KR102357914B1 - Liquid lens, camera module and optical device/instrument including the same - Google Patents

Abstract

The present invention includes a liquid lens including a plurality of electrodes and a control circuit electrically connected to the plurality of electrodes to control the liquid lens, the plurality of electrodes being disposed on the liquid lens and including a common electrode including one sub-electrode; and an individual electrode disposed under the liquid lens and including a plurality of sub-electrodes, the control circuit comprising: a first voltage generator for outputting a first voltage; A camera that includes a second voltage generator that outputs a second voltage having a polarity opposite to the first voltage, and floats at least one of the individual electrodes while applying a first voltage, a second voltage, or a ground voltage to the common electrode module is provided.

Description

Liquid lens and camera module and optical device including the same

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

Users of portable devices want optical devices with high resolution, small size, and various shooting functions (eg, Auto-Focusing (AF) function, image stabilization or Optical Image Stabilizer (OIS) function, etc.) are doing Such a photographing function may be implemented through a method of directly moving a lens by combining a plurality of lenses, but if the number of lenses is increased, the size of the optical device may increase. Autofocus and image stabilization are performed by moving or tilting multiple lens modules fixed to the lens holder and aligned with the optical axis in the vertical direction of the optical axis or optical axis, and driving a separate lens to drive the lens module device is used. However, the lens driving device consumes high power, and in order to protect it, a cover glass must be added separately from the camera module, which increases the overall thickness. Therefore, research on a liquid lens that performs autofocus and image stabilization functions by electrically controlling the curvature of the interface between two liquids is being conducted.

The present invention uses a switching circuit and a negative voltage to generate a high driving voltage even with a low voltage by using a voltage for driving a lens in a camera module including a lens capable of adjusting a focal length using electrical energy. Therefore, it is possible to reduce the size of the integrated circuit for controlling the lens.

In addition, the present invention provides a method for driving a lens while alternately supplying a positive voltage and a negative voltage to a common electrode even when a low voltage is supplied to a plurality of terminals of a lens capable of adjusting a focal length It can generate high voltage.

In addition, the present invention floats some electrodes to control the driving voltage of the lens with adjustable focal length, thereby preventing the distortion of the interface that may occur when the voltage difference between the electrodes is turned on, resulting in more optical image stabilization (Optical Image Stablilization, OIS) can be performed more stably.

In addition, the present invention can control the driving voltage of the lens capable of adjusting the focal length more precisely than the pulses of the voltage provided to the common terminal and the plurality of terminals by using floating to control the lens control. The resolution and range can be increased.

In addition, the present invention is applied to a portable device, and a circuit for controlling a lens whose focal length is adjusted in response to a driving voltage applied between a common terminal and a plurality of terminals uses a ground voltage as a power supply voltage, It is possible to reduce the power consumption of the circuit and the camera module.

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 will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

A camera module according to an embodiment of the present invention includes a liquid lens including a plurality of electrodes; and a control circuit electrically connected to the plurality of electrodes to control the liquid lens, wherein the plurality of electrodes are disposed above the liquid lens and disposed below a common electrode including one sub-electrode and the liquid lens, an individual electrode including a plurality of sub-electrodes, wherein the control circuit comprises: a first voltage generator for outputting a first voltage; a second voltage generator outputting a second voltage having a polarity opposite to that of the first voltage, and floating at least one of the individual electrodes while applying the first voltage, the second voltage, or a ground voltage to the common electrode It can be floated.

In addition, the second voltage generator may include a charge pump that receives the first voltage from the first voltage generator and outputs the changed polarity.

Also, the first voltage may have an anode, and the second voltage generator may output the second voltage of a cathode having the same magnitude as the first voltage independently from the first voltage generator.

In addition, the switching element included in the at least one first switch may be commonly disposed on a plurality of sub-electrodes of the individual electrode, and the switching element included in the plurality of third switches may be configured for each sub-electrode of the individual electrode. They can be placed independently.

In addition, the sub-electrodes of at least two individual electrodes disposed at symmetrical positions with respect to the center of the liquid lens among the plurality of electrode sectors may float together for a preset time.

In addition, the entire sub-electrode of the individual electrode may be floated for a preset time.

A camera module according to another embodiment of the present invention includes a liquid lens including a plurality of electrodes; and a control circuit electrically connected to the plurality of electrodes to control the liquid lens, wherein the liquid lens comprises: a first plate including a cavity in which a conductive liquid and a non-conductive liquid are disposed; a first electrode disposed on the first plate; and a second electrode disposed under the first plate and including a sub-electrode, wherein the control circuit comprises: a first voltage generator for outputting a first voltage; a second voltage generator for outputting a second voltage having a polarity opposite to that of the first voltage; a first switch transmitting the first voltage or a ground voltage; a second switch transmitting the second voltage or the ground voltage; and a third switch connected to the first switch and the second switch and connected to the sub-electrode, wherein the third switch and the sub-electrode include at least four, and each of the four third switches comprises: The other two sub-electrodes may be connected to each of the four sub-electrodes and float when there is a difference in voltage applied to at least two of the four sub-electrodes.

A liquid lens control circuit according to another embodiment of the present invention is a circuit for controlling a liquid lens including a plurality of sub-electrodes, comprising: a first voltage generator for outputting a first voltage; a second voltage generator outputting a second voltage having a polarity opposite to that of the first voltage; a first switch transmitting the first voltage or a ground voltage; a second switch transmitting the second voltage or the ground voltage; and a plurality of third switches connected to the first switch and the second switch and connected to the plurality of sub-electrodes, wherein the plurality of third switches operate at least one of the plurality of sub-electrodes for a preset time. It can be floated.

A method of controlling a liquid lens according to another embodiment of the present invention is a method of controlling a liquid lens having a plurality of sub-electrodes including a first sub-electrode, wherein a first voltage is applied to the first sub-electrode and the first voltage is applied to the first sub-electrode. applying a second voltage having a polarity opposite to that of the ground voltage or a ground voltage; floating the first sub-electrode for a preset time; and applying the first voltage, the second voltage, or the ground voltage after the first sub-electrode floats for a preset time.

A camera module according to another embodiment of the present invention includes a liquid lens including a plurality of electrodes; and a control circuit electrically connected to the plurality of electrodes to control the liquid lens, wherein the liquid lens comprises: a first plate including a cavity in which a conductive liquid and a non-conductive liquid are disposed; a first electrode disposed on the first plate; and a second electrode disposed under the first plate and including a sub-electrode, wherein the control circuit comprises: a first voltage generator for outputting a first voltage; a second voltage generator for outputting a second voltage having a polarity opposite to that of the first voltage; a first switch transmitting the first voltage or a ground voltage; a second switch transmitting the second voltage or the ground voltage; and a third switch connected to the first switch, the second switch, and the sub-electrode, wherein the third switch and the sub-electrode are plural, and each of the plurality of third switches includes a plurality of the sub-electrodes. connected to each, and the control circuit may block at least one of the third switches for a preset time to block transmission of the first voltage, the second voltage, or the ground voltage to the at least one sub-electrode have.

In addition, the third switch includes a first switch element connected to the first switch and a second switch element connected to the second switch, and blocks the first switch element and the second switch element for a preset time. to prevent the first voltage, the second voltage, or the ground voltage from being transmitted to the at least one sub-electrode.

Aspects of the present invention are only some of the preferred embodiments of the present invention, and various embodiments in which the technical features of the present invention are reflected are detailed descriptions of the present invention that will be described below by those of ordinary skill in the art can be derived and understood based on

The effect on the device according to the present invention will be described as follows.

The present invention generates a driving voltage of a lens capable of adjusting a focal length by using a negative voltage, thereby making it possible to reduce the design of an element constituting an integrated circuit for controlling the lens.

In addition, the present invention can reduce the size of a circuit for generating a supply voltage for controlling a lens capable of adjusting the focal length and secure resolution and range even with a low-spec control circuit, thereby increasing productivity and lowering manufacturing cost. .

In addition, the present invention can perform stable optical image stabilization (OIS) even if there is a large difference in the driving voltage between electrodes in the process of controlling the movement of the interface within the liquid lens. Alternatively, the range of image correction may be increased and effective.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

1 illustrates a problem of a method of controlling a lens capable of adjusting a focal length using electrical energy.
2 illustrates an example of a camera module.
3 illustrates an example of a lens assembly included in a camera module.
4 illustrates a liquid lens whose focal length is adjusted in response to a driving voltage.
5 illustrates the interfacial motion of a liquid lens.
6 illustrates a first driving method of the liquid lens.
7 illustrates a second driving method of the liquid lens.
Fig. 8 describes a first example of the control circuit.
9 illustrates a second example of the control circuit.
Fig. 10 explains the structure of the liquid lens.
11 illustrates a third example of the control circuit.
12 illustrates a fourth example of the control circuit.
13 illustrates a fifth example of the control circuit.
Fig. 14 explains a first operation example of the control circuit shown in Fig. 13;
Fig. 15 explains a second operation example of the control circuit shown in Fig. 13;
16 illustrates a sixth example of the control circuit.
17 illustrates a seventh example of the control circuit.
18 illustrates an eighth example of the control circuit.
Fig. 19 explains a first operation example of the control circuit shown in Fig. 18;
Fig. 20 explains a second operation example of the control circuit shown in Fig. 18;

Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings. Since the embodiment may have various changes and may have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the embodiment to a specific disclosed form, and it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the embodiment.

