitor and a resistor. When the section 202 demodulates the remote control signals, an error is produced in the pulse width of the demodulated remote control signals, because the discharge from the capacitor continues, even if the pulse of the remote control signals becomes low level signals. A waveform correcting section 203 for the remote control signals integrates the remote control signals with a long time constant in the forefront section of the pulse of the remote control signals from the demodulating section 202 and with a short time constant in the terminal section of the pulse. Then the section 203 shapes the waveform of the remote control signals into a rectangular waveform, depending on the integrated results, that is, whether the results are higher than a reference level. Since the remote control signals are integrated with the long time constant in the forefront section of the pulse, such an error is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control signal receiving apparatus for receiving an infrared carrier signal transmitted by an infrared remote control unit or the like of household electric appliances and extracting a remote control signal.

[0002]

2. Description of the Related Art Conventionally, video equipment, audio equipment,
2. Description of the Related Art Various home electric appliances such as air conditioners can be remotely operated by an infrared remote control unit (also referred to as an infrared remote control) in order to enhance convenience. Many infrared remote controllers generate an infrared carrier signal in which an infrared pulse train of a predetermined cycle is modulated on / off by a remote control signal having a pulse width longer than the above cycle, and this infrared carrier signal is transmitted to a controlled device such as the home electric appliance. Send. Upon receiving the infrared carrier signal from the infrared remote controller, the controlled device converts the infrared carrier signal into an electric signal and then demodulates the remote control signal. Then, various operations are performed based on the obtained remote control signal. When demodulating the remote control signal, an error occurs in the pulse width of the remote control signal. However, the controlled device is designed to allow a certain range of error, and the pulse width error does not usually cause a problem. In addition, as the infrared carrier signal, a signal conforming to the regulations described in "Prevention of Malfunction of Infrared Remote Control Home Appliance" issued by the Home Appliances Association is usually used.

[0003] The infrared carrier signal is originally transmitted directly from the infrared remote controller to the controlled device, but a relay device is used to remotely control a device installed in another room. Can be That is, the infrared carrier signal from the infrared remote controller is once received by the relay device, and transmitted to the controlled device via the relay device.
However, when the relay device is used, the error of the pulse width accumulates, so that the error may exceed the permissible range on the controlled device side and cause a problem.

Hereinafter, this problem will be described in detail with reference to the drawings. FIG. 6 is a block diagram showing a conventional infrared remote control signal transmission / reception system, and FIG. 7 is a waveform diagram showing signals of various parts in the transmission system of FIG. In the infrared remote control signal transmission / reception system 110, the infrared remote control 100 is located in the room 1 and the controlled device is located in the room 2. In the room 1, a transmission unit 2 forming a relay device is provided.
00, while a receiving unit 400 as a relay device is installed in the room 2.

[0005] As shown in FIG. 6, the transmitting unit 200 includes an infrared light receiving section 201 and an infrared carrier demodulating section 20.
2. Remote control signal modulation section 204 and transmission section 205
It is comprised including. On the other hand, the receiving unit 400
Is configured to include a receiving unit 401, a remote control signal demodulating unit 402, an infrared carrier modulating unit 403, and an infrared light emitting unit 404.

As shown in FIG. 7, the infrared remote controller 100 generates a remote control signal having a pulse width of A and a pulse interval of B, modulates an infrared pulse train with the remote control signal, and transmits the modulated pulse train to the transmission unit 200. . The frequency of the infrared pulse train is, for example, 38 KHz. The infrared pulse train is transmitted while the pulse of the remote control signal is at a high level, and the transmission of the infrared pulse train is stopped while the pulse of the remote control signal is at a low level. as a result,
An infrared carrier signal as shown in FIG. 7 is formed and transmitted to the transmission unit 200.

