WO2015076055A1 - Imaging module, electronic device, and method for driving imaging module - Google Patents

Abstract

This invention provides an imaging module, an imaging device, and a method for driving an imaging module that make it possible to conserve power by using pulse-width modulation (PWM) to control a lens-driving mechanism without adding noise to images. An imaging module (10) in one mode of this invention has the following: a lens unit (12); an imaging element (14) that receives an optical image via said lens unit (12) and converts said optical image to an electrical signal; an imaging-element drive unit that outputs a drive signal to the imaging element (14) and reads out an image signal from the imaging element; a lens-driving mechanism that drives the lens unit (12); and a PWM control unit (50) that generates a PWM signal on the basis of a command value for controlling the lens unit (12) and controls the lens-driving mechanism on the basis of said PWM signal. The PWM control unit (50) generates a PWM signal that is synchronized with the drive signal outputted by the imaging-element drive unit.

Description

IMAGING MODULE, ELECTRONIC DEVICE, AND IMAGING MODULE DRIVE METHOD

The present invention relates to an imaging module, an electronic apparatus, and a driving method of the imaging module, and more particularly to a technique applied when performing pulse width modulation (PWM) control of a lens driving mechanism of a lens unit.

Conventionally, a motor control device that generates a PWM signal based on a reference clock, outputs the generated PWM signal as a drive signal to a drive unit (a three-phase inverter using three pairs of switching elements), and drives a three-phase motor Has been proposed (Patent Document 1).

Further, in Patent Document 1, in this type of motor control device, a multistage frequency divider circuit is generally used when generating a frequency division signal for counting from a reference clock signal. The motor control device having such a configuration is described as an issue that electromagnetic noise is generated due to many switch operations.

The invention described in Patent Document 1 does not use a frequency dividing circuit constituted by a multistage counting circuit (counter), but uses a simple circuit configuration by a logic output circuit that is a shift register, An appropriate duty ratio selection signal for setting a modulation factor (duty ratio) corresponding to the value is generated to reduce the scale of the circuit configuration while reducing the generation of noise.

On the other hand, Patent Document 2 discloses a small camera module mounted on a mobile phone, a portable game machine, a portable music player, or the like. This camera module includes a lens driving unit such as an autofocus function, a zoom function, and a camera shake correction function.

Patent Document 3 discloses a lens driving device that drives a lens barrel of a camera module. The lens driving device includes an autofocus lens driving unit and a camera shake correction unit that are driven by a voice coil motor (VCM).

JP 2013-219895 A JP 2013-88525 A JP 2013-24944 A

In an imaging module used for a mobile terminal such as a smartphone, when an optical image stabilization (OIS: Optical Image Stabilizer) mechanism is PWM-controlled, it was confirmed that noise was found on the captured image as a result of sensory evaluation.

Patent Document 1 describes a technique for reducing noise generated by PWM control, but does not describe an image sensor, and does not describe a technique for removing noise on an image obtained from the image sensor.

Patent Document 2 does not describe PWM control of a lens driving unit having a camera shake correction function or the like.

In addition, the lens driving device described in Patent Document 3 does not perform PWM control of a camera shake correction unit having a voice coil motor (VCM), so that noise associated with PWM control does not occur, but power consumption increases. On the other hand, if the OIS mechanism is simply PWM controlled, there is a problem that noise is added to the image as described above.

The present invention has been made in view of such circumstances, and achieves power saving by performing pulse width modulation (PWM) control of the lens driving mechanism of the lens unit, and noise is added to the image even if PWM control is performed. It is an object of the present invention to provide an imaging module, an electronic apparatus, and a driving method of the imaging module that can be avoided.

To achieve the above object, an imaging module according to an aspect of the present invention includes a lens unit, an imaging element that receives an optical image via the lens unit, and converts the received optical image into an electrical signal, and an imaging element An image sensor drive unit that outputs a drive signal to read an image signal from the image sensor, a lens drive mechanism that drives the lens unit, a pulse width modulation signal based on a command value that controls the lens unit, and a pulse width A PWM control unit that controls the lens driving mechanism based on the modulation signal, and the PWM control unit generates a pulse width modulation signal synchronized with the drive signal generated by the image sensor driving unit.

According to one aspect of the present invention, the pulse width modulation signal generated by the PWM control unit is synchronized with the drive signal generated by the image sensor driving unit, thereby reducing noise generated in the image. . In other words, when the pulse width modulation signal for PWM control of the lens driving mechanism and the drive signal for driving the image sensor are asynchronous, asynchronous noise occurs in the image. Was able to be reduced. As an example in which asynchronous noise appears prominently, there is horizontal stripe noise. When the pulse width modulation signal and the drive signal are asynchronous, a line on which noise is periodically generated is generated, and this appears as horizontal stripe noise. On the other hand, by synchronizing the pulse width modulation signal and the drive signal, periodicity can be eliminated and noise cannot be detected.

