KR102714149B1 - Liquid lens module, camera module, and optical apparatus - Google Patents

Abstract

A camera module according to one embodiment of the present invention may include a first liquid lens including a conductive liquid and a non-conductive liquid forming a first interface; a second liquid lens including a conductive liquid and a non-conductive liquid forming a second interface; and a control circuit supplying first to fourth individual voltages to the first liquid lens and the second liquid lens for controlling the first interface and the second interface.

Description

LIQUID LENS MODULE, CAMERA MODULE, AND OPTICAL APPARATUS

The present invention relates to a liquid lens module, a camera module and an optical device. More specifically, the present invention relates to a liquid lens module, a camera module and an optical device capable of adjusting a focal length using electrical energy.

Users of portable devices want optical devices that have high resolution, are small in size, and have various shooting functions (such as auto-focusing (AF) function, optical image stabilization (OIS) function, etc.). These shooting functions can be implemented by combining multiple lenses and directly moving the lenses, but increasing the number of lenses can increase the size of the optical device.

Autofocus and image stabilization functions are performed by moving or tilting multiple lens modules fixed to a lens holder and having their optical axes aligned in the optical axis or in the direction perpendicular to the optical axis, and a separate lens driving device is used to drive the lens modules. However, the lens driving device consumes high power and increases the overall thickness.

Therefore, research is being conducted on a liquid lens that performs autofocus and image stabilization functions by electrically controlling the curvature of the interface between two liquids.

The present invention provides a liquid lens module, a camera module, and an optical device capable of improving OIS performance by vertically arranging a plurality of liquid lenses.

The technical problems to be achieved in the present invention 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.

According to one embodiment of the present invention, a camera module includes a first liquid lens including a conductive liquid and a non-conductive liquid forming a first interface; a second liquid lens including a conductive liquid and a non-conductive liquid forming a second interface; and a control circuit supplying first to fourth individual voltages to the first liquid lens and the second liquid lens for controlling the first interface and the second interface, wherein each of the first liquid lens and the second liquid lens may include a first plate including a cavity in which the conductive liquid and the non-conductive liquid are disposed; an electrode portion including a first electrode and a second electrode disposed on the first plate and electrically connected to an external power source to change an interface between the conductive liquid and the non-conductive liquid; and an insulating portion disposed on the electrode portion and blocking contact with the non-conductive liquid.

In an embodiment, the control circuit supplies a common voltage to the first liquid lens and the second liquid lens for controlling the first interface and the second interface, and a common electrode sector for receiving the common voltage included in the second electrode of the first liquid lens and a common electrode sector for receiving the common voltage included in the second electrode of the second liquid lens may be electrically connected to each other.

According to an embodiment, the device may further include a second connecting substrate electrically connected to the common electrode sectors of the first liquid lens and the second liquid lens and the control circuit to transmit a common voltage for controlling the first interface and the second interface.

In some embodiments, the second connecting substrate may be a conductive metal plate.

According to an embodiment, the first electrode of the first liquid lens includes first to fourth electrode sectors for receiving the first to fourth individual voltages, the first electrode of the second liquid lens includes fifth to eighth electrode sectors for receiving the first to fourth individual voltages, and the first to fourth electrode sectors and the fifth to eighth electrode sectors can be arranged to be aligned so that the positions of corresponding electrode sectors match each other.

According to an embodiment, the control circuit can supply the first to fourth individual voltages to the first to fourth electrode sectors, respectively, and supply the first to fourth individual voltages to the fifth to eighth electrode sectors, respectively.

According to an embodiment, the control circuit may supply the first to fourth individual voltages to the first to fourth electrode sectors, respectively, and supply the first to fourth individual voltages to the seventh electrode sector, the eighth electrode sector, the fifth electrode sector, and the sixth electrode sector, respectively.

According to an embodiment, the control circuit may supply the first to fourth individual voltages to the first to fourth electrode sectors, respectively, and may not supply the first to fourth individual voltages to the fifth to eighth electrode sectors.

According to an embodiment, the device may further include a first connecting substrate electrically connected to the first to fourth electrode sectors of the first liquid lens and the control circuit to transmit a voltage for controlling the first interface; and a third connecting substrate electrically connected to the fifth to eighth electrode sectors of the second liquid lens and the control circuit to transmit a voltage for controlling the second interface.

According to an embodiment, the first connecting substrate and the third connecting substrate may be FPCB.

A liquid lens module according to one embodiment of the present invention may include a first liquid lens including first to fourth electrode sectors receiving a voltage for controlling a first interface; and a second liquid lens including fifth to eighth electrode sectors receiving a voltage for controlling a second interface, wherein any one of the voltages applied to the first to fourth electrode sectors is identical to any one of the voltages applied to the fifth to eighth electrode sectors, and each of the first liquid lens and the second liquid lens may include: a first plate including a cavity in which the conductive liquid and the non-conductive liquid are disposed; an electrode portion including a first electrode and a second electrode disposed on the first plate and electrically connected to an external power source to change an interface between the conductive liquid and the non-conductive liquid; and an insulating portion disposed on the electrode portion and blocking contact with the non-conductive liquid.

According to an embodiment, the first to fourth electrode sectors and the fifth to eighth electrode sectors may be arranged so that the positions of the corresponding electrode sectors match each other.

According to an embodiment, the first electrode of the first liquid lens including the first to fourth electrode sectors may be disposed on an upper portion of the first liquid lens, and the first electrode of the second liquid lens including the fifth to eighth electrode sectors may be disposed on a lower portion of the second liquid lens.

According to an embodiment, the second electrode of the first liquid lens and the second electrode of the second liquid lens for receiving a common voltage for controlling the first interface and the second interface may be electrically connected to each other and disposed between the first liquid lens and the second liquid lens.

According to an embodiment, each of the voltages applied to the first to fourth electrode sectors may be equal to each of the voltages applied to the fifth to eighth electrode sectors.

