KR102184915B1 - Sticker type cleaning device and method of operating the same - Google Patents

Abstract

A sticker type cleaning device capable of removing droplets by attaching to other devices is disclosed. The sticker-type cleaning device includes a substrate, at least one electrode arranged on the substrate, an insulating film arranged on the electrode, and an adhesive layer arranged on a side opposite to a side surface of the substrate on which the electrode is arranged. Here, the cleaning device can be attached to another device through the adhesive layer, and when a specific voltage is applied to the electrode, droplets formed on the surface of the cleaning device are moved and removed.

Description

Sticker type cleaning device and its operation method {STICKER TYPE CLEANING DEVICE AND METHOD OF OPERATING THE SAME}

The present invention relates to a sticker-type cleaning device for removing droplets formed on a surface of a vehicle or a camera, and a method of operating the same.

According to the recent electrification of auto parts and the spread of smart cars, HUD (Head-up-display) technology that displays various driving information on the vehicle windshield, and furthermore, turns the vehicle windshield into a transparent display. Efforts to replace are underway.

Accordingly, the development of a cleaning technology capable of efficiently removing foreign substances such as rainwater or dust generated in the windshield of a vehicle or a transparent display to replace the same has become important.

Currently, most vehicles generally use a wiper to remove contaminants. However, when the wiper is driven, it repeatedly moves on the windshield and not only continues to obstruct the driver's vision, but also the area that can be removed is limited in the form of an arc. In addition, when the wiper is old, friction noise occurs and the removal ability decreases, so there is a problem that the wiper must be replaced regularly.

In addition, devices such as cameras are exposed to the external environment as they are. Therefore, water adheres to the camera surface when it rains or gets wet with water. In this case, since there is no separate function to remove the water, the camera performance is inevitably deteriorated.

In addition, in order to keep the field of view of the small camera clean, droplets generated on the lens surface must be immediately removed. If the cleaning device is continuously operated for this purpose, unnecessary power consumption is generated and the life of the cleaning device is reduced.

Accordingly, there is a need for a cleaning device capable of removing droplets with a small power, particularly a cleaning device having strong durability, and a droplet detection technology that is driven only when the cleaning device detects droplets generated on the lens surface.

KR 10-1653807 B

The present invention is to solve the problems of the prior art described above, and to provide a technique for removing droplets, dust, or frost formed on glass such as a vehicle or a camera by applying an electrowetting technique.

In addition, the present invention is to provide a camera droplet detection apparatus and method for detecting droplets generated on the surface of the camera cover glass using the impedance of the camera cover glass or an image captured by the camera.

In addition, the present invention provides a cleaning apparatus and method for removing conductive droplets formed on the surface using the principle of electrowetting-on-dielectric, and removing non-conductive droplets formed on the surface using the principle of dielectrophoresis. I want to provide.

Furthermore, the present invention is to provide a cleaning device including a hydrophobic film having strong durability.

In addition, the present invention is to provide a sticker-type cleaning device that is attached to another device without a cleaning function to remove droplets as a sticker-type cleaning device, and a method of operating the same.

In order to achieve the above object, a sticker-type cleaning device according to an embodiment of the present invention includes a substrate; At least one electrode arranged on the substrate; An insulating film arranged on the electrode; And an adhesive layer arranged on a side surface opposite to a side surface of the substrate on which the electrodes are arranged. Here, the cleaning device can be attached to another device through the adhesive layer, and when a specific voltage is applied to the electrode, droplets formed on the surface of the cleaning device are moved and removed.

A sticker-type cleaning device according to another embodiment of the present invention includes a substrate made of a flexible material; At least one electrode arranged on the substrate; An insulating film arranged on the electrode; And an adhesive layer arranged on a side surface opposite to a side surface of the substrate on which the electrodes are arranged. Here, the cleaning device removes droplets on the surface of the cleaning device using electrowetting and dielectrophoresis techniques, and the cleaning device can be attached to another device having a curved structure through the adhesive layer.

According to an embodiment of the present invention, it is possible to provide a smart self-cleaning glass for a vehicle capable of quickly and effectively removing contaminants such as rainwater, dust, and frost generated on a vehicle windshield.

In addition, since the grain of the electrode in the cleaning device is the same as the moving direction of the droplet, the removal speed of the droplet may be faster and the voltage applied to the electrode may be lowered.

In addition, since there is no need to periodically replace the cleaning device (structure), the risk of an accident can be significantly lowered.

In addition, it is possible to secure a view of the vehicle even in an environment such as bad weather, thereby helping the driver to drive safely, and it can contribute to the improvement of the vehicle's fuel economy by reducing the weight and air resistance of the vehicle.

The camera droplet detection apparatus and method according to an embodiment of the present invention may detect droplets generated on the surface of the camera cover glass using the impedance of the camera cover glass or an image captured by the camera.

The cleaning apparatus and method according to an embodiment of the present invention can remove not only conductive droplets formed on the surface but also non-conductive droplets using the electrowetting principle and the dielectrophoresis principle.

In addition, by applying electrowetting technology and dielectrophoresis technology, it has the advantage of fast response speed and low energy consumption. Accordingly, various fields such as vehicle windshield and image sensors of IoT devices as well as small cameras for vehicles or mobiles Can be applied to or used in

In addition, since the hydrophobic film used in the cleaning apparatus of the present invention contains a fluorine-based material and a silane-based material, the hydrophobic film can have a strong durability compared to the conventional hydrophobic film.

Moreover, the cleaning device of the present invention can be attached to other devices including the contact layer, and thus can be attached to other devices without a cleaning function to remove droplets.

1 is a diagram showing the configuration of a cleaning device according to an embodiment of the present invention.
2 and 3 are diagrams showing the configuration of a cleaning device according to an embodiment of the present invention.
4 is a flow chart showing a cleaning process according to an embodiment of the present invention.
5 is a flow chart showing a cleaning process according to another embodiment of the present invention.
6 is a diagram illustrating an actual cleaning process of a cleaning device according to another embodiment of the present invention.
7 is an actual use scene of a cleaning device according to an embodiment of the present invention.
8 is a diagram illustrating a droplet removal process of a cleaning device according to an embodiment of the present invention.
9 is a diagram showing a schematic structure of a cleaning device according to an embodiment of the present invention.
10 is a view showing an electrode pattern according to an embodiment of the present invention.
11 is a diagram illustrating a flow of a droplet when a droplet is removed according to an embodiment of the present invention.
12 is a diagram illustrating a change in a droplet contact angle when a droplet is removed according to an embodiment of the present invention.
13 is a diagram showing the result of a droplet removal experiment.
14 is a diagram schematically illustrating an electrode of a cleaning device according to another embodiment of the present invention.
15 is a diagram illustrating a droplet removal process of a cleaning device according to an embodiment of the present invention.
16 is a view showing an electrode pattern according to an embodiment of the present invention.
17 is a diagram illustrating a flow of a droplet when a droplet is removed according to an embodiment of the present invention.
18 is a diagram illustrating a change in a droplet contact angle when a droplet is removed according to an embodiment of the present invention.
19 is a view showing a flow of droplets when a droplet is removed according to another embodiment of the present invention.
20 and 21 are diagrams showing the droplet removal experiment results.
22 is a diagram schematically illustrating a configuration of a camera droplet detection apparatus according to an embodiment of the present invention.
23 is a diagram illustrating a change in impedance of a camera cover glass according to the presence or absence of droplets.
24 is a diagram illustrating an example of an image captured when droplets are generated on a camera cover glass.
25 is a flowchart illustrating a camera droplet detection method according to an embodiment of the present invention.
26 is a flowchart illustrating a camera droplet detection method according to another embodiment of the present invention.
27 is a view showing a cleaning device according to an embodiment of the present invention.
28 is a diagram illustrating an electrode pattern of a cleaning device according to an embodiment of the present invention.
29 is a diagram schematically illustrating a configuration of a cleaning device according to an embodiment of the present invention.
30 to 33 are views for explaining a cleaning device according to an embodiment of the present invention.
34 is a flow chart showing a cleaning method according to an embodiment of the present invention.
35 is a diagram schematically showing the structure of a cleaning device according to an embodiment of the present invention.
36 is a diagram schematically illustrating a process of manufacturing a hydrophobic film according to an embodiment of the present invention.
37 is a cross-sectional view showing a sticker-type cleaning device according to another embodiment of the present invention.
38 and 39 are views illustrating a process in which a droplet is removed.