In the imaging module according to another aspect of the present invention, it is preferable that the imaging element driving unit and the PWM control unit generate a driving signal and a pulse width modulation signal based on a common reference clock, respectively. The PWM control unit can adjust the phase of the pulse width modulation signal so as to be synchronized with the drive signal generated by the image sensor driving unit, but generates the pulse width modulation signal based on a common reference clock. Thus, it can be easily synchronized with the drive signal.

In an imaging module according to still another aspect of the present invention, the PWM control unit preferably has a clock input terminal for inputting a reference clock. That is, the PWM controller does not need to have a unique oscillator and can use an external clock (common reference clock).

In the imaging module according to still another aspect of the present invention, the lens driving mechanism preferably includes a voice coil motor that is subjected to pulse width modulation control by a PWM control unit.

In the imaging module according to still another aspect of the present invention, the lens driving mechanism is a camera shake correction mechanism that moves the lens unit in a plane orthogonal to the photographing optical axis direction. As a result, it is possible to capture an image without image blur due to camera shake and without noise.

In the imaging module according to still another aspect of the present invention, the pixel pitch of the imaging element is 1 μm or less.

An image pickup module mounted on a smartphone or the like is very small, and one pixel of the image pickup device tends to be small as the number of pixels increases. When the pixel pitch is 1 μm or less (when the pixel is small), the amount of incident light per pixel is small, and the photoelectrically converted signal obtained from one pixel is also small, so the signal-to-noise ratio (S / N) is small. The present invention is effective as a noise countermeasure for an imaging module including an imaging device having pixels with a pixel pitch of 1 μm or less.

An electronic device according to still another aspect of the present invention includes the imaging module according to any one of the above and an electronic device main body on which the imaging module is mounted. As an electronic device, a smart phone, a mobile phone, a tablet terminal, a personal digital assistant (PDA), a glasses-type information terminal, a portable game machine, a portable music player, a camera clock, and the like can be considered. Since these devices are small and the image pickup module is also small, the image pickup element and the lens driving mechanism are close to each other, and noise is easily applied to the image. However, according to the present invention, it is possible to prevent noise from being applied to the image.

In an electronic device according to still another aspect of the present invention, the electronic device main body includes a reference clock generation unit that generates a reference clock, and the reference clock generation unit supplies a reference clock to each of the image sensor driving unit and the PWM control unit. Supply.

In the electronic device according to still another aspect of the present invention, the electronic device main body receives an image signal output from the imaging module and performs signal processing on the image signal, and the signal processing unit performs signal processing. And a recording unit for recording the image signal.

The invention according to still another aspect of the present invention includes a lens unit, an image sensor that receives an optical image via the lens unit, converts the received optical image into an electrical signal, and outputs a drive signal to the image sensor. An image sensor drive unit that reads an image signal from the image sensor, a lens drive mechanism that drives the lens unit, a pulse width modulation signal based on a command value that controls the lens unit, and a lens drive based on the pulse width modulation signal In a driving method of an imaging module including a PWM control unit that controls a mechanism, a pulse width modulation signal generated by the PWM control unit is synchronized with a driving signal generated by an imaging element driving unit.

According to the present invention, since the pulse width modulation signal generated by the PWM control unit is synchronized with the drive signal for driving the image sensor, noise generated in the image when the lens drive mechanism is PWM controlled is reduced. Can do.

Sectional perspective view which shows the structure of the imaging module which concerns on this invention Schematic diagram conceptually showing an embodiment of an imaging module according to the present invention The figure which shows the example of whole structure containing the peripheral circuit of an image pick-up element Block diagram showing an embodiment of a PWM controller Timing chart showing PWM frequency and image sensor drive frequency signals generated based on the reference clock Timing chart showing PWM frequency and PWM signals having various duty ratios 1 is a block diagram showing an embodiment of an electronic device equipped with an imaging module Schematic diagram conceptually showing a conventional imaging module A diagram schematically showing the presence or absence of noise in the image The figure which shows the external appearance of the smart phone which is embodiment of an electronic device Block diagram showing the configuration of the smartphone

Hereinafter, embodiments of an imaging module, an electronic device, and an imaging module driving method according to the present invention will be described with reference to the accompanying drawings.

<Mechanism of imaging module>
FIG. 1 is a cross-sectional perspective view showing the structure of an imaging module according to the present invention.

The imaging module 10 mainly includes a lens unit 12, an imaging element 14, an optical camera shake correction (OIS) mechanism (lens driving mechanism) 16, a focus adjustment mechanism 18, and the like. Of the X, Y, and Z axes in the three-axis orthogonal coordinate system shown in FIG. 1, the Z axis is the same axis as the photographic optical axis O, and the XY axis is an axis orthogonal to the photographic optical axis O. It is.

