KR102726465B1 - Liquid lens module - Google Patents

Abstract

A liquid lens module according to an embodiment comprises a first liquid lens including a first cavity, and a plurality of first individual electrodes arranged to be spaced apart from each other with a first boundary portion including a plurality of boundary portions therebetween, and a second liquid lens including a second cavity arranged to overlap with the first cavity in the direction of an optical axis, and a plurality of second individual electrodes arranged to be spaced apart from each other with a second boundary portion including a plurality of boundary portions therebetween, wherein the first boundary portion and the second boundary portion are arranged so as not to overlap each other in a direction parallel to the optical axis.

Description

LIQUID LENS MODULE

The embodiment relates to a liquid lens module.

Users of portable devices want optical devices that have high resolution, are small in size, and have various shooting functions. For example, various shooting functions may mean at least one of an optical zoom function (zoom-in/zoom-out), an auto-focusing (AF) function, or an optical image stabilizer (OIS) function.

In the past, in order to implement the various shooting functions described above, a method was used to combine multiple lenses and directly move the combined lenses. However, if the number of lenses is increased in this way, the size of the optical device may increase.

Auto focus and image stabilization functions are performed by moving or tilting multiple lenses aligned along the optical axis in the direction perpendicular to the optical axis or the optical axis. At this time, since the lens section performing auto focus and the lens section performing image stabilization function in the optical device are provided separately from each other, there is a problem in that the overall size of the optical device increases.

United States Patent Publication No. US 2016/0299264 (Application No. SN:14/824945) United States Patent Publication No. US 2014/0347741 (Application No. SN:13/902766)

The embodiment provides a liquid lens module capable of performing a shake correction function precisely.

The technical problems to be solved in the embodiments are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

A liquid lens module according to an embodiment comprises: a first liquid lens including a first cavity and a plurality of first individual electrodes spaced apart from each other with a first boundary portion including a plurality of boundary portions interposed therebetween; and a second liquid lens including a second cavity and arranged to overlap with the first cavity in the direction of an optical axis, and a plurality of second individual electrodes spaced apart from each other with a second boundary portion including a plurality of boundary portions interposed therebetween, wherein the first boundary portion and the second boundary portion can be arranged so as not to overlap each other in a direction parallel to the optical axis.

For example, the minimum angle formed on a plane by a first virtual line connecting the first boundary portion from the optical axis passing through the center of the first cavity and the center of the second cavity and a second virtual line connecting the second boundary portion from the optical axis may be equal to or less than Δθ as follows.

Here, M represents the number of the first individual electrodes, and N represents the number of the second individual electrodes.

For example, each of the plurality of first individual electrodes and the second boundary portion may overlap each other in the direction parallel to the optical axis, and each of the plurality of second individual electrodes and the first boundary portion may overlap each other in the direction parallel to the optical axis.

For example, the first liquid lens may include a first lower plate including the first cavity in which conductive liquid and non-conductive liquid are disposed; a second lower plate disposed above and below the first lower plate; and a third lower plate disposed at the other of the above and below the first lower plate, and the second liquid lens may include a first upper plate including the second cavity in which conductive liquid and non-conductive liquid are disposed; a second upper plate disposed above and below the first upper plate; and a third upper plate disposed at the other of the above and below the first upper plate.

For example, one of the second and third lower plates and one of the second and third upper plates may face each other and be integral with each other.

For example, the first cavity may include first and second openings formed above and below the first lower plate, respectively, and the second cavity may include third and fourth openings formed above and below the first upper plate, respectively, and the sizes of the larger openings among the first and second openings and the larger openings among the third and fourth openings may be the same, and the sizes of the smaller openings among the first and second openings and the smaller openings among the third and fourth openings may be the same.

For example, the first boundary portion may be arranged in a direction corresponding to a side of the first liquid lens, and the second boundary portion may be arranged in a direction corresponding to a corner of the second liquid lens.

A liquid lens module according to an embodiment can perform an OIS function without or with reduced wavefront error even when no voltage is applied to the boundary separating a plurality of individual electrodes from each other, thereby improving the image quality provided by a device using the liquid lens module.

In addition, the effects obtainable in the present embodiment are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

Figure 1 shows a perspective view of a liquid lens module according to an embodiment.
Figures 2a and 2b illustrate a perspective view and a bottom view, respectively, of the first liquid lens illustrated in Figure 1.
Figures 3a and 3b illustrate a perspective view and a bottom view, respectively, of the second liquid lens illustrated in Figure 1.
Figure 4 shows a cross-sectional view of the liquid lens module cut along the line I-I' shown in Figure 1.
FIGS. 5A to 5C are bottom views illustrating the operation of a liquid lens module according to an embodiment.
FIGS. 6 (a) to 6 (c) are drawings for explaining a first operation example of a liquid lens module by comparative example.
FIGS. 7 (a) to 7 (c) are drawings for explaining a second operation example of a liquid lens module by comparative example.
Figures 8 (a) to (d) are drawings for explaining the operating characteristics of a liquid lens module according to an embodiment.
FIGS. 9A to 9F are graphs for comparing the characteristics of liquid lens modules according to comparative examples and embodiments.
Figure 10 is a table for comparing the characteristics of liquid lens modules by comparative examples and embodiments.
Fig. 11 shows a schematic block diagram of an optical device according to an embodiment.

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

However, the technical idea of the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, can be interpreted in consideration of the contextual meaning of the related technology.

In addition, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when it is described as “A and (or) at least one (or more) of B, C,” it may include one or more of all combinations that can be combined with A, B, C.

In addition, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

In addition, when a component is described as being “connected,” “coupled,” or “connected” to another component, it may include not only cases where the component is directly connected, coupled, or connected to the other component, but also cases where the component is “connected,” “coupled,” or “connected” by another component between the component and the other component.

In addition, when described as being formed or arranged “above or below” each component, above or below includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or arranged between the two components. Also, when expressed as “above or below,” it can include the meaning of the downward direction as well as the upward direction based on one component.

Hereinafter, a liquid lens module (100) according to an embodiment will be described using a Cartesian coordinate system, but the embodiment is not limited thereto. That is, according to the Cartesian coordinate system, the x-axis, the y-axis, and the z-axis are orthogonal to each other, and the x’-axis, the y’-axis, and the z’-axis are orthogonal to each other, but the embodiment is not limited thereto. That is, the x-axis, the y-axis, and the z-axis may intersect each other instead of being orthogonal to each other, and the x’-axis, the y’-axis, and the z’-axis may intersect each other instead of being orthogonal.

FIG. 1 shows a perspective view of a liquid lens module (100) according to an embodiment, FIGS. 2a and 2b show a perspective view and a bottom view, respectively, of a first liquid lens (110) shown in FIG. 1, FIGS. 3a and 3b show a perspective view and a bottom view, respectively, of a second liquid lens (120) shown in FIG. 1, and FIG. 4 shows a cross-sectional view of the liquid lens module (100) cut along the line I-I’ shown in FIG. 1.

