Light-emitting element driving module and camera module

Abstract

A light emitting device driving module according to an embodiment of the present invention includes a first switching element connecting a light emitting device to a driving power source; a second switching element connecting the light emitting device to ground; a third switching element connecting the light emitting device to a storage capacitor; and a control unit controlling the operation of the first to third switching elements, wherein the light emitting device is charged by the driving power source and the storage capacitor and discharged by the ground and the storage capacitor.

Description

[Technical Field]

[0001] The present invention relates to a light-emitting element driving module and a camera module. [Background technology]

[0002] VCSEL (Vertical Cavity Surface Emitting Laser) is a type of semiconductor laser device used in the optical communications field that emits laser light perpendicular to the surface of a semiconductor wafer. In recent years, interest in VCSEL technology has been growing due to its compact size, high integration rate, low power consumption, simple manufacturing process, and heat resistance. In addition, VCSEL technology is easy to connect to photodetectors or optical fibers, and is capable of parallel signal processing due to its ease of two-dimensional arrangement. It can also be integrated with digital and analog circuits in existing semiconductor processes, and its application fields are continually expanding.

[0003] The VCSEL driver for driving such a VCSEL must stably supply a bias current signal and generate a modulation current signal at a high operating frequency to efficiently provide a stable bandwidth and high gain from the optical transmitter. Conventional laser drivers use BJT (Bipolar Junction Transistor) processes, SiGe, or BiCMOS processes. However, in order to achieve low power consumption and low manufacturing costs, there is an emerging need to develop a VCSEL driver based on pure CMOS technology, which allows for high productivity and high integration.

[0004] 2. Description of the Related Art As digital cameras, such as digital still cameras and digital video cameras, become more and more popular, consumers have an increasing desire to take high-quality photographs and videos.

[0005] In cameras for capturing moving and still images, unstable and shaky images are often captured due to shaking caused by factors external to the camera, such as camera shake or external vibrations caused by being mounted on a vehicle.

[0006] In order to prevent a decrease in the resolution of photographs due to external vibrations or shaking of the digital photographing device caused by the user's hand, an increasing number of cameras have recently been equipped with vibration correction devices. Summary of the Invention [Problem to be solved by the invention]

[0007] The technical problem to be solved by the present invention is to provide a light emitting element driving module and a camera module that can correct moving tilt after the fact.

[0008] In order to solve the above technical problem, the light-emitting element driving module of this embodiment includes a first switching element connecting the light-emitting element to a driving power supply; a second switching element connecting the light-emitting element to ground; a third switching element connecting the light-emitting element to a storage capacitor; and a control unit that controls the operation of the first to third switching elements, and the light-emitting element can be charged by the driving power supply and the storage capacitor and discharged by the ground and the storage capacitor.

[0009] The light emitting element may include an inductor disposed between the light emitting element and the third switching element.

[0010] The light emitting device may include a fourth switching element connected to the light emitting device and the storage capacitor and connected in parallel to the third switching element.

[0011] The control unit may, when operating to emit light from the light-emitting element, turn on and off the third switching element before turning on the first switching element, and may turn on and off the third switching element after turning off the first switching element.

[0012] The light emitting element may emit light when a second voltage or higher is applied thereto, and the controller may turn on the third switching element during an initial operation for the light emitting element to emit light until a first voltage is applied to the light emitting element, and the second voltage may be greater than the first voltage.

[0013] The control unit can turn off the first switching element, and turn on the third switching element after the light emitting element is turned off.

[0014] The control unit may turn on the third switching element for a first time during an initial operation for emitting light from the light-emitting element, turn on the first switching element for a second time after the first time, turn on the third switching element for a third time after the second time, and turn on the second switching element for a third time after the third time.

[0015] The light emitting device may include a plurality of light emitting devices, and the control unit may increase the first time period for turning on the third switching device as the number of the plurality of light emitting devices increases.

[0016] The light emitting device may include a parasitic capacitor, and the capacitance of the storage capacitor may be 10 times or more larger than the capacitance of the parasitic capacitor.

[0017] In order to solve the above technical problem, the light-emitting element driving module of this embodiment includes a first switching element connecting the light-emitting element to a driving power supply; a second switching element connecting the light-emitting element to ground; a third switching element connecting the light-emitting element to a storage capacitor; and a control unit that controls the operation of the first to third switching elements, and the control unit can turn on the third switching element before turning on the first switching element, thereby charging the light-emitting element with energy from the storage capacitor.

[0018] The light emitting device may include a plurality of light emitting devices, and the control unit may increase the time for turning on the third switching device as the number of the plurality of light emitting devices increases.

[0019] The control unit may turn on the third switching element after turning off the first switching element, thereby charging the energy of the light emitting element to the storage capacitor.

[0020] The control unit may turn on the second switching element after turning off the third switching element, thereby discharging energy of the light emitting element to the ground.

[0021] The light emitting element may include an inductor disposed between the light emitting element and the third switching element.

[0022] The light emitting device may include a parasitic capacitor, and the capacitance of the storage capacitor may be 10 times or more the capacitance of the parasitic capacitor.

[0023] In order to solve the above technical problem, a camera module according to an embodiment of the present invention includes an image sensor; a first driving actuator disposed on the image sensor for driving an OIS; a driving unit that applies a driving signal to the first driving actuator; and a control unit that generates a driving signal to drive the first driving actuator to correct moving tilt that occurs during at least one of zoom driving and AF driving, wherein the control unit stores sensitivity, which is a pixel movement amount on the image sensor corresponding to a driving amount of the first driving actuator, and the control unit can generate the driving signal to be applied to the first driving actuator using the pixel movement amount and the sensitivity.

[0024] The sensitivity may include a first sensitivity, which is a pixel movement amount on the image sensor according to a driving amount of the first driving actuator in a first axis direction perpendicular to the optical axis direction, and a second sensitivity, which is a pixel movement amount on the image sensor according to a driving amount of the first driving actuator in a second axis direction perpendicular to the optical axis direction, and the first axis direction and the second axis direction may be perpendicular to each other.

[0025] The camera may include a second driving actuator for zoom driving, and the control unit may store the amount of pixel movement on the image sensor caused by a moving tilt that occurs during the zoom driving.

[0026] The lens may include a third driving actuator for AF driving, and the control unit may store the amount of pixel movement on the image sensor due to a moving tilt that occurs during the AF driving.

[0027] The control unit can simultaneously store the amount of pixel movement on the image sensor due to moving tilt that occurs during the zoom drive and the AF drive.

[0028] In order to solve the above technical problem, a camera module according to another embodiment of the present invention includes an image sensor; a first driving actuator disposed on the image sensor for driving an OIS; a second driving actuator for zoom driving; a third driving actuator for AF driving; a driving unit for applying driving signals to the first to third driving actuators; and a control unit for generating a first driving signal for driving the first driving actuator to correct moving tilt that occurs during at least one of the zoom driving and the AF driving, wherein the control unit stores sensitivity, which is a pixel movement amount on the image sensor corresponding to a driving amount of the first driving actuator, and the control unit can generate the driving signal to be applied to the first driving actuator using the pixel movement amount and the sensitivity.

[0029] The control unit may store a pixel movement amount on the image sensor in response to a second driving signal applied to the second driving actuator and a pixel movement amount on the image sensor in response to a third driving signal applied to the third driving actuator.

[0030] The control unit can generate the first drive signal from the second drive signal and the third drive signal.