The singular expression used in the present specification includes a plural expression unless the context clearly indicates otherwise. In the present specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional elements or steps. In addition, terms such as "... unit" and "module" described in the specification mean units that process at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

The present invention relates to a cleaning device capable of self-removing droplets, dust, frost, etc. of liquid such as rainwater and fog, and a method for removing droplets therein. The cleaning device may be a single device or may be a device that is combined with other devices.

According to an embodiment, the cleaning device may be a device including external glass, for example, a vehicle camera, a digital camera, a mobile camera, an image sensor of the Internet of Things, and the like. Of course, the cleaning device is not limited to a camera, and includes all devices in which droplets need to be removed.

According to another embodiment, the cleaning structure may correspond to a windshield of a vehicle.

Of course, the cleaning structure is not limited to a camera or a vehicle window as long as droplets can be removed, and may be variously modified.

Such a cleaning device is exposed to an external environment, and as a result, droplets such as rainwater may adhere to the surface of the cleaning device.

Conventionally, when rainwater or the like adheres to a glass surface such as a camera, there is no way to remove rainwater or the like, so the performance of the camera is inevitably deteriorated. In particular, in the case of a vehicle that controls a specific function of a vehicle based on an image of a camera, a decrease in image quality due to droplets may cause a vehicle accident.

In addition, in the related art, since rainwater or the like was removed using a wiper when the front windshield of the vehicle is attached, the risk of an accident may increase when the wiper is delayed.

Therefore, it is necessary to remove the droplet as soon as the droplet is attached to the surface, and the present invention proposes a cleaning device capable of removing the droplet immediately when the droplet is attached to the surface.

In addition, it is a technology that can substitute a wiper capable of removing the droplet as soon as the droplet adheres to the surface without being replaced. The present invention proposes a cleaning structure capable of lowering the risk of accidents while removing the droplets immediately when the droplets are attached to the surface.

According to an embodiment, the cleaning device removes droplets, dust, or frost using electrowetting and dielectrophoresis techniques. In particular, the cleaning device may remove droplets, dust, or frost from a surface through a method of applying a specific voltage to an electrode. In particular, the cleaning device can remove both droplets and micro droplets, and can easily remove droplets regardless of the pH and viscosity of the droplets. Here, the method of applying the specific voltage includes an AC method in which a specific voltage is applied to all electrodes at once, and a DC method in which a specific voltage is sequentially applied to the electrodes.

In another aspect, the cleaning device may remove droplets by generating vibrations on the surface. When vibration is generated on the surface of the cleaning device, the adhesive force between the droplet and the surface is weakened, so that the droplet may be removed by moving in the direction of gravity. For example, the surface of a cleaning device such as a vehicle camera is inclined in the direction of gravity, so when the adhesion between the droplet and the surface is weakened, the droplet moves in the direction of gravity due to gravity, and as a result, the droplet It can be removed from the cleaning device.

From a vehicle control point of view, rainwater may adhere to the surface of the camera as it rains. In this case, when the driver inputs a rainwater removal command (droplet removal command), the controller (not shown) may remove the rainwater by applying a specific voltage to an electrode formed on the surface of the camera. The specific voltage may be supplied to the camera from a power source, for example a vehicle battery. Meanwhile, the control unit may be one of the electronic control units (ECUs) of the vehicle.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, for convenience of explanation, the object to be removed will be limited to droplets, but is not limited to droplets, and dust and frost may be removed as well as droplets (including fine droplets).

1 is a diagram showing the configuration of a cleaning device according to an embodiment of the present invention.

The cleaning device 100 according to an embodiment of the present invention may be applied to a vehicle windshield or a camera as shown in FIG. 1.

In the cleaning device 100, a plurality of electrodes separated from each other are patterned on a microchip manufactured by a MEMS process.

As an embodiment of cleaning, the cleaning device 100 may change the surface tension of a droplet by applying a voltage to each electrode in different DC voltage conditions (high, ground).

In this case, as shown in FIG. 1, the droplet moves in the direction of the electrode to which the ground voltage and the high voltage are applied (eventually, the outer side of the substrate (vehicle glass)).

As another example of cleaning, the cleaning device 100 may change the surface tension of the droplet by applying an AC voltage, for example, a low frequency AC voltage, to the electrode to cause the droplet to vibrate. However, the AC voltage is not limited to a low frequency AC voltage.

For example, since the vehicle glass has a predetermined inclination with respect to the plane, the droplets vibrate and move downwards (eventually the outside of the vehicle glass).

Specifically, when the cleaning device 100 applies a low-frequency alternating voltage of several hundred Hz or less, for example, 50 Hz to the electrode, the area of the droplet touching the surface of the cleaning device 100 continuously changes (shakes), causing As a result of the vibration, the adhesion force between the droplet and the surface of the cleaning device 100 continuously decreases, and the droplet moves and is removed. In particular, this vibration method can remove not only droplets larger than 20 μl, but also droplets smaller than 20 μl, and can actually remove droplets of several fl (femtoliter) size. The actual size of rainwater is less than 20µl.

On the other hand, when a high frequency (for example, 10 kHz or more) voltage is applied to the electrode, a phenomenon in which the droplets are significantly spread in the longitudinal direction occurs, and as a result, the droplets are hardly slid, and thus the droplet removal is not easy. Therefore, unless the substrate is inclined at a large angle, the droplet does not slide in the direction of gravity, and even if it can be removed, only droplets of 20 μl or more can slide. That is, when a high frequency voltage is applied, it is impossible to actually remove rainwater.

Hereinafter, the configuration of the cleaning device 100 will be described with reference to FIGS. 2 and 3.

2 and 3 are diagrams showing the configuration of a cleaning device according to an embodiment of the present invention.

The cleaning device 100 includes a substrate (Windshield Glass; for example, a vehicle glass or camera substrate, 110), an electrode 120, an insulating film 130, a hydrophobic layer 140 ) And a DC voltage application unit 150 may be included.

The substrate 110 is the lowest layer of the cleaning device 100.

Meanwhile, the electrode 120 is a transparent electrode and is continuously disposed on the upper surface of the substrate 110 to form a specific pattern.

Here, the electrode 120 may have a linear shape, a streamline shape, or a ring shape, and the shape of the pattern formed by the plurality of electrodes 120 is not limited.

Meanwhile, as shown in FIGS. 2 and 3, the insulating layer 130 may be stacked on the upper surface of the electrode 120, and may fill a gap between the electrodes 120.

For reference, the insulating layer 130 may include at least one material selected from the group consisting of feralin C, Teflon, and metal oxide layers.

Meanwhile, the hydrophobic layer 140 is an uppermost layer of the cleaning device 100, and droplets are formed on the surface thereof, and may be formed of a material having low affinity with a fluid such as water.

Accordingly, droplets can easily move on the surface of the hydrophobic layer 140.

Meanwhile, the DC voltage applying unit 150 may sequentially alternately apply a ground voltage and a high voltage, which are DC voltages, to each electrode 120 in a predetermined cycle.

At this time, the droplet moves from the surface of the hydrophobic layer 140 in the direction from the electrode to which the ground voltage is applied to the electrode to which the high voltage is applied, and eventually moves to the outermost side of the hydrophobic layer 140, thereby moving the substrate ( 110) can be cleaned.

As another embodiment of the cleaning device 100, as shown in FIG. 3, the cleaning device 100 includes a cover glass 110, an electrode 120, an insulating film 130, a hydrophobic film 140, and an AC voltage applied. It may include a unit 160.

That is, in the cleaning device 100 of another embodiment, the cover glass 110, the electrode 120, the insulating film 130, and the hydrophobic film 140 are all the same, and the DC voltage applying unit 150 is the AC voltage applying unit ( 160).

The AC voltage applying unit 160 may apply an AC voltage to the electrode 120, and droplets formed on the surface of the hydrophobic layer 140 are vibrated by applying the AC voltage to the electrode 120.

In this case, due to the inclination of the substrate 110, the droplet moves to the outside of the hydrophobic layer 140 along the inclination, so that the substrate 110 may be cleaned.

As another embodiment of the cleaning device 100, the cleaning device 100 includes a cover glass 110, an electrode 120, an insulating film 130, a hydrophobic film 140, a DC voltage application unit 150, and an AC voltage. It may include an application unit 160 and a voltage mode selection unit (not shown).

That is, in the cleaning device 100 of another embodiment, the cover glass 110, the electrode 120, the insulating film 130, the hydrophobic film 140, the DC voltage applying unit 150 and the AC voltage applying unit 160 are All are the same, and a voltage mode selector (not shown) is added.

The voltage mode selection unit (not shown) determines whether to remove the droplet by applying a DC voltage to the electrode 120 or removing the droplet by vibration by applying an AC voltage to the electrode 120 depending on the situation where the vehicle glass is installed. A voltage may be applied to the electrode 120 by using one of the DC voltage application unit 150 and the AC voltage application unit (not shown) according to the user's selection.

