Lens driving system and portable device

Abstract

A lens driving system controls a relative position of a lens with respect to an image sensor, the lens driving system including a plurality of lens driving devices corresponding to a plurality of lenses, the plurality of lens driving devices controlling the relative position of each corresponding lens, each image sensor outputting detection data, and a control unit controlling which of the detection data of the image sensors is used to generate image data based on state information of the camera device, and a signal processing unit of at least one of the lens driving devices changing power consumption of a position detection unit based on the state information. A portable device is also provided.

Description

Technical Field

[0001] This invention relates to a lens driving system and a portable device. Background Technology

[0002] Patent document 1 discloses a method for controlling multiple cameras mounted on a portable device.

[0003] [Existing technical documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] U.S. Application Publication No. 2022 / 0182546 Summary of the Invention

[0006] In a first embodiment of the present invention, a lens driving system is provided, which controls the relative position of a lens with respect to multiple image sensors disposed corresponding to multiple lenses in a camera device. The lens driving system may include multiple lens driving devices disposed corresponding to the multiple lenses, each controlling the relative position of its corresponding lens. In any lens driving system, each lens driving device may have a position detection unit that detects the current relative position of the corresponding lens. In any lens driving system, each lens driving device may have a calculation unit that calculates a driving amount for at least one of the lens and the image sensor based on the output of the position detection unit (i.e., a current position signal) and an input target position signal. In any lens driving system, each lens driving device may have a driving unit that drives at least one of the lens and the image sensor based on the driving amount. In any lens driving system, each lens driving device may have a signal processing unit that outputs a power control signal to control the power consumption of the position detection unit. In any of the lens driving systems, each image sensor can output detection data, and based on the state information of the camera device, control is made to determine which image sensor's detection data is used to generate image data. In any of the lens driving systems, the signal processing unit of at least one of the lens driving devices can change the power consumption of the position detection unit based on the state information of the camera device. At this time, the communication path of the lens driving device can be active.

[0007] In any of the lens driving systems, the signal processing unit can, based on the state information, ensure that the power consumption of the corresponding position detection unit is less than that of the other position detection units. At this time, the driving unit can be activated to generate image data.

[0008] In any of the lens driving systems, the power consumption of the corresponding driving unit can be maintained such that the power consumption of the corresponding position detection unit is less than that of the other position detection units, even if the signal processing unit does so. In this case, image stabilization can be performed by controlling the lens position through the driving device, thereby generating image data using the image sensor.

[0009] In any of the lens driving systems, the power consumption of the corresponding driving unit can be reduced if the power consumption of the corresponding position detection unit is less than that of the other position detection units in the signal processing unit. At this time, image shakiness correction can be performed by controlling the lens position through the driving device, thereby generating image data using the image sensor.

[0010] In any of the lens driving systems, the signal processing unit can reduce the power consumption of the position detection unit by reducing the total time that the position detection unit operates to output the current position signal per unit time.

[0011] In any of the lens driving systems, the signal processing unit can reduce the power consumption of the position detection unit by increasing the idle period during which the position detection unit does not perform the action of outputting the current position signal per unit time.

[0012] In any of the lens driving systems, the signal processing unit can reduce the power consumption of the position detection unit by shortening the switching period during which the position detection unit operates to output the current position signal once.

[0013] In any of the lens driving systems, the plurality of lens driving devices may include a first lens driving device and a second lens driving device for controlling the relative position of the shared lenses. In any of the lens driving systems, based on the status information, the power consumption of either the first lens driving device or the second lens driving device may be controlled to be less than the power consumption of the other.

[0014] In any of the lens driving systems, the position detection unit can perform continuous and intermittent operations. In the continuous operation, the transition period for outputting the current position signal is continuous, while in the intermittent operation, the idle period (not for outputting the current position signal) and the transition period are repeated. In any of the lens driving systems, the signal processing unit can reduce power consumption by enabling the position detection unit to perform the intermittent operation.

[0015] In any of the lens driving systems, the repetition period obtained by adding the transition period of one of the intermittent actions to the idle period of one of the intermittent actions may be less than the period during which the current position signal is output once in the continuous actions.

[0016] In any of the lens driving systems, the signal processing unit can adjust at least one of the transition period and the idle period so that the repetition frequency of the transition period and the idle period in the intermittent operation is above a preset set frequency.

[0017] In any of the lens driving systems, the set frequency can be above the upper limit of the audible frequency range.

[0018] In any of the lens driving systems, the set frequency can be 10 kHz or higher.

[0019] In any of the lens driving systems, the position detection unit may include a position sensor for detecting the relative position. In any of the lens driving systems, the position detection unit may include an analog-to-digital (AD) converter that converts the relative position into digital data. In any of the lens driving systems, the signal processing unit may reduce the oversampling ratio of the AD converter compared to continuous operation when the position detection unit performs the intermittent operation, thereby increasing the output rate. Alternatively, the oversampling ratio of the AD converter may be reduced, but the output rate may be maintained by setting the idle period of the AD converter.

[0020] In any of the lens driving systems, when the signal processing unit causes the position detection unit to perform the intermittent operation, compared to the case of continuous operation, the resolution of the AD converter can be reduced to increase the output rate. Alternatively, the oversampling ratio of the AD converter can be reduced, but the output rate can be maintained by setting the idle period of the AD converter.

[0021] In any of the lens driving systems, the position detection unit may include a position sensor that detects the relative position and outputs a differential detection signal. In any of the lens driving systems, the position detection unit may include a chopper modulator that modulates the polarity of the differential detection signal according to a chopper frequency. In any of the lens driving systems, the position detection unit may include a differential amplifier that amplifies and outputs the output of the chopper modulator. In any of the lens driving systems, the position detection unit may include a chopper demodulator that demodulates the output of the differential amplifier according to the chopper frequency. In any of the lens driving systems, the position detection unit may include an AD converter that converts the detection signal output by the chopper demodulator into digital data. In any of the lens driving systems, the signal processing unit may control the output rate of the AD converter, thereby controlling the power consumption of the position detection unit. In any of the lens driving systems, the change in the chopper frequency before and after the change in the output rate of the AD converter may be less than the change in the output rate.

