JP5224879B2 - Imaging device - Google Patents

Description

The present invention relates to a shooting device and, more particularly, to imaging apparatus performs imaging and focusing control by using a solid-state image pickup element used in the focusing control with use in imaging of the subject.

  In recent years, with the increase in resolution of solid-state imaging devices such as CCD (Charge Coupled Device) area sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, digital electronic still cameras, digital video cameras, mobile phones, PDAs (Personal Digital Assistants) , Portable information terminals) and other information devices having a photographing function are rapidly increasing. Note that an information device having the above photographing function is referred to as a photographing device.

  By the way, as a technique related to this type of imaging apparatus, Patent Document 1 provides a solid-state imaging apparatus capable of high-precision AF (Auto Focus) control without increasing the camera mechanism and power consumption. For this purpose, a technique for performing AF control by a phase difference AF method using image information obtained by a solid-state imaging device is disclosed.

  Hereinafter, the principle of the phase difference AF method will be described.

  As an example, as shown in FIG. 8, light from a specific point of the subject passes through the pupil corresponding to the point A and enters the point A and the light flux ΦLa and the point B through the pupil corresponding to the point B Into the light flux ΦLb entering. Since these two ray bundles are originally emitted from one point, if the focus of the camera lens is on the light receiving surface (imaging surface) of the solid-state imaging device, as shown in FIG. One point that is bundled with the same microlens is reached. However, for example, if the focal point of the camera lens is a distance x away from the light receiving surface of the solid-state imaging device, they are shifted from each other by 2θx as shown in FIG. On the other hand, if the focal point of the camera lens is a distance x away from the light receiving surface of the solid-state imaging device, the arrival point is shifted in the reverse direction by 2θx.

  Based on this principle, the image formed at the point A and the image formed at the point B coincide with each other when they are in focus by the camera lens, and shift when they are not in focus.

  Based on this principle, the solid-state imaging device disclosed in Patent Document 1 incorporates pixels having microlenses with different aperture positions into a basic array, and includes a basic (S1) pixel having a first aperture. An area in which the row of the basic array including the row of the array and the pixel (S2) having the second opening can be arranged adjacent to each other is provided. By calculating the shift amount of the row image signal from the S1 group and the row image signal from the S2 group in this area to obtain the shift amount of the camera lens, the AF control can be performed by moving the focus of the camera.

  The phase difference AF method is disclosed in many documents such as Japanese Patent Application Laid-Open No. 57-49841 in addition to Patent Document 1, and further description thereof is omitted.

On the other hand, in Patent Document 2, even if a lens with a short focal length and a small aperture diameter is used, the position of the in-focus portion other than the main subject is not affected by the position of the main subject according to the distance from the main subject. In order to obtain a naturally blurred image, detection means for detecting the main subject based on the distance to a plurality of subjects on the shooting surface, and shooting other than the portion where the detected main subject exists There is disclosed a technique for providing image processing means for performing image processing for blurring image data obtained by photographing a surface in accordance with the distance to the main subject so that the image data is blurred as the distance from the main subject increases.
JP 2000-156823 A JP-A-11-266388

  However, in the technique disclosed in Patent Document 1, since AF control is performed based on the phase difference between two different pixels, it is not necessarily possible to perform focus control with high accuracy. There was a problem that it was not limited.

  Further, even in the technique disclosed in Patent Document 2, image processing cannot be performed on a pixel-by-pixel basis, and thus processing for blurring an image other than the main subject is not always performed with high accuracy. There was a problem.

The present invention has been made to solve the above problems, and an object thereof is to provide a can that shooting device that performs processing related to focus with high precision.

In order to achieve the above object, the imaging apparatus according to claim 1 is arranged in a matrix, and the light receiving unit is in units of pixels with respect to at least one of a horizontal direction, a vertical direction, and an oblique direction. is equally divided into a plurality of divided regions, and each light receiving portion a plurality of light receiving element that F values are provided light-receiving portion for a predetermined value or more lenses in central, each of the plurality of light receiving elements 1 provided corresponding in-one, with an output means to output a plurality of micro lenses for forming a subject image, and a signal indicating the amount of received light obtained by the plurality of light receiving elements corresponding light-receiving element A solid-state image sensor; and a separated image information generating unit configured to generate separated image information separated for each of the plurality of divided areas based on a signal output from the solid- state image sensor; and the separated image information and the central portion Set in Captured image information generating means for generating captured image information by adding image information from the received light receiving unit for each corresponding pixel, storage means for storing the generated separated image information and the generated captured image information, Based on the separated image information stored in the storage means, a derivation means for deriving a shift amount of the subject image for each of the light receiving elements of the solid-state imaging device, and for each light receiving element obtained by the derivation means And image processing means for performing image processing for increasing the blurring amount as the deviation amount increases with respect to the captured image information stored in the storage means based on the deviation amount.

  According to the solid-state imaging device of the first aspect, the plurality of light receiving elements are each arranged in a matrix, and the light receiving unit is equally divided into a plurality of divided regions in units of pixels.

  In the present invention, a subject image is formed on the corresponding light receiving element by the plurality of microlenses provided in one-to-one correspondence with the plurality of light receiving elements, respectively, while the subject image is obtained by the plurality of light receiving elements. A signal indicating the received light amount is output by the output means.