4 is a flowchart illustrating a cleaning process according to an embodiment of the present invention, and FIG. 5 is a flowchart illustrating a cleaning process according to another embodiment of the present invention.

In FIGS. 4 and 5, the cleaning device 100 is connected to a controller of a camera or an electronic system of a vehicle that can be operated by a driver, and hereinafter, the cleaning device 100 shown in FIGS. 2 and 3 The flow chart of FIGS. 4 and 5 will be described as a main subject.

The cleaning device 100 receives a droplet removal request signal through an electronic system operated by the driver (S410, S510).

After S410, the cleaning device 100 sequentially alternately applies DC voltages, ground and high, to each electrode 120 in a predetermined period according to the input droplet removal request signal (S420).

At this time, the droplets formed on the surface of the hydrophobic layer 140 alternately with ground and high are moved to the outside of the hydrophobic layer 140 by the DC voltage applied to each electrode 120, and the substrate ( 110) can be cleaned.

As another embodiment, as shown in FIG. 5, when an AC voltage is applied to the electrode 120 in step S520 after S510, droplets formed on the surface of the hydrophobic film 140 vibrate due to the application of the AC voltage. Then, the substrate 110 may be cleaned by moving to the outside of the hydrophobic layer 140 along the slope of the substrate 110.

After S420 or S520, when a predetermined time elapses or when a drop removal request signal is input from the driver, the cleaning device 100 stops applying the DC voltage or the AC voltage to each electrode (S430, S530).

6 is a diagram illustrating an actual cleaning process of a cleaning device according to another embodiment of the present invention. That is, FIG. 6 shows that the lens unit cleaning device 100 removes dust and frost generated on the substrate (vehicle glass 110).

Referring to FIG. 6, the cleaning device 100 according to an embodiment of the present invention may slide and remove droplets even on a surface to which dust is attached. At this time, since the droplet moves and adsorbs the surrounding dust, it is possible to remove the dust attached to the surface at the same time as the droplet is removed.

In addition, since the cleaning device 100 according to the embodiment of the present invention generates heat from the electrode 120 portion on the same principle as the heating wire of the insulator, it is possible to remove frost generated on the surface.

7 is an actual use scene of a cleaning device according to an embodiment of the present invention.

Each droplet having a size of 1 μl, 3 μl, and 5 μl is formed on the surface of the hydrophobic layer 140.

For reference, the plurality of electrodes 120 are transparent electrodes.

In the (a) state, when ground and high, which are DC voltages, are sequentially alternately applied to each electrode 120 at a predetermined period, or when AC voltage is applied, each droplet moves downward as shown in (b) and (c). , Can be finally cleaned as shown in (d). Of course, as shown in FIG. 7, fine particles may remain.

8 is a diagram illustrating a droplet removal process of a cleaning device according to an embodiment of the present invention, and FIG. 9 is a diagram showing a schematic structure of a cleaning device according to an embodiment of the present invention. 10 is a diagram illustrating an electrode pattern according to an embodiment of the present invention, and FIG. 11 is a diagram illustrating a flow of droplets when a droplet is removed according to an embodiment of the present invention. 12 is a diagram illustrating a change in a droplet contact angle when a droplet is removed according to an embodiment of the present invention, and FIG. 13 is a diagram showing a result of a droplet removal experiment.

Fig. 8(A) shows the change of the surface of the camera as the cleaning device of the present invention, and Fig. 8(B) shows the movement of droplets in the glass structure of the present invention.

As shown in (A) of FIG. 8, when a specific voltage is applied to the electrode when droplets are attached to the surface of the camera, as shown in the image on the right, droplets in the cleaning area of the camera surface are removed, and as a result, cleaning The area becomes clear. Here, the cleaning area is an area required for photographing and may correspond to a lens unit.

As shown in FIG. 8(B), when a specific voltage is applied to the electrode when droplets are attached to the surface of the glass structure, droplets such as rainwater move in the direction of gravity along the slope of the glass structure. As a result, droplets are removed.

In particular, since the glass structure of the present invention uses the electrowetting technology, the response speed is fast due to the nature of the electrowetting technology, so that the droplet can be quickly removed.

A cleaning device for removing such droplets, in particular, a portion of the cleaning device corresponding to the cleaning area may have the structure of FIG. 9.

Referring to FIG. 9, the cleaning device of the present embodiment may include a base layer (substrate 900), an electrode 902, an insulating layer 904, and a hydrophobic layer 906.

The base layer 900 may be a cover glass that protects the cleaning device from external contamination and impact, and may be arranged on, for example, a lens unit (not shown).

According to one embodiment, the base layer 900 may be non-wet glass.

The electrode 902 may be, for example, a transparent electrode made of ITO or the like, and may be formed on the base layer 900 in a predetermined pattern.

According to an embodiment, the electrode 902 may include a first electrode 1000 having a comb structure and a second electrode 1002 having a comb structure as illustrated in FIG. 10.

The first electrode 1000 may include a first base pattern 1010 and at least one first branch pattern 1012.

A portion of the first base pattern 1010 is electrically connected to the power source 908 or the ground, and a specific voltage is applied to the first base pattern 1010 from the power source or the ground. Meanwhile, the power source 908 may be located inside or outside the cleaning device.

The first branch pattern 1012 is formed to extend in length from the first base pattern 1010 in a direction intersecting with the first base pattern 1010, preferably in a vertical direction. As a result, when a specific voltage is applied to the first base pattern 1010, the specific voltage is also supplied to the first branch pattern 1012.

According to an embodiment, the first branch patterns 1012 may extend from the first base pattern 1010, and intervals between the first branch patterns 1012 may be the same. Of course, some of the intervals between the first branch patterns 1012 may be different as long as the first branch patterns 1012 and the second branch patterns 1020 intersect.

The second electrode 1002 may include a second base pattern 1022 and at least one second branch pattern 1020.

A portion of the second base pattern 1022 is electrically connected to the power source 908 or the ground, and a specific voltage is applied to the second base pattern 1022 from the power source 908 or the ground.

The second branch pattern 1020 is formed to extend in length from the second base pattern 1022 in a direction intersecting with the second base pattern 1022, preferably in a vertical direction. As a result, when a specific voltage is applied to the second base pattern 1022, the specific voltage is also supplied to the second branch pattern 1020.

Further, the second branch patterns 1020 are arranged to cross the first branch patterns 1012 as shown in FIG. 10. However, the first branch patterns 1012 and the second branch patterns 1020 may be physically separated.

According to an embodiment, the second branch patterns 1020 may extend from the second base pattern 1022, and intervals between the second branch patterns 1020 may be the same. Of course, as long as the first branch patterns 1012 and the second branch patterns 1020 intersect, some of the intervals between the second branch patterns 1020 may be different.

Meanwhile, in order to generate vibration on the surface of the cleaning device, a first voltage may be applied to one of the first electrode 1000 and the second electrode 1002 and a second voltage lower than the first voltage may be applied to the other. . Here, the first voltage may be a positive voltage and the second voltage may be a ground voltage.

Referring again to FIG. 9, the insulating layer 904 is arranged on the electrode 902, and may fill a gap between the electrodes 1000 and 1002.

According to an embodiment, the insulating layer 904 may include at least one material selected from the group consisting of feralin C, Teflon, and metal oxide layers.

The hydrophobic layer 906 is formed on the insulating layer 904 and may be made of a material having low affinity with a fluid such as water. As a result, droplets can easily move on the surface of the hydrophobic film 906.

A cleaning operation in a cleaning device having such a structure will be described.

For example, when a user inputs a droplet removal command, the power source 908 applies a first voltage to one of the electrodes 100 and 1002 according to the control of the controller, and a second voltage lower than the first voltage to the other electrode. Apply voltage. As a result, droplets attached to the surface of the cleaning device are vibrated.

As the surface of the cleaning device vibrates, the adhesion between the surface and the droplet decreases. In this case, since the surface of the cleaning device is inclined in the direction of gravity, droplets attached to the surface are slipped in the direction of gravity as shown in FIG. 11 and are separated from the cleaning device. That is, the droplet is removed from the cleaning device.

In particular, since the cleaning device of this embodiment uses the electrowetting technique, the droplet removal time is fast and efficient.

According to an embodiment, when a droplet is vibrated, a movement direction of the droplet, a change in a contact angle in a direction opposite to the movement direction, and a change in a contact angle in another direction may be different. This difference can be useful for slipping the droplet. In addition, even though the inclination of the surface of the cleaning device is low due to the difference in the contact angle, the droplet may be removed by sliding in the direction of gravity.

