JP2000036791A - Transmission equipment, equipment and method for communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide communication equipment for performing normal communication, with low power consumption. SOLUTION: An ultrasonic sensor 60 transmits ultrasonic waves to infrared communication equipment 700, converts the reflected wave to voltage, and outputs it to a communication distance circuit 4. The communication distance circuit 4 converts the inputted voltage to a communication distance and outputs the information on the communication distance to a CPU 31. The CPU 31 compares the inputted information with the data of a communication distance and a resistance value, corresponding to the communication distance stored in a resistance value data memory 5 and instructs the setting of a resistance value to a light emitting LED control circuit 100. According to the instruction of the CPU 31, the light emitting LED control circuit 100 sets the resistance value of a potentiometer 50 and changes a current flowing through an LED transmission/reception circuit 400 into a value which corresponds to the communication distance. The LED transmission/reception circuit 400 emits infrared light with a current, corresponding to the communication distance and transmits information to infrared communication equipment 700. The LED transmission/reception circuit 500 receives information with infrared light corresponding to the communication distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transmission device, a communication device, and a communication method using electromagnetic waves, and more particularly to a transmission device, a communication device, and a communication method that enable stable communication using infrared rays.

[0002]

2. Description of the Related Art Communication technology using infrared rays is used for remote control of televisions and audios and portable terminal devices such as wireless devices.

In infrared communication, there are a transmission device that transmits data using infrared light, and a reception device that receives data from the transmission device. The transmitting device includes a light emitting LED that emits infrared light, and the receiving device includes a photodiode that receives infrared light from the transmitting device.

When a photodiode of a receiving device receives infrared light, a photocurrent corresponding to the amount of incident light flows through the photodiode, and a voltage applied across a load resistor connected in series with the photodiode is output as an output voltage. Is done.

The communication distance of such infrared communication is Ir
da (Infrared Data Association) standard, 0cm
Is set to 100 cm. Therefore, the light emitting LED of the transmitting device must emit infrared light that can be received by the photodiode of the receiving device 100 cm away. However, when the communication distance is reduced, if the current flowing through the light emitting LED of the transmitting device is set to a current value corresponding to the maximum communication distance (100 cm) of the Irda standard, the amount of light incident on the photodiode of the receiving device will be reduced. Greatly increase. Due to this large incident light amount, the pulse waveform of the output voltage of the photodiode is distorted (the pulse width is widened), and there is a problem that information cannot be normally received.

[0006] Such a distortion of the pulse waveform when the communication distance is short can be solved by reducing the resistance value of the load resistor connected in series to the photodiode of the receiving device. However, when the resistance value of the load resistor is set to be small, the communication distance becomes the maximum communication distance (100
cm), the photocurrent flowing through the photodiode of the receiver decreases. Therefore, the output voltage is reduced, and the receiving sensitivity of the receiving device is deteriorated.

A technique for solving such a problem is disclosed in JP-A-6-224855.

In the device equipped with this technology, as shown in FIG. 5, nine LEDs for transmitting infrared light are connected in series to the transmitting device, and when the FET T1 is turned on, the LED is connected to a 28V power supply. And emits infrared light. F
The on / off state of the ETT1 is controlled by the output of the inverter N1. For example, a pulse signal subjected to PPM modulation (pulse position modulation) is applied to the inverter N1. In that case, the LED emits PPM modulated infrared light. The infrared light transmitted from the LED is transmitted to the photodiode P. of the light receiving device. D, and a photocurrent corresponding to the amount of incident light is applied to the photodiode P.D. Flow to D. This photocurrent causes the photodiode P. The voltage generated at both ends of the load resistor 2 connected in series to D is output as an output voltage via the output terminal OUT.

[0009] The LED and the photodiode P. D, and the distance R from the photodiode P.D decreases. D
The amount of infrared light incident on the light source increases. At this time, the photodiode P. D is supplied to the photodiode P.D. A resistor 1 connected in series with D
To detect. The pulse width of the output voltage is prevented from expanding by changing the value of the load resistor 2 according to the magnitude of the detected average current.

