JPH08138153A - Method and circuit for dynamic lighting of led - Google Patents

Abstract

PURPOSE: To reduce the power consumption in the whole of a communication equipment by synchronizing with the timing of the intermittent communication of the communication equipment so as to turn on LED at the time of reception and to turn off LED at the time of transmission. CONSTITUTION: An instruction to turn on or off LED is issued by CPU (or software) 4. The instruction to turn on or off which is issued by software is held by a register 1. The timing of transmission and reception to the communication equipment communicating intermittently is generated by a timing generation part 2. Then, when the timing of the turning-on instruction held in the register 1 and the reception of the timing generation part 2 are coincident with each other at an AND circuit 3, a lighting signal is outputted to LED 5. Thereby, current flows to LED 5 through a current limiting resistor 6 to turn on LED on LED 5. In this case, a signal from the AND circuit 3 to LED 5 is controlled to be outputted only at the time of reception, and LED 5 is controlled to be turned off at the time of transmission. Consequently, power consumption in the whole communication equipment is reduced by the part reduced by turning off LED 5 at the time of transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED for illuminating an operation display or an operation unit / display unit of a communication device for intermittent transmission / reception.
Dynamic lighting method and circuit.

[0002]

2. Description of the Related Art Lighting / extinguishing control of LEDs (excluding a power lamp) of a conventional communication device is performed by a lighting or extinguishing command issued from software. Therefore, L
The ED is continuously turned on.

That is, a continuous lighting state is maintained from a software-controlled lighting instruction to a light-off instruction.

FIG. 4 shows the power consumption of the intermittent transmission / reception communication device on the time axis. In the figure, the shaded portion of the current consumption at the time of transmission and reception is the current consumption of the LED.

[0005]

As described above, the conventional L
The ED lights continuously during transmission and reception, and this LED
There is a drawback that the current consumption of lighting up is added to the power consumption of the communication device and power consumption increases.

It is an object of the present invention to suppress an increase in the current consumption in the operation display or the lighting of the LED for illuminating the operation unit / display unit, which is a problem of the prior art, and reduce the current consumption of the entire communication device.

[0007]

The above object is achieved by a method of controlling lighting / extinguishing so that an LED is turned on at the time of reception and the LED is turned off at the time of transmission in synchronization with the timing of intermittent transmission / reception of a communication device which performs intermittent transmission / reception. It

[0008] Further, the above object is to provide a register for holding a lighting or extinguishing instruction issued by software, a timing generation unit for generating transmission and reception timings for a communication device for intermittent transmission and reception, and a lighting instruction held in the register. And a logic gate that outputs a lighting signal to the LED when the reception timings of the timing generation unit coincide with each other.

[0009]

The communication device that performs intermittent transmission / reception repeats transmission / reception at regular intervals. In addition, it consumes a large amount of current when transmitting compared to when receiving. Therefore, the LED is turned off during transmission to reduce the current during transmission.

The lighting control utilizing the intermittent transmission / reception is applied to the one which is executed at an intermittent transmission / reception interval at a speed equal to or higher than the speed at which human eyes perceive flicker (for example, a 2.5 mS cycle used in PHS). And by making the LED blink at a speed faster than the speed at which human eyes perceive flicker, it appears as if they were lighting continuously, and this lighting / light-off control (hereinafter referred to as dynamic lighting) reduces current consumption. To do.

[0011]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 is a configuration diagram of a dynamic lighting circuit according to an embodiment of the present invention, which includes a register 1, a transmission / reception timing generation unit 2, and an AND circuit 3.
It consists of. The timing generation unit 2 uses the output of the transmission / reception timing generation circuit included in the communication device. An instruction to turn on or off the LED is issued by the CPU (software) 4. A lighting or extinguishing instruction issued by software is held by the register 1. The timing generation unit 2 generates transmission and reception timings for a communication device that performs intermittent transmission and reception. When the lighting instruction held in the register 1 and the reception timing of the timing generation unit 2 match in the AND circuit 3, L
A lighting signal is output to ED5. As a result, a current flows through the LED 5 through the current limiting resistor 6 and the LED 5 is turned on.

FIG. 2 shows the amount of current consumption at the time of reception and transmission by the communication device which performs intermittent transmission / reception, and the shaded portion represents the amount of current consumption of the LED. The signal output from the AND circuit 3 to the LED 5 is controlled only during reception, and the LED 5 is controlled to be turned off during transmission. Therefore, the power consumption of the entire communication device is reduced by the amount that the LED 5 is off during transmission. Further, a large current consumption during transmission can be suppressed to a small amount by turning off the LED 5.

The power consumption in the case of implementing the present invention is as follows: the appropriate current of the LED used in the communication device is 10 mA / piece, the transmission time is 2.5 mS, and the reception time is 2.5 mS.
When the single power consumption is calculated as follows, it becomes 5 mAH, and a 50% power saving effect can be obtained as compared with the conventional 10 mAH.

Since each PHS main unit is equipped with one LED, a power saving effect according to the above conditions can be obtained.

In FIG. 3, the LED is turned on for 2.5 mS, and 2.
The lighting time within one hour is described by repeating 5 mS extinguishing, and the lighting time within one hour is 1800000 mS. According to this, the power consumption per hour in the conventional case is 10 mA × 1H = 10 mAH, whereas the power consumption per hour in the case of the present invention is 10 mA ×
It becomes 0.5H = 5mAH.

Although the present invention has been described above with reference to an embodiment, the dynamic lighting circuit can be incorporated in an integrated circuit to form an integrated circuit.

[0017]

As described above, according to the present invention, the current consumption of the LED for operation display or the illumination of the operation unit / display unit is reduced, and the current consumption of the entire communication device, especially the current consumption at the time of transmission, is suppressed. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a circuit according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of current consumption during transmission and reception according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a lighting time for one hour of an LED according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a current consumption amount during conventional transmission and reception.

[Explanation of symbols]

1 ... register, 2 ... transmission / reception timing generation unit, 3 ...
AND circuit, 4 ... CPU, 5 ... LED, 6 ... Current limiting resistor.

Claims (3)

[Claims] 1. Control of turning on / off an LED mounted on a communication device that performs intermittent transmission / reception, in synchronization with the intermittent transmission / reception timing of the communication device, the LED is turned on during reception and turned off during transmission. A method for dynamically lighting an LED, comprising: 2. A LED light on / off control circuit mounted on a communication device that performs intermittent transmission / reception, a register holding a light on / off command issued by software, and transmission / reception timing for the communication device. A dynamic lighting circuit for an LED, comprising: a timing generation unit that generates a lighting signal; and a logic gate that outputs a lighting signal to the LED when the lighting command held in the register matches the reception timing of the timing generation unit. . 3. An integrated circuit comprising the LED dynamic lighting circuit according to claim 2 built therein and integrated.