KR200211494Y1 - Apparatus for informing exchange time of filter in water purifier - Google Patents

Abstract

The present invention relates to a device for notifying the replacement time of the water purifier filter, which is attached to one of a plurality of water filters included in the water purifier and measures the amount of water flowing in the water purifier and generates the measured result as a pulse signal. Flow sensor; And warning means electrically connected to the flow sensor, the warning means for counting the pulse signal to indicate when to replace the filters, wherein the warning means includes a portion of a plurality of light emitting elements that generate sound and a buzzer that generates sound. Equipped with the appropriate time to inform the replacement of the filters.

Description

Apparatus for informing exchange time of filter in water purifier}

The present invention relates to an apparatus for detecting the replacement timing of the filters used in the water purifier.

In general, there is a method using a timer as a way to indicate when to replace the filter in the water purifier. The method using the timer refers to a method of checking the life of the filter by displaying the use time of the filter in the existing water purifier as a timer. As described above, in the method of checking the life of the filter using the timer, even when the user does not use the water purifier, the timer displays the replacement time when a predetermined time elapses, thereby reducing the reliability of the filter replacement.

The technical problem to be achieved by the present invention is to provide a device for measuring the amount of water informing the replacement time of the filter.

A brief description of each drawing is provided to more fully understand the drawings, which are incorporated in the detailed description of the invention.

1 is a view showing a filter replacement time warning device of the present invention attached to the faucet and the water purifier and the water purifier.

FIG. 2 is a plan view of the flow sensor shown in FIG. 1.

3 is a side view of the flow sensor shown in FIG. 1.

FIG. 4 shows a first embodiment of the warning means shown in FIG.

FIG. 5 shows a second embodiment of the warning means shown in FIG.

FIG. 6 shows a third embodiment of the warning means shown in FIG.

7 is a block diagram of the controller shown in FIG. 6.

The present invention to achieve the above technical problem,

A flow rate sensor attached to one of a plurality of water purification filters embedded in the water purifier, measuring a quantity of water flowing in the water purifier and generating the measured result as a pulse signal; And warning means electrically connected to the flow sensor, the warning means for counting the pulse signal to indicate when to replace the filters, wherein the warning means includes a portion of a plurality of light emitting elements that generate sound and a buzzer that generates sound. Provides a filter replacement time warning device characterized in that it provides a notification of the replacement time.

Preferably, the flow sensor is a main body; An inlet pipe attached to the main body and into which water flowing in the water purifier flows; An outlet pipe attached to the main body and configured to discharge water introduced into the main body and form an angle of 45 degrees to 135 degrees with the inlet pipe; Rotating means is installed inside the main body and rotates when the water flowing through the inflow pipe is discharged through the outflow pipe while sensing the amount of the outflow water; And a pulse signal generator connected to the rotating means and generating the pulse signal when the rotating means rotates, the number of the pulse signals being proportional to the number of rotations of the rotating device.

Preferably, the pulse signal generator has first and second magnets, wherein the first magnet is attached to the rotating means and the second magnet is installed on the body so that the first magnet is rotated when the rotating means rotates. When one magnet rotates together and the first magnet rotates, the N pole and the S pole of the first magnet cross the N pole and the S pole of the second magnet to generate the pulse signal.

Preferably, the inlet pipe and the outlet pipe are 'U' shaped or at right angles.

Preferably, the light emitting elements are LEDs, and when it is time to replace one of the filters, one of the light emitting elements is turned on, indicating the usage time of the filters.

Preferably, the warning means has a plurality of switches, and when one of the light emitting elements is turned on, resetting one of the switches turns off the turned on light emitting element.

Preferably, the flow sensor is also connected between the filter and the filter.

The warning means

Preferably, the plurality of light emitting devices, the pulse signal and a predetermined power supply voltage are input, the pulse signal is counted, and the corresponding light emitting device among the plurality of light emitting devices is turned off according to a count result of the pulse signal. A microcontroller configured to store a count result of the pulse signal from the microcontroller when the predetermined power supply voltage is disconnected, and a count result of the pulse signal from the microcontroller to correspond to the plurality of light emitting devices. And a buffer for turning on the light emitting elements.

According to the present invention, the manufacturing cost of the filter replacement time warning device is reduced.

