KR20050003648A - Power-Saving Mobile Terminal Using After-Image Effect - Google Patents

Abstract

PURPOSE: A power-saving type wireless terminal using after-image effect is provided to minimize power consumption of light emitting diodes by making a user feel that the light emitting diodes are lighted at the same time, thereby extending use time of the wireless terminal. CONSTITUTION: A control unit(14) outputs a predetermined clock frequency for turning on and off a plurality of light emitting diodes at regular intervals. A driving IC(Integrated Chip)(12a) has output ends connected with one side terminals of the light emitting diodes, and a power source output end connected with the other side terminals of the light emitting diodes. The driving IC(12a) sequentially outputs enable signals through the output ends according to the clock frequency and sequentially turns on and off the light emitting diodes.

Description

Power-Saving Mobile Terminal Using After-Image Effect

The present invention relates to a wireless terminal such as a mobile phone or a personal digital assistant (PDA), and in particular, minimizes power consumption of a light emitting diode for a keypad that emits light for easy data input even at night or in a dark place, thereby reducing the use time of the wireless terminal. An extended power saving wireless terminal is provided.

In general, the wireless terminal is provided with a keypad (1) to perform number input or function setting, as shown in Figure 1, the keypad (1) inside the keypad (1) even at night or in a dark place A plurality of light emitting diodes (not shown) are mounted to facilitate the input of a number or setting of a function.

In the case of the folding cellular phone shown in the drawing, when the folder is opened, the power of the battery is applied to each of the light emitting diodes mounted inside the keypad 1 to emit light. That is, as illustrated in FIG. 2, a plurality of light emitting diodes D1 to D12 mounted inside each key button of the keypad 1 are switched by a power output terminal of the battery and an enable signal. It is connected in parallel between Q1), respectively.

Therefore, when the folder of the cellular phone is opened, the power of the battery is applied to each of the light emitting diodes D1 to D12 as the switching element Q1 is switched by the enable signal KEY_LED_EN applied to the switching element Q1 correspondingly. do. Therefore, each of the light emitting diodes D1 to D12 mounted inside each key button emits light so that the user can recognize the position of the corresponding key button of the keypad.

In addition, closing the folder of the cellular phone cuts off the enable signal KEY_LED_EN applied to the switching element Q1, and accordingly switches the switching element Q1 to stop the power supply of the battery to each of the light emitting diodes D1 to D12. do.

However, as described above, when the entire light emitting diodes of the keypad are turned on at the same time to emit light, there is a problem in that power consumption of the light emitting diodes is large. This problem is particularly high in color, such as a high-resolution color liquid crystal display (LCD) and a digital camera is equipped with a large power consumption in the mobile phone has a tendency to shorten the use time of the mobile phone by accelerating the discharge of the battery.

Accordingly, the present invention was invented to solve the above problems, and the LEDs for the keypad are sequentially turned on, but the LEDs are turned on at predetermined time intervals so that all the LEDs are turned on through the afterimage effect. The object of the present invention is to provide a power-saving wireless terminal using the afterimage effect of minimizing the power consumption of the light emitting diode for keypad and extending the use time of the wireless terminal.

1 is a perspective view showing an example of a general wireless terminal,

2 is a view showing a conventional LED driving circuit for a keypad;

Figure 3 is a block diagram showing the configuration of a wireless terminal according to an embodiment of the present invention.

4 is a view showing a light emitting diode driving circuit for a keypad according to the present invention;

Explanation of symbols for main parts of the drawings

11 key input unit 12 light emitting unit

12a: drive IC 13: display unit

14 control unit 15 RF unit

16: voice signal processing unit 17: memory

D: light emitting diode

In order to achieve the above object, the present invention provides a wireless terminal having a keypad on which a plurality of light emitting diodes are mounted: outputting a predetermined clock frequency for turning off the light emitting diodes at intervals of 0.03 seconds. A controller; One terminal of the light emitting diode is connected to an output terminal, the other terminal of the light emitting diode is connected to a power output terminal, and an enable signal is sequentially output through each output terminal according to the clock frequency of the controller to sequentially output the light emitting diode. It is characterized by including a drive IC for turning on and off.

Therefore, only one light emitting diode is actually lit at every moment, but the afterimage effect makes the user feel as if all the light emitting diodes are lit at the same time.

In addition, the driving IC is a CMOS IC that operates by flip-flop.

The clock frequency may be generated from a controller by a software program.

The clock frequency may be a sleep frequency output from a controller in a sleep mode of a wireless terminal.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram schematically showing the configuration of a mobile phone which is a wireless terminal according to an embodiment of the present invention. The present embodiment will be described with reference to a mobile phone among wireless terminals, but is not limited thereto.

Referring to FIG. 3, the RF unit 15 performs a radio processing of signals transmitted and received between the base station and the terminal. For example, the RF unit 15 shifts a frequency band of a baseband transmission signal to a high frequency for wireless output, amplifies it, and wirelessly outputs the antenna to the base station through the antenna ANT, and also receives through the antenna ANT. The high frequency signal is shifted to the baseband frequency band.

On the other hand, the control unit 14 demodulates the radio signal, and transmits the demodulated signal to the RF unit 15. The controller 14 performs a modulation / demodulation operation in a manner preset for mobile communication. For example, the controller 14 may perform a CDMA modulation / demodulation operation such as channel coding / decoding and orthogonal code / decoding.

The control unit 14 basically controls the overall operation of the terminal based on the control program data stored in the memory 17. The control unit 14 may also be referred to as a so-called MSM chip as already known.