[0022] In any of the lens driving systems, the chopping frequency may remain constant before and after the output rate of the AD converter changes.

[0023] In any of the lens driving systems, the repetition frequency of the transition period and the idle period during the intermittent operation can be greater than or equal to the calculation frequency at which the calculation unit calculates the lens driving amount.

[0024] In any of the lens driving systems, the position detection unit may have a high-speed intermittent mode in which the repetition frequency during the transition period and the idle period is above an audible frequency, and a low-speed intermittent mode below the audible frequency. In any of the lens driving systems, the signal processing unit may switch between the high-speed intermittent mode and the low-speed intermittent mode based on an external signal.

[0025] In a second embodiment of the present invention, a portable device equipped with a camera is provided. In the portable device, the camera device may include multiple image sensors. In any of the portable devices, the camera device may include multiple lenses disposed corresponding to the multiple image sensors. In any of the portable devices, the camera device may include a lens driving system for controlling the relative position of the lenses relative to the image sensors. In any of the portable devices, the lens driving system may include multiple lens driving devices, which are disposed corresponding to the multiple lenses and control the relative position of their respective lenses. In any of the portable devices, each lens driving device may have a position detection unit that detects the current relative position of the corresponding lens. In any of the portable devices, each lens driving device may have a calculation unit that calculates a driving amount for at least one of the lenses and the image sensors based on the output of the position detection unit (i.e., the current position signal) and an input target position signal. In any of the portable devices, each lens driving device may have a driving unit that drives at least one of the lenses and the image sensors based on the driving amount. In any of the portable devices, each lens driving device may have a signal processing unit that outputs a power control signal to control the power consumption of the position detection unit. In any of the portable devices, each image sensor may output detection data, and based on the status information of the camera device, control which image sensor's detection data is used to generate image data. In any of the portable devices, the signal processing unit of at least one of the lens driving devices may change the power consumption of the position detection unit based on the status information.

[0026] The portable device may include a central control unit, which controls each of the signal processing units based on the status information.

[0027] Furthermore, the description of the invention does not list all the features of the invention. Additionally, sub-combinations of these feature groups can also constitute an invention. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating a structural example of a portable device 200 according to an embodiment of the present invention.

[0029] Figure 2 This is a diagram illustrating an example of the structure of a camera device 100.

[0030] Figure 3 This is a diagram illustrating a structural example of the lens drive device 120.

[0031] Figure 4This is a diagram illustrating an example of the operation of the position detection unit 130.

[0032] Figure 5 This is a diagram illustrating another example of the operation of the position detection unit 130.

[0033] Figure 6 This is a diagram illustrating another example of the operation of the position detection unit 130.

[0034] Figure 7 This is a diagram illustrating a control example of the position detection unit 130.

[0035] Figure 8 This is a diagram showing another structural example of the position detection unit 130.

[0036] Figure 9 This is a diagram illustrating a structural example of the chopper modulator 133, amplifier 134, and chopper demodulator 135.

[0037] Figure 10 This is a diagram showing an example of the time waveform and spectrum of a differential signal (Vampout, -Vampout).

[0038] Figure 11 This is a diagram showing an example of the time waveform and spectrum of the detection signal (Vout, -Vout).

[0039] Figure 12 This is a graph showing the frequency characteristics and chopping frequency of the AD converter 136 when the output rate is high or low.

[0040] Figure 13 This is a diagram showing another structural example of the camera module 110.

[0041] Explanation of icon numbers

[0042] 100: Camera device

[0043] 102: Lens

[0044] 104: Driven element

[0045] 106: Driving element

[0046] 108: Image Sensor

[0047] 110: Camera Module

[0048] 120: Lens drive device

[0049] 122: Signal Processing Department

[0050] 124: Calculation Department

[0051] 126: Drive Unit

[0052] 130: Position Detection Department

[0053] 132: Position sensor

[0054] 133: Chopper modulator

[0055] 134: Amplifier

[0056] 135: Chopper demodulator

[0057] 136: AD converter

[0058] 150: Lens Drive System

[0059] 200: Portable devices

[0060] 202: Central Control Department

[0061] 204: Display device

[0062] 206: Communication device

[0063] 208: Storage device

[0064] 210: Communication Path Detailed Implementation

[0065] The present invention will now be described through embodiments thereof, but these embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of the features described in the embodiments are necessary for the solutions provided by the invention.

[0066] Figure 1 This diagram illustrates a structural example of a portable device 200 according to an embodiment of the present invention. The portable device 200 is equipped with a camera device 100. The portable device 200 may be a camera device or a terminal such as a mobile phone. In this example, the portable device 200 may also include at least one of a central control unit 202, a display device 204, a communication device 206, a communication path 210, and a storage device 208.

[0067] The central control unit 202 controls the various structures of the portable device 200, such as the camera device 100. The central control unit 202 is, for example, a processor such as a central processing unit (CPU). The central control unit 202 communicates with the various structures of the portable device 200 via communication path 210, for example, through serial communication, parallel communication, network, or wireless communication. The signals transmitted by the central control unit 202 may also be via an Inter-Integrated Circuit (I2C) bus.

[0068] Display device 204 displays images. Display device 204 can display images captured by camera device 100, or other images. Communication device 206 communicates with external devices of portable device 200 wirelessly or otherwise. Communication device 206 can perform voice communication or data communication including data other than voice. Storage device 208 stores information. Storage device 208 can store image data output by camera device 100, or other data.

[0069] Camera device 100 captures images and generates image data. Camera device 100 may have multiple camera modules. Each camera module may have a lens and an image sensor. For example, camera device 100 may switch the camera module used to generate image data according to the magnification.

[0070] Figure 2 This is a diagram illustrating a structural example of a camera device 100. The camera device 100 in this example includes multiple camera modules 110. Figure 2 The example shows two camera modules 110-1 and 110-2, but the camera device 100 may also include more camera modules 110.