[0010]

Problems to be Solved by the Invention
In the technique disclosed in Japanese Patent Laid-Open Publication No. 5 (1999) -2005, control is performed so that information can be accurately received in a receiving device. Therefore, in the transmitting device, the maximum communication distance of Irda standard (100 cm)
However, the operating current of the light emitting LED of the transmitting device must be set so that a correct output signal can be obtained in the light receiving device.

In such a setting of the operating current, when the communication distance is short, a current more than necessary flows to the light emitting LED, and there is a problem that power is wasted.

[0012] In addition, in the case of operating with a battery, there is a problem that the consumption time of the battery is shortened by flowing an excessive current.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a highly reliable communication device and a communication method capable of stably performing normal communication with small power consumption.

[0014]

In order to solve the above-mentioned problems, a transmitting apparatus according to a first aspect of the present invention is a transmitting apparatus for transmitting information using electromagnetic waves, and a receiving apparatus for receiving information. Distance measuring means for measuring the distance to the device, transmitting means for transmitting information to the receiving device using electromagnetic waves, and, according to the measurement result of the distance measuring means, the intensity of the electromagnetic waves transmitted by the transmitting means. And control means for controlling.

According to the present invention, the transmitting device can determine the distance to the external receiving device, and can transmit information at an electromagnetic wave intensity corresponding to the distance. Therefore, the transmitting device can efficiently consume power. Further, since the information can be transmitted at an intensity corresponding to the communication distance, the receiving device can receive the information stably and accurately, and the reliability is improved.

The control means stores a distance to the receiving device and information for changing the intensity of the electromagnetic wave transmitted by the transmitting means to an intensity corresponding to the distance, and uses the information to transmit the information. The intensity of the electromagnetic wave transmitted by the means may be controlled.

[0017] The distance measuring means may measure the distance using an ultrasonic wave.

The transmitting means may use infrared rays as electromagnetic waves.

[0019] The distance measuring means is installed close to the transmitting means.

The transmitting means has directivity, and the distance measuring means has the same directivity as that of the transmitting means.

A communication device according to a second aspect of the present invention comprises:
A means for measuring a distance to an external device for receiving information; a transmitting device for transmitting information at an electromagnetic wave intensity corresponding to the measured distance; and a receiving device for receiving information from a transmitting device existing outside. And an apparatus.

According to the present invention, the communication device can transmit information with the intensity of the electromagnetic wave according to the distance to the external receiving device. Therefore, the receiving device can receive information stably and accurately, and reliability is improved.

The transmitting device stores a distance to the external device and information for changing the intensity of an electromagnetic wave transmitted by the transmitting device to an intensity corresponding to the distance, and uses the information to perform the transmission. The intensity of the electromagnetic wave transmitted by the device may be changed.

[0024] The transmitting device may measure the distance using an ultrasonic wave.

[0025] The transmitting device may use infrared rays as electromagnetic waves.

A communication method according to a third aspect of the present invention comprises:
A measuring step of measuring a distance between a transmitting apparatus that transmits information and a receiving apparatus that receives the information, and a transmitting step in which the transmitting apparatus transmits information with an electromagnetic wave having an intensity corresponding to the measurement result of the measuring step. It is characterized by having.

According to the present invention, the transmitting device can transmit information with the intensity of the electromagnetic wave according to the distance to the external receiving device. Therefore, the receiving device can receive information stably and accurately, and the reliability is improved.

[0028] The measuring step may include a step of measuring a distance using an ultrasonic wave.

[0029] The transmitting step may include a step in which the transmitting apparatus transmits information by infrared rays as electromagnetic waves.

[0030]

Next, an infrared communication device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a circuit configuration of the infrared communication device.

This infrared communication device is capable of transmitting and receiving information. Here, transmission of information from infrared communication device 600 to infrared communication device 700 will be described.

