JP2007158381A - Infrared ray communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared ray communication device capable of normally performing infrared ray communication even when an infrared ray receiving face directly receives the sunlight in its normal direction. <P>SOLUTION: The infrared ray communication device 10 comprising: a receiver side light receiving element 1; a transmitter side light emitting element 2; and a communication unit main body 3, uses the receiver side light receiving element 1 and the transmitter side light emitting element 2 whose infrared ray wavelength band ranges from 1,300 nm to 1,500 nm and that are InGaAs elements. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an infrared communication device, and more particularly, to an infrared communication device capable of performing communication without hindrance even outdoors under sunlight.

  In general, an infrared communication device is incorporated in a remote controller (hereinafter abbreviated as “remote controller”), a computer, a printer, another terminal device, a portable information device called PDA (Personal Digital Assistant), and the like, and transmits them. It is used as a communication means for exclusive use, exclusive use for reception or transmission / reception.

  In these conventional infrared communication apparatuses, a silicon element (hereinafter, abbreviated as “Si element”) having sensitivity in a wavelength region whose main wavelength is around 940 nm to 950 nm is used for the light emitting element and the light receiving element. This is because the environment in which the infrared communication device is used is mainly indoors, so that there is no disturbing light in the vicinity of 940 nm to 950 nm, and there is no influence on the communication. Light Emission Diode (hereinafter abbreviated as “LED”) is inexpensive.

  In the case of an Si element, as shown in FIG. 5, the emission spectrum has a main wavelength from 940 nm to 950 nm, and the relative sensitivity characteristic has a sensitivity peak in the wavelength region from 900 nm to 1000 nm as shown in FIG. Existing.

  However, it is known that a large amount of disturbance light from the sun exists in the vicinity of 940 nm to 950 nm in the spectrum of sunlight on the outdoor ground surface. For this reason, when infrared communication is performed outdoors using Si elements, communication is performed in the presence of a large amount of sunlight spectrum on the ground surface, so infrared communication information is buried in the infrared rays of sunlight. As a result, infrared communication cannot be performed satisfactorily.

  Examples of indoor infrared communication using LEDs other than Si elements include, for example, high-speed LEDs of gallium arsenide aluminum compound elements having different wavelengths and low-speed LEDs of gallium arsenide compound elements. And a high-speed signal generation unit and a low-speed signal generation unit that generate information signals that match the emission wavelength of the low-speed LED, and output of each information signal that matches the emission wavelength of each generated high-speed LED or low-speed LED By providing an information signal switching unit, it has been proposed to perform communication in accordance with the communication wavelength type of the other receiver (see Patent Document 1).

  In addition, the imaging unit having sensitivity in the optical wavelength region including the infrared region captures an image of a small region including the target external infrared device, and the result is subjected to image processing, and image data obtained by image processing by the position detection unit Based on the above, it is determined whether or not there is an external infrared device that detects an area that exceeds a certain amount of infrared light and outputs infrared light with a predetermined blinking pattern. When it is determined that the target external infrared device is present, it is also known that the position information presentation unit presents the position information of the target external infrared device to the user (see Patent Document 2).

  Furthermore, while the target infrared communication is being performed, the imaging unit is turned on, the malicious external infrared device is continuously monitored, the imaging result of the imaging unit is image-processed, and based on the image data obtained by this image processing, It is determined whether there is another external infrared device. If it is determined that another external infrared device is present, the infrared communication unit may be turned off immediately because it may be a malicious external infrared device. It is also known that the infrared communication is stopped by this, and that the infrared communication is stopped is reported to the user by display on the display unit of the mobile phone (see Patent Document 3).

JP-A-9-181673 Japanese Patent Publication No. 2004-112226 Japanese Patent Publication No. 2004-112227

  In the conventional infrared communication device, when performing infrared communication outdoors, the light emitting element part of the infrared communication device has a problem that it cannot communicate normally due to the influence of light including strong infrared rays of sunlight. . This is because infrared communication information is buried in infrared information of sunlight because a large amount of sunlight spectrum on the ground surface exists in the infrared wavelength region used for infrared communication. This tendency becomes remarkable particularly in the case of infrared communication outdoors under hot sun in the summer when the sunlight is strong.

  An object of the present invention is to provide an infrared communication device capable of normally performing infrared communication even when direct sunlight is radiated from the normal direction of the infrared light receiving surface as in the hot weather in summer. is there.

  In the present invention, in the infrared communication apparatus having the infrared light emitting element on the transmission side and the communication unit main body, the infrared light emitting element on the transmission side is configured using a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm.

  According to the present invention, in the infrared communication device having the receiving side infrared light receiving element and the communication unit main body, the receiving side infrared light receiving element is configured using a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm. .

  Further, according to the present invention, in the infrared communication device having the infrared light emitting element on the transmission side, the infrared light receiving element on the reception side, and the communication unit main body, the infrared light emitting element on the transmission side and the infrared light receiving element on the reception side have infrared wavelengths respectively. A light receiving and emitting element having a wavelength range of 1300 nm to 1500 nm is used.

  Preferably, an indium gallium arsenide element (hereinafter referred to as an “InGaAs element”) is used as a light emitting / receiving element having an infrared wavelength range of 1300 nm to 1500 nm.

  If an infrared communication device is configured as in the present invention, a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm that is hardly present on the outdoor ground surface is used. Even in the case of irradiation from the normal direction of the infrared light receiving surface, infrared communication can be performed without hindrance.