Referring to FIGS. 1 to 4, the liquid lens module (100) according to the embodiment may include first and second liquid lenses (110, 120). As illustrated, the second liquid lens (120) may be placed on the first liquid lens (110), or, unlike illustrated, the first liquid lens (110) may be placed on the second liquid lens (120).

Hereinafter, the second liquid lens (120) is described as being positioned on the first liquid lens (110) in the liquid lens module (100), but the following description may also be applied when the first liquid lens (110) is positioned on the second liquid lens (120).

The first liquid lens (110) according to the embodiment may include a plurality of first liquids (LQ11, LQ12) of different types, first to third lower plates (P1L, P2L, P3L), and a plurality of first individual electrodes. In addition, although not shown, the first liquid lens (110) may further include a first common electrode and a first insulating layer.

A plurality of first liquids (LQ11, LQ12) are filled, accommodated, or placed in a first cavity (Cavity) (CA1), and may include a non-conductive liquid (or, non-conductive first liquid, hereinafter referred to as “1-1 liquid”) (LQ11) and a conductive liquid (or, conductive first liquid, hereinafter referred to as “1-2 liquid”) (LQ12). The 1-1 liquid (LQ11) and the 1-2 liquid (LQ12) do not mix with each other, and a first interface (BO1) may be formed at a contact portion between the 1-1 and 1-2 liquids (LQ11, LQ12). For example, the 1-2 liquid (LQ12) may be placed on the 1-1 liquid (LQ11), but the embodiment is not limited thereto, and their positions may be switched.

According to an embodiment, the 1-1 liquid (LQ11) may be placed on the 1-2 liquid (LQ12).

The first lower plate (P1L) may include a first cavity (CA1). The first inner side surface (i1) of the first lower plate (P1L) may form a side of the first cavity (CA1). At this time, the first inner side surface (i1) of the first lower plate (P1L) may be inclined as illustrated in FIG. 4, but the embodiment is not limited thereto and may be formed to be inclined in the opposite direction.

The first cavity (CA1) may include first and second openings (O1, O2) formed above and below the first lower plate (P1L), respectively. To facilitate understanding, the first opening (O1), which is not visible in the bottom view of Fig. 2b, is drawn with a dotted line.

That is, the first cavity (CA1) may be defined as a region surrounded by the first inner surface (i1) of the first lower plate (P1L), the first opening (O1) and the second opening (O2). As such, the first cavity (CA1) may include the first opening (O1) and the second opening (O2). The diameter of the wider opening among the first and second openings (O1, O2) may vary depending on the field of view (FOV) required by the first liquid lens (110) or the role to be performed in the optical device including the first liquid lens (110). According to an embodiment, the size (or area or width) of the first opening (O1) may be larger than the size (or area or width) of the second opening (O2). Here, the size of each of the first and second openings (O1, O2) may be a cross-sectional area in a horizontal direction (for example, in the x-axis and y-axis directions). For example, the size of each of the first and second openings (O1, O2) may mean the radius if the cross-section of the opening is circular, or the length of the diagonal if the cross-section of the opening is square.

The first cavity (CA1) is a portion through which light transmits. Accordingly, the first lower plate (P1L) forming the first cavity (CA1) may be made of a transparent material, or may include impurities to prevent light from transmitting easily.

Light may enter the first cavity (CA1) through a first opening (O1) that is wider than the second opening (O2) and exit through the second opening (O2), or may enter the first cavity (CA1) through a second opening (O2) that is narrower than the first opening (O1) and exit through the first opening (O1).

In addition, the second lower plate (P2L) may be positioned above or below the first lower plate (P1L), and the third lower plate (P3L) may be positioned above or below the first lower plate (P1L). For example, as illustrated in FIG. 4, the second lower plate (P2L) may be positioned above the first lower plate (P1L), and the third lower plate (P3L) may be positioned below the first lower plate (P1L). In this case, the second lower plate (P2L) may be positioned above the first cavity (CA1), and the third lower plate (P3L) may be positioned below the first cavity (CA1).

The second lower plate (P2L) and the third lower plate (P3L) may be arranged opposite each other with the first lower plate (P1L) therebetween. Additionally, at least one of the second lower plate (P2L) or the third lower plate (P3L) may be omitted.

At least one of the second or third lower plates (P2L, P3L) may have a rectangular planar shape and may have a portion thereof escaped to expose a portion of an electrode to be described later. Each of the second and third lower plates (P2L, P3L) may be a region through which light passes and may be made of a light-transmitting material. For example, each of the second and third lower plates (P2L, P3L) may be made of glass and may be formed of the same material for the convenience of the process. In addition, the edge of each of the second and third lower plates (P2L, P3L) may have a rectangular shape, but is not necessarily limited thereto.

The second lower plate (P2L) can have a configuration that allows incident light to proceed into the first cavity (CA1) of the first lower plate (P1L), but the light path can also proceed in the opposite direction. The third lower plate (P3L) can have a configuration that allows light passing through the first cavity (CA1) of the first lower plate (P1L) to be emitted, but can also have a configuration that allows light to be emitted in the opposite direction. The second lower plate (P2L) can be in direct contact with the first-second liquid (LQ12).

Additionally, the actual effective lens area of the first liquid lens (110) may be narrower than the diameter of the narrower second opening (O2) among the first and second openings (O1, O2) of the first lower plate (P1L).

Meanwhile, the first common electrode (not shown) may be arranged on one surface of the first lower plate (P1L) (e.g., above the first lower plate (P1L)), and the plurality of first individual electrodes may be arranged on the other surface of the first lower plate (P1L) (e.g., below the first lower plate (P1L)).

Additionally, each of the plurality of first individual electrodes may be arranged to extend from between the first and third lower plates (P1L, P3L) to a portion of the first inner surface (i1) of the first lower plate (P1L), or may be arranged on the entire first inner surface (i1).

For convenience of explanation, FIGS. 2A and 2B illustrate a case where each of the plurality of first individual electrodes is arranged on the entire first inner surface (i1) of the first lower plate (P1L). In this case, the plurality of first individual electrodes can be arranged sequentially in a clockwise direction in the first cavity (CA1).

Additionally, each of the plurality of first individual electrodes may be arranged to extend from the first inner surface (i1) of the first lower plate (P1L) to above the first lower plate (P1L) and to be spaced apart from the first common electrode.

A part of the first common electrode disposed on the first lower plate (P1L) is exposed to the first-second liquid (LQ12) having conductivity and can be in direct contact with the first-second liquid (LQ12). On the other hand, although not shown, a first insulating layer is disposed between each of the plurality of first individual electrodes and the first-first and first-second liquids (LQ11, LQ12), so that each of the plurality of first individual electrodes and the first-first and first-second liquids (LQ11, LQ12) can be electrically separated from each other.

