JPH09172409A - Infrared communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous communication and malfunction by controlling the transmission infrared signal intensity of infrared communication equipments opposing each other at a distance shorter than any other infrared communication equipment of the same kind to be an optimum value corresponding to the distance. SOLUTION: At the time of receiving a line establishing request at first, a controller 1 increases the gain of a transmission amplifier 3 from a minimum stepwise untile receiving a response signal to a first key signal sent from a key signal generation part 11 first and determines the transmission level of an infrared light emitting part 4. At the time of receiving the first key signal first, the controller 1 sends the first key signal by reducing the gain of the transmission amplifier 3 from a maximum stepwise and determines the transmission level of the infrared light-emitting part 4 to a level just before the response signal becomes receiving impossible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared communication device, and more particularly to an infrared communication device that controls the intensity of a transmitted infrared signal to perform communication.

[0002]

2. Description of the Related Art A conventional infrared communication device is disclosed in JP-A-60-
As described in JP-A-153238 and JP-A-1-33879, an automatic gain controller (Automatic Gain Cont) for automatically adjusting the gain of an amplifier so that the output signal of the receiving amplifier is constant on the receiving side.
It has a mechanism to reduce the sensitivity of the detector when the level of the received light signal is continuously high enough and to raise the sensitivity of the detector when the level of the received light signal is continuously low. I am trying to get a good reception state.

[0003]

The above-mentioned conventional infrared communication device has the first problem that erroneous communication occurs when the distance between the transmitting side device and the receiving side device is too close or too far. is there.

The reason is that the infrared light emission intensity on the transmitting side is always fixed to a certain value, so that when the distance between the transmitting and receiving sides is too short, the signal intensity on the receiving side is too strong, causing malfunction of the internal circuit. This is because, if the distance is too long, the signal strength reaching the receiving side is too weak, and it is easily affected by noise.

Secondly, in the conventional infrared communication device built into a personal computer, when infrared communication is performed between the personal computer and the portable terminal in a normal office environment, the transmitted infrared signal strength is always at a certain constant value. It is fixed, even when the mobile terminal of the other party to communicate with is installed close to the personal computer, and also to an infrared communication device other than the mobile terminal (for example, another personal computer installed some distance away). There is a problem that a signal may be transmitted and malfunction may occur.

The reason is that the intensity of the transmitted infrared signal of the infrared communication device on the transmission side is fixed to a certain value,
This is because the effective signal reaches not only the mobile terminal, which is the receiving side of the shortest distance, but also another personal computer installed at some distance.

An object of the present invention is to prevent erroneous communication and erroneous operation by facing each other in a shorter distance than any other infrared communication device of the same kind and controlling the transmitted infrared signal intensity to an optimum value corresponding to the distance. An object is to provide an infrared communication device.

[0008]

An infrared communication device according to a first aspect of the present invention is an infrared communication device that faces each other in a shorter distance than any other infrared communication device of the same type, and the intensity of a transmitted infrared signal is set to the above-mentioned facing distance. It is characterized by optimal control according to.

In the infrared communication device of the second invention, an encoding means for modulating a serial digital signal and a plurality of amplification degrees are provided, and an output electric signal from the encoding means is designated in the plurality of amplification degrees. Transmission amplification means for amplifying with the amplification degree, infrared light emitting means for converting an electric signal output from the transmission amplification means into an infrared signal according to its intensity, and infrared light receiving means for converting a received infrared signal into a corresponding electric signal. A receiving and amplifying means having an automatic gain adjusting mechanism for amplifying an electric signal output from the infrared light receiving means,
Decoding means for demodulating the electric signal from the receiving and amplifying means to obtain a serial digital signal which is the original signal, and when the initial amplification degree of the transmitting and amplifying means is designated as the maximum amplification degree and a communication line establishment request is first received Amplification degree of the transmission amplification means is stepwise until the first amplification signal of the transmission amplification means is designated to be minimum, a first key signal indicating a response request is transmitted, and a second key signal indicating a reception response is first received. To transmit a third key signal indicating the completion of the adjustment of the intensity of the transmitted infrared signal, and when the first key signal is first received, the second key signal is transmitted and then the third key signal of the third key signal is transmitted. The transmission amplification means reduces the amplification degree of the transmission amplification means in a stepwise manner in response to reception, and transmits the first key signal to transmit the second key signal indicating a reception response to the amplification degree immediately before the reception failure occurs. The degree of amplification of the means To is configured to include a control means for sending the third key signal.