The infrared communication device 600 and the infrared communication device 7
00 is actually the same configuration, but in FIG. 1, in the infrared communication device 700, components that are not necessary for the information receiving operation are omitted.

The infrared communication apparatus 600 includes a transmission / reception data memory 3, a communication distance circuit 4, and a resistance value data memory 5.
, An input unit 11 and a CPU (Central Processing Uni
t; central processing unit) 31, a potentiometer (resistance) 50, an ultrasonic sensor 60, a light emitting LED control circuit 100, an IR communication circuit 200, and an LED transmitting / receiving circuit 4.
00.

The transmission / reception data memory 3 comprises a hard disk, a floppy disk, a CD-ROM, or the like, and stores data to be transmitted and received data.

The input unit 11 is composed of a keyboard and the like, and inputs an instruction for transmitting data to the infrared communication device 700.

The ultrasonic sensor 60 includes an infrared communication device 70
An ultrasonic wave is transmitted toward zero, and the reflected wave is received. Then, the ultrasonic sensor 60 converts the received reflected wave into a voltage and outputs the voltage to the communication distance circuit 4. The ultrasonic sensor 60 uses a reflection-type detection method, and is provided with two transmitters that transmit ultrasonic waves and two receivers that receive the reflected waves. In addition, the ultrasonic sensor 60
Since the distance is measured in order to make the amount of light received by the photodiode of the infrared communication device 700 that receives infrared light an appropriate amount, it is installed in proximity to the light emitting LED of the infrared communication device 600 that emits infrared light. There must be. The directivity of the ultrasonic sensor 60 is determined by Irda (Infrared Data).
It is desirable that the value is approximately the same as the standard (within 30 °) of the Association.

The communication distance circuit 4 outputs the voltage from the ultrasonic sensor 60 to the infrared communication device 600 and the infrared communication device 70.
0 and the information about the communication distance is converted to CP.
Output to U31.

The memory 5 associates the distance between the infrared communication device 600 and the infrared communication device 700 with the resistance value,
It is stored as data. This resistance value is for setting the resistance value of the potentiometer 50 to make the current flowing through the LED transmitting / receiving circuit 400 a value corresponding to the communication distance.

CPU 31 controls the entire infrared communication device 600. Detailed functions of the CPU 31 will be described later in the description of the operation.

The light emitting LED control circuit 100 includes a CPU 31
, The resistance value of the potentiometer 50 is set, and the current flowing through the LED transmitting / receiving circuit 400 is changed. This resistance value is determined by data stored in the memory 5. Then, the light emitting LED control circuit 10
0 notifies the CPU 31 that the setting of the resistance value of the potentiometer 50 has been completed.

The potentiometer 50 is a variable resistor, and its resistance is set by the light emitting LED control circuit 100.

The IR communication circuit 200 sends out transmission data to the LED transmission / reception circuit 400 in accordance with an instruction from the CPU 31.

The LED transmitting / receiving circuit 400 includes a light emitting LED, and according to transmission data from the IR communication circuit 200,
The light emitting LED emits infrared light, and the data is transmitted to the infrared communication device 700. At this time, the LED transmitting / receiving circuit 4
The current flowing through 00 has a magnitude corresponding to the communication distance by setting the resistance value of the potentiometer 50 from the data stored in the memory 5.

The functions of the components of the infrared communication device 700 related to the information receiving operation will be described.

LED transmitting / receiving circuit 500 receives data transmitted from infrared communication device 600. Specifically, the LED transmitting / receiving circuit 500 includes a photodiode, and receives infrared light from the infrared communication device 600 with the photodiode. The infrared light incident on the photodiode is converted into a current and output to the IR communication circuit 300. At this time, the amount of infrared light received by the photodiode is determined by the LED transmitting / receiving circuit 400 of the infrared communication device 600.
Is set to a value corresponding to the communication distance, the current is always an appropriate amount.

The IR communication circuit 300 converts the data received by the LED transmitting / receiving circuit 500 so as to conform to the specifications of the device, and outputs the data to the CPU 32.