  Therefore, by using the solid-state imaging device according to the present invention, the shift amount in the phase difference AF method described above can be obtained in units of pixels. As a result, this shift amount is used for AF control and an image that blurs the background portion of the captured image. By executing the process related to focusing such as the process, the process can be performed with higher accuracy.

  Thus, according to the solid-state imaging device according to claim 1, a plurality of light-receiving elements that are arranged in a matrix and in which the light-receiving unit is equally divided into a plurality of divided regions in units of pixels, and A plurality of microlenses that are provided in a one-to-one correspondence with the plurality of light receiving elements, and that output a signal indicating the amount of light received by the plurality of light receiving elements, and a plurality of microlenses that form a subject image on the corresponding light receiving elements. And the processing relating to focusing can be performed with high accuracy.

The present invention is preferable as defined in claim 1, equally divided plurality of light receiving elements, the horizontal direction the light receiving unit in units of pixels, for at least one direction of the vertical, and oblique directions May be. When the light receiving unit is divided with respect to the horizontal direction, the main subject is long in the vertical direction, and the subject having a background portion on at least one of the left and right sides thereof (hereinafter referred to as “vertical subject”) is highly accurate. Focus control can be performed. Further, when the light receiving unit is divided with respect to the vertical direction, the main subject is long in the horizontal direction, and a subject having a background portion at least in the upper and lower sides thereof (hereinafter referred to as “lateral subject”) is high. Focus control can be performed with high accuracy. Furthermore, when the light receiving unit is divided with respect to the oblique direction, it is possible to perform focus control with high accuracy on both the vertical subject and the horizontal subject, and the pitch between the corresponding divided regions. As a result, the focusing control can be performed with higher accuracy.

Further, the present invention is preferable as defined in claim 1, wherein the plurality of light receiving elements, each said light receiving section (hereinafter, "first light-receiving portion" hereinafter.) F value in a central portion of the (Fade Number ) is a light receiving portion of the lens on the predetermined value or more (hereinafter, referred to as a "second light-receiving portion.") it may be further provided. Accordingly, the dynamic range of the image captured by the solid-state imaging device is increased by adding the received light amount obtained by the second light receiving unit and the received light amounts obtained by the plurality of divided regions in the first light receiving unit. Can be enlarged.

In the present invention, as in the invention described in claim 2 , the plurality of light receiving elements may have a honeycomb structure. Thereby, compared with the case where the plurality of light receiving elements have a true pixel array structure, the area of the light receiving portion of each pixel can be further increased, and as a result, sensitivity characteristics and saturation characteristics can be improved. As a result of the narrower pixel pitch, the resolution can be increased.

Further, according to the present invention, as in the invention described in claim 3 , the output means divides a signal indicating the amount of received light obtained by each of the plurality of divided regions for each of the plurality of light receiving elements. The second output that is output in a combined state with the first output that is output in a state where each region is separated may be selectively performed. As a result, there is no need to provide an external means for adding a signal indicating the amount of received light obtained by each divided region. As a result, the solid-state imaging device can be used more easily.

Meanwhile, in order to achieve the above object, an imaging apparatus according to another aspect of the present invention has a front Stories solid-state imaging element and imaging means for forming an image of a subject with respect to an imaging surface of the solid-state imaging device, the A separated image information generating unit that generates separated image information separated for each of the plurality of divided regions based on a signal output from the solid-state imaging device; and adding the separated image information for each corresponding pixel. Captured image information generating means for generating captured image information, focus control means for performing focus control based on the separated image information or the captured image information when performing imaging using the solid-state imaging device, and the imaging Storage unit for storing the separated image information and the captured image information.

According to the imaging apparatus, a subject image is formed by the imaging means with respect to the imaging surface of the solid-state imaging device.

  Here, in the present invention, the separated image information generation unit generates separated image information separated for each of the plurality of divided regions based on the signal output from the solid-state imaging device, and also the captured image information. The generation means generates the captured image information by adding the separated image information for each corresponding pixel.

  In the present invention, when performing imaging using the solid-state imaging device, the focusing control unit performs focusing control based on the separated image information or the captured image information, and when performing the imaging, The separated image information and the captured image information are stored by a storage unit.

Thus, according to the photographing apparatus, on the basis of the signal output from the solid-state image pickup device, and generates a separation image information separated for each divided region of the light receiving portion of each light receiving element of the solid-state imaging device In addition, when the captured image information is generated by adding the separated image information for each corresponding pixel, and the photographing using the solid-state imaging device is performed, focusing control is performed based on the separated image information or the captured image information. On the other hand, since the separated image information and the photographed image information are stored when the photographing is performed, the processing relating to focusing can be performed with high accuracy by using these image information.

  The storage means includes a RAM (Random Access Memory), an EEPROM (Electrically Erasable and Programmable Read Only Memory), a semiconductor storage element such as a flash EEPROM (Flash EEPROM), an xD picture card (registered trademark), a flexible disk, etc. A portable recording medium, a fixed recording medium such as a hard disk, and the like are included.

Meanwhile, in order to achieve the above object, another aspect by the photographing apparatus of the present invention, the a solid-state imaging device, an imaging means for forming an image of a subject with respect to an imaging surface of the solid-state imaging device, the A separated image information generating unit configured to generate separated image information separated for each of the plurality of divided regions based on a signal output from the solid-state imaging device by the first output; and the second from the solid-state imaging device. Based on the separated image information or the photographed image information, when photographing using the photographed image information generating means for generating photographed image information indicating the photographed image based on the signal output by Focusing control means for performing focusing control, and storage means for storing the separated image information and the captured image information when performing the shooting.