[0071] Each camera module 110 includes a lens drive unit 120, a lens 102, and an image sensor 108. In this specification, the multiple lens drive units 120 disposed in the multiple camera modules 110 are collectively referred to as the lens drive system 150. The lens drive system 150 controls the relative position of the image sensors 108 and the lenses 102, which are disposed in the camera device 100 corresponding to the multiple image sensors 108. The multiple lens drive units 120 are disposed corresponding to the multiple lenses 102 and drive the relative position of their respective lenses 102.

[0072] Lens 102 focuses light from the subject onto image sensor 108. Image sensor 108 outputs detection data corresponding to the intensity of the received light. Image sensor 108 may have multiple light-receiving elements arranged in a two-dimensional array. Each light-receiving element outputs an electrical signal corresponding to the intensity of the received light. By combining these electrical signals, detection data representing a two-dimensional image is generated. Image sensor 108 may be, for example, a complementary metal-oxide-semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor, but is not limited thereto.

[0073] Image data is generated based on the detection data output by each image sensor 108. The generated image data can be displayed on the display device 204 as described above, or it can be stored in the storage device 208. The camera device 100 controls which image sensor 108's detection data is used to generate image data based on the camera device 100's status information.

[0074] Status information includes information such as camera magnification and camera mode specified by the user. Camera modes may include, for example, a standard camera mode with different viewing angles and a wide-angle camera mode. The lens 102 and camera module 110 to be used are determined based on the camera magnification or camera mode. The camera device 100 can use the detection data from the image sensor 108 in the camera module 110 corresponding to the status information as image data. The camera device 100 can combine multiple detection data from two or more camera modules 110 to generate image data. The camera device 100 may also include a data selection unit that selects detection data based on the status information. In another example, the central control unit 202 may function as a data selection unit via the communication path 210.

[0075] The lens drive device 120 controls the relative position of the lens 102. In each example, the lens drive device 120 controls the relative position between the lens 102 and the image sensor 108 by moving the lens 102. However, the lens drive device 120 may move the image sensor 108, or both the lens 102 and the image sensor 108. In this specification, the relative position of the lens 102 with respect to the image sensor 108 is sometimes simply referred to as the lens position or the lens location.

[0076] The lens drive device 120 can control the focal position of the lens by controlling the position of the lens in a direction parallel to the lens optical axis, and can also control the position of the imaging range by controlling the position of the lens in a direction perpendicular to the lens optical axis. The lens drive device 120 can control the position of the lens 102 according to the operation of the user or others, and can also automatically control the position of the lens 102, such as autofocus or image stabilization.

[0077] The camera module 110 in this example also includes a driving element 106 and a driven element 104. The driving element 106 moves the lens 102 according to control from the lens driving device 120. The driving element 106 can be provided in each direction that moves the lens 102. In this example, the driving element 106 is a coil or other element that generates a magnetic field, but it is not limited to this. The lens driving device 120 can provide one for multiple driving elements 106, or it can provide one for each driving element 106.

[0078] The driven element 104 is fixed to the lens 102 directly or indirectly via other components. The driven element 104 moves together with the lens 102 using the magnetic field generated by the driving element 106, etc. In this example, the driven element 104 is, for example, a magnet, but is not limited to this. When the image sensor 108 is moved, the driven element 104 is fixed to the image sensor 108.

[0079] As described above, detection data for generating image data is selected based on the status information of the camera device 100. On the other hand, for example, when the camera magnification is changed sequentially, the detection data to be selected may sometimes be switched according to the camera magnification. Even in this case, in order to continuously generate image data, camera modules other than the currently selected camera module 110 are operated to generate detection data.

[0080] However, if multiple camera modules 110 operate simultaneously, power consumption increases. In this example, the lens drive system 150 changes the power consumption of at least one lens drive device 120 based on the status information of the camera device 100. For example, it makes the power consumption of the lens drive device 120 in a camera module 110 other than the currently selected camera module 110 less than the power consumption of other lens drive devices 120. This reduces the power consumption of the lens drive system 150. At this time, the communication path 210 between the central control unit 202 and each lens drive device 120 remains active. "Active state" or "activated" refers to a state where at least one of sending and receiving information based on the communication path 210 can be performed. For example, the state in which communication is established between the central control unit 202 and the lens drive device 120 via the communication path 210 can be set as active.

[0081] Figure 3 This diagram illustrates a structural example of the lens driving device 120. The lens driving device 120 includes a position detection unit 130, a signal processing unit 122, a calculation unit 124, and a driving unit 126. The position detection unit 130, signal processing unit 122, calculation unit 124, and driving unit 126 can be integrated into a single integrated circuit (IC) chip. The position detection unit 130 detects the current position of the corresponding lens 102 and outputs a current position signal CP. The corresponding lens 102 refers to the lens 102 that is controlled by the lens driving device 120. The position detection unit 130 detects the position of the lens 102 by detecting the magnetic field from a magnet disposed on the lens 102.

[0082] The signal processing unit 122 outputs a target position signal TP, indicating the target position of the lens 102. The target position can be determined by the user's operation, or it can be automatically calculated by the signal processing unit 122 or the central control unit 202 through functions such as autofocus or image stabilization. The target position can be input from the central control unit 202 or the like to the signal processing unit 122 via the communication path 210.

[0083] The calculation unit 124 calculates the driving amount of the lens 102 based on the input current position signal CP and target position signal TP. The calculation unit 124 can calculate the driving amount representing the direction and magnitude of the lens 102's movement based on the difference between the current position and the target position of the lens 102. As an example, the calculation unit 124 can also perform proportional-integral-differential (PID) calculations. The calculation unit 124 can also use proportional gain, integral gain, and derivative gain as control parameters.

[0084] The drive unit 126 drives the lens 102 based on the drive quantity input from the calculation unit 124. In this example, the drive unit 126 controls each drive element 106 according to the drive quantity. For example, the drive unit 126 controls the magnetic field generated by the drive element 106 by controlling the current or voltage applied to each drive element 106, thereby driving the lens 102.