The first common electrode may be one electrode, while the first individual electrodes may be multiple electrodes. For example, as illustrated, the number of the first individual electrodes may be four, or, unlike illustrated, may be eight, and the embodiment is not limited to a specific number of the first individual electrodes.

Hereinafter, the plurality of first individual electrodes are described as including 1-1 to 1-4 individual electrodes (LLD1 to LLD4) sequentially arranged in a clockwise (or counterclockwise) direction centered on the optical axis (LX). However, the following description may also be applied even when the plurality of first individual electrodes include plural (for example, 8) individual electrodes sequentially arranged in a clockwise (or counterclockwise) direction centered on the optical axis (LX).

Each of the first common electrode and the first individual electrodes (LLD1 to LLD4) can be made of a conductive material, for example, a metal.

In addition, the first insulating layer may be arranged to cover the entirety of the first individual electrodes (LLD1 to LLD4) arranged on the first inner surface (i1) of the first cavity (CA1). In addition, the first insulating layer may be arranged to cover a part of the first common electrode and the entirety of the first individual electrodes (LLD1 to LLD4) on the upper surface of the first lower plate (P1L). In this way, the first insulating layer may block contact between the first individual electrodes (LLD1 to LLD4) and the 1-1 liquid (LQ11), contact between the first individual electrodes (LLD1 to LLD4) and the 1-2 liquid (LQ12), and contact between the third lower plate (P3L) and the 1-1 liquid (LQ11).

The first insulating layer covers the first individual electrodes (LLD1 to LLD4) and exposes a part of the first common electrode, so that electrical energy can be applied to the first-second liquid (LQ12) having conductivity through the first common electrode.

Meanwhile, the second liquid lens (120) according to the embodiment may include a plurality of second liquids (LQ21, LQ22) of different types, first to third upper plates (P1U, P2U, P3U), and a plurality of second individual electrodes. In addition, although not shown, the second liquid lens (120) may further include a second common electrode and a second insulating layer.

A plurality of second liquids (LQ21, LQ22) are filled, accommodated, or placed in the second cavity (CA2), and may include a non-conductive liquid (or, non-conductive second liquid, hereinafter referred to as “2-1 liquid”) (LQ21) and a conductive liquid (or, conductive second liquid, hereinafter referred to as “2-2 liquid”) (LQ22). The 2-1 liquid (LQ21) and the 2-2 liquid (LQ22) do not mix with each other, and a second interface (BO2) may be formed at a contact portion between the 2-1 and 2-2 liquids (LQ21, LQ22). For example, as illustrated, the 2-2 liquid (LQ22) may be placed on the 2-1 liquid (LQ21), but the embodiment is not limited thereto. In another embodiment, unlike the one shown, the 2-1 liquid (LQ21) may be placed on the 2-2 liquid (LQ22).

The first upper plate (P1U) may include a second cavity (CA2). The second inner side (i2) of the first upper plate (P1U) may define a side of the second cavity (CA2). At this time, the second inner side (i2) of the first upper plate (P1U) may be inclined as illustrated in FIG. 4, but the embodiment is not limited thereto and may be formed to be inclined in the opposite direction.

The second cavity (CA2) may include third and fourth openings (O3, O4) formed below and above the first upper plate (P1U), respectively. To facilitate understanding, the third opening (O3), which is not visible in the bottom view of Fig. 3b, is drawn with a dotted line.

The second cavity (CA2) may be defined as a region surrounded by the second inner surface (i1), the third opening (O3), and the fourth opening (O4) of the first upper plate (P1U). The second cavity (CA2) may be arranged at a position corresponding to the first cavity (CA1), and may be arranged to overlap the first cavity (CA1) in a direction parallel to (or in parallel with) the optical axis (LX).

Among the third and fourth apertures (O3, O4), the diameter of the wider aperture may vary depending on the field of view (FOV) required by the second liquid lens (120) or the role to be played by the optical device including the second liquid lens (120). According to an embodiment, the size (or area or width) of the third aperture (O3) may be larger than the size (or area or width) of the fourth aperture (O4). Here, the size of each of the third and fourth apertures (O3, O4) may be a cross-sectional area in a horizontal direction (e.g., in the x-axis and y-axis directions). For example, the size of each of the third and fourth apertures (O3, O4) may mean a radius if the cross-section of the aperture is circular, and may mean the length of a diagonal if the cross-section of the aperture is square. Each of the third and fourth apertures (O3, O4) may have a circular cross-sectional shape.

The second cavity (CA2) is a portion through which light transmits. Accordingly, the first upper plate (P1U) forming the second cavity (CA2) may be made of a transparent material or may include impurities to prevent light from transmitting easily.

Light may enter the second cavity (CA2) through a third aperture (O3) that is wider than the fourth aperture (O4) and exit through the fourth aperture (O4), or may enter the second cavity (CA2) through a fourth aperture (O4) that is narrower than the third aperture (O3) and exit through the third aperture (O3).

Hereinafter, light is described as being incident through the third aperture (O3) and exiting through the fourth aperture (O4), and light exiting from the fourth aperture (O4) is described as being incident through the first aperture (O1) and exiting through the second aperture (O2). However, the following description may also be applied to a case where light is incident through the second aperture (O2) and exiting through the first aperture (O1), and light exiting from the first aperture (O1) is incident through the fourth aperture (O4) and exiting through the third aperture (O3).

In addition, the second upper plate (P2U) may be positioned above or below the first upper plate (P1U), and the third upper plate (P3U) may be positioned above or below the first upper plate (P1U). For example, as illustrated in FIG. 4, the second upper plate (P2U) may be positioned above the first upper plate (P1U), and the third upper plate (P3U) may be positioned below the first upper plate (P1U). In this case, the second upper plate (P2U) may be positioned above the second cavity (CA2), and the third upper plate (P3U) may be positioned below the second cavity (CA2).

In an embodiment, one of the second and third lower plates (P2L, P3L) and one of the second and third upper plates (P2U, P3U) may face each other and be integral with each other. For example, referring to FIG. 4, the second lower plate (P2L) and the third upper plate (P3U) may face each other and be integrally formed. The overall size of the liquid lens module (100) including the second lower plate (P2L) and the third upper plate (P3U) that are integral with each other can be reduced compared to a liquid lens module including the second lower plate (P2L) and the third upper plate (P3U) that are spaced apart from each other rather than integral with each other.

The second upper plate (P2U) and the third upper plate (P3U) may be arranged opposite each other with the first upper plate (P1U) interposed therebetween. Additionally, at least one of the second upper plate (P2U) or the third lower plate (P3U) may be omitted.

At least one of the second or third upper plates (P2U, P3U) may have a rectangular planar shape and may have a portion thereof escaped to expose a portion of an electrode to be described later. Each of the second and third upper plates (P2U, P3U) may be a region through which light passes and may be made of a light-transmitting material. For example, each of the second and third upper plates (P2U, P3U) may be made of glass and may be formed of the same material for the convenience of the process. In addition, an edge of each of the second and third upper plates (P2U, P3U) may have a rectangular shape, but is not necessarily limited thereto.