According to the imaging apparatus, a subject image is formed by the imaging means with respect to the imaging surface of the solid-state imaging device.

  Here, in the present invention, the separated image information generation unit generates the separated image information separated for each of the plurality of divided regions based on the signal output from the solid-state imaging device by the first output. At the same time, the photographed image information generating means generates photographed image information indicating a photographed image based on the signal output from the solid-state imaging device by the second output.

  In the present invention, when performing imaging using the solid-state imaging device, the focusing control unit performs focusing control based on the separated image information or the captured image information, and when performing the imaging, The separated image information and the captured image information are stored by a storage unit.

Thus, according to the photographing apparatus, from said solid-state image pickup device on the basis of the signal output by the first output, isolated separated for each divided region of the light receiving portion of each light receiving element of the solid-state imaging device When generating image information and generating captured image information indicating a captured image based on a signal output by the second output from the solid-state imaging device, and performing imaging using the solid-state imaging device, the separated image While focusing control is performed based on the information or the captured image information, the separated image information and the captured image information are stored when performing the capturing. Can be performed with high accuracy.

  The storage means includes a semiconductor storage element such as a RAM, an EEPROM, and a flash EEPROM, a portable recording medium such as an xD picture card (registered trademark) and a flexible disk, and a fixed recording medium such as a hard disk.

The invention according to claim 1 is a separated image information generating unit that generates separated image information separated for each of the plurality of divided regions based on a signal output from the solid-state imaging device, and the separation Captured image information generating means for generating captured image information by adding image information and image information from the light receiving unit provided in the central part for each corresponding pixel, generated separated image information, and generated captured image A storage unit for storing information; a deriving unit for deriving a shift amount of the subject image for each of the light receiving elements of the solid-state imaging device based on the separated image information stored in the storage unit; and the deriving unit Based on the shift amount for each light receiving element obtained by the above, image processing for increasing the blur amount as the shift amount increases is performed on the captured image information stored in the storage unit. Further comprises an image processing means. Thereby, the image processing can be performed with high accuracy.

  According to the present invention, an effect that processing related to focusing can be performed with high accuracy is obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a digital electronic still camera (hereinafter referred to as “digital camera”) that captures a still image will be described.

[First Embodiment]
First, with reference to FIG. 1, the structure of the main part of the electrical system of the digital camera 10 according to the present embodiment will be described.

  As shown in the figure, the digital camera 10 according to the present embodiment is provided with an optical unit 22 including a lens for forming a subject image, and disposed behind the optical axis of the lens. A charge-coupled device (hereinafter referred to as “CCD”) 24 and an analog signal processing unit 26 that performs various analog signal processing on the input analog signal are configured.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 28 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 30.

  The digital signal processing unit 30 has a built-in line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of the memory 48 described later.

  The output terminal of the CCD 24 is connected to the input terminal of the analog signal processing unit 26, the output terminal of the analog signal processing unit 26 is connected to the input terminal of the ADC 28, and the output terminal of the ADC 28 is connected to the input terminal of the digital signal processing unit 30. . Accordingly, the analog signal indicating the subject image output from the CCD 24 is subjected to predetermined analog signal processing by the analog signal processing unit 26, converted into digital image data by the ADC 28, and then input to the digital signal processing unit 30.

  On the other hand, the digital camera 10 generates a liquid crystal display (hereinafter referred to as “LCD”) 38 that displays a captured subject image, a menu screen, and the like, and a signal for causing the LCD 38 to display the subject image, the menu screen, and the like. The LCD interface 36 supplied to the LCD 38, the CPU (central processing unit) 40 that controls the operation of the entire digital camera 10, the memory 48 that temporarily stores digital image data obtained by photographing, and the memory 48 And a memory interface 46 for controlling access.

  Further, the digital camera 10 includes an external memory interface 50 for enabling the portable memory card 52 to be accessed by the digital camera 10, and a compression / decompression processing circuit 54 for performing compression processing and decompression processing on the digital image data. It is configured to include.

  In the digital camera 10 of the present embodiment, a flash memory is used as the memory 48 and an xD picture card (registered trademark) is used as the memory card 52. However, the present invention is not limited to this. Needless to say.

  The digital signal processing unit 30, the LCD interface 36, the CPU 40, the memory interface 46, the external memory interface 50, and the compression / decompression processing circuit 54 are connected to each other via a system bus BUS. Therefore, the CPU 40 controls the operation of the digital signal processing unit 30 and the compression / decompression processing circuit 54, displays various information via the LCD interface 36 to the LCD 38, and the memory interface 46 or the external memory interface to the memory 48 and the memory card 52. 50 can be accessed each.

  On the other hand, the digital camera 10 includes a timing generator 32 that mainly generates a timing signal (pulse signal) for driving the CCD 24 and supplies the timing signal to the CCD 24. The CPU 40 drives the CCD 24 via the timing generator 32. Be controlled.