In FIG. 1, a sensor substrate 22 is attached on a base 20, and an image sensor 14 is disposed on the sensor substrate 22. In the image pickup device 14 of this example, primary color filters of three primary colors of red (R), green (G), and blue (B) are arranged in a predetermined pattern for each pixel (Bayer arrangement, G stripe R / G complete checkerboard, X -Trans (registered trademark) array, honeycomb array, etc.) and is composed of a CMOS (complementary metal-oxide semiconductor) type image sensor. The image sensor is not limited to a CMOS image sensor, but may be a CCD (charge coupled device) image sensor.

A base member 26 having an opening corresponding to the image sensor 14 is fixed on the sensor substrate 22, and an infrared cut filter 28 is disposed in the opening of the base member 26.

The base member 26 is provided with a pair of OIS drive coils 28X and 28Y in the X-axis direction and the Y-axis direction via a coil substrate or the like.

On the other hand, OIS drive magnets 32X and 32Y are disposed on the lower surface of the magnet holder 30 so as to face the OIS drive coils 28X and 28Y, respectively, and an autofocus (AF) magnet 34 is disposed on the inner side thereof. Has been.

Further, a cover 38 is attached to the upper surface side of the magnet holder 30 with a metal plate 36 interposed therebetween.

Between the base member 26 side (fixed side) and the magnet holder 30 side (movable side), four wire springs 40 (only one is shown) are arranged. , Suspended so as to be movable on the XY plane.

The lens unit 12 of this example is configured by housing five lens groups in a lens barrel 42.

An AF coil 44 is disposed around the lens barrel 42.

The lens unit 12 is housed inside the magnet holder 30 and the like, and is biased toward the base member 26 by a leaf spring (not shown) integrally formed with the metal plate 36, and has a photographing optical axis O (Z axis). ) It is guided to move in the direction.

That is, the lens unit 12 and the magnet holder 30 are suspended by four wire springs 40 and guided so as to be movable within a plane (XY plane) orthogonal to the photographing optical axis O. It is guided so as to be movable in the direction of the photographing optical axis O (Z axis).

The OIS drive coils 28X and 28Y and the OIS drive magnets 32X and 32Y function as a voice coil motor (VCM) of the OIS mechanism 16, and the AF magnet 34 and the AF coil 44 are VCMs of the focus adjustment mechanism 18. Function as.

When the VCM of the OIS mechanism 16 is driven, the lens unit 12 can move in a plane orthogonal to the photographing optical axis O to correct camera shake, and when the VCM of the focus adjustment mechanism 18 is driven. The lens unit 12 can move in the photographing optical axis O direction to perform focus adjustment.

[Embodiment]
FIG. 2 is a schematic view conceptually showing an embodiment of the imaging module 10 according to the present invention.

As described above, the lens unit 12 is guided so as to be movable in a plane orthogonal to the photographing optical axis O, and is guided so as to be movable in the direction of the photographing optical axis O.

When the VCM 16a that is an actuator of the OIS mechanism 16 is driven, the lens unit 12 can move in a plane orthogonal to the photographing optical axis O to correct camera shake, and the VCM 18a of the focus adjustment mechanism 18 is driven. Then, the lens unit 12 can move in the direction of the photographing optical axis O to perform focus adjustment.

In this example, the image sensor driving unit (not shown) of the image sensor 14 mounted on the sensor substrate 22 and the PWM control unit 50 that performs pulse width modulation (PWM) control of the OIS mechanism 16 are commonly used from the outside. Clock CLK is supplied.

The image sensor driving unit generates various drive signals for driving the image sensor 14 based on a reference clock CLK input from the outside, and reads an image signal from the image sensor 14 using the generated drive signal.

The PWM control unit 50 generates a pulse width modulation signal (PWM signal) based on a reference clock CLK input from the outside and a command value for controlling the lens unit 12, and controls the OIS mechanism 16 based on the generated PWM signal. Control.

<Image sensor>
FIG. 3 is a diagram illustrating an overall configuration example including peripheral circuits of the image sensor 14.

The image area 140 of the image sensor 14 is an area where an optical image is received (imaged) via the lens unit 12. In the image area 140, pixels 142 made up of a plurality of photoelectric conversion elements are two-dimensionally arranged. The pixel pitch P of the pixels 142 of the image sensor 14 of this example is 1 μm, and an image pickup module equipped with an image sensor having such a small pixel is not commercially available at present.

The image sensor 14 includes an image sensor drive unit such as a timing generator (TG) 143, a vertical driver 144, and a horizontal driver 145, a signal processing unit 146, and MIPI (Mobile Industry Processor Interface) 147. .

The TG 143 generates various drive signals for driving the image sensor 14 based on a reference clock CLK input from the outside, and supplies the generated drive signals to each part of the image sensor 14. As a result, the image signal is read out. Note that readout such as thinning readout and partial readout can also be performed.