The second upper plate (P2U) may have a configuration that allows incident light to proceed into the second cavity (CA2) of the first upper plate (P1U). The third upper plate (P3U) may have a configuration that allows light passing through the second cavity (CA2) of the first upper plate (P1U) to be emitted.

Additionally, the actual effective lens area of the second liquid lens (120) may be narrower than the diameter of the narrow fourth opening (O4) among the third and fourth openings (O3, O4) of the first upper plate (P1L).

Meanwhile, a second common electrode (not shown) may be arranged on one surface of the first upper plate (P1U) (e.g., above the first upper plate (P1U)), and a plurality of second individual electrodes may be arranged on the other surface of the first upper plate (P1U) (e.g., below the first upper plate (P1U)).

In addition, each of the plurality of second individual electrodes may be arranged to extend from between the first and third upper plates (P1U, P3U) to a part of the second inner surface (i2) of the first upper plate (P1U), or may be arranged on the entire second inner surface (i2). For convenience of explanation, FIGS. 3A and 3B illustrate a case where each of the plurality of second individual electrodes is arranged on the entire second inner surface (i2) of the first upper plate (P1U). In this case, the plurality of second individual electrodes may be arranged sequentially in a clockwise direction (or counterclockwise direction) in the second cavity (CA2).

Additionally, each of the plurality of second individual electrodes may be arranged to extend from the second inner surface (i2) of the first upper plate (P1U) to above the first upper plate (P1U) and spaced apart from the second common electrode.

A part of the second common electrode disposed on the first upper plate (P1U) is exposed to the second-second liquid (LQ22) having conductivity and can be in direct contact with the second-second liquid (LQ22). On the other hand, although not shown, a second insulating layer is disposed between each of the plurality of second individual electrodes and the second-first and second-second liquids (LQ21, LQ22), so that each of the plurality of second individual electrodes and the second-first and second-second liquids (LQ21, LQ22) can be electrically separated from each other.

The second common electrode may be one, while the second individual electrodes may be multiple electrodes. For example, as illustrated, the number of the second individual electrodes may be four, or, unlike illustrated, may be multiple (e.g., eight), and the embodiment is not limited to a specific number of second individual electrodes.

Hereinafter, the plurality of second individual electrodes are described as including 2-1 to 2-4 individual electrodes (LLU1 to LLU4) sequentially arranged in a clockwise (or counterclockwise) direction centered on the optical axis (LX). However, the following description may also be applied when the plurality of second individual electrodes include 8 individual electrodes sequentially arranged in a clockwise (or counterclockwise) direction centered on the optical axis (LX).

Each of the second common electrode and the second individual electrodes (LLU1 to LLU4) can be made of a conductive material.

In addition, the second insulating layer may be arranged to cover the entirety of the second individual electrodes (LLU1 to LLU4) arranged on the second inner surface (i2) of the second cavity (CA2). In addition, the second insulating layer may be arranged to cover a part of the second common electrode and the entirety of the second individual electrodes (LLU1 to LLU4) on the upper surface of the first upper plate (P1U). In this way, the second insulating layer may block contact between the second individual electrodes (LLU1 to LLU4) and the second-1 liquid (LQ21), contact between the second individual electrodes (LLU1 to LLU4) and the second-2 liquid (LQ22), and contact between the third upper plate (P3U) and the second-1 liquid (LQ21).

The second insulating layer covers the second individual electrodes (LLU1 to LLU4) and exposes a portion of the second common electrode, so that electrical energy can be applied to the second-2 liquid (LQ22) having conductivity through the second common electrode.

Each of the first and second liquid lenses (110, 120) can perform an optical image stabilizer (OIS) function or an auto-focusing (AF) function.

When the liquid lens performs the AF function and the OIS function, wavefront error (WFE) may occur. Wavefront error (WFE) may deteriorate the image quality, and especially when performing the OIS function, the wavefront error (WFE) may become significantly large, which may deteriorate the image quality.

Hereinafter, the configuration of a liquid lens module (100) according to an embodiment for eliminating or reducing wavefront errors will be described in detail.

Referring to FIGS. 2A and 2B, a plurality of first individual electrodes (LLD1 to LLD4) may be arranged spaced apart from each other with a boundary (or disconnection) (hereinafter referred to as a “first boundary”) (SP11 to SP14) therebetween.

For example, the 1-1 individual electrode (LLD1) and the 1-2 individual electrode (LLD2) may be arranged so as to be electrically spaced apart from each other with a first boundary portion (hereinafter referred to as “1-1 boundary portion”) (SP11) therebetween. The 1-2 individual electrode (LLD2) and the 1-3 individual electrode (LLD3) may be arranged so as to be electrically spaced apart from each other with a first boundary portion (hereinafter referred to as “1-2 boundary portion”) (SP12) therebetween. The 1-3 individual electrode (LLD3) and the 1-4 individual electrode (LLD4) may be arranged so as to be electrically spaced apart from each other with a first boundary portion (hereinafter referred to as “1-3 boundary portion”) (SP13) therebetween. The 1-4 individual electrode (LLD4) and the 1-1 individual electrode (LLD1) may be electrically spaced apart from each other with a first boundary portion (hereinafter referred to as “1-4 boundary portion”) (SP14) therebetween. To this end, a first insulating layer may be disposed on each of the 1-1 to 1-4 boundary portions (SP11 to SP14). In this way, the first boundary portion may include a plurality of boundary portions (SP11 to SP14).

A plurality of first individual electrodes (LLD1 to LLD4) may have a planar shape arranged to be spaced apart from each other by the same angular distance (hereinafter referred to as “first angular distance”) based on the optical axis (LX). Here, the angular distance may mean the angle between two straight lines when connecting two points from one point by a straight line. For example, as illustrated in FIG. 2B, when each of the plurality of first individual electrodes (LLD1 to LLD4) is arranged on the first inner surface (i1) of the first lower plate (P1L), when the point where the first-first boundary portion (SP11) and the second opening (O2) of the first-first individual electrode (LLD1) are respectively contacted as ‘P01’ and the point where the first-first boundary portion (SP11) and the second opening (O2) of the first-second individual electrode (LLD2) are respectively contacted as ‘P02’, when the center of the first cavity (CA1) contacting the optical axis (LX) and the two points (P01, P02) are connected by a straight line, the angle between the two straight lines is ‘θ11’. At this time, the first angular distance (hereinafter referred to as the “1-1 angular distance”) by which the 1-1st and 1-2nd individual electrodes (LLD1 and LLD2) are spaced apart based on the optical axis (LX) may be θ11. In addition, the first angular distance (hereinafter referred to as the “1-2 angular distance”) by which the 1-2nd and 1-3rd individual electrodes (LLD2 and LLD3) are spaced apart based on the optical axis (LX) may be θ12. In addition, the first angular distance (hereinafter referred to as the “1-3 angular distance”) by which the 1-3rd and 1-4th individual electrodes (LLD3 and LLD4) are spaced apart based on the optical axis (LX) may be θ13. In addition, the first angular distance (hereinafter referred to as the “1-4 angular distance”) by which the 1-4th and 1-1st individual electrodes (LLD4 and LLD1) are spaced apart based on the optical axis (LX) may be θ14.