Terms such as “first” and “second” may be used to describe various elements, but the elements should not be limited by the terms. These 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 describing the embodiment, and do not limit the scope of the embodiment.

In the description of the embodiment, in the case where it is described as being formed in "up (up)" or "below (on or under)" of each element, on (on or under) ) includes both elements in which two elements are in direct contact with each other or one or more other elements are disposed between the two elements indirectly. In addition, when expressed as “up (up)” or “down (on or under)”, the meaning of not only the upward direction but also the downward direction based on one element may be included.

Also, as used hereinafter, relational terms such as "upper/upper/above" and "lower/lower/below" etc. do not necessarily require or imply any physical or logical relationship or order between such entities or elements, It may be used to distinguish one entity or element from another entity or element.

1 illustrates a problem of a method of controlling a lens capable of adjusting a focal length using electrical energy. Specifically, (a) describes a control circuit for applying a driving voltage to the lens, and (b) describes a method for applying a driving voltage to the lens.

First, referring to (a), the control circuit receives the supply voltage VIN as input and increases the voltage level of the voltage booster 12, the voltage stabilizer 14 for stabilizing the output of the voltage booster 12, and the lens It may include a switching unit 16 for selectively supplying the output of the voltage booster 12 to (10).

Here, the switching unit 16 typically includes a circuit configuration called an H Bridge. The high voltage output from the voltage booster 12 is applied as a power supply voltage of the switching unit 16 . The switching unit 16 may selectively supply applied power voltage and ground voltage to both ends of the lens 10 .

Referring to FIG. 1B , a voltage in the form of a pulse having a preset width may be applied to both ends of the lens 10 , that is, the common terminal C0 and the individual terminal L1 . The driving voltage Vop applied to the lens 10 is the difference between the common terminal C0 and the individual terminal L1. Accordingly, when voltages of the same level are applied to the common terminal C0 and the individual terminals L1 with a time difference, it can be considered that the driving voltage Vop of 0V is applied. Referring to (b), when the same voltage is applied through the common terminal C0, the driving voltages Vop1 and Vop2 having different pulse widths as the times of the voltages applied to the individual terminals L1 vary. It can be seen that the lens 10 is applied to both ends.

Here, the operating voltage output from the voltage booster 12 has a level of about 70V. Therefore, the elements included in the switching unit 16 should also be able to be driven at a high voltage of 70V. Devices that must be driven at high voltage are difficult to miniaturize. Devices that can be driven at high voltage must satisfy characteristics such as breakdown voltage, specific on-resistance, safe operating area (SOA), and maximum forward voltage. . If a device operating at a high voltage is made too small, devices such as a transistor may not perform functions such as switching and amplification. For this reason, it is difficult to miniaturize the control circuit for supplying the driving voltage of the lens 10 , and productivity may decrease and thus the cost may increase.

2 illustrates an example of a camera module.

As shown, the camera module includes a lens assembly 22 including a plurality of lenses including a first lens whose focal length is adjusted in response to a driving voltage applied between a common terminal and a plurality of individual terminals, and a first It may include a control circuit 24 for supplying a driving voltage to the lens, and an image sensor 26 arranged in the lens assembly 22 and converting light transmitted through the lens assembly 22 into an electrical signal.

Referring to FIG. 2 , the camera module may include a plurality of circuits 24 and 26 formed on one printed circuit board (PCB) and a lens assembly 22 including a plurality of lenses, but this is one example. It does not limit the scope of the invention only. The configuration of the control circuit 24 may be designed differently according to specifications required for the camera module. In particular, when the level of the operating voltage applied to the lens assembly 22 is reduced, the control circuit 24 may be implemented as a single chip. Through this, the size of the camera module mounted on the portable device can be further reduced.

3 illustrates an example of the lens assembly 22 included in the camera module.

As shown, the lens assembly 22 may include a first lens unit 100 , a second lens unit 200 , a liquid lens unit 300 , a lens housing 400 , and a connection end 500 . . The illustrated structure of the lens assembly 22 is only one example, and the structure of the lens assembly 22 may vary according to specifications required for the camera module. For example, in the illustrated example, the liquid lens unit 300 is positioned between the first lens unit 100 and the second lens unit 200 , but in another example, the liquid lens unit 300 includes the first lens unit ( 100) may be located above (front).

Referring to FIG. 3 , the first lens unit 100 is disposed in front of the lens assembly, and is a portion on which light is incident from the outside of the lens assembly. The first lens unit 100 may be provided as 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 may be mounted on the lens housing 400 . In this case, a through hole may be formed in the lens housing 400 , and the first lens unit 100 and the second lens unit 200 may be disposed in the through hole. In addition, the liquid lens unit 300 may be inserted into a space between the first lens unit 100 and the second lens unit 200 in the lens housing 400 .

Meanwhile, the first lens unit 100 may include an exposure lens 110 . The exposure lens 110 refers to a lens that protrudes to the outside of the lens housing 400 and can be exposed to the outside. In the case of the exposure lens 110, the lens surface may be damaged due to exposure to the outside. If the lens surface is damaged, the image quality of the image taken by the camera module may be deteriorated. In order to prevent or suppress damage to the surface of the exposure lens 110 , a method of disposing a cover glass or forming a coating layer or configuring the exposure lens 100 with a wear-resistant material to prevent surface damage may be applied. Action may be required.

The second lens unit 200 is disposed behind the first lens unit 100 and the liquid lens unit 300 , and light incident to the first lens unit 100 from the outside passes through the liquid lens unit 300 . Thus, it can be incident to the second lens unit 200 . The second lens unit 200 may be spaced apart from the first lens unit 100 and disposed in a through hole formed in the lens housing 400 .

Meanwhile, the second lens unit 200 may be provided with at least one lens, and when two or more lenses are included, the optical system may be formed by aligning the second lens unit 200 with respect to the central axis PL.

The liquid lens unit 300 is disposed between the first lens unit 100 and the second lens unit 200 , and may be inserted into the insertion hole 410 of the lens housing 400 . The liquid lens unit 300 may also be aligned with the central axis PL like the first lens unit 100 and the second lens unit 200 .

The liquid lens unit 300 may include a lens region 310 . The lens region 310 is a portion through which the light passing through the first lens unit 100 transmits, and at least a portion thereof may include a liquid. For example, the lens region 310 may include two types, namely, a conductive liquid and a non-conductive liquid, and the conductive liquid and the non-conductive liquid may form an interface without being mixed with each other. The interface between the conductive liquid and the non-conductive liquid is deformed by the driving voltage applied through the connection terminal 500 , so that the curvature and focal length of the liquid lens unit 300 may be changed. When the boundary surface deformation and curvature change are controlled, the liquid lens unit 300 and the lens assembly and camera module including the same may perform an optical zoom function, an autofocusing function, a hand shake correction function, and the like.

4 illustrates a lens whose focal length is adjusted in response to a driving voltage. Specifically, (a) describes the first lens 28 included in the lens assembly 22 (refer to FIG. 3), and (b) describes the equivalent circuit of the lens 28.

First, referring to (a), the lens 28 whose focal length is adjusted in response to a driving voltage may receive an operating voltage through individual terminals L1, L2, L3, and L4. The individual terminals may have the same angular distance, and may include four individual terminals disposed in different directions. When an operating voltage is applied through the individual terminals L1 , L2 , L3 , and L4 , the interface between the conductive liquid and the non-conductive liquid formed in the lens region 310 may be deformed.

In addition, referring to (b), one side of the lens 28 receives operating voltages from different individual terminals (L1, L2, L3, L4), and the other side is a plurality of capacitors connected to the common terminal (C0) ( 30) can be explained. Here, the plurality of capacitors 30 included in the equivalent circuit may have a small capacitance of about 200 picofarads (pF).

5 illustrates the interfacial motion of a liquid lens. Specifically, (a) to (d) are movements of the interfaces 30a, 30b, 30c, and 30d that may occur when a driving voltage is applied to the individual electrodes L1, L2, L3, and L4 of the liquid lens 28. explain

First, referring to (a), when substantially the same driving voltage is applied to the individual electrodes L1 , L2 , L3 , and L4 of the liquid lens 28 , the interface 30a may maintain a shape close to a circular shape. In this case, there is substantially no difference between the driving voltage applied to the first individual electrode L1 and the third individual electrode L3 and the driving voltage applied to the second individual electrode L2 and the fourth individual electrode L4. Therefore, the distance LH between the first individual electrode L1 and the third individual electrode L3 and the distance LV between the second individual electrode L2 and the fourth individual electrode L4 are substantially the same, and , the movement (eg, inclination angle) of the interface 30a may have a balanced shape.

