KR20170119919A - Lens and lens assembly comprising the same - Google Patents

Abstract

A lens according to an embodiment of the present invention includes a substrate, a hydrophilic coating layer formed on the substrate and including a polymer having a hydrophilic functional group, and a hydrophilic coating layer disposed between the substrate and the hydrophilic coating layer, wherein Sn, Ti, W, K, P , Zn and Si, and the inorganic oxide layer has a thickness of 60 nm to 140 nm.

Description

≪ Desc / Clms Page number 1 > LENS AND LENS ASSEMBLY COMPRISING THE SAME

The present invention relates to a lens having a coating layer formed on its surface and a lens assembly including the same.

The lens disposed at the outermost one of the lens assemblies included in the camera module is exposed to the external environment. Particularly, when the camera module is mounted on a vehicle, the optical characteristics of the camera module may deteriorate due to rain, mist, light reflection, dust, or the like, or the visual field may be insufficient.

Accordingly, there is an attempt to hydrophilic coat the lens of the camera module. When the lens surface of the camera module is hydrophilic coated, water droplets on the surface of the lens spread widely, which can solve problems such as scattering of light, frost, fogging, contamination, image bending and the like.

However, when a hydrophilic solution is coated on the surface of the lens, the hydrophilic solution is not easily coated due to the surface resistance of the lens. Further, even if the coating is applied, the bonding force between the lens surface and the hydrophilic coating layer is low, so that the hydrophilic coating layer tends to be worn off or detached, and it is difficult to obtain super-hydrophilic properties.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens and a lens assembly including the same that can stably maintain optical characteristics and field of view even in an external environment such as rain and fog.

 A lens according to an embodiment of the present invention includes a substrate, a hydrophilic coating layer formed on the substrate and including a polymer having a hydrophilic functional group, and a hydrophilic coating layer disposed between the substrate and the hydrophilic coating layer, wherein Sn, Ti, W, K, P , Zn and Si, and the inorganic oxide layer has a thickness of 60 nm to 140 nm.

The inorganic oxide layer may include a plurality of layers.

The inorganic oxide layer may be alternately arranged between a first layer containing a first oxide and a second layer containing a second oxide.

Wherein the first oxide is SiO _2, the second oxide may be TiO _2.

Layer in contact with the hydrophilic coating layer of the plurality of layers may include SiO _2.

The thickness of the inorganic oxide layer may be from 90 nm to 110 nm.

The surface of the inorganic oxide layer can be activated by a plasma treatment.

The plasma treatment may be performed in at least one of an argon and oxygen atmosphere, an ozone vacuum oxygen atmosphere, and a compressed air atmosphere.

The inorganic oxide layer and the hydrophilic coating layer may be covalently bonded.

The inorganic oxide layer and the hydrophilic coating layer may be covalently bonded by oxygen.

The hydrophilic functional group may be selected from the group consisting of a hydroxyl group, an amino group and an epoxy group.

The water contact angle of the hydrophilic coating layer may be between 3 ° and 6 °.

After the abrasion resistance test in which the surface of the lens is struck 1,500 times with a force of 4.9 N, the change amount of the contact angle on the hydrophilic coating layer may be 4 or less.

A lens assembly according to an embodiment of the present invention includes a housing, a lens accommodated in the housing, and a retainer coupled to one end of the housing and supporting the lens, wherein the lens includes a base, A hydrophilic coating layer including a polymer having a hydrophilic functional group and an inorganic oxide layer disposed between the substrate and the hydrophilic coating layer and including an oxide including at least one of Sn, Ti, W, K, P, And the thickness of the inorganic oxide layer is 60 nm to 140 nm.

The lens and the lens assembly according to the embodiment of the present invention have superhydrophilic characteristics, have high abrasion resistance, and can stably secure optical characteristics and field of view even in an external environment such as rain, mist, and the like.