[0085] The signal processing unit 122 outputs a power control signal PC to control the power consumption of the position detection unit 130. The signal processing unit 122 of at least one lens driving device 120 changes the power consumption of the position detection unit 130 based on the status information of the camera device 100. The signal processing unit 122 can also, based on the status information of the camera device 100, make the power consumption of a corresponding position detection unit 130 less than the power consumption of other position detection units 130. For example, the power consumption of the position detection unit 130 of the camera module 110 that is not used to generate image data can be controlled to be less than the power consumption of the position detection unit 130 of the camera module 110 that is used to generate image data. Through this control, the power consumption of the camera device 100 can be reduced. The central control unit 202 can generate the power control signal PC based on the status information and send it to each signal processing unit 122 via the communication path 210. In another example, the central control unit 202 can send the status information to the signal processing unit 122 via the communication path 210, and the signal processing unit 122 generates the power control signal PC based on the status information.

[0086] The signal processing unit 122 can reduce the power consumption of the position detection unit 130 by controlling its operation period. The operation period of the position detection unit 130 refers to the period during which it operates to generate the current position signal CP. The operation period of the position detection unit 130 can also refer to the period during which drive power is supplied to the position detection unit 130. The signal processing unit 122 can reduce the power consumption of the position detection unit 130 by decreasing the output frequency or update frequency of the current position signal CP in the position detection unit 130. At this time, the communication path 210 of the lens drive device 120 corresponding to the position detection unit 130 with reduced power consumption can be activated. Furthermore, the drive unit 126 corresponding to the position detection unit 130 with reduced power consumption can be operated to a state capable of generating image data. Additionally, the drive unit 126 can be operated to perform hand-eye correction.

[0087] When the signal processing unit 122 makes the power consumption of the corresponding position detection unit 130 less than the power consumption of other position detection units 130, the power consumption of the corresponding drive unit 126 can be maintained. That is, the drive unit 126 can be continuously supplied with power for controlling the position of the lens 102.

[0088] For example, even during the period when the position detection unit 130 has not detected a new relative position of the lens 102 and the current position signal CP has not been updated, the calculation unit 124 and the drive unit 126 control the position of the lens 102 based on the previous current position signal CP. In this case, power is supplied to the drive element 106 for generating a magnetic field, etc. Therefore, although a slight control error occurs due to the reduced detection frequency of the current position, the position of the lens 102 can be maintained approximately correctly. Therefore, even when the camera module 110 used to generate image data is switched to the camera module 110, there is no need to significantly move the position of the lens 102, and appropriate image data can be generated without delay. Therefore, appropriate image data can be generated while reducing the power consumption of the camera device 100. In another example, the signal processing unit 122 can reduce the power consumption of the corresponding drive unit 126 when the power consumption of the corresponding position detection unit 130 is less than that of other position detection units 130. Therefore, power consumption can be further reduced.

[0089] In this example, the position detection unit 130 includes a position sensor 132, an amplifier 134, and an AD converter 136. The position sensor 132 detects the lens position of the lens 102. The position sensor 132 is, for example, a silicon Hall element, a compound Hall element, or a magnetoresistive element.

[0090] Amplifier 134 amplifies and outputs the lens position signal from position sensor 132. Amplifier 134 can be a buffer with a 1x amplification ratio. Amplifier-to-digital converter 136 converts the lens position signal detected by position sensor 132 into digital data. Amplifier-to-digital converter 136 outputs the current position signal CP after converting the lens position signal into digital data.

[0091] The signal processing unit 122 can control the power consumption of at least one of the position sensor 132, amplifier 134, and AD converter 136 based on the status information of the camera device 100. The signal processing unit 122 can control the power consumption of the position sensor 132 based on the status information of the camera device 100. For example, the signal processing unit 122 controls the frequency at which the position sensor 132 outputs or updates a signal indicating the lens position. The signal processing unit 122 can supply power to the position sensor 132 at the time when the position sensor 132 should output a signal indicating the lens position. The signal processing unit 122 can control the period during which power is supplied to the position sensor 132 for position detection. The AD converter 136 can operate each time the position sensor 132 outputs a signal indicating the lens position and converts the signal into digital data.

[0092] The signal processing unit 122 can also control the power consumption of the AD converter 136 based on the status information of the camera device 100. The power consumption of the AD converter 136 can be controlled by adjusting the length of the period during which the AD converter 136 operates for AD conversion. Even when the operation period of the AD converter 136 is shortened, the period during which the position sensor 132 detects the lens position can be maintained, and the operation period of the AD converter 136 can also be shortened in the same way.

[0093] Figure 4 This is a diagram illustrating an example of the operation of the position detection unit 130. Figure 4 The diagram illustrates two operating modes with different power consumption. The first operating mode consumes more power than the second. In each operating mode, the position detection unit 130 sequentially outputs multiple current position signals CP. Figure 4 In the process, the outputs of the AD converter 136 [k (where k is n, n+1, n+2, ..., ... The current position signal CP is represented by []. Whenever the value of k in each output increases, the current position signal CP is updated based on the lens position detected by the position sensor 132.

[0094] exist Figure 4In this context, the period represented by the output [k] of the AD converter 136 is the conversion period during which the AD converter 136 operates to generate the current position signal CP. For example, period T1 in the first operating mode and period T3 in the second operating mode are conversion periods. During the conversion period, at least a portion of the AD converter 136 operates according to an operating clock. For example, the AD converter 136 may perform at least any one of the following actions during the conversion period: a sampling action that samples the amplitude value of the input analog signal, a quantization action that generates a discrete value based on the sampling result, and an encoding action that converts the discrete value into a binary digital signal and outputs it.

[0095] exist Figure 4 In this context, the idle period is the period during which the AD converter 136 does not operate to generate the current position signal CP. For example, period T4 in the second operating mode is an idle period. During the idle period, for example, the AD converter 136 may not perform any of the sampling, quantization, and encoding operations. The conversion period can also be the period during which the AD converter 136 converts the current position signal CP corresponding to the lens position into a digital value. The idle period can also be the period during which the AD converter 136 does not output the current position signal CP corresponding to the lens position. During the idle period, the output of the AD converter 136 may maintain the value of the previous current position signal CP or may be a constant value (e.g., 0). During the idle period, the position sensor 132 may or may not detect the lens position.