CPU 32 controls infrared communication device 700 as a whole based on data from IR communication circuit 300.

Next, the operation of the infrared communication apparatus having such a configuration will be described.

The operations performed by the components of the infrared communication device 600 described below are performed under the control of the CPU 31.

When starting infrared communication, an instruction for transmitting data to the infrared communication device 700 is input from the input unit 11 of the infrared communication device 600 to the CPU 31.

The ultrasonic sensor 60 includes an infrared communication device 70
The distance between the light emitting LED of the infrared communication device 600 and the photodiode of the infrared communication device 700 is measured in order to make the amount of infrared light received by the photodiode 0 appropriate.

The communication distance circuit 4 converts the voltage from the ultrasonic sensor 60 into a distance, and outputs information on the distance to the CPU.
31.

The CPU 31 compares the information from the communication distance circuit 4 with the data of the communication distance stored in the memory 5 in advance, and extracts the data of the resistance value corresponding to the communication distance. Then, the CPU 31 sends the information on the extracted resistance value to the light-emitting LED control circuit 100 and outputs the information to the potentiometer 5.
Notification is made as setting data of a resistance value of 0.

The light emitting LED control circuit 100 outputs a control signal for changing the resistance value to the potentiometer 50 according to the setting data notified by the CPU 3. Then, the light emitting LED control circuit 100
Is notified that the setting of the resistance value of the potentiometer 50 has been completed.

The potentiometer 50 changes the resistance value according to a control signal from the light emitting LED control circuit 100. As a result, an operating current corresponding to the communication distance flows through the LED transmitting / receiving circuit 400.

The CPU 31 includes a light emitting LED control circuit 100
In order to start the infrared communication, the transmission data is extracted from the transmission / reception data memory 3 and the transmission data is output to the IR communication circuit 200.

The IR communication circuit 200 converts the transmission data output from the CPU 31 into data conforming to the Irda standard, and outputs the data to the LED transmission / reception circuit 400.

The LED transmitting / receiving circuit 400 emits infrared light according to the data from the IR communication circuit 200 and transmits the data to the infrared communication device 700.

In infrared communication device 700, LED transmission / reception circuit 500 receives data by infrared light from infrared communication device 600 and sends the data to IR communication circuit 300.

The IR communication circuit 300 converts the data from the LED transmission / reception circuit 500 into data conforming to the specifications of the infrared communication device 700, and sends the data to the CPU 32.

The CPU 32 controls the infrared communication device according to the data from the IR communication circuit 300.

Next, when transmitting and receiving data, the IR communication circuits 200 and 300 and the LED transmission and reception circuits 400 and 5 are used.
The operation of 00 will be described in detail.

FIG. 2 shows a circuit configuration of the LED transmitting / receiving circuit 400 constituting the infrared communication device 600 and the LED transmitting / receiving circuit 500 constituting the infrared communication device 700.

The LED transmitting / receiving circuits 400 and 500 are connected to the IR communication circuits 200 and 300, respectively.

Further, the IR communication circuit 200 and the IR communication circuit 300, the LED transmitting / receiving circuit 400 and the LED transmitting / receiving circuit 5
00 has the same structure and can transmit and receive data.

The IR communication circuits 200 and 300 provide an I / O interface for parallel-to-serial conversion and serial-to-parallel conversion of communication data, and Irda for serial data.
And a circuit for encoding or decoding data conforming to the standard.

Each of the LED transmitting and receiving circuits 400 and 500 includes a light emitting LED 6, a transmission driver 7, a photodiode (PD) 8, and a receiver (REC) 9.

In the infrared communication apparatus 600, the IR communication circuit 200 converts the parallel data sent from the CPU 31 into serial data, encodes the data into Irda standard data, and sends the data to the LED transmitting / receiving circuit 400 as transmission data (TXD). .