  Further, the digital camera 10 is provided with a motor drive unit 34, and driving of a focus adjustment motor, a zoom motor, and an aperture drive motor (not shown) provided in the optical unit 22 is also controlled by the CPU 40 via the motor drive unit 34. The

  That is, the lens according to the present embodiment has a plurality of lenses, is configured as a zoom lens system that can change (magnify) the focal length, and includes a lens driving mechanism (not shown). The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor, and these motors are each driven by a drive signal supplied from the motor drive unit 34 under the control of the CPU 40.

  Further, the digital camera 10 has a release switch (so-called shutter) that is pressed when performing shooting, a power switch that is operated when switching on / off the power of the digital camera 10, and a mode for performing shooting. A mode switch that is operated when setting any one of the shooting mode and the reproduction mode that reproduces the subject image on the LCD 38, a menu switch that is pressed when displaying the menu screen on the LCD 38, and so on. The operation unit 56 is configured to include various switches such as a determination switch that is pressed when confirming the operation content, and a cancel switch that is pressed when canceling the previous operation content. These operation units 56 are connected to the CPU 40. Therefore, the CPU 40 can always grasp the operation state of the operation unit 56.

  Note that the release switch of the digital camera 10 according to the present embodiment is in a state where it is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and a state where it is pressed down to a final pressed position beyond the intermediate position. (Hereinafter, referred to as a “fully pressed state”) is configured to be capable of detecting a two-stage pressing operation.

  In the digital camera 10, the AE (Automatic Exposure) function is activated by setting the release switch halfway, the AF function is activated after the exposure state (shutter speed, aperture state) is set. Focusing control is performed, and then exposure (photographing) is performed when the button is fully pressed.

  The digital camera 10 has a strobe 44 that emits light to irradiate the subject as necessary at the time of shooting, and is interposed between the strobe 44 and the CPU 40, and power for causing the strobe 44 to emit light under the control of the CPU 40. And a charging unit 42 for charging the battery. Further, the strobe 44 is also connected to the CPU 40, and the light emission of the strobe 44 is controlled by the CPU 40.

  Next, the configuration of the CCD 24 according to the present embodiment will be described with reference to FIGS. 2 is a plan view showing the pixel structure of the CCD 24, and FIG. 3 is a plan view showing the overall structure of the CCD 24. As shown in FIG.

  As shown in FIG. 2, the CCD 24 according to the present embodiment includes a plurality of light receiving elements 60 (10 million in the present embodiment) arranged in a matrix, each having a light receiving portion 62 that constitutes a pixel. Each light receiving part 62 in each light receiving element 60 is equally divided into two divided regions of a first light receiving part 62A and a second light receiving part 62B.

  The CCD 24 is provided with a plurality of microlenses 64 that correspond to the light receiving elements 60 on a one-to-one basis and that form subject images on the corresponding light receiving elements 60.

  Although illustration is omitted in FIG. 2 to avoid complications, a color filter layer of a corresponding color, a protective film for protecting the color filter layer, and the like are formed between the microlens 64 and the light receiving element 60. Has been.

  Further, as shown in the figure, in the CCD 24 according to the present embodiment, each light receiving element 60 has a honeycomb structure. As a result, the pixel pitch can be reduced and the area per pixel can be increased as compared with a conventional true pixel array structure.

  On the other hand, as shown in FIG. 3, the CCD 24 according to the present embodiment has each light receiving element 60 in the imaging region 70 near the lower end of the imaging region 70 in which the plurality of light receiving elements 60 are arranged in a matrix. A horizontal transfer path 72 that receives the photoelectrically converted signal charges line by line and outputs them to the output amplifier 74 is provided. Here, the output amplifier 74 converts the signal charge of each pixel transferred from the horizontal transfer path 72 into a voltage signal.

  Although not shown in order to avoid complications, the CCD 24 according to the present embodiment receives signal charges photoelectrically converted in the respective light receiving elements 60 in the imaging region 70 and sequentially toward the horizontal transfer path 72. A vertical transfer path for transfer is provided.

  In the CCD 24 according to the present embodiment, in each light receiving element 60, the signal charge accumulated by the first light receiving unit 62A is transferred to the second light receiving unit 62B, whereby the signal accumulated in the second light receiving unit 62B. An addition transfer mode in which the signal charge accumulated in the first light receiving unit 62A is added to the charge, then transferred to the corresponding vertical transfer path and transferred to the horizontal transfer path 72, and the signal accumulated in the first light receiving unit 62A Two operation modes of an individual transfer mode for transferring the charge and the signal charge accumulated in the second light receiving unit 62B individually to the horizontal transfer path 72 via the corresponding vertical transfer paths are provided for the pulse signal input from the outside. It can be selectively applied according to the type. Hereinafter, a pulse signal for operating the CCD 24 in the addition transfer mode is referred to as “addition transfer pulse signal”, and a pulse signal for operating the CCD 24 in the individual transfer mode is referred to as “individual transfer pulse signal”.

  In the digital camera 10 according to the present embodiment, the addition transfer pulse signal or the individual transfer pulse signal can be selectively output to the CCD 24 by the timing generator 32 under the control of the CPU 40.