The vertical driver 144 selects the pixels 142 for one row based on the image sensor driving signal applied from the TG 143, and reads the signals from the selected pixels 142. The signal processing unit 146 is provided corresponding to each column of the pixels 142, and performs correlated double sampling (CDS) processing on the signal for one row output from each column read by the vertical driver 144. To convert the processed signal into a digital signal. The signal processed by the signal processing unit 146 is stored in a memory provided for each column. The horizontal driver 145 performs control to sequentially read out signals for one row stored in the memory of the signal processing unit 146 in accordance with the image sensor driving signal applied from the TG 143 and output the signals to the MIPI 147. The MIPI 147 transmits a digital signal in accordance with MIP (Mobile Industry Processor).

<PWM controller>
FIG. 4 is a block diagram illustrating an embodiment of the PWM control unit 50.

As shown in FIG. 4, the PWM control unit 50 mainly includes a central processing unit (CPU) 51, a PWM signal generation unit 52, and a driver 54, and includes an input terminal 55, a lens position input terminal 56, and a clock input terminal. 57 and an output terminal 58.

The imaging module 10 is provided with a gyro sensor 60 that detects angular velocities in the direction around the X axis and the direction around the Y axis of the lens unit 12, and from the gyro sensor 60 via the input terminal 55 around the X axis of the lens unit 12. An angular velocity signal indicating the angular velocity in the direction and the direction around the Y axis is applied to the CPU 51.

In addition, the imaging module 10 is provided with a hall element 62 that detects the positions of the lens unit 12 in the X-axis direction and the Y-axis direction, and the X of the lens unit 12 is transmitted from the hall element 62 via the lens position input terminal 56. Position data indicating the current position in the axial direction and the Y-axis direction is added to the CPU 51.

The CPU 51 integrates the angular velocity signal output from the gyro sensor 60 to calculate the deflection angle of the lens unit 12 around the X axis and the Y axis, and cancels the calculated deflection angle of the lens unit 12. A lens displacement amount corresponding to linear movement in the X-axis direction and the Y-axis direction is calculated. The CPU 51 calculates a control target value (command value) of the lens unit 12 based on the calculated lens displacement amount and the position data of the lens unit 12 input from the lens position input terminal 56, and the calculated command value is PWM. Output to the signal generator 52.

A reference clock CLK is applied from the clock input terminal 57 to the PWM signal generation unit 52. This reference clock CLK is the same as the reference clock CLK applied to the TG 143 of the image sensor 14.

The PWM signal generation unit 52 generates a PWM signal for controlling the OIS mechanism 16 based on the control target value (command value) of the lens unit 12 input from the CPU 51 and the reference clock CLK input from the clock input terminal 57. To do. The generated PWM signal is applied to the driver 54.

The driver 54 adjusts the amount of drive current supplied to the VCM 16a by adjusting the on time and the off time of the drive current supplied to the pair of VCMs 16a of the OIS mechanism 16 according to the duty ratio of the input PWM signal. Thereby, the OIS mechanism 16 is driven and the position of the lens unit 12 is controlled.

FIG. 5 is a timing chart showing the signal waveform of the PWM frequency and the signal waveform of the image sensor driving frequency generated based on the reference clock.

In the example shown in FIG. 5, the PWM frequency signal is a signal obtained by dividing the frequency of the reference clock CLK by 1/8, and the image sensor driving frequency signal is multiplied by 5 times the frequency of the reference clock CLK ( (Multiplied by 5).

FIG. 6 is a timing chart showing a PWM frequency signal waveform and PWM signals having various duty ratios.

The duty ratio of the PWM signal is determined by a command value that is a control target value, and the PWM signal generation unit 52 (FIG. 4), based on the determined command value and the reference clock CLK input from the clock input terminal 57, A PWM signal having a PWM frequency is generated.

As shown in FIG. 5, the PWM frequency signal generated by dividing or multiplying the common reference clock CLK and the image sensor driving frequency signal are different in frequency, but are synchronized.

Thereby, during the PWM control of the OIS mechanism 16 by the PWM signal of the PWM frequency, when the image signal is read from the image sensor 14 based on the signal of the image sensor drive frequency, the noise caused by the PWM control is read out. You can avoid getting on.

<Electronic equipment>
FIG. 7 is a block diagram illustrating an embodiment of an electronic device 100 in which the imaging module 10 having the above configuration is mounted on an electronic device main body such as a portable terminal. Note that FIG. 7 shows only a part that functions as an imaging device of the electronic device 100.

In FIG. 7, a central processing unit (CPU) 102 is a part that performs overall control of the entire apparatus in accordance with an operation input from the operation unit 104 and a predetermined program, and includes auto focus (AF), automatic exposure (AE), and auto white balance. It also functions as a part that performs calculation and control for (AWB).

The CPU 102 is provided with an oscillator 102a, and the CPU 102 uses a high frequency signal from the oscillator 102a as a clock source for a digital circuit and a timing source for a clock (quartz). In this example, the CPU 102 includes a reference clock generation unit that generates a reference clock CLK based on a high frequency signal from the oscillator 102 a, and supplies the generated reference clock CLK to the imaging module 10 via the bus 103.

