Reflective active variable lens and method of fabricating the same

A reflective active variable lens includes an upper electrode, a lower electrode disposed in parallel to the upper electrode, a deformation part disposed between the upper electrode and the lower electrode, a reflective part disposed on the upper electrode, and a support part disposed to surround the deformation part. Here, the deformation part and the support part are connected to each other to provide a single structure, the deformation part is expanded from an initial shape when an electric field is formed between the upper electrode and the lower electrode, and the expanded deformation part is contracted when the electric field is removed and restored to the initial shape.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application Nos. 10-2017-0180012, filed on Dec. 26, 2017, and 10-2018-0069223, filed on Jun. 15, 2018, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure herein relates to a reflective active variable lens and a method of fabricating the same.

In recent years, as display technologies on the basis of digital technologies for a camera, a mobile terminal, a projector, and a television has developed, high definition screens and miniaturization on related optical systems are demanded. Also, as miniaturization and convenience of optical lens systems are emphasized to acquire a high-definition image, researches for miniaturization and convenience have been actively processed.

In particular, as a high-definition image sensor is mounted to a camera module that is mounted to the mobile terminal, importance of miniaturization and functions such as a variable focal point and optical zoom have been further emphasized. In general, an actuator is used in a current mobile phone camera module to realize a variable focal point and an optical zoom function. An automatic zoom actuator serves to automatically adjust a focal point by adjusting a position of a lens. The automatic zoom actuator generally uses a voice coil motor (VCM) method and a piezo-method. The VCM method is a driving method using a current flowing through a coil and an electromagnetic force generated by a magnet. The VCM method is limited in electromagnetic wave generation and degree of precision. The piezo-method is a driving method using friction between stator and rotator. The piezo-method has a short life time due to friction and expensive costs. Also, a step motor is generally used for a method of performing an optical zoom function. This method has a limitation in terms of complex mechanism and friction and noise of a gear part because a rotating driving unit rotates a lead screw to move a movable part in a linear manner. As described above, most of typical technologies are difficult in manufacturing with low costs due to a complex structure and have a limitation in miniaturization.

In general, a typical technology of a reflective focus variable lens uses a gas or fluid pressure or an electromagnetic force. A technology using a gas or fluid pressure is difficult in miniaturization or arraying because an additional pressure regulator is necessary, and expensive in manufacturing costs because a manufacturing process and a structure are complex.

SUMMARY

The present disclosure provides a reflective active variable lens that is improved in performance.

The present disclosure also provides a method of fabricating a reflective active variable lens that is improved in process efficiency.

However, the effects of the embodiments of the inventive concept are not limited to the above description.

An embodiment of the inventive concept provides a reflective active variable lens including: an upper electrode; a lower electrode disposed in parallel to the upper electrode; a deformation part disposed between the upper electrode and the lower electrode; a reflective part disposed on the upper electrode; and a support part disposed to surround the deformation part. Here, the deformation part and the support part are connected to each other to provide a single structure, the deformation part is expanded from an initial shape when an electric field is formed between the upper electrode and the lower electrode, and the expanded deformation part is contracted when the electric field is removed and restored to the initial shape.

In exemplary embodiments, the support part may have a ring shape extending along an edge of the deformation part.

In exemplary embodiments, the support part may protrude from a bottom surface of the deformation part in a direction perpendicular to the bottom surface.

In exemplary embodiments, the reflective active variable lens may further include: a lower support trench provided at a lower portion of the support part; and an additional support part provided in the lower support trench. Here, the lower support trench may include a region in which a bottom surface of the support part is recessed, and the additional support part may have a ring shape extending in an extension direction of the support part.

In exemplary embodiments, the reflective active variable lens may further include a central hole configured to expose an inner surface of the support part and a bottom surface of the lower electrode.

In exemplary embodiments, the central hole may have a uniform diameter.

In exemplary embodiments, the central hole may have a diameter that gradually increases in a direction away from the deformation part.

In exemplary embodiments, the inner surface of the support part may have a recessed shape.

In exemplary embodiments, the lower electrode may extend along the inner surface of the support part to a bottom surface of the support part.

In exemplary embodiments, the upper electrode and the reflective part may be connected to each other to form an upper reflective electrode.

In exemplary embodiments, the reflective active variable lens may further include an upper support trench defined in an upper portion of the support part. Here, the upper support trench may include a region in which a top surface of the support part is recessed and extend along an extension direction of the support part.

In exemplary embodiments, the reflective active variable lens may further include a packaging structure extending along an edge of the support part to cover an area disposed adjacent to the edge.