[0096] In this example, the signal processing unit 122 reduces the power consumption of the position detection unit 130 by reducing the total time that the position detection unit 130 operates to convert the current position signal CP per unit time. Figure 4 In this example, the position detection unit 130 operates during the transition period T1 to generate a current position signal CP. In this example, the position detection unit 130 continuously transitions between each current position signal CP in the first operating mode. Therefore, in the first operating mode, the total operating time of the position detection unit 130 within a unit time (e.g., 2×T1) is 2×T1.

[0097] On the other hand, in the second operating mode, the position detection unit 130 operates for a portion of the transition period T3 within the same unit time (2×T1) to output a current position signal CP, and is idle during the remaining idle period T4. Therefore, in the second operating mode, the total operating time of the position detection unit 130 within the unit time is T3, which is less than the total time of 2×T1 in the first operating mode.

[0098] This processing allows for control of the power consumption of the position detection unit 130. Furthermore, the signal processing unit 122 can reduce the power consumption of the position detection unit 130 by increasing the idle period within a unit of time during which the position detection unit 130 is not operating to output the current position signal CP. Figure 4 In the example, the idle period (2×T1) per unit time in the first action mode is 0, but the idle period (T4) per unit time in the second action mode is 4. The idle period in the first action mode may not be 0. The idle period T4 per unit time in the second action mode may be more than half of the unit time (2×T1).

[0099] exist Figure 4 The diagram illustrates a continuous operation mode as the first operation mode and an intermittent operation mode as the second operation mode. In the continuous operation mode, the conversion periods T1 of multiple current position signals CP are continuous. That is, in the continuous operation mode, there is no idle period between the conversion periods T1 of two current position signals CP. For example, when the position detection unit 130, such as the AD converter 136, operates according to the cycle of the operation clock, the idle period can be longer than one cycle of the operation clock. In the continuous operation mode, there is no idle period longer than one cycle of the operation clock between two conversion periods T1. In the continuous operation mode, sampling, quantization, and encoding operations of the two current position signals CP can be performed continuously without interruption of idle periods.

[0100] In the intermittent operation mode, the position detection unit 130 alternately repeats the transition period T3 and the idle period T4. The idle period T4 is longer than one cycle of the operation clock. The length of the idle period T4 can be more than 25% of the length of the transition period T3, or more than 50%. Figure 4 In this example, the signal processing unit 122 reduces power consumption by causing the position detection unit 130 to operate intermittently.

[0101] Figure 5 This diagram illustrates another example of the operation of the position detection unit 130. The operation of the position detection unit 130 in the first operation mode is similar to... Figure 4 The example is the same. In the second operating mode, the signal processing unit 122 reduces the power consumption of the position detection unit 130 by shortening the transition period T3 during which the position detection unit 130 operates to output a current position signal CP once.

[0102] In this example, the position detection unit 130 in the second operation mode also performs intermittent operation by alternating between the transition period T3 and the idle period T4. The repetition period T2, obtained by adding one transition period T3 and one idle period T4 in the intermittent operation, can be less than or equal to the transition period T1 during which the current position signal is output once in the continuous operation. The repetition period T2 can be the same as the transition period T1. In this case, the period for updating the current position signal CP is the same in both the continuous operation mode and the intermittent operation mode. The transition period T3 can be less than half of the transition period T1. The repetition period T2 can be shorter than the transition period T1. The repetition period T2 can also be less than half of the transition period T1.

[0103] In intermittent operation mode, the frequencies of the repeated transition period T3 and the idle period T4 are set as the repetition frequency. The repetition frequency is the reciprocal of the repetition period (e.g., T2). In continuous operation mode, the reciprocal of the transition period T1 is set as the repetition frequency. Figure 4 In the example shown, the repetition frequency in the intermittent operation mode is lower than the repetition frequency in the continuous operation mode. Since the repetition frequency corresponds to the control frequency of the lens 102, when the repetition frequency decreases, the control frequency of the lens 102 also decreases. When the control frequency of the lens 102 decreases, the user may sometimes hear the control tone of the lens 102. From the viewpoint of the calculation unit 124, the position detection unit 130 operates based on the repetition frequency in a state where it alternately inputs a signal corresponding to the detected actual position information of the lens 102 (called the actual signal) and a signal corresponding to the state where the position detection unit 130 stops operating (called the pseudo signal). From the viewpoint of the entire system, this state can be considered equivalent to the operation of the calculation unit 124 or the drive unit 126 to eliminate the difference between the actual signal and the pseudo signal. Moreover, this operation is the main reason for the generation of the control tone of the lens 102. Therefore, by controlling the frequency band of the repetition frequency, it is also possible to control the generation frequency band of the control tone from the actual signal and the pseudo signal.

[0104] The signal processing unit 122 can adjust at least one of the transition period T3 and the idle period T4 to make the repetition frequency in the intermittent operation reach or exceed a preset set frequency. For example, such as Figure 5 As shown, by shortening the transition period T3 and the idle period T4, the reduction in repetition frequency can be suppressed. The set frequency can be above the upper limit of the human audible frequency range. The audible frequency range can be above 20 Hz and below 20 kHz. In this case, the upper limit is 20 kHz. The set frequency can also be above 10 kHz. The set frequency can be above 16 kHz or above, or above 20 kHz. Through this control, the control sound of lens 102 that can be heard by the user can be suppressed.

[0105] The repetition frequency in intermittent operation can also be higher than or equal to the calculation frequency at which the calculation unit 124 calculates the lens drive amount. The calculation frequency in the calculation unit 124 refers to the frequency at which the calculation unit 124 updates the lens drive amount. By updating the lens drive amount, the drive unit 126 controls the position of the lens 102. Therefore, the calculation frequency in the calculation unit 124 corresponds to the control frequency at which the lens 102 is controlled. Sometimes the calculation frequency in the calculation unit 124 is set higher than the upper limit of the audible frequency so as not to generate control sounds of the lens 102 in the audible frequency band. By setting the repetition frequency in the position detection unit 130 to be higher than or equal to the calculation frequency, the repetition frequency can be set higher than the audible frequency.