According to an embodiment, each of the voltages applied to the first to fourth electrode sectors may be equal to the voltages applied to the seventh electrode sector, the eighth electrode sector, the fifth electrode sector, and the sixth electrode sector.

An optical device according to one embodiment of the present invention may include: the camera module; a display unit that outputs an image; a battery that supplies power to the camera module; and a housing that mounts the camera module, the display unit, and the battery.

The above aspects of the present invention are only some of the preferred embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by those skilled in the art based on the detailed description of the present invention to be described below.

The effects of the device according to the present invention are described as follows.

According to a liquid lens module, a camera module, and an optical device according to one embodiment of the present invention, a blur phenomenon that may occur in an image acquired by an image sensor during OIS operation can be eliminated.

Additionally, the OIS compensation angle for OIS operation can be doubled within the same time, which can reduce the OIS response time by half, thereby improving OIS performance.

The effects obtainable from the present invention 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 illustrates an example of a camera module according to one embodiment of the present invention.
Figure 2 illustrates an example of a lens assembly (22) included in a camera module.
Figure 3 is a block diagram briefly illustrating the camera module illustrated in Figure 1.
Figure 4 illustrates a liquid lens whose interface is adjusted in response to a driving voltage.
Figure 5 is a drawing to explain the phenomenon that occurs when the interface between a conductive liquid and a non-conductive liquid is adjusted for the OIS function.
FIG. 6 is a drawing for explaining the structure of a dual liquid lens according to one embodiment of the present invention.
FIG. 7 is a drawing showing a substrate for connecting the dual liquid lens and control circuit shown in FIG. 6.
FIG. 8 is a drawing for explaining a method of applying voltage to a liquid lens according to one embodiment of the present invention.
FIG. 9 is a drawing for explaining a method of applying voltage to a plurality of liquid lenses for each mode according to one embodiment of the present invention.
FIG. 10 is a drawing for explaining the effect according to the voltage application method of a plurality of mode-specific liquid lenses according to one embodiment of the present invention.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. The embodiments may have various modifications and may take various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the embodiments to a specific disclosed form, and it should be understood that it includes all modifications, equivalents, or substitutes included in the spirit and technical scope of the embodiments.

Although terms such as "first", "second", etc. may be used to describe various components, the components should not be limited by the terms. The terms are used for the purpose of distinguishing one component from another. In addition, terms specifically defined in consideration of the configuration and operation of the embodiment are only for the purpose of describing the embodiment, and do not limit the scope of the embodiment.

In the description of the embodiments, when it is described that each element is formed "on or under", "on or under" includes both cases where two elements are directly in contact with each other or where one or more other elements are formed by being disposed (indirectly) between the two elements. In addition, when expressed as "on or under", it can include the meaning of not only the upward direction but also the downward direction based on one element.

Additionally, relational terms such as “upper/upper/above” and “lower/lower/below” used hereinafter may be used to distinguish one entity or element from another, without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

Figure 1 illustrates an example of a camera module according to one embodiment of the present invention.

Referring to FIG. 1, the camera module (10) may include at least one of a liquid lens and a lens assembly (22) including a plurality of lenses, a control circuit (24), and an image sensor (26).

The liquid lens may include a liquid, a first plate, and an electrode portion. For example, the liquid lens may include one liquid lens or two liquid lenses (280, 290) as shown in FIG. 3, and the liquid included in the liquid lens may include a conductive liquid and a non-conductive liquid. In addition, at least one electrode portion may be disposed above or below the liquid lens, and may include, for example, an upper electrode above or a lower electrode below the liquid lens.

The first plate may include a cavity in which a conductive liquid and a non-conductive liquid are placed. The electrode portion may be electrically connected to an external power source so as to change an interface between the conductive liquid and the non-conductive liquid by applying a voltage. The liquid lens may further include an insulating layer placed on the electrode portion to block contact between at least one electrode and the non-conductive liquid.

A camera module to which a liquid lens is applied may include a control unit that controls a voltage applied to an electrode unit. The electrode unit may include a first electrode and a second electrode, and the first electrode and the second electrode may include at least one electrode sector. The first electrode and the second electrode may electromagnetically interact to change an interface between a conductive liquid and a non-conductive liquid.

The lens assembly (22) may include a plurality of lenses. The lens assembly (22) may be composed of a plurality of lenses including a liquid lens, and the liquid lens may have a focal length that can be adjusted in response to a driving voltage applied to the first electrode and the second electrode. The camera module (22) may further include a control circuit (24) for supplying a driving voltage to the liquid lens. The first electrode may be an individual electrode, and the second electrode may be a conductive metal plate and may be a common electrode. The voltage applied to the common electrode may be a reference potential of the driving voltage applied to the liquid lens.

The camera module (10) may include a plurality of circuits (24, 26) arranged on a single printed circuit board (PCB) and a lens assembly (22) including a plurality of lenses, but this is only one example and does not limit the scope of the invention. The configuration of the control circuit (24) may be designed differently depending on the specifications required for the optical device. In particular, in order to reduce the size of the operating voltage applied to the lens assembly (22), the control circuit (24) may be implemented as a single chip. Through this, the size of the optical device mounted on the portable device can be further reduced.

Figure 2 illustrates an example of a lens assembly (22) included in a camera module (10).

The camera module (10) may be included in an optical device. The optical device may include a housing that houses at least one of a camera module, a display unit, a communication module, a memory storage unit, and a battery.

Referring to FIG. 2, the lens assembly (22) may include a first lens unit (100), a second lens unit (200), a liquid lens (300), a holder (400), and a connecting unit (500).