[0031] The sensitivity may include a first sensitivity, which is a pixel movement amount on the image sensor according to a driving amount of the first driving actuator in a first axis direction perpendicular to an optical axis direction, and a second sensitivity, which is a pixel movement amount on the image sensor according to a driving amount of the first driving actuator in a second axis direction perpendicular to the optical axis direction, and the first axis direction and the second axis direction may be perpendicular to each other.

[0032] The first sensitivity and the second sensitivity may have different slopes.

[0033] In order to solve the above technical problems, a camera module according to an embodiment of the present invention includes a housing and a bobbin disposed within the housing, and includes an actuator for driving the bobbin; a position sensor for sensing the position of the bobbin; a driver for applying a drive signal to the actuator; and a control unit for generating the drive signal based on the position sensed by the position sensor, wherein the control unit can gradually increase or decrease the level of the second drive signal when applying a second drive signal according to a second sensing period after applying a first drive signal according to a first sensing period.

[0034] The number of steps of the level of the second driving signal applied during the second sensing period may vary depending on the difference between the level of the first driving signal and the level of the second driving signal.

[0035] The control unit may increase or decrease a level step of the second driving signal applied during the second sensing period by N steps when an absolute value of a level difference between the first driving signal and the second driving signal is a first value, and may increase or decrease a level step of the second driving signal applied during the second sensing period by M steps when an absolute value of a level difference between the first driving signal and the second driving signal is a second value, and N may be greater than M when the first value is greater than the second value.

[0036] The control unit may increase or decrease the drive signal in steps having a level difference of X when an absolute value of a level difference between the first drive signal and the second drive signal is a first value, and may increase or decrease the drive signal in steps having a level difference of Y when an absolute value of a level difference between the first drive signal and the second drive signal is a second value, and X may be greater than Y when the first value is greater than the second value.

[0037] In order to solve the above technical problems, a camera module according to an embodiment of the present invention includes a housing; a bobbin disposed within the housing; a ball disposed between the bobbin and the housing; a magnet disposed on the bobbin; a coil disposed facing the magnet; a position sensor disposed facing the magnet; a driver that applies a drive signal to the coil; and a control unit that generates the drive signal based on a position sensed by the position sensor, wherein the control unit can gradually increase or decrease the level of the second drive signal when applying a second drive signal according to a second sensing period after applying a first drive signal according to a first sensing period.

[0038] The second sensing period may be consecutive in time to the first sensing period.

[0039] The first sensing period and the second sensing period may have the same time interval.

[0040] During the first sensing period, the first drive signal applied to the coil may not be changed, and during the second sensing period, the drive signal applied to the coil may be changed at least twice. [Effects of the Invention]

[0041] According to this embodiment, the remaining energy used for emitting light in the light emitting element is stored in a capacitor without being discharged, and when emitting light again, the energy stored in the capacitor is used as a bias voltage, thereby reducing energy consumption and providing an advantage in terms of efficient energy management.

[0042] In addition, since the amount of energy charged in the capacitor can be adjusted using LC resonance, high-speed light emission can be achieved even when the number of light emitting elements is increased.

[0043] In addition, even if the number of light emitting elements is changed and the magnitude of the bias voltage required for light emission changes, the necessary bias voltage for the light emitting elements can be applied through switching time control, so there is no need to change the design of the light emitting element driving module every time the number of light emitting elements is changed.

[0044] According to this embodiment, it is possible to improve the moving tilt that occurs due to a long stroke during zoom driving or AF driving.

[0045] Furthermore, by calibrating the zoom drive actuator, AF drive actuator, and OIS drive actuator, which have different dimensional systems, in advance based on the image sensor, it is possible to improve moving tilt more instantly.

[0046] According to this embodiment, it is possible to reduce noise generated when the ball type actuator is driven through fine control.

[0047] Furthermore, by dynamically changing the number of steps and the magnitude of the signal at each step in accordance with the magnitude of the drive signal applied to the actuator, it is possible to optimize the drive control of the actuator. [Brief explanation of the drawings]

[0048] [Figure 1] FIG. 2 is a circuit diagram of a light-emitting element driving module. [Figure 2] 10A and 10B are diagrams for explaining the operation of the light-emitting element driving module. [Figure 3] FIG. 2 is a block diagram of a light-emitting element driving module according to the present embodiment. [Figure 4] and [Figure 5] FIG. 2 is a circuit diagram of a light-emitting element driving module according to the present embodiment. [Figure 6] 5A to 5C are diagrams for explaining the operation of the light-emitting element driving module according to the present embodiment. [Figure 7] FIG. 10 is a circuit diagram of a light emitting device driving module according to another embodiment of the present invention. [Figure 8] 10A and 10B are diagrams illustrating an operation in which a resonance phenomenon occurs when energy is charged from a storage capacitor to a light emitting device according to an embodiment of the present invention; [Figure 9] FIG. 10 is a circuit diagram of a light emitting device driving module according to another embodiment of the present invention. [Figure 10] FIG. 10 is a circuit diagram of a light emitting device driving module according to another embodiment of the present invention. [Figure 11] FIG. 1 is a block diagram of a camera module according to an embodiment of the present invention. [Figure 12] 1 is a block diagram of a camera module according to another embodiment of the present invention. [Figure 13] 10 is a graph showing sensitivity stored in a control unit of a camera module according to an embodiment of the present invention. [Figure 14] 10A and 10B are diagrams for explaining a moving tilt correction operation of the camera module according to the embodiment. [Figure 15] FIG. 2 is an exploded perspective view of the lens driving device according to the embodiment of the present invention. [Figure 16] FIG. 10 is an exploded perspective view of a lens driving device according to another embodiment of the present invention. [Figure 17] FIG. 10 is an exploded perspective view of a lens driving device according to another embodiment of the present invention. [Figure 18] FIG. 10 is a diagram for explaining closed-loop control of a camera module. [Figure 19] FIG. 10 is a diagram for explaining closed-loop control of a camera module. [Figure 20] FIG. 2 is a block diagram of a camera module according to an embodiment of the present invention. [Figure 21] 5A to 5C are diagrams illustrating a control operation of a camera module according to an embodiment of the present invention. [Figure 22] 5A to 5C are diagrams illustrating a control operation of a camera module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0049] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0050] However, the technical concept of the present invention is not limited to the described embodiments, but can be implemented in various different forms, and one or more of the components of the embodiments can be selectively combined or substituted for each other within the scope of the technical concept of the present invention.

[0051] Furthermore, unless otherwise clearly defined and described, the terms used in this embodiment (including technical and scientific terms) may be interpreted in the sense that they are commonly understood by a person of ordinary skill in the art to which this embodiment belongs, and commonly used terms, such as dictionary-defined terms, may be interpreted in the sense that they are commonly understood by a person of ordinary skill in the art, taking into account the contextual meaning of the relevant art.

[0052] Furthermore, the terms used in the present embodiment are intended to explain the examples and do not limit the present invention.

[0053] In this specification, unless otherwise specified, the singular form can also include the plural form, and when it is stated as "A and (and) at least one (or more) of B and C," it can include one or more of all combinations of A, B, and C.

[0054] Furthermore, in describing the components of this embodiment, terms such as first, second, A, B, (a), (b), etc. are used to distinguish the components from other components, and the terms do not limit the essence, order, or sequence of the components.

[0055] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it includes not only cases where the component is directly "coupled," "coupled," or "connected" to the other component, but also cases where the component is "coupled," "coupled," or "connected" by another component between the component and the other component.

[0056] Furthermore, when described as being formed or disposed "above" or "below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components. Furthermore, when expressed as "above" or "below," it can include not only the upward direction but also the downward direction based on one component.

