Light-emitting device driving module and camera module

Abstract

The light emitting device driving module according to an embodiment of the present invention comprises: a first switching device connecting a light emitting device to a driving power supply; a second switching device connecting the light emitting device to a ground; a third switching device connecting the light emitting device to a storage capacitor; and a controller controlling operation of the first to third switching devices, in which charging of the light emitting device is performed through the driving power supply and the storage capacitor, and discharging of the light emitting device is performed through the ground and the storage capacitor.

Description

Technical Field

[0001] The present disclosure relates to a light emitting device driving module and a camera module. Background Art

[0002] A VCSEL (Vertical-Cavity Surface-Emitting Laser) is a semiconductor laser device that emits laser light in a direction perpendicular to the surface of a semiconductor wafer in the field of optical communication. Recently, due to miniaturization, high integration, low power consumption, simple manufacturing process, and heat resistance, the interest in VCSEL technology is increasing. In addition, it is easy to connect to a photoreceptor or an optical fiber, and since two-dimensional arrangement is easy, parallel signal processing is possible, and it can be integrated with digital and analog circuits using existing semiconductor processes, so the technical application fields are constantly expanding.

[0003] A VCSEL driving device for driving these VCSELs must be able to stably supply a bias current signal and generate a modulation current signal at a high operating frequency in order to effectively provide a stable bandwidth and high gain at the optical transmitter end. Existing laser driving devices use BJT (Bipolar Junction Transistor) processes or SiGe or BiCMOS process technologies. However, recently, in order to achieve low power and low production cost, it is necessary to develop a VCSEL driving device based on pure CMOS technology that can achieve high productivity and high integration.

[0004] As digital cameras such as digital still cameras and digital video cameras become more and more common, consumers' expectations for taking high-quality photos and videos are increasing.

[0005] In the case where a camera captures video and still images, there are many situations where unstable and shaky images are captured due to external factors of the camera such as hand jitter or external vibrations from vehicle mounting.

[0006] In order to prevent the resolution of a photo from deteriorating due to external vibrations or jitter of a digital imaging device such as user hand shake, recently, the number of cameras combined with a shake compensation device is increasing. Summary of the Invention

[0007] Technical Problem

[0008] The technical problem to be solved by the present disclosure is to provide a light emitting device driving module and a camera module that compensates for moving tilt afterwards.

[0009] Technical Solution

[0010] To solve the above technical problems, a light-emitting device driving module includes: a first switching device connected to the light-emitting device and a driving power source; a second switching device connected to the light-emitting device and a ground portion; a third switching device connected to the light-emitting device and a storage capacitor; and a controller configured to control operations of the first to third switching devices, wherein the light-emitting device can be charged by the driving power source and the storage capacitor and discharged through the ground portion and the storage capacitor.

[0011] The light-emitting device driving module may further include an inductor disposed between the light-emitting device and the third switching device.

[0012] The light-emitting device driving module may further include a fourth switching device connected to the light-emitting device and the storage capacitor and connected in parallel with the third switching device.

[0013] When operating the light-emitting device for light emission, the controller may turn on and off the third switching device before turning on the first switching device and turn on and off the third switching device after turning off the first switching device.

[0014] If a second voltage or higher voltage is applied to the light-emitting device, the light-emitting device may operate to emit light. During an initial operation for light emission, the controller may turn on the third switching device until a first voltage is applied to the light-emitting device, and the second voltage may be greater than the first voltage.

[0015] The controller may turn off the first switching device to extinguish the light-emitting device and then turn on the third switching device.

[0016] During an initial operation in which the light-emitting device emits light, the controller may turn on the third switching device for a first period of time, turn on the first switching device for a second period of time after the first period of time, turn on the third switching device for a third period of time after the second period of time, and turn on the second switching device after the third period of time.

[0017] The light-emitting device may include a plurality of light-emitting devices, and the controller may increase the first period of time for turning on the third switching device as the number of the plurality of light-emitting devices increases.

[0018] The light-emitting device may include a parasitic capacitor, and the capacitance of the storage capacitor may be more than 10 times the capacitance of the parasitic capacitor.

[0019] A light-emitting device driving module includes: a first switching device connected to the light-emitting device and a driving power source; a second switching device connected to the light-emitting device and a grounding portion; a third switching device connected to the light-emitting device and a storage capacitor; and a controller for controlling the operations of the first to third switching devices, wherein the controller may turn on the third switching device before turning on the first switching device to charge the energy of the storage capacitor to the light-emitting device.

[0020] The light-emitting device includes a plurality of light-emitting devices, and the controller may increase the time for turning on the third switching device as the number of the plurality of light-emitting devices increases.

[0021] The controller may charge the energy of the light-emitting device into the storage capacitor by turning on the third switching device after the turn-off operation of the first switching device.

[0022] The controller may release the energy of the light-emitting device to the grounding portion by turning on the second switching device after the turn-off operation of the third switching device.

[0023] An inductor may be included between the light-emitting device and the third switching device.

[0024] The light-emitting device includes a parasitic capacitor, and the capacitance of the storage capacitor may be at least 10 times the capacitance of the parasitic capacitor.

[0025] To solve the above technical problems, a camera module according to an embodiment of the present disclosure includes: an image sensor; a first driving actuator disposed on the image sensor for driving OIS; a driving unit for applying a driving signal to the first driving actuator; and a controller for generating a driving signal for driving the first driving actuator to correct a movement tilt that occurs when at least one of a driving zoom drive and an AF drive is performed, wherein the controller may store, as a pixel movement amount sensitivity on the image sensor, a driving amount of the first driving actuator, and the controller may generate the driving signal applied to the first driving actuator using the pixel movement amount and the sensitivity.

[0026] The sensitivity includes: a first sensitivity, which is a pixel movement amount on the image sensor according to a driving amount in a first axis direction perpendicular to the optical axis direction of the first driving actuator; and a second sensitivity, which is a pixel movement amount on the image sensor according to a driving amount in a second axis direction perpendicular to the optical axis direction of the first driving actuator, and the first axis direction and the second axis direction may be perpendicular.

[0027] The camera module may include a second driving actuator for zoom driving, and the controller may store the amount of pixel movement on the image sensor caused by the movement tilt occurring during the zoom driving.

[0028] The camera module may include a third driving actuator for AF driving, and the controller may store the amount of pixel movement on the image sensor caused by the movement tilt occurring during the AF driving.

[0029] The camera module may include a second driving actuator for zoom driving; and a third driving actuator for AF driving, and the controller may simultaneously store the amount of pixel movement on the image sensor caused by the movement tilt occurring during the zoom driving and the AF driving.

[0030] To solve the above technical problems, according to another embodiment of the present disclosure, a camera module includes: an image sensor; a first driving actuator disposed on the image sensor for OIS driving; a second driving actuator for zoom driving; a third driving actuator for AF driving; a driving unit that applies driving signals to the first to third driving actuators; and a controller that generates a first driving signal for driving the first driving actuator to correct the movement tilt occurring during the driving of at least one of the zoom driving and the AF driving, wherein the controller may store the sensitivity as the amount of pixel movement on the image sensor according to the driving amount of the first driving actuator, and the controller may generate the driving signal applied to the first driving actuator using the pixel movement amount and the sensitivity.

[0031] The controller may store the amount of pixel movement on the image sensor according to the second driving signal applied to the second driving actuator and the amount of pixel movement on the image sensor according to the third driving signal applied to the third driving actuator.