  The digital camera 10 according to the present embodiment has a predetermined focusing target area (as an example, based on digital image data obtained in a state where the CCD 24 is operated in the addition transfer mode as an AF function. The optical unit generates a focus evaluation value (contrast evaluation value) by extracting and accumulating high-frequency components from luminance information indicated by the digital image data corresponding to a divided area including the center of the imaging area by the CCD 24). 22 by a so-called hill-climbing control method in which the focus lens provided in 22 is moved in the optical axis direction, the position of the focus lens that maximizes the focus evaluation value is specified, and the focus lens is positioned at the position. A hill-climbing focusing function that performs AF control, and a digital image obtained with the CCD 24 operating in the individual transfer mode Based on the image data, the amount of deviation of the subject image is derived for each pixel in the focus target area, and the focus lens is moved to a position corresponding to the amount of deviation, so that AF control is performed by a so-called phase difference AF method. Any one of the phase difference focusing functions can be selectively applied.

  In the digital camera 10 according to the present embodiment, which focusing function is applied is set in advance on the menu screen. However, the present invention is not limited to this, and a switch for setting the focusing function is used. Needless to say, other forms such as a form set by the switch can be used.

  Next, an overall operation at the time of shooting of the digital camera 10 according to the present embodiment will be briefly described. Here, a case where the hill climbing focusing function is set as the focusing function will be described as an example.

  First, the CCD 24 performs imaging through the optical unit 22 and sequentially outputs analog signals for R (red), G (green), and B (blue) indicating the subject image to the analog signal processing unit 26. At this time, the CCD 24 operates in the addition transfer mode, and an analog signal in a state where the signal charge accumulated in the first light receiving unit 62A and the signal charge accumulated in the second light receiving unit 62B for each light receiving element 60 are added is an analog signal. The signals are sequentially output to the signal processing unit 26.

  The analog signal processing unit 26 performs analog signal processing such as correlated double sampling processing on the analog signal input from the CCD 24 and sequentially outputs the analog signal to the ADC 28.

  The ADC 28 converts the R, G, and B analog signals input from the analog signal processing unit 26 into R, G, and B signals (digital image data) each having a predetermined number of bits, and sequentially converts them to the digital signal processing unit 30. Output. The digital signal processing unit 30 accumulates digital image data sequentially input from the ADC 28 in a built-in line buffer and temporarily stores the digital image data directly in a predetermined area of the memory 48.

  The digital image data stored in a predetermined area of the memory 48 is read out by the digital signal processing unit 30 according to the control by the CPU 40, and is subjected to white gain by applying a digital gain for each of R, G, and B according to a predetermined physical quantity. In addition to performing balance adjustment, digital image data having a predetermined number of bits is generated by performing gamma processing and sharpness processing.

  The digital signal processing unit 30 performs YC signal processing on the generated digital image data to generate a luminance signal Y and chroma signals Cr and Cb (hereinafter referred to as “YC signal”), and the YC signal is stored in the memory 48. Is stored in an area different from the predetermined area.

  The LCD 38 is configured to display a moving image (through image) obtained by continuous imaging by the CCD 24 and can be used as a finder. When the LCD 38 is used as a finder, the LCD 38 is generated. The YC signals thus output are sequentially output to the LCD 38 via the LCD interface 36. As a result, a through image is displayed on the LCD 38.

  Here, at the timing when the release switch is half-pressed by the user, after the AE function is activated and the exposure state is set as described above, the above-described hill-climbing focusing function is activated and the focus control is performed, and then, continuously. When the YC signal stored in the memory 48 at that time is fully pressed, the compression / decompression processing circuit 54 compresses the YC signal in a predetermined compression format (JPEG format in the present embodiment), and then the external memory. Shooting is performed by recording an electronic file (image file) in the memory card 52 via the interface 50.

  Next, with reference to FIG. 4, an operation at the time of photographing with the digital camera 10 when the phase difference focusing function is set will be described. FIG. 4 is a flowchart showing the flow of processing of the shooting processing program executed by the CPU 40 when the phase difference focusing function is set as the focusing function and the shooting mode is set. The program is stored in a predetermined area of the memory 48 in advance.

  First, in step 100 in the figure, the process waits until the release switch is half-pressed, and in the next step 102, the timing generator 32 is controlled so that the pulse signal input to the CCD 24 becomes the individual transfer pulse signal. As a result, the CCD 24 is set to operate in the individual transfer mode, and in the next step 104, after the AE function is executed as described above, the phase difference focusing function described above is executed.

  At this time, since the CCD 24 operates in the individual transfer mode, the signal charge accumulated by the first light receiving unit 62A and the signal charge accumulated by the second light receiving unit 62B are individually output for each of the light receiving elements 60. In the phase difference focusing function, focusing control by the phase difference AF method described above is performed using each digital image data obtained based on these signal charges.

  Further, in the AE function executed by the processing of this step 104, digital image data (hereinafter referred to as “first image data”) based on the signal charges accumulated by the first light receiving unit 62A and the second light receiving unit 62B. The exposure state may be set based on the brightness of the subject obtained using at least one of digital image data (hereinafter referred to as “second image data”) based on the signal charge accumulated by the In the digital camera 10 according to the embodiment, the exposure state is set based on the brightness of the subject indicated by the first image data.

  In the next step 106, the timing generator 32 is controlled so that the pulse signal input to the CCD 24 becomes the pulse signal for addition transfer, so that the CCD 24 is set to operate in the addition transfer mode. Then, it is determined whether or not the release switch has been fully pressed. If the determination is affirmative, the process proceeds to step 112. If the determination is negative, the process proceeds to step 110.