[0057] The "optical axis direction" used below is defined as the optical axis direction of the lens and / or image sensor coupled to the lens driving device.

[0058] The "vertical direction" used below may be parallel to or the same as the optical axis direction. The vertical direction may correspond to the "z-axis direction." The "horizontal direction" used below may be a direction perpendicular to the vertical direction. That is, the horizontal direction may be a direction perpendicular to the optical axis. Therefore, the horizontal direction may include the "x-axis direction" and the "y-axis direction."

[0059] The "autofocus (AF) function" used below is defined as a function that automatically focuses on a subject by adjusting the distance from the image sensor by moving the lens along the optical axis according to the distance of the subject so that a clear image of the subject can be obtained on the image sensor. Also, the "autofocus feedback (CLAF) control" is defined as detecting the distance between the image sensor and the lens and controlling the lens position in real time using feedback to improve the accuracy of focus adjustment.

[0060] The term "optical image stabilization (OIS) function" used below is defined as a function that moves or tilts the lens in a direction perpendicular to the optical axis to offset camera shake, preventing the phenomenon of shaking in images or videos caused by the user's camera shake. Additionally, the term "image stabilization feedback control" defines the function of detecting the position of the lens relative to the image sensor and providing feedback to control the lens position in real time to improve the accuracy of image stabilization.

[0061] FIG. 1 is a circuit diagram of the light-emitting element driving module, and FIG. 2 is a diagram for explaining the operation of the light-emitting element driving module.

[0062] A VCSEL (Vertical Cavity Surface Emitting Laser), a type of light-emitting device, is a type of semiconductor laser device that emits laser light in a direction perpendicular to the surface of a semiconductor wafer in the field of optical communications. The light-emitting device can be an LED (Light Emitting Diode).

[0063] The circuit for driving the light emitting device may include a first switching element S1 that controls the application of driving power and a second switching element S2 that controls the ground connection. Referring to Figure 2, the light emitting device may emit light when a voltage equal to or greater than Vf is applied, and may be turned off when a voltage equal to or less than Vf is applied. This may be considered as including a switch Sd that is turned on when the voltage applied to the light emitting device is equal to or greater than Vf, and turned off when the voltage is equal to or less than Vf.

[0064] During initial driving of the light emitting device to emit light, the first switching element S1 is turned on to increase the voltage applied to the light emitting device. At this time, a rising time (Tr) is required from the time the first switching element S1 is turned on until the light emitting device emits light. If the rising time increases, the period during which the light emitting device cannot emit light even when the driving power is applied increases, resulting in unnecessary consumption of energy X.

[0065] Thereafter, the first switching element S1 turns off, and when the voltage applied to the light emitting element falls below Vf, the light emitting element goes out. After the dead time from when the first switching element S1 turns off, the second switching element S2 turns on to discharge the energy Y remaining in the light emitting element to ground. In other words, the energy Y remaining in the light emitting element is wasted without being used to emit light, which creates a problem in terms of efficient energy management.

[0066] Figure 3 is a block diagram of a light-emitting element driving module according to this embodiment, Figures 4 and 5 are circuit diagrams of the light-emitting element driving module according to this embodiment, Figure 6 is a diagram for explaining the operation of the light-emitting element driving module according to this embodiment, Figure 7 is a circuit diagram of a light-emitting element driving module according to another embodiment of the present invention, Figure 8 is a diagram for explaining the operation of the resonance phenomenon occurring when energy is charged to the light-emitting element in the storage capacitor according to this embodiment, and Figures 9 and 10 are circuit diagrams of light-emitting element driving modules according to other embodiments of the present invention.

[0067] The light emitting device driving module 100 according to this embodiment may include a circuit unit 110 connected to the light emitting device 1 and a control unit 120 that controls the circuit unit 110. The control unit 120 may control the circuit unit 110 to control the emission and extinction of the light emitting device (D). The light emitting device driving module 100 may be referred to as a light emitting device driving driver or a light emitting device driving IC.

[0068] One end of the light emitting element (D) may be connected to the circuit unit 110, and the other end may be connected to ground. For example, the light emitting element (D) may be a VCSEL (Vertical Cavity Surface Emitting Laser) or an LED (Light Emitting Diode).

[0069] The light emitting device (D) may include a parasitic capacitor (Cd) and an internal resistor (Rd) therein. Referring to FIG. 5, the light emitting device (D) is illustrated as having the parasitic capacitor (Cd) and the internal resistor (Rd) connected in parallel and the parasitic switch (Sd) connected in series, but this is for convenience of explanation, and in reality, the parasitic capacitor (Cd) and the internal resistor (Rd) may be included within the light emitting device (D).

[0070] The circuit unit 110 may include a first switching element S1 connecting the light emitting element D to a driving power supply VDD, a second switching element S2 connecting the light emitting element D to ground, and a third switching element S3 connecting the light emitting element D to a storage capacitor Cs. The first to third switching elements S1, S2, and S3 may be any of a switch, a relay, and a MOSFET.

[0071] Resistors may be connected to the first to third switching elements (S1, S2, S3), respectively. The resistors connected to the switching elements may be connected to prevent short circuits. The resistors connected to the switching elements may have a large resistance value to prevent overcurrent, for example, a value of 1 kΩ to 10 kΩ.

[0072] The control unit 120 can control the operations of the first to third switching elements (S1, S2, S3). The control unit 120 can control the first to third switching elements (S1, S2, S3) to perform on or off operations. Here, the on operation refers to a short state in which the switch is connected and current flows through the circuit, and the off operation refers to an open state in which the switch is not connected and current does not flow through the circuit.

[0073] 6, the light emitting element D emits light when a voltage equal to or greater than the second voltage V2 is applied, and turns off when a voltage equal to or less than the second voltage V2 is applied. This means that the light emitting element includes a parasitic switch Sd that is turned on when the applied voltage is equal to or greater than the second voltage V2 and turned off when the applied voltage is equal to or less than the second voltage V2. In other words, the parasitic switch Sd can be automatically turned on when the potential of the light emitting element D is equal to or greater than the second voltage V2, and automatically turned off when the potential of the light emitting element D is equal to or less than the second voltage V2.

[0074] Referring to FIG. 6, the light emitting and extinction operations of the light emitting device D can be implemented in an operation mode consisting of sections A to H.

[0075] In section A, the third switching element S3 is turned on, and energy X stored in the storage capacitor Cs can be charged to the light-emitting element D. The on-state of the third switching element S3 allows energy X stored in the storage capacitor Cs to be charged to the parasitic capacitor Cd of the light-emitting element D. The third switching element S3 can be turned on until the potential of the light-emitting element D reaches the first voltage V1. The actual energy stored in the storage capacitor Cs may be greater than the energy X charged to the light-emitting element D by the on-state of the third switching element S3. The longer the time the third switching element S3 is turned on, the more energy X is charged from the storage capacitor Cs to the light-emitting element D. The first voltage V1 applied to the light-emitting element D can function as a bias voltage.

[0076] The capacitance of the storage capacitor (Cs) may be 10 times or more the capacitance of the parasitic capacitor (Cd) of the light-emitting element (D). If the energy charged in the storage capacitor (Cs) is greater than the energy charged in the parasitic capacitor (Cd), the energy charged in the storage capacitor (Cs) may be transferred to the parasitic capacitor (Cd). Conversely, if the energy charged in the parasitic capacitor (Cd) is greater than the energy charged in the storage capacitor (Cs), the energy charged in the parasitic capacitor (Cd) may be transferred to the storage capacitor (Cs). In section G described below, when the energy remaining in the parasitic capacitor (Cd) is charged to the storage capacitor (Cs) after the light-emitting element (D) emits light, the capacitance of the storage capacitor (Cs) is sufficiently greater than the capacitance of the parasitic capacitor (Cd) of the light-emitting element (D), so from the perspective of the parasitic capacitor (Cd), energy may be charged to the storage capacitor (Cs) as if it were connected to ground.

