JPH02280427A - Infrared ray output device - Google Patents

Abstract

PURPOSE:To send infrared-ray with an optimum luminous quantity for the distance between a transmission means and a received means by receiving reflected infrared ray sent and reflected to the received section from the transmission means by the reception means, and varying the quantity of light emission of the infrared ray sent from the transmission means by the light quantity variable means based on the quantity of light reception. CONSTITUTION:A reception means 1 receiving a reflected infrared ray light sent and reflected from the transmission means to the reception section and light quantity variable means 2-6 varying the light emission of the infrared ray sent from the transmission means 23 based on the light emission quantity of the reflected infrared ray are provided. Since the infrared ray with the quantity of light emission optimum to the distance between the infrared ray reception section 1 and the infrared ray emission section 23 is sent, accurate data communication is stably executed from a very near distance to a remote distance. Moreover, as the transmission reception distance is reduced, since the power consumed by the transmission means is reduced, the service life of the battery is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an infrared light output device that serves as a signal source for a remote control device or the like.

[Conventional technology]

Conventionally, an infrared light output device such as an infrared remote controller (infrared remote control device) is configured as shown in FIG.

FIG. 3 is a circuit block diagram showing an example of this type of infrared light output device, in which 21 is a controller, and a control signal instructed to be output is sent from the boat po through a resistor R1 to the base of a transistor 22 which serves as a driver. Output to. The transistor 22 switches based on the 0N10FF signal applied to its base, causing the infrared light emitting diode 23 to emit light.

Note that the anode side of the infrared light emitting diode 23 is connected to a resistor R.
A predetermined potential is applied via 2.

In this manner, the conventional infrared light output device performs light transmission control based on whether or not the infrared output of the infrared light emitting diode 23 has a preset value.

[Problem to be solved by the invention]

However, in the above-described conventional method, in order to enable long-distance transmission, as much current as possible must be passed through the infrared light emitting diode 23 shown in FIG.

However, although the intensity of the infrared light is proportional to the current flowing through the infrared light emitting diode 23, the intensity of the infrared light reaching the receiving side is inversely proportional to the square of the distance between the transmitter and the receiver. Therefore, if the current flowing through the infrared light emitting diode 23 is set to 100 mA in order to guarantee transmission over a distance of 10 m, the current required for transmission over a distance of 1 m is 1 mA. However, according to the transmitting circuit shown in Figure 3, 1
As a result, a current of 00 mA is consumed, resulting in an increased power loss rate, and when using a battery as a power source, a problem arises in that the life span is shortened.

On the other hand, if the distance difference is large, for example in the above example,
If the signal was accidentally transmitted at a distance of 10 cm, the infrared detection section on the receiving side would become saturated, which could cause a problem in which reception would be impossible.

This invention was made to solve the above problems, and by adjusting the amount of infrared light output to be transmitted according to the reflection port of the transmitted infrared light output, the power on the transmitter side is reduced. The purpose of the present invention is to obtain an infrared light output device that can significantly reduce consumption and also realize data transfer at a stable and optimal level in all distance relationships from extremely short distances to long distances.

(Means for Solving the Problems) An infrared light output device according to the present invention includes a receiving unit that receives reflected infrared light that is transmitted from a transmitting unit to a receiving unit and reflected, and a receiving unit that receives reflected infrared light that is reflected by the receiving unit. and a light amount variable means for varying the amount of infrared light transmitted from the transmitting means based on the amount of reflected infrared light emitted.

[Effect]

In this invention, when an infrared ray is transmitted from the transmitting means to the receiving part, the receiving means receives the reflected infrared light that is transmitted to the receiving part and reflected. The light amount variable means varies the amount of infrared light transmitted from the transmitting means based on the amount of external light emitted, and transmits the infrared rays at the optimum amount to the receiving section based on the distance between the transmitting means and the receiving means. Send to.

(Embodiment) FIG. 1 is a block diagram illustrating the configuration of an infrared light output unit showing an embodiment of the present invention, and the same parts as in FIG. 3 are given the same reference numerals.

