Electronic shelf label, electronic shelf label system, and electronic shelf label method

1. An electronic shelf label system including a control device and a plurality of terminals, the control device comprising:

a power supply unit configured to provide driving power to the plurality of terminals;

a communication interface configured to provide a display signal to the plurality of terminals;

a terminal selection unit configured to select a terminal to be controlled among the plurality of terminals; and

a controller configured to control the terminal selection unit so as to select the terminal to be controlled and generate the display signal,

wherein each terminal of the plurality of terminals comprises:

a display unit configured to output an image based on the display signal and a driving voltage; and

a circuit unit including a driving power reception unit that generates the driving voltage based on the driving power, and configured to provide the driving voltage to the display unit when a terminal to be controlled by the terminal selection unit is selected,

wherein the circuit unit comprises:

a low pass filter configured to output a direct current (DC) voltage based on a pulse width modulation (PWM) signal;

a driving selection unit configured to output a selection voltage based on the DC voltage and a plurality of reference voltages;

a driving switch configured to provide the driving voltage to the display unit based on the selection voltage; and

a setup switch configured to transfer the selection voltage corresponding to the terminal to be controlled to the driving switch;

wherein the driving power reception unit generates reference power based on the driving power,

wherein the driving selection unit comprises a voltage division unit and a selection voltage generation unit,

wherein the voltage division unit generates the plurality of reference voltages by voltage division based on the reference power, and

wherein the selection voltage generation unit generates the selection voltage based on the DC voltage and the reference voltages.

2. The electronic shelf label system according to claim 1 , wherein the terminal selection unit provides a pulse width modulation (PWM) signal to the plurality of terminals so as to select the terminal to be controlled.

3. The electronic shelf label system according to claim 2 , wherein the terminal selection unit selects the terminal to be controlled by setting a duty ratio of the PWM signal.

4. An electronic shelf label method comprising:

setting a setup switch of a plurality of terminals;

supplying, by a control device, power to the plurality of terminals;

providing, by the control device, a pulse width modulation (PWM) signal corresponding to a terminal to be controlled to the plurality of terminals;

driving power of the terminal to be controlled, based on the PWM signal;

providing, by the control device, a display signal to the plurality of terminals; and

outputting an image to the terminal to be controlled, based on the display signal,

wherein the providing the PWM signal corresponding to the terminal to be controlled to the plurality of terminals comprises providing, by the control device, a PWM signal having a duty ratio set to each terminal to be controlled to the plurality of terminals,

wherein the plurality of terminals comprises a circuit unit configured to provide the driving voltage to the display unit when the terminal to be controlled by the control device is selected, and

wherein the circuit unit comprises:

a driving power reception unit configured to generate a driving voltage based on driving power provided by the control device;

a low pass filter configured to output a direct current (DC) voltage based on the PWM signal;

a driving selection unit configured to output a selection voltage based on the DC voltage and one or more reference voltages;

a driving switch configured to provide the driving voltage to the display unit based on the selection voltage; and

a setup switch configured to transfer the selection voltage corresponding to the terminal to be controlled to the driving switch,

wherein the driving power reception unit generates reference power based on the driving power,

wherein the driving selection unit comprises a voltage division unit and a selection voltage generation unit,

wherein the voltage division unit generates the plurality of reference voltages by voltage division based on the reference power, and

wherein the selection voltage generation unit generates the selection voltages based on the DC voltage and the plurality of reference voltages.

5. The electronic shelf label method according to claim 4 , wherein the setup switch comprises a plurality of switches, and

only the switch set to the terminal to be controlled is turned on, and the other switches are turned off.

6. The electronic shelf label method according to claim 5 , wherein the plurality of switches are reed switches.

7. The electronic shelf label method according to claim 4 , wherein the low pass filter comprises a resistor and a capacitor.

8. The electronic shelf label method according to claim 4 , wherein the selection voltage generation unit comprises:

a plurality of operational amplifiers configured to compare the DC voltage with the reference voltages, generate a high level signal when a level of the DC voltage is higher than a levels of the reference voltages, and generate a low level signal when the level of the DC voltage is lower the levels of the reference voltages; and

a plurality of XOR gates configured to generate the selection voltage when outputs of the operational amplifiers have different levels.