According to another embodiment, the electrodes 1000 and 1002 may have a comb shape, and the grains of the branch patterns 1012 and 1020 may be formed in the direction of gravity. As a result, when the droplet vibrates due to a specific voltage, the change in the contact angle of the droplet increases in the grain direction of the branch patterns 1012 and 1020 as shown in FIG. 12.

That is, the direction in which the droplet slides and the grain direction of the electrodes 1000 and 1002 are identical or similar, and as a result, the droplet slides more easily when the droplet is vibrated. Therefore, even if a lower voltage is applied to the electrodes 1000 and 1002, the droplet can be easily removed.

Looking at another point of view, if a cleaning device is implemented in which a change in the contact angle of the droplet in the direction in which the droplet slides, that is, in the direction of gravity, is greater than that in the other direction, the droplet can be easily removed.

Hereinafter, we will look at the actual experimental results.

As a result of an actual experiment while driving after mounting a general camera and a camera to which the cleaning device of the present invention is applied on a vehicle on a rainy day, as shown in Fig. 13A, droplets on the surface of the camera to which the cleaning device is applied (rainwater) It can be seen that the video was taken much more clearly by removing this.

In addition, as a result of an actual experiment on a vehicle using a glass structure as a windshield on a rainy day, it can be seen that the droplets of the windshield are completely removed as shown in FIG. 13B, and the windshield becomes clear.

14 is a diagram schematically illustrating an electrode of a cleaning device according to another embodiment of the present invention. However, since the electrodes differ only in the arrangement direction and have the same structure, only one electrode is shown. Of course, the branches of the electrodes can be arranged to cross each other.

Referring to FIG. 14, one of the electrodes may include a base pattern 1400 and at least one branch pattern 1402.

The branch pattern 1402 may include a branch portion 1410 and at least one protrusion 1412 protruding from the branch portion 1410. That is, unlike the branch pattern of FIG. 10, the branch pattern 902 of the present exemplary embodiment may include at least one protrusion 912. When the protrusion 912 is formed, the entire surface area of the electrode may be increased.

Of course, branch patterns of the electrodes may be arranged to cross each other similarly to the branch patterns of FIG. 10.

In addition to the cleaning device of the above embodiments, the structure of the cleaning device may be variously modified as long as the cleaning device can remove droplets.

According to an embodiment, the cleaning device may include a vibrating unit that vibrates a droplet attached to a surface to reduce adhesion between the droplet and a surface of the cleaning device. The vibration unit has a specific pattern. In addition, the surface of the cleaning device is inclined in the direction of gravity, and the grain of the pattern is the same as the moving direction of the droplet, so that the droplet may move along the grain.

Of course, according to the vibration, a change in the contact angle of the droplet in the moving direction and in a direction opposite to the moving direction may be greater than that in the other direction.

According to another embodiment, the cleaning device may include a vibrating unit that vibrates a droplet attached to a surface of the cleaning device to reduce adhesion between the droplet and the surface of the cleaning device. Here, the surface of the cleaning device has a structure such that when the droplet moves according to the vibration, a change in the contact angle of the droplet in the moving direction or in a direction opposite to the moving direction is greater than a change in the contact angle of the droplet in other directions. I can.

Meanwhile, the vibration unit may include an electrode, and a grain of the electrode may be the same as a moving direction of the droplet.

According to another embodiment, the cleaning structure may include a base layer, a first electrode and a second electrode disposed on the base layer, and a droplet support layer disposed on the electrodes. Here, the droplet support layer may include an insulating layer and a hydrophobic layer. In addition, the first electrode and the second electrode are arranged to cross each other in a physically separated state.

According to yet another embodiment, the cleaning structure includes a base layer, an electrode arranged on the base layer, and a droplet support layer arranged on the electrode. Here, the electrode may have a pattern structure such that a change in a contact angle of the droplet in a moving direction is different from a change in a contact angle of the droplet in another direction when the droplet moves according to the vibration of the droplet on the droplet support layer.

According to yet another embodiment, the cleaning structure includes a base layer, an electrode arranged on the base layer, and a droplet support layer arranged on the electrode. Here, when the droplet moves on the droplet supporting layer, the moving direction and the grain direction of the electrode or the droplet supporting layer are the same.

15 is a diagram illustrating a droplet removal process of a cleaning device according to an embodiment of the present invention. 16 is a diagram illustrating an electrode pattern according to an embodiment of the present invention, and FIG. 17 is a diagram illustrating a flow of droplets when a droplet is removed according to an embodiment of the present invention. FIG. 18 is a view showing a change in a droplet contact angle when a droplet is removed according to an embodiment of the present invention, and FIG. 19 is a view showing a flow of a droplet when a droplet is removed according to another embodiment of the present invention. 20 and 21 are diagrams showing the droplet removal experiment results.

15 shows the surface change of the cleaning device of the present invention. As shown in FIG. 15, when a specific voltage is applied to the electrode when droplets are attached to the surface of the cleaning device, as shown in the image on the right, droplets on the surface are removed and the surface becomes clear.

The cleaning device for removing such droplets may have the structure of FIG. 9. However, the structure of the electrode 902 is different from the structure of FIG. 10.

According to an embodiment, the electrode 902 may include a first electrode 1600 and a second electrode 1602 as shown in FIG. 16.

The first electrode 1600 may include first sub-electrodes 1600a to 1600n, and the second electrode 1602 may also include second sub-electrodes 1602a to 1602n. Of course, it is preferable that the number of first sub-electrodes 1600a to 1600n and the number of second sub-electrodes 1602a to 1602n are the same, but may be different.

Each of the first sub-electrodes 1600a to 1600n may have a comb structure, and each of the second sub-electrodes 1602a to 1602n may have a comb structure.

The first sub-electrodes 1600a to 1600n are physically separated from each other, and the second sub-electrodes 1602a to 1602n are physically separated from each other. In addition, the first sub-electrodes 1600a to 1600n and the second sub-electrodes 1602a to 1602n are also physically separated.

Looking at the overall shape, each of the first electrode 1600 and the second electrode 1602 may have a comb shape.

Hereinafter, a structure of the sub-electrodes 1600a to 1600n and 1602a to 1602n will be described with the first sub-electrode 1600a and the second sub-electrode 1602a as representatives. Although not described, the other sub-electrodes 1600b to 1600n and 1602b to 1602n also have the same or similar structure as the sub-electrodes 1600a and 1602a.

The first sub-electrode 1600a may include a first base pattern 1610, a first input pattern 1612, and at least one first branch pattern 1614.

The first base pattern 1610 is connected to the first input pattern 1612 and serves to transfer a specific voltage input through the first input pattern 1612 to the first branch patterns 1614.

The first input pattern 1612 is electrically connected to the power source 908 or the ground. As a result, a specific voltage is input to the first input pattern 1612. Meanwhile, the power source 908 may be located inside or outside the cleaning device.

According to another embodiment, the first input pattern 1612 may not exist, and in this case, a specific voltage may be input as a part of the first base pattern 1610. Accordingly, a part of the first base pattern 1610 may have a structure electrically connected to the power source 908 or the ground.

The first branch pattern 1614 is formed to extend in length from the first base pattern 1610 in a direction intersecting with the first base pattern 1610, preferably in a vertical direction. As a result, when a specific voltage is applied to the first base pattern 1610, the specific voltage is also supplied to the first branch pattern 1614.

According to an embodiment, the first branch patterns 1614 may extend from the first base pattern 1610, and intervals between the first branch patterns 1614 may be the same. Of course, some of the intervals between the first branch patterns 1614 may be different as long as the first branch patterns 1614 and the second branch patterns 1624 intersect.

The second sub-electrode 1602a may include a second base pattern 1620, a second input pattern 1622, and at least one second branch pattern 1624.

The second base pattern 1620 is connected to the second input pattern 1622 and serves to transfer a specific voltage input through the second input pattern 1622 to the second branch patterns 1624.

The second input pattern 1622 is electrically connected to the power source 908 or ground. As a result, a specific voltage is input to the second input pattern 1622.

According to another embodiment, the second input pattern 1622 may not exist, and in this case, a specific voltage may be input as a part of the second base pattern 1620. Accordingly, a portion of the second base pattern 1620 may have a structure electrically connected to the power source 908 or the ground.

The second branch pattern 1624 is formed to extend in length from the second base pattern 1620 in a direction crossing the second base pattern 1620, preferably in a vertical direction. As a result, when a specific voltage is applied to the second base pattern 1620, the specific voltage is also supplied to the second branch pattern 1624.