According to an embodiment, the plurality of first angular distances, i.e., the 1-1 to 1-4 angular distances (θ11, θ12, θ13, θ14), may be equal to each other. In addition, the plurality of first individual electrodes (LLD1 to LLD4) may have the same (low) area.

In addition, according to one embodiment, the first boundary portion may be arranged in a direction corresponding to a side of the first liquid lens (110), and the second boundary portion may be arranged in a direction corresponding to an edge (or corner) of the second liquid lens (120). For example, as illustrated, each of the first-1 to first-4 boundary portions (SP11 to SP14) on the bottom surface may be in contact with a side of the first liquid lens (110), and each of the second-1 to second-4 boundary portions (SP21 to SP24) may be in contact with an edge of the second liquid lens (120).

Alternatively, according to another embodiment, the first boundary portion may be arranged in a direction corresponding to an edge (or corner) of the first liquid lens (110), and the second boundary portion may be arranged in a direction corresponding to an edge of the second liquid lens (120). For example, unlike as illustrated, each of the first-1 to first-4 boundary portions (SP11 to SP14) on the bottom surface may contact an edge of the first liquid lens (110), and each of the second-1 to second-4 boundary portions (SP21 to SP24) may contact an edge of the second liquid lens (120).

In addition, according to an embodiment, the plurality of first-1 to first-4th boundary portions (SP11 to SP14) may face each other in the first direction with respect to the center of the first cavity (CA1) in contact with the optical axis (LX). That is, the first-1 and first-3rd boundary portions (SP11, SP13) may face each other in the first direction (hereinafter, referred to as “1-1 direction”) with respect to the center (LX) of the first cavity (CA1), and the first-2 and first-4th boundary portions (SP12, SP14) may face each other in the first direction (hereinafter, referred to as “1-2 direction”) with respect to the center (LX) of the first cavity (CA1). Here, the 1-1 direction may be the x-axis direction, and the 1-2 direction may be the y-axis direction.

Referring to FIGS. 3A and 3B, a plurality of second individual electrodes (LLU1 to LLU4) may be arranged to be spaced apart from each other with a boundary (hereinafter referred to as a “second boundary”) (SP21 to SP24) therebetween. That is, the 2-1 individual electrode (LLU1) and the 2-2 individual electrode (LLU2) may be arranged to be electrically spaced apart from each other with the second boundary (hereinafter referred to as a “2-1 boundary”) (SP21) therebetween. The 2-2 individual electrode (LLU2) and the 2-3 individual electrode (LLU3) may be arranged to be electrically spaced apart from each other with the second boundary (hereinafter referred to as a “2-2 boundary”) (SP22) therebetween. The 2-3 individual electrode (LLU3) and the 2-4 individual electrode (LLU4) may be electrically spaced apart from each other with a second boundary portion (hereinafter referred to as “2-3 boundary portion”) (SP23) therebetween. The 2-4 individual electrode (LLU4) and the 2-1 individual electrode (LLU1) may be electrically spaced apart from each other with a second boundary portion (hereinafter referred to as “2-4 boundary portion”) (SP24) therebetween. To this end, a second insulating layer may be disposed on each of the 2-1 to 2-4 boundary portions (SP21 to SP24). In this way, the second boundary portion may include a plurality of boundary portions (SP21 to SP24).

The plurality of second individual electrodes (LLU1 to LLU4) may have a planar shape arranged to be spaced apart from each other by the same angular distance (hereinafter referred to as the “second angular distance”) based on the optical axis (LX). At this time, the second angular distance (hereinafter referred to as the “2-1 angular distance”) at which the 2-1st and 2-2nd individual electrodes (LLU1 and LLU2) are spaced apart from the optical axis (LX) may be θ21. In addition, the second angular distance (hereinafter referred to as the “2-2 angular distance”) at which the 2-2nd and 2-3rd individual electrodes (LLU2 and LLU3) are spaced apart from the optical axis (LX) may be θ22. In addition, the second angular distance (hereinafter referred to as the “2-3 angular distance”) at which the 2-3rd and 2-4th individual electrodes (LLU3 and LLU4) are spaced apart from the optical axis (LX) may be θ23. Additionally, the second angular distance (hereinafter referred to as “2-4 angular distance”) at which the 2nd-4th and 2nd-1st individual electrodes (LLU4 and LLU1) are spaced apart from the optical axis (LX) may be θ24.

According to an embodiment, a plurality of second angular distances, i.e., the 2-1 to 2-4 angular distances (θ21, θ22, θ23, θ24), may be equal to each other. In addition, a plurality of second individual electrodes (LLU1 to LLU4) may have the same (low) area.

In addition, according to an embodiment, a plurality of second boundary portions (SP21 to SP24) may face each other in the second direction with respect to the center of the second cavity (CA2) in contact with the optical axis (LX). That is, with respect to the center (LX) of the second cavity (CA2), the 2-1st and 2-3rd boundary portions (SP21, SP23) may face each other in the second direction (hereinafter, referred to as the ‘2-1 direction’), and with respect to the center (LX) of the second cavity (CA2), the 2-2nd and 2-4th boundary portions (SP22, SP24) may face each other in the second direction (hereinafter, referred to as the ‘2-2 direction’). Here, the 2-1 direction may be the y’-axis direction, and the 2-2 direction may be the x’-axis direction.

The first direction and the second direction described above are different directions, and when the number of first individual electrodes is M and the number of second individual electrodes is N, the minimum angle between the first direction and the second direction can be equal to or less than Δθ expressed in the following mathematical expression 1.

Referring to FIG. 2a, the first virtual line is defined as a virtual line connecting the first boundary portions (SP11 to SP14) with the optical axis (LX) passing through the center of the first cavity (CA1) and the center of the second cavity (CA2). For example, the first virtual line may include the 1-1 virtual line (IL11) and the 1-2 virtual line (IL12). The 1-1 virtual line (IL11) is a virtual straight line connecting the 1-1 boundary portion (SP11) and the 1-3 boundary portion (SP13) from the optical axis (LX), and the 1-2 virtual line (IL12) is a virtual straight line connecting the 1-2 boundary portion (SP12) and the 1-4 boundary portion (SP14) from the optical axis (LX).