In the LED transmitting / receiving circuit 400, the transmitting driver 7 controls the current flowing through the light emitting LED 6 according to the transmission data (TXD) received from the IR transmitting / receiving circuit 200, and causes the light emitting LED 6 to emit light. At this time, the current flowing through the light-emitting LED 6 is set by the resistance value of the potentiometer 50, and the light-emitting LED 6 emits infrared light of a light amount suitable for the photodiode 8 of the infrared communication device 700 to receive light.

On the other hand, in the infrared communication device 700, the LED
The photodiode 8 of the transmitting / receiving circuit 500 receives the infrared light from the infrared communication device 600, converts the infrared light into a current, and outputs the current to the receiver 9.

The receiver 9 controls the current from the photodiode 8 and sends the received data (RX
D).

The IR transmitting / receiving circuit 300 includes a receiver REC
9 is decoded, the serial data is converted into parallel data, and the decoded data is transmitted to the CPU 32.

Next, the light emission LE of the LED transmitting / receiving circuit 400
Control of the current flowing through D6 will be described.

FIG. 3 shows the internal configuration of the potentiometer 50.

The potentiometer 50 is connected to the decoder 10.
, A transistor array, and a resistor array.

The decoder 10 includes a light emitting LED control circuit 10
On / off of the transistors in the transistor array is controlled by a control signal from 0.

The number of resistors in the resistor array that acts on the circuit changes depending on which transistor in the transistor array is turned on. In this embodiment, the resistance value can be changed in 1 to 32 stages by turning on and off the transistor. The resistance values of the 32 levels are associated with the communication distance and stored in the memory 5 as data.

When transmitting information, the CPU 31 compares the distance obtained by the communication distance circuit 4 with the data in the memory 5 and sends out information on the resistance value corresponding to the distance to the light emitting LED control circuit 100. .

The light emitting LED control circuit 100 controls the potentiometer 50 based on the information of the resistance value from the CPU 3.
The control signal is sent to the decoder 10 of FIG. When the communication distance is short, the amount of infrared light from the infrared communication device 600 must be small. A control signal to increase the value is transmitted. On the other hand, when the communication distance is long, the amount of infrared light from the infrared communication device 600 must be large.
The light emitting LED control circuit 100 includes a potentiometer 50
A control signal for reducing the resistance value of is transmitted.

The decoder 10 includes a light emitting LED control circuit 10
The control signal from 0 is decoded to turn on one transistor in the transistor array. This is LED
A resistor for flowing an appropriate current to the light emitting LED of the transmitting / receiving circuit 400 is set.

FIG. 4 shows the operating current flowing through the light emitting LED with respect to the communication distance.

The light emitting LED conforming to the Irda standard is:
In each case, the operating current (light emitting LED current I
cd) increases as the distance (R) increases. That is,
If the distance (R) is small, the current (Ic) flowing through the light emitting LED
By setting d) to a value corresponding to the distance, it is possible to transmit information to an external receiving device without causing unnecessary current to flow through the light emitting LED.

As described above, infrared communication device 600
In, the operating current of the light emitting LED 6 is controlled to a value corresponding to the communication distance, and the information is transmitted at the luminous intensity of the infrared light corresponding to the communication distance. Therefore, in the infrared communication device 700,
The photodiode 8 always receives an appropriate amount of infrared light and can receive information stably and accurately.

The ultrasonic sensor 60 described above may be replaced with an optical sensor using light instead of ultrasonic waves.

When the infrared communication device 700 is a small device, the infrared communication device 70
Since there is a case where 0 cannot be recognized, it is necessary to shorten the distance so that the ultrasonic sensor can recognize even a small infrared communication device.

In the above embodiment, the infrared communication device 60
The CPU 31 of 0 compares the distance obtained by the communication distance circuit 4 with data in the memory 5 and sets a resistance value corresponding to the distance. At this time, the communication distance circuit 4 counts the communication distance. The notification may be made to the CPU 31 in stages.

The infrared communication device 600 has a memory 5
The light emitting LED control circuit 100 may be omitted, and the CPU 31 may directly control the resistance value of the potentiometer 50. At this time, the CPU 31 includes a circuit that generates a control signal for setting a resistance value of the potentiometer 50 corresponding to the communication distance from the communication distance.