The connecting portion (500) may be one or more. For example, when there is one connecting portion, a part of the connecting portion may be arranged on the upper or lower side of the liquid lens (300) and connected to the liquid lens (300), and when there are two connecting portions, there may be a first connecting portion connected to the upper side of the liquid lens (300) and a second connecting portion connected to the lower side of the liquid lens. The connecting portion may be a flexible printed circuit board (FPCB) or a metal plate made of a conductive material. One end of the connecting portion may be arranged below the lens assembly (22) and electrically connected to a substrate on which an image sensor (26) is mounted. The structure of the illustrated lens assembly (22) is only one example, and the structure of the lens assembly (22) may vary depending on the specifications required for the optical device. For example, in the illustrated example, the liquid lens (300) is positioned between the first lens unit (100) and the second lens unit (200), but in other examples, the first lens unit (100) or the second lens unit (200) may be omitted. In addition, the liquid lens (300) may be positioned above (in front) the first lens unit (100), or the liquid lens (300) may be positioned below the second lens unit (200). The liquid lens (300) includes a cavity defined by an opening area, and in the other example, the liquid lens (300) may be arranged so that the inclination direction of the cavity (310) is opposite. This may mean that, unlike FIG. 2, the opening area of the cavity (310) in the direction in which light is incident is narrower than the opening area in the opposite direction. When the liquid lens (300) is arranged so that the inclination direction of the cavity (310) is opposite, the arrangement of the entire or part of the configuration of the liquid lens (300), such as the electrode and the liquid, may be changed together depending on the inclination direction of the liquid lens (300), and only the inclination direction of the cavity may be changed and the remaining arrangement may not be changed.

The first lens unit (100) is arranged in front of the lens assembly (22) and is configured such that light is incident from the outside of the lens assembly (22). The first lens unit (100) may be composed of at least one lens, or two or more lenses may be aligned with respect to the central axis (PL) to form an optical system.

The first lens unit (100) and the second lens unit (200) can be mounted on the holder (400). At this time, a through hole is formed in the holder (400), and the first lens unit (100) and the second lens unit (200) can be placed in the through hole. In addition, a liquid lens (300) can be inserted into the space between the first lens unit (100) and the second lens unit (200) placed in the holder (400).

Meanwhile, the first lens unit (100) may include an exposure lens (110). The exposure lens (110) refers to a lens that can protrude outside the holder (400) and be exposed to the outside. In the case of the exposure lens (110), the lens surface may be damaged due to being exposed to the outside. If the lens surface is damaged, the image quality of the image captured by the camera module may deteriorate. In order to prevent or suppress surface damage of the exposure lens (110), a method such as arranging a cover glass, forming a coating layer, or configuring the exposure lens (100) with a wear-resistant material to prevent surface damage may be applied.

The second lens unit (200) is arranged behind the first lens unit (100) and the liquid lens (300), and light incident from the outside onto the first lens unit (100) can pass through the liquid lens unit (300) and enter the second lens unit (200). The second lens unit (200) can be arranged in a through hole formed in the holder (400) apart from the first lens unit (100).

Meanwhile, the second lens unit (200) may be composed of at least one lens, and when two or more lenses are included, they may be aligned with respect to the central axis (PL) to form an optical system.

The liquid lens (300) is arranged between the first lens unit (100) and the second lens unit (200), and can be inserted into the insertion port (410) of the holder (400). The liquid lens (300) can also be aligned with respect to the central axis (PL), similar to the first lens unit (100) and the second lens unit (200). One or at least two insertion ports (410) of the holder (400) can be formed on the side of the holder (400). The liquid lens (300) can be arranged in the insertion port (410). The liquid lens (300) can be arranged to protrude outward from the insertion port (410).

The liquid lens (300) may include a cavity (310). The cavity (310) is a portion through which light passing through the first lens unit (100) is transmitted, and may include liquid in at least a portion thereof. For example, the cavity (310) may include two types of liquids, that is, a conductive liquid and a non-conductive liquid (or an insulating liquid), and the conductive liquid and the non-conductive liquid may not mix with each other and may form a boundary. The boundary between the conductive liquid and the non-conductive liquid may be deformed by a driving voltage applied through the connecting portion (500), thereby changing the curvature and/or focal length of the liquid lens (300). When this deformation and change in curvature of the boundary are controlled, the liquid lens (300), the lens assembly (22) including the same, and the optical device may perform an auto-focusing (AF) function, an optical image stabilizer (OIS) function, etc.

Figure 3 is a block diagram briefly illustrating the camera module illustrated in Figure 1.

Referring to FIG. 3, a control circuit (210) and a lens assembly (250) included in a camera module (200) are illustrated, and each of the control circuit (210) and the lens assembly (250) may correspond to the control circuit (24) and the lens assembly (22) of FIG. 1.

The control circuit (210) is configured to perform AF function and OIS function and can control liquid lenses (280, 290) included in the lens assembly (250) using a user's request or detection result (e.g., movement signal of a gyro sensor (225)).

The control circuit (210) may include a controller (230) and a voltage driver (235). The gyro sensor (225) may be an independent configuration that is not included in the control circuit (210), and the control circuit (210) may further include the gyro sensor (225). In addition, the control circuit (210) may further include a switching block (240).

The gyro sensor (225) can detect the angular velocity of movement in two directions, the yaw axis and the pitch axis, to compensate for the up-down and left-right shaking of the optical device (200). The gyro sensor (225) can generate a movement signal corresponding to the detected angular velocity and provide it to the controller (230).

The controller (230) can extract only the desired band by removing high-frequency noise components from a motion signal using a low pass filter (LPF) to implement the OIS function, calculate the amount of shake using the motion signal from which the noise has been removed, and calculate the driving voltage corresponding to the shape that the liquid lens (280) should have to compensate for the calculated amount of shake.

The controller (230) can receive information for the AF function (i.e., distance information to an object) from inside (e.g., an image sensor) or outside (e.g., a distance sensor) of the optical device or camera module (200), and can calculate a driving voltage corresponding to a shape that the liquid lens (280) should have according to a focal distance for focusing on the object through the distance information.

