KR102362733B1 - Liquid lens, camera module, and optical apparatus - Google Patents

Abstract

A liquid lens according to an embodiment of the present invention includes: a conductive liquid and a non-conductive liquid accommodated in a cavity and forming an interface; and n individual electrodes (n is an integer greater than or equal to 2) and a common electrode for controlling the interface, wherein a first driving voltage applied between the common electrode and any one of the n individual electrodes is Controlled in units of a unit cycle including one sub-cycle and a second sub-cycle, the level of the first driving voltage in the first sub-cycle is a first voltage, and the level of the first driving voltage in the second sub-cycle may be the second voltage.

Description

LIQUID LENS, CAMERA MODULE, AND OPTICAL APPARATUS

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

Users of portable devices have high resolution, small size, and various shooting functions (optical zoom function (zoom-in/zoom-out), auto-focusing (AF) function, image stabilization or image stabilization (Optical Image Stabilizer, OIS) function, etc.) is desired. 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, so the overall thickness is increased.

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.

Publication No. 10-2009-0018965 (February 24, 2009)

An object of the present invention is to provide a liquid lens, a camera module, and an optical device capable of increasing resolution for auto-focusing without increasing power consumption.

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 liquid lens according to an embodiment of the present invention includes: a conductive liquid and a non-conductive liquid accommodated in a cavity and forming an interface; and n individual electrodes (n is an integer greater than or equal to 2) and a common electrode for controlling the interface, wherein a first driving voltage applied between the common electrode and any one of the n individual electrodes is Controlled in units of a unit cycle including one sub-cycle and a second sub-cycle, the level of the first driving voltage in the first sub-cycle is a first voltage, and the level of the first driving voltage in the second sub-cycle may be the second voltage.

According to an embodiment, the sum of the number of the first sub-cycles and the number of the second sub-cycles may be X (X is an integer greater than or equal to 2).

According to an embodiment, within one unit cycle, in each of the sub-cycles, the sum of driving voltages between each of the n individual electrodes and the common electrode may be constantly maintained.

According to an embodiment, when the number of the second sub-cycles among the X sub-cycles within one unit cycle is Y, the average driving voltage in the unit cycle may satisfy the following equation.

(Equation) Average driving voltage in unit cycle = first voltage + (preset unit driving voltage * Y) / X,

Here, preset unit driving voltage = second voltage - first voltage

According to an embodiment, when the first sub-cycle is changed to a second sub-cycle adjacent to the first sub-cycle, a level of a driving voltage of at least one of the n individual electrodes may be changed.

In some embodiments, the second voltage may be a sum of the first voltage and a preset unit voltage.

According to an embodiment, the first driving voltage may have two voltage levels.

In some embodiments, the second voltage may be higher than the first voltage.

The camera module according to an embodiment of the present invention is accommodated in a cavity, a conductive liquid and a non-conductive liquid forming an interface, and n individual electrodes (n is an integer greater than or equal to 2) for controlling the interface and common a liquid lens comprising an electrode; and a control circuit for controlling a voltage applied to the n individual electrodes and the common electrode, wherein a first driving voltage applied between the common electrode and any one of the n individual electrodes comprises a first sub-cycle and It is controlled in units of a unit cycle including a second sub-cycle, wherein in the first sub-cycle, the level of the first driving voltage is a first voltage, and in the second sub-cycle, the level of the first driving voltage is a second voltage can be

An optical device according to an embodiment of the present invention includes: a camera module; a display unit for outputting an image; a battery for supplying power to the camera module; and a housing in which the camera module, the display unit, and the battery are mounted.

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.

According to the method for applying a driving voltage of a liquid lens, a liquid lens, a camera module, and an optical device according to an embodiment of the present invention, autofocusing resolution can be increased by using a unit voltage in a constant output voltage range of a voltage driver.

In addition, while increasing the auto-focusing resolution, an increase in the output voltage range of the voltage driver is not required, thereby reducing power consumption of the optical device.

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 an example of a camera module according to an embodiment of the present invention.
2 illustrates an example of a lens assembly included in a camera module.
FIG. 3 is a block diagram schematically illustrating the camera module shown in FIG. 1 .
4 illustrates a liquid lens whose interface is adjusted in response to a driving voltage.
5 is a view for explaining an embodiment of the voltage supplied to both ends of the liquid lens.
6 is a view for explaining a method of applying a voltage to a liquid lens according to an embodiment of the present invention.
7 is a view for explaining a voltage application method of a liquid lens according to an embodiment of the present invention shown in FIG. 6 from the side of one driving electrode.
8 is a diagram for explaining an effect of a method of applying a driving voltage according to an embodiment of the present invention.
9 is a view for explaining a voltage application method of a liquid lens according to another embodiment of the present invention from the side of one driving electrode.
10 is a view for explaining an effect of a method of applying a driving voltage according to another embodiment of the present invention.

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 an example of a camera module according to an embodiment of the present invention.

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

The liquid lens may include a conductive liquid and a non-conductive liquid, a first plate, and an electrode part. The first plate may include a cavity for receiving a conductive liquid and a non-conductive liquid. The electrode unit may be electrically connected to an external power source to change an interface between the conductive liquid and the non-conductive liquid by applying a voltage. The liquid lens may further include an insulating layer disposed on the electrode part to block contact between the electrode and the non-conductive liquid.

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

The lens assembly 22 may include a plurality of lenses. The lens assembly 22 may include a plurality of lenses including a liquid lens, and a focal length of the liquid lens may be adjusted in response to a driving voltage applied to the first electrode and the second electrode. The camera module 22 may further include a control circuit 24 for supplying a driving voltage to the liquid lens. The first electrode may be an individual electrode, and the second electrode may be a conductive metal plate or a common electrode. Here, the first electrode may be n (n is an integer greater than or equal to 2) individual electrodes.

