KR20100122367A - Optic liquid crystal lens not including an alignment layer and method of manufacturing the same - Google Patents

Abstract

PURPOSE: An optical liquid crystal lens without an alignment layer and a manufacturing method thereof are provided to freely control a focus distance and reduce thickness of a mobile device. CONSTITUTION: A first substrate(200) is separated from a second substrate(202). A liquid crystal layer(208) is aligned between the first and second substrates and is made of liquid polymers. At least one substrate is made of polydimethysiloxane.

Description

Optical liquid crystal lens implemented without an alignment layer and a method for manufacturing the same {OPTIC LIQUID CRYSTAL LENS NOT INCLUDING AN ALIGNMENT LAYER AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an optical liquid crystal lens and a method of manufacturing the same, and more particularly, to an optical liquid crystal lens capable of arranging liquid crystal molecules in a predetermined direction through an alignment treatment without an alignment layer and a method of manufacturing the same.

Unlike general cameras, cameras mounted on small mobile devices, such as a mobile phone, use a small motor to change the focal length of the lens when the optical zoom is driven. However, since the motor is used, a space for implementing the motor must be secured, and as a result, integration is not easy.

Therefore, in view of integration, a digital zoom method without an optical zoom function has emerged. However, since the digital zoom method analyzes the screen inputted to the sensor in a circuit, the resolution of the camera decreases due to the enlargement of the screen.

In order to overcome this disadvantage, a thin film lens and a voltage driven optical liquid crystal lens have emerged.

The thin film lens adjusts the focal length of the lens by controlling the flow rate of the liquid through a micro actuator, but it is difficult to miniaturize the small mobile device because an additional drive system for controlling the liquid is required.

The voltage driven optical liquid crystal lens uses a method of controlling a focal length by adjusting a driving voltage, and generally has a structure shown in FIG. 1 below.

1 is a cross-sectional view showing a general voltage-driven optical liquid crystal lens.

Referring to FIG. 1, the optical liquid crystal lens includes a first glass substrate 100, a second glass substrate 102, a first electrode 104, a second electrode 106, a first alignment layer 108, and a second alignment layer. 110, a liquid crystal layer 112, and spacers 114.

The first electrode 104 is formed on one surface of the first glass substrate 100, and the second electrode 106 is formed on one surface of the second glass substrate 102. Here, when different voltages are applied to the electrodes 104 and 106, an electric field is generated between the electrodes 104 and 106 to arrange the liquid crystal molecules of the liquid crystal layer 112 in a predetermined direction, and as a result, a constant focal length. Is implemented.

As illustrated in FIG. 1, the first alignment layer 108 is formed on one surface of the first glass substrate 100, and the second alignment layer 110 is formed on one surface of the second glass substrate 102.

Liquid crystal molecules of the liquid crystal layer 112 are positioned between the alignment layers 108 and 110, and the liquid crystal molecules may be arranged in a predetermined direction by the alignment layers 108 and 110.

The spacers 114 maintain a constant gap between the first glass substrate 100 and the second glass substrate 102 and prevent the liquid crystal molecules of the liquid crystal layer 112 from leaking to the outside. .

That is, the optical liquid crystal lens controls the focal length by arranging liquid crystal molecules of the liquid crystal layer 112 in a predetermined direction by applying a predetermined voltage to the electrodes 104 and 106.

Such an optical liquid crystal lens can reduce the thickness of the camera as compared to an optical zoom lens, thereby miniaturizing a mobile device. However, as the mobile device becomes more compact, development of an optical liquid crystal lens having a smaller thickness is required.

An object of the present invention is to provide an optical liquid crystal lens capable of freely controlling the focal length while reducing the thickness of the mobile device or the like and a method of manufacturing the same.

In order to achieve the above object, an optical liquid crystal lens according to an embodiment of the present invention comprises a first substrate; A second substrate arranged to be spaced apart from the first substrate by a predetermined distance; And a liquid crystal layer arranged between the first substrate and the second substrate and composed of liquid crystal molecules. Here, at least one of the substrates consists of polydimethylsiloxane (PDMS).

An optical liquid crystal lens according to another embodiment of the present invention includes a first substrate; A second substrate arranged to be spaced apart from the first substrate by a predetermined distance; And a liquid crystal layer arranged between the first substrate and the second substrate and composed of liquid crystal molecules. Here, the surface of at least one of the substrates is aligned by ion beam alignment, and the liquid crystal molecules of the liquid crystal layer are arranged in a specific direction in accordance with the patterning process.