In the transmission unit 200, the infrared light receiving section 20
1 receives the infrared carrier signal and converts it into an electric signal.
And demodulate and extract a remote control signal from the output signal. Specifically, the infrared carrier demodulation unit 202 first integrates the output signal of the light receiving unit 201 by an integration circuit including a capacitor and a resistor. As a result, an integral / demodulated waveform as shown in FIG. 7 is obtained. Thereafter, the infrared carrier demodulation unit 202 compares the integrated / demodulated waveform with the voltage of the predetermined determination level 102, and outputs a high-level voltage when the demodulated waveform is equal to or higher than the determination level 102, as shown in FIG. Generate a demodulated remote control signal.

Here, the integration / demodulation waveform shown in FIG.
After the high-level period of the original remote control signal ends,
Since the discharge of the capacitor constituting the integration circuit of the demodulation unit continues, the waveform has a waveform that does not immediately become zero but gradually falls. Therefore, from the relationship with the determination level 102, the demodulated remote control signal is Te
Only the pulse width becomes longer, which is an error.

Thereafter, a remote control signal modulation section 204 modulates the carrier signal of the electric signal with a remote control signal demodulated by the infrared carrier demodulation section 202, and a transmission section 205 converts the carrier signal modulated by the remote control signal, for example, from a coaxial cable. The data is transmitted to the receiving unit 400 via the communication line 300. The communication line 300 may be an optical cable or a wireless transmission path.

In receiving unit 400, receiving section 401 receives the modulated carrier signal from communication line 300 and supplies it to remote control signal demodulation section 402, and receives signal from remote control signal demodulation section 4.
02 demodulates the remote control signal from the modulated carrier signal.
Infrared carrier modulation section 403 and infrared light emitting section 404
Operates in the same manner as the infrared remote controller 100, and the infrared light emitting section 404 has a cycle of, for example, 38 KH under the control of the infrared carrier modulation section 403 based on the remote control signal.
A second infrared carrier signal (FIG. 7) in which the z infrared pulse train is turned on / off is transmitted to the controlled device.

In the controlled device, the second infrared carrier signal is received by the infrared light receiving section 501 and converted into an electric signal, and the infrared carrier demodulation section 502 converts the remote control signal from the second infrared carrier signal converted into the electric signal. The demodulated and extracted data is supplied to an operation control unit 503 that controls the operation of the controlled device based on a remote control signal. Here, the infrared carrier demodulation unit 502 is connected to the transmission unit 200 described above.
As with the infrared carrier demodulation unit 202, the output signal of the light receiving unit is first integrated by an integration circuit including a capacitor and a resistor. As a result, as shown in FIG.
A demodulated waveform is obtained. Then, the infrared carrier demodulation unit 5
02 compares the integrated / demodulated waveform with the voltage of the predetermined judgment level 104, and outputs a high-level voltage when the demodulated waveform is equal to or higher than the judgment level 104. Generate a signal.

Here, the integration / demodulation waveform on the device side shown in FIG. 7 is also obtained after the duration of the infrared carrier signal ends.
Since the discharge of the capacitor constituting the integration circuit of the demodulation unit continues, the waveform has a waveform that does not immediately become zero but gradually falls. Therefore, from the relationship with the determination level 104, the demodulated remote control signal is smaller than the original pulse width by Te.
The pulse width becomes longer by two, which is an error.

Therefore, as can be seen from FIG. 7, the pulse width of the remote control signal supplied to the operation control unit 503 is longer by Te + Te2 than the width A of the pulse of the remote control signal internally generated by the infrared remote controller 100. On the contrary, the pulse interval B 'is shorter than the original pulse interval B by the same length. That is, the controlled device 5 via the transmission unit 200 and the reception unit 400
When remotely controlling 00, the error of the pulse width is accumulated, and the error of the pulse width is greatly increased as compared with the case where the controlled device 500 is directly controlled. As a result, these errors may exceed the allowable range when the control information is extracted from the remote control signal in the controlled device 500, making remote control of the controlled device 500 difficult.