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

2 illustrates an example of the lens assembly 22 included in the camera module 10 .

The camera module 10 may be included in an optical device. The optical device may include a housing in which at least one of a camera module, a display unit, a communication module, a memory storage unit, and a battery is mounted.

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

The connection unit 500 may be one or two or more. For example, in the case of having one connection part, a part of the connection part is disposed on the upper or lower part of the liquid lens 300 to be connected to the liquid lens 300, and when it has two connection parts, it is connected to the upper part of the liquid lens 300 It may include a first connection part and a second connection part connected to the lower portion of the liquid lens. One end of the connection part may be disposed under the lens assembly 22 and may be electrically connected to a substrate on which the image sensor 26 on which the image sensor is mounted is disposed. 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 an optical device. For example, in the illustrated example, the liquid lens 300 is positioned between the first lens unit 100 and the second lens unit 200, but in other examples, the first lens unit or the second lens unit may be omitted. . In addition, the liquid lens 300 may be located above the first lens unit 100 (front), and the liquid lens 300 may be located below the second lens unit. The liquid lens 300 includes a cavity defined by an aperture area, and in the other example, the liquid lens 300 may be disposed so that the inclination direction of the cavity 310 is opposite. This may mean that, unlike FIG. 2 , the opening area of the cavity 310 in the direction in which the light is incident is narrower than the opening area in the opposite direction. When the liquid lens 300 is disposed so that the inclination direction of the cavity 310 is opposite, all or part of the arrangement of the liquid lens such as the electrode and the liquid may be changed together depending on the liquid lens inclination direction, and the inclination direction of the cavity may be changed and the rest of the batch may not be changed.

The first lens unit 100 is disposed in front of the lens assembly 22 , and is configured to receive light from the outside of the lens assembly 22 . The first lens unit 100 may include 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 holder 400 . In this case, a through hole may be formed in the holder 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 300 may be inserted into the space between the first lens unit 100 and the second lens unit 200 in the holder 400 .

Meanwhile, the first lens unit 100 may include an exposure lens 110 . The exposure lens 110 refers to a lens that can be exposed to the outside by protruding to the outside of the holder 400 . 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.

The second lens unit 200 is disposed behind the first lens unit 100 and the liquid lens 300 , and light incident to the first lens unit 100 from the outside passes through the liquid lens unit 300 , It may 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 holder 400 .

Meanwhile, the second lens unit 200 may include 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 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 holder 400 . The liquid lens 300 may also be aligned with respect to the central axis PL like the first lens unit 100 and the second lens unit 200 . One or at least two insertion holes 410 of the holder 400 may be formed on the side of the holder 400 . The liquid lens may be disposed in the insertion hole 410 . The liquid lens may be disposed to protrude to the outside of the insertion hole 410 .

The liquid lens 300 may include a cavity 310 . The cavity 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 cavity 310 may contain two types, namely, a conductive liquid and a non-conductive liquid (or an insulating liquid), and the conductive liquid and the non-conductive liquid may form an interface without mixing with each other. The interface between the conductive liquid and the non-conductive liquid may be deformed by the driving voltage applied through the connection part 500 to change the curvature and/or focal length of the liquid lens 300 . When the deformation of the boundary surface and the change in curvature are controlled, the liquid lens 300 and the lens assembly 22 and the optical device including the same are auto-focusing (Auto-Focusing; AF) function, hand shake correction or image stabilizer (Optical Image Stabilizer) , OIS) functions, and the like.

FIG. 3 is a block diagram schematically illustrating the camera module shown in FIG. 1 .

Referring to FIG. 3 , the control circuit 210 and the lens assembly 250 included in the camera module 200 are shown, and each of the control circuit 210 and the lens assembly 250 is the control circuit 24 of FIG. 1 . ) and the lens assembly 22 .

The control circuit 210 may include a control unit 220 .

The control unit 220 is a configuration for performing the AF function and the OIS function, and the liquid lens ( 260) can be controlled.

The controller 220 may include a controller 230 and a voltage driver 235 . The gyro sensor 225 may be an independent configuration that is not included in the controller 220 , and the controller 220 may further include the gyro sensor 225 .

The gyro sensor 225 may detect an angular velocity of movement in two directions of a yaw axis and a pitch axis in order to compensate for hand shake in the vertical and horizontal directions of the optical device 200 . The gyro sensor 225 may generate a motion signal corresponding to the sensed angular velocity and provide it to the controller 230 .

The controller 230 removes a high-frequency noise component from a motion signal using a low-pass filter (LPF) to implement the OIS function, extracts only a desired band, and uses the noise-removed motion signal to shake hand. In order to calculate the amount, and to compensate for the calculated amount of hand shake, a driving voltage corresponding to the shape that the liquid lens 280 of the liquid lens 260 should have may be calculated.

The controller 230 may receive information for the AF function (ie, distance information with an object) from the inside (eg, image sensor) or outside (eg, distance sensor) of the optical device or camera module 200, A driving voltage corresponding to a shape that the liquid lens 280 should have may be calculated according to a focal length for focusing on the object through distance information.

The controller 230 may store a driving voltage table in which a driving voltage and a driving voltage code for causing the voltage driver 235 to generate the driving voltage are mapped, and convert the driving voltage code corresponding to the calculated driving voltage to the driving voltage. It can be obtained by referring to the table.

The voltage driver 235 may generate an analog driving voltage corresponding to the driving voltage code based on the digital driving voltage code provided from the controller 230 and provide it to the lens assembly 250 .