[0106] The conversion period T3 can be shortened by reducing the accuracy of the AD conversion in the AD converter 136. For example, in the case of an AD converter 136 that is an oversampling mode or a ΔΣ modulation mode AD converter 136, the output rate of the AD converter 136 can be increased by reducing the oversampling ratio. The output rate is represented, for example, by the reciprocal of the conversion period T3. In the oversampling mode AD converter 136, the lens position signal is sampled with a number of samples that is significantly greater than the number of samples corresponding to the Nyquist rate. The more samples (the higher the oversampling ratio), the higher the resolution of the output current position signal. The resolution of the digital signal is represented by the number of bits corresponding to the value greater than the quantization error component.

[0107] On the other hand, the more samples, the longer the time required to generate a single current position signal (conversion period T3) becomes. When the position detection unit 130 operates intermittently, the signal processing unit 122 can reduce the oversampling ratio of the AD converter 136 compared to continuous operation, thereby increasing the output rate. When the position detection unit 130 operates intermittently, the signal processing unit 122 can also reduce the resolution of the AD converter 136 compared to continuous operation, thereby increasing the output rate.

[0108] The resolution of the AD converter 136 can be adjusted by the oversampling ratio, but it can also be adjusted using other methods. The AD converter 136 can be a Nyquist-based AD converter. In a Nyquist-based AD converter, the input signal is sampled at the Nyquist frequency. Even in the Nyquist-based AD converter 136, the output rate can be increased by reducing the number of times the input signal is sampled to generate a current position signal, thereby lowering the resolution of the AD converter 136.

[0109] Figure 6This diagram illustrates another example of the operation of the position detection unit 130. In this example, the position detection unit 130 has a low-speed intermittent operation mode and a high-speed intermittent operation mode as a second operation mode. In the low-speed intermittent operation mode, the repetition frequency (1 / T2) is less than the set frequency. In the high-speed intermittent operation mode, the repetition frequency (1 / T2) is greater than or equal to the set frequency. The set frequency is, for example, the upper limit of the audible frequency. The low-speed intermittent operation mode can be combined with... Figure 4 The second action mode is the same as the high-speed intermittent action mode, which can be the same as the second action mode. Figure 5 The second action pattern is the same.

[0110] The signal processing unit 122 can switch between a high-speed intermittent operation mode and a low-speed intermittent operation mode based on an external signal. The external signal is a signal input from outside the signal processing unit 122. The external signal can be input from the central control unit 202 via the communication path 210. The external signal can be generated, for example, based on user operations. For instance, the low-speed intermittent operation mode can be selected when the user is not concerned about noise. Alternatively, the low-speed intermittent operation mode can be implemented to determine whether the intermittent operation mode is functioning correctly via voice.

[0111] Figure 7 This diagram illustrates a control example of the position detection unit 130. As described above, the signal processing unit 122 controls power consumption by adjusting the conversion accuracy in the AD converter 136. The signal processing unit 122 can generate a power control signal PC2, which adjusts at least one of the oversampling ratio, number of samples, resolution, and output rate in the AD converter 136. In this example, the signal processing unit 122 can also generate a power control signal PC1 to control the power consumption in the position sensor 132.

[0112] Figure 8 This is a diagram showing another structural example of the position detection unit 130. In this example, the position detection unit 130, in addition to having… Figure 3 In addition to the structure shown, it also includes a chopper modulator 133 and a chopper demodulator 135. Furthermore, the amplifier 134 in this example is a differential amplifier.

[0113] Figure 9 This diagram illustrates an example of the structure of the chopper modulator 133, amplifier 134, and chopper demodulator 135. In this example, the position sensor 132 detects the lens position and outputs a differential detection signal (Vin, -Vin).

[0114] The chopper modulator 133 modulates the polarity of the differential detection signal (Vin, -Vin) according to the chopping frequency. In this example, the chopper modulator 133 outputs the detection signal Vin as the output signal Vn during the period when the chopping clock CLK1 is H logic and the chopping clock CLK2 is L logic, and outputs the inverted detection signal -Vin as the output signal Vn during the period when the chopping clock CLK1 is L logic and the chopping clock CLK2 is H logic. The chopping clock CLK2 is a clock whose waveform is inverted from that of the chopping clock CLK1. The chopper modulator 133 outputs the detection signal Vin as the output signal -Vn during the period when the chopping clock CLK1 is L logic and the chopping clock CLK2 is H logic, and outputs the inverted detection signal -Vin as the output signal -Vn during the period when the chopping clock CLK1 is H logic and the chopping clock CLK2 is L logic.

[0115] Amplifier 134 amplifies the differential signal (Vampin, -Vampin) output from chopper modulator 133 by a magnification of more than 1, and outputs a differential signal (Vampout, -Vampout). Chopper demodulator 135 demodulates the output of amplifier 134 according to the chopping frequency. In this example, chopper demodulator 135 outputs the differential signal -Vampout as the detection signal Vout during the period when chopper clock CLK1 is H logic and chopper clock CLK2 is L logic, and outputs the differential signal Vampout as the detection signal Vout during the period when chopper clock CLK1 is L logic and chopper clock CLK2 is H logic. Chopper demodulator 135 outputs the differential signal -Vampout as the detection signal -Vout during the period when chopper clock CLK1 is H logic and chopper clock CLK2 is L logic, and outputs the differential signal Vampout as the detection signal -Vout during the period when chopper clock CLK1 is H logic and chopper clock CLK2 is L logic. In this example, the AD converter 136 converts the differential detection signal (Vout, -Vout) output by the chopper demodulator 135 into digital data.

[0116] Figure 10 This is a diagram showing an example of the time waveform and spectrum of a differential signal (Vampout, -Vampout). The differential signal (Vampout, -Vampout) is the amplified version of the differential signal (Vampin, -Vampin). In this case, the amplifier's offset or noise components are also amplified.