[0032] The above controller may generate a first driving signal according to the second driving signal and the third driving signal.

[0033] The sensitivity includes: a first sensitivity, which is the amount of pixel movement on the image sensor according to the driving amount in a first axis direction perpendicular to the optical axis direction of the first driving actuator; and a second sensitivity, which is the amount of pixel movement on the image sensor according to the driving amount in a second axis direction perpendicular to the optical axis direction of the first driving actuator, and the first axis direction and the second axis direction may be perpendicular.

[0034] The first sensitivity and the second sensitivity may have different slopes.

[0035] To solve the above technical problems, a camera module according to an embodiment of the present disclosure includes: a housing and a bobbin disposed in the housing; an actuator for driving the bobbin; a position sensor for sensing the position of the bobbin; a driving unit for applying a driving signal to the actuator; and a controller for generating a driving signal based on the position sensed by the position sensor, wherein when a second driving signal is applied according to a second sensing period after a first driving signal is applied according to a first sensing period, the controller can gradually increase or decrease the level of the second driving signal.

[0036] The number of steps of the level of the second driving signal applied during the second sensing period can vary according to the difference between the level of the first driving signal and the level of the second driving signal.

[0037] When the absolute value of the level difference between the first driving signal and the second driving signal is a first value, the controller increases or decreases the steps of the level of the second driving signal applied during the second sensing period by N steps, and when the absolute value of the level difference between the first driving signal and the second driving signal is a second value, the controller increases or decreases the steps of the level of the second driving signal applied during the second sensing period by M steps, and when the first value is greater than the second value, N can be greater than M.

[0038] When the absolute value of the level difference between the first driving signal and the second driving signal is a first value, the controller increases or decreases the driving signal to steps having a level difference X, and when the absolute value of the level difference between the first driving signal and the second driving signal is a second value, the controller increases or decreases the driving signal to steps having a level difference Y, and when the first value is greater than the second value, X can be greater than Y.

[0039] To solve the above technical problems, a camera module according to an embodiment of the present disclosure includes: a housing; a bobbin disposed in the housing; a ball disposed between the bobbin and the housing; a magnet disposed on the bobbin; a coil disposed to face the magnet; a position sensor disposed to face the magnet; a driving unit for applying a driving signal to the coil; and a controller for generating a driving signal based on the position sensed by the position sensor, wherein when a second driving signal is applied according to a second sensing period after a first driving signal is applied according to a first sensing period, the controller can gradually increase or decrease the level of the second driving signal.

[0040] The second sensing period can be continuous in time relative to the first sensing period.

[0041] The first sensing period and the second sensing period can have the same time interval.

[0042] During the first sensing period, the first driving signal applied to the coil may remain unchanged. During the second sensing period, the driving signal applied to the coil may change at least twice.

[0043] Advantageous Effects

[0044] According to an embodiment of the present invention, the energy remaining after light emission in a light-emitting device is stored in a capacitor without being released, and when light emission is performed again, the energy stored in the capacitor is used as a bias voltage, so that energy consumption can be reduced, and this is advantageous in terms of efficient energy management.

[0045] In addition, since the amount of energy charged in the capacitor can be controlled by using LC resonance, high-speed light-emitting driving is possible even when the number of light-emitting devices increases.

[0046] In addition, even when the number of light-emitting devices changes and the magnitude of the bias voltage required for light emission changes, the amount of bias voltage required for the light-emitting device can be applied by controlling the switching time. Therefore, it is not necessary to change the design of the light-emitting device driving module every time the number of light-emitting devices changes.

[0047] According to this embodiment, the movement tilt caused by a long stroke during zoom driving or AF driving can be improved.

[0048] In addition, by pre-calibrating a zoom driving actuator, an AF driving actuator, and an OIS driving actuator having different dimensional systems based on an image sensor, the movement tilt can be improved more immediately.

[0049] According to this embodiment, the noise generated during the operation of the spherical actuator can be reduced by fine control.

[0050] In addition, the driving control of the actuator can be optimized by flowingly changing the number of steps and the signal magnitude of each step according to the magnitude of the driving signal applied to the actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a circuit diagram showing a light-emitting device driving module.

[0052] Figure 2 is a view for explaining the operation of the light-emitting device driving module.

[0053] Figure 3 is a block diagram showing a light-emitting device driving module according to this embodiment.

[0054] Figure 4 and Figure 5 is a circuit diagram showing a light-emitting device driving module according to this embodiment.

[0055] Figure 6 is a view for explaining the operation of the light emitting device driving module according to the present embodiment.

[0056] Figure 7 is a circuit diagram showing a light emitting device driving module according to another embodiment of the present disclosure.

[0057] Figure 8 is a view for explaining the operation in which a resonance phenomenon occurs when energy is charged from a storage capacitor to a light emitting device according to the present embodiment.

[0058] Figure 9 and Figure 10 is a circuit diagram showing a light emitting device driving module according to another embodiment of the present disclosure.

[0059] Figure 11 is a block diagram showing a camera module according to the present embodiment.

[0060] Figure 12 is a block diagram showing a camera module according to another embodiment of the present disclosure.

[0061] Figure 13 is a sensitivity curve graph stored in a controller of a camera module according to the present embodiment.

[0062] Figure 14 is a view for explaining the moving tilt compensation operation of a camera module according to the present embodiment.

[0063] Figure 15 is an exploded perspective view showing a lens driving device according to an embodiment of the present disclosure.

[0064] Figure 16 is an exploded perspective view showing a lens driving device according to another embodiment of the present disclosure.

[0065] Figure 17 is an exploded perspective view of a lens driving device according to another embodiment of the present disclosure.

[0066] Figure 18 and Figure 19 is a view for explaining the closed loop control of a camera module.

[0067] Figure 20 is a block diagram showing a camera module according to an embodiment of the present disclosure.

[0068] Figure 21 and Figure 22 is a view for explaining the control operation of a camera module according to an embodiment of the present disclosure. Detailed Description

[0069] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0070] However, the technical concept of the present disclosure is not limited to the described embodiments, but can be implemented in various different forms, and within the scope of the technical concept of the present disclosure, one or more components in the embodiments can be selectively combined or used alternatively.

[0071] In addition, unless clearly and specifically defined and described, the terms (including technical terms and scientific terms) used in this embodiment can be interpreted as having the meanings that are generally understood by those of ordinary skill in the technical field to which this embodiment belongs, and the commonly used terms such as those defined in a dictionary can have their meanings interpreted in consideration of the context of the related technology.

[0072] In addition, the terms used in this embodiment are for the purpose of describing the embodiment and are not intended to limit the present disclosure.

[0073] In this specification, unless otherwise specifically stated in a phrase, the singular may also include the plural, and when described as "at least one (one or more) of A, B, C", it can include one or more of all combinations that can be combined with A, B, C.

[0074] In addition, when describing the components of this embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components and are not intended to limit the nature, order, or sequence of the components.

[0075] In addition, when a component is described as "connected", "coupled", or "contacted" with another component, it may include not only the case where the component is directly "connected", "coupled", or "contacted" with the other component, but also the case where the component is "connected", "coupled", or "contacted" by other components between the component and the other component.

[0076] In addition, when described as formed or arranged "above" or "below" each component, "above" or "below" includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or arranged between the two components. In addition, when expressed as "above" or "below", it may include the meanings of the downward direction and the upward direction based on one component.