The voltage driver 235 receives a supply voltage (eg, a voltage supplied from a separate power circuit) and increases the voltage level. Each of a voltage stabilizer and liquid lens 280 for stabilizing the output of the voltage booster A switching unit for selectively supplying an output of the voltage booster to a terminal may be included.

Here, the switching unit may include a configuration of a circuit called an H bridge. The high voltage output from the voltage booster is applied as a power supply voltage of the switching unit. The switching unit may selectively supply the applied power voltage and ground voltage to both ends of the liquid lens 280 . Here, the liquid lens 280 may include a first electrode including four electrode sectors and a second electrode including one electrode sector for driving, and both ends of the liquid lens 280 are connected to the first electrode and It may mean a second electrode. Also, both ends of the liquid lens 280 may refer to any one of four electrode sectors of the first electrode and one electrode sector of the second electrode.

A voltage in the form of a pulse having a preset width may be applied to each electrode sector of the liquid lens 280 , and the driving voltage applied to the liquid lens 280 is the difference between the voltages applied to each of the first electrode and the second electrode. to be. Here, a voltage applied to the first electrode may be defined as an individual voltage, and a voltage applied to each electrode sector of the second electrode may be defined as an individual voltage.

That is, in order for the voltage driver 235 to control the driving voltage applied to the liquid lens 280 according to the digital driving voltage code provided from the controller 230 , the voltage booster controls the increased voltage level, The switching unit generates an analog driving voltage corresponding to the driving voltage code by controlling the phases of the pulse voltages applied to the common electrode and the individual electrodes.

That is, the controller 220 may control the voltage applied to each of the first electrode and the second electrode.

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

In addition, the connector may receive power from an external (eg, battery) to supply power required for the operation of the controller 220 and the lens assembly 250 .

The lens assembly 250 may include a liquid lens module 260 , and the liquid lens module 260 may include a driving voltage providing unit 270 and a liquid lens 280 .

The driving voltage providing unit 270 receives a driving voltage (ie, an analog voltage applied between any one of the four individual electrodes and one common electrode) from the voltage driver 235 and receives the liquid lens 280 . A driving voltage may be provided. The driving voltage providing unit 270 may include a voltage adjusting circuit or a noise removing circuit for compensating for a loss due to the terminal connection between the control circuit 210 and the lens assembly 250, or bypassing the output voltage. bypass) is also possible.

The driving voltage providing unit 260 may be disposed on a flexible printed circuit board (FPCB, or a first board) constituting at least a portion of the connection unit 500 of FIG. 2 , but the scope of the present invention is not limited thereto. The connection unit 500 may include a driving voltage providing unit 260 .

The liquid lens 280 may perform an AF function or an OIS function by deforming the interface between the conductive liquid and the non-conductive liquid according to the driving voltage.

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

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

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

In the present specification, four different electrode sectors are described as an example, but the scope of the present invention is not limited thereto.

5 is a view for explaining an embodiment of the voltage supplied to both ends of the liquid lens.

Referring to FIG. 5 , a voltage in the form of a pulse having a preset width may be applied to each electrode sector C0 and L1 to L4 of the liquid lens 280, and each electrode sector L1 to L4 of the first electrode. and the voltage difference between the electrode sector C0 of the second electrode becomes the driving voltage.

The voltage driver 235 may control the driving voltage corresponding to each individual electrode by controlling the phases of the pulse voltages applied to the common electrode sector and the individual electrode sectors.

In FIG. 5 , the voltage driver 235 may shift the phase of the pulse voltage according to an operation clock provided from the outside, the first pulse voltage A applied to the individual electrode sector L1 and The second pulse voltage B is shown. The second pulse voltage B is a voltage obtained by delaying the first pulse voltage A by a minimum phase.

Compared to the driving voltage 1 when the first pulse voltage A is applied to the individual electrode sector L1 , the driving voltage of the driving voltage 2 when the second pulse voltage B is applied to the individual electrode sector L1 . It can be seen that this is higher. Here, the RMS (Root Mean Square) value of the driving voltage directly contributes to the control of the interface of the liquid lens 280 .

The minimum phase is determined by the frequency of the operating clock provided by the voltage driver 235 . The minimum phase may determine the resolution of the output voltage of the voltage driver 235 , and as the minimum phase is smaller, the resolution of the output voltage of the voltage driver 235 may be increased.

However, if the resolution of the output voltage of the voltage driver 235 is to be doubled, the voltage driver 235 must receive the operating clock of the doubled frequency, so a high-performance clock generator is required. Since this causes significant losses in terms of cost and power consumption from the viewpoint of the entire system, a method capable of increasing the resolution of the output voltage of the voltage driver 235 without a high-performance clock generator is required.

6 is a view for explaining a method of applying a voltage to a liquid lens according to an embodiment of the present invention.

Referring to FIG. 6 , the driving voltage application method in FIG. 6 or less is mainly described for providing the auto-focusing function, but the scope of the present invention is not limited thereto, and the same technical idea is used even when the OIS function is provided. can be In addition, the voltage level and timing of the voltage applied to the liquid lens described below with reference to FIG. 6 may be controlled by a driving voltage code generated by the controller 230 .

Four liquid lenses are shown for each cycle (CYCLE1-4), and an electrode sector located on the upper left side of the first electrodes of one liquid lens is defined as a first electrode sector, and the center (or optical axis or Electrode sectors sequentially positioned in a clockwise direction from the first electrode sector based on the circumference) are defined as a second electrode sector, a third electrode sector, and a fourth electrode sector, respectively.