In exemplary embodiments, the packaging structure may include a protruding portion that fills the upper support trench.

In exemplary embodiments of the inventive concept, a method of fabricating a reflective active variable lens includes: forming a deformation part, a support part disposed to surround the deformation part, and a body part including a central hole configured to expose a bottom surface of the deformation part and an inner surface of the support part; forming an upper electrode and a reflective part on a top surface of the deformation part in an order; and forming a lower electrode in the central hole. Here, the support part has a ring shape extending along an edge of the deformation part, the lower electrode is disposed on a bottom surface of the deformation part, and the upper electrode and the lower electrode overlap each other in a direction perpendicular to the top surface of the deformation part.

In exemplary embodiments, the forming of the body part may include: providing a liquefied polymer material on a mold structure; hardening the liquefied polymer material; and removing the mold structure.

In exemplary embodiments, the upper electrode may extend from the top surface of the deformation part to a top surface of the support part.

In exemplary embodiments, the method may further include an additional support part disposed at a lower portion of the support part. Here, the additional support part may have a ring shape extending along an extension direction of the support part.

In exemplary embodiments, the forming of the additional support part may include: forming a lower support trench having a shape in which a bottom surface of the support part is recessed at the lower portion of the support part; and inserting the additional support part into the lower support trench.

DETAILED DESCRIPTION

Exemplary embodiments of technical ideas of the inventive concept will be described with reference to the accompanying drawings so as to sufficiently understand constitutions and effects of the inventive concept. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Further, the present invention is only defined by scopes of claims.

Like reference numerals refer to like elements throughout. The embodiment in the detailed description will be described with cross-sectional views and/or plan views as ideal exemplary views of the inventive concept. In the figures, the dimensions of regions are exaggerated for effective description of the technical contents. Areas exemplified in the drawings have general properties, and are used to illustrate a specific shape of a semiconductor package region. Thus, this should not be construed as limited to the scope of the present invention. It will be understood that although the terms first and second are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one component from another component. Embodiments described and exemplified herein include complementary embodiments thereof.

In the following description, the technical terms are used only for explaining a specific exemplary embodiment while not limiting the inventive concept. In this specification, the terms of a singular form may include plural forms unless specifically mentioned. The meaning of “include,” “comprise,” “including,” or “comprising,” specifies a property, a region, a fixed number, a step, a process, an element and/or a component but does not exclude other properties, regions, fixed numbers, steps, processes, elements and/or components.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the invention with reference to the attached drawings.

FIG. 1is a planar perspective view illustrating a reflective active variable lens according to an embodiment of the inventive concept.FIG. 2is a perspective view illustrating a bottom surface of the reflective active variable lens inFIG. 1.FIG. 3is an exploded perspective view illustrating the reflective active variable lens inFIG. 2.FIG. 4is a cross-sectional view taken along line I-I′ inFIG. 1.

Referring toFIGS. 1 to 4, a reflective active variable lens10may include a body part1, an upper electrode210, a lower electrode220, and a reflective part300. The body part1may include a deformation portion110and a support part120. The deformation part110may be deformed by an electric field passing therethrough. When an electric field is applied to the deformation part110, the deformation part110may be expanded in a perpendicular direction to the electric field from an initial state. When the electric field is removed from the deformation part110, the expanded deformation part110may be contracted and restored to the initial state. For example, the deformation part110may include an electro active polymer (EAP).

The upper electrode210and the lower electrode220may be disposed at opposite sides to each other with the deformation part110therebetween. The upper and lower electrodes210and220may be provided on a top surface110uand a bottom surface110bof the deformation part110, respectively. The upper electrode210, the deformation part110, and the lower electrode220may overlap in a direction perpendicular to the top surface110uof the deformation part110. The upper electrode210and the lower electrode220may directly contact the deformation part110. The upper electrode210and the lower electrode220may be parallel to each other. The lower electrode220may be exposed by a central hole CH defined in a lower portion of the body part1. The upper electrode210and the lower electrode220may include a conductive material having flexibility. For example, the upper electrode210and the lower electrode220may include at least one of a silver nano-wire, a graphene, a carbon nano-tube, metal having flexibility, and a conductive polymer having flexibility.

The upper electrode210and the lower electrode220may be applied by different voltages from each other. Accordingly, an electric field may be formed between the upper electrode210and the lower electrode220. The electric field may pas through the deformation part110to expand the deformation part110.