[0077] The "optical axis direction" used hereinafter is defined as the optical axis direction of the lens and / or the image sensor coupled to the lens driving device.

[0078] The "vertical direction" used below may be a direction parallel or identical to 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. In other words, 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".

[0079] The "auto-focus (AF) function" used below is defined as the following function: adjusting the distance from the image sensor by moving the lens in the optical axis direction according to the distance of the object, so as to automatically focus on the object, so that a clear image of the object can be obtained on the image sensor. In addition, the "auto-focus feedback (CLAF, closed-loop auto-focus) control" is defined as detecting the distance between the image sensor and the lens and controlling the position of the lens in real time through feedback to improve the accuracy of focus adjustment.

[0080] The "handshake correction (optical image stabilization (OIS) function)" used below is defined as a function of moving or tilting the lens in a direction perpendicular to the optical axis to cancel hand shake in order to prevent image or image shake caused by the user's hand shake. In addition, the "handshake correction feedback control" is defined as detecting the position of the lens relative to the image sensor and controlling the position of the lens in real time through feedback to improve the accuracy of handshake correction.

[0081] Figure 1 is a circuit diagram showing a light-emitting device driving module, Figure 2 is a view for explaining the operation of the light-emitting device driving module.

[0082] A VCSEL (vertical cavity surface emitting laser) is a light-emitting device, which is a semiconductor laser device that emits laser light in a vertical direction from the surface of a semiconductor wafer in the field of optical communication. The light-emitting device may be an LED (light-emitting diode).

[0083] The circuit for driving the light-emitting device may include a first switching device S1 for controlling the application of a driving power supply and a second switching device S2 for controlling the connection to ground. Refer to Figure 2 , when a voltage equal to or higher than the Vf value is applied, the light-emitting device can emit light, and when a voltage equal to or lower than the Vf value is applied, the light-emitting device can be turned off. This can be regarded as including a switch Sd in the light-emitting device, which is turned on when the voltage applied to the light-emitting device is equal to or higher than the Vf value and turned off when the voltage applied to the light-emitting device is equal to or lower than the Vf value.

[0084] When the light-emitting device is initially driven to emit light, the first switching device S1 is turned on to increase the voltage applied to the light-emitting device. At this time, a rise time Tr (rising time) is required, which is the time from when the first switching device S1 is turned on to when the light-emitting device emits light. As the rise time increases, even when the driving power supply is applied, the period during which the light-emitting device does not emit light increases, resulting in a problem of unnecessary consumption of energy X.

[0085] Thereafter, when the first switching device S1 is turned off and the voltage applied to the light-emitting device becomes equal to or lower than Vf, the light-emitting device is turned off. After the first switching device S1 is turned off and the dead time has passed, the second switching device S2 is turned on to release the remaining energy Y in the light-emitting device to the ground portion. In other words, the remaining energy Y in the light-emitting device is wasted without being used for light emission, so there is a problem in terms of effective energy management.

[0086] Figure 3 is a block diagram showing a light-emitting device driving module according to the present embodiment, Figure 4 and Figure 5 is a circuit diagram showing a light-emitting device driving module according to the present embodiment, Figure 6 is a view for explaining the operation of the light-emitting device driving module according to the present embodiment, Figure 7 is a circuit diagram showing a light-emitting device driving module according to another embodiment of the present disclosure, Figure 8 is a view for explaining the operation in which a resonance phenomenon occurs when energy is charged from a storage capacitor to a light-emitting device according to the present embodiment, and Figure 9 and Figure 10 is a circuit diagram showing a light-emitting device driving module according to another embodiment of the present disclosure.

[0087] The light-emitting device driving module 100 according to the present embodiment may include a circuit unit 110 connected to the light-emitting device 1 and a controller 120 for controlling the circuit unit 110. The controller 120 may control the circuit unit 110 to control the light 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 driver or a light-emitting device driving IC.

[0088] One end of the light-emitting device D may be connected to the circuit unit 110, and the other end thereof may be grounded. For example, the light-emitting device D may be a VCSEL (Vertical-Cavity Surface-Emitting Laser) or an LED (Light-Emitting Diode).

[0089] The light-emitting device D may include a parasitic capacitor Cd and an internal resistor Rd therein. Referring to Figure 5 , the parasitic capacitor Cd and the internal resistor Rd are connected in parallel with the light-emitting device D, and the parasitic switch Sd is connected in series, but this is shown for ease of explanation, and in fact, it may be a configuration included inside the light-emitting device D.

[0090] The circuit unit 110 may include a first switching device S1 connecting the light-emitting device D and the driving power supply VDD, a second switching device S2 connecting the light-emitting device D and the grounding portion, and a third switching device S3 connecting the light-emitting device D and the storage capacitor Cs. The first switching device S1, the second switching device S2, and the third switching device S3 may be any one of a switch, a relay, and a MOSFEF.

[0091] Resistors may be connected to each of the first switching device S1, the second switching device S2, and the third switching device S3. The resistors connected to the switching devices may be connected to prevent short circuits. The resistors connected to the switching devices have a large resistance value and can prevent overcurrent, and may have a value of, for example, 1 kΩ to 10 kΩ.

[0092] The controller 120 may control the operations of the first switching device S1, the second switching device S2, and the third switching device S3. The controller 120 may control the first switching device S1, the second switching device S2, and the third switching device S3 to be turned on or off. Here, the turn-on operation means a short circuit, where the switch is connected and current flows through the circuit, and the turn-off operation means an open circuit, where the switch is not connected and current does not flow through the circuit.

[0093] Referring to Figure 6 , when a voltage equal to or higher than the second voltage V2 is applied, the light-emitting device D may emit light, and when a voltage equal to or lower than the second voltage V2 is applied, the light-emitting device may be extinguished. This means that the light-emitting device includes a parasitic switch Sd that is turned on when the applied voltage is equal to or higher than the second voltage V2 and turned off when the voltage is equal to or lower than the second voltage V2. In other words, when the potential of the light-emitting device D is equal to or higher than the second voltage V2, the parasitic switch Sd may be automatically turned on, and when the potential of the light-emitting device D is equal to or lower than the second voltage V2, the parasitic switch Sd may be automatically turned off.

[0094] Referring to Figure 6 , the light-emitting and extinguishing operations of the light-emitting device D may be achieved in an operation mode composed of sections A to H.

[0095] In section A, the third switching device S3 can be turned on so that the energy X stored in the storage capacitor Cs can be charged to the light-emitting device D. Through the turn-on operation of the third switching device S3, the energy X stored in the storage capacitor Cs can be charged to the parasitic capacitor Cd of the light-emitting device D. At this time, the third switching device S3 can be turned on until the potential of the light-emitting device D becomes the first voltage V1. The energy actually stored in the storage capacitor Cs can be greater than the energy X charged to the light-emitting device D through the turn-on operation of the third switching device S3. As the turn-on time of the third switching device S3 increases, the energy X charged from the storage capacitor Cs to the light-emitting device D can increase. The first voltage V1 applied to the light-emitting device D can be used as a bias voltage.