In addition, the voice signal processor 16 encodes a voice signal input through a microphone MIC according to an operation mode and transmits the voice signal to the controller 14 or to a voice memory (not shown) under the control of the controller 14. You can also save. In addition, the voice signal processor 16 may decode the demodulated voice signal through the controller 14 and output the decoded voice signal through the speaker SPK.

In general, the voice signal processor 16 includes an analog circuit such as an amplifier and a filter, and a firmware module including an analog / digital conversion circuit, a digital / analog conversion circuit, and a voice compression / extension module.

On the other hand, the memory 17 is divided into a ROM region in which control program data for controlling the operation of the terminal is stored, and a RAM region in which data generated during the terminal control operation is temporarily stored, and is controlled by the controller 14. .

The display unit 13, which is one of the user interface units, displays text data generated by the controller 14, a background screen, and the like. In addition, the key input unit 11, which is another user interface unit, includes a plurality of numeric keys and a plurality of function keys for number input. When each key button is pressed, key data corresponding to the corresponding key button is generated to generate the control unit 14. Is delivered.

In addition, the light emitting unit 12 is composed of a plurality of light emitting diodes mounted on the inside of each key button and a driving IC for turning on / off the light, and the driving IC operates according to a clock signal output from the control unit 14. Each light emitting diode is sequentially turned on / off according to the output signal of the driving IC.

That is, as illustrated in FIG. 4, the output terminals P0 to CMOS ICs operating as flip-flops, in which the anode terminals of the plurality of light emitting diodes D0 to D9 mounted inside each key button of the keypad, are driving ICs 12a. P9), respectively, and the cathode terminals of the light emitting diodes D0 to D9 are connected to the power supply output terminal Vcc of the driving IC 12a.

In addition, a clock signal is applied from the control unit 14 to the clock terminal CLOCK of the driving IC 12a. The clock signal is generated through a software program and uses a clock source of the MSM output through the GIPO terminal of the MSM. .

In this case, since the human perception speed is 0.03 seconds, the light emitting diodes D0 to D9 should be turned off at intervals of 0.03 seconds to show the afterimage effect. Therefore, when one LED is turned on, a clock frequency of 30 Hz or more is required, and when the keypad is composed of 10 key buttons, 30 Hz x is turned on to turn on 10 LEDs corresponding to each key button within 0.03 seconds. A clock frequency of 10 = 300 Hz or higher is required.

Next will be described in detail the operation method of the power-saving wireless terminal according to the present invention configured as described above.

First, when a user opens a folder for use of the wireless terminal, the control unit 14 recognizes the opening of the folder through a conventional method. When the folder is opened in this manner, the control unit 14 applies a predetermined clock frequency generated through the software program to the clock terminal CLOCK of the driving IC 12a of the light emitting unit 12 through the GPIO terminal.

Accordingly, the driving IC 12a, which is a CMOS IC operating in a flip-flop, sequentially outputs an enable signal of a logic level low through each output terminal P0 to P9. The light emitting diodes D0 to D9 mounted on the inner side thereof are turned on sequentially. At this time, if the keypad consists of ten, the enable signal is output at intervals of 300 Hz through the respective output terminals P0 to P9 of the driver IC 12a, so that each light emitting diode D0 to D9 also has an interval of 300 Hz. Will be turned off.

Therefore, since all of the light emitting diodes D0 to D9 are turned on at intervals of 0.03 seconds, only one light emitting diode is turned on at every moment, but the afterimage effect allows the user to turn on all the light emitting diodes D0 to D9 at the same time. I feel it. At this time, the power consumption of the driving IC (12a) to turn off the light emitting diodes (D0 ~ D9) is very weak compared to the power consumption consumed by the lighting of all the light emitting diodes (D0 ~ D9), the overall consumption of the wireless terminal Power can be reduced.

In the above embodiment, the clock source of the MSM, which is generated separately through a software program and output through the GIPO terminal of the MSM, is used. However, a sleep frequency of 32.768 KHz output from the MSM for the sleep mode of the wireless terminal is output. You may use.

As described above, according to the present invention, only one light emitting diode is actually turned on at every moment as the LEDs of the keypad of the wireless terminal are sequentially turned on at intervals of 0.03 seconds. You feel as if it is lit. Therefore, since the power consumption of the light emitting diode for the keypad can be minimized, the use time of the wireless terminal can be extended.

Claims (5)

In a wireless terminal having a keypad equipped with a plurality of light emitting diodes D0 to D9 therein: A controller 14 for outputting a predetermined clock frequency for turning on and off the light emitting diodes D0 to D9 at regular intervals; One terminal of the light emitting diodes D0 to D9 is connected to the output terminals P0 to P9, and the other terminal of the light emitting diodes D0 to D9 is connected to a power output terminal Vcc. The afterimage effect is characterized in that it comprises a driving IC (12a) for sequentially outputting the enable signal through each output terminal (P0 ~ P9) according to the clock frequency to turn on the light emitting diodes (D0 ~ D9) sequentially Power saving wireless terminal. The power saving type wireless terminal of claim 1, wherein the controller 14 outputs a clock frequency for turning off the light emitting diodes D0 to D9 at intervals of 0.03 seconds. 2. The power saving type wireless terminal according to claim 1, wherein the driving IC (12a) is a CMOS IC operating by flip-flop. 4. The power saving type wireless terminal according to claim 1, wherein the clock frequency is generated from a control unit (14) by a software program. The power saving type wireless terminal according to claim 1 or 3, wherein the clock frequency is a sleep frequency output from the control unit (14) in the sleep mode of the wireless terminal.