1 shows an exploded view of a lens assembly according to an embodiment of the present invention.
2 is a cross-sectional view of a lens according to an embodiment of the present invention.
FIG. 3 schematically shows a process of forming a hydrophilic coating layer containing a polymer having a hydrophilic functional group on an inorganic oxide layer according to an embodiment of the present invention.
4 is a cross-sectional view of a lens according to another embodiment of the present invention.
5 is a flowchart showing a method of manufacturing a lens according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The components are not limited by these terms. The terms are used for the purpose of distinguishing one component from another. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

1 shows an exploded view of a lens assembly according to an embodiment of the present invention.

1, the lens assembly 100 includes a housing 110, a lens 120 accommodated in the housing 110, and a retainer (not shown) coupled to one end of the housing 110 and supporting the lens 120. [ , 130).

The lens 120 may include a plurality of lenses sequentially arranged from the object side to the image side. Each lens may have a positive refracting power or a negative refracting power, and may have a convex surface, a concave surface, or a meniscus shape. The refracting power and surface shape of the plurality of lenses can be variously combined according to the required focal length or the like.

The lens assembly according to an embodiment of the present invention may be included in a camera module, for example, a camera module for a vehicle. The camera module may include a lens assembly, a filter, an image sensor, and a printed circuit board according to an embodiment of the present invention. For this, though not shown, a filter, an image sensor, and a printed circuit board may be sequentially arranged behind the lens assembly. That is, an image sensor may be mounted on a printed circuit board, and a filter may be formed on the image sensor. Here, the image sensor can be connected to the printed circuit board by a wire. The image sensor may be, for example, a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor) sensor. The filter may be an infrared (IR) filter. The filter can block near-infrared rays, for example, light having a wavelength of 700 nm to 1100 nm, from light incident into the camera module.

On the other hand, of the plurality of lenses, the lens closest to the object side (hereinafter referred to as the outermost lens) is exposed to the outside. When one side of the lens is exposed to an external environment such as rain, fog, etc., the optical characteristics of the camera module may be deteriorated or the visual field may be insufficient.

In general, there is an attempt to form a water repellent coating layer or a hydrophilic coating layer on a substrate of a lens to ensure a clear visual field.

Particularly, when a hydrophilic coating layer is formed on a base material of a lens, water droplets spread on the lens, thereby preventing fogging or water condensation on the surface of the lens. However, since the bonding force between the substrate of the lens and the hydrophilic coating layer is low, the hydrophilic coating layer formed on the substrate of the lens is likely to be worn. The covalent bonding between the glass and the hydrophilic coating layer is low even when the substrate of the lens is made of glass, which results in a problem that the durability of the hydrophilic coating layer deteriorates.

In the embodiment of the present invention, an inorganic oxide layer is formed between the hydrophilic coating layer and the base material of the lens to increase the bonding force between the hydrophilic coating layer and the substrate of the lens and to increase the abrasion resistance.

2 is a cross-sectional view of a lens according to an embodiment of the present invention.

2, the lens 120 includes a substrate 121, a hydrophilic coating layer 123 formed on the substrate 121, and an inorganic oxide layer 122 disposed between the substrate 121 and the hydrophilic coating layer 123 ).

Here, the hydrophilic coating layer 123 may be formed of a hydrophilic coating liquid, and the hydrophilic coating liquid may include a polymer having a hydrophilic functional group, a nonionic surfactant, and a solvent. The solvent may be water or alcohol-based.

Here, the hydrophilic functional group may be selected from the group consisting of a hydroxyl group, an amino group and an epoxy group. As such, when the hydrophilic coating layer 123 includes a polymer having hydrophilic functional groups, the surface of the lens 120 may have wettability or hydrophilicity. In particular, the surface of the lens 120 according to embodiments of the present invention may have a water contact angle of 10 degrees or less, preferably 5 degrees or less. Here, the water contact angle means an angle formed between the water droplet and the base material interface and the horizontal plane of the base material when water is dropped on the base material. As described above, when the surface of the lens 120 has a super-hydrophilic property, a clear view can be secured even in an environment of rain, mist, and the like.

On the other hand, the inorganic oxide layer 122 disposed on the substrate 121 may contain any one of Sn, Ti, W, K, P, Zn, and Si.

The inorganic oxide layer 122 may be formed on a substrate (not shown) by a method such as spraying, spin coating, dipping, chemical vapor deposition (CVD), or physical vapor deposition 121).

