KR102070249B1 - Cleaning device for removing droplet using electrowetting and hydrophobic layer having strong durability in the same - Google Patents

Abstract

A cleaning apparatus including a hydrophobic film having a strong durability is disclosed. The cleaning device includes a substrate, at least one electrode arranged on the substrate, an insulating film arranged on the electrode, and a hydrophobic film arranged on the insulating film. Here, the hydrophobic film contains a fluorine-based material and a silane-based material.

Description

CLEANING DEVICE FOR REMOVING DROPLET USING ELECTROWETTING AND HYDROPHOBIC LAYER HAVING STRONG DURABILITY IN THE SAME}

The present invention relates to an apparatus and method for cleaning glass, such as a vehicle or a camera, and more particularly, to a technique for removing droplets formed on the surface of the glass.

The present invention also relates to a camera droplet sensing apparatus and method for sensing droplets.

In addition, the present invention relates to a cleaning apparatus and method for removing conductive and non-conductive droplets formed on a surface using the electrowetting-on-dielectric principle.

Moreover, the present invention relates to a cleaning device including a hydrophobic film having strong durability.

Recently, HUD (Head-up-display) technology that displays various driving information on the windshield according to the increase in the length of automobile parts and the spread of smart cars, and furthermore, the front glass of the vehicle as a transparent display Efforts to replace this are underway.

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

Most vehicles now generally use wipers to remove contaminants. However, the wiper repeatedly moves on the windshield while driving and not only obstructs the driver's field of view, but also has a limited arc area. In addition, when the wiper is aging, friction noise is generated and the removal ability is reduced, so that the wiper needs to be replaced regularly.

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

In addition, in order to keep the field of view of the compact camera clear, droplets generated on the lens surface must be immediately removed. For this purpose, the cleaning device is continuously driven, which not only generates unnecessary power consumption but also reduces the life of the cleaning device.

Therefore, there is a need for a cleaning device capable of removing droplets with a small power, particularly a cleaning device having a 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 above-described problems of the prior art, and to provide a technique for removing the droplet (droplet), dust or frost formed on the glass of a vehicle or a camera by applying the electrowetting technology.

In addition, the present invention is to provide a camera droplet detection device and method for detecting a droplet (droplet) generated on the surface of the camera cover glass using the impedance of the camera cover glass or the image photographed by the camera.

In addition, the present invention provides a cleaning device and method for removing conductive droplets formed on a surface using an electrowetting-on-dielectric principle, and removing non-conductive droplets formed on a surface using a dielectrophoresis principle. To provide.

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

In order to achieve the above object, a cleaning device according to an embodiment of the present invention comprises a substrate; At least one electrode arranged on the substrate; An insulating film arranged on the electrode; And a hydrophobic film arranged on the insulating film. Here, the hydrophobic film contains a fluorine-based material and a silane-based material.

Hydrophobic film production method used in the cleaning apparatus according to an embodiment of the present invention comprises the steps of heating the hydrophobic material containing a fluorine-based material and silane-based material to generate steam; And depositing the generated vapor on a structure in which a pattern and an insulating film are sequentially formed on a substrate.

According to one embodiment of the present invention, it is possible to provide a smart self-cleaning glass for a vehicle that can quickly and effectively remove contaminants such as rainwater, dust, frost, etc. generated in the 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 rate 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 the visibility of the vehicle even in an environment such as bad weather to help the driver's safe driving, and also to reduce the weight and air resistance of the vehicle and contribute to improving the fuel efficiency of the vehicle.

Camera droplet detection apparatus and method according to an embodiment of the present invention, it is possible to detect a droplet (droplet) generated on the surface of the camera cover glass using the impedance of the camera cover glass or the image taken by the camera.

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

In addition, by applying the electrowetting technology and the electrophoretic technology, it has the advantage of fast response speed and low energy consumption, and accordingly various fields such as the vehicle's windshield, the image sensor of the IoT device as well as the compact camera for the vehicle or mobile May be applied or used.

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 may have a stronger durability than the existing hydrophobic film.

1 is a view showing the configuration of a vehicle glass cleaning device according to an embodiment of the present invention.
2 and 3 are views showing the configuration of a vehicle glass cleaning device according to an embodiment of the present invention.
4 is a flowchart illustrating a vehicle glass cleaning process according to an embodiment of the present invention.
5 is a flowchart illustrating a vehicle glass cleaning process according to another embodiment of the present invention.
6 is a diagram illustrating an actual cleaning process of a vehicle glass cleaning apparatus according to another embodiment of the present invention.
7 is an actual use scene of the vehicle glass cleaning apparatus according to the embodiment of the present invention.
8 is a view illustrating a droplet removal process of the cleaning device according to an embodiment of the present invention.
9 is a view 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 exemplary embodiment of the present invention.
FIG. 11 is a view illustrating the flow of droplets upon removal of droplets according to one embodiment of the invention. FIG.
12 is a view showing a change in droplet contact angle when removing the droplets according to an embodiment of the present invention.
13 is a diagram showing the results of a drop removal experiment.
14 is a view schematically showing an electrode of a cleaning device according to another embodiment of the present invention.
15 is a view illustrating a droplet removal process of the cleaning device according to an embodiment of the present invention.
16 is a diagram illustrating an electrode pattern according to an exemplary embodiment of the present invention.
17 is a view showing the flow of droplets when removing the droplets according to an embodiment of the present invention.
18 is a view illustrating a change in droplet contact angle when removing droplets according to an embodiment of the present invention.
19 is a view illustrating the flow of droplets when removing the droplets according to another embodiment of the present invention.
20 and 21 are diagrams showing the results of droplet removal experiments.
22 is a diagram schematically illustrating a configuration of a camera droplet detecting apparatus according to an embodiment of the present invention.
FIG. 23 is a diagram illustrating an example of impedance change of the camera cover glass with and without droplets. FIG.
24 is a diagram illustrating an example of an image photographed when a droplet is generated on the 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 view showing 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 flowchart illustrating a cleaning method according to an embodiment of the present invention.
35 is a view schematically showing the structure of a cleaning device according to an embodiment of the present invention.
36 is a view schematically illustrating a process of manufacturing a hydrophobic film according to an embodiment of the present invention.