Further, a RAM (Random Access Memory) 108 and a ROM (Read Only Memory) 110 are connected to the CPU 102 via a bus 103 and a memory interface (I / F) 106. The RAM 108 is used as a program development area and a calculation work area for the CPU 102, and is also used as a temporary storage area for image data. The ROM 110 stores programs executed by the CPU 102, various data necessary for control, various constants / information related to imaging operations, and the like.

The imaging module 10 performs an imaging operation or the like according to a command from the CPU 102, and outputs an image signal (RGB RAW data) read from the imaging element 14. This raw data is temporarily stored in the RAM 108 via the bus 103 and the memory I / F 106.

The RGB RAW data stored in the RAM 108 is input to the digital signal processing unit 112, where gain processing including offset processing, white balance correction, sensitivity correction, gamma correction processing, demosaic processing, RGB / YC conversion Digital signal processing such as processing is performed. The demosaic process is a process for calculating all color information for each pixel from a mosaic image corresponding to the color filter array of a single-plate color image sensor, and is also called a demosaicing process or a synchronization process. For example, in the case of an image sensor made up of three color filters of RGB, this is a process of calculating color information for all RGB for each pixel from a mosaic image made of RGB.

When RAW data recording is selected, the RAW data is recorded in the memory card 116 via the external memory I / F 114 in the RAW file format.

The operation unit 104 includes a shutter button, a mode selection switch for selecting a shooting mode and a playback mode, a menu button for displaying a menu screen on the liquid crystal display unit (LCD) 118, and a multi-function for selecting a desired item from the menu screen. The cross key etc. are included. An output signal from the operation unit 104 is input to the CPU 102 via the bus 103, and the CPU 102 performs appropriate processing such as shooting and reproduction based on the input signal from the operation unit 104.

The image data (luminance signal Y, color difference signals Cr, Cb) processed by the digital signal processing unit 112 is given to the compression / decompression processing circuit 124, where it is compressed according to a predetermined compression format (for example, JPEG system). . The compressed image data is recorded in the memory card 116 via the external memory I / F 114 in the format of an image file (for example, a JPEG file).

Further, the LCD 118 displays a video (live view image) during preparation for imaging by an image signal applied via the LCD interface 126, and a JPEG file or RAW file recorded on the memory card 116 in the playback mode. The image is read and displayed. The compressed image data stored in the JPEG file is decompressed by the compression / decompression circuit 124 and output to the LCD 118. The RAW data stored in the RAW file is RAW developed by the digital signal processing unit 112. Is output to the LCD 118.

<Comparative Example 1>
FIG. 8 is a schematic diagram conceptually showing a conventional imaging module 10A, which is used for comparison with the imaging module 10 according to the present invention shown in FIG. In FIG. 8, the same reference numerals are given to portions common to the imaging module 10 shown in FIG. 2, and detailed description thereof is omitted.

The PWM control unit 50 that drives the OIS mechanism 16 (VCM 16a) of the imaging module 10 illustrated in FIG. 2 is supplied with a reference clock CLK (common to the reference clock CLK supplied to the imaging device 14) from the outside. The reference clock CLK is not supplied from the outside to the PWM control unit 50A of the imaging module 10A shown in FIG.

That is, the PWM control unit 50A has a PWM control unit oscillator, and obtains a clock for generating a PWM signal based on a high-frequency signal from the oscillator.

Accordingly, the PWM signal generated by the PWM control unit 50A and the drive signal of the image sensor 14 generated based on the reference clock CLK are asynchronous, and noise is added to the image as a result of sensory evaluation on the captured image. It was confirmed.

9 (a) and 9 (b) are diagrams schematically showing the presence or absence of noise in the image, and FIG. 9 (a) is an image acquired by the imaging module 10 according to the present invention. FIG. 9B shows an image acquired by the conventional imaging module 10A.

In the case of the imaging module 10 according to the present invention, noise could not be detected by synchronizing the PWM signal and the drive signal of the imaging device 14 (no noise was added to the image).

On the other hand, in the case of the conventional imaging module 10A, the PWM signal and the drive signal of the imaging element 14 become asynchronous, and asynchronous noise appears in the captured image.

As an example in which asynchronous noise appears prominently, there is horizontal stripe noise shown in part (b) of FIG. 9, but in the case of the conventional imaging module 10 </ b> A, horizontal stripe noise has occurred. This is because the PWM signal and the drive signal of the image sensor 14 are asynchronous, so that a line on which noise is periodically generated is generated, which appears as horizontal stripe noise.

<Comparative example 2>
Sensory evaluation of the captured image was performed by appropriately combining the size of the pixel pitch of the image sensor and the presence or absence of synchronization between the PWM signal and the drive signal of the image sensor.

Table 1 below shows the results of sensory evaluation.

[About sensory evaluation results]
A: There is no noise in the image.

B: Although there is a slight noise, there is no problem in viewing.

C: There is noise in the image and it is unbearable for viewing.