An optical liquid crystal lens manufacturing method according to an embodiment of the present invention comprises the steps of aligning the first substrate made of PDMS through the ion beam alignment method; Orienting the second substrate made of PDMS through an ion beam alignment method; Forming a first electrode on one surface of the first substrate; Forming a second electrode on one surface of the second substrate; And forming a liquid crystal layer made of liquid crystal molecules between the substrates on which the electrodes are formed.

In the optical liquid crystal lens and the method of manufacturing the same according to the present invention, the substrates made of PDMS are aligned by ion beam alignment, and as a result, the liquid crystal molecules of the liquid crystal layer may be arranged in a predetermined direction without the alignment layer. Therefore, there is an advantage that the thickness of the camera and the mobile device using the optical liquid crystal lens can be reduced.

In addition, since it is not necessary to perform the process of forming the alignment layer as in the prior art, the manufacturing time of the lens can be reduced by reducing the step of manufacturing the optical liquid crystal lens.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination 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. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view showing an optical liquid crystal lens according to a first embodiment of the present invention.

The optical liquid crystal lens of this embodiment is a voltage-driven liquid crystal lens whose focal length can be varied according to the applied voltage, and can be used in a small mobile device such as a portable camera.

Referring to FIG. 2, the optical liquid crystal lens of the present embodiment includes a first substrate 200, a second substrate 202, a first electrode 204, a second electrode 206, a liquid crystal layer 208, and spacers. 210).

The first substrate 200 and the second substrate 202 are each made of a transparent material so that an image of a subject to be photographed can pass therethrough.

According to one embodiment of the invention, at least one of the substrates 200 and 202 consists of polydimethylsiloxane (PDMS), preferably both of PDMS.

The first electrode 204 is formed on one surface of the first substrate 200, and the second electrode 206 is formed on one surface of the second substrate 202. Here, each of the electrodes 204 and 206 is made of a transparent conductor material such as ITO, Al, AZO, Au, or the like.

According to an embodiment of the present invention, the second electrode 206 may be formed of two sub electrodes separated from each other as shown in FIG. 2.

In the optical liquid crystal lens of this structure, when different voltages are applied to the electrodes 204 and 206, an electric field is generated between the first electrode 204 and the second electrode 206. Here, since the sub-electrodes of the second electrode 206 are separated from each other, the intensity of the electric field varies depending on the position of the optical liquid crystal lens. In this case, the liquid crystal molecules of the liquid crystal layer 208 are arranged in a specific direction according to the intensity of the electric field, that is, a constant focal length sphere is implemented.

As shown in FIG. 2, the liquid crystal layer 208 is positioned between the first substrate 200 and the second substrate 202, and is formed of liquid crystal molecules including liquid crystals. Here, the optical liquid crystal lens of the present embodiment varies the focal length through the change of the arrangement of the liquid crystal molecules. Specifically, the focal length of the optical liquid crystal lens can be changed by varying the magnitude of voltages applied to the electrodes 204 and 206 to vary the arrangement of liquid crystal molecules in the liquid crystal layer 208.

The spacers 210 are positioned between the first substrate 200 and the second substrate 202 to maintain a constant gap between the substrates 200 and 202 and the liquid crystal molecules of the liquid crystal layer 208 flow out to the outside. It prevents it from becoming a problem.

According to an embodiment of the present invention, the spacers 210 may also be made of transparent PDMS.

In short, the optical liquid crystal lens of this embodiment uses a voltage driving method to vary the focal length. In particular, each of the substrates 200 and 202 may be made of a transparent PDMS. As a result, the liquid crystal molecules of the liquid crystal layer 208 without the alignment layer may be aligned in a predetermined direction by performing alignment treatment on the substrates 200 and 202 as described below. Can be arranged.

That is, unlike the conventional optical liquid crystal lens in which the alignment film is essentially required, the liquid crystal molecules may be arranged in a predetermined direction even if the alignment film does not exist in the optical liquid crystal lens of the present embodiment. Therefore, the thickness of the optical liquid crystal lens of this embodiment can be smaller than that of the conventional optical liquid crystal lens, and as a result, the thickness of the camera using the optical liquid crystal lens of this embodiment can also be reduced.

Although not shown in FIG. 2, the optical liquid crystal lens of the present exemplary embodiment may further include a third electrode capable of finely adjusting an electric field in addition to the first electrode 204 and the second electrode 206. The third electrode may be implemented in various ways, such as between the liquid crystal layer 208 and the second substrate 202.

Hereinafter, a method of manufacturing the optical liquid crystal lens of the present invention will be described with reference to the accompanying drawings.

3 is a cross-sectional view illustrating a process of manufacturing an optical liquid crystal lens according to an embodiment of the present invention.