As used herein, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise. In this specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or some steps It should be construed that it may not be included or may further include additional components or steps. In addition, the terms "... unit", "module", etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. .

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device capable of self-removing drops, dust, frost, and the like, such as liquids such as rainwater and fog, and a method for removing droplets. The cleaning device may be a single device or a device coupled to another device.

According to an embodiment, the cleaning device may be a device including an external glass, for example, a camera of a vehicle, 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 the devices for which the droplets need to be removed.

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

Of course, the cleaning structure is not limited to the camera, the window of the vehicle as long as it can remove the droplets may be variously modified.

Such a cleaning device is exposed to the external environment, and as a result, droplets such as rain water 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 controlling a specific function of the vehicle based on the image of the camera, the degradation of the image quality due to the droplets may be a cause of the vehicle accident.

In addition, since the rainwater is removed using a wiper when the front windshield of the vehicle is attached, the risk of an accident may be increased when the wiper is replaced late.

Therefore, the removal of the droplets is necessary as soon as the droplets are attached to the surface, and the present invention proposes a cleaning device capable of removing droplets immediately when the droplets are attached to the surface.

It is also a technique that can substitute the wiper for removal of the droplet as soon as it is attached to the surface without replacement. The present invention proposes a cleaning structure that can lower the risk of an accident while removing droplets immediately when the droplets adhere to the surface.

According to one embodiment, the cleaning device removes droplets, dust or frost using an electrowetting technique. In particular, the cleaning device may remove droplets, dust or frost on the surface by applying a specific voltage to the electrode. Here, the method of applying the specific voltage includes an AC method of applying a specific voltage to all the electrodes at once and a DC method of sequentially applying a specific voltage to the electrodes.

In another aspect, the cleaning device may generate vibrations on the surface to remove the droplets. When vibration is generated on the surface of the cleaning device, the adhesion between the droplet and the surface is weakened so that the droplet can 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 by gravity, so that the droplet It may be removed from the cleaning device and removed.

From a vehicle control point of view, rain can attach 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 battery of the vehicle. The controller may be one of an ECU (Electronic control unit) 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 not limited to droplets, and not only droplets (including fine droplets) but also dust, frost, etc. can be removed.

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

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

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

As one embodiment of cleaning the vehicle glass, the vehicle glass cleaning device 100 may change the surface tension of the droplet by applying a voltage to each electrode by varying the conditions of the direct current voltage (high, ground). .

In this case, as shown in FIG. 1, the droplets move in the direction of the electrode to which the high voltage is applied from the ground voltage (and eventually the outside of the vehicle glass).

As another embodiment of cleaning the vehicle glass, the vehicle glass cleaning device 100 may change the surface tension of the droplet by applying a low frequency alternating voltage to the electrode to cause the droplet to vibrate.

Since the vehicle glass has a predetermined inclination with respect to the plane, the droplets vibrate and move downwards (in the end of the vehicle glass).

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

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

The vehicle glass cleaning device 100 includes a windshield glass (substrate) 110, an electrode 120, an insulating layer 130, a hydrophobic layer 140, and a direct current voltage. The applicator 150 may be included.

The vehicle glass 110 serves as a substrate of the vehicle glass cleaning device 100 as a lowermost layer of the vehicle glass cleaning device 100.

Meanwhile, the electrode 120 may be continuously disposed on the upper surface of the vehicle glass 110 as a transparent electrode to form a specific pattern.

Here, the electrode 120 may have a straight line, 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 illustrated 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 Ferylene C, Teflon, and a metal oxide film.

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

Thus, droplets can easily migrate on the surface of hydrophobic layer 140.

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

At this time, the droplets are moved in the direction of the electrode to which the high voltage is applied from the electrode to which the ground voltage is applied, on the surface of the hydrophobic layer 140, and eventually to the outermost side of the hydrophobic layer 140, thereby the vehicle glass 110 may be cleaned.

As another embodiment of the vehicle glass cleaning device 100, as shown in FIG. 3, the vehicle glass cleaning device 100 may include a cover glass 110, an electrode 120, an insulating layer 130, and a hydrophobic layer 140. ) And an AC voltage applying unit 160.

That is, in the vehicle glass cleaning device 100 according to another embodiment, the cover glass 110, the electrode 120, the insulating layer 130, and the hydrophobic layer 140 are all the same, and the DC voltage applying unit 150 is the AC voltage. It is replaced by the applicator 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 may vibrate when an AC voltage is applied to the electrode 120.