Also, the second branch patterns 1624 are arranged to cross the first branch patterns 1614 as shown in FIG. 16. However, the first branch patterns 1614 and the second branch patterns 1624 may be physically separated.

According to an embodiment, the second branch patterns 1624 may extend from the second base pattern 1620, and intervals between the second branch patterns 1624 may be the same. Of course, as long as the first branch patterns 1614 and the second branch patterns 1624 intersect, some of the intervals between the second branch patterns 1624 may be different.

According to the intersection, the second branch pattern 1624 is physically separated and arranged between the first branch patterns 1614, and the first branch pattern 1614 is physically separated, It may be arranged between the branch patterns 1624.

Meanwhile, in order to remove droplets on the surface of the cleaning device, a first voltage is applied to one of the first sub-electrode 1600a and the second sub-electrode 1602a, and a second voltage lower than the first voltage is applied to the other. I can. Here, the first voltage may be a positive voltage and the second voltage may be a ground voltage.

Referring again to FIG. 9, the insulating layer 904 is arranged on the electrode 902 and may fill a gap between the electrodes 1600 and 1602.

A cleaning operation in a cleaning device having such a structure will be described.

First, let's look at the cleaning operation through the AC method.

For example, when a user inputs a droplet removal command, the power source 908 applies a first voltage to one of the electrodes 1600 and 1602 according to the control of the controller, and a second voltage lower than the first voltage to the other electrode. Apply voltage. As a result, droplets attached to the surface of the cleaning device are vibrated. Here, the first voltage may be simultaneously applied to all of the sub-electrodes 1600a to 1600n of the electrode 1600, and the second voltage may be simultaneously applied to all of the sub-electrodes 1602a to 1602n of the electrode 1602. have.

As the surface of the cleaning device vibrates, the adhesion between the surface and the droplet decreases. In this case, since the surface of the cleaning device is inclined in the direction of gravity, the droplets attached to the surface are slipped in the direction of gravity as shown in FIG. 17 and are separated from the cleaning device. That is, the droplet is removed from the cleaning device.

In particular, since the cleaning device of this embodiment uses the electrowetting technique, the droplet removal time is fast and efficient.

According to an embodiment, when the droplet is vibrated, a change in a contact angle in a direction opposite to the direction in which the droplet moves and a reflection in the direction may be different from the change in the contact angle in the other direction. This difference can be useful for slipping the droplet. In addition, even though the inclination of the surface of the cleaning device is low due to the difference in the contact angle, the droplet may be removed by sliding in the direction of gravity.

According to another embodiment, the electrodes 1600 and 1602 may have a comb shape, and the grains of the branch patterns 1612 and 1620 may be formed in the direction of gravity. As a result, when the droplet vibrates due to a specific voltage, the change in the contact angle of the droplet increases in the grain direction of the branch patterns 1612 and 1620 as shown in FIG. 5.

That is, the direction in which the droplet slides and the grain direction of the electrodes 1600 and 1602 are identical or similar, and as a result, the droplet slides more easily when the droplet is vibrated. Thus, even if a lower voltage is applied to the electrodes 1600 and 1602, the droplet can be easily removed.

Looking from another viewpoint, if a cleaning device is implemented in which the change in the contact angle of the droplet in the direction in which the droplet slides, that is, in the direction of gravity, is larger than the change in the contact angle in other directions, the droplet can be easily removed.

Next, we will look at the cleaning operation through the DC method.

The direct current method is a method of sequentially applying a specific voltage to the sub-electrodes 1600a to 1600n and 1602a to 1602n.

For example, a first voltage, which is a positive voltage, may be applied to the sub-electrode 1600a, and a second voltage lower than the first voltage may be applied to the sub-electrode 1602a corresponding to the sub-electrode 1600a. Here, the second voltage may be a ground voltage, and the other sub-electrodes 1600b to 1600n and 1602b to 1602n are in an inactive state. As a result, the droplets arranged on the sub-electrodes 1600a and 1602a move in the direction in which the voltage is applied.

Subsequently, a first voltage may be applied to the sub-electrode 1600b, and a second voltage may be applied to the sub-electrode 1602b corresponding to the sub-electrode 1600b. Here, the other sub-electrodes 1600a, 1600c to 1600n, 1602a, 1600c to 1602n are in an inactive state. As a result, the droplets moved from the sub-electrodes 1600a and 1602a and the droplets arranged on the sub-electrodes 1600b and 1602b move in the direction to which the first voltage is applied.

The above sequential voltage application process is performed until voltages are applied to the last sub-electrodes 1600n and 1602n, and this sequential voltage application process is shown in FIG. 6.

Subsequently, a process of sequentially applying voltages to the sub-electrodes 1600a to 1600n and 1602a to 1602n is repeatedly performed. As a result, droplets adhering to the surface of the cleaning device can be easily removed.

Meanwhile, in the direct current method, a change in a contact angle of a droplet in a direction in which the droplet moves may be greater than a change in a contact angle in a direction opposite to the moving direction.

Hereinafter, we will look at the actual experimental results. FIG. 20A shows a process of removing droplets and hydrophilic dust, and FIG. 20B shows a process of removing droplets and hydrophobic dust.

As a result of an actual experiment while driving after installing the cleaning device of the present invention on a vehicle on a rainy day, droplets (rainwater) on the surface of the cleaning device are removed as shown in Fig. 20(a), so that the image becomes much clearer. It can be confirmed that it was filmed. In particular, as shown in (a) of FIG. 20, it can be seen that not only droplets but also dust are simultaneously removed.

In addition, as a result of an actual experiment on a vehicle using a glass structure as a windshield on a rainy day, it can be seen that the droplets of the windshield are completely removed as shown in (b) of FIG. 20 so that the windshield becomes clear. In particular, not only droplets but also dust can be removed at the same time.

In addition, as shown in Fig. 21, it was confirmed that the frost generated on the surface of the cleaning device was also removed.

In addition to the cleaning device of the above embodiments, the structure of the cleaning device may be variously modified as long as the cleaning device is capable of removing droplets, dust, or frost.

According to an embodiment, the cleaning device may include a vibrating unit that vibrates a droplet attached to a surface to reduce adhesion between the droplet and a surface of the cleaning device. The vibration unit has a specific pattern. In addition, the surface of the cleaning device is inclined in the direction of gravity, and the grain of the pattern is the same as the moving direction of the droplet, so that the droplet may move along the grain.

22 is a diagram schematically illustrating a configuration of a camera droplet detection device according to an embodiment of the present invention, FIG. 23 is a diagram illustrating an impedance change of a camera cover glass according to the presence or absence of droplets, and FIG. 24 is a camera cover It is a diagram showing an example of an image photographed when droplets are generated on the glass. Hereinafter, a configuration of a camera droplet detection apparatus according to an embodiment of the present invention will be described with reference to FIG. 22, but reference will be made to FIGS. 23 and 24.

First, referring to FIG. 22, a camera droplet detection apparatus according to an embodiment of the present invention includes a camera unit 10, an impedance measurement unit 20, a control unit 30, and a voltage application unit 40.

The camera unit 10 includes a camera module 11 and a camera cover glass 15 covering the lens of the camera module 11.

The camera module 11 creates an image by photographing a subject through a lens. For example, the camera module 11 is composed of elements of a transparent material such as glass made of a spherical or aspherical surface, and a lens module that generates an optical image by converging or diverging light, and the generated optical image It may be configured to include an image sensor that converts into a signal, a PCB including various circuits that process electrical signals generated by the image sensor, and the like.

The camera cover glass 15 includes a cover glass layer 16, a transparent electrode 17 and a hydrophobic and dielectric layer 18.

The cover glass layer 16 is the lowermost layer of the camera cover glass 15 and serves to directly cover the lens of the camera module 11 and serves as a substrate for the camera cover glass 15.

The transparent electrode 17 is continuously disposed on the upper surface of the cover glass layer 16 to form a preset pattern. For example, the transparent electrode 17 may have a linear shape, a streamline shape, or a ring shape. The shape of the pattern formed by the plurality of transparent electrodes 17 is not limited.

The hydrophobic insulating film 18 is an uppermost layer of the camera cover glass 15, and is laminated on the upper surface of the plurality of transparent electrodes 17 as shown in FIG. 22 to fill between the transparent electrodes 17.

For example, the hydrophobic insulating layer 18 may include at least one material selected from the group consisting of feralin C, Teflon, and metal oxide layers.

In addition, droplets are formed on the surface of the hydrophobic insulating layer 18.

For example, the hydrophobic insulating layer 18 may be made of a material having low affinity with a fluid such as water, and thus, droplets can easily move on the surface of the hydrophobic insulating layer 18.