Referring to FIG. 3A, ion beams are irradiated onto surfaces of the first substrate 200 and the second substrate 202, respectively. That is, the surface of each of the substrates 200 and 202 is oriented through the ion beam alignment method.

Specifically, when each of the substrates 200 and 202 is made of PDMS, the surface of the substrates 200 and 202 is broken while covalent bonds or π bonds are broken among the bonds forming the PDMS by the ion beam alignment method. Anisotropy of is increased. As a result, the liquid crystal molecules of the liquid crystal layer 208 may be arranged in a predetermined direction according to the alignment process. That is, unlike in the conventional optical liquid crystal lens in which the alignment film was essentially required, in the optical liquid crystal lens of the present embodiment, the liquid crystal molecules of the liquid crystal layer 208 without the alignment film are aligned in a predetermined direction by performing alignment treatment on the substrates 200 and 202. Can be arranged. In other words, the substrates 200 and 202 of the present embodiment serve not only as the substrate but also as the alignment layer.

Referring to FIG. 3B, a first electrode 204 is formed on one surface of the alignment-oriented first substrate 200, and a second electrode 206 is formed on one surface of the alignment-oriented second substrate 202. Is formed.

Referring to FIG. 3C, spacers 210 are formed on, for example, an adhesive or the like on the first substrate 200 on which the first electrode 204 is formed. Here, the spacers 210 may be made of PDMS in consideration of transparency.

Referring to FIG. 3D, liquid crystal molecules made of liquid crystals are injected between the substrates 200 and 202, that is, a liquid crystal layer 208 is formed between the substrates 200 and 202. Here, the liquid crystal molecules of the liquid crystal layer 208 are not leaked out by the spacers 210.

Referring to FIG. 3E, the second substrate 202 and the spacers 210 are coupled through an adhesive, for example, and finally, the manufacture of the optical liquid crystal lens is completed.

In short, the optical liquid crystal lens manufacturing method of the present embodiment aligns the substrates 200 and 202 made of PDMS by ion beam alignment to arrange liquid crystal molecules of the liquid crystal layer 208 in a constant direction. Therefore, the optical liquid crystal lens manufacturing step can be reduced as compared with the conventional technology which essentially included the alignment film forming process, and thus the manufacturing process time can be shortened.

4 is a cross-sectional view illustrating an optical liquid crystal lens according to a second embodiment of the present invention.

Referring to FIG. 4, the optical liquid crystal lens of the present embodiment includes a first substrate 400, a second substrate 402, a first electrode 404, a second electrode 406, and a liquid crystal layer 408.

Since the other components except for the first substrate 400 are the same as in the first embodiment, detailed descriptions of the same components will be omitted.

The first substrate 400 includes a base portion 410 and a spacer portion 412.

The base part 410 is a body of the first substrate 400, and a first electrode 404 is formed under the base part 410.

The spacer portion 412 extends from the base portion 410 in a direction crossing the base portion 410, preferably in a direction perpendicular to the base portion 410.

The spacer portion 412 serves to maintain a gap between the base portion 410 and the second substrate 402.

In other words, in the optical liquid crystal lens of the present embodiment, the first substrate 400 may perform not only the role of the substrate and the alignment layer but also the role of the spacer.

Although not described above, at least one of the substrates 400 and 402 may be made of PDMS, and the surfaces of the substrates 400 and 402 are oriented through ion beam alignment.

5 is a cross-sectional view illustrating an optical liquid crystal lens according to a third exemplary embodiment of the present invention.

Referring to FIG. 5, the optical liquid crystal lens of the present exemplary embodiment includes a first substrate 500, a second substrate 502, a first electrode 504, a second electrode 506, and a liquid crystal layer 508.

Since the components of the present embodiment except for the second substrate 502 are the same as those of the second embodiment, detailed descriptions of the same components will be omitted.

The second substrate 502 may be made of PDMS, and a portion 510 thereof may be convex, as shown in FIG. 5. As a result, the particular portion 510 of the second substrate 502 can serve as a lens that can vary the focal length.

That is, the optical liquid crystal lens of the present exemplary embodiment may not only control the focal length using the liquid crystal layer 508 but also control the focal length by utilizing a portion 510 of the second substrate 502 as a lens.

In general, the camera including the optical liquid crystal lens further includes a plurality of lenses and sensors in addition to the optical liquid crystal lens. That is, since the portion 510 of the second substrate 502 is usable as a lens, the number of lenses and the total length of the lens barrel can be reduced. In detail, the number of refractions of light incident on the optical liquid crystal lens may be increased due to the lens of the second substrate 502, so that the focal length of the image of the photographed subject may be shortened.