At this time, due to the inclination of the vehicle glass 110, the droplets may move to the outside of the hydrophobic layer 140 along the inclination so that the vehicle glass 110 may be cleaned.

As another embodiment of the vehicle glass cleaning device 100, the vehicle glass cleaning device 100 may include a cover glass 110, an electrode 120, an insulating layer 130, a hydrophobic layer 140, and a DC voltage applying unit ( 150, an AC voltage applying unit 160, and a voltage mode selector (not shown).

That is, the vehicle glass cleaning device 100 according to another embodiment may include the cover glass 110, the electrode 120, the insulating layer 130, the hydrophobic layer 140, the DC voltage applying unit 150, and the AC voltage applying unit ( 160 are all the same, and a voltage mode selection unit (not shown) is added.

The voltage mode selection unit (not shown) determines whether to remove the droplets by applying a DC voltage to the electrode 120 or applying an alternating voltage to the electrode 120 according to a situation in which the vehicle glass is installed. According to a user's selection, a voltage may be applied to the electrode 120 using any one of the DC voltage applying unit 150 and the AC voltage applying unit (not shown).

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

In FIGS. 4 and 5, the vehicle glass cleaning device 100 is coupled to an electronic system of a vehicle that can be operated by a driver. Hereinafter, the vehicle glass cleaning device 100 illustrated in FIGS. 2 and 3 is mainly used. The flowcharts of FIGS. 4 and 5 will be described.

The vehicle glass cleaning device 100 receives a drop removal request signal through an electronic system operated by a driver (S410 and S510).

After S410, the vehicle glass cleaning apparatus 100 sequentially applies alternating ground and high DC voltages to the electrodes 120 at predetermined intervals according to the input drop removal request signal (S420). ).

In this case, the droplets formed on the surface of the hydrophobic layer 140 alternately move between the ground and the high to move to the outside of the hydrophobic layer 140 by a DC voltage applied to each electrode 120. 110 may be cleaned.

As another embodiment, as shown in FIG. 5, when an alternating voltage is applied to the electrode 120 after the step S510, the droplets formed on the surface of the hydrophobic layer 140 may vibrate due to the application of the alternating voltage. The vehicle glass 110 may be cleaned by moving toward the outside of the hydrophobic layer 140 along the inclination of the vehicle glass 110.

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

6 is a diagram illustrating an actual cleaning process of a vehicle glass cleaning apparatus 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 vehicle glass 110.

Referring to FIG. 6, the vehicle glass cleaning apparatus 100 according to the exemplary embodiment of the present invention may roll or drop droplets even on a surface to which dust is attached. At this time, since the droplets adsorb the surrounding dust while moving, the dust attached to the surface can be removed at the same time as the droplet is removed.

In addition, since the vehicle glass cleaning device 100 according to the embodiment of the present invention generates heat in the electrode 120 in the same principle as the heat wire of the insulator, frost generated on the surface may be removed.

7 is an actual use scene of the vehicle glass cleaning apparatus according to the embodiment of the present invention.

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

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

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

8 is a view showing a droplet removal process of the cleaning device according to an embodiment of the present invention, Figure 9 is a view 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, Figure 11 is a view showing the flow of droplets when removing the droplets according to an embodiment of the present invention. FIG. 12 is a view showing a change in droplet contact angle when removing droplets according to an exemplary embodiment of the present invention, and FIG. 13 is a view illustrating droplet removal experiment results.

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

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

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

In particular, since the glass structure of the present invention uses an electrowetting technique, the droplets can be quickly removed due to the fast response speed due to the characteristics of the electrowetting technique.

The cleaning device for removing such droplets, in particular the part 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 900, an electrode 902, an insulating film 904, and a hydrophobic film 906.

The base layer 900 may be a cover glass that protects the cleaning device from external contamination and impact, and may be arranged, for example, on 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 with a predetermined pattern.

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

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 a power source 908 or ground, from which a specific voltage is applied to the first base pattern 1010. On the other hand, the power source 908 may be located inside or outside the cleaning device.

The first branch pattern 1012 extends from the first base pattern 1010 in a direction crossing 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 the 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 cross each other.

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 a power source 908 or ground, from which a specific voltage is applied to the second base pattern 1022.

The second branch pattern 1020 extends from the second base pattern 1022 in a direction crossing 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.

In addition, the second branch patterns 1020 are arranged to intersect with 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 the intervals between the second branch patterns 1020 may be the same. Of course, some of the intervals between the second branch patterns 1020 may be different as long as the first branch patterns 1012 and the second branch patterns 1020 cross each other.

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, an insulating film 904 is arranged over the electrode 902 and may fill the gap between the electrodes 1000 and 1002.

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

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

The cleaning operation of a cleaning device having such a structure will be described.

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

As the surface of the cleaning device vibrates, the adhesion between the surface and the droplets decreases. In this case, since the surface of the cleaning device is inclined in the direction of gravity, droplets attached to the surface are slid in the direction of gravity as shown in FIG. 11 and are separated from the cleaning device. That is, the droplets are 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 exemplary embodiment, when the droplet is vibrated, a change in the moving direction of the droplet, a change in the contact angle in a direction opposite to the moving direction, and a change in the contact angle in the other direction may be different. This difference can be useful for slipping droplets. In addition, due to the difference in the change of the contact angle, the droplet may be removed by sliding in the direction of gravity despite the low inclination of the surface of the cleaning device.