  When the infrared communication device of the present invention is composed of a light emitting / receiving element on the receiving side and a transmitting side and a communication unit main body, the light receiving / emitting element on the receiving side and the transmitting side has an infrared wavelength range of 1300 nm to 1500 nm. Is configured to perform infrared communication.

  An embodiment of the present invention will be described below using an infrared communication device 10 shown in FIG. The infrared communication device 10 includes a light receiving element 1 on the receiving side, a light emitting element 2 on the transmitting side, and a communication unit main body 3. The communication unit body 3 includes an A / D converter 4 that converts analog information of infrared communication into digital information, a receiving circuit 5 that extracts received information, and a communication processing unit 6 that processes received information.

  The infrared communication device 10 includes a transmission circuit 7 that converts transmission information generated by the communication processing unit 6 into digital information, and a D / A converter 8 that converts digital information into analog information. Information is transmitted from the element 2 by infrared rays.

  In the present invention, the light receiving and emitting elements 1 and 2 on the receiving side and the transmitting side use light receiving and emitting elements having an infrared wavelength range of 1300 nm to 1500 nm. For example, an InGaAs element can be used as a light emitting / receiving element having an infrared wavelength range of 1300 nm to 1500 nm.

  The relationship between the wavelength of the sunlight spectrum on the ground surface and the spectral irradiance is different between the clear sky of line A and the cloudy sky of line B as shown in the characteristic diagram of FIG. Exceeding this, the wavelength of sunlight is attenuated by the absorption spectrum by the atmosphere, and on the ground surface in fine weather, there is almost no wavelength of sunlight in the range W around 1300 nm to 1500 nm, and in cloudy weather On the ground surface, the wavelength of sunlight is only slightly present in the vicinity of 1500 nm. For this reason, in the infrared communication device 10 of the present invention, in order to perform infrared communication satisfactorily, a light emitting / receiving element having an infrared wavelength range of 1300 nm to 1500 nm is used.

  In the case of an InGaAs element which is an example of a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm, the relative spectral sensitivity has a peak from 1250 nm to around 1600 nm as indicated by a line G. Is significantly different from those having a peak of relative spectral sensitivity in the vicinity of 940 nm to 950 nm.

  Further, the emission spectrum of the InGaAs element is an emission spectrum having a main wavelength near 1450 nm as shown in FIG. 3, and the spectral absolute sensitivity characteristic of the InGaAs element is a sensitivity having a main wavelength of 1500 nm as shown in FIG. It shows a peak.

  Therefore, when the InGaAs element is used as a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm of the infrared communication device 10, stable infrared communication can be performed even under outdoor sunlight. In the case of using an InGaAs element, as a matter of course, the configuration of the communication unit main body 3 of the infrared communication apparatus 10 is also set to be communicable with this element.

  The InGaAs device has good sensitivity in the wavelength range of 1400 nm to 1500 nm, and the sunlight spectrum on the ground surface in this wavelength range has a remarkable absorption spectrum by the atmosphere as described above. In some cases, a slight presence is observed near 1500 nm, but the wavelength range from 1400 nm to 1450 nm hardly exists during both fine weather and cloudy weather.

  From this, when the InGaAs element is used as a light emitting element or a light receiving element of an infrared communication device, infrared communication outdoors under sunlight does not cause any problems as in the case of using an Si element, This can be done well even under hot weather in summer.

  The infrared communication device 10 having the configuration shown in FIG. 1 using a light emitting / receiving element having an infrared wavelength range of 1300 nm to 1500 nm, particularly an InGaAs element, is incorporated in a general computer and peripheral devices, portable information devices, etc. Can be used for two-way information communication.

  In addition, in the case of exclusive use for transmission such as a remote controller, each part on the light receiving side of the infrared communication device 10 is omitted. Conversely, in the case of a portable information device used exclusively for reception, each part on the light receiving side is omitted. And can be used for one-way information communication outdoors.

1 is a block diagram illustrating an infrared communication device according to an embodiment of the present invention. It is a characteristic view which shows the relationship between the wavelength of the sunlight spectrum and the spectral irradiance on the ground surface at the time of fine weather and cloudy weather, and the relative spectral sensitivity of the InGaAs element and the Si element. It is an emission spectrum figure of an InGaAs element. It is a spectral sensitivity characteristic figure of an InGaAs element. It is an emission spectrum figure of Si element. It is a spectral sensitivity characteristic figure of Si element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light receiving element, 2 ... Light emitting element, 3 ... Communication part main body, 4 ... A / D converter, 5 ... Reception circuit, 6 ... Communication processing part, 7 ... Transmission circuit, 8 ... D / A converter, 10 ... Infrared communication device.

Claims (4)

  An infrared communication apparatus having an infrared light emitting element on a transmission side and a communication unit main body, wherein the infrared light emitting element on the transmission side is configured using a light emitting element having an infrared wavelength range of 1300 nm to 1500 nm. apparatus.   An infrared communication device having an infrared light receiving element on a receiving side and a communication unit main body, wherein the infrared light receiving element on the receiving side is configured using a light receiving element having an infrared wavelength range of 1300 nm to 1500 nm. apparatus.   In the infrared communication device including the infrared light emitting element on the transmission side, the infrared light receiving element on the reception side, and the communication unit main body, the infrared light emitting element on the transmission side and the infrared light receiving element on the reception side each have an infrared wavelength range of 1300 nm to 1500 nm. An infrared communication device comprising: a light receiving and emitting element. 4. The infrared communication device according to claim 1, wherein the light receiving and emitting element having an infrared wavelength range of 1300 nm to 1500 nm is formed using an indium gallium arsenide element.

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