In the figure, 1 is a photodiode constituting the receiving means of the present invention, the anode side of which is connected to a capacitor 3.
The capacitor 3 is charged in accordance with the received reflected infrared light. , 2 are high resistors, which discharge the charge stored in the capacitor 3 when no reflected infrared light is input. 4 is an operational amplifier configured to impedance convert the light amount potential applied to the non-inverting terminal side, control the current flowing to the base of the transistor 5 via the resistor 6, and control the current flowing to the infrared light emitting diode 23. It becomes.

Note that when an infrared ray is transmitted from the infrared light emitting diode 23 constituting the transmitting means to the receiving section (the infrared receiving section 15 to be described later), the reflected light is transmitted to the receiving section and reflected. Photodiode that constitutes the means for receiving infrared light]
The light amount variable means (consisting of an operational amplifier 4, a resistor 6, a transistor 5, etc.) receives the reflected infrared light from the infrared light emitting diode 23 based on the amount of the received reflected infrared light. Variable amount, infrared light emitting diode 2
Infrared rays with an amount of light emitted that is optimal for the distance between 3 and the receiving means are transmitted to the receiving section.

FIG. 2 is a relative relationship diagram illustrating the infrared light transmission/reception state shown in FIG. (output from the infrared light emitting diode 23 shown in the figure) is transmitted to the infrared light receiving section 15 of the receiver 14. Reference numeral 13 indicates a reflected infrared light beam (reflected infrared light), which corresponds to the tip of the infrared light beam 12 and enters the photodiode 1 shown in FIG.

Next, the operation shown in FIG. 1 will be explained with reference to FIG.

When the infrared light 12 according to the command is transmitted from the infrared light emitting unit 11 of the remote control transmitter 10 to the infrared light receiving unit 15 of the receiver 14, a part of it is reflected by the infrared light receiving unit 15, and the reflected red light is External light 13 enters the photodiode 1 provided in the infrared light emitting section 11.

At this time, a current corresponding to the amount of reflected infrared light 13 is generated in the photodiode 1 (photoelectrically converted), and the capacitor 3 is charged up. A DC voltage proportional to the intensity of the reflected infrared ray 13 is applied to the non-inverting input side of the operational amplifier 4 after being smoothed by the capacitor 3 . Therefore, the impedance is converted by the operational amplifier 4, and the base current of the transistor 5 is controlled to control the voltage applied to the infrared light emitting diode 23, thereby varying the light emission scene.

In this way, the amount of infrared light 12 is optimal for the infrared light receiving section 15 based on the distance between the infrared light receiving section 15 and the infrared light emitting section 11.
can be sent.

Incidentally, in the above embodiment, a case has been described in which the voltage applied to the infrared light emitting diode 23 is controlled by an analog circuit, but the analog potential obtained by photoelectrically converting the reflected infrared light ray 13 is A/D converted, The amount of emitted light may be controlled by controlling the voltage applied to the infrared light emitting diode 23 from an applied voltage table based on the reflected light amount data.

〔Effect of the invention〕

As explained above, the present invention is based on the receiving means for receiving the reflected infrared light transmitted from the transmitting means to the receiving section and reflected, and the amount of emitted light of the reflected infrared light received by the receiving means. Since a light amount variable means is provided to vary the amount of infrared light emitted from the transmitting means, it is possible to transmit infrared light with the optimum amount of emitted light depending on the distance between the infrared receiver and the infrared emitter. Accurate and stable data communication can be performed over long distances.

Further, as the transmission/reception distance is shortened, the power consumed by the transmitting means is reduced, so that, for example, in a battery-powered infrared light output device, excellent effects such as prolonging the battery life can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the configuration of an infrared light output device showing an embodiment of the present invention, FIG. 2 is a relative relationship diagram explaining the infrared light transmission/reception state shown in FIG. 1, and FIG. The figure is a circuit block diagram showing an example of this type of infrared light output device. In the figure, 1 is a photodiode, 2 is a high resistor, 3 is a capacitor, 4 is an operational amplifier, and 5 is a transistor. Figure 1 3: Capacitor 4: Operational amplifier 5: Transistor

Claims (1)

[Claims] In an infrared light output device having a transmitting means for transmitting modulated infrared light to a remote receiving section, a receiving means for receiving reflected infrared light transmitted from the transmitting means to the receiving section and reflected. and a light amount variable means for varying the amount of infrared light emitted from the transmitting means based on the amount of reflected infrared light received by the receiving means.