KR102720643B1 - Liquid lens - Google Patents

Abstract

A liquid lens according to an embodiment includes a first plate including a cavity in which a conductive liquid and a non-conductive liquid are placed, a first electrode disposed on the first plate, a second electrode disposed on the first plate and spaced apart from the first electrode, at least a portion of which is disposed on the cavity, an insulating layer disposed on the second electrode, and an optical member disposed between the conductive liquid and the non-conductive liquid.

Description

LIQUID LENS

The embodiment relates to a liquid lens.

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 that are fixed to a lens holder and aligned along the optical axis in the direction of the optical axis or perpendicular to the optical axis. For this purpose, a separate lens driving device that drives a lens assembly composed of multiple lenses is required. However, the lens driving device has high power consumption, and there is a problem that the overall size of the existing camera module increases because a cover glass must be added separately from the camera module to protect it. To solve this problem, research is being conducted on a liquid lens unit that performs auto focus and image stabilization functions by electrically controlling the curvature of the interface between two liquids.

In particular, as the liquid lens becomes larger in diameter, the wave front error (WFE) at the interface increases, and various studies are being conducted to resolve this.

The embodiment is to provide a liquid lens with reduced wavefront error.

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 according to one embodiment may include a first plate including a cavity in which a conductive liquid and a non-conductive liquid are placed; a first electrode disposed on the first plate; a second electrode disposed on the first plate and spaced apart from the first electrode, at least a portion of which is disposed on the cavity; an insulating layer disposed on the second electrode; and an optical member disposed between the conductive liquid and the non-conductive liquid.

For example, the refractive index of the optical member may have a value between the refractive index of the first liquid and the refractive index of the second liquid.

For example, the optical member may have a fluidity less than the fluidity of each of the first and second liquids.

For example, the optical member may have a light transmittance of 95% or greater.

For example, the wettability between the optical member and the second liquid may be greater than the wettability between the optical member and the first liquid.

For example, the material of the optical member may include silicate.

For example, at least a portion of the optical member may be spaced from the insulating layer at a reference diopter where the liquid lens becomes 0 diopter.

For example, the cavity may form a first opening on one side and a second opening on the other side, the size of the first opening may be larger than the size of the second opening, and the size of the optical member may be smaller than the first opening and larger than the second opening.

For example, the optical member may have a size smaller than the size of the interface between the first liquid and the second liquid at the reference diopter.

For example, the liquid lens may include a coating layer disposed on the insulating layer.

A liquid lens according to an embodiment can minimize the occurrence of wavefront errors even when the amount of change in driving voltage supplied to the liquid lens to perform an OIS function is large by placing an optical member having a lower fluidity than the fluidities of each of the first and second liquids between a first liquid and a second liquid, so that the OIS function can be faithfully performed without being affected by wavefront errors even at a large aperture.

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 cross-sectional view of a liquid lens module including a liquid lens according to an embodiment.
Figures 2a and 2b show partially enlarged cross-sectional views of an embodiment of part 'A' shown in Figure 1.
FIG. 3 is an example showing an optical member tilted in the liquid lens illustrated in FIG. 1.
Figure 4 is a graph showing the wavefront error by comparative examples and examples.
FIG. 5 is a conceptual diagram of a lens assembly including a liquid lens module according to an embodiment.
FIG. 6 illustrates a conceptual diagram of a camera module including a liquid lens module 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 according to an embodiment, a lens assembly including the lens, and a camera module including the assembly 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, 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.

FIG. 1 shows a cross-sectional view of a liquid lens module (100) including a liquid lens according to an embodiment.

A liquid lens module (100) may include a liquid lens, a first connection substrate (141) and/or a second connection substrate (144).

The liquid lens according to the embodiment may include different types of first and second liquids (LQ1, LQ2), first and second optical members (P1, P2, P3, P4), first and second electrodes (E1, E2), and an insulating layer (148).

