JPH07250033A - Transmitter for infrared signal - Google Patents

Abstract

PURPOSE:To provide the transmitter for infrared signal with which the transmission output of infrared signals can be changed, battery keeping time can be prolonged, the cabinet of the device can be compactly and lightly formed and the service life of a light emitting element is prolonged. CONSTITUTION:This device is provided with a control content selecting means 3 for selecting control contents, infrared ray emitting means for emitting infrared rays for signals, light emission driving means for emitting the infrared ray emitting means by supplying power, infrared ray emitted quantity varying means, infrared ray emitted quantity selecting means 4, light emission control means, pulse wave output means and wave width varying means for pulse waves to be outputted. Further, the pulse wave output means is a monostable multivibrator, and the wave width varying means combines a capacitor for wave width measurement and a variable resistor which resistance value can be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter of a remote control device using an infrared signal, and more particularly to an infrared signal transmitter having a variable amount of signal infrared emission.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram of an infrared signal transmitter in a conventional example for remotely controlling a controlled device using an infrared signal. In the figure, an infrared signal transmitter 18 is provided with an operation key 19 for inputting the operation content of a controlled device (not shown) that is performed by remote control, and a pulse corresponding to the operation content operated by this operation key 19. IC 20 for transmitter that outputs a signal
And a driver 22 for supplying a current to an infrared light emitting element 21 such as an infrared light emitting diode to intermittently emit light in accordance with a pulse code output from the transmitter IC 20.
And a battery 23 for supplying the light emitting power and the device driving power.

When designing such an infrared signal transmitter 18, the "electrically transmittable distance" as to how far the infrared signal to be transmitted reaches is an important design guideline and is controlled remotely. In consideration of the receiving sensitivity of the controlled device and the receiving device, the emission amount of the signal infrared light is determined so as to satisfy the "transmittable distance". That is, if it is necessary to make the infrared signal reach 20 meters ahead, it will be designed to have a light emission amount corresponding to this.

By the way, even if an infrared signal transmitter having a transmission distance of 20 meters is designed as in this example, it is necessary to always reach the infrared signal up to 20 meters, which is the maximum transmission distance. However, even if one considers an example of remote control of a television, video, air conditioner, etc., the most frequently used is remote control of controlled equipment, which is at most a few meters away. As described above, the infrared signal transmitter for remote control is often used at a distance equal to or shorter than the transmittable distance, but even in such a case, the infrared signal transmitter itself is always At present, infrared signals are transmitted at the maximum light emission output.

[0005]

DISCLOSURE OF THE INVENTION Problems to be solved by the fact that the emission output of the infrared signal is excessively high include the following points. The transmitted infrared signal may be reflected on an object such as a wall or ceiling, and may affect devices other than the target controlled device. That is, for example, when an infrared signal is transmitted by an infrared signal transmitter for the purpose of operating a specific air conditioner in a room where a plurality of air conditioners are installed, the operation of other air conditioners may change. . Since the light emission output of the infrared signal transmitter is proportional to the power consumption (current value flowing through the light emitting element), it is a waste of battery to always transmit the infrared signal at the maximum light emission output. A light emitting element for emitting signal infrared rays is usually
The larger the output, the faster the deterioration. This point will be described below.

FIG. 11 shows a current value I _FP flowing through a certain light emitting element.
Is a graph showing the progress of deterioration of the light emitting element (reduction of light emission output) in the case of 1 A (ampere) and 500 mA,
The vertical axis shows the light emission output as a relative value with the maximum output being 1,
The horizontal axis indicates the light emitting operation time of the light emitting element. The other conditions such as a wave width (PW) of 5 ms and a duty ratio of 1/10 described later are the same. According to this graph, when the current value I _FP is 1 A, the light emission output sharply decreases after 100 hours, and after 1000 hours, it is halved to about 0.5 with respect to the initial light emission output 1. is doing.
On the other hand, when the current value I _FP is 500 mA, the degree of decrease is gentle, and the light emission output exceeds 0.8 even after 1000 hours have passed. As described above, the infrared light emitting element deteriorates more as the flowing current increases and as the light emitting time increases.