An infrared communication device according to a third aspect of the invention is the infrared communication device according to the second aspect, wherein the control means is an independent IC.
It is composed of chips.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings.

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

For communication, two devices shown in FIG.
Installed facing each other. In the following description, the device shown in FIG. 1 will be referred to as device A, and the opposite device will be referred to as device B.
It is assumed that the device A and the device B face each other at a shorter distance than any other infrared communication device of the same type.

As shown in FIG. 1, the infrared communication apparatus according to the first embodiment has a controller 1 for controlling the gain of a transmission amplifier 3 and controlling a transmission infrared signal intensity to an optimum value corresponding to a distance, and a controller 1. An encoder 2 that modulates a digital signal from the transmitter, a transmission amplifier 3 that amplifies the electric signal supplied from the encoder 2 with a gain controlled by the controller 1, and an electric signal supplied from the transmission amplifier 3 to an infrared signal. The infrared light emitting unit 4, the infrared light receiving unit 5 for converting the infrared signal received from the opposite device into an electric signal, the receiving amplifier 6 for amplifying the electric signal supplied from the infrared light receiving unit 5, and the receiving amplifier 6 are supplied. It is configured to include a decoder 7 that demodulates an electric signal.

The controller 1 has a built-in program 1
5 establishes a communication line with a partner device facing each other in a shorter distance than any other infrared communication device of the same type and transmits / receives a signal to / from the outside in response to a communication line establishment request from the outside. A control unit 14 that controls the gain of the transmission amplifier 3 and controls the transmission infrared signal strength to an optimum value corresponding to the distance, a key signal generation unit 11 that generates a key signal necessary for establishing a line, and a reception key. It is configured to include a key signal determination unit 12 that determines a signal and a timer 13 that measures an elapsed time.

The key signal generator 11 generates three types of key signals (digital signals). The first key signal K1 is a response request signal for requesting a response, the second key signal K2 is a response signal to K1, and the third key signal K3 is the optimum transmission infrared signal strength. It is a transmission infrared signal strength adjustment complete signal indicating that the value has been adjusted.

The timer 13 starts measuring the elapsed time after transmitting the key signal, is reset when the key signal corresponding to the response signal from the opposite station is received, and the fixed time designated by the control unit 14 elapses. If not reset, an alarm is returned to the control unit 14 and reset.

The encoder 2 turns on / off a carrier (for example, 500 KHz) and modulates it according to a serial digital signal of a combination of 0 and 1 supplied from the controller 1.

The decoder 7 demodulates the serial digital signal of the original signal from the modulated electric signal.

The infrared emitting section 4 converts an electric signal into an infrared signal and has a transfer rate of 19.2 Kb, for example.
In the case of ps, when a carrier is supplied with a modulated electric signal of 500 KHz, an infrared pulse having a period of 2 μS is transmitted for about 52 μS to indicate 0 of the digital signal, and about 1 μm for expressing 1 of the digital signal. The infrared signal is turned off for 52 μS. Input / output level characteristics are assumed to be linear.

The infrared light receiving section 5 performs the inverse conversion of the infrared light emitting section 4.

The transmission amplifier 3 has an amplification section 31 and a gain adjustment section 32 whose gain is controlled by the controller 1. And the gain adjustment has a gain value of a plurality of stages (10 stages for example) from the minimum gain to the maximum gain,
It can be adjusted step by step.

The reception amplifier 6 is an automatic gain adjustment amplifier having an amplification section 61 and a gain adjustment section 62 for adjusting the gain according to the output level.

FIG. 2 is a flow chart showing the operation of the infrared communication device according to the first embodiment. Steps 201-212,
Reference numerals 215 and 224 show the operation of the device A which has received the line establishment request, and steps 201, 202, 215 to 224 show the operation of the device B facing the device A. The reverse is true when the device B receives the line establishment request.

The operation of the infrared communication device of the first embodiment will be described with reference to FIGS. 1 and 2.

The device A and the device B having the block configuration shown in FIG. 1 are opposed to each other, and the operation for establishing the optimum communication line for performing communication will be described. For convenience, the numbers shown in FIG. 1 are suffixed with a to indicate the constituent blocks of the device A, and the numbers shown in FIG. 1 are suffixed with b to indicate the constituent blocks of the device B. For example, the encoder of device A is encoder 2a. The encoder of device B is shown as encoder 2b.