  In step 110, it is determined whether or not the release switch has been released by determining whether or not the release switch has been returned to the position where the release switch has not been pressed. On the other hand, if the determination is negative, the process returns to step 102.

  On the other hand, in step 112, photographing is performed as described above (digital image data stored in the memory card 52 by the photographing is hereinafter referred to as “photographed image data”), and in the next step 114, the processing of step 102 is performed. Similarly to the above, the CCD 24 is set to operate in the individual transfer mode.

  In the next step 116, the first image data and the second image data obtained at this time are stored in the memory card 52 in association with the photographed image data stored by the process of step 112, and then the photographing process program is executed. finish. Note that the two digital image data stored in the memory card 52 by the processing in step 116 is hereinafter referred to as “separated image data”.

  Next, referring to FIG. 5, an image conversion process is performed on the photographed image data, in which an image other than the main subject in the subject indicated by the photographed image data is compared with the image conversion processing so far. The operation of the digital camera 10 at the time of performing will be described. FIG. 5 is a flowchart showing the flow of the image conversion processing program executed by the CPU 40 when an instruction to execute the image conversion processing is input by the user. The program is also stored in a predetermined area of the memory 48 in advance. It is remembered. Here, a case will be described in which captured image data to be processed (hereinafter referred to as “processed captured image data”) is designated in advance by the user in order to avoid complications.

  First, in step 200 in the figure, the processing target captured image data and the separated image data corresponding to the processing target captured image data are read from the memory card 52, and in the next step 202, for each pixel in the separated image data, A shift amount of the subject image indicated by the separated image data is calculated. Note that the method for calculating the amount of deviation is the same as the method for calculating the amount of deviation in the conventionally known phase difference AF method, and thus description thereof is omitted here.

  In the next step 204, a blur amount is derived for each pixel so that the deviation amount calculated by the processing in step 202 increases, and in the next step 206, the above-described blur image is obtained for the processing target captured image data. The blurring process using the corresponding blur amount (blur amount) obtained by the process of step 204 is executed for each pixel, and then the image conversion processing program is terminated.

  In the digital camera 10 according to the present embodiment, as the blurring process, a process of applying a low pass filter (Low Pass Filter) to each pixel with an intensity corresponding to the corresponding blur amount is applied. The blurring process is performed in order from the pixel with the smallest deviation amount. At this time, pixels that have already been subjected to the blurring process are excluded from the peripheral pixels used in the low-pass filter. As a result, it is possible to greatly change the intensity of blurring at the boundary between the main subject and the background portion. As a result, it is possible to perform processing for blurring an image other than the main subject with high accuracy.

  As described above, in the digital camera 10 according to the present embodiment, the blurring process is executed by the low-pass filter. However, the form of the blurring process is not limited to this, and the intensity can be set for each pixel. It goes without saying that other blurring processes may be applied.

  As described above in detail, in the solid-state imaging device (here, the CCD 24) according to the present embodiment, each is arranged in a matrix, and the light receiving unit is divided into a plurality of (here, two) pixels in units of pixels. A plurality of light receiving elements that are equally divided into regions, a plurality of microlenses that are respectively provided in a one-to-one correspondence with the plurality of light receiving elements, and that form a subject image on the corresponding light receiving elements; Since the output means (here, the horizontal transfer path 72 and the output amplifier 74) that outputs a signal indicating the amount of received light obtained by the light receiving element is provided, the processing related to focusing can be performed with high accuracy.

  Further, in the solid-state imaging device according to the present embodiment, the plurality of light receiving elements have the light receiving unit equally divided in the horizontal direction in units of pixels, so that the focus control can be performed with high accuracy on the subject in the vertical direction. It can be carried out.

  Further, in the solid-state imaging device according to the present embodiment, since the plurality of light receiving elements have a honeycomb structure, compared to a case where the plurality of light receiving elements have a true pixel array structure, more pixels are provided. As a result of increasing the area of the light receiving portion, it is possible to improve sensitivity characteristics and saturation characteristics. On the other hand, it is possible to further reduce the pixel pitch, thereby increasing the resolution.

  Furthermore, in the solid-state imaging device according to the present embodiment, for each of the plurality of light receiving elements, a signal indicating the amount of received light obtained by each of the plurality of divided regions is output in a state of being separated for each divided region. Since the second output (here, the output in the addition transfer mode) that is output in addition to the first output (here, the output in the individual transfer mode) is selectively performed, As a result of eliminating the need to provide an external means for adding the signal indicating the amount of received light, the solid-state imaging device can be used more easily.

  On the other hand, in the photographing apparatus according to the present embodiment (here, the digital camera 10), based on the signal output from the solid-state image sensor by the first output, the light-receiving unit in each light-receiving element of the solid-state image sensor The separated image information (here, separated image data) separated for each divided region is generated, and the photographed image information (here, the photographed image) indicating the photographed image based on the signal output from the solid-state imaging device by the second output. , Captured image data), and when performing imaging using the solid-state imaging device, while performing focusing control based on the separated image information or the captured image information, Since the information and the photographed image information are stored, the processing relating to focusing can be performed with high accuracy by using these image information.

  Further, in the photographing apparatus according to the present embodiment, based on the separated image information, a deviation amount of the subject image is derived for each of the light receiving elements of the solid-state imaging element, and the derived deviation amount for each light receiving element is obtained. Based on this, since the image processing for increasing the blurring amount as the shift amount increases is performed on the captured image information, the image processing can be performed with high accuracy.