The controller (230) can store a driving voltage table that maps a driving voltage and a driving voltage code for causing the voltage driver (235) to generate the driving voltage, and can obtain a driving voltage code corresponding to the calculated driving voltage by referring to the driving voltage table.

The voltage driver (235) can generate an analog driving voltage corresponding to a digital driving voltage code provided from the controller (230) and provide the generated driving voltage to the lens assembly (250).

The voltage driver (235) may include a voltage booster for receiving a supply voltage (e.g., voltage supplied from a separate power circuit) and increasing the voltage level, a voltage stabilizer for stabilizing the output of the voltage booster, and a switching unit for selectively supplying the output of the voltage booster to a switching block (240).

Here, the switching unit may include a circuit configuration called an H Bridge. The high voltage output from the voltage booster is applied as the power voltage of the switching unit. The switching unit may selectively supply the applied power voltage and ground voltage to the switching block (240).

Here, each of the first liquid lens (280) and the second liquid lens (290) may include a first electrode including four electrode sectors and a second electrode including one electrode sector for driving, and the two ends of the liquid lens (280) may mean the first electrode and the second electrode. In addition, the two ends of the liquid lens (280) may mean any one of the four electrode sectors of the first electrode and one electrode sector of the second electrode.

A pulse-shaped voltage having a preset width may be applied to each electrode sector of the liquid lens (280), and the driving voltage applied to the liquid lens (280) is an average value (or RMS (Root Mean Square) value) of the difference between the voltages applied to each of the first electrode and the second electrode within the operation cycle. Here, the voltage applied to each of the electrode sectors of the first electrode may be defined as an individual voltage, and the voltage applied to the electrode sector of the second electrode may be defined as a common voltage.

That is, in order for the voltage driver (235) to control the driving voltage applied to the liquid lens (280) according to the digital driving voltage code provided from the controller (230), the voltage booster controls the increasing voltage level, and the switching unit controls the phase of the pulse voltage applied to the common electrode and the individual electrodes, thereby generating an analog driving voltage corresponding to the driving voltage code.

That is, the control circuit (210) can control the voltage applied to each of the first electrode and the second electrode.

Here, the voltages applied to the four electrode sectors of the first electrode are defined as the first to fourth individual voltages (IV1 to IV4), and the voltage applied to one electrode sector of the second electrode is defined as the common voltage (CV).

The switching block (240) can provide first to fourth individual voltages (IV1 to IV4), which are voltages applied to four electrode sectors of the first electrode according to the control of the controller (230), to each electrode sector of one of the first electrodes of the first liquid lens (280) and the second liquid lens (290). In addition, the switching block (240) can provide a common voltage (CV), which is a voltage applied to one electrode sector of the second electrode, to the electrode sector of the second electrode of the first liquid lens (280) and the second liquid lens (290).

The controller (230) may determine one of a plurality of modes based on a default setting, a user's request, or the judgment of the controller (230). The plurality of modes may be a normal mode, an image enhancement mode, or an OIS boost mode, but the scope of the present invention is not limited thereto.

The above general mode may mean a mode in which only one of the first liquid lens (280) or the second liquid lens (290) operates for the AF function or the OIS function.

The above image improvement mode may refer to a mode for preventing the optical axis of an optical signal passing through the first liquid lens (280) from being distorted in order to prevent a blur phenomenon from occurring in the image when using the OIS function.

The above OIS boost mode may refer to a mode that allows the desired OIS compensation angle to be obtained more quickly when using the OIS function.

The controller (230) can generate a switching control signal (SC) corresponding to the determined mode and transmit it to the switching block (240).

The switching block (240) may or may not provide each of the first to fourth individual voltages (IV1 to IV4) to one electrode sector of each of the first electrodes of the first liquid lens (280) and the second liquid lens (290) according to the switching control signal (SC). The switching block (240) may be implemented as a type of MUX for this function, but the scope of the present invention is not limited thereto.

The switching block (240) is illustrated as being included in the control circuit (210) in FIG. 3, but may be included in the driving voltage providing unit (270) of the liquid lens module (260) according to another embodiment.

The control circuit (210) may further include a connector (not shown) that performs a communication or interface function of the control circuit (210). For example, the connector may perform communication protocol conversion for communication between the control circuit (210) using an I²C (Inter-Integrated Circuit) communication method and the lens assembly (250) using a MIPI (Mobile Industry Processor Interface) communication method.

Additionally, the connector can receive power from an external source (e.g., a battery) to supply power necessary for the operation of the control circuit (210) and the lens assembly (250).

The lens assembly (250) may include a liquid lens module (260), and the liquid lens module (260) may include at least one of a driving voltage providing unit (270), a first liquid lens (280), and a second liquid lens (290).

The driving voltage providing unit (270) can receive the driving voltage from the voltage driver (235) and provide the driving voltage to the first liquid lens (280) and the second liquid lens (290). The driving voltage providing unit (270) may include a voltage adjustment circuit or a noise removal circuit to compensate for loss due to terminal connection between the control circuit (210) and the lens assembly (250), or may bypass the output voltage.

The driving voltage providing unit (260) may be placed on an FPCB (Flexible Printed Circuit Board, or first substrate) that constitutes at least a portion of the connecting unit (500) of FIG. 2, but the scope of the present invention is not limited thereto.

As illustrated in FIG. 7, the driving voltage providing unit (260) may be included in at least one of a first connecting substrate (710) for providing first to fourth individual voltages (IV1 to IV4) to the first liquid lens (280), a second connecting substrate (720) for providing a common voltage (CV) to the first liquid lens (280) and the second liquid lens (290), and a third connecting substrate (730) for providing first to fourth individual voltages (IV1 to IV4) to the second liquid lens (290).

The first liquid lens (280) and/or the second liquid lens (290) can perform an AF function or an OIS function by changing the interface between the conductive liquid and the non-conductive liquid depending on the driving voltage.