Also, referring to (b), the driving voltage applied to the first individual electrode L1 and the third individual electrode L3 of the liquid lens 28 is applied to the second individual electrode L2 and the fourth individual electrode L4. A case that is slightly lower than the driving voltage applied to . In this case, the length in the horizontal direction (that is, the distance LH between the first individual electrode L1 and the third individual electrode L3) is vertical because the force pulling or pushing the interface 30b is different from horizontal or vertical. It may be shorter than the length of the direction (ie, the distance LV between the second individual electrode L2 and the fourth individual electrode L4 ). When the driving voltage applied to the second individual electrode L2 and the fourth individual electrode L4 is higher than that of the first individual electrode L1 and the third individual electrode L3, the second individual electrode L2 and the second individual electrode L4 The inclination angle of the interface 30 of the liquid lens 28 at the four individual electrodes L4 is the inclination angle of the interface 30 of the liquid lens 28 at the first individual electrode L1 and the third individual electrode L3. Since it is higher, the length LV in the vertical direction becomes longer than the length LH in the horizontal direction in three dimensions, although it looks the same on a plane.

Also, referring to (c), the driving voltage applied to the first individual electrode L1 and the third individual electrode L3 of the liquid lens 28 and the second individual electrode L2 and the fourth individual electrode L4 ), a case in which the driving voltages applied to the voltages have a large difference will be described. In this case, the force pulling or pushing the interface 30c may show a large difference horizontally or vertically, so that the outer and edge of the interface 30c may be bent or the interface 30c may be distorted. This phenomenon may result in the liquid lens 28 being distorted. Here, the driving voltage applied to the first individual electrode L1 and the third individual electrode L3 of the liquid lens 28 and the driving voltage applied to the second individual electrode L2 and the fourth individual electrode L4 are Whether the liquid lens 28 is distorted from a certain degree of difference may vary depending on the structure and properties of the liquid lens 28 . For example, when an inclination of 0.6 degrees or more in a specific direction is compensated for through an image stabilization (OIS) function, the interface 30c of the liquid lens 28 may be distorted. In this case, the length in the horizontal direction (ie, the distance LH between the first individual electrode L1 and the third individual electrode L3) is the length in the vertical direction (ie, the second individual electrode L2 and the fourth individual electrode L3). The difference in the distance LV between the individual electrodes L4) becomes larger than in the case of the interface 30b described in (b).

Also, referring to (d), the driving voltage applied to the first individual electrode L1 and the third individual electrode L3 of the liquid lens 28 and the second individual electrode L2 and the fourth individual electrode L4 ) has a difference greater than or equal to a predetermined difference between the first and third electrodes L1 and L1 while maintaining the driving voltages applied to the second and fourth electrodes L2 and L4. By floating the individual electrode L3, it is possible to prevent the outer and edge of the interface 30d from being bent or the interface 30d from being crushed. Here, the floating state well known to those skilled in the art may include a floating state whose state is unknown. A floating state may be created by disconnecting the first voltage, the second voltage, and the ground voltage. The floating state may be a state in which the connection between the voltage source and the ground (reference potential) is cut off. When some of the electrodes included in the liquid lens 28 are floated for a preset time or period, the force in the direction in which the corresponding electrodes are positioned may be temporarily stopped. It may be difficult to clearly explain the potential difference on the floating electrode, but unlike the case where an imbalance occurs by applying a force to the interface 30c in a specific direction as in the case described in (c), in (d), the interface 30d through the floating can induce a natural balance of power in Accordingly, the length in the horizontal direction (ie, the distance LH between the first individual electrode L1 and the third individual electrode L3) is the length in the vertical direction (ie, the second individual electrode L2 and the fourth individual electrode L2). Even if the difference in the distance LV between the electrodes L4) is large, it is possible to prevent the liquid lens 28 from being distorted.

6 illustrates a first driving method of the liquid lens.

As shown, preset voltages (eg, ground voltage (0V) and high voltage (70V)) are applied to the plurality of individual electrodes (L1, L2, L3, L4) and the common electrode (C0) included in the liquid lens. The interface of the liquid lens can be controlled. A ground voltage in the present specification may be a reference potential in the control circuit, and the ground voltage may be a reference voltage in the control circuit.

The movement of the liquid lens interface can be controlled by the potential difference between the individual electrodes and the common electrode. To apply a ground voltage (0V) to one electrode of the liquid lens and a high voltage (70V) to the other electrode, turn on the switch connected between the ground voltage (0V) and one electrode and output from the voltage booster in the control circuit An operation of turning on a switch capable of supplying the high voltage (70V) to the other electrode may be performed.

7 illustrates a second driving method of the liquid lens.

As shown, preset voltages (eg, ground voltage (0V) and high voltage (70V)) are applied to the plurality of individual electrodes (L1, L2, L3, L4) and the common electrode (C0) included in the liquid lens. The interface of the liquid lens can be controlled. In FIG. 7, unlike FIG. 6, some electrodes may be floated to control the interface of the liquid lens. For example, a high voltage (70V) may be applied to one electrode of the liquid lens for a preset time, and a floating state may be maintained instead of a ground voltage (0V) to the other electrode.

Specifically, a case in which the first individual electrode L1 is not floated (1) and a case in which the first individual electrode L1 is floated (2) may be compared through the timing diagram. When the first individual electrode L1 is floated, the floating voltage floating V may be in a free state although it is difficult to clearly explain. For example, when the first individual electrode L1 is floated, the potential of the first individual electrode may gradually decrease, or rise and fall may be repeated. However, it can be assumed that the high voltage (70V) is applied in a free state and then gradually decreases when it becomes a floating state. Although the state is unknown, when some electrodes remain in a floating state and a driving voltage is applied to the other electrodes, as shown in FIG. can do.

Fig. 8 describes a first example of the control circuit. Here, the control circuit is a circuit for applying an operating voltage to the lens 28 (refer to FIG. 4 ), which is included in the lens assembly 22 and whose focal length is adjusted in response to the driving voltage. When described using an equivalent circuit, the lens 28 can be described as including a plurality of capacitors 30 , and individual terminals L1 , L2 , L3 , L4 supplying an operating voltage to each capacitor 30 . ) may be independently controllable. Hereinafter, for convenience of description, one capacitor 30 connected to one individual terminal will be described as an example in describing the control circuit.

As shown, the control circuit may include an individual terminal control unit 34 and a common terminal control unit 36 . The individual terminal control unit 34 and the common terminal control unit 36 may receive a ground voltage as a power supply voltage, and may receive an operating voltage having a magnitude of 1/2 of the driving voltage from the voltage booster 32 . The individual terminal control unit 34 may supply an operating voltage in the form of a positive voltage and a negative voltage to the individual terminals of the capacitor 30 , and the common terminal control unit 36 is the capacitor 30 . An operating voltage in the form of a positive voltage and a negative voltage may be supplied to the common terminal. When the ground voltage, the reference potential, or the reference voltage is 0V, the individual terminal control unit 34 may supply an operating voltage in the form of a positive voltage and a negative voltage to the individual terminals, and the common terminal control unit Reference numeral 36 may supply an operating voltage in the form of a positive voltage and a negative voltage to the common terminal of the capacitor 30 . The individual terminal control unit 34 and the common terminal control unit 36 may have substantially the same configuration. Hereinafter, the individual terminal control unit 34 will be described in more detail.

The individual terminal control 34 may include a charge pump 46 for regulating the operating voltage provided by the voltage booster 32 in the form of a negative voltage. In addition, the individual terminal control unit 34 may include a switching unit including a plurality of switches. The switching unit includes a first switch 42 for selecting one of a ground voltage and an operating voltage, a second switch 48 for selecting one of an output of the charge pump 46 and a ground voltage, and a first switch 42 . and a third switch 44 that selects one of the outputs of the second switch 48 and applies it to individual terminals of the capacitor 30 . Here, the first switch 42 , the second switch 48 , and the third switch 44 may include at least one transistor. Also, each switch may include two transistors.

On the other hand, the first switch 42 and the second switch 48 in the individual terminal control unit 34 use the ground voltage as a bias voltage to control the operating voltage applied to the individual terminal or the common terminal of the capacitor 30 . can decide

In addition, the control circuit may further include a voltage booster 32 that converts the supply voltage Vin to the level of the operating voltage. For example, a supply voltage input to the voltage booster 32 may have a level of 2.5 to 3.0 V, and an operating voltage output from the voltage booster 32 may have a level of 30 to 40 V. Here, the supply voltage input to the voltage booster 32 may be the operating voltage of the portable device on which the camera module is mounted.