The reflective part300may be provided on the upper electrode210. The reflective part300may overlap in the direction perpendicular to the top surface110uof the deformation part110and the upper electrode210. The reflective part300may directly contact a top surface of the upper electrode210. The reflective part300may be flexible. Accordingly, when the deformation part110is bent, the upper electrode210may be deformed together. The reflective part300may reflect light incident into the reflective part300. For example, the reflective part300may include metal or a dielectric substance. For example, the reflective part300may include gold (Au).

The support part120may surround the deformation part110. The support part120may have a ring shape extending along an end of the deformation part110. The support part120may have a ring shape extending along an edge of the deformation part110. As the support part120is connected to the deformation part110, a single structure may be provided. That is, the support part120and the deformation part110may be connected to each other without a boundary. The support part120may restrict a horizontal size of the deformation part110. The horizontal size of the deformation part110may be a size of the deformation part110in a direction parallel to the top surface120uof the support part120. When the deformation part110is expanded by the electric field passing therethrough, the deformation part110may not be horizontally expanded by the support part120and may be bent in a direction perpendicular to the top surface120uof the support part120. The support part120may include the substantially same material as the deformation part110. For example, the support part120may include an electro active polymer (EAP).

The support part120may have a thickness greater than that of the deformation part110. The thickness of the support part120may be a size of the support part120in the direction perpendicular to the top surface120uof the support part120. The thickness of the deformation part110may be a size of the deformation part110according to the top surface110uof the deformation part110. The top surface120uof the support part120forms a coplanar surface with the top surface110uof the deformation part110. The support part120may protrude from a bottom surface120bof the deformation part110.

The support part120may have an internal diameter122d. The internal diameter122dof the support part120may be a diameter of an inner surface122of the support part120. The inner surface122of the support part120may be exposed by the central hole CH defined in the lower portion of the body part1. The internal diameter122dof the support part120may be constant. For example, the internal diameter122dof the support part120may be constant between the bottom surface110bof the deformation part110and the bottom surface120bof the support part120. The inner surface122of the support part120may extend in the direction perpendicular to the top surface120uof the support part120. That is, the central hole CH may extend in the direction perpendicular to the top surface120uof the support part120while having a predetermined sized diameter.

In general, when the deformation part and the support part are structures independent to each other (i.e., when a boundary surface exists between the deformation part and the support part), the deformation part may not be deformed to have the required shape. For example, the deformation part may be asymmetrically bent.

According to an embodiment of the inventive concept, the deformation part110and the support part120may be connected to each other to form a single structure. Accordingly, the deformation part110may be controlled to have the required shape. For example, the deformation part110may be bent to have a symmetric shape.

The reflective part300may be provided on the deformation part110and deformed in correspondence to the deformation of the deformation part110. As the shape of the deformation part110is adjusted, the reflective part300may be controlled to have the required shape. As a result, the reflective active variable lens10may have a focal position that is actively adjusted by the deformation of the reflective part300.

FIGS. 5 and 6are cross-sectional views taken along line I-I′ inFIG. 1for explaining an operation of the reflective active variable lens according to an embodiment of the inventive concept. For concise description, the substantially same contents as those described with reference toFIGS. 1 to 4will not be described.

Referring toFIG. 5, a voltage may not be applied to the upper electrode210and the lower electrode220. Each of the deformation part110and the reflective part300may extend in a direction parallel to the top surface120uof the support part120. That is, each of the deformation part110and the reflective part300may not be bent. Accordingly, when incident light L1is incident in parallel to an optical axis (not shown) of the reflective active variable lens10, reflected light L2may be reflected in parallel to the optical axis of the reflective active variable lens10.

Referring toFIG. 6, a voltage may be applied to the upper electrode210and the lower electrode220. An electric field (not shown) may be formed in the deformation part110in the direction perpendicular to the top surface110uof the deformation part110. The deformation part110may be expanded in a direction parallel to the top surface110uof the deformation part110by the electric field. Since the horizontal size of the deformation part110is restricted by the support part120, the deformation part110may be bent along the direction perpendicular to the top surface120uof the support part120. The upper electrode210and the reflective part300may be bent in correspondence to the shape of the top surface110uof the deformation part110. Accordingly, when the incident light L1is incident in parallel to an optical axis (not shown) of the reflective active variable lens10, the reflected light L2may be collected to a focal point of the reflective active variable lens10. A degree of deformation of the deformation part110may be adjusted according to a size of the voltage applied to the upper electrode210and the lower electrode220. As a result, as the size of the voltage applied to the upper electrode210and the lower electrode220, the focal point of the reflective active variable lens10may be controlled.

