JP2005203937A - Infrared signal receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared signal receiving apparatus capable of receiving both remote control signals for household appliances and IrDA signals without imposing unnecessary burden on a CPU and requiring the setting of a specific keyword with a transmitting apparatus. <P>SOLUTION: An infrared ray receiving unit 1 converts an infrared signal into an electric signal, and a pulse interval measuring unit 21 identifies whether or not an infrared signal from the unit 1 is an IrDA signal, and a mask 23 controls the output of the electric signal to a poststage. The unit 1 receives the IrDA signal, and an IrDA signal receiving unit 2 outputs the electric signal without any change if the pulse interval measured by the unit 21 is not less than a predetermined threshold. A remote control signal is received, and if the pulse interval is less than a predetermined threshold, the unit 2 controls the mask unit 23 to mask a change in the electric signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an infrared signal receiving device, and more particularly to an infrared signal receiving device having a function of enabling reception of both signals from a remote control for home appliances and a signal based on an IrDA standard.

  Infrared remote control is used to operate home appliances such as TV and audio from a distance. Remote control that modulates infrared rays and transfers data is widely used for these. On the other hand, among portable information devices such as portable personal computers and mobile phones, those having a function of exchanging data between devices at short distances using infrared rays have become widespread. This communication is performed in a format based on a standard established by the industry standardization organization IrDA.

  The wavelength of the carrier wave used in the infrared remote control is mainly 900 to 980 nm, and the wavelength of the carrier wave for IrDA communication is 850 to 900 nm. A subcarrier is used for infrared remote control but not for IrDA communication.

  When equipped with an IrDA communication function for devices that can be operated by infrared remote control, the high speed and bidirectional communication that are the features of IrDA communication can be used to enable various forms of usage, not just remote control. It becomes.

As an infrared signal receiving device capable of receiving both infrared remote control signals and IrDA communication infrared signals, a remote control signal demodulator and an IrDA demodulator are connected in parallel and operated. Therefore, the output of the IrDA light-receiving photodiode also changes with respect to the infrared of the remote controller, and the signal is passed to the IrDA demodulator at the subsequent stage. For this reason, since processing that is originally required when an IrDA signal is received is also performed when a remote control signal is received, there is a problem that an extra load is applied to the CPU, and an infrared signal receiving apparatus corresponding to this problem. For example, there is a device described in Patent Document 1. In a conventional infrared signal receiving apparatus, a remote control signal demodulator and an IrDA demodulator are switched by a switch so that any infrared signal can be received without placing an extra load on the CPU.
Japanese Patent Laid-Open No. 11-127115 (page 3-4, FIG. 1)

  However, in the conventional infrared signal receiving apparatus, when a specific keyword is received in advance with a remote control signal (second infrared signal) with the apparatus that transmits the infrared signal, the switch is set to the IrDA signal (first signal). Therefore, there is a problem that the IrDA signal cannot be received unless the user operates the device that transmits the infrared signal according to the agreement.

The present invention has been made in order to solve the conventional problems. A remote control signal (second infrared signal) is transmitted in advance to a device that transmits an infrared signal without imposing an extra load on the CPU. When a specific keyword is received, it is not necessary to switch the switch to a demodulator that demodulates an IrDA signal (first infrared signal), and the user operates the device that transmits the infrared signal. It is an object of the present invention to provide an infrared signal receiving device that can receive signals from both a remote control for home appliances and an IrDA signal protocol without necessity.

  An infrared signal receiving device according to the present invention comprises an infrared light receiving means for converting a first infrared signal into a first electrical signal when receiving the first infrared signal, and converting into a second electrical signal when receiving the second infrared signal. And an electric signal identifying means for identifying whether the electric signal converted by the infrared light receiving means is the first electric signal, and a signal passage control means for controlling the passage of the signal from the infrared light receiving means. However, when it is identified as the first electric signal, the signal passage control means permits the passage of the signal.

  With this configuration, the second infrared signal does not pass through the signal passing control means, and the infrared signal is transmitted without applying an extra load to the subsequent circuit operation such as the CPU that processes the first infrared signal. When a specific keyword is received in advance with a remote controller signal (second infrared signal), the switch must be switched to a demodulator that demodulates the IrDA signal (first infrared signal). In addition, it is possible to receive signals of both the first infrared signal and the second infrared signal without requiring the user to operate an apparatus for transmitting the infrared signal.