[0014] Such a problem can be solved by transmitting the infrared carrier signal as it is to the controlled device without demodulating and remodulating the remote control signal when relaying the infrared carrier signal. In that case, a new problem occurs as described below. FIG. 8 is a block diagram showing an example of a conventional infrared remote control signal transmission / reception system which does not perform demodulation and re-modulation of an infrared carrier signal. FIG. 9 is a waveform diagram showing the operation of the infrared remote control signal transmission / reception system of FIG. In the figure, the same elements as those in FIGS. 6 and 7 are denoted by the same reference numerals.

This infrared remote control signal transmission / reception system 1
In step 06, the transmission unit 200A does not include the infrared carrier demodulation unit 202, and directly modulates the carrier signal of the electric signal with the remote control signal modulation unit 204 using the infrared carrier signal received by the infrared light receiving unit 201 and converted into the electric signal. It has a configuration. Therefore, when the signal is modulated into, for example, an ASK signal by the remote control signal modulator 204, the signal transmitted to the communication line 300 has a waveform as shown in FIG.

In the receiving unit 400A, this signal is received by the receiving unit 401 and demodulated by the demodulating unit 402, so that a demodulated signal as shown in FIG. 9 is obtained. And
The infrared light emitting section 404 is controlled based on the demodulated signal, and transmits a second infrared carrier signal having the same waveform as the demodulated signal to the controlled device 500. In the controlled device 500, an integration / demodulation waveform (FIG. 9) is first obtained by the above-described operation of the infrared carrier demodulation unit 202, and further, a remote control signal on the device side is obtained by waveform shaping. And
The pulse width A ′ of this remote control signal is
0 is longer than the pulse width A of the generated remote control signal by Te, while the pulse interval B ′ is longer than the original pulse interval B by T.
e is shorter.

In this method, the controlled device 500 is executed only once.
, Demodulation is performed, so that errors do not accumulate, but only Te, and the controlled device 500 can correctly acquire control information from the remote control signal. However, when demodulation and re-modulation are not performed by the relay device, the receiving unit 400A needs to capture an infrared carrier signal of 30 KHz to 40 KHz, and a microcomputer that controls the capture of the signal has a high speed. Must be used.

When data processing such as adding the device number of the transmission unit 200 to the remote control signal is performed by the transmission unit 200A, such processing must be performed using a high-frequency infrared carrier signal. There is a problem that it becomes very difficult. Furthermore, it is necessary to transmit a high-frequency carrier signal through the communication line 300, so that the frequency band of the transmission signal is widened, so that there is a problem that the modulation method is limited. Therefore, it is not advisable to adopt a method in which the relay apparatus does not demodulate and remodulate the infrared carrier signal.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to provide a remote control signal receiving apparatus which does not cause an error in pulse width when demodulating a remote control signal from an infrared carrier signal.

[0020]

According to the present invention, there is provided a light receiving section for receiving an infrared carrier signal obtained by modulating an infrared pulse train with a remote control signal and converting the signal into an electric signal, and an output signal of the light receiving section. And a demodulation unit for demodulating the remote control signal by shaping the integration result into a waveform, and demodulating the remote control signal by shaping the waveform of the integration result, wherein the demodulation unit demodulates the remote control signal. A waveform correction unit that changes the pulse width of the remote control signal, the waveform correction unit integrates the remote control signal with a long time constant at the beginning of the pulse of the remote control signal from the demodulation unit, and the pulse end of the remote control signal at the pulse end. A second integration circuit including a second capacitor and a second resistor for integrating the remote control signal with a short time constant;
And a waveform shaping unit for shaping the waveform of the remote control signal integrated by the integrating circuit into a rectangular waveform based on whether or not the signal is larger than a reference level, and outputting the result as a remote control signal after waveform correction. It is characterized by the following.

In the remote control signal receiving apparatus according to the present invention, the second integration circuit of the waveform correction unit integrates the remote control signal with a long time constant at the beginning of the pulse of the remote control signal from the demodulation unit, and generates the pulse of the remote control signal. At the end, the remote control signal is integrated with a short time constant. The waveform shaping unit shapes the remote control signal integrated by the second integration circuit into a rectangular waveform based on whether the signal is larger than the reference level, and outputs the result as a remote control signal after the waveform correction. .