The first and second liquids (LQ1, LQ2) are filled, accommodated, or placed in a cavity (CA:Cavity), and may include a first liquid (or conductive liquid) (LQ1) having conductivity and a second liquid (or insulating liquid or non-conductive liquid) (LQ2) having non-conductivity. The first liquid (LQ1) and the second liquid (LQ2) do not mix with each other, and an interface (BO) may be formed at a contact portion between the first and second liquids (LQ1, LQ2). For example, the first liquid (LQ1) may be placed on the second liquid (LQ2), but the embodiment is not limited thereto.

In a state where no driving voltage is applied from the outside to the liquid lens, the edges of the first and second liquids (LQ2, LQ1) can have a cross-sectional shape that is thinner than the center.

The first plate (P1) may include a cavity (CA). The inner side (i) of the first plate (P1) may define a side of the cavity (CA). At this time, the inner side (i) of the first plate (P1) may be inclined as illustrated in FIG. 1, but the embodiment is not limited thereto.

The first plate (P1) may include first and second openings (O1, O2) at the upper and lower ends. That is, the cavity (CA) may be defined as a region surrounded by the inner surface (i) of the first plate (P1), the first opening (O1), and the second opening (O2). The cavity (CA) forms the first opening (O1) on one side and the second opening (O2) on the other side, and the size of the first opening (O1) may be larger than the size of the second opening (O2).

Among the first and second apertures (O1, O2), the diameter of the wider aperture may vary depending on the field of view (FOV) required by the liquid lens or the role to be performed in the camera module including the liquid lens, which will be described later. According to an embodiment, the size (or area or width) of the first aperture (O1) may be larger than the size (or area or width) of the second aperture (O2). Here, the size of each of the first and second apertures (O1, O2) 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 first and second apertures (O1, O2) may mean a radius or diameter 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 first and second apertures (O1, O2) may have a shape of a hole having a circular cross-section.

The cavity (CA) is a portion through which light incident from the outside passes. Accordingly, the first plate (P1) forming the cavity (CA) may be made of a transparent material, or may be made of an opaque material or contain impurities so that light does not easily pass through.

Light may be incident through a first aperture (O1) that is wider than a second aperture (O2) in the cavity (CA) and may be emitted through the second aperture (O2), or may be incident through a second aperture (O2) that is narrower than the first aperture (O1) and may be emitted through the first aperture (O1). Hereinafter, light is described as being incident through the second aperture (O2) and then emitted through the first aperture (O1), but the following description may also be applied to a case where light is incident through the first aperture (O1) and then emitted through the second aperture (O2).

In addition, the second plate (P2) may be placed on one of the upper and lower portions of the first plate (P1), and the third plate (P3) may be placed on the other of the upper and lower portions of the first plate (P1). For example, as illustrated in FIG. 1, the second plate (P2) may be placed on the first plate (P1), and the third plate (P3) may be placed below the first plate (P1). In this case, the second plate (P2) may be placed on the upper surface of the first electrode (E1) and above the cavity (CA). The third plate (P3) may be placed on the lower surface of the second electrode (E2) and below the cavity (CA).

The second plate (P2) and the third plate (P3) may be positioned opposite each other with the first plate (P1) interposed therebetween. Additionally, at least one of the second plate (P2) or the third plate (P3) may be omitted.

At least one of the second or third plates (P2, P3) may have a rectangular planar shape. Each of the second and third plates (P2, P3) may be formed of a light-transmitting material as a region through which light passes. For example, each of the second and third plates (P2, P3) may be formed of glass, and may be formed of the same material for convenience of the process. In addition, the edge of each of the second and third plates (P2, P3) may have a rectangular shape, but is not necessarily limited thereto.

The second plate (P2) may have a configuration that allows incident light to proceed into the cavity (CA) of the first plate (P1). The third plate (P3) may have a configuration that allows light passing through the cavity (CA) of the first plate (P1) to be emitted. The second plate (P2) may be in direct contact with the first liquid (LQ1).