Meanwhile, the individual terminal control unit 34 and the common terminal control unit 36 are supplied with a ground voltage as a power supply voltage. This can reduce power consumption compared to a case in which the operating voltage that is the output of the voltage booster 32 is applied as a power supply voltage. For example, when the operating voltage that is the output of the voltage booster 32 is applied as a power supply voltage, when the control circuit does not need to operate, the operating voltage is not transmitted by the switches 42 , 44 , 48 , but operates Since the voltage is continuously being applied to the switch, power consumption may occur. In the case of a camera module mounted on a portable device, it may be important to reduce power consumption. Accordingly, the output of the voltage booster 32 is not connected to the power supply voltage of the individual terminal control unit 34 and the common terminal control unit 36 , but is connected to the switch 42 .

9 illustrates a second example of the control circuit.

As shown, the control circuit connected to the voltage booster 32 receiving the supply voltage Vin and outputting the operating voltage may control the voltage applied to the individual terminals of the capacitor 30 .

The control circuit may include a first voltage stabilizer 52 for stabilizing the output of the voltage booster 32 . In addition, the output of the voltage booster 32 is transmitted to a first charge pump (charge pump, 46). The first charge pump 46 includes a first element selectively transferring a ground voltage, a second element selectively transferring an operating voltage, and a first capacitor positioned between the outputs of the first and second elements and the switching unit. may include Here, the first device and the second device may be implemented as transistors.

Meanwhile, the first switch 42 for selecting one of the ground voltage and the operating voltage may include a third device for selectively transmitting the ground voltage and a fourth device for selectively transmitting the operating voltage.

In addition, the second switch 48 for selecting one of the output of the first charge pump 46 and the ground voltage selects a fifth element for selectively transferring the output of the first charge pump 46, and a ground voltage. It may include a sixth element for selectively delivering.

Through this, both the first switch 42 and the second switch 48 may selectively transmit the ground voltage. As an operating voltage applied to one side of the capacitor 30, since both the first switch 42 and the second switch 48 may transmit a ground voltage, if one of the two transmits the operating voltage, the other is the ground voltage. It may be connected to and may determine the positive voltage or negative voltage form of the operating voltage.

In addition, the third switch 44 that selects one of the outputs of the first switch 42 and the second switch 48 and applies it to individual terminals of the capacitor 30 selectively selects the output of the first switch 42 . It may include a seventh element for transferring and an eighth element for selectively transferring the output of the second switch 48 .

In addition, the control circuit may include a common terminal control unit 36 . The common terminal control unit 36 may include a second voltage stabilization unit 54 , a second charge pump 66 , a fourth switch 62 , a fifth switch 68 , and a sixth switch 64 . . Here, the second voltage stabilizer 54 may have the same configuration as the first voltage stabilizer 54 , and the second charge pump 66 may have the same configuration as the first charge pump 46 . In addition, the fourth switch 62 has the same configuration as the first switch 42 , the fifth switch 68 has the same configuration as the second switch 48 , and the sixth switch 64 has the third switch It may have the same configuration as (44).

Fig. 10 explains the structure of the liquid lens.

As shown, the liquid lens 28 may include a liquid, a first plate, and an electrode. The liquids 122 and 124 included in the liquid lens 28 may include a conductive liquid and a non-conductive liquid. The first plate may include a cavity 150 in which a conductive liquid and a non-conductive liquid are disposed. The cavity 150 may include an inclined surface. The electrodes 132 and 134 may be disposed on the first plate 114 , and may be disposed above the first plate 114 or below the first plate 114 . The liquid lens 28 may further include a second plate 112 that may be disposed above (below) the electrodes 132 and 134 . In addition, the liquid lens 28 may further include a third plate 116 that may be disposed under (upper) the electrodes 132 and 134 . As shown, one embodiment of a liquid lens 28 may include an interface 130 formed by two different liquids 122 , 124 . It may also include at least one substrate 142 , 144 for supplying a voltage to the liquid lens 28 . The edge of the liquid lens 28 may be thinner than the center of the liquid lens 28 .

The liquid lens 28 includes two different liquids, for example, a conductive liquid 122 and a non-conductive liquid 124 , and the curvature and shape of the interface 130 formed by the two liquids are in the liquid lens 28 . It can be adjusted by the supplied driving voltage. The driving voltage supplied to the liquid lens 28 may be transmitted through the first substrate 142 and the second substrate 144 . The second substrate 144 may transmit four distinct driving voltages, and the first substrate 142 may transmit one common voltage. The voltage supplied through the second substrate 144 and the first substrate 142 may be applied to the plurality of electrodes 134 and 132 exposed at each corner of the liquid lens 28 .

In addition, the liquid lens 28 is located between the third plate 116 and the second plate 112, the third plate 116 and the second plate 112 including a transparent material, and has an opening having a preset inclined surface. It may include a first plate 114 including a region.

In addition, the liquid lens 28 may include a cavity 150 determined by the opening areas of the third plate 116 , the second plate 112 , and the first plate 114 . Here, the cavity 150 may be filled with two liquids 122 and 124 of different properties (eg, a conductive liquid and a non-conductive liquid), and an interface 130 between the two liquids 122 and 124 of different properties. ) can be formed.

In addition, at least one of the two liquids 122 and 124 included in the liquid lens 28 has conductivity, and the liquid lens 28 has two electrodes 132 and 134 disposed above and below the first plate 114 . and an insulating layer 118 disposed on an inclined surface to which the conductive liquid may come into contact. Here, the insulating layer 118 covers one of the two electrodes 132 and 134 (eg, the second electrode 134 ), and exposes a portion of the other electrode (eg, the first electrode 132 ). to allow electrical energy to be applied to the conductive liquid (eg, 122). Here, the first electrode 132 includes at least one electrode sector (eg, C0), and the second electrode 134 includes two or more electrode sectors (eg, L1, L2, L3, L4 in FIG. 4). can do. For example, the second electrode 134 may include a plurality of electrode sectors sequentially arranged in a clockwise direction with respect to the optical axis. In this specification, the electrode sector may be referred to as a sub-electrode.

One or two or more substrates 142 and 144 for transmitting a driving voltage to the two electrodes 132 and 134 included in the liquid lens 28 may be connected. The focal length of the liquid lens 28 may be adjusted as the curvature and inclination of the interface 130 formed in the liquid lens 28 change in response to the driving voltage.

11 illustrates a third example of the control circuit.

As shown, the control circuit includes a driving voltage output unit 230A that outputs a voltage having a preset magnitude having a polarity (positive or negative), a voltage received from the driving voltage output unit 230A and a ground voltage (ground voltage) The first switching unit 240 selectively transmits one of the driving voltages transmitted from the first switching unit 240, and the second switching unit selectively transmits the driving voltage transmitted from the liquid lens 28 (refer to FIG. 7) to the electrode 260 of the liquid lens 28 (refer to FIG. 7). part 250 may be included.

The driving voltage output unit 230A increases the voltage to a preset level based on the power supply voltage or the supply voltage to output the first voltage and receives the first voltage from the first voltage generator 232 and the first voltage generator 232 . The charge pump 234 may include a charge pump 234 that is received and outputs the second voltage by changing the polarity.

The first switching unit 240 includes a first switch 242 capable of selectively transmitting the first voltage transmitted from the first voltage generator 232 and a second switch 244 capable of selectively transmitting a first ground voltage. may include In addition, the first switching unit 240 includes a fourth switch 246 capable of selectively transmitting the second voltage transmitted from the charge pump 234 and a fifth switch 248 capable of selectively transmitting the second ground voltage. may further include.

The first switching unit 240 may include two different input terminals and two different output terminals. Also, the first ground voltage and the second ground voltage may be electrically connected.

The second switching unit 250 includes a third switch 252 that can selectively supply the liquid lens electrode 260 when one of the first voltage and the first ground voltage is transmitted, and one of the second voltage and the second ground voltage. When is delivered, a sixth switch 254 that can selectively supply the liquid lens electrode 260 may be included.

The first switching unit 240 may be disposed in common with the electrode included in the liquid lens 28 . For example, the first switching unit 240 may be shared between the plurality of individual electrodes included in the liquid lens to transmit a driving voltage to the plurality of individual electrodes through the at least one first switching unit 240 .

On the other hand, the second switching unit 250 needs to be individually arranged for each electrode included in the liquid lens 28 . For example, an independent second switching unit 250 may be connected to each of a plurality of individual electrodes included in the liquid lens 28 , so that the second switching unit 250 may not be shared between the liquid lens electrodes 260 . have.

12 illustrates a fourth example of the control circuit.

As shown, the control circuit includes a voltage generator 232 that generates a voltage having a preset polarity and magnitude, a charge pump 234 that converts the polarity of the voltage generated by the voltage generator 232, and the liquid lens. A plurality of switching elements 242a, 242b, 244a, 244b, 244c, 244d, 244e, 246a, 246b, 248a, 248b for transferring a driving voltage to the included plurality of electrodes L1, L2, L3, L4, C0 , a plurality of second switching units (250a, 250b, 250c, 250d, 250e) may be included. Here, the plurality of switching elements 242a, 242b, 244a, 244b, 244c, 244d, 244e, 246a, 246b, 248a, and 248b may correspond to the first switching unit 240 described with reference to FIG. 8 .