[0096] The capacitance of the storage capacitor Cs can be more than 10 times the capacitance of the parasitic capacitor Cd of the light-emitting device D. When 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 can be charged to the parasitic capacitor Cd. Conversely, when 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 can be charged to the storage capacitor Cs. When, in section G described below, after the light-emitting device D emits light, the remaining energy in the parasitic capacitor Cd is charged to the storage capacitor Cs, since the capacitance of the storage capacitor Cs is sufficiently greater than the capacitance of the parasitic capacitor Cd of the light-emitting device D, from the perspective of the parasitic capacitor Cd, the energy can be charged to the storage capacitor Cs as if it were grounded.

[0097] Section B can be the section before the third switching device S3 is turned off and the first switching device S1 is turned on. After section B, in section C, the first switching device S1 is turned on and the drive power supply VDD is applied. According to the turn-on time of the first switching device S1, the voltage applied to the light-emitting device D can increase from the first voltage V1 to the third voltage V3. According to the turn-on time of the first switching device S1, the voltage applied to the light-emitting device D can increase linearly. In section C, when the voltage applied to the light-emitting device D increases from the first voltage V1 to the third voltage V3 and reaches the second voltage V2 at which the parasitic switch Sd is turned on, some energy is used to turn on the parasitic switch Sd, so there may be a temporary section where the voltage does not increase.

[0098] The rise time Tr is the time from when the driving power supply VDD is applied to the light-emitting device D until the light-emitting device D emits light, and it can be the time when the voltage increases from the first voltage V1 to the second voltage V2. The conventional rise time Tr is the time when the voltage applied to the light-emitting device D increases from 0V to the second voltage V2. However, according to this embodiment, since the energy already stored in the storage capacitor Cs in section A is charged to the light-emitting device D and the voltage increases to the first voltage V1, the rise time Tr can be shortened. Thus, the light-emitting device D can emit light at high speed based on the time when the driving power supply VDD is applied, and the energy consumption can be reduced. In other words, the light-emitting device D can emit light at high speed based on the time when the first switching device S1 is turned on.

[0099] In section D, when the voltage applied to the light-emitting device D is equal to or higher than the second voltage V2, the light-emitting device D can emit light through the turn-on operation of the parasitic switch Sd. The luminous intensity of the light-emitting device D can gradually increase as the applied voltage increases, and can gradually decrease as the applied voltage decreases. The rated voltage that can be applied to the light-emitting device D can be the third voltage V3. The light-emitting device D can emit light at the maximum brightness at the third voltage V3.

[0100] In section E, the first switching device S1 is turned off, and the voltage applied to the light-emitting device D can be reduced. In this section, the voltage applied to the light-emitting device D gradually decreases from the maximum voltage, the third voltage V3, but is greater than the second voltage V2, so that the parasitic switch Sd can maintain the turn-on operation. In other words, in section E, even when the first switching device S1 is turned off, the parasitic switch Sd can still maintain the turn-on operation, and the light-emitting device D can emit light with a brightness lower than the maximum brightness, but can gradually go out.

[0101] In section F, since the voltage applied to the light-emitting device D becomes lower than the second voltage V2, the parasitic switch Sd is turned off. Since some energy is also used for the turn-off operation of the parasitic switch Sd, there may be a temporary section where the voltage applied to the light-emitting device D does not decrease. Since sections E and F are the sections where the turn-on or turn-off operations of the first switching device S1 and the third switching device S3 intersect, they can be dead time sections where both switches are turned off so that neither switch is turned on. Since section F is the section where the turn-on or turn-off operations of the parasitic switch Sd and the third switching device S3 intersect, they can be dead time sections where both switches are turned off so that neither switch is turned on.

[0102] In section G, the third switching device S3 can be turned on to connect the light-emitting device D to the storage capacitor Cs. Through the turn-on operation of the third switching device S3, the light-emitting device D emits light, and the remaining energy Y can be charged to the storage capacitor Cs. Through the turn-on operation of the third switching device S3, the remaining energy Y in the parasitic capacitor Cd after the light-emitting device 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 as the energy for charging the parasitic capacitor Cd in section A that will perform a light-emitting operation later.

[0103] In section H, the second switching device S2 can be turned on to connect the light-emitting device D to the ground. Although not shown, a dead time section may be included between section G and section H because this is the section where the turn-on or turn-off operations of the second switching device S2 and the third switching device S3 intersect. In this dead time section, a surge current generated by the turn-on operation of the second switching device S2 may occur.

[0104] Observing the entire operation of sections A to H, that is, the light-emitting and extinguishing operations of the light-emitting device D, before the turn-on operation of the first switching device S1 for connecting the driving power supply VDD to the light-emitting device D, the energy stored in the storage capacitor Cs can be charged to the light-emitting device D by turning on and off the third switching device S3. Thus, the first voltage V1 as a bias voltage can be applied to the light-emitting device D. The first voltage V1 can be a value lower than the second voltage V2 required for the light-emitting device D to emit light. Thereafter, after the turn-on operation of the first switching device S1, the third switching device S3 is turned on and off so that the remaining energy in the light-emitting device D after light emission can be charged to the storage capacitor Cs.

[0105] The controller 120 can turn on the third switching device S3 for a first time period during the initial operation for the light-emitting device D to emit light, turn on the first switching device S1 for a second time period after the first time period, turn on the third switching device S3 for a third time period after the second time period, and turn on the second switching device S2 for a third time period after the third time period. Here, the first time period can refer to the time period for applying the first voltage V1 lower than the second voltage V2 to the light-emitting device D. The second time period can be the time period for the light-emitting device D to emit light. The third time period can be the time period for charging the remaining energy of the light-emitting device D to the storage capacitor Cs after light emission.

[0106] Refer to Figure 7 As shown in, the circuit unit 110 can further include an inductor L disposed between the light-emitting device D and the third switching device S3. Thus, when charging the energy stored in the storage capacitor Cs to the light-emitting device D, the energy can be amplified and charged through the resonance phenomenon between the inductor L and the storage capacitor Cs. Refer to Figure 8, since the peak time when the voltage is amplified to the maximum during resonance is calculated as Therefore, the time to turn on the third switching device S3 can be adjusted in consideration of this.

[0107] Referring to Figure 9 , the circuit unit 110 may further include a fourth switching device that connects the light-emitting device D and the storage capacitor Cs and is connected in parallel with the third switching device S3. The controller 120 can turn on the third switching device S3 when charging the light-emitting device D by connecting the storage capacitor Cs and the inductor L, and can turn on the fourth switching device S4 when charging the light-emitting device D without connecting the inductor L.

[0108] Referring to Figure 10 , the light-emitting device D may include a plurality of light-emitting devices D1, D2, D3, and D4. The light-emitting device D can be connected to the light-emitting device driving module 100 and increased or decreased according to the required brightness. As the number of light-emitting devices D increases, the magnitude of the power required to drive the light-emitting device D can increase. Therefore, as the number of light-emitting devices D increases, the magnitude of the driving energy must increase.

[0109] Even if the number of light-emitting devices D changes, the light-emitting device driving module 100 according to the present embodiment can control the on-operation time of the third switching device S3 to cause the light-emitting device D to emit light without changing the existing design and without changing the magnitude of the driving power supply VDD. 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 device D, can increase. Therefore, it is necessary to increase the magnitude of the first voltage V1 according to the increased third voltage V3. Since the first voltage V1 is formed by charging the light-emitting device D with the energy stored in the storage capacitor Cs, the controller 120 can increase the magnitude of the first voltage V1 by increasing the connection time between the storage capacitor Cs and the light-emitting device D. As the number of light-emitting devices increases, the controller 120 can increase the time to turn on the third switching device S3. Additionally, in the case of the light-emitting device driving module 100 where an inductor L is connected between the third switching device S3 and the light-emitting device D, the controller 120 can increase the voltage through the inductor L and charge the light-emitting device D. Specifically, since the peak time for amplifying to the maximum voltage when resonance occurs through the inductor L and the storage capacitor Cs is calculated as Therefore, the time to turn on the third switching device S3 can be adjusted in consideration of this.