The filter replacement time warning device of the present invention measures the amount of water and generates it as a pulse signal, and counts the pulse signal to inform the filter replacement time.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a view showing the filter replacement time warning device 131 of the present invention attached to the faucet 111 and the water purifier 121 and the water purifier 121. Referring to FIG. 1, the replacement time warning device 131 of the present invention includes a flow sensor 133 and a warning means 135.

The faucet 111 supplies tap water to a general household.

The water purifier 121 receives tap water flowing out from the tap 111 through the water supply pipe 123 and removes harmful carcinogens contained in the tap water and supplies purified water to the water purifier user through the intake port 125. A plurality of filters f1 to f5 are built in the water purifier 121, and the filters f1 to f5 serve to purify the tap water. In general, the larger the number of the filters f1 to f5, the better the water purifying function of the water purifier 121 is. However, if the number of the filters f1 to f5 is large, the price of the water purifier 121 is so high that the number of the filters f1 to f5 is selected according to the price and the function of the water purifier 121.

The flow sensor 133 is attached between the filter f4 and the filter f5 and measures the amount of water flowing out of the filter f4 and generates the measured result as an electrical signal. The flow sensor 133 may have the same effect even if it is attached to the inlet of any of the filters f1 to f5.

The warning means 135 is electrically connected to the flow sensor 133 and analyzes the electrical signal to indicate when to replace the filters f1 to f5.

2 and 3 are a plan view and a side view of the flow sensor 133 shown in FIG. 1, respectively. 2 and 3, the flow sensor 133 includes a main body 211, and an inlet pipe 221 and an outlet pipe 231 are attached to the side of the main body 211. Water passing through the filter f4 through the inlet pipe 221 is input to the main body 211, and the water flowing out through the outlet pipe 231 flows into the filter f5. The water flowing out through the flow sensor 133 is purified by the filter f5.

Under the body 211 are means 241, for example screws, for fixing the body 211 to another device.

Inside the main body 211, a rotating device 251 having a plurality of wings 253 is installed. When water is introduced into the main body 211 through the inlet pipe 221, the rotating device 251 rotates. The inlet pipe 221 and the outlet pipe 231 form an angle of 45 degrees to 135 degrees or 'U' shape with each other. In this way, even if a small amount of water is introduced into the inlet pipe 221, the rotary device 251 may rotate to measure the amount of water introduced into the flow sensor 133.

The pulse signal generator 261 is provided inside the main body 211. When the rotating device 251 rotates, the pulse signal generator 261 operates to generate a pulse signal. The pulse signal generator 261 includes first and second magnets 263 and 265. The first magnet 263 is attached to the rotating means 251 and the second magnet 265 is installed in the main body 211. When the rotating means 251 rotates, the first magnet 263 rotates together, and when the first magnet 263 rotates, the N pole and the S pole of the first magnet 263 are N of the second magnet 265. A pulse signal is generated while crossing the pole and the S pole. The pulse signal is transmitted to the warning means 135 via the output lines 271.

If the amount of water input through the inlet pipe 221 is large, the rotational speed of the rotary device 251 is faster, and if the rotational speed of the rotary device 251 is faster, a lot of pulse signals are generated. On the contrary, when the amount of water input through the inlet pipe 221 is small, the rotation speed of the rotary device 251 is slowed down, and when the rotation speed of the rotary device 251 is slowed, less pulse signals are generated. As such, the flow sensor 133 converts the amount of water flowing into the main body 211 into a pulse signal, thereby making it easy to measure the amount of water.

FIG. 4 shows a first embodiment of the warning means 135 shown in FIG. Referring to FIG. 4, the warning means 135 includes a main body 411, and the main body 411 includes a plurality of light emitting devices 421 to 425, for example, light emitting devices (LEDs) and a plurality of switches ( 431-436, the buzzer 441, and the control apparatus 451 are provided.

The plurality of light emitting devices 421 to 425 emit light when a predetermined voltage is applied. The number of light emitting elements 421 to 425 is provided at least equal to the number of filters f1 to f5.