FIG. 4 illustrates a liquid lens whose interface is adjusted in response to a driving voltage. Specifically, (a) illustrates a liquid lens (28) included in a lens assembly (250, see FIG. 3), and (b) illustrates an equivalent circuit of the liquid lens (28). Here, the liquid lens (28) means the first liquid lens (280) or the second liquid lens (290) of FIG. 3.

First, referring to (a), the liquid lens (28) whose interface is adjusted in response to the driving voltage can receive first to fourth individual voltages (IV1 to IV4) through the second electrode and a plurality of electrode sectors (L1, L2, L3, L4) which are arranged in four different directions with the same angular distance and constitute the first electrode. When the driving voltage is applied through the plurality of electrode sectors (L1, L2, L3, L4) which constitute the first electrode and the electrode sector (C0) which constitutes the second electrode, the boundary between the conductive liquid and the non-conductive liquid arranged in the cavity (310) can be deformed. The degree and shape of the deformation of the boundary between the conductive liquid and the non-conductive liquid can be controlled by the controller (230) to implement the AF function or the OIS function.

In addition, referring to (b), one side of the lens (28) can be described as a plurality of capacitors (30) that receive voltage from different electrode sectors (L1, L2, L3, L4) of the first electrode, and the other side is connected to the electrode sector (C0) of the second electrode and receives voltage.

Although this specification describes an example in which there are four different electrode sectors, the scope of the present invention is not limited thereto.

Figure 5 is a drawing to explain the phenomenon that occurs when the interface between a conductive liquid and a non-conductive liquid is adjusted for the OIS function.

Referring to FIG. 5, a conductive liquid (510) and a non-conductive liquid (520) are filled in a cavity (500) of a liquid lens (280 or 290). An interface formed by the conductive liquid (510) and the non-conductive liquid (520) can be controlled by a voltage transmitted to a first electrode and a voltage transmitted to a second electrode.

If the voltages delivered to each electrode sector of the first electrode are all the same, the conductive liquid (510) and the non-conductive liquid (520) can form an interface (IF).

However, if the voltages delivered to each electrode sector of the first electrode for the OIS function are not all the same, the conductive liquid (510) and the non-conductive liquid (520) may form an interface (IF') that is distorted in one direction.

At this time, the optical path (LW1) when the optical signal passes through the interface (IF) and the optical path (LW2) when it passes through the interface (IF') become different from each other, and the optical axis is distorted at a specific angle.

That is, when the OIS function is in operation, the optical axis may be misaligned due to distortion of the interface, and in this case, a blur phenomenon may occur in the image acquired by the image sensor (26).

FIG. 6 is a drawing for explaining the structure of a dual liquid lens according to one embodiment of the present invention.

Referring to FIG. 6, the first liquid lens (610) and the second liquid lens (620) included in the dual liquid lens may refer to the first liquid lens (280) and the second liquid lens (290) illustrated in FIG. 3, respectively.

Each of the first liquid lens (610) and the second liquid lens (620) may include a first cavity (615) and a second cavity (625) in which a conductive liquid and a non-conductive liquid are accommodated, respectively. Each of the first cavity (615) and the second cavity (625) may include an upper opening and a lower opening, and although the areas of the upper opening and the lower opening are illustrated as being the same in FIG. 6, the area of one of the upper opening and the lower opening may be larger than the area of the other.

For example, the area of the upper opening of the first cavity (615) may be larger or smaller than the area of the lower opening, and the size relationship between the area of the upper opening and the area of the lower opening of the second cavity (625) may be the same as or opposite to that of the first cavity (615).

Additionally, the area of the upper opening and the area of the lower opening of the first cavity (615) may be equal to the area of the upper opening and the area of the lower opening of the second cavity (625), respectively, or may be larger or smaller than the area of the upper opening and the area of the lower opening of the second cavity (625).

And, the conductive liquid accommodated in the first cavity (615) may be positioned above or below the non-conductive liquid, and the upper-lower relationship between the conductive liquid and the non-conductive liquid accommodated in the second cavity (625) may be the same as that of the first cavity (615) or may be the opposite.

The total areas of the first liquid lens (610) and the second liquid lens (620) may be different from each other, or they may have the same area to facilitate alignment between the first cavity (615) and the second cavity (625).

FIG. 6 illustrates a first liquid lens (610) and a second liquid lens (620), together with a first electrode (630) of the first liquid lens (610), a second electrode (640) of the first liquid lens (610) and the second liquid lens (620), and a first electrode (650) of the second liquid lens (620).

The first electrode (630, 650) and the second electrode (640) are illustrated as separate substrates, but this is only for explaining the arrangement of the electrodes, and in reality, they may be patterned and arranged on the upper or lower side of the first liquid lens (610) or the second liquid lens (620).

The first electrode (630) of the first liquid lens (610) may include a plurality of electrode sectors (L1, L2, L3, L4) arranged in four different directions with the same angular distance to constitute the first electrode (630). The first electrode (630) may be arranged on the upper portion of the first liquid lens (610). The plurality of electrode sectors (L1, L2, L3, L4) are arranged counterclockwise with respect to the first electrode sector (L1), but the scope of the present invention is not limited thereto.

The second electrode (640) of the first liquid lens (610) and the second liquid lens (620) may include one electrode sector (C0). The second electrode (640) may be arranged at the lower portion of the first liquid lens (610) and the upper portion of the second liquid lens (620). That is, the first liquid lens (610) and the second liquid lens (620) may share the second electrode (640) with each other through the second connecting substrate (720) of FIG. 7.

The first electrode (650) of the second liquid lens (620) may include a plurality of electrode sectors (L5, L6, L7, L8) arranged in four different directions with the same angular distance to form the first electrode (650). The first electrode (650) may be arranged at the bottom of the second liquid lens (620). The plurality of electrode sectors (L5, L6, L7, L8) are arranged in a counterclockwise direction with respect to the fifth electrode sector (L5), but the scope of the present invention is not limited thereto.