  Further, the infrared signal receiving device of the present invention has a configuration in which the electrical signal identifying means identifies the first electrical signal by measuring the pulse interval of the electrical signal converted by the infrared light receiving means. With this configuration, the first electric signal and the second electric signal can be easily distinguished.

  In the infrared signal receiving device of the present invention, the first infrared signal includes a first signal format at the start of communication with another device and a second signal format after establishing communication with the other device. The infrared light receiving means has at least two signal formats, and the infrared light receiving means converts the infrared signal of the first signal format into a first electric signal and the infrared signal of the second signal format into a third electric signal. Have. With this configuration, it is possible to cope with the first infrared signal having a different signal format after the communication start stage and communication establishment.

  The infrared signal receiving apparatus according to the present invention includes a format switching unit that selects a first signal format as an initial value, and an electric signal from the signal passage control unit when the format switching unit selects the first signal format. Signal switching means for permitting passage of signals and permitting passage of electrical signals from the infrared light receiving means except when the format switching means selects the first signal format, and the format switching means has an initial value. When the first signal format is selected, the mode switching unit is instructed to switch the format when it is confirmed that the first electrical signal passes through the signal switching unit and communication with other devices is established. And a mode switching instruction means.

  With this configuration, in receiving the first infrared signal, after establishing communication with another device using the infrared signal of the first communication mode, for example, it has a communication speed similar to that of the second infrared signal having a high communication speed. The signal can be received by switching to the second signal format.

  The infrared signal receiving device of the present invention has a configuration in which the first infrared signal is a signal compliant with the IrDA standard. With this configuration, an infrared signal conforming to the IrDA standard can be received as the first infrared signal. On the other hand, when an infrared signal other than IrDA is received, changes in the electrical signal can be masked.

Furthermore, the infrared signal receiving device of the present invention has a configuration in which the second infrared signal is an infrared remote control signal. With this configuration, an IrDA-compliant infrared signal can be received as the first infrared signal. On the other hand, when an infrared remote control signal as the second infrared signal is received, changes in the electrical signal are masked. be able to.

  The present invention includes an infrared light receiving means that converts a first infrared signal into a first electrical signal when the first infrared signal is received, and a second electrical signal when the second infrared signal is received, and an infrared light receiving means. An electrical signal identifying means for identifying whether the converted electrical signal is the first electrical signal; and a signal passage control means for controlling the passage of the signal from the infrared light receiving means. Since the signal passage control means permits the passage of the signal when identified as an electrical signal, the second infrared signal processes the first infrared signal without passing through the signal passage control means. When a specific keyword is received with a remote control signal (second infrared signal) in advance with a device that transmits an infrared signal without imposing an extra load on the subsequent circuit operation, such as a CPU It is not necessary to switch the switch to a demodulator that demodulates an IrDA signal (first infrared signal), and the first infrared signal does not require the user to operate the device that transmits the infrared signal. It is possible to provide an infrared signal receiving apparatus having an effect of being able to receive both protocol signals of the second infrared signal and the second infrared signal.

  Hereinafter, an infrared signal receiver according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an internal circuit configuration of an infrared signal receiving apparatus according to an embodiment of the present invention.

  In FIG. 1, an infrared signal receiving apparatus includes an infrared light receiving unit 1 configured by a photodiode or the like that converts an infrared signal into an electrical signal, an IrDA signal receiving unit 2 that receives a signal compliant with the IrDA standard, and an infrared light receiving unit 1. A remote control signal receiving unit 3 that receives a remote control signal that is a second infrared signal received and converted into an electrical signal, an IrDA signal transmission unit 4 that generates an IrDA-compliant electrical signal to be transmitted to another device, and IrDA An infrared light emitting unit 5 including a light emitting LED that converts an electrical signal from the signal transmission unit 4 into an infrared signal, a remote control data output unit 6 that outputs remote control data from the remote control signal received by the remote control signal receiving unit 3, An IrDA data output unit 7 for outputting a signal received by the IrDA signal receiving unit 2, a microcomputer for transmitting an IrDA signal, and I It includes a IrDA data input unit 8, which is the interface between the DA signal transmitter 4.

  The infrared light receiving unit 1 is shared by the remote control signal reception and the IrDA signal reception. However, a configuration in which the infrared light reception unit 1 is dedicated to IrDA and the remote control signal reception unit 3 is an integrated circuit with a light reception function is also possible. . The reception data demodulated by the remote control signal receiving unit 3 is transmitted to the remote control data output unit 6 and serves as an interface with a microcomputer not shown. The received data demodulated by the IrDA signal receiving unit 2 is transmitted to the IrDA data output unit 7 and serves as an interface with the microcomputer.