The impedance measuring unit 20 measures the impedance of the transparent electrode 17. To this end, a fine voltage may be constantly applied to the transparent electrode 17 by the voltage application unit 40. For example, a ground voltage and a high voltage, which are DC voltages, may be finely applied to each of the two transparent electrodes 17.

The control unit 30 determines whether or not droplets are generated on the camera cover glass 15 by using the impedance of the transparent electrode 17 measured by the impedance measuring unit 20 or the image captured by the camera module 11.

That is, the control unit 40 may check the impedance of the transparent electrode 17 measured by the impedance measuring unit 20, and when the impedance changes, it may be determined that a droplet has occurred in the camera cover glass 15.

For example, referring to FIG. 23, as shown on the left side of FIG. 23, the transparent electrode 17 and the hydrophobic insulating film 18 of the camera cover glass 15 are respectively a resistance component and a capacitor. Can have ingredients. In addition, as shown on the right side of FIG. 23, droplets generated on the surface of the hydrophobic insulating layer 18 of the camera cover glass 15 may themselves have a resistance component and a capacitor component. Therefore, when a droplet is generated on the surface of the hydrophobic insulating film 18 of the camera cover glass 15, the impedance of the transparent electrode 17 at the location where the droplet is generated is changed.

In addition, the controller 40 analyzes the image captured by the camera module 11, and as a result of the analysis, when the image is distorted in a certain circular shape, it may be determined that a droplet has occurred in the camera cover glass 15. . For example, as shown in FIG. 24, when a large number of droplets are generated on the camera cover glass 15, the captured image may be distorted in a certain circular shape.

Here, in order to determine that the image is distorted in a certain circular shape, the controller 40 may check whether there is a circular droplet shape in the image or calculate the sharpness of the image.

That is, the controller 40 may determine that the image is distorted in a certain circular shape when a number of circular droplet shapes are found in the image or when the sharpness of the image is less than a preset reference sharpness.

In addition, the control unit 30 controls the voltage application unit 40 to apply a voltage to the transparent electrode 17 when droplets are generated on the camera cover glass 15.

The voltage applying unit 40 applies a voltage to the transparent electrode 17 in order to remove droplets generated on the camera cover glass 15 under the control of the controller 30.

That is, the voltage applying unit 40 may sequentially alternately apply a ground voltage and a high voltage, which is a DC voltage, to each transparent electrode 17 at a predetermined period.

For example, the droplet moves from the surface of the hydrophobic insulating film 18 in the direction of the electrode to which the ground voltage is applied and the electrode to which the high voltage is applied, and eventually moves to the outermost side of the hydrophobic insulating film 18, The camera cover glass 15 can be cleaned.

Alternatively, the voltage applying unit 40 may apply an AC voltage to the transparent electrode 17.

For example, when an AC voltage is applied to the transparent electrode 17, droplets formed on the surface of the hydrophobic insulating layer 18 vibrate due to the AC voltage applied to the transparent electrode 17. In addition, the droplet moves to the outermost side of the hydrophobic insulating film 18 along the slope due to vibration and the inclination of the camera cover glass 15, so that the camera cover glass 15 can be cleaned.

25 is a flowchart illustrating a camera droplet detection method according to an embodiment of the present invention.

In step S2500, the camera droplet detection device measures the impedance of each transparent electrode 17 of the camera cover glass 15.

In step S2502, the camera droplet detection device checks whether the measured impedance of the transparent electrode 17 changes.

In step S2504, when the impedance of the transparent electrode 17 changes, the camera droplet detection device determines that the droplet has been detected.

In step S2506, the camera droplet detection device removes the droplet by applying a voltage to the transparent electrode 17 as the droplet is detected.

26 is a flowchart illustrating a camera droplet detection method according to another embodiment of the present invention.

In step S2600, the camera droplet detection device captures an image through the camera module 11.

In step S2602, the camera droplet detection device analyzes the captured image.

In step S2604, the camera droplet detection apparatus determines that the droplet has been detected when the image is distorted in a certain circular shape as a result of analyzing the captured image.

Here, the camera droplet detection device checks for the existence of a circular droplet shape in the image, calculates the sharpness of the image, and then finds a large number of circular droplet shapes in the image, or when the sharpness of the image is less than a preset reference sharpness, It can be determined that the image is distorted in a certain circular shape.

In step S2606, the camera droplet detection device removes the droplet by applying a voltage to the transparent electrode 17 as the droplet is detected.

27 is a diagram illustrating a cleaning device according to an embodiment of the present invention, and FIG. 28 is a diagram illustrating an electrode pattern of the cleaning device according to an embodiment of the present invention.

The cleaning device according to the embodiment of the present invention may be applied to a cover glass of a camera lens as shown in FIG. 27. Of course, the cleaning device according to an embodiment of the present invention can be applied to not only a cover glass of a camera lens, but also an object requiring removal of droplets formed on the surface, such as a windshield of a vehicle. Hereinafter, the understanding and explanation of the invention For convenience, it is assumed that the cleaning device 100 according to an embodiment of the present invention is applied to a cover glass of a camera lens.

The cleaning device 100 may be formed by patterning a plurality of electrodes separated from each other on a microchip manufactured by a MEMS process, and applying a DC voltage or an AC voltage to the plurality of electrodes to remove droplets formed on the surface. can do.

For example, the cleaning device may change the surface tension of a droplet by applying a voltage to each electrode in a different DC voltage condition (high, ground). In this case, the droplet moves in the direction of the electrode to which the high voltage and the ground voltage are applied (eventually, the outer side of the cover glass of the camera lens).

In addition, the cleaning device may change the surface tension of the droplet by vibrating the droplet by applying a low-frequency alternating voltage to the electrode. As shown in FIG. 27, if the camera lens has a predetermined inclination with respect to the plane, the droplets vibrate and move downward (eventually, the outer side of the cover glass of the camera lens).

In particular, the cleaning device 100 according to an embodiment of the present invention applies a low-frequency AC voltage along with a high-frequency AC voltage to a plurality of electrodes based on a preset frequency in order to remove not only conductive droplets but also non-conductive droplets. That is, the cleaning device applies a high-frequency AC voltage to a plurality of electrodes, and switches the applied high-frequency AC voltage to a low frequency with respect to the high-frequency AC voltage, so that the high-frequency AC voltage and the low-frequency AC voltage are Simultaneously apply to remove both the non-conductive and conductive droplets.

Here, the reference frequency for distinguishing the high frequency and the low frequency may be 1 kHz, the high frequency may mean more than the reference frequency, and the low frequency may mean less than the reference frequency.

For example, the high frequency may be 10 kHz, the low frequency may be 31 Hz, and as a result of testing under these conditions, it was confirmed that both non-conductive and conductive droplets were removed.

For reference, when only the low-frequency voltage is applied to the plurality of electrodes, the surface tension of the conductive droplets is periodically changed to vibrate at a low frequency, and the non-conductive droplets do not change.

In addition, when a high-frequency voltage is applied to a plurality of electrodes, both the conductive droplet and the non-conductive droplet are spread and flattened.

On the other hand, when the high frequency alternating voltage applied to the plurality of electrodes is switched on/off at a low frequency, the phenomenon of spreading and flattening both conductive and non-conductive droplets on the surface is repeated and vibrated periodically. By moving by, it can be removed.

The plurality of electrodes according to the embodiment of the present invention is divided into a plurality of high voltage electrodes and a plurality of ground voltage electrodes, and a high voltage electrode and a ground voltage electrode cover the camera lens. They are arranged in series, alternately, separated from each other on the glass surface. In this case, a plurality of high voltage electrodes and a plurality of ground voltage electrodes are formed integrally, so that high voltage electrodes and ground voltage electrodes may be connected to each other.

For example, referring to FIG. 28, a high voltage electrode and a ground voltage electrode have a comb shape, respectively, and may be arranged in a shape that does not touch each other but meshes.

29 is a view schematically illustrating a configuration of a cleaning device according to an embodiment of the present invention, and FIGS. 30 to 33 are diagrams for explaining a cleaning device according to an embodiment of the present invention. Hereinafter, a cleaning device according to an embodiment of the present invention will be described with reference to FIG. 29, but reference will be made to FIGS. 30 to 33.

A cleaning device according to an embodiment of the present invention includes a substrate 2900, an electrode 2902, an insulating layer 2904, a hydrophobic layer 2906, and a voltage application unit ( 2908) and a switching unit 2910.

The substrate 2900 is the lowest layer of the cleaning device and is a base.

Meanwhile, the electrode 2902 is a transparent electrode and may be continuously disposed on the upper surface of the substrate 2900 to form a specific pattern.