[0077] Section B may be a section in which the third switching element S3 is turned off and before the first switching element S1 is turned on. After section B, in section C, the first switching element S1 is turned on and the driving power supply VDD is applied. The voltage applied to the light emitting element D may increase from the first voltage V1 to the third voltage V3 depending on the time the first switching element S1 is turned on. The voltage applied to the light emitting element D may increase linearly depending on the time the first switching element S1 is turned on. In section C, as the voltage applied to the light emitting element D increases from the first voltage V1 to the third voltage V3, if it reaches the second voltage V2 at which the parasitic switch Sd is turned on, some of the energy is used to turn on the parasitic switch Sd, so a temporary section in which the voltage does not increase may occur.

[0078] The rise time Tr, which is the time from when the driving power supply VDD is applied to the light emitting element D until the light emitting element D emits light, may be the time it takes for the voltage to rise from the first voltage V1 to the second voltage V2. Conventionally, the rise time Tr refers to the time it takes for the voltage applied to the light emitting element D to rise from 0V to the second voltage V2. However, according to this embodiment, the energy already stored in the storage capacitor Cs is charged to the light emitting element D in section A, thereby raising the voltage to the first voltage V1, so the rise time Tr can be shortened. This allows the light emitting element D to emit light at a high speed based on the time when the driving power supply VDD is applied to the light emitting element D, thereby reducing energy consumption. In other words, the light emitting element D can emit light at a high speed based on the time when the first switching element S1 is turned on.

[0079] In section D, when the voltage applied to the light emitting element D is equal to or greater than the second voltage V2, the parasitic switch Sd is turned on, causing the light emitting element D to emit light. The luminance of the light emitting element D may gradually increase as the applied voltage increases and may gradually decrease as the applied voltage decreases. The rated voltage that can be applied to the light emitting element D may be a third voltage V3. The light emitting element D may emit light at maximum luminance at the third voltage V3.

[0080] In section E, the first switching element S1 is turned off, and the voltage applied to the light-emitting element D may decrease. In this section, the voltage applied to the light-emitting element D gradually decreases from the third voltage V3, which is the maximum voltage, but remains greater than the second voltage V2, so the parasitic switch Sd may maintain its on state. That is, in section E, even though the first switching element S1 is turned off, the parasitic switch Sd may maintain its on state, and the light-emitting element D may emit light at a brightness lower than the maximum brightness, but may gradually extinguish.

[0081] In section F, as the voltage applied to the light-emitting element D becomes lower than the second voltage V2, the parasitic switch Sd turns off. Because some energy is also used in the off operation of the parasitic switch Sd, there may be a temporary period during which the voltage applied to the light-emitting element D does not decrease. Sections E and F are sections where the on / off operations of the first switching element S1 and the third switching element S3 intersect, and therefore may be dead time sections where both switches are turned off to prevent both switches from turning on at the same time. Section F is a section where the on / off operations of the parasitic switch Sd and the third switching element S3 intersect, and therefore may be a dead time section where both switches are turned off to prevent both switches from turning on at the same time.

[0082] In section G, the third switching element S3 is turned on to connect the light emitting element D to the storage capacitor Cs. When the third switching element S3 is turned on, the remaining energy Y from the light emitting element D can be charged to the storage capacitor Cs. When the third switching element S3 is turned on, the remaining energy Y in the parasitic capacitor Cd after the light emitting element D emits light can be charged to the storage capacitor Cs. The energy Y charged from the parasitic capacitor Cd to the storage capacitor Cs can be used to charge the parasitic capacitor Cd in section A, where light is emitted later.

[0083] In section H, the second switching element S2 is turned on, connecting the light emitting element D to ground. Although not shown, a dead time period may be included between section G and section H because this is a period where the on / off operations of the second switching element S2 and the third switching element S3 intersect. In this dead time period, an inrush current may occur due to the on operation of the second switching element S2.

[0084] Looking at the overall operation of sections A to H, which are the light-emitting and light-extinguishing operations of light-emitting element D, the third switching element S3 is turned on and off before the first switching element S1 for connecting light-emitting element D to the driving power supply VDD is turned on, thereby charging the energy stored in the storage capacitor Cs to the light-emitting element D. This allows the first voltage V1, which is a bias voltage, to be applied to the light-emitting element D. The first voltage V1 may be lower than the second voltage V2 required for light-emitting element D to emit light. Then, after the first switching element S1 is turned on, the third switching element S3 is turned on and off, thereby charging the energy remaining in the light-emitting element D after light emission to the storage capacitor Cs.

[0085] During the initial operation for emitting light from the light emitting element D, the control unit 120 may turn on the third switching element S3 for a first time period, turn on the first switching element S1 for a second time period after the first time period, turn on the third switching element S3 for a third time period after the second time period, and turn on the second switching element S2 for a third time period after the third time period. Here, the first time period may refer to the time period for applying a first voltage V1, which is lower than the second voltage V2, to the light emitting element D. The second time period may refer to the time period for emitting light from the light emitting element D. The third time period may refer to the time period for charging the storage capacitor Cs with the energy remaining in the light emitting element D after emitting light.

[0086] Referring to Fig. 7, the circuit unit 110 may further include an inductor L disposed between the light emitting element D and the third switching element S3. Thus, when the energy stored in the storage capacitor Cs is charged in the light emitting element D, the energy can be amplified and charged through the resonance phenomenon between the inductor L and the storage capacitor Cs. Referring to Fig. 8, when resonance occurs, the peak time at which the voltage is amplified to the maximum voltage is TIFF2026502146000002.tif16155, so that the ON time of the third switching element (S3) can be adjusted taking this into consideration.

[0087] 9, the circuit unit 110 may further include a fourth switching element S4 that connects the light emitting element D and the storage capacitor Cs and is connected in parallel with the third switching element S3. The control unit 120 may turn on the third switching element S3 when connecting the storage capacitor Cs to the inductor L to charge the light emitting element D, and may turn on the fourth switching element S4 when not connecting the inductor L to charge the light emitting element D.

[0088] 10, the light emitting element (D) may include a plurality of light emitting elements (D1, D2, D3, D4). The number of light emitting elements (D) may be increased or decreased depending on the desired brightness and connected to the light emitting element driving module 100. As the number of light emitting elements (D) increases, the power supply required to drive the light emitting elements (D) may become larger. Therefore, as the number of light emitting elements (D) increases, the power supply must be increased in size.

[0089] The light emitting device driving module 100 according to this embodiment can adjust the on-operation time of the third switching device (S3) to make the light emitting device (D) emit light without changing the existing design or the size of the driving power supply (VDD), even if the number of light emitting devices (D) is changed. As the number of light emitting devices (D) increases, the magnitude of the third voltage (V3), which is the voltage required to drive the light emitting devices (D), can increase. Therefore, the magnitude of the first voltage (V1) needs to be increased in accordance with the increasing third voltage (V3). Since the first voltage (V1) is generated by charging the light emitting devices (D) using the energy stored in the storage capacitor (Cs), the control unit 120 can increase the magnitude of the first voltage (V1) by increasing the time that the storage capacitor (Cs) is connected to the light emitting devices (D). The control unit 120 can increase the time for which the third switching device (S3) is turned on as the number of light emitting devices increases. In addition, in the case of the light emitting element driving module 100 in which the inductor L is connected between the third switching element S3 and the light emitting element D, the control unit 120 can boost the voltage of the inductor L to charge the light emitting element D. Specifically, when resonance occurs through the inductor L and the storage capacitor Cs, the peak time at which the voltage is amplified to the maximum voltage is TIFF2026502146000003.tif15157, and the ON time of the third switching element (S3) can be adjusted taking this into consideration.