[0110] According to the present embodiment, since the energy remaining after light emission in the light-emitting device is stored in the capacitor without being released, and the energy stored in the capacitor is used as a bias voltage when light emission occurs again, energy consumption can be reduced, which is advantageous in terms of efficient energy management. In addition, since LC resonance can be used to adjust the magnitude of the energy charged in the capacitor, even when the number of light-emitting devices increases, light emission can be driven at high speed. Further, even when the number of light-emitting devices changes and the magnitude of the bias voltage required for light emission changes, the bias voltage of the light-emitting devices can be applied as much as possible by controlling the switching time. Therefore, it is not necessary to change the design of the light-emitting device driving module every time the number of light-emitting devices changes.

[0111] As described above, the light-emitting device driving module according to the embodiment of the present disclosure has been described with reference to Figures 1 to 10 Hereinafter, a camera module according to an embodiment of the present disclosure will be described with reference to Figures 11 to 14 The camera module according to the embodiment of the present disclosure, the light-emitting device driving module according to the embodiment of the present disclosure, and the detailed descriptions of their names, terms, and functions are based on the detailed descriptions of each embodiment and may be the same as or different from each other.

[0112] Figure 11 is a block diagram showing a camera module according to the present embodiment, Figure 12 is a block diagram showing a camera module according to another embodiment of the present disclosure, Figure 13 is a sensitivity curve graph stored in a controller of a camera module according to the present embodiment, Figure 14 is a view for explaining a moving tilt compensation operation of a camera module according to the present embodiment.

[0113] During mass production of camera modules, the autofocus characteristics of each mass-produced camera module may vary due to lens deviation of the actuator, actuator dynamic characteristic deviation, actuator electrical characteristic deviation, and assembly deviation within the camera module. In the case of an actuator that drives AF and zoom, a moving tilt phenomenon occurs in which the target moves when operating with a long stroke. To compensate for this, it is necessary to drive an OIS driving actuator that drives in a direction perpendicular to the optical axis.

[0114] However, since AF driving and zoom driving mean driving a lens or an image sensor in the direction of the optical axis, while OIS driving means driving in a direction perpendicular to the optical axis, there is a problem that even if a moving tilt occurs due to AF driving and zoom driving, it is not known how much moving tilt should be compensated by OIS driving.

[0115] The present disclosure is to solve these problems, and according to this embodiment, the pixel movement amount of the image sensor according to the driving amount of the OIS driving actuator can be pre-calibrated, and when a movement tilt occurs, an OIS driving signal can be generated by the pixel movement amount of the target movement on the image sensor. In other words, since the AF driving actuator, the zoom driving actuator, and the OIS driving actuator have different dimensions, the movement tilt can be corrected by a method of pre-calibrating the two driving systems based on the pixel movement amount of the image sensor.

[0116] The camera module according to this embodiment may include an image sensor, a first driving actuator 11, a driving unit 12, and a controller 13. The camera module according to another embodiment of the present disclosure 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 controller 13.

[0117] The first driving actuator 11 is an actuator for driving OIS. The first driving actuator 11 may be placed on the image sensor. The OIS driving may refer to driving the lens or the image sensor in a direction perpendicular to the optical axis. The OIS driving actuator may be referred to as a shake correction actuator.

[0118] The second driving actuator 14 is an actuator for zoom driving. The zoom driving may refer to continuous zoom driving. The zoom driving may refer to moving at least one of a plurality of lens groups included in the optical system in the optical axis direction.

[0119] The third driving actuator 15 is an actuator for AF driving. The AF driving may refer to fixed zoom driving. The AF driving may refer to driving the lens or the image sensor in the optical axis direction for focus adjustment.

[0120] When driving the lens, the first driving actuator 11 to the third driving actuator 15 may be referred to as a lens driving device. When driving the image sensor, the first driving actuator 11 to the third driving actuator 15 may be referred to as a sensor driving device.

[0121] The driving unit 12 may apply a driving signal to the first driving actuator 11. The driving unit 12 may apply driving signals to the first driving actuator 11 to the third driving actuator 15. The driving unit 12 may apply a first driving signal to the first driving actuator 11. The driving unit 12 may apply a second driving signal to the second driving actuator 14. The driving unit 12 may apply a third driving signal to the third driving actuator 15. The driving unit 12 may be in the form of a driver IC.

[0122] The controller 13 may generate a driving signal applied to the first driving actuator 11 to compensate for the movement tilt that occurs during at least one of the zoom driving and the AF driving. The controller 13 may generate a driving signal applied to the first driving actuator 11 based on the amount of pixel movement on the image sensor due to the movement tilt.

[0123] The controller 13 may store a sensitivity that is the amount of pixel movement on the image sensor according to the driving amount of the first driving actuator 11. The controller 13 may generate a driving signal applied to the first driving actuator 11 using the amount of pixel movement and the sensitivity. The sensitivity may be "the relationship between the driving amount of the first driving actuator 11 and the amount of pixel movement on the image sensor". The sensitivity may be "the driving amount of the first driving actuator 11 and the amount of pixel movement on the image sensor represented in the form of a look-up table (LUT)". The controller 13 may store the driving amount of the first driving actuator 11 according to the amount of pixel movement on the image sensor. The driving amount of the first driving actuator 11 may mean the magnitude of the driving current applied to the first driving actuator 11. The driving amount of the first driving actuator 11 may mean the magnitude of the driving code applied to the first driving actuator 11. The driving amount of the first driving actuator 11 may mean the magnitude of the signal applied to the first driving actuator 11 to move the lens or the image sensor in the x-axis direction or the y-axis direction perpendicular to the optical axis direction (z-axis).

[0124] When the movement tilt occurs, the sensitivity is pre-calibrated because it is impossible to determine how much the first driving actuator 11 must move to move to the original target on the image sensor. After that, when the target on the image sensor moves due to the movement tilt, the driving amount of the first driving actuator 11 may be calculated based on the amount of pixel movement on the image sensor.

[0125] The sensitivity may include a first sensitivity that is the amount of pixel movement on the image sensor according to the 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 that is the amount of pixel movement on the image sensor according to the 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 represent the x-axis direction, and the second axis direction may represent the y-axis direction.

[0126] Refer to Figure 13, the first sensitivity may have a first slope in a graph with the x-axis representing "x-axis driving amount" and the y-axis representing "x-axis pixels". The second sensitivity may have a second slope in a graph with the x-axis representing "y-axis driving amount" and the y-axis representing "y-axis pixels". 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 pre-calibrated and stored. Although Figure 13 shows a linear relationship between the "driving amount of the first driving actuator 11" and the "amount of pixels on the image sensor", it is not limited thereto, and obviously it can vary according to the characteristics of the actuator arranged in the camera module.