According to another embodiment, the electrodes 1000 and 1002 may have a comb-tooth 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 contact angle change 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 droplets slide and the grain direction of the electrodes 1000 and 1002 coincide or are similar, and as a result, the droplets are more easily slipped upon droplet vibration. Thus, even if a lower voltage is applied to the electrodes 1000 and 1002, the droplet can be easily removed.

In other respects, when the cleaning device implements a cleaning device in which the contact angle change of the droplet in the sliding direction, that is, the gravity direction is larger than the contact angle change in the other direction, the droplet may be easily removed.

Below, we will look at the actual experimental results.

As a result of actual experiment while driving after mounting a general camera and a camera to which the cleaning device of the present invention is applied to a vehicle on a rainy day, droplets (rainwater) on the surface of the camera to which the cleaning device is applied as shown in FIG. By removing the image, it can be confirmed that the image is captured much more clearly.

In addition, as a result of the actual experiment of the vehicle using the glass structure as the windshield on a rainy day, as shown in FIG. 13B, the droplets of the front windshield may be completely removed, and the front windshield may be cleared.

14 is a view schematically showing an electrode of a cleaning device according to another embodiment of the present invention. However, since the electrodes are the same in structure only in the arrangement direction, only one electrode is illustrated. 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 portion 1412 protruding from the branch portion 1410. That is, unlike the branch pattern of FIG. 10, the branch pattern 902 of the present embodiment may include at least one protrusion 912. When the protrusion 912 is formed, the entire surface area of the electrode may be widened.

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

According to one embodiment, the cleaning device may include a vibrating unit for vibrating the droplets attached to the surface to reduce the adhesion of the droplets and the surface of the cleaning device. The vibrator has a specific pattern. In addition, the surface of the cleaning device is inclined in the direction of gravity, the grain of the pattern is the same as the direction of movement of the droplet can be moved along the grain.

Of course, the change in contact angle of the droplet in the direction opposite to the movement direction and the movement direction may be larger than the change in the contact angle in the other direction according to the vibration.

According to another embodiment, the cleaning device may include a vibrating unit which vibrates a droplet attached to the surface of the cleaning device to reduce the 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 in response to the vibration, the change in the contact angle of the droplet in the direction of movement or in the opposite direction to the movement direction is larger than the change in the contact angle of the droplet in the other direction. Can be.

Meanwhile, the vibrator includes an electrode, and the grain of the electrode may be the same as the moving direction of the droplet.

According to another embodiment, the cleaning structure may include a base layer, a first electrode and a second electrode arranged on the base layer, and a droplet support layer arranged on the electrodes. Here, the droplet support layer may include an insulating film and a hydrophobic film. 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 comprises 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 the change in contact angle of the droplet in the moving direction is different from the change in contact angle of the droplet in the other direction when the droplet moves on the droplet support layer as the droplet moves.

According to yet another embodiment, the cleaning structure comprises a base layer, an electrode arranged on the base layer and a droplet support layer arranged on the electrode. Here, the movement direction and the grain direction of the electrode or the droplet support layer during the movement of the droplet on the droplet support layer is the same.

15 is a view illustrating a droplet removal process of the 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, Figure 17 is a view showing the flow of droplets when removing the droplets according to an embodiment of the present invention. FIG. 18 is a view illustrating a change in droplet contact angle when removing droplets according to an embodiment of the present invention, and FIG. 19 is a view illustrating droplet flow when removing droplets according to another embodiment of the present invention. 20 and 21 are diagrams showing the results of droplet removal experiments.

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

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, the number of the first sub electrodes 1600a to 1600n and the number of the second sub electrodes 1602a to 1602n are preferably the same, but may be different.

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

Hereinafter, the structures 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 a representative. 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 transmits 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 a power source 908 or ground. As a result, a specific voltage is input to the first input pattern 1612. On the other hand, 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 part of the first base pattern 1610. Accordingly, a portion 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 extends from the first base pattern 1610 in a direction crossing 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 the intervals between the first branch patterns 1614 may be the same. Of course, some of the gaps 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 transfers 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 a 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, in which case a specific voltage may be input as 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 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.

In addition, the second branch patterns 1624 are arranged to intersect with 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 the intervals between the second branch patterns 1624 may be the same. Of course, some of the intervals between the second branch patterns 1624 may be different as long as the first branch patterns 1614 and the second branch patterns 1624 intersect.

According to the intersection, the second branch patterns 1624 are physically separated from each other and arranged between the first branch patterns 1614, and the first branch patterns 1614 are physically separated from each other. 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. Can be. Here, the first voltage may be a positive voltage and the second voltage may be a ground voltage.

Referring again to FIG. 9, an insulating film 904 is arranged over the electrode 902 and may fill the gap between the electrodes 1600 and 1602.

The cleaning operation of 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 drop removal command, the power source 908 applies a first voltage to one of the electrodes 1600 and 1602 under the control of the controller, and a second lower than the first voltage to the other electrode. Apply voltage. As a result, the droplets attached to the surface of the cleaning device vibrate. 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 droplets decreases. In this case, since the surface of the cleaning device is inclined in the direction of gravity, droplets attached to the surface slide out in the direction of gravity as shown in FIG. 17. That is, the droplets are 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 one embodiment, the change in the contact angle in the opposite direction of the movement direction and the movement direction of the droplet during the vibration of the droplet may have a different contact angle change in the other direction. This difference can be useful for slipping droplets. In addition, due to the difference in the change of the contact angle, the droplet may be removed by sliding in the direction of gravity despite the low inclination of the surface of the cleaning device.