[0090] According to this embodiment, the remaining energy used by the light emitting device to emit light is stored in a capacitor without being discharged, and when the light is emitted again, the energy stored in the capacitor is used as a bias voltage, thereby reducing energy consumption and providing an advantage in terms of efficient energy management. Furthermore, since the amount of energy charged in the capacitor can be adjusted using LC resonance, high-speed light emission can be achieved even when the number of light emitting devices is increased. Furthermore, even if the amount of bias voltage required for light emission changes due to a change in the number of light emitting devices, the necessary bias voltage can be applied to the light emitting devices by controlling the switching time. Therefore, there is no need to change the design of the light emitting device driving module every time the number of light emitting devices is changed.

[0091] As described above, the light emitting element driving module according to the embodiment of the present invention has been described with reference to Figures 1 to 10. Hereinafter, the camera module according to the embodiment of the present invention will be described with reference to Figures 11 to 14. The detailed description of the camera module according to the embodiment of the present invention may be the same as or different from the light emitting element driving module according to the embodiment of the present invention in terms of names, terms, or functions based on the detailed description of each embodiment.

[0092] FIG. 11 is a block diagram of a camera module according to this embodiment, FIG. 12 is a block diagram of a camera module according to another embodiment of the present invention, FIG. 13 is a sensitivity graph stored in a control unit of the camera module according to this embodiment, and FIG. 14 is a diagram for explaining the moving tilt correction operation of the camera module according to this embodiment.

[0093] Deviations in the autofocus characteristics occur in each mass-produced camera module due to lens deviations during mass production of camera modules, deviations in the dynamic characteristics of the actuator, deviations in the electrical characteristics of the actuator, and deviations in the assembly of the actuator within the camera module. In the case of AF drive and zoom drive actuators, when they operate with a long stroke, a moving tilt phenomenon occurs in which the target moves. To correct this, it is necessary to drive the OIS drive actuator, which drives in a direction perpendicular to the optical axis.

[0094] However, since AF drive and zoom drive mean driving the lens or image sensor in the direction of the optical axis, and OIS drive means driving it in a direction perpendicular to the optical axis, there is a problem in that even if moving tilt occurs due to AF drive and zoom drive, it is unclear to what extent it should be corrected by OIS drive.

[0095] The present invention solves this problem by calibrating the pixel movement amount of the image sensor in advance according to the drive amount of the OIS drive actuator, and when moving tilt occurs, the OIS drive signal can be generated based on the pixel movement amount of the target movement on the image sensor. That is, since the AF drive / zoom drive actuator and the OIS drive actuator have different dimensions, moving tilt can be corrected by pre-calibrating both drive systems based on the pixel movement amount of the image sensor.

[0096] The camera module according to this embodiment may include an image sensor, a first driving actuator 11, a driving unit 12, and a control unit 13. A camera module according to another embodiment of the present invention may include an image sensor, a first driving actuator 11, a second driving actuator 14, a third driving actuator 15, a driving unit 12, and a control unit 13.

[0097] The first drive actuator 11 is an actuator for driving the OIS. The first drive actuator 11 can be disposed on the image sensor. Driving the OIS can mean driving the lens or the image sensor in a direction perpendicular to the optical axis. The OIS drive actuator can also be called an image stabilization actuator.

[0098] The second drive actuator 14 is an actuator for zoom drive. The zoom drive can mean continuous zoom drive. The zoom drive can mean moving at least one of a plurality of lens groups included in the optical system in the optical axis direction.

[0099] The third drive actuator 15 is an actuator for AF drive. The AF drive may mean fixed zoom drive. The AF drive may mean driving a lens or an image sensor in the optical axis direction for focus adjustment.

[0100] When the first drive actuator 11 to the third drive actuator 15 drive a lens, they can be called a lens drive device. When the first drive actuator 11 to the third drive actuator 15 drive an image sensor, they can be called a sensor drive device.

[0101] The driving unit 12 can apply a driving signal to the first driving actuator 11. The driving unit 12 can apply driving signals to the first driving actuator 11 to the third driving actuator 15. The driving unit 12 can apply a first driving signal to the first driving actuator 11. The driving unit 12 can apply a second driving signal to the second driving actuator 14. The driving unit 12 can apply a third driving signal to the third driving actuator 15. The driving unit 12 may be in the form of a driver IC.

[0102] The control unit 13 may generate a drive signal to be applied to the first drive actuator 11 to correct a moving tilt that occurs during at least one of zoom drive and AF drive. The control unit 13 may generate a drive signal to be applied to the first drive actuator 11 based on the amount of pixel movement on the image sensor caused by the moving tilt.

[0103] The control unit 13 may store sensitivity, which is the amount of pixel movement on the image sensor depending on the amount of drive of the first drive actuator 11. The control unit 13 may generate a drive signal to be applied to the first drive actuator 11 using the amount of pixel movement and the sensitivity. The sensitivity may be a relationship between the amount of drive of the first drive actuator 11 and the amount of pixel movement on the image sensor. The sensitivity may be expressed in the form of a look-up table (LUT) between the amount of drive of the first drive actuator 11 and the amount of pixel movement on the image sensor. The control unit 13 may store the amount of drive of the first drive actuator 11 depending on the amount of pixel movement on the image sensor. The amount of drive of the first drive actuator 11 may refer to the magnitude of the drive current applied to the first drive actuator 11. The amount of drive of the first drive actuator 11 may refer to the magnitude of the drive code applied to the first drive actuator 11. The amount of drive of the first drive actuator 11 may refer to the magnitude of the signal applied to the first drive actuator 11 to move the lens or the image sensor in the x-axis or y-axis direction perpendicular to the optical axis (z-axis).

[0104] When a moving tilt occurs, it is not possible to determine how much the first driving actuator 11 should be moved to move it to the original target on the image sensor, so the sensitivity is calibrated in advance. After that, when a moving tilt causes a target movement on the image sensor, the driving amount of the first driving actuator 11 can be calculated from the pixel movement amount on the image sensor.

[0105] The sensitivity may include a first sensitivity, which is a pixel movement amount on the image sensor due to a driving amount in a first axis direction perpendicular to the optical axis direction of the first driving actuator 11. The sensitivity may include a second sensitivity, which is a pixel movement amount on the image sensor due to a driving amount in a second axis direction perpendicular to the optical axis direction of the first driving actuator 11. Here, the first axis direction and the second axis direction may be perpendicular to each other. The first axis direction may refer to the x-axis direction, and the second axis direction may refer to the y-axis direction.

[0106] Referring to FIG. 13, the first sensitivity may have a first slope on a graph with the x-axis representing the "x-axis driving amount" and the y-axis representing the "x-axis pixel." The second sensitivity may have a second slope on a graph with the x-axis representing the "y-axis driving amount" and the y-axis representing the "y-axis pixel." The first slope and the second slope may have the same value. The first slope and the second slope may have different values. The first sensitivity and the second sensitivity may be calibrated and stored in advance. Although FIG. 13 illustrates a linear relationship between the "driving amount of the first driving actuator 11" and the "pixel amount on the image sensor," this is not limiting and may vary depending on the characteristics of the actuators arranged in the camera module.