In addition, the actual effective lens area of the liquid lens may be narrower than the diameter of the first opening (O1) which is wider among the first and second openings (O1, O2) of the first plate (P1). First and second electrodes (E1, E2) may be respectively disposed on one surface and the other surface of the first plate (P1). The first electrode (E1) may be disposed spaced apart from the second electrode (E2) on at least a portion of one surface (e.g., the upper surface) of the first plate (P1). A part of the first electrode (E1) disposed on one surface of the first plate (P1) may be exposed to the first liquid (LQ1) having conductivity and may be in direct contact with the first liquid (LQ1). A plurality of second electrodes (E2) may be disposed on the other surface (e.g., the upper surface, the inner surface, and the lower surface) of the first plate (P1).

Additionally, the first electrode (E1) is disposed on the first plate (P1), and the second electrode (E2) is disposed on the first plate (P1) spaced apart from the first electrode (E1), and at least a portion of the second electrode (E2) may be disposed on the cavity (CA).

In addition, the first electrode (E1) may be one electrode (hereinafter referred to as a “common electrode”), and the second electrode (E2) may be n electrodes (hereinafter referred to as “individual electrodes”). Here, n may be a positive integer greater than or equal to 2.

For example, a plurality of second electrodes (E2) can be sequentially arranged clockwise (or counterclockwise) around the optical axis (LX).

Each of the first and second electrodes (E1, E2) can be made of a conductive material, for example, a metal.

Meanwhile, the insulating layer (148) may be arranged to cover a portion of the upper surface of the third plate (P3) in the lower region of the cavity (CA). That is, the insulating layer (148) may be arranged between the second liquid (LQ2) and the third plate (P3).

Additionally, an insulating layer (148) may be placed on the second electrode (E2).

In addition, the insulating layer (148) may be arranged to cover a part of the second electrode (E2) forming the side wall of the cavity (CA). In addition, the insulating layer (148) may be arranged to cover a part of the first electrode (E1) and the entire second electrode (E2) on the upper surface of the first plate (P1). In addition, the insulating layer (148) may be arranged to cover a part of the upper surface of the first plate (P1) exposed by the separation between the first electrode (E1) and the second electrode (E2).

In this way, the insulating layer (148) can block contact between the second electrode (E2) and the first liquid (LQ1), contact between the second electrode (E2) and the second liquid (LQ2), and contact between the third plate (P3) and the second liquid (LQ2).

An insulating layer (148) may cover one of the first and second electrodes (E1, E2) (e.g., the second electrode (E2)) and expose a portion of the other electrode (e.g., the first electrode (E1)) so that electrical energy may be applied to a first liquid (LQ1) having conductivity.

Meanwhile, the first connection substrate (141) can be electrically connected to an electrode pad formed on a main substrate (not shown) described later through a connection pad electrically connected to the first electrode (E1). The second connection substrate (144) can be electrically connected to an electrode pad formed on the main substrate through a connection pad electrically connected to each of a plurality of second electrodes (E2).

For example, the first connecting substrate (141) may be implemented as an FPCB or a single metal substrate (conductive metal plate), and each of the second connecting substrates (144) may be implemented as a flexible printed circuit board (FPCB), but the embodiment is not limited thereto.

Although not shown, the first connection substrate (141) and the first electrode (E1) can be brought into contact, coupled, and electrically connected by disposing a conductive epoxy between the first connection substrate (141) and the first electrode (E1). In addition, the second connection substrate (144) and the plurality of second electrodes (E2) can be brought into contact, coupled, and electrically connected by disposing a conductive epoxy between the second connection substrate (144) and the plurality of second electrodes (E2). The first connection substrate (141) and the first electrode (E1) may be implemented as separate elements or may be implemented as an integrated unit. In addition, the second connection substrate (144) and the plurality of second electrodes (E2) may be implemented as separate elements or may be implemented as an integrated unit.