In addition, referring to FIG. 3a, the second virtual line is defined as a virtual line connecting the second boundaries (SP21 to SP24) with the optical axis (LX) passing through the center of the first cavity (CA1) and the center of the second cavity (CA2). For example, the second virtual line may include a 2-1 virtual line (IL21) and a 2-2 virtual line (IL22). The 2-1 virtual line (IL21) is a virtual straight line connecting the 2-1 boundary (SP21) and the 2-3 boundary (SP23) from the optical axis (LX), and the 2-2 virtual line (IL22) is a virtual straight line connecting the 2-2 boundary (SP22) and the 2-4 boundary (SP24) from the optical axis (LX).

According to an embodiment, the minimum angle formed by the first virtual line and the second virtual line on the plane may be equal to or less than Δθ expressed in the above-described mathematical expression 1.

For example, when M = N = 4 as illustrated, Δθ can be 45°. That is, the minimum angle between the x-axis direction, which is the 1-1 direction, and the x’-axis direction, which is the 2-2 direction, can be equal to or less than 45°, and the minimum angle between the y-axis direction, which is the 1-2 direction, and the y’-axis direction, which is the 2-1 direction, can be equal to or less than 45°. That is, the minimum angle that the first virtual line and the second virtual line form on the plane can be equal to or less than 45°.

However, unlike as shown, when M=N=8, the minimum angle between the first direction and the second direction may be equal to or less than 22.5°. That is, the minimum angle formed by the first virtual line and the second virtual line on the plane may be equal to or less than 22.5°.

As described above, except that the direction in which the first boundary portions electrically insulating the plurality of first individual electrodes face each other with respect to the optical axis (LX) is different from the direction in which the second boundary portions electrically insulating the plurality of second individual electrodes face each other with respect to the optical axis (LX), the first and second liquid lenses (110, 120) may have the same configuration. In this way, according to an embodiment, the first boundary portion and the second boundary portion may be arranged so as not to overlap each other in a direction parallel to the optical axis (LX) (for example, in the z-axis direction).

That is, the first angular distances (θ11, θ12, θ13, θ14) and the second angular distances (θ21, θ22, θ23, θ24) may be equal to each other. In addition, the sizes of the larger first opening (O1) among the first and second openings (O1, O2) and the larger third opening (O3) among the third and fourth openings (O3, O4) may be equal to each other. In addition, the sizes of the smaller second opening (O2) among the first and second openings (O1, O2) and the smaller fourth opening (O4) among the third and fourth openings (O3, O4) may be equal to each other. In this case, each of the plurality of first individual electrodes (LLD1 to LLD4) and the second boundary portions (SP21 to SP24) may overlap each other in a direction (for example, in the z-axis direction) parallel to (or parallel to) the optical axis (LX). In addition, each of the plurality of second individual electrodes (LLU1 to LLU4) and the first boundary portion (SP11 to SP14) can overlap each other in a direction parallel to (or in parallel with) the optical axis (LX). This will be examined in detail as follows.

For example, the 1-1 individual electrode (LLD1) and the 2-1 boundary portion (SP21) may overlap each other in the z-axis direction, the 1-2 individual electrode (LLD2) and the 2-2 boundary portion (SP22) may overlap each other in the z-axis direction, the 1-3 individual electrode (LLD3) and the 2-3 boundary portion (SP23) may overlap each other in the z-axis direction, and the 1-4 individual electrode (LLD4) and the 2-4 boundary portion (SP24) may overlap each other in the z-axis direction.

In addition, the 2-1 individual electrode (LLU1) and the 1-4 boundary portion (SP14) overlap each other in the z-axis direction, the 2-2 individual electrode (LLU2) and the 1-1 boundary portion (SP11) overlap each other in the z-axis direction, the 2-3 individual electrode (LLU3) and the 1-2 boundary portion (SP12) overlap each other in the z-axis direction, and the 2-4 individual electrode (LLU4) and the 1-3 boundary portion (SP13) can overlap each other in the z-axis direction.

Additionally, a virtual horizontal plane extending along each of the first boundary portions in the z-axis direction can bisect the second individual electrode. Additionally, a virtual horizontal plane extending along each of the second boundary portions in the z-axis direction can bisect the first individual electrode.

Meanwhile, although not shown, the liquid lens module (100) according to the embodiment may further include a first lower connection substrate, a second lower connection substrate, a first upper connection substrate, and a second upper connection substrate.

The first lower connection substrate can be electrically connected to electrode pads formed on the main substrate (not shown) through connection pads electrically connected to the first common electrode. The second lower connection substrate can be electrically connected to electrode pads formed on the main substrate through connection pads electrically connected to each of the plurality of first individual electrodes (LLD1 to LLD4).

Additionally, the first upper connection substrate can be electrically connected to the electrode pad formed on the main substrate through a connection pad electrically connected to the second common electrode. The second upper connection substrate can be electrically connected to the electrode pad formed on the main substrate through a connection pad electrically connected to the second individual electrodes (LLU1 to LLU4).

For example, each of the first lower side and first upper side connecting boards may be implemented as an FPCB or a single metal board (conductive metal plate), and each of the second lower side and second upper side connecting boards may be implemented as a flexible printed circuit board (FPCB), but the embodiment is not limited thereto.

The first lower connection substrate can transmit one driving voltage (hereinafter, referred to as “common voltage”) to the first first common electrode, and the second lower connection substrate can transmit M different voltages (hereinafter, referred to as “individual voltages”) to the plurality of first individual electrodes (LLD1 to LLD4), respectively. The common voltage may include a DC voltage or an AC voltage, and when the common voltage is applied in a pulse form, the width or duty cycle of the pulse may be constant. That is, the driving voltage may be supplied to the first liquid lens (110) through the first lower connection substrate and the second lower connection substrate.

The first upper connection substrate can transmit one common voltage to the second common electrode, and the second upper connection substrate can transmit N different voltages to the plurality of second individual electrodes (LLU1 to LLU4). That is, a driving voltage can be supplied to the second liquid lens (120) through the first upper connection substrate and the second upper connection substrate.

In response to the driving voltage, the curvature of the first interface (BO1) formed within the first liquid lens (110) changes, and the curvature of the second interface (BO2) formed within the second liquid lens (120) changes, so that the liquid lens module (100) can perform the AF function.

Alternatively, the tilting angle of the first interface (BO1) formed within the first liquid lens (110) changes in response to the driving voltage, and the tilting angle of the second interface (BO2) formed within the second liquid lens (120) changes in response to the driving voltage, so that the liquid lens module (100) can perform the OIS function.

FIGS. 5A to 5C are bottom views for explaining the operation of a liquid lens module (100) according to an embodiment. To aid understanding, in each of FIGS. 5A to 5C, the first and third openings (O1, O3) that are not visible are each drawn with a dotted line.