FIG. 3 schematically shows a process of forming a hydrophilic coating layer containing a polymer having a hydrophilic functional group on an inorganic oxide layer according to an embodiment of the present invention.

Referring to FIG. 3, the surface of the inorganic oxide layer 122 is cleaned and then activated. A plasma treatment, an alkyl halide treatment, or an acid base treatment may be performed to activate the surface of the inorganic oxide layer 122. When the inorganic oxide layer 122 is subjected to a plasma treatment, a halogenated alkyl treatment, or an acid base treatment, the hydroxyl group (-OH) is activated on the surface of the inorganic oxide layer 122. Here, the plasma treatment may be performed at atmospheric pressure or vacuum conditions. For example, the plasma treatment may be performed in at least one of an argon and oxygen atmosphere, a vacuum oxygen atmosphere, and a compressed air atmosphere.

Thereafter, a hydrophilic coating solution containing a polymer having a hydrophilic functional group (-R), a nonionic surfactant and a solvent is added on the surface of the inorganic oxide layer 122. Here, the hydrophilic functional group may be selected from the group consisting of, for example, a hydroxyl group, an amino group and an epoxy group. The polymer may further have Si and a hydroxyl group (-OH). Accordingly, the hydroxyl group activated on the surface of the inorganic oxide layer 122 and the hydroxyl group contained in the polymer may react with each other and the inorganic oxide layer 122 and the polymer may be covalently bonded. When the hydrophilic coating layer 123 is formed on the inorganic oxide layer 122 as in the embodiment of the present invention, compared with the case where the hydrophilic coating layer 123 is directly formed on the substrate 121, The bonding force of the hydrophilic coating layer 123 can be increased. Here, the polymer having a hydrophilic functional group may be a polymeric hydrocarbon derivative having a hydrophilic functional group, and the molecular weight of the polymer may be 70,000 to 120,000.

According to an embodiment of the present invention, the thickness of the inorganic oxide layer 122 may be 60 to 140 nm, preferably 90 to 110 nm. When the thickness of the inorganic oxide layer 122 is within the above numerical range, the degree of covalent bonding between the inorganic oxide layer 122 and the hydrophilic coating layer 123 is high, so that the wear resistance of the hydrophilic coating layer 123 can be enhanced. Particularly, if the thickness of the inorganic oxide layer 122 is less than 60 nm, the bonding force between the hydrophilic coating layer 123 and the inorganic oxide layer 122 may be low because the number of active oxygen bonds with the hydrophilic coating layer 123 is small. have. If the thickness of the inorganic oxide layer 122 exceeds 140 nm, there is a high possibility that the inorganic oxide layer 122 itself is separated from the substrate 121.

4 is a cross-sectional view of a lens according to another embodiment of the present invention. 2 to 3 will not be described.

4, a lens 120 according to another embodiment of the present invention includes a substrate 121, a hydrophilic coating layer 123 formed on the substrate 121, and a hydrophilic coating layer 123 between the substrate 121 and the hydrophilic coating layer 123 (Not shown).

Here, the inorganic oxide layer 122 may include a plurality of layers. The plurality of layers may be different kinds of layers or layers of the same kind. In other words, the inorganic oxide layer 122 may be alternately disposed between the first layer containing the first oxide and the second layer containing the second oxide. At this time, the first oxide and the second oxide may all be SiO ₂ . Alternatively, the first and the oxide is SiO _2, the second oxide may be TiO _2.

When the inorganic oxide layer 122 includes a plurality of layers, the possibility that the entire inorganic oxide layer 122 is separated from the substrate 121 is reduced, and the wear resistance is increased. Further, if the inorganic oxide layer 122 includes a plurality of thin film layers, the uniformity of the surface of the lens is increased, so that the defect rate can be lowered. In addition, when the inorganic oxide layer 122 includes a plurality of layers including SiO ₂ and a plurality of layers including TiO ₂ , the reflectivity of the lens 120 can be lowered.