Therefore, even if the end of the pulse of the remote controller signal demodulated by the demodulation unit is later than the end of the original remote control signal, the second integration circuit starts the pulse of the remote control signal from the demodulation unit. Since the signal is integrated with a long time constant in the section, the pulse head of the remote control signal after the waveform correction is delayed from the head of the original remote control signal. On the other hand, the delay of the pulse end portion of the remote control signal after the waveform correction is small because it is integrated with a short time constant. As a result, by properly setting the time constant of the second integration circuit and the reference level, the pulse width of the remote control signal after the waveform correction can be made to match the pulse width of the original remote control signal.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an infrared remote control signal transmission / reception system including a transmission unit as an example of a remote control signal reception device according to the present invention.
FIG. 3 is a circuit diagram showing in detail a remote control signal waveform correction unit constituting the transmission unit of FIG. 1, and FIG. 3 is a waveform diagram showing an operation of the infrared remote control signal transmission / reception system of FIG. In the drawing, the same elements as those in FIG. 6 and the like are denoted by the same reference numerals, and a detailed description thereof will be omitted here.

The infrared remote control signal transmission / reception system 2 shown in FIG. 1 is different from the system shown in FIG. 6 in that the transmission unit 2 is a remote control signal receiving apparatus of the embodiment.
00B, between the infrared carrier demodulation unit 202 and the remote control signal modulation unit 204, the remote control signal waveform correction unit 20
3 is provided. As shown in FIG. 2, the remote control signal waveform correction unit 203 integrates the remote control signal with a long time constant at the head of the pulse of the remote control signal from the infrared carrier demodulation unit 202 and at the terminal of the pulse of the remote control signal. Integrate the remote control signal with a short time constant,
Capacitor C1 (second capacitor according to the present invention)
And an integration circuit 6 (second integration circuit) including a resistance 4 (second resistance). The remote control signal waveform correction unit 203 shapes the remote control signal integrated by the integration circuit 6 into a rectangular waveform based on whether the signal is larger than a reference level, and outputs the result as a remote control signal after the waveform correction. The waveform shaping unit 8 is provided.

The resistor 4 includes a resistor R2 (third resistor) and a resistor R1 (fourth resistor), and a series circuit of the capacitor C1 and the resistor R2 is connected between a + 5V power supply and the ground. One end of the resistor R1 is connected to the capacitor C1 and the resistor R2.
The other end of the resistor R1 is controlled to be in an open state or the same potential as the ground based on the magnitude of the remote control signal from the demodulation unit 202.
The resistance of the resistor R2 is large, and the resistance of the resistor R1 is small.

The integrating circuit 6 outputs an output signal to the output terminal 14 based on the comparison result of the voltages at the first and second input terminals 10 and 12.
The first input terminal 10 (positive polarity) receives a remote control signal from the infrared carrier demodulation unit 202, and the second input terminal 12 (negative polarity) Resistance) includes resistors R3 and R3
4, a reference voltage obtained by dividing the power supply voltage (+5 V) is applied, and the output terminal 14 is connected to the other end of the resistor R1. The output of the first comparator 16 is an open collector.

The waveform shaping section 8 includes a second comparator. A first input terminal 10 (positive polarity) of the second comparator 17 is connected to a common connection point 7 between the capacitor C1 and the resistor R2. A reference voltage obtained by dividing the power supply voltage by the resistors R5 and R6 is applied to the second input terminal 12 (negative polarity). The output terminal 14 of the second comparator is pulled up to a power supply by a resistor R7.

Next, the operation of the infrared remote control signal transmission / reception system 2 configured as described above will be described focusing on the operation of the transmission unit 200B. Infrared remote control 10
0 internally generates, for example, a remote control signal having a pulse width as shown in FIG. 3, and modulates an on / off infrared pulse train with the remote control signal to transmit an infrared carrier signal (FIG. 3) to the transmitting unit 200B. I do. In the transmission unit 200B, the infrared light receiving unit 201 receives the infrared carrier signal and converts it into an electric signal. The infrared carrier demodulation unit 202 demodulates a remote control signal from the output signal of the infrared carrier demodulation unit 202. As already described in detail, the infrared carrier demodulation unit 202 first generates a demodulated signal of the integration / demodulation waveform shown in FIG. 3 by its integration circuit, and then shapes the waveform into a rectangular waveform to obtain a demodulated remote control signal. Output. This remote control signal has an error of time Te in its pulse width as shown in FIG. 3 and as already described.