The first connecting substrate (141) can transmit one voltage (hereinafter, referred to as a “common voltage”) to the liquid lens, and the second connecting substrate (144) can transmit four different voltages (hereinafter, referred to as “individual voltages”) to the liquid lens. 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. The individual voltages supplied through the second connecting substrate (144) may be applied to a plurality of second electrodes (E2) exposed at each corner of the liquid lens. That is, voltage may be supplied to the liquid lens through the first connecting substrate (141) and the second connecting substrate (144).

Meanwhile, the optical member (P4) of the liquid lens according to the embodiment can be placed between the first liquid (LQ1) and the second liquid (LQ2).

In one embodiment, the refractive index of the optical member (P4) can have a value between the refractive index of the first liquid (LQ1) and the refractive index of the second liquid (LQ2). This is to allow light incident from the second opening (O2) to be emitted through the first opening (O1) or light incident from the first opening (O1) to be emitted through the second opening (O2).

In another embodiment, the refractive index of the optical member (P4) may be the same as the refractive index of the first liquid (LQ1) or may be the same as the refractive index of the second liquid (LQ2). For example, when the second liquid (LQ2) is oil, the refractive index of the optical member (P4) may be the same as the refractive index of the oil (LQ2).

In addition, the optical member (P4) can have a light transmittance of 95% or more. Accordingly, light can pass through the cavity (CA) via the second liquid (LQ2), the optical member (P4), and the first liquid (LQ1) without being obstructed by the optical member (P4) or with minimal obstruction.

In addition, the optical member (P4) may be a plate in the shape of a plate, or may be in the form of a thin film or membrane. In addition, the optical member (P4) may be implemented with a rigid material or a flexible material.

Additionally, the material of the optical member (P4) may include silicate.

Figures 2a and 2b show partially enlarged cross-sectional views of an embodiment (A1, A2) of part ‘A’ illustrated in Figure 1.

Fig. 3 exemplarily shows an appearance in which the optical member (P4) is tilted in the liquid lens illustrated in Fig. 1. Except for the appearance in which the optical member (P4) is tilted, the liquid lens illustrated in Fig. 3 is identical to the liquid lens illustrated in Fig. 1, and thus the same reference numerals are used.

In addition, as illustrated in FIG. 1, the optical member (P4) may have a flat cross-sectional shape at a liquid lens reference diopter. Here, the reference diopter may mean ‘0’ diopter. The ‘0’ diopter may mean a state in which the interface (BO) between the first liquid (LQ1) and the second liquid (LQ2) is not tilted and is parallel to a direction perpendicular to the optical axis (LX) (for example, the x-axis and y-axis directions). A driving voltage may be supplied to the liquid lens to make the liquid lens into a ‘0’ diopter state.

Additionally, at least a portion of the optical member (P4) in the reference diopter may be positioned spaced apart from the insulating layer (148).

Alternatively, the end portion (P4E) of the optical member (P4) as shown in FIGS. 1 and 2b in the reference diopter may be placed in contact with the insulating layer (148) disposed on the inner surface (i) of the first plate (P1).

In addition, as illustrated in FIG. 2b, the liquid lens may further include a coating layer (150). The coating layer (150) may be disposed on the inner surface (i) of the first plate (P1). That is, the coating layer (150) may be disposed on a path that faces the optical member (P4) when tilted among the inner surfaces (i) of the first plate (P1) and may be disposed on the insulating layer (148).

If, as illustrated in FIG. 1, the end (P4E) of the optical member (P4) is arranged to be in contact with the insulating layer (148), the tilting of the optical member (P4) may be hindered by friction between the end (P4E) and the insulating layer (148) when the optical member (P4) starts to tilt or while being tilted. However, as illustrated in FIG. 2b, if the coating layer (150) is provided, the end (P4E) is in contact with the coating layer (150) instead of the insulating layer (148), so that the hindrance to the tilting of the optical member (P4) can be resolved. To this end, the coating layer (150) may be implemented with a material having a smaller frictional force with the end (P4E) than the insulating layer (148). For example, the coating layer (150) may include fluorine, but the embodiment is not limited thereto.