According to another embodiment, the electrodes 1600 and 1602 may have a comb-tooth 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 contact angle change 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 droplets slide and the grain direction of the electrodes 1600 and 1602 coincide or are similar, and as a result, the droplets are more easily slipped upon droplet vibration. Thus, even if a lower voltage is applied to the electrodes 1600 and 1602, the droplet can be easily removed.

In other respects, when the cleaning device implements a cleaning device in which the contact angle change of the droplet in the sliding direction, that is, the gravity direction is larger than the contact angle change in the other direction, the droplet may be easily removed.

Next, the cleaning operation through the direct current method will be described.

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

For example, a first voltage having 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. 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 first 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 in 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.

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 attached to the surface of the cleaning device can be easily removed.

On the other hand, in the direct current method, the change in the contact angle of the droplet in the moving direction of the droplet may be larger than the change in the contact angle in the opposite direction to the moving direction.

Below, 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 actual experiment while driving the cleaning device of the present invention after driving on a rainy day, as shown in FIG. 20 (a), droplets (rainwater) on the surface of the cleaning device are removed to make the image much clearer. You can confirm that it was taken. In particular, as shown in Figure 20 (a), it can be seen that not only the droplets but also the dust is removed at the same time.

In addition, as a result of the actual experiment of the vehicle using the glass structure as the front window on a rainy day, as shown in (b) of FIG. 20, the droplets of the front window can be completely removed to confirm that the front window 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 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 can remove droplets, dust or frost.

According to one embodiment, the cleaning device may include a vibrating unit for vibrating the droplets attached to the surface to reduce the adhesion of the droplets and the surface of the cleaning device. The vibrator has a specific pattern. In addition, the surface of the cleaning device is inclined in the direction of gravity, the grain of the pattern is the same as the direction of movement of the droplet can be moved along the grain.

FIG. 22 is a diagram schematically illustrating a configuration of a camera droplet detecting apparatus according to an embodiment of the present invention, FIG. 23 is a diagram illustrating an impedance change of a camera cover glass according to whether droplets are present, and FIG. 24 is a camera cover It is a figure which shows the example of the image | photographed when the droplet generate | occur | produced on glass. Hereinafter, a configuration of an apparatus for detecting a camera droplet according to an exemplary embodiment of the present invention will be described with reference to FIG. 22, with reference to FIGS. 23 and 24.

First, referring to FIG. 22, the camera droplet detecting apparatus according to the exemplary embodiment of the present invention includes a camera unit 10, an impedance measuring unit 20, a controller 30, and a voltage applying unit 40.

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

The camera module 11 photographs a subject through a lens to generate an image. For example, the camera module 11 is composed of a transparent material, such as glass made of spherical or aspherical, lens module for converging or diverging light to generate an optical image, the generated optical image It may be configured to include an image sensor for converting into a signal, a PCB including various circuits for processing the electrical signal generated by the image sensor.

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 serves as a lowermost layer of the camera cover glass 15 and directly covers the lens of the camera module 11 and serves as a substrate of the camera cover glass 15.

The transparent electrodes 17 are continuously arranged on the upper surface of the cover glass layer 16 to form a preset pattern. For example, the transparent electrode 17 can have a straight, streamlined or annular shape. The form of the pattern formed by the plurality of transparent electrodes 17 is not limited.

The hydrophobic insulating layer 18 is the uppermost layer of the camera cover glass 15, and is stacked on the top surfaces 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 one or more materials selected from the group consisting of Ferylene C, Teflon, and metal oxide films.

In addition, the hydrophobic insulating layer 18 has droplets formed on its surface.

For example, hydrophobic insulating layer 18 may be comprised of a material that is less compatible with fluids such as water, such that droplets can easily migrate from the surface of hydrophobic insulating layer 18.

The impedance measuring unit 20 measures the impedance of the transparent electrode 17. To this end, a minute voltage may be constantly applied to the transparent electrode 17 by the voltage applying unit 40. For example, a ground voltage and a high voltage, which are direct current voltages, may be minutely applied to the two transparent electrodes 17.

The controller 30 determines whether droplets are generated on the camera cover glass 15 using the impedance of the transparent electrode 17 measured by the impedance measuring unit 20 or the image photographed by the camera module 11.

That is, the controller 40 checks the impedance of the transparent electrode 17 measured by the impedance measuring unit 20, and when the impedance changes, may determine that droplets are generated on 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 layer 18 of the camera cover glass 15 may have a resistance component and a capacitor, respectively. ) May have a component. As shown in the right side of FIG. 23, the droplets generated on the surface of the hydrophobic insulating layer 18 of the camera cover glass 15 may have a resistance component and a capacitor component. Therefore, when droplets are generated on the hydrophobic insulating layer 18 surface of the camera cover glass 15, the impedance of the transparent electrode 17 at the position where the droplets are generated changes.

In addition, the controller 40 may analyze the image photographed by the camera module 11, and as a result of the analysis, when the image is distorted in a predetermined circular shape, the controller 40 may determine that droplets are generated on the camera cover glass 15. . For example, as illustrated in FIG. 24, when a large number of droplets are generated on the camera cover glass 15, the photographed image may be distorted in a shape of a certain circle.