In order to correct the shaking or vibration of the liquid lens module (100) in the y-axis direction, as illustrated in FIG. 5a, a negative voltage (-V) may be applied to each of the 1-1 and 1-4 individual electrodes (LLD1, LLD4) of the first liquid lens (110), a positive voltage (+V) may be applied to each of the 1-2 and 1-3 individual electrodes (LLD2, LLD3), a negative voltage (-V) may be applied to each of the 2-1 individual electrode (LLU1) of the second liquid lens (120), and a positive voltage (+V) may be applied to each of the 2-3 individual electrodes (LLU3).

Alternatively, in order to compensate for the shaking or vibration of the liquid lens module (100) in the x-axis direction, as illustrated in FIG. 5b, a positive voltage (+V) may be applied to each of the first-1 and first-2 individual electrodes (LLD1, LLD2) of the first liquid lens (110), a negative voltage (-V) may be applied to each of the first-3 and first-4 individual electrodes (LLD3, LLD4), a positive voltage (+V) may be applied to the second-2 individual electrode (LLU2) of the second liquid lens (120), and a negative voltage (-V) may be applied to the second-4 individual electrode (LLU4).

Alternatively, in order to compensate for the liquid lens module (100) shaking or vibrating in a diagonal direction (e.g., in the x’-axis direction), as illustrated in FIG. 5c, a positive voltage (+V) may be applied to the first-second individual electrode (LLD2) of the first liquid lens (110), a negative voltage (-V) may be applied to the first-fourth individual electrode (LLD4), a positive voltage (+V) may be applied to the second-second and second-third individual electrodes (LLU2, LLU3) of the second liquid lens (120), and a negative voltage (-V) may be applied to the second-first and second-fourth individual electrodes (LLU1, LLU4), respectively.

Hereinafter, a liquid lens module (100) according to a comparative example and an exemplary example is compared and explained with reference to the attached drawings.

FIGS. 6 (a) to 6 (c) are drawings for explaining a first operation example of a liquid lens module by a comparative example, and FIGS. 7 (a) to 7 (c) are drawings for explaining a second operation example of a liquid lens module by a comparative example.

Figures 6 (a) and 7 (a) show bottom perspective views of a liquid lens module according to a comparative example. Here, the liquid lens module according to the comparative example is implemented with one liquid lens, and the liquid lens may include a plurality of individual electrodes (LL1 to LL4) and a plurality of boundary portions (SP1 to SP4).

The plurality of individual electrodes (LL1 to LL4) and the plurality of boundary portions (SP1 to SP4) can perform the same role as the plurality of first individual electrodes (LLU1 to LLU4) and the plurality of first boundary portions (SP11 to SP14) according to the embodiment, respectively.

FIG. 6 (b) and FIG. 7 (b) are drawings for explaining the wave front error (WFE) caused when the liquid lens module according to the comparative example operates in different first and second operation examples, respectively.

Figures 6 (c) and 7 (c) show cross-sectional views of a liquid lens module according to a comparative example. Here, the liquid lens module according to the comparative example may include first and second liquids (LQ1, LQ2) and a plurality of plates (P1 to P3).

The first and second liquids (LQ1, LQ2) and the plurality of plates (P1 to P3) can perform the same roles as the first-first and first-second liquids (LQ11, LQ12) and the plurality of first to third lower plates (P1L to P3L) according to the embodiment, respectively.

In the first operation example, as illustrated in Fig. 6 (a), a positive voltage (+V) is applied to each of the first and fourth individual electrodes (LL1, LL4), and a negative voltage (-V) is applied to each of the second and third individual electrodes (LL3, LL4), so that the interface (BO) of the two liquids (LQ1, LQ2) can be tilted at a predetermined angle in the y-axis direction (or, x-axis direction), as illustrated in Fig. 6 (c). At this time, the edges (A, B) of the interface (BO) may be distorted, so that wavefront errors (WFE1, WFE2) may occur, as illustrated in Fig. 6 (b).

In the second operation example, as illustrated in Fig. 7 (a), a positive voltage (+V) is applied to the first individual electrode (LL1) and a negative voltage (-V) is applied to the third individual electrode (LL3), so that the interface (BO) of two liquids (LQ1, LQ2) can be tilted at a predetermined angle in the diagonal direction between the -x-axis direction and the +y-axis direction, as illustrated in Fig. 7 (c). At this time, the edges (C, D) of the interface (BO) are distorted, so that wavefront errors (WFE1, WFE2) may occur, as illustrated in Fig. 7 (b).

Even though the width of each of the boundaries (SP1 to SP4) by the comparative example is small, such as several tens of μm, since the electrowetting phenomenon does not occur in the boundaries (SP1 to SP4) to which no voltage is applied, wavefront errors (WFE1, WFE2) may occur as shown in Fig. 6 (b) and Fig. 7 (b).

In the case of the liquid lens module by comparison, when the same voltage is applied to the four individual electrodes (LL1 to LL4) to perform the AF function, no wavefront error occurs, but when unequal voltages are applied to the individual electrodes (LL1 to LL4) to perform the OIS function as shown in FIGS. 6 and 7, a wavefront error occurs, which may deteriorate the image quality.

Figures 8 (a) to (d) are drawings for explaining the operating characteristics of a liquid lens module (100) according to an embodiment.

FIG. 8 (a) shows an exploded perspective view of the liquid lens module (100) shown in FIG. 1, FIG. 8 (b) shows the WFE characteristics of the liquid lens module (100) shown in FIG. 1, FIG. 8 (c) corresponds to the cross-sectional view shown in FIG. 4, and FIG. 8 (d) shows an equivalent cross-sectional view of the liquid lens module (100) according to an embodiment.

In FIGS. 8 (a) to 8 (c), the same reference numerals are used for the same parts as in FIGS. 1 to 5c, and thus, redundant descriptions are omitted. In addition, the liquid lens module (100) illustrated in FIGS. 8 (a) to (c) operates in the same manner as in FIG. 5b. Accordingly, as described above in FIG. 5b, the corresponding voltage can be applied to the plurality of first and second individual electrodes.

Even if the edges (A, B) of the first interface (BO1) in the first liquid lens (110) are distorted and the edges (C, D) of the second interface (BO2) in the second liquid lens (120) are distorted, the distortions at the edges (A, C) and the distortions at the edges (C, D) can be offset from each other. To this end, as described above, the minimum angle between the first direction in which the first boundary portions that electrically insulate the plurality of first individual electrodes face each other with respect to the optical axis (LX) and the second direction in which the second boundary portions that electrically insulate the plurality of second individual electrodes face each other with respect to the optical axis (LX) is Δθ, for example, 45°, and the first and second liquid lenses (110, 120) can have the same configuration.

Finally, even if the first width (w1) of the first boundary portions (SP11 to SP14) and the second width (w2) of the second boundary portions (SP21 to SP24) according to the embodiment are, for example, on the order of several tens of μm, when the liquid lens module (100) according to the embodiment as shown in Fig. 8 (a) is equivalent to the liquid lens module according to the comparative examples as shown in Figs. 6 and 7, the liquid lens module (100) according to the embodiment can improve image quality because the wavefront error is reduced or does not occur, as shown in Figs. 8 (b) and 8 (d).