The switches 431 to 435 are used to reset the turned on light emitting elements 421 to 425 when the light emitting elements 421 to 425 are turned on. One switch is provided in each light emitting element. When the user presses a switch when the light emitting devices 421 to 425 are turned on, the light emitting devices 421 to 425 which are turned on are reset or turned off. In addition, the switch 436 is electrically connected to the buzzer 441, and the buzzer 441 does not generate a warning sound when the switch 436 is reset when the buzzer 441 generates a warning sound. Only the buzzer 441 or only the light emitting elements 421 to 425 may be installed in the warning means 135, or all of them.

The control device 451 is electrically connected to the switches 431 to 435, the light emitting elements 421 to 425, and the buzzer 441, and is also connected to the power plug 461 and the control lines 271. The controller 451 controls the operation of the switches 431 to 435, the light emitting elements 421 to 425, and the buzzer 441 by receiving a power voltage through the power plug 461 or through a battery (not shown). do. As the power supply voltage, a commercial voltage such as 110 volts or 220 volts may be used, or a voltage supplied from a battery may be used. The control apparatus 451 has a count function which counts a pulse signal. Therefore, when a pulse signal is generated from the flow sensor 133, the control device 451 counts the number of pulses of the pulse signal and operates the light emitting elements 421 to 425 and the buzzer 441 according to the number of counts. Let's do it.

The water purifier user can know when to replace the filters f1 to f5 through the light emitting elements 421 to 425 and the buzzer 441. That is, when the control device 451 is programmed to operate the light emitting elements 421 to 425 and the buzzer 441 in accordance with the replacement timings of the filters f1 to f5, the replacement timing of the filters f1 to f5 may be reduced. Each time the light emitting elements 421 to 425 and the buzzer 441 operate. The replacement timing of the filters f1 to f5 is determined according to the amount of water flowing in the water purifier 121. For example, assuming that the replacement time of the filter f1 is when the water purifier user uses 1000 liters of water, the control device 451 counts the pulse signal generated from the flow sensor 133 and the inside of the water purifier 121. Measure the amount of water flowing.

Then, when 1000 liters of water flows out from the water purifier 121, the count is stopped and the control device 451 emits the light emitting element 421 and simultaneously sounds the buzzer 441. The water purifier user then replaces the filter f1 and resets the switch 431. Then, the light emitting element 421 is turned off, and the buzzer 441 no longer generates a warning sound. The light emitting device 421 remains turned on unless the user resets the switch 431, and the buzzer 441 continues to ring or generates a warning sound every predetermined time. The operation of the buzzer 441 depends on how the controller 451 is programmed. The operating time is thus determined.

FIG. 5 shows a second embodiment of the warning means shown in FIG. Referring to FIG. 5, the warning means 135 includes a main body 511, which includes a plurality of displays 521 to 525, 531 to 535, and a plurality of light emitting elements 541, such as LEDs. Emitting Devices), a plurality of switches 431 to 436, a buzzer 441 and a controller 451.

Displays 521 to 525 indicate the types of filters built into the water purifier. For example, the display 521 is the first filter f1, the display 522 is the second filter f2, the display 523 is the third filter f3, and the display 524 is the fourth filter ( f4), the display 525 displays the fifth filter f5. The number of displays 521 to 525 varies depending on the number of filters f1 to f5.

The displays 531 to 535 are elements for informing the exchange of the filters f1 to f5. That is, when some of the light emitting devices in the 8th and 10th columns of the light emitting devices 541 emit light, it is time to replace the corresponding filter.

The plurality of light emitting elements 541 emit light when a predetermined voltage is applied. The light emitting elements 541 are allocated a predetermined number, for example, 10 per filter, and each light emitting element indicates when to use the corresponding filter. For example, if the first filter f1 is to be replaced when the water of 1000 liters is purified, the light emitting elements of the first row emit light one by one starting from the first column whenever 100 liters of water are purified. That is, if 100 liters of water is purified, the light emitting elements of the first row are emitted, and if 200 liters of water are purified, the light emitting elements of the first and second rows are emitted, and if 1000 liters of water is purified, the first to tenth emission is emitted. All the elements emit light.

The light emitting method may be configured differently. For example, there is also a method in which 100 liters of water are emitted one by one starting from the light emitting element in the first row. That is, when the first 100 liters of water is purified, only the light emitting elements in the first row are emitted. When the 200 liters of water are purified, the light emitting elements in the first row are turned off, and only the light emitting elements in the second row are emitted. Thus, when 1000 liters of water is purified, only the light emitting elements of the tenth row are emitted.