In the above embodiment, the current flowing through the light emitting LED is changed by the potentiometer 50 in order to change the amount of infrared light.
The voltage of the power supply of the light-emitting LED may be changed without using.

[0090]

As described above, in the transmitting apparatus,
By changing the operating current according to the distance to the external receiving device, power can be efficiently consumed. In addition, since the transmitting device transmits information with the intensity of the electromagnetic wave according to the distance to the external receiving device, stable communication can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an infrared communication device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a circuit configuration of an LED transmitting / receiving circuit.

FIG. 3 is a circuit diagram showing a circuit configuration of a potentiometer 50.

FIG. 4 is a diagram showing a relationship between a distance between a transmitting device and a receiving device and an operating current flowing through a light emitting LED.

FIG. 5 is a diagram for explaining a technique disclosed in Japanese Patent Application Laid-Open No. 6-224855.

[Explanation of symbols]

 3 Transmission / Reception Data Memory 4 Communication Distance Circuit 5 Resistance Data Memory 6 Light Emitting LED 7 Transmission Driver 8 Photodiode (PD) 9 Receiver (REC) 10 Decoder 11 Input Unit 31 CPU 32 CPU 50 Potentiometer 60 Ultrasonic Sensor 100 Light emitting LED control circuit 200 IR communication circuit 300 IR communication circuit 400 LED transmission / reception circuit 500 LED transmission / reception circuit 600 infrared communication device 700 infrared communication device TXD transmission data RXD reception data

Claims (13)

[Claims] 1. A transmitting device for transmitting information using electromagnetic waves, a distance measuring means for measuring a distance to a receiving device for receiving information, and transmitting information using electromagnetic waves to the receiving device. A transmitting apparatus comprising: a transmitting unit; and a control unit that controls the intensity of an electromagnetic wave transmitted by the transmitting unit according to a measurement result of the distance measuring unit. 2. The control means stores a distance to the receiving device and information for changing an intensity of an electromagnetic wave transmitted by the transmitting means to an intensity corresponding to the distance, and uses this information. The transmitting apparatus according to claim 1, wherein the transmitting unit controls the intensity of the electromagnetic wave transmitted. 3. The transmitting apparatus according to claim 1, wherein said distance measuring means measures a distance using an ultrasonic wave. 4. The transmitting apparatus according to claim 1, wherein said transmitting means uses infrared rays as electromagnetic waves. 5. The apparatus according to claim 1, wherein said distance measuring means is installed close to said transmitting means.
The transmission device according to claim 1. 6. The transmitting means according to claim 1, wherein said transmitting means has directivity, and said distance measuring means has the same directivity as that of said transmitting means. The transmitting device according to claim 1. 7. A transmitting device for transmitting information at a strength of an electromagnetic wave corresponding to the measured distance, comprising: a transmitting device for transmitting information at a distance to an external device for receiving the information; A communication device, comprising: a receiving device that receives information. 8. The transmitting device stores a distance to the external device and information for changing the intensity of electromagnetic waves transmitted by the transmitting device to an intensity corresponding to the distance, and uses the information to store the information. The communication device according to claim 7, wherein the intensity of the electromagnetic wave transmitted by the transmission device is changed. 9. The communication device according to claim 7, wherein the transmission device measures a distance using an ultrasonic wave. 10. The communication device according to claim 7, wherein said transmission device uses infrared rays as electromagnetic waves. 11. A measuring step for measuring a distance between a transmitting apparatus for transmitting information and a receiving apparatus for receiving the information, and the transmitting apparatus transmits the information by an electromagnetic wave having an intensity corresponding to a measurement result in the measuring step. A communication method, comprising: transmitting. 12. The communication method according to claim 11, wherein said measuring step includes a step of measuring a distance using an ultrasonic wave. 13. The communication method according to claim 11, wherein said transmitting step includes a step in which said transmitting apparatus transmits information by infrared rays as electromagnetic waves.