In this case, the controller 40 may check the existence of the circular droplet shape in the image or calculate the sharpness of the image in order to determine that the image is distorted in a certain circular shape.

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

When the droplets are generated on the camera cover glass 15, the controller 30 controls the voltage applying unit 40 to apply a voltage to the transparent electrode 17.

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

That is, the voltage applying unit 40 may alternately apply the ground and the high voltage, which are DC voltages, to the transparent electrodes 17 in sequence at predetermined intervals.

For example, the droplets travel on the surface of the hydrophobic insulating layer 18 in the direction of the high voltage applied electrode at the electrode to which the ground voltage is applied, and eventually to the outermost side of the hydrophobic insulating layer 18. By doing so, 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 alternating current voltage is applied to the transparent electrode 17, droplets formed on the surface of the hydrophobic insulating layer 18 vibrate due to the alternating voltage applied to the transparent electrode 17. Then, the droplets move to the outermost side of the hydrophobic insulating layer 18 along the inclination due to the vibration and the inclination of the camera cover glass 15, whereby the camera cover glass 15 may be cleaned.

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

In operation S2500, the camera droplet detecting apparatus measures the impedance of each transparent electrode 17 of the camera cover glass 15.

In operation S2502, the camera droplet detecting apparatus checks whether the measured impedance of the transparent electrode 17 changes.

In operation S2504, when the impedance of the transparent electrode 17 is changed, the camera droplet detecting apparatus determines that the droplet is detected.

In operation S2506, the camera droplet detecting apparatus 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 operation S2600, the camera droplet sensing apparatus photographs an image through the camera module 11.

In operation S2602, the camera droplet detecting apparatus analyzes the captured image.

In operation S2604, as a result of analyzing the photographed image, the camera droplet detecting apparatus determines that the droplet is detected when the image is distorted in a predetermined circular shape.

Here, the camera droplet detection apparatus checks the existence of a circular droplet shape in the image, or after calculating the sharpness of the image, when a large number of circular droplet shapes are found in the image, or the sharpness of the image is less than the predetermined reference sharpness, It can be determined that the image is distorted in the shape of a certain circle.

In operation S2606, the camera droplet detecting apparatus removes the droplet by applying a voltage to the transparent electrode 17 as the droplet is detected.

27 is a view showing a cleaning device according to an embodiment of the present invention, Figure 28 is a view showing 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 the cover glass of the camera lens as shown in FIG. 27. Of course, the cleaning device according to the embodiment of the present invention can be applied to not only the cover glass of the camera lens, but also to an object that requires the removal of droplets formed on the surface, such as the vehicle windshield, and in the following, For convenience, it will be described on the assumption that the cleaning device 100 according to the embodiment of the present invention is applied to the cover glass of the 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 direct voltage or an alternating 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 the droplet by applying a voltage to each electrode under different DC voltage conditions (high and ground). In this case, the droplets move in the direction of the electrode to which the ground voltage is applied at a high voltage (and eventually outside of the cover glass of the camera lens).

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

In particular, the cleaning device 100 according to the embodiment of the present invention applies a low frequency AC voltage together with a high frequency AC voltage on the basis of a preset frequency to a plurality of electrodes to remove not only conductive droplets but also non-conductive droplets. That is, the cleaning device applies a high frequency alternating voltage to the plurality of electrodes and switches the applied high frequency alternating voltage on / off at a low frequency with respect to the high frequency alternating voltage, thereby providing a high frequency alternating voltage and a low frequency alternating voltage to the plurality of electrodes. Is applied simultaneously to remove both non-conductive and conductive droplets.

For reference, when only a low frequency voltage is applied to the plurality of electrodes, the conductive droplets are periodically vibrated at a low frequency due to the surface tension being periodically changed, but the non-conductive droplets are not changed.

In addition, when only a plurality of high frequency voltages are applied to the electrodes, the conductive droplets periodically oscillate at a high frequency due to the surface tension being periodically changed, but they do not move but spread flat on the surface, and the non-conductive droplets change the surface tension. It spreads flat and does not vibrate or move.

On the other hand, when the high frequency AC voltage applied to the plurality of electrodes is switched on / off at a low frequency, both the conductive droplets and the non-conductive droplets spread on the surface and flatten repeatedly to vibrate. By moving it, it can be removed.

A plurality of electrodes according to an embodiment of the present invention is divided into a plurality of high voltage electrode and a plurality of ground voltage electrode, the high voltage and ground voltage electrode is the cover of the camera lens It is arranged continuously so that they are separated from each other on the glass surface. In this case, the plurality of high voltage electrodes and the plurality of ground voltage electrodes may be integrally formed, and thus the high voltage electrodes and the ground voltage electrodes may be connected to each other.

For example, referring to FIG. 28, each of the high voltage electrode and the ground voltage electrode has a comb shape and may be disposed in an interlocked form without touching each other.

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

According to an embodiment of the present invention, a cleaning device includes glass (Substrate) 2900, an electrode 2902, a dielectric layer 2904, a hydrophobic layer 2906, and a voltage. The application unit 2908 and the switching unit 2910 are included.

The glass 2900 serves as a substrate of the cleaning device as the lowest layer of the cleaning device.