Except for the three switch elements included in the charge pump 234 , according to the control circuit described with reference to FIG. 11 , six switch elements may be connected to each liquid lens electrode 260 . However, in the control circuit described with reference to FIG. 12, some switch elements disposed on the individual electrodes L1, L2, L3, and L4 among the plurality of electrodes L1, L2, L3, L4, C0 included in the liquid lens are commonly connected. By doing so, the number of switch elements can be reduced. For example, when the liquid lens includes four individual electrodes and one common electrode, a total of 30 (5 X 6) switching elements may be included in the control circuit described in FIG. 11, but the control circuit described in FIG. 12 is A total of 21 switching devices may be included.

13 illustrates a fifth example of the control circuit.

As shown, the control circuit includes a voltage generator 232 that generates a voltage having a preset polarity and magnitude, a charge pump 234 that converts the polarity of the voltage generated by the voltage generator 232, and the liquid lens. A plurality of switching elements 242a, 242b, 244a, 244b, 246a, 246b, 248a, 248b for transferring a driving voltage to the included plurality of electrodes L1, L2, L3, L4, C0, from the plurality of switching elements A plurality of second switching units (250a, 250b, 250c, 250d, 250e) for selectively transferring the transferred voltage to the plurality of electrodes (L1, L2, L3, L4, C0) included in the liquid lens may be included. have. Here, the plurality of switching elements 242a, 242b, 244a, 244b, 246a, 246b, 248a, and 248b may correspond to the first switching unit 240 described with reference to FIG. 8 .

Except for the three switch elements included in the charge pump 234, when the liquid lens includes four individual electrodes and one common electrode, the control circuit described in FIG. 12 may include 21 switching elements, but FIG. The control circuit described in 13 may include 18 switching elements. The number of switching elements included in the control circuit can be further reduced as shown in FIG. 13 by a method of connecting in common rather than individually disposing switching elements for selectively transferring the ground voltage to each of the individual electrodes included in the liquid lens. . Reducing the number of switching elements can reduce the overall size of the control circuit and reduce power consumption.

13, the number of the plurality of switching elements 242a, 242b, 244a, 244b, 246a, 246b, 248a, 248b corresponding to the first switching unit 240 described in FIG. 11 is the number of electrodes included in the liquid lens. can be fixed irrespective of the number of For example, regardless of whether the number of individual electrodes included in the liquid lens is 4, 8, 12, or 16, the first switching unit 240 described in FIG. 8 can be implemented with only 8 switching elements. On the other hand, the number of switching elements included in the plurality of second switching units 250a, 250b, 250c, 250d, and 250e may correspond to the number of electrodes included in the liquid lens, that is, the sum of the individual electrodes and the common electrode. That is, the number of switching elements included in the plurality of second switching units 250a, 250b, 250c, 250d, and 250e may be double the sum of the number of individual electrodes and common electrodes included in the liquid lens. For example, if there are four individual electrodes and one common electrode included in the liquid lens, the number of electrodes may be five and the number of switching elements included in the plurality of second switching units may be ten.

If the number of individual electrodes included in the liquid lens is 8 and the common electrode is one, the number of electrodes may be 9 and the number of switching elements included in the plurality of second switching units may be 18. Meanwhile, according to embodiments, even if the number of electrodes included in the liquid lens is changed, the number of switching elements included in the driving voltage control circuit may be fixed.

Fig. 14 explains a first operation example of the control circuit shown in Fig. 13; The liquid lens 28 (see FIGS. 4 and 10) includes four individual electrodes L1, L2, L3, L4 and one common electrode C0, a first individual electrode L1 and a third individual electrode (L3), it is assumed that the second individual electrode (L2) and the fourth individual electrode (L4) are arranged to be symmetrical to each other with respect to the center of the liquid lens (28). Hereinafter, for convenience of explanation, the driving voltage applied to the first individual electrode L1 , the second individual electrode L2 , and the common electrode C0 will be mainly described. In particular, FIG. 14 describes a case in which a positive voltage is applied to the common electrode C0.

When the first individual electrode (L1), the third individual electrode (L3), the second individual electrode (L2), and the fourth individual electrode (L4) are arranged symmetrically with respect to the center of the liquid lens 28, The same driving voltage may be applied to the first individual electrode L1 and the third individual electrode L3 , and the same driving voltage may be applied to the second individual electrode L2 and the fourth individual electrode L4 . Depending on the embodiment, different driving voltages may be applied to the first individual electrode L1 , the second individual electrode L2 , the third individual electrode L3 , and the fourth individual electrode L4 . For example, at the same time t, a driving voltage may be applied to the other individual electrodes L3 and L4 symmetrically with the first individual electrode L1 and the second individual electrode L2, and different driving voltages may be applied. can be authorized

As shown, referring to the timing diagram, a plurality of operation modes (①, ②, ③, ④, ⑤, ⑥) may exist. First, in the first mode (①), a ground voltage is applied to all of the common electrode C0, the second individual electrode L2, and the first individual electrode L1. In the second mode (②), the positive voltage generated by the voltage generator 232 is applied to the common electrode C0 , and a ground voltage is applied to the first individual electrode L1 and the second individual electrode L2 . In the third mode (③), the positive voltage generated by the voltage generator 232 is applied to the common electrode C0, and the negative voltage transmitted from the charge pump is applied to the first and second individual electrodes L1 and L2. voltage is applied. In the fourth mode (④), the first individual electrode L1 is floating, and the second individual electrode L2 and the common electrode C0 are not floating. Accordingly, in the fourth mode (④), a ground voltage is applied to the common electrode C0 and a negative voltage is applied to the second individual electrode L2, but the first individual electrode L1 is floated. Referring to the timing diagram, it is described that the voltage of the floating first individual electrodes L1 is gradually lowered in the fourth mode (④), but the voltage of the floating first individual electrodes L1 is difficult to predict. may have Accordingly, a potential difference between the non-floating second individual electrode L2 and the common electrode C0 may be clear. On the other hand, although it is difficult to clearly explain the potential difference between the first individual electrode L1 and the common electrode C0, in the floating state, the movement of charges may be made more naturally than artificially controlled. If the electric charge moves naturally, the potential difference may gradually decrease as shown in the timing diagram. In the fifth mode (⑤), a ground voltage is applied to the common electrode C0 and the first individual electrode L1 is floating, but the negative voltage transmitted from the charge pump is applied to the second individual electrode L2. is transmitted In the sixth mode (⑥), a ground voltage is applied to all of the common electrode C0, the first individual electrode L1, and the second individual electrode L2.

In the first to sixth modes (①,②,③,④,⑤,⑥), the movement of the interface 130 included in the liquid lens 28 is performed between the common electrode C0 and the first individual electrode L1 or It may be determined by the magnitude of the driving voltage Vop applied between the second individual electrodes L2. In this case, the movement of the interface 130 may be controlled by the absolute value of the magnitude regardless of the polarity of the driving voltage Vop. For example, when the first individual electrode L1 and the third individual electrode L3 are floated and a constant potential difference (ie, driving voltage) is maintained between the second individual electrode L2 and the fourth individual electrode L4 , it is possible to realize a more natural movement of the interface 130 as described in FIG.

In the first to sixth modes (①,②,③,④,⑤,⑥), the driving voltage applied to the first individual electrode L1 and the common electrode C0 is applied to the plurality of switch elements included in the control circuit. It may be determined by ON/OFF. When a ground voltage, a positive voltage, or a negative voltage is applied to the first individual electrode L1, the second individual electrode L2, and the common electrode C0, which path and through which switch element can be transmitted is shown in FIG. It may be indicated by a dotted line and an arrow.

Meanwhile, the paths indicated by the dotted line and arrows indicated on the circuit diagram of FIG. 14 are given as an example, and the first individual electrode L1, the second individual electrode L2, and the common A driving voltage may be transmitted to the electrode C0.

Fig. 15 explains a second operation example of the control circuit shown in Fig. 13; The liquid lens 28 (see FIGS. 4 and 10) includes four individual electrodes L1, L2, L3, L4 and one common electrode C0, a first individual electrode L1 and a third individual electrode (L3), it is assumed that the second individual electrode (L2) and the fourth individual electrode (L4) are arranged to be symmetrical to each other with respect to the center of the liquid lens (28). Hereinafter, for convenience of explanation, the driving voltage applied to the first individual electrode L1 , the second individual electrode L2 , and the common electrode C0 will be mainly described. In particular, FIG. 15 describes a case in which a negative voltage is applied to the common electrode C0.