FIG. 7is a bottom perspective view illustrating a reflective active variable lens according to exemplary embodiments of the inventive concept.FIG. 8is an exploded perspective view illustrating the reflective active variable lens inFIG. 7.FIG. 9is a cross-sectional view taken long line I-I′ inFIG. 1. For concise description, the substantially same contents as those described with reference toFIGS. 1 to 4will not be described.

Referring toFIGS. 1 and 7 to 9, a reflective active variable lens20may include a body part2, an upper electrode210, a lower electrode220, a reflective part300, and an additional support part400. The body part2may include a deformation part110and a support part120. The deformation part110, the upper electrode210, the lower electrode220, and the reflective part300may be the substantially same as the deformation part110, the upper electrode210, the lower electrode220, and the reflective part300, which are described with reference toFIGS. 1 to 4. A lower support trench LST may be provided on a lower portion of the support part120. The lower support trench LST may be a region in which the bottom surface120bof the support part120is recessed. The lower support trench LST may be provided between the inner surface122of the support part120and an outside surface (not shown). The lower support trench LST may extend in an extension direction of the support part120. The lower support trench LST may have a ring shape. The lower support trench LST may share a central axis with the support part120.

The additional support part400may be provided in the lower support trench LST. The additional support part400may be inserted to the lower portion of the support part120. The additional support part400may extend along the lower support trench LST. The additional support part400may have a ring shape. The additional support part400may share a central axis with the support part120. The additional support part400may restrict a horizontal size of the deformation part110. The additional support part400may be disposed between the inner surface122and the outside surface of the support part. The additional support part400may have side surfaces and a top surface, which are covered by the support part120. The additional support part400may have a bottom surface (not shown) that is exposed. The bottom surface of the additional support part400may form a coplanar surface with the bottom surface120bof the support part120. The additional support part400may be made of a rigid material. For example, the additional support part400may include acrylic. The additional support part400according to an embodiment of the inventive concept may restrict the horizontal size of the deformation part110. Accordingly, when a voltage is applied to the upper electrode210and the lower electrode220, the deformation part110may be deformed to have the required shape. Accordingly, the reflective part300may be deformed to have the required shape. As a result, the focal point of the reflective active variable lens20may be actively adjusted.

FIG. 10is a flowchart for explaining a method of fabricating another reflective active variable lens according to exemplary embodiments of the inventive concept.FIGS. 11 and 14are cross-sectional views taken along line I-I′ inFIG. 1for explaining the method of fabricating another reflective active variable lens according to exemplary embodiments of the inventive concept.

Referring toFIGS. 10 and 11, a body part2may be formed on a mold structure MS in operation S10. The body part2may include a deformation part110and a support part120. The deformation part110and the support part120may be the substantially same as the deformation part110and the support part120, which are described with reference toFIGS. 7 to 9. The mold structure MS may have a concave-convex structure to form a central hole CH and a lower support trench LST in a lower portion of the body part2. The mold structure MS may be made of a rigid material. For example, the mold structure MS may include metal.

Forming of the body part2may include providing a liquefied polymer material (not shown) on the mold structure MS and hardening the liquefied polymer material. For example, the providing of the liquefied polymer material may include applying a liquefied polymer material on the mold structure MS. The providing of the liquefied polymer material may be performed until when a top surface of the mold structure MS is sunk by the liquefied polymer material. The liquefied polymer material provided on the mold structure MS may have a flat top surface. The hardening of the liquefied polymer material may include curing the liquefied polymer material. For example, the curing of the liquefied polymer material may include heating the liquefied polymer material at a temperature of about 70° C. to 120° C. The body part2may be made of a flexible material. Accordingly, the body part2may be bent or stretched. For example, the body part2may include an electro active polymer (EAP).

Referring toFIGS. 10 and 12, the mold structure MS may be removed from the body part2in operation S20. For example, a force for separating the mold structure MS and the body2from each other may be applied to the mold structure MS and the body2.

Referring toFIGS. 10 and 13, the upper electrode210and the reflective part300may be sequentially formed on the deformation part110in operation S30. The forming of the upper electrode210may include forming a conductive material layer on the top surface110uof the deformation part110. For example, the conductive material layer may be formed on the top surface110uof the deformation part110through a spray process. For example, the conductive material layer may include a silver nano-wire, a graphene, a carbon nano-tube, metal having flexibility, and a conductive polymer having flexibility

Although the upper electrode210and the reflective part300are not provided on the support part120in the drawing, the embodiment of the inventive concept is not limited thereto. In other exemplary embodiments, each of the upper electrode210and the reflective part300may extend from the top surface110uof the deformation part110to the top surface120uof the support part120. That is, the reflective part300may completely cover the top surface110uof the deformation part110and partially cover the top surface120uof the support part120.