When the light emitting elements of the tenth row emit light, a buzzer sounds to inform voice of the replacement time of the filters f1 to f5.

A predetermined number of light emitting elements of the light emitting elements 541 allow light to be emitted in a predetermined color, for example red, in order to warn in advance of when to replace the filters. For example, the light emitting elements in the eighth to tenth columns cause the light to emit red when they emit light. Therefore, the water purifier user is informed in advance when to replace the filters f1 to f5. At this time, the light emitting elements in the 1st to 7th rows are emitted in a predetermined color, for example, green, to distinguish them from the light emitting elements in the 8th to 10th rows.

The switches 431 to 435 are used to reset the turned on light emitting elements 421 to 425 when the light emitting elements 421 to 425 are turned on, and one switch is provided in one filter. If the switch is reset when the light emitting elements 421 to 425 are turned on, the light emitting elements 421 to 425 are reset, that is, off. In addition, the switch 436 is electrically connected to the buzzer 441, and the buzzer 441 does not generate a warning sound when the switch 436 is reset when the buzzer 441 generates a warning sound. Only the buzzer 441 is installed in the warning means 135, Only the light emitting elements 421 to 425 may be provided, or all of them.

The controller 451 is electrically connected to the switches 431 to 435, the light emitting elements 421 to 425, and the buzzer 441. The controller 451 is also connected to the power plug 461 and the control lines 271. The controller 451 receives a power supply voltage through the power plug 461 or through a battery (not shown) to control the operations of the switches 431 to 435, the light emitting devices 541, and the buzzer 441. As the power supply voltage, a commercial voltage such as 110 volts or 220 volts may be used, or a voltage supplied from a battery may be used. The controller 451 has a count function of counting pulse signals. Therefore, when a pulse signal is generated from the flow sensor 133, the controller 451 counts the number of pulses of the pulse signal and operates the light emitting elements 541 and the buzzer 441 according to the number of counts.

The water purifier user can know when to replace the filters f1 to f5 through the light emitting elements 541 and the buzzer 441. That is, if the controller 451 is programmed to operate the light emitting elements 541 and the buzzer 441 in accordance with the replacement timings of the filters f1 to f5, each time the replacement of the filters f1 to f5 is performed, the controller 451 is programmed. The light emitting devices 541 and the buzzer 441 operate.

Since the controller 451 has a memory to store the constant amount of the filters f1 to f5, the light emitting devices 541 are in a state before the power failure when the power voltage is normally supplied again in a state where the power supply is not supplied due to a power failure. It works.

FIG. 6 shows a third embodiment of the warning means shown in FIG. Referring to FIG. 6, the warning means 135 includes a main body 611, which includes a plurality of indicators 621 to 625, 631 to 635, a plurality of light emitting elements 641, and a controller 651. Including All.

The indicators 631 to 635 indicate the types of the filters f1 to f5 built in the water purifier (121 of FIG. 1). For example, the indicator 631 indicates the first filter f1, the indicator 632 indicates the second filter f2, the indicator 633 indicates the third filter f3, and the indicator 634 indicates the fourth filter F1. f4), the indicator 635 displays the fifth filter f5. The number of indicators 631 to 635 also varies depending on the number of filters f1 to f5. The red light emitting device and the green light emitting device are provided inside the indicators 631 to 635, and the replacement of the filters f1 to f5 depending on which one of the indicators 631 to 635 is turned on. The timing is decided. For example, normally, the green light emitting elements of the indicators 631 to 635 are turned on, and when the predetermined filter is replaced, the green light emitting elements of the indicators corresponding to the predetermined filter of the indicators 631 to 635 are turned off. And the red light emitting element is turned on. The red light emitting element and the green light emitting element provided in the indicators 631 to 633 are each configured with one or more numbers.

The indicators 621 to 625 together with the indicators 631 to 635 are elements that indicate when to replace the filters f1 to f5. The light emitting device is provided inside the indicators 621 to 625, and the light emitting devices are normally turned off, and when the predetermined filter is replaced, the light of the indicator corresponding to the predetermined filter among the indicators 621 to 625 is emitted. The device is turned on. The colors of the indicators 621 to 625 are determined according to the color of the light emitting elements provided in the indicators 621 to 625. The water purifier user knows when to replace the filters f1 to f5 by looking at the light color of the indicators 621 to 625, 631 to 635.