[0107] Referring to Figure 14(a), target 1 can be located in the center area of ​​the image sensor before AF drive or zoom drive operation. Referring to Figure 14(b), when AF drive or zoom drive is performed, moving tilt occurs, and target 1 moves by Δx in the x-axis direction and Δy in the y-axis direction based on target 2, which is the center of the image sensor.

[0108] Therefore, the moving tilted target 1 must be corrected to the position of target 2 through the first driving actuator 11 that drives the OIS. The control unit 13 calculates (Δx, Δy), which is the pixel movement amount on the image sensor due to the target movement, and can calculate the x-axis driving amount and y-axis driving amount of the first driving actuator 11 based on (Δx, Δy) and the first sensitivity and second sensitivity that have been calibrated in advance.

[0109] The control unit 13 can store the amount of pixel movement on the image sensor due to the moving tilt that occurs during zoom driving. The control unit 13 can store the amount of pixel movement on the image sensor due to the moving tilt that occurs during AF driving. The control unit 13 can simultaneously store the amount of pixel movement on the image sensor due to the moving tilt that occurs during zoom driving and AF driving.

[0110] The control unit 13 can store the amount of pixel movement on the image sensor caused by the second driving signal applied to the second driving actuator 14. The control unit 13 can store the amount of pixel movement on the image sensor caused by the third driving signal applied to the third driving actuator 15. The control unit 13 can also store the amount of pixel movement on the image sensor caused when the second driving signal is applied to the second driving actuator 14 and the third driving signal is applied to the third driving actuator 15.

[0111] During the stroke operations of the second drive actuator 14 for zoom drive and the third drive actuator 15 for AF drive, the moving tilt that occurs due to deviations in the dynamic characteristics of the actuators, deviations in the electrical characteristics of the actuators, deviations in the assembly of the actuators within the camera module, etc. may be constant. For example, when the second drive actuator 14 strokes by a length A, a moving tilt in which the target moves by a length B may always occur. Alternatively, when the third drive actuator 15 strokes by a length C, a moving tilt in which the target moves by a length D may always occur.

[0112] Therefore, if the pixel movement amount on the image sensor due to the moving tilt that occurs during zoom drive and the pixel movement amount on the image sensor due to the moving tilt that occurs during AF drive are calibrated in advance, the drive amount of the first drive actuator 11 can be calculated more quickly without having to directly check the pixel movement amount on the image sensor.

[0113] The control unit 13 can generate the first drive signal from the second drive signal and the third drive signal. The control unit 13 is pre-calibrated with respect to the relationship between the applied second drive signal and third drive signal and the pixel movement amount on the image sensor and the pixel movement amount on the image sensor and the drive amount of the first drive signal. After that, the control unit 13 checks at least one of the second drive signal and the third drive signal and can immediately generate the first drive signal.

[0114] As described above, the camera module according to the embodiment of the present invention has been described with reference to Figures 11 to 14. Hereinafter, the camera module according to the embodiment of the present invention and the control operation of the camera module will be described with reference to Figures 15 to 22. In the detailed description of the camera module according to the embodiment of the present invention, the names, terms, and functions of the camera module according to the embodiment of the present invention and the control operation of the camera module may be the same or different from each other based on the detailed description of each embodiment.

[0115] The lens driving device 1000A shown in Fig. 15 may be a ball-type lens driving device, which may be referred to as a lens driving actuator.

[0116] 15, lens driving device 1000A can include a housing 1400, a bobbin 1230 disposed within housing 1400 and for coupling with a lens module, a coil 1320 disposed in housing 1400, a magnet 1310 disposed on bobbin 1230, a ball 1600 disposed between housing 1400 and bobbin 1230, and a yoke 1340 disposed on housing 1400. Ball 1600 can also be expressed interchangeably as a "ball member" or a "ball bearing."

[0117] The lens driving device 1000A may include a cover member 1100 that is coupled to the housing 1400 so as to enclose the outer surface of the housing 1400. The lens driving device 1000A may include a position sensor 1350 that is disposed in the housing 1400. The lens driving device 1000A may also include a circuit board 1330 that is disposed in the housing 1400, and the position sensor 1350 may be mounted on the circuit board 1330 and may be electrically connected to the circuit board 1330.

[0118] The bobbin 1230 may have an opening for coupling with the lens module, and the opening of the bobbin 1230 may be a through-hole that penetrates the bobbin in the optical axis direction. The magnet 1310 may be disposed on the outer surface of the bobbin 1230. A groove in which the magnet 1310 is disposed may be formed on the outer surface of the bobbin 1230.

[0119] The coil 1320 can be disposed on either side 1420 of the housing 1400, facing the magnet 1310. For example, a groove can be formed on either side of the housing 1400 for the magnet 1310 to be disposed therein. In other embodiments, the magnet can be disposed on the housing, and the coil can be disposed on a bobbin.

[0120] The housing 1400 may have an opening 1401 corresponding to the lens module 400, and the opening 1401 of the housing 140 may be in the form of a through-hole that penetrates the housing 1400 in the optical axis direction.

[0121] The coil 1320 may be electrically connected to a circuit board 1330 .

[0122] The ball 1600 can support relative movement of the bobbin 1230 with respect to the housing 1400. At least a portion of the ball 1600 can contact at least a portion of the housing 1400 and at least a portion of the bobbin 1230, thereby reducing friction between the housing 1400 and the bobbin 1230.

[0123] The yoke 1340 may be disposed on one side of the housing 1400 and may face the magnet 1310 in a direction perpendicular to the optical axis. For example, the yoke 1340 may be disposed outside the circuit board 1330, and the coil 1320 may be disposed between the yoke 1340 and the magnet 1310.

[0124] The yoke 1340 may be made of a material, such as a magnet or metal, that can generate an attractive force between it and the magnet 1310, thereby allowing an attractive force to act between the yoke 1340 and the magnet 1310 in a direction perpendicular to the optical axis direction. This attractive force allows the ball 1600 to maintain contact with the bobbin 1230 and the housing 1400.

[0125] The housing 1400 may be formed with a first receiving groove 1410 for receiving at least a portion of the ball 1600 or for disposing at least a portion of the ball 1600. The bobbin 1230 may be formed with a second receiving groove 1231 for receiving at least another portion of the ball 1600 or for disposing at least another portion of the ball 1600.

[0126] The first accommodating groove 1410 may be formed on the inner or inner surface of at least one corner of the housing 1400, and the second accommodating groove 1231 may be formed on the outer or outer surface of at least one corner of the bobbin 1230. The first accommodating groove 1410 and the second accommodating groove 1231 may face each other or oppose each other, and the ball 1600 may be disposed between the first accommodating groove 1410 and the second accommodating groove 1231 and may contact each of the first accommodating groove 1410 and the second accommodating groove 1231. The number of balls 1600 disposed between the first accommodating groove 1410 and the second accommodating groove 1231 may be one or more.

[0127] In FIG. 15, a first accommodating groove can be formed in each of two corners of the housing 1400 that face each other or are located on opposite sides, and a second accommodating groove can be formed in each of two corners of the bobbin 1230 that correspond to the two corners of the housing 140.

[0128] In other embodiments, a first receiving groove can be formed at each of the four corners of the housing 1400, and a second receiving groove can be formed at each of the four corners of the bobbin 1230 corresponding to the four corners of the housing 1400.

[0129] In another embodiment, a first receiving groove may be formed in each of two corners of the housing 1400 adjacent to the side 1420 of the housing 1400 where the coil 1320 and / or the circuit board 1330 are disposed.