The demodulated remote control signal is supplied to the remote control signal waveform correction section 203, and specifically, is input to the first input terminal 10 of the first comparator 16 shown in FIG. In this example, the waveform of the remote control signal input to the first comparator 16 is not rounded. Therefore, when the remote control signal goes high, the output of the first comparator 16 whose output is an open collector is immediately output. It becomes open. Therefore, the capacitor C1 is connected to the resistor R
2, the voltage of the first input terminal 10 of the second comparator 17 is gradually increased as shown in FIG. This rate of rise is determined by the resistance R
2 is slow because of the large resistance value.

Thereafter, when the remote control signal input to the first input terminal 10 of the first comparator 16 becomes low level, the output of the first comparator 16 becomes the ground potential, and therefore, the capacitor C1 becomes a resistor having a small resistance value. R1 is connected in parallel, discharges rapidly, and the potential of the first input terminal 10 of the second comparator 17 becomes almost at the same time as the remote control signal goes low as shown in FIG. It becomes the ground level.

The second comparator 17 compares the voltage of the first input terminal 10 with the reference voltage Vref. If the voltage of the first input terminal 10 exceeds the reference voltage Vref, the second comparator 17 goes to a high level. When the voltage of the first input terminal 10 falls below the reference voltage Vref, a low level (ground level) voltage is output. Therefore, as shown in FIG. 3, the output voltage of the second comparator, that is, the remote control signal output by the remote control signal waveform correction unit 203 is a time from the timing when the remote control signal from the infrared carrier demodulation unit 202 changes to a high level. It goes high at a timing delayed by Ts. On the other hand, at the timing when the remote control signal from the infrared carrier demodulation unit 202 changes to the low level, the signal changes to the low level with almost no delay.

The time Ts can be made to coincide with the time Te by appropriately setting the time constant of the capacitor C1 and the resistor R2 and the reference voltage Vref. As a result, the remote control signal waveform correction unit 203 outputs The pulse width A ′ and the pulse interval B ′ of the remote control signal to be transmitted are both the pulse width A of the remote control signal generated by the infrared remote control 100,
It corresponds to the pulse interval B. That is, in the transmission unit 200B of the present embodiment, errors in the pulse width and pulse interval of the remote control signal that occur in the conventional transmission unit are eliminated.

Therefore, the error in the pulse width of the remote control signal occurs only when demodulation is performed in the controlled device 500, and the error can be tolerated.
The control information can be correctly extracted by the remote control signal demodulated from the infrared carrier signal received from the receiving unit 400, and the operation can be reliably performed based on the remote operation by the infrared remote control 100.

Next, a second embodiment of the present invention will be described. FIG. 4 is a block diagram showing an infrared remote control signal transmission / reception system according to the second embodiment, and FIG. 5 is a circuit diagram specifically showing a remote control signal waveform correction unit constituting the second embodiment. In the drawings, the same elements as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted here.

The infrared remote control signal transmission / reception system 18 of the second embodiment differs from the above-described system in the configuration of the transmission unit 200C, and the remote control signal waveform correction section 203 is replaced with a remote control signal waveform correction section 203A.
Then, a waveform correction width setting unit 206 is added. The remote control signal waveform correction unit 203A, as shown in FIG.
The method of supplying the reference voltage to the second input terminal 12 of the second comparator 17 is different from that of the above embodiment.
That is, in the remote control signal waveform correction unit 203A, the second
The reference voltage Vref is supplied to the second input terminal 12 of the comparator 17 from the waveform correction width setting unit 206,
The reference voltage is not fixed as in the above embodiment, but is variable by the waveform correction width setting unit 206.