As illustrated in FIG. 6, the positions of each of the plurality of electrode sectors (L1, L2, L3, L4) constituting the first electrode (630) and each of the plurality of electrode sectors (L5, L6, L7, L8) constituting the second electrode (650) can be aligned and arranged to match each corresponding electrode sector (for example, L1 and L5).

FIG. 7 is a drawing showing a substrate for connecting the dual liquid lens and control circuit shown in FIG. 6.

Referring to FIG. 7, a first connection substrate (710) for providing first to fourth individual voltages (IV1 to IV4) to the first liquid lens (280), a second connection substrate (720) for providing a common voltage (CV) to the first liquid lens (280) and the second liquid lens (290), and a third connection substrate (730) for providing first to fourth individual voltages (IV1 to IV4) to the second liquid lens (290) are illustrated.

The first connecting substrate (710) is electrically connected to the first electrode (630) of FIG. 6 and electrically connected to the switching block (240) of the control circuit (210) of FIG. 3 so as to transmit the first to fourth individual voltages (IV1 to IV4) to the first electrode (630).

Specifically, the first connecting board (710) may include an upper first terminal (A), an upper second terminal (B), an upper third terminal (C), an upper fourth terminal (D) arranged counterclockwise, and a lower first terminal (A'), a lower second terminal (B'), a lower third terminal (C'), and a lower fourth terminal (D') electrically connected to each of the upper first terminal (A), the upper second terminal (B), the upper third terminal (C), and the upper fourth terminal (D).

Here, the first connecting substrate (710) can be divided into an upper substrate on which an upper first terminal (A), an upper second terminal (B), an upper third terminal (C), and an upper fourth terminal (D) are arranged, and a lower substrate on which a lower first terminal (A'), a lower second terminal (B'), a lower third terminal (C'), and a lower fourth terminal (D') are arranged. The first connecting substrate (710) can be implemented as an FPCB and can be included in the connecting portion (500) of FIG. 2. The first connecting substrate (710) can be bent along the boundary between the upper substrate and the lower substrate of the first connecting substrate (710) and mounted in the lens assembly (22).

The upper first terminal (A), the upper second terminal (B), the upper third terminal (C), and the upper fourth terminal (D) may be electrically connected to the first electrode sector (L1), the second electrode sector (L2), the third electrode sector (L3), and the fourth electrode sector (L4), respectively. In addition, the lower first terminal (A'), the lower second terminal (B'), the lower third terminal (C'), and the lower fourth terminal (D') may be electrically connected to the switching block (240).

The second connecting substrate (720) is electrically connected to the second electrode (640) of FIG. 6 and electrically connected to the switching block (240) of the control circuit (210) of FIG. 3 so as to transmit a common voltage (CV) to the second electrode (640).

Specifically, the second connecting board (720) may include an upper common terminal (COM) and a lower common terminal (COM') electrically connected to the upper common terminal (COM).

Here, the second connecting board (720) can be divided into an upper board having an upper common terminal (COM) arranged and a lower board having a lower common terminal (COM') arranged. The second connecting board (720) can be implemented as an FPCB and can be included in the connecting portion (500) of FIG. 2. The second connecting board (720) can be bent along the boundary between the upper board and the lower board of the second connecting board (720) and mounted in the lens assembly (22). According to another embodiment, the second connecting board (720) can also be implemented as a conductive metal plate in which the upper common terminal (COM) and the lower common terminal (COM') are integrally formed.

The upper common terminal (COM) can be electrically connected to one electrode sector (C0) of the second electrode (640). Additionally, the lower common terminal (COM') can be electrically connected to the switching block (240).

The third connecting substrate (730) is electrically connected to the first electrode (650) of FIG. 6 and electrically connected to the switching block (240) of the control circuit (210) of FIG. 3 so as to transmit the first to fourth individual voltages (IV1 to IV4) to the first electrode (650).

Specifically, the third connecting board (730) may include an upper fifth terminal (E), an upper sixth terminal (F), an upper seventh terminal (G), an upper eighth terminal (H) arranged counterclockwise, and a lower fifth terminal (E'), a lower sixth terminal (F'), a lower seventh terminal (G'), and a lower eighth terminal (H') electrically connected to each of the upper fifth terminal (E), the upper sixth terminal (F), the upper seventh terminal (G), and the upper eighth terminal (H).

Here, the third connecting board (730) can be divided into an upper board on which an upper fifth terminal (E), an upper sixth terminal (F), an upper seventh terminal (G), and an upper eighth terminal (H) are arranged, and a lower board on which a lower fifth terminal (E'), a lower sixth terminal (F'), a lower seventh terminal (G'), and a lower eighth terminal (H') are arranged. The third connecting board (730) can be implemented as an FPCB and can be included in the connecting portion (500) of FIG. 2. The third connecting board (730) can be bent along the boundary between the upper board and the lower board of the third connecting board (730) and mounted in the lens assembly (22).

The upper fifth terminal (E), the upper sixth terminal (F), the upper seventh terminal (G), and the upper eighth terminal (H) may be electrically connected to the fifth electrode sector (L5), the sixth electrode sector (L6), the seventh electrode sector (L7), and the eighth electrode sector (L8), respectively. In addition, the lower fifth terminal (E'), the lower sixth terminal (F'), the lower seventh terminal (G'), and the lower eighth terminal (H') may be electrically connected to the switching block (240).

FIG. 8 is a drawing for explaining a method for applying voltage to a liquid lens according to one embodiment of the present invention. FIG. 9 is a drawing for explaining a method for applying voltage to a plurality of liquid lenses for each mode according to one embodiment of the present invention. FIG. 10 is a drawing for explaining an effect according to a method for applying voltage to a plurality of liquid lenses for each mode according to one embodiment of the present invention.

Referring to FIG. 8, the voltage driver (810), switching block (820), first liquid lens (830), and second liquid lens (840) illustrated in FIG. 8 may correspond to the voltage driver (235), switching block (240), first liquid lens (280), and second liquid lens (290) of FIG. 3, respectively.