The present invention was devised in view of such problems, and the transmission output of the infrared signal can be changed according to the distance to the controlled device, and the infrared signal is always transmitted with an appropriate transmission output. It is an object of the present invention to provide an infrared signal transmitter that can be used, and also to provide an infrared signal transmitter that can prevent unnecessary battery consumption and extend the battery duration.

In addition, since it is possible to mount a battery having a small capacity when it is not necessary to extend the battery duration, an infrared signal transmitter having a small and lightweight device housing and easy to handle. The purpose is to provide. Further, another object of the present invention is to provide an infrared signal transmitter capable of extending the life of the infrared light emitting element.

[0009]

In order to achieve the above-mentioned object, the present invention is an infrared signal transmitter for remotely controlling a controlled device by an infrared signal, and the transmission output of the infrared signal to be transmitted is changed. A possible infrared signal transmitter, which is a control content selection means, such as an operation key, for selecting the control content of the controlled device, and infrared light emission, for example, an infrared light emitting diode for emitting signal infrared light. Means, a light emission driving means, which is a driver for causing the infrared light emitting means to emit light by supplying power to the infrared light emitting means based on a received drive signal, and a light emission amount of the infrared light emitting means, for example, C
A PU, a clock timer, a monostable multivibrator, and infrared light emission amount varying means which is a time constant circuit unit externally attached to the monostable multivibrator, and a transmission output selection switch for selecting the light emission amount of the infrared light emitting means. Which is selected by the infrared emission amount selection means and the control content selection means, and is transmitted to the light emission drive means as the drive signal for intermittently transmitting the control content to be transmitted, for example, CP
The light emitting control means is U.

Further, the infrared light emission amount varying means is capable of varying a pulse wave output means which is a drive signal for driving the infrared light emitting drive means and a pulse width of the pulse wave output by the pulse wave output means. When the pulse wave is turned on, the infrared light emission drive means is driven and the infrared light emission means emits light during the time of the wave width set by the wave width change means.

Further, the pulse wave output means is a monostable multivibrator, and the wavewidth changing means is connected to an output side transistor of the monostable multivibrator so that a wavewidth determining capacitor and a resistance value of the output pulse wave can be changed. The configuration is a combination of various variable resistors.

[0012]

[Operation] The operation of the present invention is as follows. The control content selection means selects the control content of the controlled device to be remotely controlled. Further, the infrared light emission amount selection means selects how much light emission amount of the infrared light signal is to be transmitted at the time of transmission, and in response to this selection, the infrared light emission amount varying means emits light when the infrared signal is transmitted. Set the amount. The light emission drive means supplies light emission drive power to the infrared light emission means according to the received drive signal. The light emission control means transmits a coded intermittent drive signal to the drive means, and in response to this drive signal, the light emission drive means supplies electric power to the infrared light emission means, whereby the infrared light emission amount changing means sets it. The infrared light emitting means emits light with the emitted light amount and is transmitted as an infrared signal.

Further, as the infrared ray emission amount varying means,
The pulse wave output means is an infrared ray for transmission as shown in FIG.
As a carrier frequency for carrying a signal, for example, 38
kH _ZThe modulated light with a certain degree of modulation is output. This 38
kH_ZThe modulated light of is for one cycle of ON and OFF.
That is, the carrier cycle is 26.3 μs.
In the illustrated example, the ON time is 8.77 μs. This
The output time corresponding to the wave width of the ON signal of
The infrared light emitting means emits a dynamic signal. The wave width is acceptable
The transformation means changes the ON time of this wave width.
The longer the ON time is, the longer the light emission time of the infrared light emitting means will be.
As the amount of infrared light emitted increases, the ON time is shortened.
As the light emission time becomes shorter, the amount of infrared light emitted also decreases.
It In this way, the ON / OFF of the output pulse wave
Ratio, that is, to change the duty ratio described later
The amount of emitted infrared light also changes.