[0117] Figure 11This is a diagram showing an example of the time waveform and spectrum of the detection signal (Vout, -Vout). The detection signal (Vout, -Vout) corresponds to the signal after amplification of the detection signal (Vin, -Vin). Therefore, the detection signal (Vout, -Vout) has a peak at frequency ωin. On the other hand, noise components shift to the high-frequency band corresponding to the chopping frequency ωc. Therefore, the noise components shifted to the high-frequency band can be removed by a low-pass filter, thereby extracting the frequency components of the detection signal (Vout, -Vout).

[0118] As described above, the signal processing unit 122 can control the output rate of the AD converter 136, thereby controlling the power consumption of the position detection unit 130. In this case, the change in chopping frequency before and after the change in the output rate of the AD converter 136 can be less than the change in the output rate.

[0119] Figure 12 This is a graph showing the frequency characteristics of the AD converter 136 and the chopping frequency when the output rate of the AD converter 136 is high or low. The chopping frequency remains constant before and after the output rate of the AD converter 136 changes. Through this control, the chopping modulation frequency is maintained even when the power consumption of the position detection unit 130 is reduced, thus allowing for high-precision removal of offsets or low-frequency noise components in the detection signal.

[0120] Figure 13 This diagram illustrates another structural example of camera module 110. The camera module 110 in this example includes a first lens drive unit 120-a and a second lens drive unit 120-b that drive a shared lens 102. In this example, the camera module 110 may provide a lens drive unit 120 for each drive element 106. Other structures are similar to... Figure 2 The examples are the same. Furthermore, the structure of each lens drive unit 120 is the same as... Figures 2 to 12 The same as any of the examples described herein.

[0121] In this example, the power consumption of either the first lens drive device 120-a or the second lens drive device 120-b can be controlled to be less than that of the other, based on the status information of the camera device 100. For example, when the camera module 110 is not used to generate image data, the signal processing unit 122 can reduce the power consumption of either the first lens drive device 120-a or the second lens drive device 120-b. In another example, the power consumption of both the first lens drive device 120-a and the second lens drive device 120-b can also be reduced.

[0122] The central control unit 202 and the like can also determine, based on status information, which of the first lens drive unit 120-a and the second lens drive unit 120-b should have its power consumption reduced. In this example, the status information may include detection data generated by the image sensor 108 when both the first lens drive unit 120-a and the second lens drive unit 120-b are operating with low power consumption. The central control unit 202 can also determine, based on the detection data, which of the first lens drive unit 120-a and the second lens drive unit 120-b should be operated with low power consumption in the future. For example, the central control unit 202 and the like can detect in which direction the noise included in the image of the detection data, which has increased due to the lens drive unit 120 operating with low power consumption, continuously exists in the image. The central control unit 202 and the like can reduce the power consumption of the lens drive unit 120, which controls the lens 102 in a direction different from the direction of the noise. Thus, while reducing power consumption in the camera module 110, the increase in noise included in the image of the detection data can be suppressed.

[0123] Furthermore, as a variation of the above embodiment, in the lens driving system 150, the calculation unit 124 may be installed in the central control unit 202. In this case, each lens driving device 120 may have a signal processing unit 122, a driving unit 126, and a position detection unit 130. This variation is the same as other embodiments described in this specification in that a lens driving system controls the relative position of a lens relative to an image sensor for a plurality of lenses (e.g., lens 102-1, lens 102-2) disposed corresponding to a plurality of image sensors (e.g., image sensor 108-1, image sensor 108-2) in a camera device 100. The lens driving system includes a plurality of lens driving devices (e.g., lens driving device 120-1, lens driving device 120-2) disposed corresponding to the plurality of lenses and controlling the relative position of each corresponding lens.

[0124] Furthermore, each lens driving device 120 includes: a position detection unit 130 for detecting the current relative position of the corresponding lens 102; a driving unit 126 for driving at least one of the lens 102 and the image sensor 108 based on a driving amount; and a signal processing unit 122 for outputting a power control signal to control the power consumption of the position detection unit 130. Furthermore, the following aspects are the same as in other embodiments described in this specification: each image sensor 108 outputs detection data, the communication path 210 of the lens driving device 120 is activated, and the system controls which image sensor 108's detection data is used to generate image data based on the camera device's status information; and the signal processing unit 122 of at least one lens driving device 120 changes the power consumption of the position detection unit 130 based on the status information.

[0125] In a modified example, the central control unit 202 acquires current position signals from each lens drive unit 120, derives the drive quantity of at least one of the lens 102 and the image sensor 108 based on the current position signals and the target position signals, and sends the derived drive quantity to each lens drive unit 120. Each lens drive unit 120 receives its corresponding drive quantity via communication path 210, and the drive unit 126 operates according to the received drive quantity. Ideally, the communication path 210 is a communication bus corresponding to I2C or a higher-speed communication standard such as I3C (Improved Inter-Integrated Circuit).

[0126] Furthermore, in the modified example, the calculation unit 124 can be implemented by software executed by the central control unit 202, or it can be installed externally as an IC chip attached to the central control unit 202. Additionally, in the modified example, for each lens driving device 120, the signal processing unit 122, the driving unit 126, and the position detection unit 130 can be integrated into a single IC chip.

[0127] The present invention has been described above using embodiments, but the scope of the present invention is not limited to the scope described in the embodiments. It will be apparent to those skilled in the art that various modifications or alterations can be made to the embodiments. As is clear from the claims, forms with such modifications or alterations may also be included within the scope of the present invention.

[0128] It is important to note that the execution order of actions, processes, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specification, and drawings can be implemented in any order, unless specifically indicated by "before" or "before," and the output of previous processes is not used for subsequent processes. Even if the flow of actions in the claims, specification, and drawings is described using terms such as "firstly," "nextly," etc., for convenience, it does not mean that they must be implemented in this order.