When the first individual electrode (L1), the third individual electrode (L3), the second individual electrode (L2), and the fourth individual electrode (L4) are arranged symmetrically with respect to the center of the liquid lens 28, The same driving voltage may be applied to the first individual electrode L1 and the third individual electrode L3 , and the same driving voltage may be applied to the second individual electrode L2 and the fourth individual electrode L4 . Depending on the embodiment, different driving voltages may be applied to the first individual electrode L1 , the second individual electrode L2 , the third individual electrode L3 , and the fourth individual electrode L4 . For example, at the same time t, a driving voltage may be applied to the other individual electrodes L3 and L4 symmetrically with the first individual electrode L1 and the second individual electrode L2, and different driving voltages may be applied. can be authorized

As shown, referring to the timing diagram, a plurality of operation modes (①, ②, ③, ④, ⑤, ⑥) may exist. First, in the first mode (①), a ground voltage is applied to all of the common electrode C0, the second individual electrode L2, and the first individual electrode L1. In the second mode (②), the negative voltage transmitted from the charge pump that converts the positive voltage generated by the voltage generator 232 to output a negative voltage is applied to the common electrode C0, and the first individual electrode L1 and a ground voltage is applied to the second individual electrode L2. In the third mode (③), the negative voltage transmitted from the charge pump is applied to the common electrode C0, and the positive voltage generated by the voltage generator 232 is applied to the first and second individual electrodes L1 and L2. voltage is applied. In the fourth mode (④), the first individual electrode L1 is floating, and the second individual electrode L2 and the common electrode C0 are not floating. Accordingly, in the fourth mode (④), a negative voltage is applied to the common electrode C0 and a positive voltage is applied to the second individual electrode L2, but the first individual electrode L1 is floated. Referring to the timing diagram, it is described that the voltage of the floating first individual electrode L1 is gradually lowered in the fourth mode (④), but the voltage of the first individual electrode L1 that is floated is difficult to predict. may have Accordingly, a potential difference between the non-floating second individual electrode L2 and the common electrode C0 may be clear. On the other hand, although it is difficult to clearly explain the potential difference between the first individual electrode L1 and the common electrode C0, in the floating state, the movement of charges may be made more naturally than by artificial control. If the electric charge moves naturally, the potential difference may gradually decrease as shown in the timing diagram. In the fifth mode ⑤, a ground voltage is applied to the common electrode C0 and the first individual electrode L1 is floating, but the voltage generator 232 generates the second individual electrode L2. positive voltage is transmitted. In the sixth mode (⑥), a ground voltage is applied to all of the common electrode C0, the first individual electrode L1, and the second individual electrode L2.

In the first to sixth modes (①,②,③,④,⑤,⑥), the movement of the interface 130 included in the liquid lens 28 is performed between the common electrode C0 and the first individual electrode L1 or It may be determined by the magnitude of the driving voltage Vop applied between the second individual electrodes L2. In this case, the movement of the interface 130 may be controlled by the absolute value of the magnitude regardless of the polarity of the driving voltage Vop. For example, when the first individual electrode L1 and the third individual electrode L3 are floated and a constant potential difference (ie, driving voltage) is maintained between the second individual electrode L2 and the fourth individual electrode L4 , it is possible to implement a more natural movement of the interface 130 as described in FIG. 5 , and to reduce damping that may occur due to a potential difference between individual electrodes.

In the first to sixth modes (①,②,③,④,⑤,⑥), the driving voltage applied to the first individual electrode L1 and the common electrode C0 is applied to the plurality of switch elements included in the control circuit. It may be determined by ON/OFF. When a ground voltage, a positive voltage, or a negative voltage is applied to the first individual electrode L1, the second individual electrode L2, and the common electrode C0, which path and through which switch element can be transmitted are shown in FIG. It may be indicated by a dotted line and an arrow.

14 and 15, voltages having opposite polarities are applied to the first individual electrode L1 or the second individual electrode L2 and the common electrode C0 to double the magnitude of the voltage applied to the electrode A driving voltage of may be applied to the liquid lens. Through this, when a driving voltage of about 70 V is required to control the movement of the interface included in the liquid lens, a voltage of about 35 V of different polarity is applied to the first individual electrode L1 and the common electrode C0 to approximately Substantially the same effect as that in which the driving voltage of 70V is applied can be obtained. A switching device that selectively transmits a lower voltage can be made smaller, thereby realizing the miniaturization of the control circuit and increasing the degree of integration.

16 illustrates a sixth example of the control circuit.

As shown, the control circuit includes a driving voltage output unit 230B for outputting a plurality of voltages having a preset size having a polarity (positive or negative), a voltage received from the driving voltage output unit 230B, and a ground voltage (ground). voltage) including a first switching unit 240 that selectively transmits one can do. Here, the liquid lens electrode 260 may be one of the plurality of electrodes 132 and 134 included in the liquid lens 28 (refer to FIG. 10 ).

The driving voltage output unit 230B includes a first voltage generator 232 for outputting a first voltage by increasing the voltage to a preset size based on the power supply voltage or supply voltage, and a power supply voltage or supply voltage to a preset size based on the power supply voltage or supply voltage. The second voltage generator 236 may include a second voltage generator 236 that increases the voltage and outputs a second voltage having a polarity opposite to that of the first voltage. Compared with the control circuit described with reference to FIG. 8 , the driving voltage output unit 230B may include a second voltage generator 236 capable of individually generating a second voltage instead of using the charge pump 234 .

The first switching unit 240 includes a first switch 242 capable of selectively transmitting the first voltage transmitted from the first voltage generator 232 and a second switch 244 capable of selectively transmitting a first ground voltage. may include In addition, the first switching unit 240 includes a fourth switch 246 capable of selectively transmitting the second voltage transmitted from the charge pump 234 and a fifth switch 248 capable of selectively transmitting the second ground voltage. may further include.

The first switching unit 240 may include two different input terminals and two different output terminals. Also, the first ground voltage and the second ground voltage may be electrically connected.

The second switching unit 250 includes a third switch 252 that can selectively supply the liquid lens electrode 260 when one of the first voltage and the first ground voltage is transmitted, and one of the second voltage and the second ground voltage. When is delivered, a sixth switch 254 that can selectively supply the liquid lens electrode 260 may be included.

The first switching unit 240 may be disposed in common with the electrode included in the liquid lens 28 . For example, the first switching unit 240 may be shared between the plurality of individual electrodes included in the liquid lens to transmit a driving voltage to the plurality of individual electrodes through the at least one first switching unit 240 .

On the other hand, the second switching unit 250 needs to be individually arranged for each electrode included in the liquid lens 28 . For example, an independent second switching unit 250 may be connected to each of a plurality of individual electrodes included in the liquid lens 28 , so that the second switching unit 250 may not be shared between the liquid lens electrodes 260 . have.

17 illustrates a seventh example of the control circuit.

As illustrated, the control circuit includes a first voltage generator 232 that generates a voltage having a preset polarity and a magnitude, and is output from the first voltage generator 232 independently of the first voltage generator 232 . A second voltage generator 236 for generating a voltage having a polarity opposite to the voltage, and a plurality of switching devices for transferring a driving voltage to the plurality of electrodes L1, L2, L3, L4, and C0 included in the liquid lens (242a, 242b, 244a, 244b, 244c, 244d, 244e, 246a, 246b, 248a, 248b), a plurality of electrodes (L1, L2, L3, L4, C0) may include a plurality of second switching units (250a, 250b, 250c, 250d, 250e) for selectively transmitting. Here, the plurality of switching elements 242a, 242b, 244a, 244b, 244c, 244d, 244e, 246a, 246b, 248a, and 248b may correspond to the first switching unit 240 described with reference to FIG. 16 .

According to the control circuit described with reference to FIG. 17 , six switch elements may be connected to each liquid lens electrode 260 . However, in the control circuit described with reference to FIG. 14, some switch elements disposed on the individual electrodes L1, L2, L3, and L4 among the plurality of electrodes L1, L2, L3, L4, C0 included in the liquid lens are commonly connected. By doing so, the number of switch elements can be reduced. For example, when the liquid lens includes four individual electrodes and one common electrode, a total of 30 (5 X 6) switching elements may be included in the control circuit described in FIG. 16, but the control circuit described in FIG. A total of 21 switching devices may be included.

18 illustrates an eighth example of a control circuit.

As illustrated, the control circuit includes a first voltage generator 232 that generates a voltage having a preset polarity and a magnitude, and is output from the first voltage generator 232 independently of the first voltage generator 232 . A second voltage generator 236 for generating a voltage having a polarity opposite to the voltage, and a plurality of switching devices for transferring a driving voltage to the plurality of electrodes L1, L2, L3, L4, and C0 included in the liquid lens (242a, 242b, 244a, 244b, 246a, 246b, 248a, 248b), the voltage transmitted from the plurality of switching elements is selectively transferred to the plurality of electrodes (L1, L2, L3, L4, C0) included in the liquid lens It may include a plurality of second switching units 250a, 250b, 250c, 250d, and 250e for Here, the plurality of switching elements 242a, 242b, 244a, 244b, 246a, 246b, 248a, and 248b may correspond to the first switching unit 240 described with reference to FIG. 16 .