The duty ratio is as shown in FIG.
As shown in FIG. 5B, it is represented by the ratio of ON time to 1 cycle time of the pulse wave that turns ON and OFF, and FIG.
The duty ratio D ₁ of the pulse wave is D ₁ = T ₁ / T, and the duty ratio D ₂ of the pulse wave of FIG.
D ₂ = T ₂ / T. In this case, the duty ratio D ₁ of FIG. 5A is 30%, and the duty ratio D ₁ of FIG.
_{If 2} is 20%, D ₂ / D ₁ = 20 / 30≈0.6
7, it can be seen that the pulse wave of FIG. 5B emits light at a light emission ratio of 67% as compared with the pulse wave of FIG. As described above, when the duty ratio is small, that is, when the pulse width of the pulse wave is narrow, the amount of emitted infrared light also decreases and the transmission output decreases, but conversely the power consumption of the battery decreases. The graph of FIG. 6 shows the light emission ratio when the duty ratio is 5% to 30% when the light emission amount of the infrared light emitting means is 1 when the duty ratio is 30%.

FIG. 7 shows an example in which the modulated light as described above is used as a pulse code which is interrupted in accordance with a fixed communication procedure (FIG. 4 is a diagram showing the structure of the modulated light in which the portion A of FIG. 7 is enlarged. is there). According to this figure, the light emission of 9ms first,
Following the start bit consisting of extinction of 4.5 ms, "1" is set when the interval from emission to emission is 1.125 ms, and "1" when the interval from emission to emission is 2.25 ms. , The transmitted control content is "0",
It is transmitted as an intermittent pulse signal encoded with "1". The light emission control means sends an intermittent drive signal corresponding to the intermittent pulse signal to the light emission drive means,
As a result, the infrared light emitting means emits light and an infrared signal is transmitted.

When the infrared light emitting diode is caused to emit light by using such modulated light, the light emission amount (battery usage amount) is “voltage × current × ON time”. The amount of light emission can be reduced by keeping the ON constant and shortening the ON time. When the modulated light as shown in FIG. 4, the carrier frequency 38KH _Z, among the carrier period 26.3Myuesu, ON time 8.77μs
Therefore, 8.77 / 26.3≅⅓, and the actual light emission time is 3 ms, which is about one-third of 9 ms as a signal component. By the way, the modulated light shown in FIG. 8 is the case where the ON time is reduced to 5.0 μs. In this case, 5.0 / 26.3≈1 / 5.3, which is 9
Of the ms signal, the actual light emission time is as short as 1.7 ms. In this case, the actual light emission time is from 3 ms to 1.
Despite the decrease to 7 ms, there is no change in the data format of the pulse code, that is, the light is initially emitted for 9 ms, so that there is no obstacle in information transmission. In this way, by changing the duty ratio of the carrier frequency used for data transmission, the light emission amount of the infrared light emitting diode can be increased / decreased, and the power consumption is also increased / decreased accordingly.

The monostable multivibrator as the pulse wave output means outputs a pulse wave as the modulated light. That is, FIG. 9 shows an example of a monostable multivibrator. In the state where there is no input trigger, the transistor Tr ₁ on the input side is ON and the transistor Tr ₂ on the output side is OF.
It becomes F, and the pulse wave output is turned off. When the input trigger enters, the transistor Tr ₁ turns off and the transistor T
r ₂ is turned on and a pulse wave is output. The width of the output pulse wave is determined by a time constant circuit composed of a capacitor C connected to the base of the transistor Tr ₂ and a resistor R. That is, the duty ratio can be changed by changing the values of the capacitor C and the resistor R. A capacitor C14 and a resistor R14 shown in FIG. 3, which will be described later, are time constant circuits externally attached to the monostable multivibrator 13 so that the duty ratio can be changed. In this case, since it is relatively difficult to change the capacitance of the capacitor C14, the resistor R14 is a variable resistor, and the duty ratio is changed by changing the resistance value.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. FIG. 1A is an external perspective view of an infrared signal transmitter according to the first embodiment. In the figure, the infrared signal transmitter 1 has an elongated box-shaped casing, and has an infrared signal transmission window 2 on the front surface thereof, which is shielded by a translucent member that transmits only infrared signals of a predetermined wavelength. is doing. In addition, a plurality of operation keys 3a, 3b to 3n as the control content selection means for selecting the control content of the controlled device control (not shown) and the infrared light emission amount selection means on the upper surface of the device casing. It has a transmission output selection switch 4. This transmission output selection switch 4 is a rotary type volume knob 4a in this embodiment, and is shown in FIG.
As shown in FIG. 6, in this embodiment, the duty ratio can be selected in 6 steps of 5%, 10%, 15%, 20%, 25%, 30%, that is, the light emission amount. However, the duty ratio is not limited to this, and the duty ratio may be selected steplessly. Also,
In this embodiment, the maximum duty ratio is set to 30% to prevent thermal destruction of the infrared light emitting diode described later. The power switch 5 is also used as the transmission output selection switch 4, and the power is turned off when the volume knob 4a is fully rotated counterclockwise.