  The IrDA signal receiving unit 2 includes a pulse interval measuring unit 21 that measures a pulse interval of a signal received by the infrared light receiving unit 1 and converted into an electric signal, a delay unit 22 that delays the received electric signal for a predetermined time, and a pulse interval measurement. Based on the measurement result of the unit 21, the mask unit 23 that can mask the change of the electrical signal output from the delay unit 22, and either the output from the mask unit 23 or the direct output from the infrared light receiving unit 1 A selector 24 that is selected by a signal from the mode switching unit 25 and a demodulation unit 26 that demodulates the IrDA signal are provided. Here, the delay unit 22 is for compensating the time required for the measurement by the pulse interval measurement unit 21.

  The operation of the infrared signal receiving apparatus having the above configuration will be described below.

  First, when receiving the IrDA signal, the infrared light receiving unit 1 converts the infrared signal into an electrical signal and outputs the electrical signal to the IrDA signal receiving unit 2 and the remote control signal receiving unit 3. At the start of IrDA communication, the transfer rate is 9.6 Kbps based on the standard. FIG. 2 is a signal waveform diagram when the IrDA signal is received by the infrared signal receiver according to the embodiment of the present invention. The format of the infrared signal is RZI (Return to Zero) as shown in FIG. 2A, and there is radiation of 3/16 of the data period when data 0 is transmitted.

  The infrared light receiving unit 1 outputs 1 when no radiation is detected, and outputs 0 having a certain width when radiation is detected. Since the remote control signal receiving unit 3 has a known band limiting filter inside, a signal with a transfer rate of 9.6 Kbps is blocked and the output remains at 1.

  On the other hand, in the IrDA signal receiving unit 2, the pulse interval measuring unit 21 measures the pulse interval of the electric signal shown in FIG. Here, an integer multiple of the period (about 104 microseconds) is detected as the pulse interval. At this time, the pulse interval measurement unit 21 outputs the output of the delay unit 22 to the selector 24 as it is because the measured pulse interval is equal to or greater than a predetermined threshold value. Here, the threshold value is set to an optimum value for distinguishing between 9.6 Kbps data and remote control data, for example, 60 microseconds.

  The selector 24 selects either the output of the mask unit 23 or the output of the infrared light receiving unit 1 under the control of the mode switching unit 25 and outputs it to the demodulating unit 26. Here, the mode switching unit 25 selects the output of the mask unit 23 as an initial value. The demodulator 26 demodulates the input data into an NRZ (Non Return to Zero) signal, as shown in FIG. The microcomputer reads data from the IrDA data output unit 7.

  In IrDA, it is an option that the communication is shifted to a higher transfer rate by negotiation. When the microcomputer recognizes the shift to the high transfer rate, the microcomputer controls the mode switching unit 25 and outputs the direct output from the infrared light receiving unit 1 from the selector 24 to the demodulation unit 26.

  As shown in FIG. 3A, the remote controller that transmits the second infrared signal outputs a subcarrier while the control signal of the remote control is high, and while the control signal is low, A carrier wave is not output. FIG. 3 is a signal waveform diagram at the time of remote control signal reception of the infrared signal reception device according to the embodiment of the present invention. In this example, 38 kHz is used as the modulation frequency, and FIG. 3A shows a control signal on the remote control side.

  The infrared light receiving unit 1 that has received the optical input from the remote controller shown in FIG. 3B outputs a pulse with a frequency of 38 kHz as shown in FIG. The remote control receiving unit 3 detects a 38 kHz modulation signal and outputs a detection output to the remote control data output unit 6. On the other hand, in the IrDA signal receiving unit 2, the pulse interval measuring unit 21 measures the pulse interval of the electric signal.

  Here, the period of the subcarrier (about 26.3 microseconds) is detected as the pulse interval. At this time, the pulse interval measurement unit 21 determines that the measured pulse interval is less than a predetermined threshold value, for example, 60 microseconds, so that the mask unit 23 masks the output of the delay unit 22 and outputs it to the selector 24. To do. Here, since the mode switching unit 25 selects the output of the mask unit 23 as an initial value, no data is output from the demodulation unit 26 as shown in FIG.