As shown in [Table 1], when the pixel pitch was 1.4 μm, no noise was added to the image regardless of the synchronization between the PWM signal and the drive signal of the image sensor. This is probably because the sensor signal (analog signal) subjected to photoelectric conversion is large and the S / N is large because the size of one pixel is large.

When the pixel pitch is 1.12 μm and 0.9 μm, the noise generated in the image is reduced by synchronizing the PWM signal and the drive signal of the image sensor as compared with the asynchronous case.

As shown in FIG. 3 and the like, the pixel pitch P of the image sensor 14 of this example is 1 μm. However, from the result of the sensory evaluation, when the pixel pitch is 1 μm or less, the PWM signal and the drive signal of the image sensor are Synchronizing is particularly effective.

Examples of the electronic device 100 such as a portable terminal include a smartphone, a mobile phone, a tablet terminal, a personal digital assistant (PDA), a glasses-type information terminal, a portable game machine, a portable music player, and a camera clock. Hereinafter, a smartphone will be described as an example, and will be described in detail with reference to the drawings.

<Configuration of smartphone>
FIG. 10 shows an appearance of a smartphone 500 that is an embodiment of the electronic device 100. A smartphone 500 illustrated in FIG. 10 includes a flat housing 502, and a display input in which a display panel 521 as a display unit and an operation panel 522 as an input unit are integrated on one surface of the housing 502. Part 520. The housing 502 includes a speaker 531, a microphone 532, an operation unit 540, and a camera unit 541. Note that the configuration of the housing 502 is not limited to this, and for example, a configuration in which the display unit and the input unit are independent, or a configuration having a folding structure and a slide mechanism can be employed.

FIG. 11 is a block diagram showing a configuration of the smartphone 500 shown in FIG. As shown in FIG. 11, the main components of the smartphone 500 include a wireless communication unit 510, a display input unit 520, a call unit 530, an operation unit 540, a camera unit 541, a storage unit 550, and an external input / output. Unit 560, GPS (Global Positioning System) reception unit 570, motion sensor unit 580, power supply unit 590, and main control unit 501. In addition, as a main function of the smartphone 500, a wireless communication function for performing mobile wireless communication via the base station device BS and the mobile communication network NW is provided.

The wireless communication unit 510 performs wireless communication with the base station apparatus BS accommodated in the mobile communication network NW according to an instruction from the main control unit 501. Using this wireless communication, transmission and reception of various file data such as audio data and image data, e-mail data, and reception of Web data and streaming data are performed.

The display input unit 520 displays images (still images and moving images), character information, and the like visually by the control of the main control unit 501, and visually transmits information to the user, and detects user operations on the displayed information. This is a so-called touch panel, and includes a display panel 521 and an operation panel 522. When viewing the generated 3D image, the display panel 521 is preferably a 3D display panel.

The display panel 521 uses an LCD (Liquid Crystal Display), an OELD (Organic Electro-Luminescence Display), or the like as a display device.

The operation panel 522 is a device that is placed so that an image displayed on the display surface of the display panel 521 is visible and detects one or a plurality of coordinates operated by a user's finger or stylus. When this device is operated by a user's finger or stylus, a detection signal generated due to the operation is output to the main control unit 501. Next, the main control unit 501 detects an operation position (coordinates) on the display panel 521 based on the received detection signal.

As shown in FIG. 10, the display panel 521 and the operation panel 522 of the smartphone 500 integrally form the display input unit 520, but the operation panel 522 is disposed so as to completely cover the display panel 521. ing. When this arrangement is adopted, the operation panel 522 may have a function of detecting a user operation even in an area outside the display panel 521. In other words, the operation panel 522 includes a detection area (hereinafter referred to as a display area) for an overlapping portion that overlaps the display panel 521 and a detection area (hereinafter, a non-display area) for an outer edge portion that does not overlap the other display panel 521. May be included).

Note that the size of the display area and the size of the display panel 521 may be completely matched, but it is not always necessary to match the two. In addition, the operation panel 522 may include two sensitive regions of the outer edge portion and the other inner portion. Further, the width of the outer edge portion is appropriately designed according to the size of the housing 502 and the like. Furthermore, examples of the position detection method employed in the operation panel 522 include a matrix switch method, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method. You can also

The call unit 530 includes a speaker 531 and a microphone 532, and converts a user's voice input through the microphone 532 into voice data that can be processed by the main control unit 501, and outputs the voice data to the main control unit 501, or a wireless communication unit 510 or the audio data received by the external input / output unit 560 is decoded and output from the speaker 531. Also, as shown in FIG. 10, for example, the speaker 531 and the microphone 532 can be mounted on the same surface as the surface on which the display input unit 520 is provided.

The operation unit 540 is a hardware key using a key switch or the like, and receives an instruction from the user. For example, the operation unit 540 is mounted on a lower portion and a lower side of the display unit of the housing 502 of the smartphone 500 and is turned on when pressed with a finger or the like, and is turned off when a finger is released with a restoring force such as a spring. It is a button type switch.