In addition, each of the first to fourth driving electrodes means a pair of a corresponding individual electrode sector among the first to fourth electrode sectors and a common electrode sector of the second electrode, and a driving voltage applied to the first to fourth driving electrodes are defined as first to fourth driving voltages, respectively.

The first to fourth driving voltages correspond to voltage differences between the first to fourth voltages applied to the first to fourth electrode sectors and the voltages applied to the second electrode, respectively. The first to fourth driving voltages may mean an average value or RMS value of the voltage difference within one cycle.

In addition, a unit cycle for deforming the interface of the liquid lens may be defined, and the first to fourth cycles CYCLE1 to CYCLE4 shown in FIG. 5 correspond to this.

The time corresponding to the unit cycle may be determined in consideration of an auto focusing response time, that is, a time taken for the liquid lens to be transformed into a desired interface after the driving voltage is applied. The auto-focusing reaction time may vary depending on the specification of the liquid lens, but the auto-focusing reaction time may have a reaction time of about 50 ms or so, and thus the unit cycle may be determined in consideration of the auto-focusing reaction time and the number of sub-cycles. .

The controller 230 of FIG. 3 calculates the driving voltage and transmits the driving voltage code to the voltage driver 235. At this time, it can be transmitted through the bidirectional serial data port (SDA) and the clock port (SCL) in the I²C method, and the maximum It can support 1Mhz.

The voltage driver 235 generates a driving voltage corresponding to the driving voltage code based on the driving voltage code received from the controller 230, and the driving voltage is applied to each capacitor 30 shown in FIG. It includes first to fourth driving voltages indicating both ends of the voltage, and for application of the driving voltage, substantially first to fourth electrode sector voltages of the second electrode and voltages of the second electrode may be generated.

The first to fourth driving voltages have a maximum output voltage, a minimum output voltage, and a constant unit voltage according to the structure of the voltage driver 235 , and the maximum output voltage and the minimum output voltage are the maximum and minimum output voltages of the voltage driver 235 . It means a possible voltage, and the unit voltage means a voltage capable of minimum increasing or decreasing each of the first to fourth driving voltages. The unit voltage may be determined by the minimum phase determined according to the frequency of the operation clock when the voltage driver 235 adjusts the output voltage in a manner that shifts the phase of the pulse voltage according to the operation clock.

However, each of the first to fourth driving voltages does not have to be increased or decreased by 1V, but may be increased or decreased by 10V, for example.

For example, when the maximum output voltage is 70V, the minimum output voltage is 41V, and the unit voltage is 1V, the first to fourth individual voltages may have 30 voltages within a range of 41V to 70V, respectively.

That is, assuming that the same driving voltage is applied to the first to fourth driving electrodes for the auto-focusing function, 30 steps of auto-focusing resolution may be implemented.

In this case, the k-th driving voltage Vk (k is an integer greater than or equal to 1 and less than or equal to N; N is an integer greater than or equal to 2) is expressed by Equation 1 below. Here, the k-th driving voltage means an arbitrary driving voltage when the minimum output voltage is the first driving voltage and the maximum output voltage is the N-th driving voltage.

[Equation 1]

Vk=Vi+dv*k

Here, Vi denotes a minimum output voltage, and dv denotes a unit voltage.

Accordingly, if the same driving voltage is applied to the first to fourth driving electrodes within a constant output voltage range (the range between the maximum output voltage and the minimum output voltage), the unit voltage for the driving voltage is the unit voltage of the voltage driver 235 . , and the auto-focusing resolution depends on the unit voltage of the voltage driver 235 . The auto-focusing resolution is the most important factor influencing the performance of the auto-focusing function because it is a criterion that determines the degree of fine-tuning the auto-focusing function.

Hereinafter, a method of applying a driving voltage capable of increasing auto-focusing resolution within a certain output voltage range will be described.

Although not shown in FIG. 6 , in the initial cycle before the first cycle CYCLE1, the individual voltages applied to the first to fourth electrode sectors are respectively V (V is an arbitrary voltage within the output voltage range, hereinafter 'initial voltage') ') is assumed.

As shown in FIG. 6 , each cycle CYCLE1 to CYCLE4 may be divided into a total of four subcycles. The time of each subcycle may be the same or different from each other. In an embodiment in which the time of each sub-cycle is the same, if each cycle CYCLE 1 to CYCLE 4 has a time of 50 ms, the time of each sub-cycle may be 12.5 ms. A voltage applied to each driving electrode may be maintained within one sub-cycle. According to another exemplary embodiment, a voltage applied to each driving electrode within one sub-cycle may be varied. For example, in the second cycle CYCLE2, the first and second cycles and the third and fourth cycles may each be defined as constituting one subcycle. In this case, the time of each sub-cycle may be 25 ms.

(V+dv, V, V, V) in the first sub-cycle of the first cycle (CYCLE1), (V, V+dv, V, V) in the second sub-cycle, (V, V+dv, V, V) in the third sub-cycle V, V, V+dv, V) and (V, V, V, V+dv) may be applied in the fourth sub-cycle. Here, a, b, c, and d in (a, b, c, d) mean first to fourth driving voltages, respectively.

That is, in the first sub-cycle of the first cycle CYCLE1, any one of the first to fourth driving voltages is increased by a unit voltage from the initial voltage (V+dv, hereinafter referred to as a 'second voltage') ) and the remaining driving voltage may be applied as an initial voltage (V, hereinafter referred to as a 'first voltage'). In a subsequent subcycle, the position at which the second voltage is sequentially applied in a clockwise direction may be changed. Here, the driving electrode to which the second voltage is applied is indicated by a shade, and the clockwise direction is only an example, and it goes without saying that the driving electrode may be set in a counterclockwise direction, a zigzag direction, or the like.