At this time, the layer in contact with the hydrophilic coating layer 123 among the plurality of layers of the inorganic oxide layer 122 may be a layer containing SiO ₂ . Accordingly, the bonding force between the inorganic oxide layer 122 and the hydrophilic coating layer 123 can be increased.

5 is a flowchart showing a method of manufacturing a lens according to an embodiment of the present invention.

Referring to FIG. 5, the substrate 121 is cleaned (S100), and then the inorganic oxide layer 122 is coated on the surface of the substrate 121 (S120). At this time, the inorganic oxide layer 122 may include any one of Sn, Ti, W, K, P, Zn, and Si, and may be formed by spraying, spin coating, dipping, May be formed on the substrate 121 by a method such as chemical vapor deposition (CVD), physical vapor deposition (PVD), or the like.

Then, the surface of the inorganic oxide layer 122 is cleaned and subjected to a plasma treatment (S120). The plasma treatment may be performed at atmospheric pressure or vacuum conditions. For example, the plasma treatment may be performed in at least one of an argon and oxygen atmosphere, a vacuum oxygen atmosphere, and a compressed air atmosphere.

Then, a hydrophilic coating solution is applied on the surface of the inorganic oxide layer 122 activated by the plasma treatment to perform hydrophilic coating (S130). Here, the hydrophilic coating liquid may include a polymer having a hydrophilic functional group, a nonionic surfactant, and a solvent. Here, the hydrophilic functional group may be selected from the group consisting of a hydroxyl group, an amino group and an epoxy group, and the polymer may include Si and a hydroxyl group. The hydroxyl group contained in the polymer may be covalently bonded to the activated hydroxyl group on the inorganic oxide layer.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The water contact angle test of the lens surface, the transmittance test, and the water contact angle test of the lens surface after the abrasion resistance test were performed.

Table 1 shows the water contact angle test, the transmittance test, the water contact angle test after the abrasion resistance test, and the water contact angle variation of the lens surface according to the comparative example and the examples 1 to 9.

In the comparative example, a hydrophilic coating layer was directly formed on a glass substrate. In the examples, an inorganic oxide layer was formed on a glass substrate, and then a hydrophilic coating layer was formed on the inorganic oxide layer. In Examples 1 to 9, the thickness of the inorganic oxide layer was differently applied, and the inorganic oxide layer included SiO ₂ .

Here, the hydrophilic coating layer was formed of a hydrophilic coating liquid, and the hydrophilic coating liquid contained 2 wt% of a silicone polymer containing a hydroxyl group as a hydrophilic functional group, 15 wt% of a nonionic surfactant, and 83 wt% of water.

The water contact angle was measured with a contact angle measuring instrument (Kruss DSA100) after water was sprayed on the surface of the lens. Here, the water contact angle means an angle formed by the horizontal plane of the lens, the water droplet, and the interface between the lens surface and the surface. The lower the water contact angle, the better the hydrophilic property. The water contact angle was measured by dividing the initial water contact angle measured after the hydrophilic coating and the water contact angle measured after the abrasion resistance test.

The transmittance of the lens was measured before the abrasion resistance test using a spectrophotometer.

The abrasion resistance test was carried out using a canvas cloth having a thickness of 20 mm and a width of 20 mm so as to hit the surface of the lens with a force of 4.9 N so as to reach an area of 100 5 mm ² with a canvas cloth. The initial contact angle of water on the lens surface and the water contact angle of the lens surface after abrasion resistance test were used to confirm the change in the water contact angle.

division Comparative Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 SiO ₂ thickness [nm] 0 40 60 80 90 100 110 120 140 200 Initial contact angle
[°] 4 to 7 8-12 6 to 10 6 to 9 3 to 6 3 to 6 3 to 6 3 to 6 3 to 6 3 to 6 Transmittance
[%] 95 94 93 92 92 92 92 90 90 87 Contact angle after wear test [°] 30 to 50 17 ~ 21 9 ~ 15 8-12 6 to 7 6 to 7 6 to 7 9-11 9-13 15 ~ 21 Contact angle
Change [°] 26 to 46 7 to 13 3 ~ 9 2 to 6 3 to 4 3 to 4 3 to 4 6 to 8 6 to 10 12-18