That is, as described above with reference to FIG. 28, the electrodes 2902 are continuously disposed so that a plurality of integrally formed high voltage electrodes and a plurality of integrally formed ground voltage electrodes alternate with each other.

Meanwhile, as shown in FIG. 29, the insulating layer 2904 is stacked on the upper surface of the electrode 2902, and may fill the gap between the electrodes 2902.

The hydrophobic layer 2906 is an uppermost layer of a cleaning device, and droplets are formed on a surface thereof, and may be formed of a material having low affinity with a fluid such as water. Accordingly, droplets can easily move on the surface of the hydrophobic film 2906.

The voltage applying unit 2908 applies a high-frequency AC voltage to the electrode 2902 based on a preset reference frequency.

The switching unit 2910 switches on/off the high-frequency AC voltage at a low frequency with respect to the high-frequency AC voltage. For example, the switching unit 2910 may control the voltage applying unit 2908 to generate a high-frequency AC voltage at a cycle corresponding to a low frequency. Alternatively, the switching unit 2910 may switch on/off the high-frequency AC voltage output from the voltage applying unit 2908 between the voltage applying unit 2908 and the electrode 2902.

In this way, by switching the high-frequency AC voltage on/off by the switching unit 2910, a low-frequency AC voltage may be generated, and the conductive droplets and non-conductive droplets formed on the surface of the hydrophobic film 2906 are high-frequency alternating current. The voltage and the low-frequency AC voltage are simultaneously applied to the electrode 120, thereby causing vibration.

At this time, if the substrate 2900 has a predetermined inclination with respect to the plane, the droplet moves to the outside of the hydrophobic layer 2906 along the inclination due to the inclination of the substrate 110, so that the substrate 2900 can be cleaned. have.

In another embodiment, the cleaning device according to the embodiment of the present invention includes a frequency generator (not shown) that simultaneously generates a high-frequency voltage and a low-frequency voltage in place of the voltage applying unit 2908 and the switching unit 2910. can do.

The frequency generator applies a specific voltage to the electrode 2900 and controls the high frequency voltage and the low frequency voltage to be generated within one period based on the reference frequency. As a result, as the high-frequency voltage and the low-frequency voltage are applied to the electrode 2902, both conductive droplets and non-conductive droplets are removed, so that the substrate 2900 can be cleaned.

For example, referring to FIG. 30, when a high frequency AC voltage applied to the electrode 2902 is switched on and off at a relatively low frequency, the contact angle between the droplet and the surface of the hydrophobic film 2906 This repetitively changes, so that both the non-conductive droplet and the conductive droplet vibrate regularly.

That is, when a low-frequency AC voltage is applied to the electrode 2902, the conductive droplet vibrates according to the electrowetting principle, and the non-conductive droplet vibrates according to the dielectrophoresis principle when a high-frequency AC voltage is applied to the electrode 120. do. Here, the dielectrophoretic principle is a phenomenon in which when a non-polar particle is exposed to an uneven alternating current electric field, a dipole is induced to the particle and a force is received in a direction with a large or small gradient of the electric field.

For example, referring to FIG. 31, as shown in FIG. 31(a), the surface tension of the conductive droplet is changed according to the principle of electrowetting, so that the contact angle between the droplet and the surface of the hydrophobic layer 2906 may be changed. . In addition, as shown in FIG. 31B, the surface tension of the non-conductive droplet is changed according to the principle of dielectrophoresis, so that the contact angle between the droplet and the surface of the hydrophobic layer 2906 may be changed.

As described above, when droplets generated on the surface of the hydrophobic layer 2906 vibrate, adhesion between the droplet and the surface of the hydrophobic layer 2906 decreases. Therefore, when the surface of the hydrophobic film 2906 is inclined, when the cleaning device according to the embodiment of the present invention is driven, as shown in FIG. 32, droplets generated on the surface of the hydrophobic film 2906 are moved downward by gravity. You can slide and move. (A) of FIG. 32 shows that the conductive droplet vibrates and slides, and (b) shows that the non-conductive droplet vibrates and slides.

In addition, when the surface of the hydrophobic film 2906 is inclined, when a droplet generated on the surface of the hydrophobic film 2906 vibrates, a difference occurs between the contact angle of the portion in the moving direction of the droplet and the contact angle of the portion in the opposite direction to the moving direction. This difference helps the droplet to slide down and can cause the droplet to slide even on the surface of the hydrophobic film 2906 with a very small slope.

Further, since the electrode 2902 is formed in a comb shape as described above in FIG. 28, the contact angle between the droplet and the surface of the hydrophobic layer 2906 is not uniform in all directions of the droplet, and as shown in FIG. 33, the electrode ( 2902). In addition, the difference in the contact angle between the moving direction and the opposite direction that occurs when the droplet vibrates on the inclined surface also occurs in the grain direction. As a result, as described above, since the difference in the contact angle between the moving direction and the opposite direction of the droplet helps the droplet to slide, matching the direction in which the droplet slides with the grain direction of the electrode 2902 makes the droplet at a lower voltage. You can slide quickly.

As described above, in the cleaning apparatus according to an embodiment of the present invention, in controlling droplets, not only the grain direction of the electrode but also the frequency of on/off switching is affected. Therefore, since each droplet has a specific natural frequency according to the size, when a voltage having a frequency corresponding to a specific natural frequency according to the size of the generated droplet is applied, the droplet vibrates more greatly, and thus the droplet becomes a hydrophobic film ( 2906) Can slide better on surfaces.

34 is a flow chart showing a cleaning method according to an embodiment of the present invention.

In FIG. 34, the cleaning device according to the embodiment of the present invention may be in a state of being coupled to a camera module (not shown) of a vehicle (for example, AVMS: Around View Monitoring System), and hereinafter, the cleaning device shown in FIG. 29 The flowchart of FIG. 34 will be described with the device as the main body.

In step S3400, the cleaning device receives a droplet removal request signal from a camera module of a vehicle to which a driver's request is input.

In step S3410, the cleaning device applies a high-frequency AC voltage to the electrode 120 based on a preset frequency according to the received droplet removal request signal.

In step S3420, the cleaning device turns on/off the high frequency AC voltage at a low frequency with respect to the applied high frequency AC voltage. At this time, by switching the high frequency AC voltage on/off, a low frequency AC voltage may be generated, and the conductive droplets and non-conductive droplets formed on the surface of the hydrophobic film 2906 have a high frequency AC voltage and a low frequency AC voltage. By simultaneously being applied to 2902, it vibrates.

In addition, the non-conductive droplet and the conductive droplet slide down along the slope of the glass 2900 to move to the outside of the hydrophobic layer 2906, so that the glass 2900 may be cleaned.

In step S3430, the cleaning device stops the application of the high frequency AC voltage and on/off switching of the high frequency AC voltage when a predetermined time elapses or when a droplet removal release request signal is input from the driver.

Hereinafter, the hydrophobic film of the cleaning device of the present invention will be described in detail with reference to the accompanying drawings.

The hydrophobic film used for electrowetting is generally made of a fluorine-based material. However, such a hydrophobic film is excellent in hydrophobic properties, but has poor durability, and thus, once installed, may not be suitable for cleaning devices used in automobiles, cameras, and the like that must be used for a long period of time. The present invention proposes a hydrophobic film having excellent durability as well as hydrophobic characteristics.

35 is a diagram schematically showing the structure of a cleaning device according to an embodiment of the present invention, and FIG. 36 is a diagram schematically showing a process of manufacturing a hydrophobic film according to an embodiment of the present invention.

Referring to FIG. 35, the cleaning device according to the present embodiment includes a substrate 3500, an electrode 3502 having a predetermined pattern, an insulating film 3504, and a hydrophobic film 3506.

Components other than the hydrophobic layer 3506 have been described above, and thus description thereof will be omitted.

The hydrophobic layer 3506 may have excellent hydrophobic properties and strong durability.

According to an embodiment, the hydrophobic film 3506 is a silane-based material (including a fluorine-based material containing a fluorine atom) and an organic material and an inorganic material that help bond to a fluorine-based material having water repellency, oil repellency, and chemical resistance. It may contain organic-inorganic silane compounds).

The hydrophobic film 3506 may have water repellency, oil repellency, and chemical resistance, as well as strong durability compared to a hydrophobic film made of a fluorine-based material.

Since the hydrophobic layer 3506 has strong durability, the hydrophobic layer 3506 may have sufficient durability even if it has a thin thickness (for example, several tens of nm). When the hydrophobic film 3506 is made of a thin thickness, the hydrophobic film 3506 may also have excellent light transmittance, and thus, a vehicle glass or a camera lens can secure a sufficient field of view while easily removing droplets.