Alternatively, in the reference diopter, the end (P4E) of the optical member (P4) may be spaced apart from the inner surface (i) (or, the insulating layer (148)) by a certain distance (d1, d2) as illustrated in FIG. 2a or FIG. 3. That is, the first or second liquid (LQ1, LQ2) may be positioned between the end (P4E) of the optical member (P4) and the insulating layer (148) in the reference diopter. Accordingly, unlike as illustrated in FIG. 1 where the end (P4E) is in contact with the insulating layer (148), as illustrated in FIGS. 2a and 3, since the end (P4E) is not in contact with the insulating layer (148), no frictional force occurs between the end (P4E) and the insulating layer (148) when the optical member (P4) is tilted, and thus the coating layer (150) illustrated in FIG. 2b may be omitted.

In addition, the wettability (or, wettability) between the optical member (P4) and the second liquid (LQ2) may be greater than the wettability between the optical member (P4) and the first liquid (LQ1). Therefore, as illustrated in FIGS. 2A and 3 , the optical member (P4) may be disposed above the second liquid (LQ2) below the interface (BO) between the first liquid (LQ1) and the second liquid (LQ2).

Additionally, the size (or area or diameter) (X1) of the optical member (P4) may be smaller than the size of the first opening (O1) and larger than the size of the second opening (O2).

Additionally, the size (or area or diameter) (X1) of the optical member (P4) may be smaller than the size (or area or diameter) (X2) of the interface (BO) between the first liquid (LQ1) and the second liquid (LQ2) at the reference diopter.

When a driving voltage is applied to the first and second electrodes (E1, E2) through the first connecting substrate (141) and the second connecting substrate (144), the interface (BO) between the first liquid (LQ1) and the second liquid (LQ2) is deformed so that the interface (BO) of the liquid lens can be tilted. At this time, as illustrated in FIG. 3, when the interface (BO) is tilted, the optical member (P4) can also be tilted together. At this time, the amount of the second liquid (LQ2) can be adjusted so that the optical member (P4) does not ?K-tick to the upper surface of the insulating layer (148).

By changing the angle at which the interface (BO) and the optical member (P4) formed within the liquid lens are tilted in response to the driving voltage, the lens assembly, camera module, and optical device including the liquid lens according to the embodiment can perform an optical image stabilizer (OIS) function.

Hereinafter, liquid lenses are compared and explained through comparative examples and examples.

Figure 4 is a graph showing wavefront error (WFE) by comparative examples and embodiments, where the horizontal axis represents the change amount (ΔV) of the driving voltage (V) supplied to the liquid lens, and the vertical axis represents the wavefront error (WFE).

The liquid lens by the comparative example does not include an optical member (P4). Therefore, when the change amount (ΔV) of the driving voltage (V) supplied to the liquid lens by the comparative example to perform the OIS function is large, the wavefront error (WFE1) at the interface (BO) of the liquid lens may increase. This wavefront error (WFE1) may become more severe as the diameter of the liquid lens increases, for example, when the diameter of the second aperture (O2) is 3 mm or more.

However, in the case of the liquid lens according to the embodiment, the optical member (P4) is placed between the first liquid (LQ1) and the second liquid (LQ2). At this time, if the fluidity of the optical member (P4) is smaller than the fluidity of each of the first and second liquids (LQ1, LQ2), even if the amount of change (ΔV) of the driving voltage (V) supplied to the liquid lens to perform the OIS function is large, the occurrence of the wavefront error (WFE2) can be minimized and made smaller than in the comparative example.

Among the interfaces (BO) of the liquid lens, the region where the wavefront error (WFE) affects the OIS function is a region that overlaps the second aperture (O2) in a direction parallel to the optical axis (LX) (for example, the z-axis direction). Therefore, since the size (or area or diameter) (X1) of the optical member (P4) is larger than the size of the second aperture (O2), the liquid lens according to the embodiment can faithfully perform the OIS function without being affected by the wavefront error (WFE) even at a large diameter.