The storage unit 550 includes control programs and control data of the main control unit 501, address data in which names and telephone numbers of communication partners are associated, transmitted and received e-mail data, Web data downloaded by Web browsing, and downloaded contents Data is stored, and streaming data and the like are temporarily stored. The storage unit 550 includes an internal storage unit 551 with a built-in smartphone and an external storage unit 552 having a removable external memory slot. Each of the internal storage unit 551 and the external storage unit 552 constituting the storage unit 550 includes a flash memory type (flash memory type), a hard disk type (hard disk type), a multimedia card micro type (multimedia card micro type), It is realized using a storage medium such as a card type memory (for example, Micro SD (registered trademark) memory), RAM (Random Access Memory), ROM (Read Only Memory), or the like.

The external input / output unit 560 serves as an interface with all external devices connected to the smartphone 500, and communicates with other external devices (for example, universal serial bus (USB), IEEE1394, etc.) or a network. (For example, Internet, wireless LAN, Bluetooth (registered trademark), RFID (Radio Frequency Identification), Infrared Data Association (IrDA) (registered trademark), UWB (Ultra Wide Band) (registered trademark), ZigBee ( ZigBee) (registered trademark, etc.) for direct or indirect connection.

Examples of the external device connected to the smartphone 500 include a memory card connected via a wired / wireless headset, wired / wireless external charger, wired / wireless data port, card socket, and SIM (Subscriber). Identity Module Card) / UIM User Identity Module Card, external audio / video equipment connected via audio / video I / O (Input / Output) terminal, external audio / video equipment connected wirelessly, yes / no There are wirelessly connected smartphones, wired / wireless connected personal computers, wired / wireless connected PDAs, earphones, and the like. The external input / output unit may transmit data received from such an external device to each component inside the smartphone 500, or may allow data inside the smartphone 500 to be transmitted to the external device. it can.

The GPS receiving unit 570 receives GPS signals transmitted from the GPS satellites ST1 to STn in accordance with an instruction from the main control unit 501, executes positioning calculation processing based on the received plurality of GPS signals, A position consisting of longitude and altitude is detected. When the GPS receiving unit 570 can acquire position information from the wireless communication unit 510 or the external input / output unit 560 (for example, a wireless LAN), the GPS receiving unit 570 can also detect the position using the position information.

The motion sensor unit 580 includes, for example, a three-axis acceleration sensor, and detects the physical movement of the smartphone 500 in accordance with an instruction from the main control unit 501. By detecting the physical movement of the smartphone 500, the moving direction and acceleration of the smartphone 500 are detected. This detection result is output to the main control unit 501.

The power supply unit 590 supplies power stored in a battery (not shown) to each unit of the smartphone 500 in accordance with an instruction from the main control unit 501.

The main control unit 501 includes a microprocessor, operates according to a control program and control data stored in the storage unit 550, and controls each unit of the smartphone 500 in an integrated manner. Further, the main control unit 501 includes a mobile communication control function for controlling each unit of the communication system and an application processing function in order to perform voice communication and data communication through the wireless communication unit 510.

The application processing function is realized by the main control unit 501 operating in accordance with application software stored in the storage unit 550. Application processing functions include, for example, an infrared communication function that controls the external input / output unit 560 to perform data communication with the opposite device, an e-mail function that transmits and receives e-mails, and a web browsing function that browses web pages. .

The main control unit 501 also has an image processing function such as displaying video on the display input unit 520 based on image data (still image or moving image data) such as received data or downloaded streaming data. The image processing function is a function in which the main control unit 501 decodes the image data, performs image processing on the decoding result, and displays an image on the display input unit 520.

Further, the main control unit 501 executes display control for the display panel 521 and operation detection control for detecting a user operation through the operation unit 540 and the operation panel 522.

By executing the display control, the main control unit 501 displays an icon for starting application software, a software key such as a scroll bar, or a window for creating an e-mail. Note that the scroll bar refers to a software key for accepting an instruction to move the display portion of a large image that does not fit in the display area of the display panel 521.

Further, by executing the operation detection control, the main control unit 501 detects a user operation through the operation unit 540, or accepts an operation on the icon or an input of a character string in the input field of the window through the operation panel 522. Or a display image scroll request through a scroll bar.

Furthermore, by executing the operation detection control, the main control unit 501 causes the operation position with respect to the operation panel 522 to overlap with the display panel 521 (display area) or other outer edge part (non-display area) that does not overlap with the display panel 521. And a touch panel control function for controlling the sensitive area of the operation panel 522 and the display position of the software key.

The main control unit 501 can also detect a gesture operation on the operation panel 522 and execute a preset function according to the detected gesture operation. Gesture operation is not a conventional simple touch operation, but an operation that draws a trajectory with a finger or the like, designates a plurality of positions at the same time, or combines these to draw a trajectory for at least one of a plurality of positions. means.