A case where the device A receives a request for establishing a communication line from the outside will be described.

In both initial states of the transmission amplifier 3a of the device A and the transmission amplifier 3b of the device B, their gains (represented by G) are set to the maximum (max) (step 201).

When a request for establishing a communication line is supplied to the device A from the outside (for example, from a personal computer) (step 202)
Controller 1a, G of the transmission amplifier 3a is set to the minimum (min) (step 203), and then K1 is generated and transmitted to the key signal generator 11a (step 20).
At the same time as 4), the timer 13a is activated to start measuring the elapsed time (step 205). At this time, the transmission level of the infrared signal from the infrared emitting section 4a is in the minimum state.

Since the transmission level of the infrared signal from the device A is in the minimum state, the reception level to the device B is extremely weak and the device B cannot receive the signal. Therefore, the device B receives the signal from the device B within a certain time (T1). The response K2 is the key signal determination unit 12a
If it cannot be received at (N branch of step 205), the control unit 14a increments G of the transmission amplifier 3a by one step (step 207), and K2, which is a response from the device B, is a key within T1 time after K1 transmission. K from the device A until the signal determination unit 12a can receive the determination (Y branch of step 205).
The transmission level of the infrared signal corresponding to 1 is gradually increased (loop of steps 204 to 207). However,
Even if G of the transmission amplifier 3a becomes maximum, K2 from the device B
Is not received (YES in step 206)
However, since the communication line cannot be established (step 212), this is notified to the external device that has made a request for line establishment, and the process ends.

On the other hand, the device B can finally receive K1, and when the key signal determination unit 12b determines and receives this (step 2).
(Y branch of 15), the control unit 14b causes the key signal generation unit 11b to generate K2 and transmits it to the device A (step 216), and waits for reception of K3 supplied from the device A (step 217). Since G of the transmission amplifier 3b is the maximum, the transmission level of the infrared signal from the infrared emission unit 4b at this time is in the maximum state.

In this way, the transmission level of the infrared signal corresponding to K1 from the device A is gradually increased to T after transmission of K1.
When K2, which is the response from the device B, can be determined and received by the key signal determination unit 12a within one hour (Y branch of step 205), the transmission level of the infrared signal from the device A is optimally adjusted (device B). Since it is possible to communicate with the device and the level has been adjusted so as not to interfere with other devices), the one-way communication from the device A to the device B has been optimally adjusted.
In order to inform the device B of this, the controller 14a causes the key signal generator 11a to generate K3 and sends it to the device B (step 208), and waits for the optimum adjustment operation from the device B (step 209). N branch, 211 N branch loop).

When the key signal determination unit 12b determines that the device B receives K3 from the device A (Y in step 217).
Branch B), the device B recognizes that the one-way communication from the device A to the device B has been optimally adjusted, and this time, the device B enters the optimal adjustment operation of the one-way communication from the device B to the device A.

In this state, since the gain of the transmission amplifier 3b is maximum, the level of the infrared signal transmitted from the infrared light emitting section 4b is maximum, and if it is left as it is, it may interfere with devices other than the device A. Since it is not, reduce this level and adjust to the optimum level.

Therefore, the control unit 14b reduces the gain of the transmission amplifier 3b, which is currently in the maximum gain state, by one step (step 218), and then the key signal generation unit 11b generates K1 and transmits it to the device A (step S218). 219).

Device A sends K3 and then sends K from device B.
Each time the key signal determination unit 12a can determine 1 (Y branch of step 209), the control unit 14a controls the key signal generation unit 1
1a generates K2 as a response to this K1 and sends it to device B (step 210), and waits for a reaction from device B (loop of steps 209 and 211).

In the device B, every time the key signal determination part 12b determines that the K2 from the device A is received within the fixed time (T1) (Y branch of step 220), the control part 14b sets the gain of the transmission amplifier 3b to one step. After each step (step 21
8), K1 is generated from the key signal generation unit 11b and transmitted to the device A (step 219), and the timer 13b is activated to start measuring elapsed time.

When G of the transmission amplifier 3b reaches the minimum value during the loop operation of the N branches of steps 218 to 221, (Y branch of step 221), this corresponds to the optimum value of the infrared signal level of the device B. It becomes G of the amplifier 3b.