The forming of the reflective part300may include forming a metal layer or a dielectric layer, which reflects light, on the top surface of the upper electrode210. For example, the forming of a metal layer or a dielectric layer may include performing a chemical vapor deposition or a physical vapor deposition. For example, the reflective part300may include gold (Au).

Referring toFIGS. 10 and 14, the additional support part400may be formed in the lower support trench LST in operation S40. The forming of the additional support part400may include inserting a ring made of a rigid material into the lower support trench LST. For example, the additional support part400may include acrylic.

Referring toFIGS. 9 and 10, the lower electrode220may be formed in the central hole CH in operation S50. The forming of the lower electrode220may include forming a conductive material layer on the bottom surface110bof the deformation part110. For example, the conductive material layer may be formed on the bottom surface110bof the deformation part110through a spray process. For example, the conductive material layer may include a silver nano-wire, a graphene, a carbon nano-tube, metal having flexibility, and a conductive polymer having flexibility

In order to deform the deformation part into the required shape, an electric field having a uniform size is necessarily applied into the deformation part. In order to form the electric field, the lower electrode and the upper electrode are necessarily aligned with each other.

Since the lower electrode220according to an embodiment of the inventive concept is formed in the central hold CH, the lower electrode220and the upper electrode210may be readily aligned with each other. The alignment may represent a state in which the lower electrode220faces the upper electrode210with the deformation part110therebetween. For example, although the upper electrode210extends from the top surface of the deformation part110to the top surface of the support part120, and the lower electrode220extends from the bottom surface110bof the deformation part110to the inner surface122of the support, the lower electrode220and the upper electrode210may face each other with the deformation part110disposed therebetween. Accordingly, the deformation part110may be controlled to have the required shape.

FIG. 15is a cross-sectional view taken along line I-I′ inFIG. 1of a reflective active variable lens according to exemplary embodiments of the inventive concept. For concise description, the substantially same contents as those described with reference toFIGS. 7 to 9will not be described.

Referring toFIG. 15, a reflective active variable lens30may include a body part3, an upper electrode210, a lower electrode220, a reflective part300, an additional support part400, and a packaging structure PS. The body part3may include a deformation part110and a support part120. The deformation part110, the upper electrode210, the lower electrode220, and the reflective part300may be the substantially same as the deformation part110, the upper electrode210, the lower electrode220, and the reflective part300, which are described with reference toFIGS. 7 to 9.

The support part120may include an upper support trench UST. The upper support trench UST may be a region in which a top surface120uof the support part120is recessed. The upper support trench UST may have a ring shape. The upper support trench UST may share a central axis with the support part120.

The packaging structure PS may surround the body part3. The packaging structure PS may extend along an edge of the body part3. The packaging structure PS may be made of a rigid material. The packaging structure PS may include a protruding portion that fills the upper support trench UST. The packaging structure PS may be coupled to the body part3by the protruding portion.

The packaging structure PS according to an embodiment of the inventive concept may be coupled to the body part3by the upper support trench UST. Accordingly, the reflective active variable lens30may be improved in structural stability.

FIG. 16is a bottom perspective view illustrating a reflective active variable lens according to exemplary embodiments of the inventive concept.FIG. 17is an exploded perspective view illustrating the reflective active variable lens inFIG. 16.FIG. 18is a cross-sectional view taken along line I-I′ inFIG. 1of the reflective active variable lens inFIG. 16. For concise description, the substantially same contents as those described with reference toFIGS. 7 to 9will not be described.

Referring toFIGS. 16 to 18, a reflective active variable lens40may include a body part4, an upper electrode210, a lower electrode220, a reflective part300, and an additional support part400. The body part4may include a deformation part110and a support part120. Except for a shape of an inner surface122of the support part120, the reflective active variable lens40according to an embodiment of the inventive concept may be the substantially same as the reflective active variable lens20described with reference toFIGS. 7 to 9.