Therefore, even if the actual error time Te of the remote control signal pulse width shown in FIG. 3 is different from the time assumed at the time of design, the waveform correction width setting unit is not used in the second embodiment. The reference voltage Vref is adjusted by 206 so that the time Ts matches the time Te, and the pulse width of the remote control signal output by the remote control signal waveform correction unit 203A completely matches the pulse width of the remote control signal generated by the infrared remote control 100. be able to.

[0037]

As described above, according to the present invention, a light receiving section for receiving an infrared carrier signal obtained by modulating an infrared pulse train with a remote control signal and converting the signal into an electric signal, and a capacitor and a resistor for converting the output signal of the light receiving section into an electric signal. And a demodulator for demodulating the remote control signal by integrating the integration circuit and shaping the waveform of the integration result, wherein the demodulator changes a pulse width of the remote control signal demodulated by the demodulator. A waveform correction unit, wherein the waveform correction unit integrates the remote control signal with a long time constant at the beginning of a pulse of the remote control signal from the demodulation unit and a short time constant at a pulse end of the remote control signal. A second integration circuit including a second capacitor and a second resistor for integrating a signal, and the remote control signal integrated by the second integration circuit , The signal is waveform-shaped into a rectangular waveform based on whether greater than the reference level, characterized in that it includes a waveform shaping section for outputting the results as a remote control signal after waveform correction.

In the remote control signal receiving apparatus according to the present invention, the second integration circuit of the waveform correction section integrates the remote control signal with a long time constant at the head of the pulse of the remote control signal from the demodulation section, and generates the pulse of the remote control signal. At the end, the remote control signal is integrated with a short time constant. The waveform shaping unit shapes the remote control signal integrated by the second integration circuit into a rectangular waveform based on whether the signal is larger than the reference level, and outputs the result as a remote control signal after the waveform correction. .

Therefore, even if the end of the pulse of the remote controller signal demodulated by the demodulation unit is later than the end of the original remote control signal, the second integration circuit starts the pulse of the remote control signal from the demodulation unit. Since the signal is integrated with a long time constant in the section, the pulse head of the remote control signal after the waveform correction is delayed from the head of the original remote control signal. On the other hand, the delay of the pulse end portion of the remote control signal after the waveform correction is small because it is integrated with a short time constant. As a result, by properly setting the time constant of the second integration circuit and the reference level, the pulse width of the remote control signal after the waveform correction can be made to match the pulse width of the original remote control signal. Therefore, even when the infrared carrier signal is supplied to the controlled device via the relay device, the error in the pulse width of the remote control signal is demodulated in the controlled device by configuring the relay device with the remote control signal receiving device of the present invention. The controlled device correctly extracts control information by a remote control signal demodulated from the infrared carrier signal, since the error can be tolerated.
It can operate reliably based on remote control by an infrared remote control.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an infrared remote control signal transmission / reception system including a transmission unit as an example of a remote control signal reception device according to the present invention.

FIG. 2 is a circuit diagram showing in detail a remote control signal waveform correction unit constituting the transmission unit of FIG. 1;

FIG. 3 is a waveform chart showing an operation of the infrared remote control signal transmission / reception system of FIG. 1;

FIG. 4 is a block diagram illustrating an infrared remote control signal transmission / reception system according to a second embodiment;

FIG. 5 is a circuit diagram showing in detail a remote control signal waveform correction unit constituting the second embodiment.

FIG. 6 is a block diagram showing a conventional infrared remote control signal transmission / reception system.

FIG. 7 is a waveform chart showing signals of respective units in the transmission system of FIG. 6;

FIG. 8 is a block diagram showing an example of a conventional infrared remote control signal transmission / reception system that does not perform demodulation and remodulation of an infrared carrier signal.

9 is a waveform chart showing the operation of the infrared remote control signal transmission / reception system of FIG.