The switching block (820) receives first to fourth individual voltages (IV1 to IV4) and a common voltage (CV) from the voltage driver (810), and can provide a driving voltage to the first liquid lens (830) and the second liquid lens (840) according to a switching control signal (SC) of the controller (230).

As described above, the first liquid lens (830) can receive a voltage for controlling the first interface (IF1) formed by the conductive liquid and the non-conductive liquid included in the first liquid lens (830) through the first to fourth electrode sectors (L1 to L4) and the electrode sector (C0, hereinafter referred to as the “common electrode sector”) of the second electrode.

Similarly, the second liquid lens (840) can receive a voltage for controlling the second interface (IF2) formed by the conductive liquid and the non-conductive liquid included in the second liquid lens (840) through the fifth to eighth electrode sectors (L5 to L8) and the common electrode sector (C0).

The switching block (820) can transmit first to fourth individual voltages (IV1 to IV4) to each of the first to fourth electrode sectors (L1 to L4) and transmit a common voltage (CV) to the common electrode sector (C0) regardless of the switching control signal (SC).

However, the switching block (820) controls the first to fourth individual voltages (IV1 to IV4) according to the switching control signal (SC). The fifth to eighth electrode sectors (L5 to L8) can be supplied differently for each mode.

Although this specification describes three modes as shown in Fig. 9, the scope of the present invention is not limited thereto.

Referring to FIG. 9, the switching control signal (SC) can indicate any one of the image enhancement mode, OIS boost mode, and normal mode described in FIG. 3.

Fig. 9 (a) shows a voltage application method to the second liquid lens (840) in image enhancement mode.

The switching block (820) controls the first to fourth individual voltages (IV1 to IV4) according to a switching control signal (SC) indicating the image enhancement mode. It can be transmitted to each of the fifth to eighth electrode sectors (L5 to L8).

This means that, as can be seen in (a) of FIG. 9, the voltage applied to the first to fourth electrode sectors (L1 to L4) of the first liquid lens (830) is the same as the voltage applied to the fifth to eighth electrode sectors (L5 to L8) of the second liquid lens (840), respectively. That is, since the first to fourth electrode sectors (L1 to L4) and the fifth to eighth electrode sectors (L5 to L8) are aligned and arranged so that the positions of the corresponding electrode sectors match each other, the first interface (IF1) of the first liquid lens (830) and the second interface (IF2) of the second liquid lens (840) can have the same shape.

Referring to (a) of Fig. 10, an optical signal passing through the first interface (IF1) of the first liquid lens (830) may cause a blur phenomenon as the optical axis is misaligned. However, since a second interface (IF2) having the same shape as the first interface (IF1) exists, an optical signal passing through the first interface (IF1) of the first liquid lens (830) can be corrected to have the original optical axis while passing through the second interface (IF2) of the second liquid lens (840).

Therefore, it is possible to eliminate a blur phenomenon that may occur in an image acquired by the image sensor (26) during OIS operation.

Fig. 9 (b) shows a voltage application method to the second liquid lens (840) in OIS boost mode.

The switching block (820) supplies the first to fourth individual voltages (IV1 to IV4) to the seventh electrode sector (L7), the eighth electrode sector (L8), the fifth electrode sector (L5), and the sixth electrode sector (L6) according to a switching control signal (SC) indicating the OIS boost mode. Can be passed on to each person.

This means that, as can be seen in (b) of Fig. 9, the voltages applied to the first to fourth electrode sectors (L1 to L4) of the first liquid lens (830) are the same as the voltages applied to the seventh electrode sector (L7), the eighth electrode sector (L8), the fifth electrode sector (L5), and the sixth electrode sector (L6) of the second liquid lens (840), respectively. This means that the electrode sectors of the second liquid lens (840) are applied with the same voltage as the electrode sectors of the first liquid lens (830) located opposite each other with respect to the center of the lens. That is, since the first to fourth electrode sectors (L1 to L4) and the fifth to eighth electrode sectors (L5 to L8) are arranged so that the positions of the corresponding electrode sectors are identical, the first interface (IF1) of the first liquid lens (830) and the second interface (IF2) of the second liquid lens (840) can have opposite shapes.

Referring to (b) of FIG. 10, an optical signal passing through the first interface (IF1) of the first liquid lens (830) has an OIS compensation angle of the first angle (θ1) for OIS operation. However, since a second interface (IF2) having a shape opposite to that of the first interface (IF1) exists, an optical signal passing through the first interface (IF1) of the first liquid lens (830) can have an OIS compensation angle of the second angle (θ2), which is twice the first angle (θ1), while passing through the second interface (IF2) of the second liquid lens (840).

When the OIS is operated, a certain amount of time (hereinafter referred to as the 'OIS response time') is required for the liquid lens to be transformed into a desired interface after a driving voltage is applied to the liquid lens, and the OIS response speed or performance of the liquid lens is determined by this OIS response time. Typically, the OIS response time may be approximately 50 ms.

However, according to a camera module according to one embodiment of the present invention, the OIS compensation angle for OIS operation can be doubled within the same time, so that the OIS response time is reduced by half, thereby improving OIS performance.

Figure 9 (c) shows a voltage application method to the second liquid lens (840) in normal mode.

The switching block (820) applies the first to fourth individual voltages (IV1 to IV4) to the fifth to eighth electrode sectors (L5 to L8) according to a switching control signal (SC) indicating a normal mode. It may not be delivered to each one.

As can be seen in (c) of FIG. 9, by not transmitting the voltage applied to the first to fourth electrode sectors (L1 to L4) of the first liquid lens (830) to the second liquid lens (840), the diopter of the second interface (IF2) of the second liquid lens (840) can be maintained at 0. That is, only the first liquid lens (830) can be operated for the AF function or the OIS function, and the second liquid lens (840) can be not used. According to the normal mode, the power consumed by the liquid lens can be reduced.