In this specification, the meaning of applying any one of the first to fourth driving voltages as the first voltage or the second voltage in any one sub-cycle means that the level of the one driving voltage is the first voltage or It may mean to become the second voltage. Here, in any one unit cycle, the first to fourth driving voltages may have two voltage levels, but the scope of the present invention is not limited thereto.

Also, the second voltage may be higher than the first voltage.

However, the positions to which the second voltage is applied in each subcycle should be set differently, because if the second voltage is continuously applied to any one position, the interface of the liquid lens may be distorted.

The driving voltage applied to any one driving electrode in one cycle corresponds to an average of the driving voltages applied in four sub-cycles.

Accordingly, the first to fourth driving voltages applied in the first cycle CYCLE1 correspond to (4V+dv)/4=V+dv/4.

(V+dv, V, V+dv, V) in the first sub-cycle of the second cycle CYCLE2, (V, V+dv, V, V+dv) in the second sub-cycle, the third sub-cycle (V+dv, V, V+dv, V) may be applied in the cycle, and (V, V+dv, V, V+dv) may be applied in the fourth sub-cycle.

That is, in the first sub-cycle of the second cycle CYCLE2 , any two of the first to fourth driving voltages may be applied as the second voltage and the remaining driving voltages may be applied as the first voltage. In the second subcycle, a driving voltage at a position to which the first voltage was applied may be applied as the second voltage, and a driving voltage at a position to which the second voltage was applied may be applied as the first voltage. In subsequent sub-cycles, the driving voltage application method of the first sub-cycle and the second sub-cycle may be repeated. Similarly to the sub-cycle of the first cycle CYCLE1 , the second cycle CYCLE2 may change the voltage application position in a clockwise or counterclockwise direction.

As shown in FIG. 6 , the driving voltages corresponding to the opposing positions are set to be the same, and the positions to which the second voltage is applied in the adjacent subcycles should be set differently from each other, in order to prevent the interface of the liquid lens from being distorted. Also, although not shown in the drawings, the voltage application may be controlled in a clockwise or counterclockwise direction by applying a first voltage to two adjacent electrode sectors among the four electrode sectors and a second voltage to the remaining electrode sectors.

In other words, when changing from one sub-cycle to another sub-cycle adjacent to the sub-cycle, the level of the driving voltage of at least one of the plurality of individual electrodes may be changed.

The first to fourth driving voltages applied in the second cycle CYCLE2 correspond to (4V+2dv)/4=V+dv/2.

In the first sub-cycle of the third cycle (CYCLE3) (V+dv, V+dv, V+dv, V), in the second sub-cycle, (V, V+dv, V+dv, V+dv) In the third sub-cycle, (V+dv, V, V+dv, V+dv) may be applied, and in the fourth sub-cycle, (V+dv, V+dv, V, V+dv) may be applied.

That is, in the first sub-cycle of the third cycle CYCLE3 , any three of the first to fourth driving voltages may be applied as the second voltage and the remaining driving voltages may be applied as the first voltage. In a subsequent subcycle, a position at which the first voltage is sequentially applied in a clockwise direction may be changed. Here, the clockwise direction is only an example, and of course, it may be set to a counterclockwise direction, a zigzag direction, or the like.

However, the positions to which the first voltage is applied in each subcycle should be set differently, because if the first voltage is continuously applied to any one position, the interface of the liquid lens may be distorted.

Accordingly, the first to fourth driving voltages applied in the third cycle CYCLE3 correspond to (4V+3dv)/4=V+3dv/4.

In the first sub-cycle of the fourth cycle (CYCLE4) (V+dv, V+dv, V+dv, V+dv), in the second sub-cycle, (V+dv, V+dv, V+dv, V+dv) is (V+dv, V+dv, V+dv, V+dv) in the third sub-cycle, (V+dv, V+dv, V+dv, V+) in the fourth sub-cycle dv) may be authorized.

That is, in the first to fourth sub-cycles of the fourth cycle CYCLE3 , all of the first to fourth driving voltages may be applied as the second voltages.

Accordingly, the first to fourth driving voltages applied in the fourth cycle CYCLE4 correspond to (4V+4dv)/4=V+dv.

In this case, within one unit cycle, the sum total of the first to fourth driving voltages applied in each sub-cycle may be kept constant, which is why the sum of the first to fourth driving voltages is maintained constant within one cycle. This is because a specific focal length must be maintained in the cycle.

In the case of the driving voltage application method according to the embodiment of the present invention, the k-th individual voltage V'k is expressed by Equation 2 below.

[Equation 2]

V'k=Vi+dv/4*k

Here, Vi denotes a minimum output voltage, and dv denotes a unit voltage.

Accordingly, the first to fourth driving voltages are not applied as the same driving voltage within a constant output voltage range, and after a cycle in which all of the first to fourth driving voltages are set to the first voltage, among the first to fourth driving voltages A cycle of setting only one voltage as the second voltage and rotating the driving voltage set as the second voltage, setting only two of the first to fourth driving voltages as the second voltage and rotating the driving voltage set as the second voltage By further inserting a cycle of setting only three voltages among the first to fourth driving voltages as the second voltage and rotating the driving voltage set as the second voltage, the unit voltage for determining the autofocusing resolution is changed from dv to dv/4. can be changed to

That is, when the unit voltage is reduced to 1/4, it means that the auto-focusing resolution is increased by 4 times, and the performance of the auto-focusing function can be remarkably improved.

For example, since the maximum output voltage is 70V, the minimum output voltage is 41V, and the unit voltage is 0.25V, the first to fourth driving voltages may have 120 voltages within the range of 41V to 70V, respectively. .