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

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

Meanwhile, as illustrated in FIG. 29, the insulating layer 2904 may be stacked on the top surface of the electrode 2902, and may fill a gap between the electrodes 2902.

For reference, the insulating layer 2904 may include at least one material selected from the group consisting of Ferylene C, Teflon, and a metal oxide film.

Meanwhile, the hydrophobic layer 2906 is a top layer of the cleaning device, and droplets are formed on the surface, and may be made of a material having low affinity with a fluid such as water. Thus, droplets can easily migrate at the surface of hydrophobic layer 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 the high frequency AC voltage on / off 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 period 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.

As such, by switching the switching unit 2910 on / off the high frequency AC voltage, a low frequency AC voltage may be generated, and the conductive droplets and the non-conductive droplets formed on the surface of the hydrophobic layer 2906 are high frequency AC. The voltage and the low frequency alternating current voltage are simultaneously applied to the electrode 120, thereby vibrating.

At this time, if the glass 2900 has a predetermined inclination with respect to the plane, the droplet is moved along the inclination due to the inclination of the glass 110 to the outside of the hydrophobic layer 2906, the glass 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) for simultaneously generating 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. Thus, as the high frequency voltage and the low frequency voltage are applied to the electrode 2902, both the conductive droplet and the non-conductive droplet are removed, so that the glass 2900 can be cleaned.

For example, referring to FIG. 30, when the 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 layer 2906 is formed. This repeatedly changes, which causes both the nonconductive droplets and the conductive droplets to oscillate regularly.

That is, the conductive droplet is vibrated by the electrowetting (on-dielectric) principle when a low frequency alternating voltage is applied to the electrode 2902, and the non-conductive droplet is subjected to dielectric electrophoresis when a high frequency alternating voltage is applied to the electrode (120). vibrates by the principle of (dielectrophoresis). Here, the principle of dielectrophoresis is a phenomenon in which when a particle having no polarity is exposed to a non-uniform alternating electric field, a dipole is induced to the particle and the force of the electric field is applied in a large or small direction.

For example, referring to FIG. 31, as shown in FIG. 31A, the surface tension may be 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. . And, as shown in (b) of FIG. 31, the non-conductive droplet may change the surface tension according to the principle of electrophoresis, thereby changing the contact angle between the droplet and the surface of the hydrophobic layer 2906.

As such, when droplets generated on the surface of the hydrophobic layer 2906 vibrate, adhesion between the droplet and the surface of the hydrophobic layer 2906 is reduced. Thus, when the surface of the hydrophobic layer 2906 is inclined, when the cleaning apparatus according to the embodiment of the present invention is driven, as shown in FIG. 32, droplets generated on the surface of the hydrophobic layer 2906 are moved downward by gravity. I can slide and move. (A) of FIG. 32 shows that a conductive droplet vibrates and slips, and (b) shows that a nonconductive droplet vibrates and slips.

And, if the surface of the hydrophobic layer 2906 is inclined, when a droplet generated on the surface of the hydrophobic layer 2906 vibrates, a difference occurs between the contact angle of the moving direction portion of the droplet and the contact angle of the portion opposite to the moving direction. This difference helps the droplets slide down and may cause the droplets to slip on the surface of the hydrophobic layer 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 ( Larger in the grain direction of 2902). And, the difference in contact angles in the opposite direction to the moving direction that occurs when the droplet vibrates on the inclined surface also occurs larger in the grain direction. Thus, as described above, because the contact angle difference in the opposite direction to the movement of the droplet helps the slide to slide, matching the direction in which the droplet slips with the grain direction of the electrode 2902 results in a lower voltage. It can slide quickly.

As such, in the cleaning apparatus according to the embodiment of the present invention, not only the grain direction of the electrode but also the frequency of the on / off switching is affected in controlling the droplets. Therefore, since each droplet has a specific natural frequency according to the size, when a voltage having a frequency corresponding to the specific natural frequency according to the size of the generated droplet is applied, the droplet vibrates more significantly, thereby causing the droplet to form a hydrophobic layer ( 2906) it may slide better on the surface.

34 is a flowchart illustrating a cleaning method according to an embodiment of the present invention.

In FIG. 34, the cleaning device according to an embodiment of the present invention may be coupled to a camera module (not shown) (eg, AVMS: Around View Monitoring System) of the vehicle. Hereinafter, the cleaning device shown in FIG. 34, the flow chart of FIG. 34 will be mainly described.

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

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

In operation S3420, the cleaning device turns on or off the high frequency AC voltage at a low frequency with respect to the applied high frequency AC voltage. At this time, the high frequency AC voltage is turned on / off, so that a low frequency AC voltage may be generated, and the conductive and non-conductive droplets formed on the surface of the hydrophobic layer 2906 may have high frequency AC voltages and low frequency AC voltages. Applied simultaneously to 2902, it vibrates.

In addition, the non-conductive droplets and the conductive droplets slide down along the inclination of the glass 2900 to move outward of the hydrophobic layer 2906, so that the glass 2900 can be cleaned.

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

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

Hydrophobic films used for electrowetting generally consist of fluorine-based materials. However, such a hydrophobic film is excellent in hydrophobic properties but weak in durability, and therefore, once installed, it may not be suitable for cleaning devices used in automobiles, cameras, and the like, which have to be used for a long time. The present invention proposes a hydrophobic film having excellent durability as well as hydrophobic characteristics.