[Explanation of symbols]

2 ... Infrared remote control signal transmission / reception system, 4 ... Resistance, 6 ... Integration circuit, 8 ... Waveform shaping unit, 10 ... First
, Second input terminal, 14 output terminal, 16 first comparator, 17 second comparator, 18 infrared remote control signal transmission / reception system, 100 infrared remote control, 102: determination level, 104: predetermined determination level, 106: infrared remote control signal transmission / reception system, 110: infrared remote control signal transmission / reception system, 200: transmission unit, 200A
...... Sending unit, 200B ... Sending unit, 201
…… Infrared light receiving unit, 202 …… Infrared carrier demodulation unit
203: remote control signal waveform correction unit, 203A: remote control signal waveform correction unit, 204: remote control signal modulation unit,
205: transmission unit, 206: waveform correction width setting unit, 30
0: communication line, 400: receiving unit, 400A
Receiving unit, 401: receiving unit, 402: remote control signal demodulating unit, 403: infrared carrier modulating unit, 404
...... Infrared light emitting section, 500 ... Controlled equipment, 501 ...
Infrared light receiving section, 502 ... Infrared carrier demodulating section, 50
3 ... operation control unit, R1 to R7 ... resistance, C1 ... capacitor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/26 H04B 9/00 Y 10/14 10/04 10/06 H04L 25/03 H04Q 9/00 301 311

Claims (7)

[Claims] A light receiving section for receiving an infrared carrier signal obtained by modulating an infrared pulse train with a remote control signal and converting the signal into an electric signal; an output signal of the light receiving section being integrated by an integrating circuit including a capacitor and a resistor; A demodulation unit that demodulates the remote control signal by shaping a waveform of the remote control signal, comprising: a waveform correction unit that changes a pulse width of the remote control signal demodulated by the demodulation unit. A second capacitor that integrates the remote control signal with a long time constant at the beginning of the pulse of the remote control signal from the demodulation unit and integrates the remote control signal with a short time constant at the end of the pulse of the remote control signal; And a second integrating circuit including a second resistor and the remote control signal integrated by the second integrating circuit. Waveform shaping into a rectangular wave based on whether heard or not, the result remote control signal receiving apparatus characterized by comprising a waveform shaping section for outputting a remote control signal after waveform corrected. 2. The circuit according to claim 1, wherein the second resistor comprises a third resistor and a fourth resistor, a series circuit of the second capacitor and the third resistor is connected between a power supply and a reference potential point, One end of a fourth resistor is connected to a common connection point between the second capacitor and the third resistor, and the other end of the fourth resistor is based on the magnitude of the remote control signal from the demodulation unit. The third state of the second capacitor, the open state or the second capacitor.
Is controlled so as to have the same potential as the terminal opposite to the resistance of
The remote control signal receiving device according to claim 1, wherein a resistance value of the third resistor is larger than a resistance value of the fourth resistor. 3. The first integration circuit according to claim 1, wherein the second integration circuit includes a first integration circuit and a second integration circuit.
A comparator that sets an output terminal to the same potential as a reference potential point or to an open state based on a comparison result of the voltages of the input terminals of the input terminal, wherein the remote control signal from the demodulation unit is input to the first input terminal, The remote control signal receiving device according to claim 2, wherein a reference voltage is applied to an input terminal of the second resistor, and the output terminal is connected to the other end of the fourth resistor. 4. The waveform shaping section includes a second comparator, and a first input terminal of the second comparator is connected to a common connection point between the second capacitor and the third resistor. 3. The remote control signal receiving device according to claim 2, wherein a reference voltage is applied to the second input terminal. 5. A voltage adjusting unit for applying a reference voltage to the second input terminal of the second comparator, wherein the reference voltage output from the voltage adjusting unit is variable. 5. The remote control signal receiving device according to 4. 6. The remote control signal receiving device according to claim 1, wherein said light receiving section receives an infrared carrier signal transmitted from an infrared remote control unit. 7. A transmission unit for modulating a carrier signal, which is an electric signal, with the remote control signal output from the waveform shaping unit and transmitting the modulated carrier signal to a communication line.
The remote control signal receiving device as described in the above.