[0127] Referring to Figure 14 (a), before the AF driving or zoom driving operation, the target 1 may be located in the central region of the image sensor. Referring to Figure 14 (b), when the AF driving or zoom driving is performed, a moving tilt occurs. Based on the target 2 which is the center of the image sensor, the target 1 moves Δx in the x-axis direction and Δy in the y-axis direction.

[0128] Therefore, it is necessary to correct the position of the moving tilt target 1 to the position of the target 2 by driving the first driving actuator 11 of the OIS. The controller 13 calculates (Δx, Δy) which is the amount of pixel movement on the image sensor according to the target movement, and can calculate the x-axis driving amount and the y-axis driving amount of the first driving actuator 11 through (Δx, Δy) and the first sensitivity and the second sensitivity that have been pre-calibrated.

[0129] The controller 13 may store the amount of pixel movement on the image sensor due to the moving tilt that occurs when driving the zoom. The controller 13 may store the amount of pixel movement on the image sensor due to the moving tilt that occurs when driving the AF. The controller 13 may store the amount of pixel movement on the image sensor due to the moving tilt that occurs when driving the zoom and driving the AF simultaneously.

[0130] The controller 13 may store the amount of pixel movement on the image sensor according to the second driving signal applied to the second driving actuator 14. The controller 13 may store the amount of pixel movement on the image sensor according to the third driving signal applied to the third driving actuator 15. The controller 13 may store the amount of pixel movement on the image sensor that occurs when the second driving signal is applied to the second driving actuator 14 and at the same time the third driving signal is applied to the third driving actuator 15.

[0131] When the second driving actuator 14 for zoom driving and the third driving actuator 15 for AF driving perform a stroke operation, the moving tilt that occurs due to dynamic characteristic deviations of the actuators, electrical characteristic deviations of the actuators, assembly deviations of the actuators within the camera module, etc. can be constant. For example, when the second driving actuator 14 performs a stroke operation with a length of A, a moving tilt with a target moving length of B may always occur. Or, when the third driving actuator 15 performs a stroke operation with a length of C, a moving tilt with a target moving length of D may always occur.

[0132] Therefore, if the amount of pixel movement on the image sensor due to the moving tilt that occurs during zoom driving and the amount of pixel movement on the image sensor due to the moving tilt that occurs during AF driving are pre-calibrated, the driving amount of the first driving actuator 11 can be calculated more quickly without directly checking the amount of pixel movement on the image sensor.

[0133] The controller 13 can generate a first driving signal based on the second driving signal and the third driving signal. The controller 13 can pre-calibrate the relationship between "the applied second driving signal, third driving signal - the amount of pixel movement on the image sensor" and "the amount of pixel movement on the image sensor - the driving amount of the first driving signal", and then the controller 13 can check at least one of the second driving signal and the third driving signal and directly generate the first driving signal.

[0134] As described above, the camera module according to an embodiment of the present disclosure has been described with reference to Figures 11 to 14 Next, the camera module according to an embodiment of the present disclosure and the control operation of the camera module will be described with reference to Figures 15 to 22 The camera module according to an embodiment of the present disclosure and the control operation of the camera module, names, terms, and functions are based on the detailed description of each embodiment and may be the same or different from each other.

[0135] Figure 15 The lens driving device 1000A shown in

[0136] Referring to Figure 15 , the lens driving device 1000A may include a housing 1400, a bobbin 1230 disposed within the housing 1400 and coupled to the lens module, a coil 1320 disposed in the housing 1400, a magnet 1310 disposed in the bobbin 1230, a ball 1600 disposed between the housing 1400 and the bobbin 1230, and a yoke 1340 disposed in the housing 1400. The ball 1600 may also be referred to as a "ball member" or a "ball bearing".

[0137] The lens driving device 1000A may include a cover member 1100 coupled to the housing 1400 to surround the outer surface of the housing 1400. The lens driving device 1000A may include a position sensor 1350 disposed in the housing 1400. Additionally, the lens driving device 1000A may include a circuit board 1330 disposed in the housing 1400, and the position sensor 1350 may be mounted on the circuit board 1330 and electrically connected to the circuit board 1330.

[0138] The bobbin 1230 may have an opening for coupling with the lens module, and the opening of the bobbin 1230 may be in the form of a through hole that penetrates the bobbin in the direction of the optical axis. The magnet 1310 may be disposed on the outer surface of the bobbin 1230. A groove may be formed on the outer surface of the bobbin 1230 for disposing the magnet 1310.

[0139] The coil 1320 may be placed on a side portion 1420 of the housing 1400 opposite to the magnet 1310. For example, a groove for placing the magnet 1310 may be formed on one side of the housing 1400. In another embodiment, the magnet may be placed on the housing, and the coil may be placed on the bobbin.

[0140] The housing 1400 may have an opening 1401 corresponding to the lens module 400, and the opening 1401 of the housing 1400 may be in the form of a through hole that penetrates the housing 1400 in the direction of the optical axis.

[0141] The coil 1320 may be electrically connected to the circuit board 1330.

[0142] The ball 1600 may support the bobbin 1230 to prevent movement relative to the housing 1400. At least a part of the ball 1600 may contact at least a part of the housing 1400 and at least a part of the bobbin 1230, thereby reducing the friction between the housing 1400 and the bobbin 1230.

[0143] The yoke 1340 may be placed 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 placed outside the circuit board 1330, and the coil 1320 may be placed between the yoke 1340 and the magnet 1310.

[0144] The yoke 1340 may be made of a material capable of generating an attractive force between the yoke and the magnet 1310, such as a magnet or metal. Thus, an attractive force may be applied between the yoke 1340 and the magnet 1310 in a direction perpendicular to the optical axis. By this attractive force, the ball 1600 may be kept in contact with the bobbin 1230 and the housing 1400.

[0145] The housing 1400 may be formed with a first receiving groove 1410 for receiving at least a part of the ball 1600 or for placing at least a part of the ball 1600. The bobbin 1230 may be formed with a second receiving groove 1231 for receiving at least another part of the ball 1600 or for placing at least another part of the ball 1600.

[0146] The first receiving groove 1410 may be formed on the inner side or inner surface of at least one corner of the housing 1400, and the second receiving groove 1231 may be formed on the outer side or outer surface of at least one corner of the bobbin 1230. The first receiving groove 1410 and the second receiving groove 1231 may face each other or be opposite to each other, and the ball 1600 may be disposed between the first receiving groove 1410 and the second receiving groove 1231 and may be in contact with each of the first receiving groove 1410 and the second receiving groove 1231. The number of balls 1600 disposed between the first receiving groove 1410 and the second receiving groove 1231 may be one or more.

[0147] In Figure 15 it, the first receiving groove may be formed at each of two corners of the housing 1400 that face each other or are oppositely positioned, and the second receiving groove may be formed at each of two corners of the bobbin 1230 corresponding to the two corners of the housing 1400.

[0148] In another embodiment, the first receiving groove may be formed at each of the four corners of the housing 1400, and the second receiving groove may be formed at each of the four corners of the bobbin 1230 corresponding to the four corners of the housing 140.

[0149] In another embodiment, the first receiving groove may be formed at each of two corners of the housing 1400 adjacent to the side 1420 where the coil 1320 and / or the circuit board 1330 is placed in the housing 1400.

[0150] In addition, the second receiving groove may be formed at each of two corners of the bobbin 1230 corresponding to the two corners of the housing 1400 adjacent to the side 1420 of the housing 1400.