When the liquid lens includes four individual electrodes and one common electrode, the control circuit described in FIG. 12 may include 21 switching elements, but the control circuit described in FIG. 18 may include 18 switching elements. The number of switching elements included in the control circuit can be further reduced as shown in FIG. 18 by a method of connecting in common rather than individually disposing switching elements for selectively transferring the ground voltage to each individual electrode included in the liquid lens. . Reducing the number of switching elements can reduce the overall size of the control circuit and reduce power consumption.

18, the number of the plurality of switching elements 242a, 242b, 244a, 244b, 246a, 246b, 248a, 248b corresponding to the first switching unit 240 described in FIG. 16 is the number of electrodes included in the liquid lens. can be fixed irrespective of the number of For example, regardless of whether the number of individual electrodes included in the liquid lens is 4, 8, 12, or 16, the first switching unit 240 described in FIG. 16 can be implemented with only 8 switching elements. On the other hand, the number of switching elements included in the plurality of second switching units 250a, 250b, 250c, 250d, and 250e may correspond to the number of electrodes included in the liquid lens, that is, the sum of the individual electrodes and the common electrode. That is, the number of switching elements included in the plurality of second switching units 250a, 250b, 250c, 250d, and 250e may be double the sum of the number of individual electrodes and common electrodes included in the liquid lens. For example, if there are four individual electrodes and one common electrode included in the liquid lens, the number of electrodes may be five and the number of switching elements included in the plurality of second switching units may be ten.

If the number of individual electrodes included in the liquid lens is 8 and the common electrode is one, the number of electrodes may be 9 and the number of switching elements included in the plurality of second switching units may be 18. Meanwhile, according to embodiments, even if the number of electrodes included in the liquid lens is changed, the number of switching elements included in the driving voltage control circuit may be fixed.

Fig. 19 explains a first operation example of the control circuit shown in Fig. 18; The liquid lens 28 (see FIGS. 4 and 10) includes four individual electrodes L1, L2, L3, L4 and one common electrode C0, a first individual electrode L1 and a third individual electrode (L3), it is assumed that the second individual electrode (L2) and the fourth individual electrode (L4) are arranged to be symmetrical to each other with respect to the center of the liquid lens (28). Hereinafter, for convenience of explanation, the driving voltage applied to the first individual electrode L1 , the second individual electrode L2 , and the common electrode C0 will be mainly described. In particular, FIG. 19 describes a case in which a positive voltage is applied to the common electrode C0.

When the first individual electrode (L1), the third individual electrode (L3), the second individual electrode (L2), and the fourth individual electrode (L4) are arranged symmetrically with respect to the center of the liquid lens 28, The same driving voltage may be applied to the first individual electrode L1 and the third individual electrode L3 , and the same driving voltage may be applied to the second individual electrode L2 and the fourth individual electrode L4 . Depending on the embodiment, different driving voltages may be applied to the first individual electrode L1 , the second individual electrode L2 , the third individual electrode L3 , and the fourth individual electrode L4 . For example, at the same time t, a driving voltage may be applied to the other individual electrodes L3 and L4 symmetrically with the first individual electrode L1 and the second individual electrode L2, and different driving voltages may be applied. can be authorized

As shown, referring to the timing diagram, a plurality of operation modes (①, ②, ③, ④, ⑤, ⑥) may exist. First, in the first mode (①), a ground voltage is applied to all of the common electrode C0, the second individual electrode L2, and the first individual electrode L1. In the second mode (②), the positive voltage generated by the first voltage generator 232 is applied to the common electrode C0, and the ground voltage is applied to the first individual electrode L1 and the second individual electrode L2. do. In the third mode (③), the positive voltage generated by the first voltage generator 232 is applied to the common electrode C0, and a second voltage is generated to the first individual electrode L1 and the second individual electrode L2. The negative voltage transmitted from the unit 236 is applied. In the fourth mode (④), the first individual electrode L1 is floating, and the second individual electrode L2 and the common electrode C0 are not floating. Accordingly, in the fourth mode (④), a positive voltage is applied to the common electrode C0 and a negative voltage is applied to the second individual electrode L2, but the first individual electrode L1 is floated. Referring to the timing diagram, it is described that the voltage of the floating first individual electrodes L1 is gradually lowered in the fourth mode (④), but the voltage of the floating first individual electrodes L1 is difficult to predict. may have Accordingly, a potential difference between the non-floating second individual electrode L2 and the common electrode C0 may be clear. On the other hand, although it is difficult to clearly explain the potential difference between the first individual electrode L1 and the common electrode C0, in the floating state, the movement of charges may be made more naturally than by artificial control. If the electric charge moves naturally, the potential difference may gradually decrease as shown in the timing diagram. In the fifth mode (⑤), a ground voltage is applied to the common electrode C0 and the first individual electrode L1 is floating, but a second voltage generator 236 is applied to the second individual electrode L2. The negative voltage transmitted from In the sixth mode (⑥), a ground voltage is applied to all of the common electrode C0, the first individual electrode L1, and the second individual electrode L2.

In the first to sixth modes (①,②,③,④,⑤,⑥), the movement of the interface 130 included in the liquid lens 28 is performed between the common electrode C0 and the first individual electrode L1 or It may be determined by the magnitude of the driving voltage Vop applied between the second individual electrodes L2. In this case, the movement of the interface 130 may be controlled by the absolute value of the magnitude regardless of the polarity of the driving voltage Vop. For example, when the first individual electrode L1 and the third individual electrode L3 are floated and a constant potential difference (ie, driving voltage) is maintained between the second individual electrode L2 and the fourth individual electrode L4 , it is possible to realize a more natural movement of the interface 130 as described in FIG.

In the first to sixth modes (①,②,③,④,⑤,⑥), the driving voltage applied to the first individual electrode L1 and the common electrode C0 is applied to the plurality of switch elements included in the control circuit. It may be determined by ON/OFF. When a ground voltage, a positive voltage, or a negative voltage is applied to the first individual electrode L1, the second individual electrode L2, and the common electrode C0, which path and through which switch element can be transmitted is shown in FIG. It may be indicated by a dotted line and an arrow.

Meanwhile, the paths indicated by the dotted line and the arrows indicated on the circuit diagram of FIG. 19 are given as an example, and the driving voltage is applied to the first individual electrode L1 and the common electrode C0 in various combinations of different paths according to the embodiment. can transmit

Fig. 20 explains a second operation example of the control circuit shown in Fig. 18; The liquid lens 28 (see FIGS. 4 and 10) includes four individual electrodes L1, L2, L3, L4 and one common electrode C0, a first individual electrode L1 and a third individual electrode (L3), it is assumed that the second individual electrode (L2) and the fourth individual electrode (L4) are arranged to be symmetrical to each other with respect to the center of the liquid lens (28). Hereinafter, for convenience of description, the driving voltage applied to the first individual electrode L1 , the second individual electrode L2 , and the common electrode C0 will be mainly described. In particular, FIG. 20 describes a case in which a negative voltage is applied to the common electrode C0.

When the first individual electrode (L1), the third individual electrode (L3), the second individual electrode (L2), and the fourth individual electrode (L4) are arranged symmetrically with respect to the center of the liquid lens 28, The same driving voltage may be applied to the first individual electrode L1 and the third individual electrode L3 , and the same driving voltage may be applied to the second individual electrode L2 and the fourth individual electrode L4 . Depending on the embodiment, different driving voltages may be applied to the first individual electrode L1 , the second individual electrode L2 , the third individual electrode L3 , and the fourth individual electrode L4 . For example, at the same time t, a driving voltage may be applied to the other individual electrodes L3 and L4 symmetrically with the first individual electrode L1 and the second individual electrode L2, and different driving voltages may be applied. can be authorized

As shown, referring to the timing diagram, a plurality of operation modes (①, ②, ③, ④, ⑤, ⑥) may exist. First, in the first mode (①), a ground voltage is applied to all of the common electrode C0, the second individual electrode L2, and the first individual electrode L1. In the second mode (②), the negative voltage generated by the second voltage generator 236 is applied to the common electrode C0, and a ground voltage is applied to the first individual electrode L1 and the second individual electrode L2. do. In the third mode (③), the negative voltage generated by the second voltage generator 236 is applied to the common electrode C0, and a first voltage is generated to the first individual electrode L1 and the second individual electrode L2. The positive voltage generated by the unit 232 is applied. In the fourth mode (④), the first individual electrode L1 is floating, and the second individual electrode L2 and the common electrode C0 are not floating. Accordingly, in the fourth mode (④), a negative voltage is applied to the common electrode C0 and a positive voltage is applied to the second individual electrode L2, but the first individual electrode L1 is floated. Referring to the timing diagram, it is described that the voltage of the floating first individual electrodes L1 is gradually lowered in the fourth mode (④), but the voltage of the floating first individual electrodes L1 is difficult to predict. may have Accordingly, a potential difference between the non-floating second individual electrode L2 and the common electrode C0 may be clear. On the other hand, although it is difficult to clearly explain the potential difference between the first individual electrode L1 and the common electrode C0, in the floating state, the movement of charges may be made more naturally than artificially controlled. If the electric charge moves naturally, the potential difference may gradually decrease as shown in the timing diagram. In the fifth mode (5), a ground voltage is applied to the common electrode C0 and the first individual electrode L1 is floating, but the voltage generator 232 generates the second individual electrode L2. positive voltage is transmitted. In the sixth mode (⑥), a ground voltage is applied to all of the common electrode C0, the first individual electrode L1, and the second individual electrode L2.