Further, the gain of the transmission amplifier 3b is decreased step by step to generate K1 from the key signal generating section 11b and transmit it to the device A. First, K2 from the device A is keyed within a fixed time (T1). When the signal determination unit 12b cannot determine the reception (N branch of step 220), the control unit 14
In step b, the gain of the transmission amplifier 3b is increased by one step (step 222) to set the optimum gain of the transmission amplifier 3b.

As a result, the transmission level of the infrared signal from the device B from the device B to the device A is optimally adjusted (adjusted to a level at which communication with the device A is possible and there is no interference with other devices). Since the one-way communication from the device B to the device A has been optimally adjusted, the control unit 14b causes the key signal generation unit 11b to generate K3 and sends it to the device A in order to inform that fact. Then, (step 223) the establishment of the line is completed (step 224), so that device B notifies the station to that effect and ends.

On the other hand, when the device A can receive K3 from the device B (Y branch of step 211), the device A recognizes that the one-way communication from the device B to the device A is optimally adjusted, It can be recognized that the two-way communication line between the device A and the device B has been established (step 224), and this is notified to the external device that has made a request for line establishment, and the process ends.

In the infrared communication device of the first embodiment described above, the function of the controller 1 can be realized by a central processing unit controlled by a normally used stored program. In such a case, the central processing unit that performs business or other processing is also required to perform the communication line establishment processing, which increases the load on the central processing unit, and the central processing unit performs the processing in parallel. It may hinder the above-mentioned operations and other processing.

Therefore, in the second embodiment of the present invention, the functions of the controller 1 are integrated into one IC chip. With such a configuration, in the infrared communication device of this embodiment, the central processing unit connected to the infrared communication device causes the controller 1 to perform the communication line establishment process after the communication line establishment request is made, and the communication line from the controller 1 is transmitted. Other processing can be performed until the notification of establishment or communication line non-establishment is received, and the load on the central processing unit can be greatly reduced.

As described above, the infrared communication devices according to the first and second embodiments can transmit the transmitted infrared signal strengths of the infrared communication devices facing each other in a shorter distance than any other infrared communication device of the same type. It is possible to prevent erroneous communication and erroneous operation by controlling the optimum value corresponding to.

[0045]

As described above, the infrared communication device of the present invention has the optimum transmission infrared signal strength of the infrared communication devices facing each other at a shorter distance than any other infrared communication device of the same type. By controlling to 1, there is an effect that erroneous communication and erroneous operation can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing an example of the operation of the infrared communication device according to the first embodiment.

[Explanation of symbols]

 1 Controller 2 Encoder 3 Transmission Amplifier 4 Infrared Light Emitting Section 5 Infrared Light Receiving Section 6 Receiving Amplifier 7 Decoder 11 Key Signal Generating Section 12 Key Signal Determining Section 13 Timer 14 Control Section 15 Program 31, 61 Amplifying Section 32, 62 Gain Adjusting Section

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Claims (3)

[Claims] 1. An infrared communication device that opposes each other at a shorter distance than any other infrared communication device of the same type, wherein the intensity of a transmitted infrared signal is optimally controlled according to the facing distance. apparatus. 2. Encoding means for modulating a serial digital signal, and transmission amplification for amplifying an electric signal output from said encoding means by a designated amplification degree among said plurality of amplification degrees. Means, an infrared light emitting means for converting an output electric signal from the transmission amplifying means into an infrared signal according to its intensity, an infrared light receiving means for converting a received infrared signal into a corresponding electric signal, and an infrared light receiving means from the infrared light receiving means. Reception amplification means having an automatic gain adjustment mechanism for amplifying an output electric signal, decoding means for demodulating an electric signal from the reception amplification means to obtain a serial digital signal which is an original signal, and initial amplification degree of the transmission amplification means. Is designated as the maximum amplification degree and the communication line establishment request is received for the first time, the first key signal indicating the response request by designating the amplification degree of the transmission amplification means to the minimum. Is transmitted and the amplification degree of the transmission amplification means is increased stepwise until the second key signal indicating the reception response is first received, and the third key signal indicating the completion of the intensity adjustment of the transmission infrared signal is transmitted. When the first key signal is first received, the second key signal is transmitted, and then the amplification degree of the transmission amplifying means is decreased stepwise in response to the reception of the third key signal, whereby the first key signal is received. And a control means for transmitting the third key signal by designating the amplification degree of the transmission amplification means to the amplification degree immediately before the reception of the second key signal indicating the reception response becomes impossible. An infrared communication device comprising: 3. The infrared communication device according to claim 2, wherein the control means is composed of an independent IC chip.