A liquid lens module including a liquid lens according to the above-described embodiment can be applied to various fields.

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

FIG. 5 shows an exploded view of a lens assembly (200) including a liquid lens module (100) according to an embodiment.

The lens assembly (200) illustrated in FIG. 5 may include at least one of a holder (210), a first lens unit (220), a liquid lens module (230), and a second lens unit (240). The liquid lens module (230) may be the liquid lens module (100) illustrated in FIGS. 1 to 3.

The first lens unit (220) is arranged on the upper side of the liquid lens module (230) and may be an area where light is incident from the outside of the lens assembly (200). That is, the first lens unit (220) may be arranged on the liquid lens module (230) within the holder (210). The first lens unit (220) may be implemented as one lens, or may be implemented as two or more lenses that are aligned based on a central axis to form an optical system. Here, the central axis may mean an optical axis (LX) of the optical system formed by the first lens unit (220), the liquid lens module (230), and the second lens unit (240), or may mean an axis parallel to the optical axis (LX). The optical axis (LX) may correspond to the optical axis of the image sensor (340) included in the camera module (300) described below. That is, the first lens unit (220), the liquid lens module (230), the second lens unit (240), and the image sensor (340) can be arranged and aligned along the optical axis (LX) through active alignment (AA).

The second lens unit (240) may be placed underneath the liquid lens module (230) inside the holder (210). The second lens unit (240) may be placed spaced apart from the first lens unit (220) in the optical axis direction (for example, the z-axis direction). The second lens unit (240) may be implemented as one lens, or may be implemented as two or more lenses aligned with respect to a central axis to form an optical system.

Light incident from the outside of the lens assembly (200) onto the first lens unit (220) may pass through the liquid lens module (230) and be incident onto the second lens unit (240). Unlike the liquid lens module (230), each of the first lens unit (220) and the second lens unit (240) is a solid lens and may be made of glass or plastic, but the embodiment is not limited to a specific material of each of the first lens unit (220) and the second lens unit (240). In addition, at least one of the first lens unit (220) or the second lens unit (240) may be omitted. In addition, unlike as illustrated in FIG. 5, the liquid lens module (230) may be placed above the first lens unit (220) or below the second lens unit (240).

The holder (210) serves to accommodate, mount, settle, contact, fix, temporarily fix, support, combine, or place the first lens unit (220), the liquid lens module (230), and the second lens unit (240). The first lens unit (220) and the second lens unit (240) are accommodated inside the holder (210), while some of the liquid lens modules (230) may be accommodated inside the holder (210) and the other may be arranged to protrude outside the holder (210). This is to electrically connect the first and second connection substrates (141, 144) of the liquid lens module (230) with the main substrate (350) described later in FIG. 6. Since the first and second connection substrates (141, 144) are connected to the main substrate (350), the liquid lens module (230) can receive a driving voltage for driving from the main substrate (350).

Hereinafter, a camera module (300) including a liquid lens module according to an embodiment will be described with reference to the attached drawings.

FIG. 6 shows an exploded view of a camera module (300) including a liquid lens module (100) according to an embodiment.

The camera module (300) illustrated in FIG. 6 may include a lens assembly (200), an image sensor (340), and a main board (350). Here, the lens assembly (200) corresponds to the lens assembly illustrated in FIG. 5, and therefore, the same reference numerals are used, and redundant descriptions are omitted.

The image sensor (340) is arranged between the main substrate (350) and the lens assembly (200), and can perform a function of converting light passing through the first lens unit (220), the liquid lens module (230), and the second lens unit (240) of the lens assembly (200) into image data. More specifically, the image sensor (340) can convert light into an analog signal through a pixel array including a plurality of pixels, and generate image data by synthesizing a digital signal corresponding to the analog signal.