[Second Embodiment]
In the first embodiment, as the solid-state imaging device, for each light receiving element 60, a signal indicating the amount of received light obtained by each of the plurality of divided regions is output in a state of being separated for each divided region. In the second embodiment, the example having the function of selectively performing the second output that is output in combination with the output of the output has been described. However, the second embodiment does not have this function. An example of the case where the above is applied will be described. Since the configuration of the digital camera 10 according to the present embodiment is the same as that according to the first embodiment except for the CCD 24, the configuration of the CCD 24 will be described below.

  In the CCD 24 according to the second embodiment, the pixel structure and the main part configuration are the same as those of the CCD 24 according to the first embodiment (see FIGS. 2 and 3). The difference is that only the individual transfer mode is provided.

  In other words, in the CCD 24 according to the second embodiment, in each light receiving element 60, the signal charges accumulated in the first light receiving part 62A and the signal charges accumulated in the second light receiving part 62B are individually corresponding to the vertical. Only the individual transfer mode for transferring to the horizontal transfer path 72 via the transfer path is applicable.

  Next, with reference to FIG. 6, the operation at the time of shooting of the digital camera 10 according to the second embodiment when the phase difference focusing function is set will be described. FIG. 6 is a flowchart showing a flow of processing of the shooting processing program executed by the CPU 40 when the phase difference focusing function is set as the focusing function and the shooting mode is set. The program is stored in a predetermined area of the memory 48 in advance.

  First, in step 300 in the figure, the process waits until the release switch is half-pressed, and in the next step 302, the phase difference focusing function is executed after the AE function is executed.

  At this time, since the CCD 24 operates in the individual transfer mode, the signal charge accumulated by the first light receiving unit 62A and the signal charge accumulated by the second light receiving unit 62B are individually output for each of the light receiving elements 60. In the phase difference focusing function, focusing control by the phase difference AF method described above is performed using each digital image data (separated image data) obtained based on these signal charges.

  In the AE function executed by the processing of step 302, the first image data based on the signal charges accumulated by the first light receiving unit 62A and the second image based on the signal charges accumulated by the second light receiving unit 62B. The exposure state may be set based on the brightness of the subject obtained using at least one of the data, but in the digital camera 10 according to the second embodiment, the brightness of the subject indicated by the first image data. The exposure state is set based on the above.

  In the next step 304, it is determined whether or not the release switch has been fully pressed. If the determination is affirmative, the process proceeds to step 308. If the determination is negative, the process proceeds to step 306. .

  In step 306, it is determined whether or not the release switch pressing operation has been released by determining whether or not the release switch has been returned to the position where the release switch has not been pressed. On the other hand, if the determination is negative, the process returns to step 302.

  On the other hand, in step 308, the captured image data is derived by adding the first image data and the second image data for each corresponding pixel, and in the next step 310, the captured image data derived by the processing in step 308 is performed. Is stored in the memory card 52 to take a picture.

  In the next step 312, the first image data and the second image data are stored in the memory card 52 in association with the photographed image data stored by the process in step 310, and then the photographing process program is terminated.

  When the hill-climbing focusing function is set as the focusing function, the operation at the time of shooting of the digital camera 10 according to the second embodiment is the above-described shooting processing program when the AE function and the AF function are used. This is the same as the operation of the digital camera 10 according to the photographing processing program except that the AE control and the hill-climbing focusing control are performed using the photographed image data obtained by the processing similar to the processing in step 308.

  Also in the digital camera 10 according to the second embodiment, the image conversion processing program (see FIG. 5) according to the first embodiment is executed.

  As described above in detail, in the imaging apparatus (here, the digital camera 10) according to the present embodiment, each of the solid-state imaging elements is based on the signal output from the solid-state imaging element (here, the CCD 24). In addition to generating separated image information (here, separated image data) separated for each divided region of the light receiving unit in the light receiving element, and adding the separated image information for each corresponding pixel, the captured image information (here, When the photographing is performed using the solid-state image sensor, the focus control is performed based on the separated image information or the photographed image information, while the separated image information is obtained when the photographing is performed. In addition, since the captured image information is stored, the processing relating to focusing can be performed with high accuracy by using the image information.

  Further, in the photographing apparatus according to the present embodiment, based on the separated image information, a deviation amount of the subject image is derived for each of the light receiving elements of the solid-state imaging element, and the derived deviation amount for each light receiving element is obtained. Based on this, since the image processing for increasing the blurring amount as the shift amount increases is performed on the captured image information, the image processing can be performed with high accuracy.

  In each of the above embodiments, the pixel structure of the solid-state image sensor shown in FIG. 2, that is, each light-receiving element 60 is obtained by equally dividing the light-receiving unit 62 in the horizontal direction in units of pixels. However, the present invention is not limited to this, and as an example, as shown in FIG. 7A, each light receiving element 60 has a light receiving portion 62 in a vertical direction in units of pixels. As shown in FIG. 7B, each light receiving element 60 is divided into light receiving portions 62 in units of pixels, as shown in FIG. 7B, which are equally divided (the first light receiving portion 62C and the second light receiving portion 62D in the figure). Are equally divided with respect to the oblique direction (the first light receiving portion 62E and the second light receiving portion 62F in the same figure), and as shown in FIG. 7C, each light receiving element 60 has a pixel unit. With the light receiving unit 62 in the horizontal, vertical and diagonal directions As shown in FIG. 7 (d), the light receiving parts are equally divided (in the figure, the first light receiving part 62G, the second light receiving part 62H, the third light receiving part 62I, the fourth light receiving part 62J). Each of the elements 60 is provided with a light receiving portion for a lens (in the figure, the light receiving portion 62K) having an F value of a predetermined value (for example, F5.6) or less at the center of the light receiving portion 62. It may be a combination of structures.