In the above, although the first substrate 500 is implemented to serve as a spacer, spacers may be additionally provided as in the first embodiment.

6 is a cross-sectional view illustrating an optical liquid crystal lens according to a fourth embodiment of the present invention.

Referring to FIG. 6, the optical liquid crystal lens of the present exemplary embodiment includes a first substrate 600, a second substrate 602, a first electrode 604, a second electrode 606, and a liquid crystal layer 608.

Since the components of the present embodiment except for the first substrate 600 are the same as those of the third embodiment, detailed descriptions of the same components will be omitted.

The first substrate 600 may be made of PDMS, and as shown in FIG. 6, a portion 610 of the first substrate 600 may be concave to serve as a lens.

The second substrate 602 may be made of PDMS, and a portion 612 thereof may be convex to serve as a lens.

That is, the optical liquid crystal lens of this embodiment not only uses the liquid crystal molecules of the liquid crystal layer 608 as a lens role but also uses the substrates 600 and 602 as a lens.

In the above, although the first substrate 600 is implemented to serve as a spacer, spacers may be additionally provided as in the first embodiment.

The embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention. Should be considered to be within the scope of the following claims.

1 is a cross-sectional view showing a general voltage-driven optical liquid crystal lens.

2 is a cross-sectional view showing an optical liquid crystal lens according to a first embodiment of the present invention.

3 is a cross-sectional view illustrating a process of manufacturing an optical liquid crystal lens according to an embodiment of the present invention.

4 is a cross-sectional view illustrating an optical liquid crystal lens according to a second embodiment of the present invention.

5 is a cross-sectional view illustrating an optical liquid crystal lens according to a third exemplary embodiment of the present invention.

6 is a cross-sectional view illustrating an optical liquid crystal lens according to a fourth embodiment of the present invention.

Claims (12)

A first substrate; A second substrate arranged to be spaced apart from the first substrate by a predetermined distance; And A liquid crystal layer arranged between the first substrate and the second substrate and comprising liquid crystal molecules; At least one of the substrates is made of polydimethylsiloxane (PDMS). The optical liquid crystal lens according to claim 1, wherein the surfaces of the substrates are aligned by ion beam alignment. The optical liquid crystal lens of claim 1, A first electrode formed on one surface of the first substrate; A second electrode formed on one surface of the second substrate; And Spacers for maintaining the spacing of the substrate further comprises And the spacers are made of PDMS. The method of claim 1, wherein the first substrate, A base portion; And Including a spacer portion extending in length from the base portion in a direction crossing the base portion, And the spacer part maintains a constant distance between the base part and the second substrate. 2. The method of claim 1, wherein the portion is concave or convex so that a portion of the first substrate acts as a lens, and the portion is concave or convex so that a portion of the second substrate acts as a lens. Optical liquid crystal lens made with. A first substrate; A second substrate arranged to be spaced apart from the first substrate by a predetermined distance; And A liquid crystal layer arranged between the first substrate and the second substrate and composed of liquid crystal molecules, And at least one surface of the substrates is aligned by ion beam alignment, and the liquid crystal molecules of the liquid crystal layer are arranged in a specific direction according to the patterning process. The method of claim 6, wherein the optical liquid crystal lens, A first electrode formed on one surface of the first substrate; A second electrode formed on one surface of the second substrate; And Spacers for maintaining the spacing of the substrate further comprises And at least one of the first substrate, the second substrate, and the spacers is made of PDMS. The method of claim 6, wherein the first substrate, A base portion; And Including a spacer portion extending in length from the base portion in a direction crossing the base portion, And the spacer part maintains a gap between the base part and the second substrate. The method of claim 6, wherein the portion is concave or convex so that a portion of the first substrate serves as a lens, and the portion is concave or convex so that a portion of the second substrate serves as a lens. An optical liquid crystal lens characterized by. Orienting the first substrate made of PDMS through an ion beam alignment method; Orienting the second substrate made of PDMS through an ion beam alignment method; Forming a first electrode on one surface of the first substrate; Forming a second electrode on one surface of the second substrate; And And forming a liquid crystal layer made of liquid crystal molecules between the substrates on which the electrodes are formed. The method of claim 10, wherein the optical liquid crystal lens manufacturing method, Forming spacers between the substrates before arranging the liquid crystal layer to maintain a constant gap between the substrates, At least one of the spacers is made of PDMS. The method of claim 10, wherein the first substrate, A base portion; And Including a spacer portion extending in length from the base portion in a direction crossing the base portion, And the spacer part maintains a gap between the base part and the second substrate and is made of PDMS.

Images