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

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

Since the remaining components except for the hydrophobic film 3506 have been described above, a description thereof will be omitted.

The hydrophobic film 3506 can have excellent hydrophobic properties and strong durability.

According to an embodiment, the hydrophobic film 3506 may be a silane-based material that helps the organic material and the inorganic material material to be bonded to a fluorine-based material (including a fluorine compound containing a fluorine atom) having water repellency, oil repellency, and chemical resistance properties. Organic-inorganic silane compounds).

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

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

According to an embodiment, the fluorine compound may contain 49 at% or more of fluorine atoms on the surface thereof such that the surface is hydrophobic. The fluorine compound may be a polymer having a chemical formula of -CxFy-, CxFyHz-, -CxFyCzHp-, -CxFyO-, -CxFyN (H)-and the like, wherein x, y, z, and p are natural numbers, respectively, and are amorphous. Fluorine compounds, for example AF1600. Here, the surface of the hydrophobic film 3506 may mean a thin film from a top surface of the hydrophobic film 3506 to a distance of 50 angstroms to 100 angstroms in the downward direction.

According to one embodiment, the organic-inorganic silane compound may be an organic-inorganic silane compound having at least one amino group, vinyl group, epoxy group, alkoxy group, halogen group, mercapto group, sulfide group 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 -Aminopropyl diethoxysilane, vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri (methoxyethoxy) silane, di-, tri- or tetraalkoxysilane, vinyl methoxysilane, vinyl trimethoxysilane, Vinyl epoxy silane, Vinyl tri epoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-methacryloxy propyl trimethoxy silane, (gamma)-glycidoxy propyl triethoxy silane, (gamma)-methacryloxy propyl trimeth Oxysilane, chlorotrime Silane, trichloroethylsilane, trichloromethylsilane, trichlorophenylsilane, trichlorovinylsilane, mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, bis (trimethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) disulfide, (methacryloxy) propyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and combinations thereof, Preferably aminopropyltriethoxysilane or a combination comprising the same.

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

In addition, the hydrophobic film 3504 maintains a contact angle of 113 degrees even after applying 1500 eraser frictions under a load of 500 g using an eraser anti-wear test equipment, and has a duration of at least 1 year. For example, Teflon, Cytop) was confirmed to have a very excellent durability.

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

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

The heating device 3610 and the 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 make the hydrophobic material into steam by applying heat. Vapor generated by the heating apparatus is deposited into the object 3612, resulting in a hydrophobic film 3504 over the object 3612.

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

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

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

Unlike a cleaning device using a hydrophobic film made of fluorine material in which droplets are well removed when a voltage having a frequency of tens or hundreds of hertz is applied in a pattern, a cleaning device using the hydrophobic film 3504 manufactured as described above is thousands of hertz. The droplets can be removed well when applying a voltage having a frequency of.

On the other hand, the components of the above-described embodiment can be easily identified from a process point of view. That is, each component can be identified as a separate process. In addition, the process of the above-described embodiment can be easily understood in terms of the components of the apparatus.

The embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having various 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. Should be regarded as belonging to the following claims.

100: vehicle glass cleaning appliance
110: vehicle glass
120: electrode
130: insulation layer
140: hydrophobic layer
150: DC voltage applying unit
160: AC voltage applying unit

Claims (9)

Board;
At least one electrode arranged on the substrate;
An insulating film arranged on the electrode;
A hydrophobic film formed to have a thickness of several tens of nanometers and arranged on the insulating film;
A voltage applying unit configured to apply a high frequency AC voltage to the electrode based on a preset reference frequency; And
It includes a switching unit for generating both a high frequency voltage and a low frequency voltage in a period by on / off switching the applied high frequency AC voltage at a low frequency period based on the reference frequency,
The hydrophobic layer includes a fluorine-based material and a silane-based material, and is configured to have a contact angle with a droplet of at least 113 degrees, wherein the fluorine-based material contains an amorphous fluorine chemical containing at least 49 wt% of fluorine atoms to make the hydrophobic layer hydrophobic. This,
The silane-based material comprises a functional organic-inorganic silane compound comprising at least one of an amino group, an epoxy group, an alkoxy group, a halogen group, a mercapto group and a sulfide group.
delete The method of claim 1,
The organic-inorganic silane compound is aminopropyltriethoxysilane, aminopropyltrimethoxysilane, amino-methoxysilane, phenylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltridimethoxysilane, γ-aminopropyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyldie Methoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri (methoxyethoxy) silane, di-, tri- or tetraalkoxysilane, vinylmethoxysilane, vinyltrimethoxysilane, vinylepoxysilane, Vinyltriepoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, chloro Trimethylsilane, trichloro Tylsilane, trichloromethylsilane, trichlorophenylsilane, trichlorovinylsilane, mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, bis (trimethoxysilylpropyl) amine, bis (3-tri Ethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) disulfide, (methacryloxy) propyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glyci A cleaning device selected from doxypropylmethyldiethoxysilane, 3-glycidoxypropyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and combinations thereof. The cleaning apparatus as claimed in claim 1, wherein the hydrophobic film is formed by depositing steam generated by heating a hydrophobic material in a vacuum chamber on a structure in which a pattern and an insulating film are sequentially formed on the substrate. The cleaning apparatus as claimed in claim 4, wherein the heating is performed by E-beam or electric resistance heat.








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