The main substrate (350) is arranged at the bottom of the lens assembly (200) and may include a groove, circuit elements (not shown), a connection part (not shown) such as an FPCB, and a connector (not shown) in which the image sensor (340) can be mounted, settled, contacted, fixed, temporarily fixed, supported, coupled, or received. The main substrate (350) serves to apply a driving voltage to the individual electrodes (E2) and the common electrode (E1) of the liquid lens through the first and second connection substrates (141, 144).

The circuit elements of the main substrate (350) may constitute a control module that controls the liquid lens module (230) and the image sensor (340). The main substrate (350) may include a holder area where the holder (210) is placed and an element area where a plurality of circuit elements are placed.

The camera module (300) may further include a middle base (320). The middle base (320) may be arranged to surround the lower portion of the holder (210) illustrated in FIG. 5. The middle base (320) may be omitted as a member that exists to be gripped by a gripper when performing active alignment in the camera module (300) illustrated in FIG. 6.

The middle base (320) can be mounted on the main substrate (350) and spaced apart from the circuit elements (not shown) placed on the main substrate (350).

The camera module (300) may further include a sensor base and a filter (330). The filter may filter light corresponding to a specific wavelength range among light passing through the first lens unit (220), the liquid lens module (230), and the second lens unit (240). The filter may be an infrared (IR) blocking filter or an ultraviolet (UV) blocking filter, but the embodiment is not limited thereto. The filter may be placed on the image sensor (340). The filter may be placed inside the sensor base. For example, the filter may be placed or mounted on an internal groove or step of the sensor base.

The sensor base may be placed at the bottom of the middle base (320) and attached to the main substrate (350). The sensor base may surround the image sensor (340) and protect the image sensor (340) from external foreign substances or impact.

The camera module (300) may further include a cover (310). The cover (310) is arranged to surround the holder (210), the liquid lens module (230), and the middle base (320), so as to protect them (210, 230, 320) from external impact. The cover (310) may protect a plurality of lenses forming an optical system from external impact.

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, an optical device can be implemented using a camera module (300) including a lens assembly according to the above-described embodiment. 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.

In addition, the optical device may be implemented as a portable device such as a smart phone, a laptop computer, or a tablet computer. Such an optical device may include a camera module (300), a display unit (not shown) that outputs an image, a battery (not shown) that supplies power to the camera module (300), and a main body housing that mounts the camera module (300), the display unit, and the battery. The optical device may further include a communication module that can communicate with other devices, and a memory unit that can store data. The communication module and the memory unit may 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.

100: Liquid lens module 141: First connecting board
144: Second connecting board 148: Insulating layer
150: Coating layer

Claims (10)

A first plate including a cavity in which a first liquid having conductivity and a second liquid having non-conductivity are placed;
A first electrode disposed on the first plate;
A second electrode disposed on the first plate and spaced apart from the first electrode, at least a portion of which is disposed on the cavity;
An insulating layer disposed on the second electrode; and
Including an optical member disposed between the first liquid and the second liquid,
A liquid lens wherein at least a portion of said optical member is spaced from said insulating layer at a reference diopter at which the liquid lens becomes 0 diopter. A liquid lens in the first aspect, wherein the refractive index of the optical member has a value between the refractive index of the first liquid and the refractive index of the second liquid. In the first aspect, the optical member is a liquid lens having a fluidity lower than the fluidity of each of the first and second liquids. In the first paragraph, the optical member is a liquid lens having a light transmittance of 95% or more. A liquid lens in the first aspect, wherein the wettability between the optical member and the second liquid is greater than the wettability between the optical member and the first liquid. In the first paragraph, the material of the optical member is a liquid lens containing silicate. delete In the first paragraph, the cavity forms a first opening on one side and a second opening on the other side, and the size of the first opening is larger than the size of the second opening,
A liquid lens having a size of the optical member smaller than the first opening and larger than the second opening. In the first aspect, the optical member is a liquid lens having a size smaller than the size of the interface between the first liquid and the second liquid at the reference diopter. A liquid lens comprising a coating layer disposed on the insulating layer in the first aspect.

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