In the first to sixth modes (①,②,③,④,⑤,⑥), the movement of the interface 130 included in the liquid lens 28 is performed between the common electrode C0 and the first individual electrode L1 or It may be determined by the magnitude of the driving voltage Vop applied between the second individual electrodes L2. In this case, the movement of the interface 130 may be controlled by the absolute value of the magnitude regardless of the polarity of the driving voltage Vop. For example, when the first individual electrode L1 and the third individual electrode L3 are floated and a constant potential difference (ie, driving voltage) is maintained between the second individual electrode L2 and the fourth individual electrode L4 , it is possible to implement a more natural movement of the interface 130 as described in FIG. 5 , and to reduce damping that may occur due to a potential difference between individual electrodes.

In the first to sixth modes (①,②,③,④,⑤,⑥), the driving voltage applied to the first individual electrode L1 and the common electrode C0 is applied to the plurality of switch elements included in the control circuit. It may be determined by ON/OFF. When a ground voltage, a positive voltage, or a negative voltage is applied to the first individual electrode L1, the second individual electrode L2, and the common electrode C0, which paths and through which switch elements can be transmitted are shown in FIG. It may be indicated by a dotted line and an arrow.

Meanwhile, the paths of the dotted lines and arrows indicated on the circuit diagram of FIG. 20 are given as an example, and the first individual electrode L1, the second individual electrode L2, and the common A driving voltage may be transmitted to the electrode C0.

19 and 20, by applying voltages having opposite polarities to the first individual electrode L1 and the common electrode C0, a driving voltage twice the magnitude of the voltage applied to the electrode is applied to the liquid lens can make it happen Through this, when a driving voltage of about 70 V is required to control the movement of the interface included in the liquid lens, a voltage of about 35 V of different polarity is applied to the first individual electrode L1 and the common electrode C0 to approximately Substantially the same effect as that in which the driving voltage of 70V is applied can be obtained. A switching device that selectively transmits a lower voltage can be made smaller, thereby realizing the miniaturization of the control circuit and increasing the degree of integration.

The liquid lens described above may be included in the camera module. The camera module includes a lens assembly including a liquid lens mounted on a housing and at least one solid lens that can be disposed on the front or rear side of the liquid lens, an image sensor that converts an optical signal transmitted through the lens assembly into an electrical signal, and A control circuit for supplying a driving voltage to the liquid lens may be included.

Although only a few have been described as described above in relation to the embodiments, various other forms of implementation are possible. The technical contents of the above-described embodiments may be combined in various forms unless they are incompatible with each other, and may be implemented in a new embodiment through this.

An optical device including the above-described camera module may be implemented. Here, the optical device may include a device capable of processing or analyzing an optical signal. Examples of optical devices include camera/video devices, telescope devices, microscope devices, interferometer devices, photometric devices, polarimeter devices, spectrometer devices, reflectometer devices, autocollimator devices, lensmeter devices, etc., and may include liquid lenses. The embodiment of the present invention can be applied to optical devices capable of Also, the optical device may be implemented as a portable device such as a smart phone, a notebook computer, or a tablet computer. Such an optical device may include a camera module, a display unit for outputting an image, and a body housing on which the camera module and the display unit are mounted. The optical device may have a communication module capable of communicating with other devices mounted on the main housing and may further include a memory unit capable of storing data.

The method according to the above-described embodiment may be produced as a program to be executed by a computer and stored in a computer-readable recording medium, and examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape. , floppy disks, optical data storage devices, and the like.

The computer-readable recording medium is distributed in a network-connected computer system, so that the computer-readable code can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

It is apparent to those skilled in the art that the present invention may 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 restrictive in all respects but as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

Claims (18)

A method of controlling a liquid lens having a common electrode and a plurality of individual electrodes, the method comprising:
floating at least one individual electrode among the plurality of individual electrodes for a preset time while the voltage is applied to the common electrode when the driving voltage applied to the liquid lens is changed; and
re-applying a voltage to the at least one individual electrode after floating the at least one individual electrode;
The floating step is
generating a voltage by means of a voltage generator;
selectively switching and outputting the voltage or the ground voltage generated by the voltage generator by a first switching unit;
selectively switching and outputting a voltage output from the first switching unit by a second switching unit; and
A liquid lens control method for floating at least one of the plurality of individual electrodes by turning off the second switching unit for a preset time. The method of claim 1, wherein the floating step
A liquid lens control method for floating at least one of the two individual electrodes when a driving voltage between the two individual electrodes of the plurality of individual electrodes is different. The liquid lens control method according to claim 1, wherein the voltage is a first voltage, a second voltage, or a ground voltage. a liquid lens comprising a common electrode and a plurality of individual electrodes; and
a control circuit electrically connected to the common electrode and the individual electrode to control the liquid lens;
The control circuit is
When the driving voltage for driving the liquid lens is changed, floating at least one individual electrode among the plurality of individual electrodes in a state where a first voltage is applied to the common electrode,
The control circuit is
a voltage generator that outputs a voltage;
a first switching unit for selectively switching the voltage or the ground voltage output from the voltage generator; and
and a second switching unit for turning on/off the voltage output from the first switching unit,
The control circuit turns off the second switching unit for a preset time to float at least one of the plurality of individual electrodes. 5. The method of claim 4, wherein the control circuit is
A camera module for applying a second voltage to the at least one individual electrode after floating the at least one individual electrode. 5. The method of claim 4, wherein the voltage generator is
a first voltage generator; and
a second voltage generator;
The voltage output from the first voltage generator and the voltage output from the second voltage generator are different from each other. The method of claim 6, wherein the first switching unit
a first switch selectively transferring the voltage output from the first voltage generator;
a second switch selectively transferring the ground voltage;
a third switch selectively transferring the voltage output from the second voltage generator; and
A camera module including a fourth switch selectively transferring the ground voltage. The method of claim 7, wherein the second switching unit
a fifth switch selectively transferring the voltage transferred from the first switch or the second switch to the liquid lens; and
and a sixth switch selectively transferring the voltage transferred from the third switch or the fourth switch to the liquid lens. 9. The method of claim 8, wherein the control circuit is
A camera module configured to float the at least one individual electrode by simultaneously switching the fifth switch and the sixth switch. The camera module of claim 4 , wherein the control circuit floats the at least one individual electrode when driving voltages applied to at least two individual electrodes among the plurality of individual electrodes are different. The camera module of claim 4 , wherein the driving voltage is an effective voltage of a voltage applied between the common electrode and the individual electrode. 5. The method of claim 4,
The liquid lens
a first plate having a cavity for accommodating a conductive liquid and a non-conductive liquid;
a common electrode disposed on the first plate;
a plurality of individual electrodes disposed under the first plate;
a second plate disposed on the common electrode;
A camera module including a third plate disposed under the first plate. 5. The method of claim 4, wherein the change of the driving voltage is a change of the driving voltage from the first driving voltage to the second driving voltage,
A level of the second driving voltage is greater than a level of the first driving voltage. 5. The method of claim 4,
The plurality of individual electrodes includes first to fourth individual electrodes sequentially arranged in a circumferential direction,
At least one individual electrode of the plurality of individual electrodes floats when the driving voltage applied to the first individual electrode and the driving voltage applied to the third individual electrode are different from each other. The camera module of claim 5 , wherein after the floating, the first voltage and the second voltage are the same voltage. a liquid lens comprising a common electrode and a plurality of individual electrodes; and
a control circuit electrically connected to the common electrode and the plurality of individual electrodes to control the liquid lens;
The control circuit is
a first voltage generator for generating a first voltage; and
a second voltage generator for generating a second voltage different from the first voltage;
a first switching unit disposed between the first and second voltage generators and the individual electrodes; and
a second switching unit disposed between the first switching unit and the individual electrode;
When the driving voltage applied to the liquid lens is changed, the control circuit turns off the second switching unit for a preset time to float at least one of the plurality of individual electrodes,
The first switching unit
a first switch selectively transferring the first voltage;
a second switch selectively transferring a ground voltage;
a third switch selectively transferring the second voltage; and
a fourth switch selectively transferring the ground voltage;
The second switching unit
a fifth switch selectively transferring the voltage transferred from the first switch or the second switch to the liquid lens; and
and a sixth switch selectively transferring the voltage transferred from the third switch or the fourth switch to the liquid lens. The camera module of claim 16 , wherein the control circuit turns off the fifth switch and the sixth switch at the same time to turn off the second switch for a preset time. The method of claim 16, wherein the change of the driving voltage is a change of the driving voltage from the first driving voltage to the second driving voltage,
A level of the second driving voltage is greater than a level of the first driving voltage.

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