According to Table 1, when the hydrophilic coating layer was formed directly on the substrate as in the comparative example, the difference between the water contact angle before the abrasion resistance test and the water contact angle after the abrasion resistance test was 26 to 46 °, In the case where the inorganic precondensable layer is included between the coating layers, the difference between the water contact angle before the abrasion resistance test and the water contact angle after the abrasion resistance test is 2 to 18 degrees. That is, according to the embodiment of the present invention, when the inorganic oxide layer is included between the substrate and the hydrophilic coating layer, the wear resistance of the hydrophilic coating layer is increased.

Particularly, when the thickness of the SiO ₂ layer is formed in the range of 60 nm to 140 nm as in Examples 2 to 8, the water contact angle after the abrasion resistance test is measured in the range of 6 ° to 13 °, and the water contact angle before the abrasion resistance test and the water contact angle after the abrasion resistance test The difference between them was measured up to 10 °. When the thickness of the SiO ₂ layer was formed in the range of 90 to 110 nm as in Examples 4 to 6, the initial contact angle of water repellency was measured at 3 to 6 degrees, and the contact angle of water after the abrasion resistance test was 6 to 7 °, and the difference between the water contact angle before and after the abrasion resistance test was measured to be 3 ° to 4 °, that is, 4 ° maximum.

As described above, when the thickness ranges of Examples 2 to 8, and preferably the thickness ranges of Examples 4 to 6, are satisfied, it is found that they have excellent abrasion resistance properties.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

100: lens assembly
110: Housing
120: lens
130: retainer
121: substrate
122: inorganic oxide layer
123: hydrophilic coating layer

Claims (14)

materials,
A hydrophilic coating layer formed on the substrate and including a polymer having a hydrophilic functional group, and
An inorganic oxide layer disposed between the substrate and the hydrophilic coating layer and including an oxide including at least one of Sn, Ti, W, K, P, Zn and Si;
/ RTI >
Wherein the inorganic oxide layer has a thickness of 60 nm to 140 nm. The method according to claim 1,
Wherein the inorganic oxide layer comprises a plurality of layers. 3. The method of claim 2,
Wherein the inorganic oxide layer is disposed such that a first layer containing a first oxide and a second layer containing a second oxide are alternately arranged. The method of claim 3,
Wherein the first oxide is SiO _2, the second oxide is TiO ₂ in the lens. 3. The method of claim 2,
Among the plurality of lens layer to layer in contact with the hydrophilic coating layer comprises SiO _2. The method according to claim 1,
Wherein the thickness of the inorganic oxide layer is from 90 nm to 110 nm. The method according to claim 1,
Wherein the surface of the inorganic oxide layer is activated by a plasma treatment. 8. The method of claim 7,
Wherein the plasma treatment is performed in at least one of an argon and oxygen atmosphere, an ozone vacuum oxygen atmosphere, and a compressed air atmosphere. The method according to claim 1,
Wherein the inorganic oxide layer and the hydrophilic coating layer are covalently bonded. 10. The method of claim 9,
Wherein the inorganic oxide layer and the hydrophilic coating layer are covalently bonded by oxygen. The method according to claim 1,
Wherein the hydrophilic functional group is selected from the group consisting of a hydroxyl group, an amino group and an epoxy group. The method according to claim 1,
Wherein the hydrophilic coating layer has a water contact angle of 3 DEG to 6 DEG. The method according to claim 1,
Wherein the contact angle change amount on the hydrophilic coating layer after the abrasion resistance test in which the surface of the lens is struck 1,500 times with a force of 4.9 N is 4 DEG or less. housing,
A lens housed in the housing, and
And a retainer that is coupled to one end of the housing and supports the lens,
The lens,
materials,
A hydrophilic coating layer formed on the substrate and including a polymer having a hydrophilic functional group, and
And an inorganic oxide layer disposed between the substrate and the hydrophilic coating layer and including an oxide including at least one of Sn, Ti, W, K, P, Zn and Si,
Wherein the inorganic oxide layer has a thickness of 60 nm to 140 nm.

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