According to another embodiment, it is also possible to use only some of the cycles shown in FIG. 5 , for example, when only the voltage application method according to the second cycle CYCLE2 among the first to third cycles CYCLE1 to 3 is used. The resolution of the auto-focusing function can be doubled.

Also, in this specification, a sub-cycle in which the level of the first driving voltage becomes the first voltage may be defined differently as the first sub-cycle, and the sub-cycle in which the level of the second driving voltage becomes the second voltage may be defined differently as the second sub-cycle. have.

7 is a view for explaining the voltage application method of the liquid lens according to the embodiment of the present invention shown in FIG. 6 from the side of one driving electrode.

Referring to FIG. 7 , the driving voltage applied to the driving electrode corresponding to the first electrode sector L1 in each cycle CYCLE0 to CYCLE4 is illustrated.

The driving voltage indicated in white indicates a section to which the first voltage V is applied, and the driving voltage indicated in gray shade is shifted by the minimum phase in which the voltage applied to the first electrode sector L1 is shifted by the first voltage ( It means a section in which the second voltage (V+dv) in which the unit voltage is increased from V) is applied.

Each cycle CYCLE0 to CYCLE4 may be divided into four sub-cycles SUB1 to SUB4.

In the initial cycle CYCLE0, the first voltage V may be applied to the first driving electrode in the entire sub-cycles SUB1 to SUB4. Accordingly, the first driving voltage applied to the first driving electrode in the initial cycle CYCLE0 corresponds to V .

In the first cycle CYCLE1, the second voltage V+vd is applied to the first driving electrode in one sub-cycle SUB1 of the entire sub-cycles SUB1 to SUB4, and in the remaining sub-cycles SUB2 to SUB4 A first voltage V may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the first cycle CYCLE1 corresponds to V+dv/4.

In the second cycle CYCLE2, the second voltage V+vd is applied to the first driving electrode in two sub-cycles SUB1 and SUB2 among the entire sub-cycles SUB1 to SUB4, and the remaining sub-cycles SUB3 and SUB3 ) at the first voltage (V) may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the second cycle CYCLE1 corresponds to V+dv/2.

In the third cycle CYCLE3, the second voltage V+vd is applied to the first driving electrode in three sub-cycles SUB1 to SUB3 among the entire sub-cycles SUB1 to SUB4, and in the remaining sub-cycles SUB4 A first voltage V may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the third cycle CYCLE3 corresponds to V+3dv/4.

In the fourth cycle CYCLE4 , the second voltage V+dv may be applied to the first driving electrode in the entire sub-cycles SUB1 to SUB4 . Accordingly, the first driving voltage applied to the first driving electrode in the fourth cycle CYCLE4 corresponds to V+dv.

Here, in the cycles ( CYCLE1 to CYCLE3 ) in which different driving voltages are applied to each driving electrode, the number of sub-cycles to which the first voltage and the second voltage are applied to any one driving electrode should be the same for all driving electrodes. However, whether the first voltage and the second voltage are applied to any one driving electrode in any sub-cycle among a plurality of sub-cycles may be determined by various methods.

For example, as illustrated in the description of FIG. 6 , the position of the driving electrode to which the first voltage or the second voltage is applied in an adjacent subcycle may move in a clockwise direction, a counterclockwise direction, or a zigzag direction.

In addition, the position of the sub-cycle to which the second voltage is applied to the first driving electrode is slightly different from that of FIG. 6 , but this is for convenience of description and does not depart from the scope of the technical spirit of the present invention.

8 is a view for explaining an effect of a method of applying a driving voltage according to an embodiment of the present invention.

Referring to FIG. 8 , the average voltage applied to the electrode sector in each cycle CYCLE0 to 4 described in FIGS. 6 and 7 is illustrated.

The average voltage applied to the first to fourth driving electrodes in the initial cycle CYCLE0 is V, and the average voltage applied to the first to fourth driving electrodes in the first cycle CYCLE1 is V+dv/4, The average voltage applied to the first to fourth driving electrodes in the second cycle CYCLE2 is V+dv/2, and the average voltage applied to the first to fourth driving electrodes in the third cycle CYCLE3 is V+3dv/ 4, and the average voltage applied to the first to fourth driving electrodes in the fourth cycle CYCLE4 is V+dv.

That is, when the driving voltage is sequentially increased in each cycle, the unit voltage dv/4 may be increased, which corresponds to a value reduced to 1/4 compared to the unit voltage dv of the voltage driver 235 .

That is, when the same driving voltage is applied to the first to fourth driving electrodes, the unit voltage for the driving voltage that determines the autofocusing resolution becomes the same as the unit voltage of the voltage driver 235 , and as shown in FIG. 8 , V When going from the initial cycle (CYCLE0) to the first cycle (CYCLE1) in which the driving voltage of have.

However, in the case of the driving voltage application method shown in FIGS. 6 and 7 , the unit voltage for the driving voltage that determines the autofocusing resolution becomes 1/4 of the unit voltage of the voltage driver 235 , and in FIG. 8 , As shown, when going from the initial cycle (CYCLE0) in which the driving voltage of V is applied to the first cycle (CYCLE1), to sequentially increase the driving voltage, a driving voltage of V+dv/4 can be applied immediately, and V+ It may have four steps to apply the driving voltage of dv. That is, the method according to an embodiment of the present invention may have 4 times the auto-focusing resolution.

In the present specification, a case in which the liquid lens has 4 individual electrodes is described, but the scope of the present invention is not limited thereto, and may be applied to a case in which 8, 16, etc. individual electrodes are provided.