Reference numeral 6 denotes a display section made of liquid crystal, which has the transmission output selection switch 4 and the operation key 3a.
The operation contents selected in 3n are displayed to prevent erroneous input. Reference numeral 7 is a band for carrying the device.

FIG. 3 is a diagram showing a schematic internal configuration of the infrared signal transmitter 1. In the figure, the operation keys 3a to 3n, the transmission output selection switch 4 and the display unit 2 are shown.
Is connected to the control unit 8. The control unit 8 includes a CPU 9 for performing various calculations, a system memory 10 for storing a system program, a data memory 11 for storing control contents and pulse code data, and a clock timer 12 for generating a clock frequency.

A monostable multivibrator 13 is connected to the output side of the control unit 8 as the infrared ray emission amount varying means. As described above, the monostable multivibrator 13 is externally provided with the time constant circuit section 14 for changing the duty ratio, which includes the capacitor C14 and the variable resistor R14 whose resistance value can be changed. The resistance value of the variable resistor R14 is changed by operating the transmission output selection switch 4, and the duty ratio of the pulse wave output from the monostable multivibrator 13 is changed as described above by changing the resistance value.

The driver 15 as the light emission drive means
Receives the pulse signal output from the monostable multivibrator 13 and receives the infrared light emitting diode 16 from the battery 17.
Is supplied with electric power for light emission, whereby the infrared light emitting diode 16 emits an infrared signal.

In the infrared signal transmitter 1 configured as described above, first, the transmission output selection switch 4 is set to 5% to 30%.
From the duty ratio of%, the position is rotated to the position of the desired duty ratio according to the transmission distance. By this rotation operation, the power switch 5 of the apparatus is turned on, and the resistance value of the variable resistor R14 of the externally attached time constant circuit unit 14 is changed so that the selected duty ratio output is obtained.

Next, when the operation keys 3a to 3n corresponding to the control contents to be transmitted are operated, the CPU 9 of the control unit 8
According to the system program stored in the system memory 10, based on the clock frequency generated by the clock timer, O corresponding to the operation content of the operation keys 3a to 3n
The pulse code data encoded by the N and OFF interruptions is read from the data memory, and the intermittent signal based on the pulse code data is output to the monostable multivibrator 13 as the input trigger. The monostable multivibrator 13 operates by receiving the pulse-coded input trigger, and transmits the pulse signal having the set duty ratio to the driver 15. In the driver 15, electric power is supplied from the battery 17 to the infrared light emitting diode 16 based on the received pulse signal, whereby the infrared light emitting diode 16 emits light and the infrared signal is transmitted.

The selection by the transmission output selection switch 4 and the operation contents by the operation keys 3a to 3n are controlled by the CPU 9
Are sequentially displayed on the display unit 6 under the control of.

Next, a second embodiment will be described with reference to FIG. In the figure, in the infrared signal transmitter 1'of the second embodiment, the transmission output selection switch 4 is
It is a two-level setting of level and low level, and the operation piece 4b
When is pushed forward, High level is selected, and when the operation piece 4b is moved backward, Low level is selected. In this case, the duty ratio is set to 30% at the high level and 15% at the low level. The other structure and operation are the same as those of the first embodiment.

The present invention is not limited to the above embodiment, and for example, the control unit for outputting the intermittent pulse code data corresponding to the control content to be transmitted is dedicated to the transmission of the infrared signal (see FIG. 3) may be configured by using an IC with a single chip, and instead of the monostable multivibrator 13 for varying the light emission amount of the infrared light emitting diode, a variable duty output (PWM output) may be used. It is also possible to use an IC or the like having a).