[0151] In another embodiment, the first receiving groove may be formed at each of two corners adjacent to the side opposite to the side 1420 of the housing 1400. The second receiving groove may be formed at each of two corners of the bobbin 1230 corresponding to the two corners adjacent to the side opposite to the side 1420 of the housing 1400.

[0152] As Figure 15As shown, the housing 1400 can be implemented as a single body, but is not limited thereto. In another embodiment, the housing 1400 can include a housing and a base coupled to the housing. In this case, the base can have an opening that is the same as or similar to the opening 1401 of the housing 1400.

[0153] Figure 16 can be a lens driving device 1000B that is a modified embodiment of Figure 15 .

[0154] In Figure 16 , the ball 1600 can be placed between two corners adjacent to the placement coil 1320 and / or the side portion 1420 of the circuit board 1330 of the housing 1400 and the corresponding outer surfaces of the bobbin 1230.

[0155] For example, in Figure 16 , a first receiving groove 1410 can be formed at each of two corners of the housing 1400 adjacent to the placement coil 1320 and / or the side portion 1420 of the circuit board 1330 of the housing 1400, and a second receiving groove 1231 can be formed at the corners of the bobbin 1230 corresponding to the two corners of the housing 1400.

[0156] The magnet 1310A can be placed between the balls 1600 received in the second receiving grooves 1231 formed at two corners of the bobbin 1230. For example, the magnet 1310A can be placed between two second receiving grooves 1231 formed at two corners of the bobbin 1230.

[0157] Figure 17 can be a lens driving device 100C that is a modified embodiment of Figure 15 .

[0158] Figure 15 and Figure 16 The lens driving devices shown are lens driving devices that drive the bobbin 1230 or a lens module provided in the bobbin 1230 in the optical axis direction. Figure 17 The lens driving device shown is a lens driving device that drives the bobbin 1230 or a lens module provided in the bobbin 1230 in the optical axis direction and in a direction perpendicular to the optical axis.

[0159] In Figure 17 , the bobbin 1230 can be placed in a first housing 1450, and the first housing 1450 can be placed in a second housing 1460. The ball 1600 for AF driving can be placed between the first housing 1450 and the second housing 1460. The ball 1600 can support the first housing 1450 to move relative to the second housing 1460. The coil 1320 can be placed outside the second housing 1460.

[0160] The moving member 1510 can be placed between the lower surface of the bobbin 1230 and the first housing 1450. The first ball 1710 can be placed between the lower surface of the bobbin 1230 and the upper surface of the moving member 1510, and the second ball 1720 can be placed between the lower surface of the moving member 1510 and the first housing 1450. The first ball 1710 and the second ball 1720 can support the bobbin 1230 to move relative to the first housing 1450.

[0161] Figure 18 and Figure 19 is a diagram for explaining the closed-loop control of the camera module, Figure 20 is a block diagram of a camera module according to an embodiment of the present disclosure, Figure 21 and Figure 22 is a diagram for explaining the control operation of a camera module according to an embodiment of the present disclosure.

[0162] Referring to Figures 15 to 17 , the circuit board 1330 can correspond to the driving IC, and the position sensor 1350 can correspond to the Hall sensor. The position sensor 1350 can be placed on the circuit board 1330 and electrically connected to the driving IC of the circuit board 1330. The driving IC of the circuit board 1330 can apply a current to the coil 1320.

[0163] The position sensor 1350 can sense the driving 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 the AF driving in which the bobbin 1230 moves in the optical axis direction. Additionally, for example, the position sensor 1350 can sense the position of the bobbin 1230 in the direction perpendicular to the optical axis direction during the OIS driving in which the bobbin 1230 moves in the direction perpendicular to the optical axis direction. In the case of sensing the OIS driving, the position sensor 1350 can be disposed on the circuit board on the lower surface of the bobbin 1230.

[0164] Referring to Figure 18 and Figure 19 , when a control operation is performed to apply a driving signal to the actuator that drives the lens or the image sensor, the sensed signal sensed by the Hall sensor can be fed back relative to the driving signal generated by the AP.

[0165] More specifically, in Figure 19In the first scenario, the driver IC can perform a DAC (Digital-to-Analog Converter) on the actuator. When a driving signal is applied to the actuator to drive it, the Hall sensor in the second scenario can sense the position of the actuator. The Hall sensor can sense the position of the actuator through a sensing cycle consisting of positive-response sensing and negative-response sensing. The Hall sensor can transmit the sensing signal for sensing the position of the actuator to the AMP (Amplifier) of the driver IC. The position sensing signal can be amplified by the AMP and converted into a digital signal by an ADC (Analog-to-Digital Converter).

[0166] Then, the position signal sensed by the Hall sensor can be fed back to the driving signal applied to the driver IC from the AP (Application Processor). The signal fed back from the third scenario can be controlled by a PID (Proportional-Integral-Derivative) and converted into a current applied to the coil by a DAC (Digital-to-Analog Converter).

[0167] The camera module according to this embodiment may include an actuator 211, a position sensor 212, a driving unit 213, and a controller 214.

[0168] The actuator 211 can drive at least one of a lens or an image sensor. The actuator 211 can drive a lens or an 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 (Auto Focus) driving. The actuator 211 can be an actuator for OIS (Optical Image Stabilization) driving. The actuator 211 can be a spring-type driving actuator. The actuator 211 can be a ball-type driving actuator. The actuator 211 includes a housing and a bobbin disposed in the housing, and can drive the bobbin.

[0169] The position sensor 212 can sense the position of the actuator 211. The position sensor 212 can sense the position of the bobbin. The position sensor 212 can be a Hall sensor. The position sensor 212 can sense the position of the actuator 211 for AF feedback driving and OIS feedback driving. The position sensor 212 can correspond to, face, or overlap with a sensing magnet disposed in the actuator 211. The position sensor 212 can output a sensing signal to the controller 214 according to the result of detecting the magnetic field strength of the sensing magnet based on the movement of the bobbin. The position sensor 212 can output a sensing signal to the driving unit 213 according to the result of detecting the magnetic field strength of the sensing magnet based on the movement of the bobbin. The position sensor 212 can be placed on the actuator 211, and the sensing magnet can be placed on the housing where the actuator 211 is placed.

[0170] The driving unit 213 may drive the actuator 211 based on a driving signal. The driving unit 213 may be a driver IC. The driving unit 213 may be a driver IC including a position sensor 212. The driving unit 213 may receive a position sensing signal sensed by the position sensor 212. The driving unit 213 may feedback the position sensing signal sensed by the position sensor 212 to the driving signal generated by the controller 214 and apply it to the actuator 211. The driving unit 213 may apply the driving signal generated by the controller 214 to the actuator 211. At this time, the driving signal may be a signal in which the sensing signal sensed by the position sensor 212 is reflected as a feedback signal.

[0171] As described above, the driving unit 213 may perform AMP (amplifier) for amplifying the sensing signal sensed by the position sensor 212, ADC (analog-to-digital converter) for converting an analog signal into a digital signal, DAC (digital-to-analog converter) for converting a digital signal into an analog signal, and PID control. The driving unit 213 may have the same configuration as the controller 214 described below, or the driving unit 213 may have a configuration independent of the controller 214.