[0130] Also, second receiving grooves may be formed at two corners of the bobbin 1230 corresponding to the two corners of the side portion 1420 of the housing 1400 and the two adjacent housings 1400, respectively.

[0131] In another embodiment, a first receiving groove may be formed at each of two corners adjacent to a side portion located opposite the side portion 1420 of the housing 1400. A second receiving groove may be formed at each of two corners of the bobbin 1230 corresponding to the two corners adjacent to the side portion located opposite the side portion 1420 of the housing 1400.

[0132] 15, the housing 1400 may be realized as a single body, but is not limited to this. In another embodiment, the housing 1400 may include a housing and a base coupled to the housing. In this case, the base may have an opening that is the same as or similar to the opening 1401 of the housing 1400.

[0133] FIG. 16 may be a lens driving device 1000B which is a modified embodiment of FIG.

[0134] In FIG. 16, the balls 1600 can be positioned between the two corners adjacent to the side 1420 of the housing 1400 where the coil 1320 and / or circuit board 1330 are located and the corresponding outer surface of the bobbin 1230.

[0135] For example, in FIG. 16 , the first accommodating groove 1410 can be formed in each of the two corners of the housing 1400 adjacent to the side 1420 of the housing 1400 on which the coil 1320 and / or circuit board 1330 are disposed, and the second accommodating groove 1231 can be formed in the corners of the bobbin 1230 corresponding to the two corners of the housing 1400.

[0136] The magnet 1310A can be disposed between the balls 1600 accommodated in the second accommodation grooves 1231 formed in the two corners of the bobbin 1230. For example, the magnet 1310A can be disposed between the two second accommodation grooves 1231 formed in the two corners of the bobbin 1230.

[0137] FIG. 17 may be a lens driving device 100C which is a modified embodiment of FIG.

[0138] 15 and 16 is a lens driving device that drives bobbin 1230 or a lens module placed inside bobbin 1230 in the optical axis direction. The lens driving device shown in Fig. 17 is a lens driving device that drives bobbin 1230 or a lens module placed inside bobbin 1230 in the optical axis direction and in a direction perpendicular to the optical axis.

[0139] 17, the bobbin 1230 may be disposed within a first housing 1450, which may be disposed within a second housing 1460. A ball 1600 for AF drive may be disposed between the first housing 1450 and the second housing 1460. The ball 1600 may support relative movement of the first housing 1450 with respect to the second housing 1460. A coil 1320 may be disposed on the outside of the second housing 1460.

[0140] A moving member 1510 may be disposed between a lower surface of the bobbin 1230 and the first housing 1450. A first ball 1710 may be disposed between a lower surface of the bobbin 1230 and an upper surface of the moving member 1510, and a second ball 1720 may be disposed between a lower surface of the moving member 1510 and the first housing 1450. The first ball 1710 and the second ball 1720 may support relative movement of the bobbin 1230 with respect to the first housing 1450.

[0141] 18 and 19 are diagrams for explaining closed-loop control of a camera module, FIG. 20 is a block diagram of a camera module according to an embodiment of the present invention, and FIGS. 21 and 22 are diagrams for explaining the control operation of a camera module according to an embodiment of the present invention.

[0142] 15 to 17, the circuit board 1330 may correspond to a drive IC, and the position sensor 1350 may correspond to a hall sensor. The position sensor 1350 may be disposed on the circuit board 1330 and electrically connected to the drive IC of the circuit board 1330. The drive IC of the circuit board 1330 may apply a current to the coil 1320.

[0143] The position sensor 1350 can sense the drive position of the bobbin 1230. For example, the position sensor 1350 can sense the position of the bobbin 1230 in the optical axis direction during AF drive in which the bobbin 1230 moves in the optical axis direction. Furthermore, for example, the position sensor 1350 can sense the position of the bobbin 1230 in a direction perpendicular to the optical axis direction during OIS drive in which the bobbin 1230 moves in a direction perpendicular to the optical axis direction. When sensing OIS drive, the position sensor 1350 can also be disposed on a circuit board below the bobbin 1230.

[0144] Referring to Figures 18 and 19, during a control operation of applying a driving signal to an actuator that drives a lens or an image sensor, a sensing signal sensed by a Hall sensor can be fed back to the driving signal generated by the AP.

[0145] More specifically, in Foreground #1 of Figure 19, the Driver IC can act as a Digital-Analog Converter (DAC) for the actuator. When a drive signal is applied to the actuator to drive it, the Hall sensor in Foreground #2 can sense the position of the actuator. The Hall sensor can sense the position of the actuator through one sensing cycle consisting of positive response sensing and negative response sensing. The Hall sensor can send a sensing signal that senses the position of the actuator to the Amplifier (AMP) of the Driver IC. The position sensing signal is amplified by the AMP and converted into a digital signal by the Analog-Digital Converter (ADC).

[0146] The position signal sensed by the Hall sensor can then be fed back to the drive signal applied to the Driver IC by the AP (Application Processor).The signal fed back by Foreground #3 is controlled by PID (Proportional Integral Derivative) and converted to a current applied to the coil by the DAC (Digital-Analog Converter).

[0147] The camera module according to this embodiment may include an actuator 211 , a position sensor 212 , a driving unit 213 and a control unit 214 .

[0148] The actuator 211 can drive at least one of a lens or an image sensor. The actuator 211 can drive the lens or the image sensor in at least one of the optical axis direction and a direction perpendicular to the optical axis. The actuator 211 can be an actuator for AF drive. The actuator 211 may be an actuator for OIS drive. The actuator 211 may be a spring-type drive actuator. The actuator 211 may be a ball-type drive actuator. The actuator 211 includes a housing and a bobbin disposed in the housing, and can drive the bobbin.

[0149] The position sensor 212 may sense the position of the actuator 211. The position sensor 212 may sense the position of the bobbin. The position sensor 212 may be a Hall sensor. The position sensor 212 may sense the position of the actuator 211 for AF feedback driving and OIS feedback driving. The position sensor 212 may correspond to, face, or overlap with a sensing magnet disposed in the actuator 211. The position sensor 212 may output a sensing signal representing the result of sensing the magnetic field strength of the sensing magnet due to movement of the bobbin to the control unit 214. The position sensor 212 may output a sensing signal representing the result of sensing the magnetic field strength of the sensing magnet due to movement of the bobbin to the driving unit 213. The position sensor 212 may be disposed in the actuator 211, and the sensing magnet may be disposed in a housing in which the actuator 211 is disposed.

[0150] The driver 213 can drive the actuator 211 based on the drive signal. The driver 213 may be a driver IC. The driver 213 may be a driver IC including the position sensor 212. The driver 213 can receive a position sensing signal sensed from the position sensor 212. The driver 213 can feed back the position sensing signal sensed by the position sensor 212 to a drive signal generated by the controller 214 and apply the resulting signal to the actuator 211. The driver 213 can apply the drive signal generated by the controller 214 to the actuator 211, and at this time, the drive signal can be a signal that reflects the feedback of the sensing signal sensed by the position sensor 212.

[0151] As described above, the driving unit 213 includes an AMP (Amplifier) ​​that amplifies the sensing signal sensed by the position sensor 212, an ADC (Analog-Digital Converter) that converts an analog signal to a digital signal, a DAC (Digital-Analog Converter) that converts a digital signal to an analog signal, and can perform PID control. The driving unit 213 may have the same configuration as the control unit 214 described later, or the driving unit 213 may have a configuration separate from the control unit 214.