  According to such an infrared signal receiving device of an embodiment of the present invention, the IrDA signal receiving unit includes a pulse interval measuring unit, a mask unit, a mode switching unit, and a selector, and the infrared light receiving unit receives light. By measuring the pulse interval of the converted electrical signal and switching the mask portion, the microcomputer processing IrDA data is erroneously recognized as receiving IrDA data by the remote control signal, and no unnecessary operation is performed. .

  In addition, when a specific keyword is received with a remote control signal in advance with a device that transmits an infrared signal, there is no need to switch the switch to a demodulator that demodulates an IrDA signal. Can receive both IrDA signals and remote control signal signals without having to operate a device that transmits infrared signals.

  In the present embodiment, the first infrared signal is an IrDA standard-compliant signal and the second infrared signal is an infrared remote control signal. However, the present invention is not limited to this, A combination with an infrared signal specification used for various game machines, an infrared communication specification used for a karaoke apparatus, an infrared communication specification used for a PDA, or the like may be used.

  Further, although the electric signal identifying means has been described in the case of measuring the pulse interval of the electric signal, the present invention is not limited to this, and the change of the pulse interval, the phase of the pulse, and the signal superimposed on the pulse are not limited thereto. The infrared ray may be a near infrared ray. Moreover, although the case where the threshold value in the pulse interval measurement unit is 60 microseconds has been described, the present invention is not limited to this, and any value can be used as long as the first electric signal and the second electric signal can be identified.

  As described above, the infrared signal receiving apparatus according to the present invention places an extra load on the subsequent circuit operation such as the CPU that processes the first infrared signal without the second infrared signal passing through the signal passing control means. Without a switch, when a specific keyword is received in advance with a remote control signal (second infrared signal) with a device that transmits an infrared signal, the switch is set to IrDA signal (first infrared signal). There is no need to switch to a demodulator to demodulate, and there is no need for the user to operate the device that transmits the infrared signal, and the signals of both the first infrared signal and the second infrared signal are transmitted. It has the effect of being able to receive, and can receive signals of both the signal from the remote control for home appliances and the signal compliant with the IrDA standard. It is useful as an infrared signal receiver or the like having a function.

The block diagram which shows the internal circuit structure of the infrared communication receiver of one embodiment of this invention Signal waveform diagram at the time of IrDA signal reception of the infrared communication receiver according to the embodiment Signal waveform diagram at the time of remote control signal reception of the infrared communication receiver according to the embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Infrared light-receiving part 2 IrDA signal receiving part 3 Remote control signal receiving part 4 IrDA signal transmission part 5 Infrared light emission part 6 Remote control data output part 7 IrDA data output part 8 IrDA data input part 21 Pulse interval measurement part 22 Delay part 23 Mask part 24 Selector 25 Mode switching unit 26 Demodulating unit

Claims (6)

Infrared light receiving means for converting the first infrared signal to the first electric signal when receiving the first infrared signal, and the second electric signal for receiving the second infrared signal, and the electric power converted by the infrared light receiving means. An electrical signal identifying means for identifying whether the signal is the first electrical signal; and a signal passing control means for controlling the passage of the signal from the infrared light receiving means, wherein the electrical signal identifying means comprises the first electrical signal identifying means. An infrared signal receiving apparatus, wherein the signal passage control means permits passage of a signal when it is identified as an electrical signal. 2. The infrared signal receiving apparatus according to claim 1, wherein the electrical signal identifying means identifies the first electrical signal by measuring a pulse interval of the electrical signal converted by the infrared light receiving means. The first infrared signal has at least two signal formats: a first signal format at the start of communication with another device and a second signal format after establishment of communication with the other device; The infrared light receiving means converts the infrared signal of the first signal format into the first electrical signal and converts the infrared signal of the second signal format into a third electrical signal. Or the infrared signal receiver of Claim 2. A mode switching means for selecting the first signal format as an initial value, and allowing passage of an electrical signal from the signal passing control means when the format switching means has selected the first signal format, Signal switching means for permitting passage of an electrical signal from the infrared light receiving means except when the style switching means selects the first signal style, and the style switching means has the first value as the initial value. When it is confirmed that the first electrical signal passes through the signal switching means and communication with the other device is established when one signal format is selected, the format switching means switches the format. The infrared signal receiving apparatus according to claim 3, further comprising: mode switching instruction means for instructing The infrared signal receiver according to any one of claims 1 to 4, wherein the first infrared signal is an IrDA standard-compliant signal. 6. The infrared signal receiving apparatus according to claim 5, wherein the second infrared signal is an infrared remote control signal.

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