Claims

1. A lens driving system for controlling the relative position of a lens with respect to an image sensor in a camera device, the lens driving system comprising: Multiple lens driving devices are configured corresponding to the multiple lenses to control the relative positions of their respective lenses. Each lens drive unit has: The position detection unit detects the current relative position of the corresponding lens; The calculation unit calculates the driving amount of at least one of the lens and the image sensor based on the output of the position detection unit, i.e., the current position signal, and the input target position signal; A driving unit that drives at least one of the lens and the image sensor based on the driving amount; as well as The signal processing unit outputs a power control signal to control the power consumption of the position detection unit. Each image sensor outputs detection data, the communication path of the lens driving device is active, and based on the status information of the camera device, it controls which image sensor's detection data is used to generate image data. At least one of the signal processing units of the lens driving device causes a change in the power consumption of the position detection unit based on the state information.

2. The lens driving system according to claim 1, wherein, The signal processing unit, based on the state information, ensures that the power consumption of the corresponding position detection unit is less than that of the other position detection units, thereby enabling the drive unit to operate and become capable of generating image data.

3. The lens driving system according to claim 2, wherein, The signal processing unit, based on the status information, ensures that the power consumption of the corresponding position detection unit is less than that of the other position detection units, and then operates the drive unit to perform hand shakiness correction.

4. The lens driving system according to claim 2, wherein, When the signal processing unit makes the power consumption of the corresponding position detection unit less than the power consumption of the other position detection units, the power consumption of the corresponding drive unit is maintained.

5. The lens driving system according to claim 2, wherein, When the signal processing unit makes the power consumption of the corresponding position detection unit less than that of the other position detection units, it also reduces the power consumption of the corresponding drive unit.

6. The lens driving system according to claim 2, wherein, The signal processing unit reduces the power consumption of the position detection unit by reducing the total time the position detection unit operates to output the current position signal per unit time.

7. The lens driving system according to claim 2, wherein, The signal processing unit reduces the power consumption of the position detection unit by increasing the idle period during which the position detection unit does not perform the action of outputting the current position signal per unit time.

8. The lens driving system according to claim 6, wherein, The signal processing unit reduces the power consumption of the position detection unit by shortening the switching period during which the position detection unit operates to output the current position signal once.

9. The lens driving system according to claim 2, wherein, The plurality of lens driving devices includes a first lens driving device and a second lens driving device for controlling the relative position of the shared lenses. Based on the status information, the power consumption of either the first lens driving device or the second lens driving device is controlled to be less than the power consumption of the other.

10. The lens driving system according to claim 1, wherein, The position detection unit is capable of both continuous and intermittent operation. In the continuous operation, the transition period that runs to output the current position signal is continuous. In the intermittent operation, the idle period that runs when not outputting the current position signal is repeated along with the transition period. The signal processing unit reduces power consumption by causing the position detection unit to perform the intermittent operation.

11. The lens driving system according to claim 10, wherein, The repetition period, obtained by adding one transition period and one idle period in the intermittent action, is less than the period during which the current position signal is output once in the continuous action.

12. The lens driving system according to claim 11, wherein, The signal processing unit adjusts at least one of the transition period and the idle period so that the repetition frequency of the transition period and the idle period in the intermittent operation is at or above a preset set frequency.

13. The lens driving system according to claim 12, wherein, The set frequency is above the upper limit of the audible frequency range.

14. The lens driving system according to claim 12, wherein, The set frequency is above 10 kHz.

15. The lens driving system according to claim 10, wherein, The position detection unit has: A position sensor detects the relative position; and An analog-to-digital converter converts the relative positions into digital data. When the position detection unit performs the intermittent operation, the signal processing unit reduces the oversampling ratio of the analog-to-digital converter to increase the output rate compared to the continuous operation.

16. The lens driving system according to claim 10, wherein, The position detection unit has: A position sensor detects the relative position; and An analog-to-digital converter converts the relative positions into digital data. When the position detection unit performs the intermittent operation, the signal processing unit reduces the resolution of the analog-to-digital converter to increase the output rate compared to the continuous operation.

17. The lens driving system according to claim 10, wherein, The position detection unit has: A position sensor detects the relative position and outputs a differential detection signal; A chopper modulator modulates the polarity of the differential detection signal according to the chopping frequency; A differential amplifier amplifies and outputs the output of the chopper modulator; A chopper demodulator demodulates the output of the differential amplifier according to the chopper frequency; as well as An analog-to-digital converter converts the detection signal output from the chopper demodulator into digital data. The signal processing unit controls the output rate of the analog-to-digital converter, thereby controlling the power consumption of the position detection unit. The change in the chopping frequency before and after the change in the output rate of the analog-to-digital converter is less than the change in the output rate.

18. The lens driving system according to claim 17, wherein, Before and after the output rate of the analog-to-digital converter changes, the chopping frequency remains constant.

19. The lens driving system according to claim 10, wherein, The frequency at which the switching period and the idle period are repeated during the intermittent operation is greater than or equal to the calculation frequency at which the calculation unit calculates the driving amount of the lens.

20. The lens driving system according to claim 10, wherein, The position detection unit has a high-speed intermittent mode in which the repetition frequency during the transition period and the idle period is above the audible frequency, and a low-speed intermittent mode below the audible frequency. The signal processing unit switches between the high-speed intermittent mode and the low-speed intermittent mode based on external signals.

21. A portable device comprising a camera assembly, wherein the portable device, The camera device includes: Multiple image sensors; Multiple lenses are configured corresponding to the multiple image sensors; as well as The lens drive system controls the relative position of the lens with respect to the image sensor. The lens driving system includes multiple lens driving devices, which are configured corresponding to the multiple lenses and control the relative positions of their respective lenses. Each lens drive unit has: The position detection unit detects the current relative position of the corresponding lens; The calculation unit calculates the driving amount of at least one of the lens and the image sensor based on the output of the position detection unit, i.e., the current position signal, and the input target position signal; A driving unit that drives at least one of the lens and the image sensor based on the driving amount; as well as The signal processing unit outputs a power control signal to control the power consumption of the position detection unit. Each image sensor outputs detection data, the communication path of the lens driving device is active, and based on the status information of the camera device, it controls which image sensor's detection data is used to generate image data. At least one of the signal processing units of the lens driving device causes a change in the power consumption of the position detection unit based on the state information.

22. The portable device according to claim 21, further comprising: The central control unit controls each of the signal processing units based on the status information.

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