[0152] The control unit 214 may generate a drive signal based on position information sensed from the position sensor 212. The control unit 214 may apply a first drive signal according to a first sensing period and then gradually increase or decrease the level of the second drive signal according to a second sensing period. Here, the sensing period may refer to an operation period including an operation in which a drive signal for position control is generated after positive and negative response sensing is performed by the position sensor 212, and the drive signal is applied to the actuator 211. The first and second sensing periods may have the same time interval. The second sensing period may be temporally consecutive with respect to the first sensing period. During the first sensing period, the first drive signal applied to the coil may not be changed, and during the second sensing period, the drive signal applied to the coil may be changed at least twice. The levels of the at least two drive signals applied to the coil during the second sensing period may be different.

[0153] Referring to (a) of FIG. 21, in conventional actuator drive control, the drive current level is applied to A in response to a first drive signal (D1), and when a second drive signal (D2) is applied, the drive current level immediately increases from A to B. Thereafter, the drive current level is maintained at B until a third drive signal (D3) corresponding to a sensing period is applied. In conventional actuator drive control methods, the drive current level changes significantly, which causes drive noise due to ball movement in ball-type drive actuators. Therefore, in order to reduce actuator drive noise, the camera module according to this embodiment controls the actuator by finely increasing or decreasing the drive current level.

[0154] 21(b), when applying the second driving signal (D2) in a state where the driving current level A is applied by the first driving signal (D1), the control unit 214 according to this embodiment can gradually increase the driving current level of the second driving signal. The control unit 214 can gradually increase the driving current level until the application of the next third driving signal (D3) in order to apply the driving current level B corresponding to the second driving signal (D2).

[0155] The control unit 214 can apply the driving current level B according to the second driving signal (D2) while the driving current level is applied to A, and can increase the driving current level M1 and M2 stepwise to be greater than A and less than B. Thereafter, when the third driving signal (D3) is applied while the driving current level according to the second driving signal (D2) is applied to B, the control unit 214 can increase or decrease the driving current level according to the third driving signal (D3) stepwise.

[0156] Since the first drive signal (D1) applies a drive current level A to the actuator 211, the magnitude of the first drive signal (D1) can be considered to be A. Since the second drive signal (D2) applies a drive current level B to the actuator 211, the magnitude of the second drive signal (D2) can be considered to be B. The drive current level can be replaced with a drive code applied to the actuator 211. The drive code can mean a coded drive current level. If the magnitude of the drive current level increases, the drive amount of the actuator 211 can be increased. If the magnitude of the drive code increases, the drive amount of the actuator 211 can be increased.

[0157] The number of steps in the level of the second drive signal applied during the second sensing period may vary depending on the difference between the level (A) of the first drive signal and the level (B) of the second drive signal. As the difference between the level (A) of the first drive signal and the level (B) of the second drive signal increases, the number of steps applied from the first drive signal to the second drive signal during the second sensing period may increase. As the level (A) of the first drive signal and the level (B) of the second drive signal decrease, the number of steps applied from the first drive signal to the second drive signal during the second sensing period may decrease.

[0158] 22, the time (t) from when the first driving signal (D1) is applied until when the second driving signal (D2) is applied may be the same as the time (t) from when the second driving signal (D2) is applied until when the third driving signal (D3) is applied. The level difference of the number of steps N may vary depending on the absolute value of the difference between the signal level A corresponding to the first driving signal (D1) and the signal level B corresponding to the second driving signal (D2).

[0159] For example, when the absolute value of the level difference between the first and second drive signals is a first value, the control unit 214 can increase or decrease the drive signal by N steps. When the absolute value of the level difference between the first and second drive signals is a second value, the control unit 214 can increase or decrease the drive signal by M steps. Here, when the first value is greater than the second value, N can be greater than M.

[0160] The difference in the step signal levels applied from the first drive signal to the second drive signal may vary depending on the difference between the level (A) of the first drive signal and the level (B) of the second drive signal. As the level (A) of the first drive signal and the level (B) of the second drive signal increase, the difference in the step signal levels applied from the first drive signal to the second drive signal may increase. As the level (A) of the first drive signal and the level (B) of the second drive signal decrease, the difference in the step signal levels applied from the first drive signal to the second drive signal may decrease.

[0161] Referring to FIG. 22, the signal level difference X, which increases or decreases in steps, can be changed depending on the absolute value of the difference between A, which is the signal level according to the first driving signal (D1), and B, which is the signal level according to the second driving signal (D2).

[0162] For example, when the absolute value of the level difference between the first drive signal and the second drive signal is a first value, the control unit 214 can increase or decrease the drive signal in steps having a level difference of X. When the absolute value of the level difference between the first drive signal and the second drive signal is a second value, the control unit 214 can increase or decrease the drive signal in steps having a level difference of Y. Here, when the first value is greater than the second value, X can be greater than Y.

[0163] The control unit 214 may control the number of steps or the level of the signal that increases or decreases for each step, taking into account the difference in current level according to the drive signal. The control unit 214 may control the number of finely controlled steps or the level of the signal that increases or decreases for each step, every time a drive signal according to a sensing period is applied. This may optimize the actuator drive for noise reduction according to the difference in level of the drive signal applied to the actuator.

[0164] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person skilled in the art to which the embodiment belongs. Therefore, content related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

Claims

1. a first switching element connecting the light emitting element and a driving power source; a second switching element connecting the light emitting element to ground; a third switching element connecting the light emitting element and a storage capacitor; and a control unit that controls operations of the first to third switching elements; The light emitting element driving module, wherein the light emitting element is charged by the driving power supply and the storage capacitor, and discharged by the ground and the storage capacitor.

2. The light-emitting element driving module according to claim 1 , further comprising an inductor disposed between the light-emitting element and the third switching element.

3. The light emitting device driving module of claim 2 , further comprising: a fourth switching element connecting the light emitting device and the storage capacitor and connected in parallel with the third switching element.

4. The control unit, when operating to cause the light emitting element to emit light, 2. The light-emitting element driving module of claim 1, wherein the third switching element is operated to be on (On) and off (Off) before the first switching element is operated to be on (On), and the third switching element is operated to be on (On) and off (Off) after the first switching element is operated to be off (Off).

5. the light-emitting element emits light when a second voltage or higher is applied; The control unit turns on the third switching element until a first voltage is applied to the light emitting element during an initial operation for light emission of the light emitting element, The light-emitting element driving module according to claim 1 , wherein the second voltage is greater than the first voltage.

6. The light-emitting element driving module according to claim 4 , wherein the control unit turns off the first switching element, and turns on the third switching element after the light-emitting element is turned off.

7. The control unit, at the time of an initial operation for light emission of the light emitting element, 2. The light-emitting element driving module of claim 1, wherein the third switching element is turned on for a first time, and after the first time, the first switching element is turned on for a second time, and after the second time, the third switching element is turned on for a third time, and after the third time, the second switching element is turned on.

8. The light-emitting element includes a plurality of light-emitting elements, The light emitting device driving module of claim 7 , wherein the control unit increases the first time period for turning on the third switching device as the number of the plurality of light emitting devices increases.

9. the light emitting element includes a parasitic capacitor; The light-emitting device driving module according to claim 1 , wherein the capacitance of the storage capacitor is 10 times or more the capacitance of the parasitic capacitor.

10. a first switching element connecting the light emitting element and a driving power source; a second switching element connecting the light emitting element to ground; a third switching element connecting the light emitting element and a storage capacitor; and a control unit that controls operations of the first to third switching elements; The control unit turns on the third switching element before turning on the first switching element, thereby charging the energy of the storage capacitor to the light emitting element.

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