[0172] The controller 214 may generate a driving signal based on the position information sensed by the position sensor 212. After applying the first driving signal according to the first sensing period, when applying the second driving signal according to the second sensing period, the controller 214 may gradually increase or decrease the level of the second driving signal. Here, the sensing period may refer to an operation period including generating a driving signal for position control and applying the driving signal to the actuator 211 after positive response sensing and negative response sensing by the position sensor 212. The first sensing period and the second sensing period may have the same time interval. The second sensing period may be temporally continuous with respect to the first sensing period. During the first sensing period, the first driving signal applied to the coil does not change. During the second sensing period, the driving signal applied to the coil may change at least twice. The levels of at least two driving signals applied to the coil during the second sensing period may be different.

[0173] Referring to Figure 21 (a) of, in the driving control of the existing actuator, the level of the driving current is applied as A according to the first driving signal D1, and when the second driving signal D2 is applied, the level of the driving current immediately increases from A to B. Thereafter, the level of the driving current remains B until the third driving signal D3 according to the sensing period is applied. According to the existing actuator driving control method, since the change amount of the driving current level is large, driving noise is generated due to the movement of the ball in the spherical driving actuator. Therefore, in order to reduce the driving noise of the actuator, the camera module according to the present embodiment drives the actuator by slightly increasing and decreasing the level of the driving current.

[0174] Specifically, referring to Figure 21 (b) of, the controller 214 according to the present embodiment can gradually increase the drive current level of the second drive signal D2 while the drive current level according to the first drive signal D1 is A. The controller 214 can gradually increase the level of the drive current until the third drive signal D3 is applied, so as to apply the drive current level B according to the second drive signal D2.

[0175] The controller 214 can gradually increase the drive current levels M1 and M2 that are greater than A and less than B, so that when the drive current level is applied as A, the drive current level B is applied according to the second drive signal D2. Then, when the third drive signal D3 is applied in the case where the level of the drive current according to the second drive signal D2 is applied as B, the controller 214 can gradually increase and decrease the drive current level according to the third drive signal D3.

[0176] Since, according to the first drive signal D1, the level of the drive current is applied to the actuator 211 as A, the magnitude of the first drive signal D1 can be regarded as A. Since, according to the second drive signal D2, the level of the drive current is applied to the actuator 211 as B, the magnitude of the second drive signal D2 can be regarded as B. The level of the drive current can be replaced by the drive code applied to the actuator 211. The drive code can mean that the level of the drive current is encoded. When the magnitude of the level of the drive current increases, the driving amount of the actuator 211 can increase. When the magnitude of the drive code increases, the driving amount of the actuator 211 can increase.

[0177] The number of steps of the level of the second drive signal applied during the second sensing period can vary according to 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 can 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 can decrease.

[0178] Referring to Figure 22 , the time t from applying the first drive signal D1 until applying the second drive signal D2 and the time t from applying the second drive signal D2 until applying the third drive signal D3 can be the same. The level difference of the number of steps N can vary according to the absolute value of the difference between the level A of the signal according to the first drive signal D1 and the level B of the signal according to the second drive signal D2.

[0179] For example, when the absolute value of the level difference between the first driving signal and the second driving signal is a first value, the controller 214 can increase or decrease the driving signal in N steps. When the absolute value of the level difference between the first driving signal and the second driving signal is a second value, the controller 214 can increase or decrease the driving signal in M steps. Here, when the first value is greater than the second value, N can be greater than M.

[0180] According to the difference between the level A of the first driving signal and the level B of the second driving signal, the signal level difference of the steps applied from the first driving signal to the second driving signal can vary. As the level A of the first driving signal and the level B of the second driving signal increase, the signal level difference of each step applied from the first driving signal to the second driving signal can increase. As the magnitude A of the first driving signal and the level B of the second driving signal decrease, the signal level difference of each step applied from the first driving signal to the second driving signal can decrease.

[0181] Refer to Figure 22 , the level difference X of the signal that increases and decreases step by step can vary according to the absolute value of the difference between the level A of the signal according to the first driving signal D1 and the level B of the signal according to the second driving signal D2.

[0182] For example, when the absolute value of the level difference between the first driving signal and the second driving signal is a first value, the controller 214 can increase or decrease the driving signal to a step with a level difference of X. When the absolute value of the level difference between the first driving signal and the second driving signal is a second value, the controller 214 can increase or decrease the driving signal to a step with a level difference of Y. Here, when the first value is greater than the second value, X can be greater than Y.

[0183] The controller 214 can control the number of steps or the level of the signal that increases and decreases step by step by considering the difference in the current level of the driving signal. Whenever a driving signal according to the sensing period is applied, the controller 214 can control the number of steps of fine control or the level of the signal that increases and decreases step by step. Thus, the actuator operation for noise reduction can be optimized according to the difference in the level of the driving signal applied to the actuator.

[0184] 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. In addition, the features, structures, effects, etc. illustrated in each embodiment can be combined, modified, and implemented by those of ordinary skill in the art to which the embodiments belong in other embodiments. Therefore, the content related to these combinations and modifications should be interpreted as being included within the scope of the embodiments.

Claims

1. A light-emitting device driving module, comprising: A first switching device, connecting the light-emitting device and a driving power source; A second switching device, connecting the light-emitting device and a grounding portion; A third switching device, connecting the light-emitting device and a storage capacitor; And A controller, controlling the operations of the first switching device to the third switching device, wherein the light-emitting device is charged through the driving power source and the storage capacitor, and is discharged through the grounding portion and the storage capacitor.

2. The light-emitting device driving module according to claim 1, further comprising: An inductor, the inductor being disposed between the light-emitting device and the third switching device.

3. The light-emitting device driving module according to claim 2, further comprising: A fourth switching device, the fourth switching device connecting the light-emitting device and the storage capacitor and being connected in parallel with the third switching device.

4. The light-emitting device driving module according to claim 1, Among them, when performing an operation of the light-emitting device for light emission, the controller turns on and off the third switching device before turning on the first switching device, and turns on and off the third switching device after turning off the first switching device.

5. The light-emitting device driving module according to claim 1, Among them, if a second voltage or a higher voltage is applied to the light-emitting device, the light-emitting device operates to emit light, wherein, during an initial operation for light emission of the light-emitting device, the controller turns on the third switching device until a first voltage is applied to the light-emitting device, and wherein the second voltage is greater than the first voltage.

6. The light-emitting device driving module according to claim 4, Among them, the controller turns off the first switching device to extinguish the light-emitting device, and then turns on the third switching device.

7. The light-emitting device driving module according to claim 1, Among them, during an initial operation for light emission of the light-emitting device, the controller turns on the third switching device for a first time, turns on the first switching device for a second time after the first time, turns on the third switching device for a third time after the second time, and turns on the second switching device after the third time.

8. The light-emitting device driving module according to claim 7, Among them, the light-emitting device includes a plurality of light-emitting devices, wherein the controller increases the first time for turning on the third switching device as the number of the plurality of light-emitting devices increases.

9. The light-emitting device driving module according to claim 1, Among them, the light-emitting device includes a parasitic capacitor, and wherein the capacitance of the storage capacitor is more than 10 times the capacitance of the parasitic capacitor.

10. A light-emitting device driving module, comprising: A first switching device, connecting the light-emitting device and a driving power source; A second switching device, connecting the light-emitting device and a grounding portion; A third switching device, connecting the light-emitting device and a storage capacitor; And A controller, controlling the operations of the first switching device to the third switching device, Wherein, the controller turns on the third switching device before turning on the first switching device to charge the energy of the storage capacitor to the light-emitting device.

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