For example, if the liquid lens has 8 individual electrodes, one cycle may be divided into 8 sub-cycles, and the driving voltage may be applied in a manner that sequentially increases the number of individual electrodes to which the second voltage is applied. can In this case, the unit voltage with respect to the driving voltage may be 1/8 of the unit voltage of the voltage driver 235 , and thus the auto-focusing resolution may be increased by 8 times.

When this driving voltage application method is generalized, in addition to the cycle of applying the first to p-th driving voltages corresponding to the first to p-th driving electrodes (p is an integer greater than or equal to 2) as the first voltage or the second voltage, the first Auto-focusing resolution may be increased by adding p-1 cycles of applying q (q is an integer greater than or equal to 1 p-1) number of driving voltages as the second voltage among the 1 to p-th driving voltages.

In addition, in a cycle in which q driving voltages among the first to pth driving voltages are applied as the second voltage, the second voltage may be applied to any one driving electrode in q subcycles.

As described above, according to the driving voltage application method according to the present invention, autofocusing resolution can be increased by reducing the unit voltage for the driving voltage in a constant output voltage range of the voltage driver.

In addition, while increasing the auto-focusing resolution, an increase in the output voltage range of the voltage driver is not required, thereby reducing power consumption of the optical device.

9 is a view for explaining a voltage application method of a liquid lens according to another embodiment of the present invention from the side of one driving electrode.

Referring to FIG. 9 , the driving voltage applied to the driving electrode corresponding to the first electrode sector L1 in each cycle CYCLE0 to CYCLE6 is illustrated.

The driving voltage indicated in white indicates a section to which the first voltage V is applied, and the driving voltage indicated in gray shade is shifted by the minimum phase in which the voltage applied to the first electrode sector L1 is shifted by the first voltage ( It means a section in which the second voltage (V+dv) in which the unit voltage is increased from V) is applied.

Each cycle CYCLE0 to CYCLE6 may be divided into six subcycles SUB1 to SUB6.

In the initial cycle CYCLE0, a first voltage V may be applied to the first driving electrode in the entire sub-cycles SUB1 to SUB6. Accordingly, the first driving voltage applied to the first driving electrode in the initial cycle CYCLE0 corresponds to V .

In the first cycle CYCLE1, the second voltage V+vd is applied to the first driving electrode in one sub-cycle SUB1 of the entire sub-cycles SUB1 to SUB6, and in the remaining sub-cycles SUB2 to SUB6 A first voltage V may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the first cycle CYCLE1 corresponds to V+dv/6.

In the second cycle CYCLE2, the second voltage V+vd is applied to the first driving electrode in two sub-cycles SUB1 and SUB2 among the entire sub-cycles SUB1 to SUB6, and the remaining sub-cycles SUB3 to SUB6 ) at the first voltage (V) may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the second cycle CYCLE1 corresponds to V+dv/3.

In the third cycle CYCLE3, the second voltage V+vd is applied to the first driving electrode in three sub-cycles SUB1 to SUB3 among the entire sub-cycles SUB1 to SUB6, and the remaining sub-cycles SUB4 to SUB6 ) at the first voltage (V) may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the third cycle CYCLE3 corresponds to V+dv/2.

In the fourth cycle CYCLE4, the second voltage V+vd is applied to the first driving electrode in four sub-cycles SUB1 to SUB4 among the entire sub-cycles SUB1 to SUB6, and the remaining sub-cycles SUB5 and SUB6 ) at the first voltage (V) may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the fourth cycle CYCLE4 corresponds to V+2dv/3.

In the fifth cycle CYCLE5, the second voltage V+vd is applied to the first driving electrode in five sub-cycles SUB1 to SUB5 of the entire sub-cycle SUB1 to SUB6, and in the remaining sub-cycles SUB6 A first voltage V may be applied. Accordingly, the first driving voltage applied to the first driving electrode in the fifth cycle CYCLE5 corresponds to V+5dv/6.

In the sixth cycle CYCLE6, the second voltage V+dv may be applied to the first driving electrode in the entire sub-cycle SUB1 to SUB6. Accordingly, the first driving voltage applied to the first driving electrode in the sixth cycle CYCLE6 corresponds to V+dv.

Here, in the cycles CYCLE1 to CYCLE5 in which different driving voltages are applied to each driving electrode, the number of sub-cycles to which the first voltage and the second voltage are applied to any one driving electrode should be the same for all driving electrodes. However, whether the first voltage and the second voltage are applied to any one driving electrode in any sub-cycle among a plurality of sub-cycles may be determined by various methods.

For example, as illustrated in the description of FIG. 6 , the position of the driving electrode to which the first voltage or the second voltage is applied in an adjacent subcycle may move in a clockwise direction, a counterclockwise direction, or a zigzag direction.

In addition, when the total number (4) of the driving electrodes to which the second voltage or the first voltage is applied is less than the number (6) of sub-cycles, such as in the first cycle (CYCLE1) or the fifth cycle (CYCLE5), In at least two sub-cycles, the first voltage or the second voltage may be equally applied to the four driving electrodes, and the positions of these sub-cycles may be arbitrarily determined to minimize deformation of the interface.

10 is a view for explaining an effect of a method of applying a driving voltage according to another embodiment of the present invention.

Referring to FIG. 10 , the average voltage applied to the electrode sector in each cycle CYCLE0 to 6 described in FIG. 9 is shown.