[0028]

As described above, according to the present invention, the infrared signal transmission output can be changed according to the distance to the controlled device, and the infrared signal can always be transmitted at an appropriate transmission output. It can be an infrared signal transmitter. Therefore, there is no inconvenience that, for example, a device other than the target controlled device is operated when an infrared signal is transmitted with a transmission output that is disproportionate to the transmission distance, and useless battery consumption can be prevented. Therefore, the battery duration can be extended.

Further, since it is possible to mount a battery having a small capacity when it is not necessary to extend the battery duration, it is possible to provide an infrared signal transmitter which is small and lightweight and easy to handle. it can.

Further, since the unnecessary infrared light emitting element is not made to emit light, the infrared signal transmitter can extend the life of the infrared signal light emitting element.

[Brief description of drawings]

FIG. 1A is an external perspective view of a first embodiment,
FIG. 7B is a diagram showing a power source and a transmission output selection switch portion.

FIG. 2 is an external perspective view of a second embodiment.

FIG. 3 is a diagram showing a schematic internal configuration of an infrared signal transmitter in the first and second embodiments.

FIG. 4 is a diagram showing an example of a carrier frequency for carrying transmission data.

5A and 5B are diagrams for explaining a duty ratio of a pulse wave.

FIG. 6 is a duty ratio of 5% to 30 when the light emission amount of the infrared light emitting means is 1 when the duty ratio is 30%.
It is a figure showing the light emission ratio in the case of%.

FIG. 7 is a diagram showing an example in which modulated light is a pulse code which is intermittent according to a fixed communication procedure.

FIG. 8 is a diagram showing an example of a carrier frequency for carrying transmission data.

FIG. 9 is a diagram showing an example of a monostable multivibrator.

FIG. 10 is a schematic configuration diagram of an infrared signal transmitter in a conventional example.

FIG. 11 shows a current value I _FP flowing through a certain light emitting element is 1 A and 50.
6 is a graph showing the progress of deterioration of a light emitting element (reduction of light emission output) in the case of 0 mA.

[Explanation of symbols]

 1 ・ ・ Infrared signal transmitter 1 '・ Infrared signal transmitter 2 ・ ・ Light-transmitting windows 3a, 3b to 3n ・ Operation keys 4 ・ ・ Transmission output selection switch 5 ・ ・ Power switch 6 ・ ・ Display unit 7 ・ ・Portable band 8 ... Control unit 9 ... CPU 10 System memory 11 Data memory 12 Clock timer 13 Monostable multivibrator 14 Time constant circuit unit 15 Driver 16 Infrared light emitting diode 17 Battery

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04B 10/04 10/06 10/00 H04Q 9/00 311 U

Claims (3)

[Claims] 1. An infrared signal transmitter for remotely controlling a controlled device according to an infrared signal, wherein the transmission output of the transmitted infrared signal is changeable, and the controlled device is controlled. Control content selection means for selecting content, infrared light emitting means for emitting signal infrared light, and light emission for supplying power to the infrared light emitting means based on the received drive signal to cause the infrared light emitting means to emit light Drive means, infrared light emission quantity changing means for changing the light emission quantity of the infrared light emitting means, infrared light emission quantity selecting means for selecting the light emitting quantity of the infrared light emitting means, and selection by the control content selecting means And a light emission control means for transmitting to the light emission drive means as the drive signal for intermittently transmitting the control content to be transmitted. . 2. The infrared ray emission amount varying means includes a pulse wave output means which is a drive signal for driving the infrared ray emitting drive means, and a pulse width of the pulse wave output by the pulse wave output means. 7. The infrared light emitting drive means is driven and the infrared light emitting means emits light during the time of the wave width set by the wave width changing means when the pulse wave is turned on. 1. An infrared signal transmitter according to 1. 3. The pulse wave output means is a monostable multivibrator, and the wavewidth varying means is connected to an output side transistor of the monostable multivibrator so that a wavewidth determining capacitor and a resistance value of an output pulse wave can be changed. 3. The infrared signal transmitter according to claim 2, wherein the transmitter is a combination of various variable resistors.