A plurality of light emitting devices 641, for example, a light emitting device (LED) emits light when a predetermined voltage is applied. The light emitting elements 641 are allocated a predetermined number, for example, 10 per filter, and each light emitting element informs the usage time of the corresponding filter. That is, the light emitting devices are normally turned on in a predetermined color, for example, green, and are turned off one by one every time the amount of purified water increases. For example, if the first filter f1 needs to be replaced when water is purified to 1000 liters of water, the light emitting elements of the SED indicator 631 are turned off one by one starting from the tenth light emitting element every time 100 liters of water is purified. In other words, if 100 liters of water is purified, the 10th light emitting device is turned off.If 200 liters of water is purified, the 9th light emitting device is turned off. Is off.

The controller 651 receives a commercial voltage supplied to a general home through a power plug 661, and receives indicators 621 by receiving a pulse signal generated by the flow sensor 133 of FIG. 1 through the control line 271. To 625,631 to 635 and the light emitting elements 641 are controlled. The controller 641 will be described in detail with reference to FIG. 7.

7 is a block diagram of the controller shown in FIG. 6. Referring to FIG. 7, the controller includes a microcontroller 711, a memory 721, a buffer 751, drivers 741 to 746, and switches SW1 to SW8. ).

The microcontroller 711 operates by receiving a commercial voltage supplied to a general home through a power plug 661, and receives a pulse signal generated by the flow sensor 133 of FIG. 1 through the control line 271. The microcontroller 711 counts a pulse signal transmitted through the control line 271 to determine on / off of the light emitting elements 641, and stores the counted result in the memory 721 during a power failure. The switch SW1 is normally turned off. When the switch SW1 is turned on, the microcontroller 711 receives a signal input from the driver 746 through the line L21. That is, when the user of the water purifier comes to replace the predetermined filter, the water purifier user exchanges the predetermined filter while the corresponding switch among the switches SW1 and the switches SW3 to SW8 is turned on. When the replacement of the predetermined filter is completed, the water purifier user turns off the switch SW1 and the corresponding switch.

The switch SW2 indicates whether a predetermined water purifier is used among the filters F1 to f5. For example, when the UV filter f3 is used, the switch SW2 is turned on.

The microcontroller 711 transfers the count result of the pulse signal to the buffer 751. The buffer 751 latches the input data and delivers the data to the drivers 741 to 746. The drivers 741 to 745 receive the output of the buffer 751 and output a current required to turn on the light emitting elements 641 to 645. The light emitting elements 641 to 645 are turned on by the drivers 741 to 745.

The light emitting devices 641 to 645 have a high level of output voltages of the drivers 741 to 745, for example, 5 volts, and the output voltage VO of the microcontroller 711 has a low level. If the output voltage VO of the microcontroller 711 is at a high level, the light emitting devices 641 to 645 are turned off regardless of the output voltages of the drivers 741 to 745. Although the output voltage VO is at the low level, the light emitting elements 641 to 645 are turned off when the output voltages of the drivers 741 to 745 are at the low level. Therefore, while voltage is supplied to the microcontroller 711 through the power plug 461, the buffer 751 applies voltage to the light emitting elements 641 to 645 through the drivers 741 to 745, thereby emitting light. When the 641 to 645 are turned on and some of the light emitting elements 641 to 645 are turned off, the microcontroller 711 applies a low level voltage to the corresponding light emitting device to turn off the desired light emitting device.

The switches SW3 to SW8 are used to turn off corresponding light emitting elements when a predetermined one of the filters f1 to f5 is replaced. The switches SW3 to SW8 correspond to one of the light emitting elements 641 to 645, respectively, and the switch SW8 is used as a safety device. That is, when the first filter f1 is replaced, the switch SW3 is turned on so that a high voltage is applied to some of the light emitting elements 641, so that some of the light emitting elements are turned off. In this state, the switch SW8 is also turned on so that the exchange state of the filter f1 can be recognized more reliably from the outside.