The average voltage applied to the first to fourth driving electrodes in the initial cycle CYCLE0 is V, and the average voltage applied to the first to fourth driving electrodes in the first cycle CYCLE1 is V+dv/6, The average voltage applied to the first to fourth driving electrodes in the second cycle CYCLE2 is V+dv/3, and the average voltage applied to the first to fourth driving electrodes in the third cycle CYCLE3 is V+dv/ 2, the average voltage applied to the first to fourth driving electrodes in the fourth cycle CYCLE4 is V+2dv/3, and the average voltage applied to the first to fourth driving electrodes in the fifth cycle CYCLE3 is V+5dv/6, and the average voltage applied to the first to fourth driving electrodes in the sixth cycle CYCLE6 is V+dv.

That is, when the driving voltage is sequentially increased in each cycle, the unit voltage dv/6 may be increased, which corresponds to a value reduced to 1/6 compared to the unit voltage dv of the voltage driver 235 .

That is, when the same driving voltage is applied to the first to fourth driving electrodes, the unit voltage for the driving voltage that determines the autofocusing resolution becomes the same as the unit voltage of the voltage driver 235 , and as shown in FIG. 10 , V When going from the initial cycle (CYCLE0) to the first cycle (CYCLE1) in which the driving voltage of have.

However, according to the method of applying the driving voltage shown in FIG. 9 , the unit voltage for the driving voltage that determines the autofocusing resolution becomes 1/6 of the unit voltage of the voltage driver 235 , and as shown in FIG. 10 , V When going from the initial cycle (CYCLE0) to the first cycle (CYCLE1) of applying the driving voltage of It can have six steps for applying the voltage. That is, the method according to an embodiment of the present invention may have six times the auto-focusing resolution.

In this specification, only the case where the unit cycle for controlling the liquid lens is divided into 4 or 6 sub-cycles has been described, but the scope of the present invention is not limited thereto, and the unit cycle may be divided into 8 and 10 sub-cycles. can

That is, by dividing one unit cycle into X (where X is an integer greater than or equal to 2) subcycles and varying the number of subcycles to which the second voltage is applied to one driving electrode, the unit voltage for the driving voltage is set by the voltage driver 235 ) can be 1/X of the unit voltage, whereby the autofocusing resolution can be increased by X times.

In other words, when a unit cycle is divided into X sub-cycles and a second voltage is applied to one driving electrode in Y sub-cycles, the driving voltage in the corresponding unit cycle may be V+Y*dv/X. That is, in one unit cycle, if the number of the second subcycles among the X subcycles is Y, the average driving voltage in the unit cycle may satisfy Equation 3 below.

[Equation 3]

Average driving voltage in unit cycle = first voltage + (preset unit driving voltage * Y) / X

Here, the preset unit driving voltage may be a value obtained by subtracting the first voltage from the second voltage, and may mean a minimum controllable unit driving voltage of the voltage driver, but the scope of the present invention is not limited thereto.

Equation 3 can be expressed differently as Equation 4 above.

[Equation 4]

Average driving voltage in unit cycle = (first voltage * (x-y) + second voltage * y) / x

As described above, according to the driving voltage application method according to the present invention, autofocusing resolution can be increased by reducing the unit voltage for the driving voltage in a constant output voltage range of the voltage driver.

In addition, while increasing the auto-focusing resolution, an increase in the output voltage range of the voltage driver is not required, thereby reducing power consumption of the optical device.

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.

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.

For example, it is possible to implement an optical device (Optical Device, Optical Instrument) including a camera module including the aforementioned liquid lens. 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 an optical device capable of In addition, 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.

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 (10)

a conductive liquid and a non-conductive liquid accommodated in the cavity and forming an interface; and
It includes n individual electrodes (n is an integer greater than or equal to 2) and a common electrode for controlling the interface,
A first driving voltage applied between the common electrode and any one of the n individual electrodes is controlled in units of a unit cycle including a first sub-cycle and a second sub-cycle,
In the first sub-cycle, the level of the first driving voltage is a first voltage, in the second sub-cycle, the level of the first driving voltage is a second voltage;
The second voltage is a voltage obtained by summing the first voltage and a preset unit voltage. The method of claim 1,
The sum of the number of the first sub-cycle and the number of the second sub-cycle is X (X is an integer greater than or equal to 2), the liquid lens. The method of claim 1,
Within the unit cycle, in each of the first and second sub-cycles, the sum of the driving voltages between each of the n individual electrodes and the common electrode is maintained constant. 3. The method of claim 2,
In the unit cycle, if the number of the second sub-cycles among the X sub-cycles is Y, the average driving voltage in the unit cycle satisfies the following equation.
(Equation) Average driving voltage in unit cycle = first voltage + (preset unit driving voltage * Y) / X,
Here, preset unit driving voltage = second voltage - first voltage The method of claim 1,
When the first sub-cycle is changed to the second sub-cycle adjacent to the first sub-cycle, the level of the driving voltage of at least one of the n individual electrodes is changed. delete The method of claim 1,
In the unit cycle, the first driving voltage has two voltage levels. delete a liquid lens accommodated in a cavity and including a conductive liquid and a non-conductive liquid forming an interface, and n individual electrodes (n is an integer greater than or equal to 2) and a common electrode for controlling the interface; and
a control circuit for controlling a voltage applied to the n individual electrodes and the common electrode;
A first driving voltage applied between the common electrode and any one of the n individual electrodes is controlled in units of a unit cycle including a first sub-cycle and a second sub-cycle,
In the first sub-cycle, the level of the first driving voltage is a first voltage, in the second sub-cycle, the level of the first driving voltage is a second voltage;
The second voltage is a voltage obtained by summing the first voltage and a preset unit voltage. The camera module of claim 9;
a display unit for outputting an image;
a battery for supplying power to the camera module; and
An optical device comprising a housing in which the camera module, the display unit, and the battery are mounted.

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