FIGS. 9A to 9F are graphs for comparing the characteristics of liquid lens modules according to comparative examples and embodiments.

Fig. 10 is a table for comparing the characteristics of liquid lens modules according to comparative examples and embodiments. Here, ‘Static tilt’ means a state in which the tilted shape of the interface (BO) of two different liquids (LQ1, LQ2) is continuously maintained without changing for a predetermined period of time in the case of comparative examples, and a state in which the tilted shape of the interface (BO1, BO2) is continuously maintained without changing for a predetermined period of time in the case of embodiments.

In each of FIGS. 9A to 9F, the horizontal axis represents time, and the vertical axis of each of FIGS. 9A to 9F and ‘WFE’ of FIG. 10 represent the size of the wavefront error (140) by the comparative example (for example, E1 illustrated in FIG. 6 (c) or E2 illustrated in FIG. 7 (c)) and the size of the wavefront error (150) by the embodiment, and the unit may be μm. Here, the wavefront error (150) by the embodiment means the sum of the wavefront error of the first interface (BO1) and the wavefront error of the second interface (BO2). In addition, in each of the graphs illustrated in FIGS. 9A to 9F, the vertical axis may also correspond to the angle at which the interface is tilted to correct shaking (or, hand shaking) in the liquid lens module by the comparative example and the embodiment.

In addition, FIGS. 9a to 9c show characteristics when the shaking of the liquid lens module or the device (e.g., a camera module or an optical device) including the liquid lens module is 0.3° and the excitation frequencies are 2 Hz, 6 Hz and 10 Hz, respectively. In addition, FIGS. 9d to 9f show characteristics when the shaking of the liquid lens module or the device (e.g., a camera module or an optical device) including the liquid lens module is 0.6° and the excitation frequencies are 2 Hz, 6 Hz and 10 Hz, respectively. Here, the excitation frequency may mean a frequency for experimentally or arbitrarily vibrating the device including the liquid lens module for testing the liquid lens module.

Referring to FIGS. 9A to 9F and FIG. 10, when examining wavefront errors while varying the shaking angle at various excitation frequencies, it can be seen that the liquid lens module (100) according to the embodiment has a wavefront error reduced by 2 to 2.8 times compared to the comparative example.

The liquid lens module (100) according to the above-described embodiment can be applied to various fields.

Hereinafter, an optical device (200) including a liquid lens module according to an embodiment will be described with reference to the attached drawings, but the optical device (200) according to the embodiment is not limited thereto.

Fig. 11 shows a schematic block diagram of an optical device (200) according to an embodiment.

The optical device (200) may include a prism unit (210), a liquid lens module (220), and a zooming unit (230). Here, the liquid lens module (220) may correspond to the liquid lens module (100) described above.

The prism unit (210) changes the path of light incident in the direction indicated by IN to the optical axis (LX) of the liquid lens module (220).

The liquid lens module (220) can perform OIS and AF functions on light whose light path has been changed in the prism unit (210) and output it to the zoom unit (230).

The zooming unit (230) zooms in/out the light passing through the liquid lens module (220). To this end, the zooming unit (230) may include a plurality of lenses (not shown) and an actuator (not shown) that moves the lenses in a direction parallel to the optical axis (LX) (for example, in the z-axis direction).

As described above with respect to the embodiments, only a few have been described, but various other forms of implementation are possible. The technical contents of the embodiments described above can be combined in various forms as long as they are not mutually incompatible technologies, and through this, they can be implemented as new embodiments.

Meanwhile, according to another embodiment, an optical device can be implemented using a camera module including a lens assembly having a liquid lens module (100). Here, the optical device can include a device capable of processing or analyzing an optical signal. Examples of the optical device can include a camera/video device, a telescope device, a microscope device, an interferometer device, a photometer device, a polarimeter device, a spectrometer device, a reflectometer device, an autocollimator device, a lensmeter device, etc., and the present embodiment can be applied to an optical device that can include a lens assembly having a liquid lens module (100).

In addition, the optical device can be implemented as a portable device such as a smart phone, a laptop computer, or a tablet computer. The optical device can include a camera module having a liquid lens module (100), a display unit (not shown) for outputting an image, a battery (not shown) for supplying power to the camera module, and a main body housing in which the camera module, the display unit, and the battery are mounted. The optical device can further include a communication module capable of communicating with other devices, and a memory unit capable of storing data. The communication module and the memory unit can also be mounted in the main body housing.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

Claims (7)

A first liquid lens comprising a first cavity and a plurality of first individual electrodes spaced apart from each other with a first boundary portion interposed therebetween, the first boundary portion including a plurality of boundary portions; and
A second liquid lens comprising a second cavity arranged to overlap the first cavity and the optical axis direction, and a plurality of second individual electrodes arranged to be spaced apart from each other with a second boundary portion including a plurality of boundary portions therebetween,
The first boundary portion and the second boundary portion are arranged so as not to overlap each other in a direction parallel to the optical axis,
A liquid lens module in which the minimum angle formed on a plane by a first virtual line connecting the first boundary portion from the optical axis passing through the center of the first cavity and the center of the second cavity and a second virtual line connecting the second boundary portion from the optical axis is equal to or less than Δθ, which is expressed as follows.

(Here, M represents the number of the first individual electrodes, and N represents the number of the second individual electrodes.) delete In the first paragraph,
Each of the plurality of first individual electrodes and the second boundary overlap each other in the direction parallel to the optical axis,
A liquid lens module wherein each of the plurality of second individual electrodes and the first boundary overlap each other in the direction parallel to the optical axis. In the first paragraph,
The above first liquid lens
A first lower plate including a first cavity in which a conductive liquid and a non-conductive liquid are placed;
A second lower plate positioned above and below the first lower plate; and
A third lower plate is disposed above and below the first lower plate,
The above second liquid lens
A first upper plate including a second cavity in which a conductive liquid and a non-conductive liquid are placed;
A second upper plate positioned above and below the first upper plate; and
A liquid lens module comprising a third upper plate positioned at one of the other of above and below the first upper plate. In the fourth paragraph, a liquid lens module in which one of the second and third lower plates and one of the second and third upper plates face each other and are integral with each other. In the fourth paragraph,
The first cavity includes first and second openings formed above and below the first lower plate, respectively,
The second cavity includes third and fourth openings formed above and below the first upper plate, respectively;
The sizes of the larger opening among the first and second openings and the larger opening among the third and fourth openings are the same,
A liquid lens module wherein the smaller of the first and second openings and the smaller of the third and fourth openings have the same size. In the first paragraph,
A liquid lens module wherein the first boundary portion is arranged in a direction corresponding to a side of the first liquid lens, and the second boundary portion is arranged in a direction corresponding to a corner of the second liquid lens.

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