The microcontroller 711 is connected to the light emitting elements 641 to 645 through the lines L1 to L6. As such, in order for the microcontroller 711 to be connected to all the light emitting elements 641 to 645, the microcontroller 711 should have many output terminals (80 in FIG. 7). Because of the limited output terminals, it is difficult for the microcontroller 711 to be connected one-to-one to the light emitting elements 641 to 645. Accordingly, the output lines L1 of the microcontroller 711 are connected to the output lines L2 to L6 of the light emitting elements 641 to 645 while being alternately connected to each other so that the number of output terminals of the microcontroller 711 is reduced to a predetermined number (Fig. 7). Is 16). At this time, the buffer 751 is also connected to the drivers 741 to 745 while switching. Here, when the time for which the output line L1 of the microcontroller 711 is connected to the output lines L2 to L6 of the light emitting elements 641 to 645 once is shorter than (1/30) seconds, the observation is performed due to the afterglow effect. In the human eye, the light emitting elements 641 to 645 are kept on. In the same manner, the output line L11 of the buffer 751 is also connected to the input lines L12 to L17 of the drivers 741 to 745.

In Fig. 7, the number of light emitting elements 641 to 645 is 16, respectively, two for the indicators 621 to 625 and four for the indicators 631 to 635, respectively (two are red light emitting elements). For example, two green light emitting elements are installed, and the number of the light emitting elements can be adjusted according to characteristics.

The best embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached utility model registration claims.

As described above, since only one filter replacement time warning device of the present invention is attached to the inside of the water purifier 121, the manufacturing cost of the filter replacement time warning device is low, so that the user of the water purifier may use the filter replacement time warning device at a low cost. In addition, the filter replacement time warning device of the present invention measures the amount of water and informs the replacement time of the filters f1 to f5, thereby allowing the water purifier user to replace the filters f1 to f5 at an appropriate time. Therefore, the life of the water purifier 121 is long and the water purifier user can always receive clean water from the water purifier 121.

Claims (11)

A flow rate sensor attached to one of a plurality of water purification filters embedded in the water purifier, measuring a quantity of water flowing in the water purifier and generating the measured result as a pulse signal; And Warning means electrically connected to the flow sensor and counting the pulse signal to indicate when to replace the filters, The warning means And a buzzer for generating sound and some of a plurality of light emitting devices for generating light to notify the replacement time of the filter. The method of claim 1, wherein the flow sensor main body; An inlet pipe attached to the main body and into which water flowing in the water purifier flows; An outflow pipe attached to the main body and outflowing outflow of water introduced into the main body, the outlet pipe having an angle of 45 degrees to 135 degrees with the inflow pipe; Rotating means is installed inside the main body and rotates when the water flowing through the inflow pipe is discharged through the outflow pipe while sensing the amount of the outflow water; And A pulse signal generator connected to the rotating means and generating the pulse signal when the rotating means rotates, And the number of pulse signals is proportional to the number of rotations of the rotating device. The method of claim 2, The pulse signal generator has first and second magnets, wherein the first magnet is attached to the rotating means and the second magnet is installed on the main body so that the first magnet rotates together when the rotating means rotates. And when the first magnet rotates, the pulse signal is generated while the N pole and the S pole of the first magnet cross the N pole and the S pole of the second magnet. The method of claim 2, The filter replacement time warning device, characterized in that the inlet pipe and the outlet pipe forms a 'U' shape. The method of claim 2, The filter replacement time warning device, characterized in that the inlet pipe and the outlet pipe forms a right angle. The method of claim 1, And the light emitting elements are LEDs. The method of claim 1, And a light emitting element corresponding to the light emitting elements when the one of the filters is replaced. The method of claim 1, And the warning means has a plurality of switches, and when one of the light emitting elements is turned on, resetting one of the switches turns off the turned on light emitting element. The method of claim 1, And the flow sensor is connected between the filter and the filter. The method of claim 1, And the light emitting elements inform the use time of the filters. The method of claim 1 wherein the warning means The plurality of light emitting devices; A microcontroller configured to input the pulse signal and a predetermined power supply voltage, count the pulse signal, and turn off a corresponding light emitting device among the plurality of light emitting elements according to a count result of the pulse signal; A memory configured to receive and store a count result of the pulse signal from the microcontroller when the predetermined power supply voltage is disconnected; And And a buffer for receiving a count result of the pulse signal from the microcontroller and turning on corresponding light emitting elements among the plurality of light emitting elements.