Unlike the illustration inFIG. 9, the support part120may have a thickness that gradually decreases in a direction toward the deformation part110. The support part120may have a minimum thickness that is the substantially same as a thickness of the deformation part110. The inner surface122of the support part120may have a recessed shape. Accordingly, the support part120may have an internal diameter122dthat gradually increases from a bottom surface110bof the deformation part110to a bottom surface120bof the support part120. The internal diameter122dof the support part120may be a maximum distance between two points of the inner surface122of the support part120in a direction parallel to the top surface120uof the support part120. Accordingly, the internal diameter122dmay have a minimum value at the same level as the bottom surface110bof the deformation part110and a maximum value at the same level as the bottom surface120bof the support part120.

The support part120may have a thickness that gradually decreases in a direction toward the deformation part110. When the deformation part110is expanded, a portion of the support part120, which is disposed adjacent to the deformation part110, may be expanded together. Accordingly, a deformation speed of the deformation part110may be less than that of the deformation part110described with reference toFIGS. 1 to 4. When the deformation speed of the deformation part is fast, an element may be deteriorated. Since the deformation part110according to an embodiment of the inventive concept is deformed slowly, the reflective active variable lens40may be improved in durability. The reflective active variable lens40may have a focal position that is actively adjusted by the deformation of the deformation part110and the reflective part300.

FIG. 19is a cross-sectional view taken along line I-I′ inFIG. 1of a reflective active variable lens according to exemplary embodiments of the inventive concept. For concise description, the substantially same contents as those described with reference toFIGS. 16 to 18will not be described.

Referring toFIG. 19, a reflective active variable lens50may include a body part4, an upper electrode210, a lower electrode220, a reflective part300, and an additional support part400. The body part4may include a deformation part110and a support part120. Except for the lower electrode220, the reflective active variable lens50according to an embodiment of the inventive concept may be the substantially same as the reflective active variable lens20described with reference toFIGS. 7 to 9.

Unlike the illustration inFIG. 18, the lower electrode220may extend along an inner surface122from a bottom surface110bof the deformation part110to a bottom surface120bof the support part120. Although the additional support part400is not covered by the lower electrode220in the drawing, the embodiment of the inventive concept is not limited thereto. In other exemplary embodiments, the lower electrode220may be provided on a bottom surface of the additional support part400.

FIG. 20is a planar perspective view illustrating a reflective active variable lens according to exemplary embodiments of the inventive concept.FIG. 21is a cross-sectional view taken along line II-II′ inFIG. 20. For concise description, the substantially same contents as those described with reference toFIGS. 16 to 18will not be described.

Referring toFIGS. 20 to 21, a reflective active variable lens60may include a body part4, an upper reflective electrode212, a lower electrode220, a reflective part300, and an additional support part400. The body part4may include a deformation part110and a support part120. Except for the upper reflective electrode212, the reflective active variable lens60according to an embodiment of the inventive concept may be the substantially same as the reflective active variable lens40described with reference toFIGS. 16 to 18.

Unlike the illustration inFIG. 18, the upper reflective electrode212may be disposed on the deformation part110. The upper reflective electrode212may have a function of each of the upper electrode210and the reflective part300, which are described with reference toFIGS. 16 and 18. That is, the upper reflective electrode212may be applied with a voltage and reflect incident light. The upper reflective electrode212may include a metal thin-film having flexibility. For example, the upper reflective electrode212may include gold (Au).

The reflective active variable lens60according to an embodiment of the inventive concept may have a focal position that is actively adjusted by the deformation of the deformation part110and the reflective part300.

FIG. 22is a cross-sectional view taken along line II-II′ inFIG. 20of a reflective active variable lens according to exemplary embodiments of the inventive concept. For concise description, the substantially same contents as those described with reference toFIGS. 20 to 21will not be described.

Referring toFIG. 22, a reflective active variable lens70may include a body part4, an upper electrode210, a lower electrode220, a reflective part300, and an additional support part400. The body part4may include a deformation part110and a support part120. Except for the lower electrode220, the reflective active variable lens70according to an embodiment of the inventive concept may be the substantially same as the reflective active variable lens60described with reference toFIGS. 20 to 21.

Unlike the illustration inFIG. 21, the lower electrode220may extend along an inner surface122from a bottom surface110bof the deformation part110to a bottom surface120bof the support part120. Although the additional support part400is not covered by the lower electrode220in the drawing, the embodiment of the inventive concept is not limited thereto. In other exemplary embodiments, the lower electrode220may be provided on a bottom surface of the additional support part400.

According to the embodiment of the inventive concept, the reflective active variable lens may be improved in performance.

According to the embodiment of the inventive concept, the method of fabricating the reflective active variable lens may be improved in efficiency.

However, the effects of the embodiments of the inventive concept are not limited to the above description.