According to another embodiment, by applying an average voltage of the voltages applied to the first to fourth electrode sectors (L1 to L4) to each of the fifth to eighth electrode sectors (L5 to L8) of the second liquid lens (840), it is possible to prevent performance degradation of the liquid lens due to unintended deformation of the second interface (IF2).

Below, the configuration of the camera module according to the present embodiment is described.

The camera module may include a lens assembly including a liquid lens, an infrared cut filter (not shown), a printed circuit board (not shown), an image sensor (not shown), and a control unit (not shown). However, in the camera module, at least one of the infrared cut filter and the control unit may be omitted or changed.

The infrared filter can block infrared light from entering the image sensor. The infrared filter can be placed between the lens assembly and the image sensor. The infrared filter can be an infrared absorption filter or an infrared reflection filter. In addition, the infrared filter can be formed by coating or depositing on one side of the liquid lens without being placed separately.

The upper surface of the printed circuit board and the liquid lens may be electrically connected. An image sensor may be arranged on the printed circuit board. The printed circuit board may be electrically connected to the image sensor. For example, a holder member may be arranged between the printed circuit board and the lens assembly. At this time, the holder member may accommodate an image sensor on the inside. The printed circuit board may supply power (current or voltage) to the liquid lens. Meanwhile, a control unit for controlling the liquid lens may be arranged on the printed circuit board.

Below, the configuration of the optical device according to the present embodiment is described.

The optical device may be any one of a mobile phone, a cellular phone, a smart phone, a portable smart device, a digital camera, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), and a navigation device. However, the type of the optical device is not limited thereto, and any device for taking images or photographs may be referred to as an optical device.

The optical device may include a main body (not shown), a camera module, and a display unit (not shown). However, in the optical device, one or more of the main body, the camera module, and the display unit may be omitted or changed.

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 can be implemented as new embodiments through this.

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 respects, 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 (11)

A first liquid lens comprising a conductive liquid and a non-conductive liquid forming a first interface;
A second liquid lens comprising a conductive liquid and a non-conductive liquid forming a second interface; and
A control circuit for supplying first to fourth individual voltages to the first liquid lens and the second liquid lens for controlling the first interface and the second interface,
Each of the first liquid lens and the second liquid lens,
A first plate including a cavity in which the conductive liquid and the non-conductive liquid are placed;
An electrode part including a first electrode and a second electrode arranged on the first plate and electrically connected to an external power source to change an interface between the conductive liquid and the non-conductive liquid; and
It includes an insulating part arranged on the above electrode part and blocks contact with the non-conductive liquid,
The first electrode of the first liquid lens comprises first to fourth electrode sectors for receiving the first to fourth individual voltages,
The first electrode of the second liquid lens includes fifth to eighth electrode sectors for receiving the first to fourth individual voltages,
A camera module in which the first to fourth electrode sectors and the fifth to eighth electrode sectors are aligned and arranged so that the positions of corresponding electrode sectors match each other. In the first paragraph,
The above control circuit supplies a common voltage to the first liquid lens and the second liquid lens for controlling the first interface and the second interface,
A camera module, wherein a common electrode sector for receiving the common voltage included in the second electrode of the first liquid lens and a common electrode sector for receiving the common voltage included in the second electrode of the second liquid lens are electrically connected to each other. In the second paragraph,
A camera module further comprising a second connecting substrate electrically connected to the common electrode sectors of the first liquid lens and the second liquid lens and the control circuit to transmit a common voltage for controlling the first interface and the second interface. delete In the first paragraph,
The above control circuit,
A camera module which supplies the first to fourth individual voltages to the first to fourth electrode sectors, respectively, and supplies the first to fourth individual voltages to the fifth to eighth electrode sectors, respectively. In the first paragraph,
The above control circuit,
A camera module that supplies the first to fourth individual voltages to the first to fourth electrode sectors, respectively, and supplies the first to fourth individual voltages to the seventh electrode sector, the eighth electrode sector, the fifth electrode sector, and the sixth electrode sector, respectively. In the first paragraph,
A first connecting substrate electrically connected to the first to fourth electrode sectors of the first liquid lens and the control circuit to transmit a voltage for controlling the first interface; and
A camera module further comprising a third connecting substrate electrically connected to the fifth to eighth electrode sectors of the second liquid lens and the control circuit to transmit a voltage for controlling the second interface. A first liquid lens comprising a conductive liquid and a non-conductive liquid forming a first interface, and first to fourth electrode sectors receiving a voltage for controlling the first interface; and
A second liquid lens comprising a conductive liquid and a non-conductive liquid forming a second interface, and including fifth to eighth electrode sectors receiving a voltage for controlling the second interface,
Any one of the voltages applied to the first to fourth electrode sectors is identical to any one of the voltages applied to the fifth to eighth electrode sectors,
Each of the first liquid lens and the second liquid lens,
A first plate including a cavity in which the conductive liquid and the non-conductive liquid are placed;
An electrode part including a first electrode and a second electrode arranged on the first plate and electrically connected to an external power source to change an interface between the conductive liquid and the non-conductive liquid; and
A liquid lens module comprising an insulating portion arranged on the electrode portion and blocking contact with the non-conductive liquid. In Article 8,
The first electrode of the first liquid lens including the first to fourth electrode sectors is arranged on the upper portion of the first liquid lens,
A liquid lens module, wherein the first electrode of the second liquid lens including the fifth to eighth electrode sectors is disposed at the lower portion of the second liquid lens. In Article 8,
A liquid lens module, wherein the second electrode of the first liquid lens and the second electrode of the second liquid lens are electrically connected to each other and are disposed between the first liquid lens and the second liquid lens to receive a common voltage for controlling the first interface and the second interface. Camera module of paragraph 1;
A display section that outputs images;
A battery that supplies power to the above camera module; and
An optical device comprising a housing housing the above camera module, a display unit, and a battery.