The camera unit 541 is a digital camera that performs electronic photography using an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge-Coupled Device). The imaging module 10 described above can be applied to the camera unit 541.

The camera unit 541 converts image data obtained by shooting into compressed image data such as JPEG (JointoPhotographic coding Experts Group) under the control of the main control unit 501, and records the data in the storage unit 550. The data can be output through the external input / output unit 560 and the wireless communication unit 510. In the smartphone 500 shown in FIG. 10, the camera unit 541 is mounted on the same surface as the display input unit 520, but the mounting position of the camera unit 541 is not limited to this and may be mounted on the back surface of the display input unit 520. Alternatively, a plurality of camera units 541 may be mounted. Note that when a plurality of camera units 541 are mounted, the camera unit 541 used for shooting can be switched to shoot alone, or a plurality of camera units 541 can be used simultaneously for shooting.

In addition, the camera unit 541 can be used for various functions of the smartphone 500. For example, an image acquired by the camera unit 541 can be displayed on the display panel 521, or the image of the camera unit 541 can be used as one of operation inputs of the operation panel 522. Further, when the GPS receiving unit 570 detects the position, the position can also be detected with reference to an image from the camera unit 541. Further, referring to the image from the camera unit 541, the optical axis direction of the camera unit 541 of the smartphone 500 is determined without using the triaxial acceleration sensor or in combination with the triaxial acceleration sensor. It is also possible to determine the current usage environment. Of course, the image from the camera unit 541 can be used in the application software.

[Others]
In the present embodiment, the case where the VCM 16a that is the actuator of the OIS mechanism 16 is PWM driven has been described. However, the present invention can also be applied to the case where another actuator such as a piezoelectric actuator is PWM driven.

The present invention can be applied not only to the OIS mechanism 16 but also to the case where the focus adjustment mechanism 18 is PWM-controlled. In short, any lens driving mechanism that PWM-controls the lens unit can be applied.

Furthermore, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Imaging module, 12 ... Lens unit, 14 ... Image sensor, 16 ... Optical camera shake correction (OIS) mechanism, 18 ... Focus adjustment mechanism, 16a, 18a ... Voice coil motor (VCM), 50 ... Pulse width modulation (PWM) ) Control unit 52... PWM signal generation unit 54. Driver 57. Clock input terminal 100. Electronic equipment 102. Central processing unit (CPU) 102 a Oscillator 112 112 Digital signal processing unit 142 Pixel 143 Timing generator (TG) 144 Vertical driver 145 Horizontal driver

Claims (10)

1. A lens unit;
   An image sensor that receives an optical image through the lens unit and converts the received optical image into an electrical signal;
   An image sensor driving unit that outputs a drive signal to the image sensor and reads an image signal from the image sensor;
   A lens driving mechanism for driving the lens unit;
   A PWM control unit that generates a pulse width modulation signal based on a command value for controlling the lens unit, and controls the lens driving mechanism based on the pulse width modulation signal;
   The PWM control unit is an imaging module that generates a pulse width modulation signal synchronized with a driving signal output from the imaging element driving unit.
2. The imaging module according to claim 1, wherein the imaging element driving unit and the PWM control unit generate the driving signal and the pulse width modulation signal based on a common reference clock, respectively.
3. The imaging module according to claim 2, wherein the PWM control unit has a clock input terminal for inputting the reference clock.
4. The imaging module according to any one of claims 1 to 3, wherein the lens driving mechanism includes a voice coil motor that is subjected to pulse width modulation control by the PWM control unit.
5. The imaging module according to any one of claims 1 to 4, wherein the lens driving mechanism is a camera shake correction mechanism that moves the lens unit in a plane orthogonal to a photographing optical axis direction.
6. The imaging module according to any one of claims 1 to 5, wherein a pixel pitch of the imaging element is 1 µm or less.
7. The imaging module according to any one of claims 1 to 6,
   An electronic device body on which the imaging module is mounted;
   With electronic equipment.
8. The electronic device main body has a reference clock generation unit for generating a reference clock,
   The electronic device according to claim 7, wherein the reference clock generation unit supplies a reference clock to the image sensor driving unit and the PWM control unit, respectively.
9. The electronic device main body receives an image signal output from the imaging module, performs signal processing on the image signal, and a recording unit that records the image signal processed by the signal processing unit The electronic device according to claim 7 or 8, further comprising:
10. A lens unit, an image sensor that receives an optical image via the lens unit, converts the received optical image into an electric signal, an image sensor that outputs a drive signal to the image sensor and reads an image signal from the image sensor PWM that generates a pulse width modulation signal based on a command value that controls the driving unit, the lens unit that drives the lens unit, and controls the lens unit, and that controls the lens drive mechanism based on the pulse width modulation signal And a driving method of the imaging module including the control unit,
    An imaging module driving method for synchronizing a pulse width modulation signal generated by the PWM control unit with a driving signal output from the imaging element driving unit.

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