According to an embodiment, the fluorine compound may contain 49 at% or more of fluorine atoms on its surface so that its surface is hydrophobic. The fluorine compound may be a polymer having a formula of -CxFy-, CxFyHz-, -CxFyCzHp-, -CxFyO-, -CxFyN(H)-, etc. (where x, y, z, p are each natural number), and amorphous It may be a fluorine compound, for example, a material such as AF1600. Here, the surface of the hydrophobic layer 3506 may mean a thin film ranging from a distance of 50 angstroms to a distance of 100 angstroms from the upper surface of the hydrophobic layer 3506 in the lower direction.

According to an embodiment, the organic-inorganic silane compound may be an organic-inorganic silane compound having one or more amino groups, vinyl groups, epoxy groups, alkoxy groups, halogen groups, mercapto groups, sulfide groups, and the like. Specifically, the functional organic-inorganic silane compound is aminopropyltriethoxysilane, aminopropyltrimethoxysilane, amino-methoxysilane, phenylaminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyl Trimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltridimethoxysilane, γ-aminopropyldimethoxysilane, γ-aminopropyltriethoxysilane, γ -Aminopropyldiethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(methoxyethoxy)silane, di-, tri- or tetraalkoxysilane, vinylmethoxysilane, vinyltrimethoxysilane, Vinylepoxysilane, vinyltriepoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrime Toxoxysilane, chlorotrimethylsilane, trichloroethylsilane, trichloromethylsilane, trichlorophenylsilane, trichlorovinylsilane, mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, bis(trimethoxysilyl) Propyl)amine, bis(3-triethoxysilylpropyl)tetrasulfide, bis(triethoxysilylpropyl)disulfide, (methacryloxy)propyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl From trimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and combinations thereof It may be selected, and preferably, it may be aminopropyltriethoxysilane or a combination comprising the same.

Looking at the experimental results, the contact angle between the hydrophobic film 3504 containing the fluorine-based material and the silane-based material and the droplet (water) was measured at a minimum of 115 degrees and a CAH of at most 7 degrees. That is, droplets can be well removed.

In addition, the hydrophobic film 3504 maintains a contact angle of 113 degrees even if the eraser rubs with a load of 500 g for 1500 times using the eraser wear resistance test equipment, and the duration is at least 1 year, the previously used fluorine-based hydrophobic film (e.g. For example, it was confirmed that it has very excellent durability compared to Teflon and Cytop).

Hereinafter, a process of manufacturing such a hydrophobic film 3504 will be described.

Referring to FIG. 36, the hydrophobic film 3504 may be manufactured in the vacuum chamber 3600.

A heating device 3610 and an object 3612 are located in the vacuum chamber 3600. Of course, the object 3612 may be fixedly supported in the vacuum chamber 3600. That is, although not shown, a support member for supporting the object 3612 may be formed in the vacuum chamber 3600.

The heating device 3610 serves to convert a hydrophobic material into steam by applying heat. The vapor generated by the heating device is deposited onto the object 3612, and as a result, a hydrophobic film 3504 is formed on the object 3612.

According to an embodiment, the heating device 3610 may generate steam by heating a solid hydrophobic material with E-beam or electric resistance heat. Here, the hydrophobic material may be a compound of a fluorine-based material and a silane-based material.

The object 3612 may be a structure on which the hydrophobic layer 3504 is to be deposited, that is, an electrode 3502 and an insulating layer 3504 sequentially formed on a substrate 3500.

Vapor generated by the heating device 3610 is deposited on the object 3612, and as a result, a hydrophobic film 3504 may be formed on the insulating film 3504.

37 is a cross-sectional view showing a sticker-type cleaning device according to another embodiment of the present invention, and FIGS. 38 and 39 are views illustrating a process in which a droplet is removed.

Referring to FIG. 37, the cleaning device according to the present embodiment may include a bonding layer 3700, a substrate 3702, electrodes 3704, and an insulating layer 3706. Also, a hydrophobic layer may be further formed on the insulating layer 3706. Other components except for the adhesive layer 3700 are the same as those of the above embodiments, and thus description thereof will be omitted.

That is, unlike other embodiments, the adhesive layer 3700 may be formed on the lowermost layer of the cleaning device of the present embodiment. Accordingly, the cleaning device can be attached to the surface of various devices. For example, the cleaning device may be attached to a camera, an image sensor, a vehicle glass and side mirror, an image monitor, a semiconductor device, etc. using the adhesive layer 3700. As a result, the device to which the cleaning device is attached can remove droplets.

In particular, when the cleaning device is implemented with a flexible material (for example, the substrate is made of a flexible material) as shown in FIG. 37, the cleaning device may have a curved structure, and therefore, even in an existing structure having a curved structure The cleaning device can be adaptively attached.

Such a sticker-type cleaning device can realize a droplet removal function by attaching it to existing devices that do not have a droplet removal function. If a cleaning device with a droplet removal function is attempted to be replaced with a device installed from the beginning, the cost is high, but if a sticker-type cleaning device is attached to a device without a droplet removal function, droplets can be removed while significantly saving costs.

Although a method of driving the cleaning device is not mentioned, all driving methods (direct current application method, AC application method, alternate application method of low-frequency voltage and high-frequency voltage, etc.) of the above embodiments can be applied.

For example, when an AC voltage is applied to the electrodes 3704 to vibrate the droplet 3710, the droplet 3710 is moved and removed as shown in FIG. 38, and in particular, AC power is turned on and off to the electrode. When applied to the field 3704, the conductive/non-conductive droplet 3710 may move and be removed. In addition, if many droplets exist on the surface of the cleaning device, as shown in FIG. 39, the droplets merge together to form droplets of different sizes, and the droplets may move and be removed. Here, the size of the combined droplets may be different.

Meanwhile, the constituent elements of the above-described embodiment can be easily grasped from a process point of view. That is, each component can be identified as a respective process. In addition, the process of the above-described embodiment can be easily grasped from the viewpoint of the components of the device.

The above-described embodiments of the present invention have been disclosed for the purpose of illustration, and those skilled in the art who have ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes and additions It should be seen as belonging to the following claims.

100: vehicle glass cleaning device
110: vehicle glass
120: electrode
130: insulating film
140: hydrophobic film
150: DC voltage application unit
160: AC voltage application unit

Claims (8)

In the sticker type cleaning device,
Board;
At least one electrode arranged on the substrate;
An insulating film arranged on the electrode;
A hydrophobic layer formed on the insulating layer; And
Including an adhesive layer arranged on the side opposite to the side surface of the substrate on which the electrodes are arranged,
The cleaning device can be attached to other devices through the adhesive layer, and when a specific voltage is applied to the electrode, droplets formed on the surface of the cleaning device are moved and removed, and the hydrophobic layer contains a fluorine-based material and an organic-inorganic silane compound,
The fluorine-based material is configured to contain 51 wt% or more of fluorine atoms on the surface so that the surface of the hydrophobic layer is hydrophobic,
A sticker type, characterized in that it is formed through a process of depositing steam obtained by heating a hydrophobic material containing the fluorine-based material and the organic-inorganic silane compound on the insulating layer so that the contact angle between the hydrophobic layer and the droplets is maintained at least 115 degrees. Cleaning device.
The method of claim 1,
Further comprising a voltage applying unit for applying an AC voltage to the electrodes,
As the AC voltage is applied to the electrodes, the droplet continuously vibrates, and according to the vibration, the droplet moves in a specific direction and is removed. The method of claim 1,
A voltage applying unit for applying a high-frequency AC voltage to the electrode based on a preset reference frequency; And
Further comprising a switching unit for switching on/off the applied high frequency AC voltage,
A low-frequency AC voltage is generated by switching the high-frequency AC voltage on and off, and the high-frequency AC voltage and the low-frequency AC voltage are both generated within one period, so that both conductive and non-conductive droplets can be removed. device. The sticker-type cleaning device according to claim 1, wherein the substrate is made of a flexible material and has a structure in which the cleaning device is bent. The method of claim 1, wherein the droplets are removed together with surrounding dust regardless of the pH or viscosity of the droplets, and the cleaning device includes a cover glass of an image sensor, a front, rear, left and right glass and side mirrors of a vehicle, an image monitor, or a semiconductor. Sticker type cleaning device, characterized in that it can be used by being attached to the device. The method of claim 1, wherein when a plurality of droplets are present on the surface of the cleaning device, when a specific voltage is applied to the electrode, the droplets are combined to form new droplets, and the new droplets are removed by moving in a specific direction. Sticker type cleaning device, characterized in that.

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