  In each light receiving element 60, when the light receiving unit 62 is evenly divided in the vertical direction in units of pixels, it is possible to perform focusing control with high accuracy for a lateral subject. In addition, when each light receiving element 60 has a light receiving unit 62 that is evenly divided in an oblique direction in units of pixels, focus control can be performed with high accuracy on both a vertical subject and a horizontal subject. As a result, the pitch between the corresponding divided regions can be made narrower, and as a result, focusing control can be performed with higher accuracy.

  Further, when each light receiving element 60 is provided with a light receiving portion for a lens having an F value equal to or less than a predetermined value at the center portion, the received light amount obtained by the light receiving portion and a plurality of divided regions in the light receiving portion 62 By adding the received light amounts obtained by the above, it is possible to expand the dynamic range when photographing with the solid-state imaging device.

  In each of the above embodiments, the case where the solid-state imaging device of the present invention is applied to a CCD has been described. However, the present invention is not limited to this, and is applied to, for example, a CMOS image sensor. You can also. Also in this case, the same effects as those of the above embodiments can be obtained.

  In each of the above embodiments, the case where the number of divided regions of the light receiving unit 62 in each light receiving element 60 is two has been described. However, the present invention is not limited to this, and the number of divided regions is three. It is good also as a form made into the above.

  Further, although cases have been described with the above embodiments where the present invention is applied to a digital camera, the present invention is not limited to this, and other devices having a photographing function, such as a mobile phone and a PDA, for example. It can also be set as the form applied to. Also in this case, the same effects as those of the above embodiments can be obtained.

  In addition, the configurations of the digital camera and the CCD according to each of the above-described embodiments (see FIGS. 1 to 3 and 7) are merely examples, and it goes without saying that they can be changed as appropriate without departing from the gist of the present invention. Yes.

  Furthermore, the processing flow of the various processing programs described in the above embodiments (see FIGS. 4 to 6) is also an example, and the processing order of each step can be changed without departing from the gist of the present invention. It goes without saying that processing contents can be changed, unnecessary steps can be deleted, new steps can be added, and the like.

It is a block diagram which shows the principal part structure of the electric system of the digital camera which concerns on embodiment. It is a top view which shows the principal part structure (pixel structure) of CCD which concerns on embodiment. It is a top view which shows the principal part structure (whole structure) of CCD which concerns on embodiment. It is a flowchart which shows the flow of a process of the imaging | photography processing program which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the image conversion processing program which concerns on embodiment. It is a flowchart which shows the flow of a process of the imaging | photography processing program which concerns on 2nd Embodiment. It is a top view which shows the structural example of the other pixel structure of CCD which concerns on embodiment. It is a side view for explaining the principle of the phase difference AF method.

Explanation of symbols

10 Digital camera 22 Optical unit (imaging means)
24 CCD (solid-state image sensor)
40 CPU (captured image information generation means, focus control means, derivation means, image processing means)
52 Memory card (memory means)
60 light receiving element 62 light receiving portion 62A first light receiving portion 62B second light receiving portion 62C first light receiving portion 64D second light receiving portion 62E first light receiving portion 62F second light receiving portion 62G first light receiving portion 62H second light receiving portion 62I third light receiving portion Part 62J fourth light receiving part 62K light receiving part 64 micro lens 72 horizontal transfer path (output means)
74 Output amplifier (output means)

Claims (3)

Each of the light receiving parts is arranged in a matrix, and the light receiving part is equally divided into a plurality of divided areas with respect to at least one of the horizontal direction, the vertical direction, and the oblique direction , and each of the center parts of the light receiving parts. forming an object image into a plurality of light-receiving element that F values are light-receiving unit for a predetermined value or more lenses are provided, it is provided corresponding 1-one to each of the plurality of light receiving elements, the corresponding light-receiving element and the solid-state image sensor having a plurality of micro lenses, and the output means to output a signal indicating the amount of received light obtained by the plurality of light receiving elements for the image,
Separated image information generating means for generating separated image information separated for each of the plurality of divided regions based on a signal output from the solid-state imaging device;
Photographic image information generating means for generating photographic image information by adding the separated image information and the image information by the light receiving unit provided in the central portion for each corresponding pixel;
Storage means for storing the generated separated image information and the generated captured image information;
Derivation means for deriving a shift amount of the subject image for each of the light receiving elements of the solid-state imaging device based on the separated image information stored in the storage means;
Based on the shift amount for each light receiving element obtained by the derivation unit, the image processing unit performs image processing for increasing the blur amount as the shift amount increases with respect to the captured image information stored in the storage unit. When,
An imaging device including: Wherein the plurality of light receiving elements, photographing apparatus according to claim 1, wherein there is a honeycomb structure. The output means adds, for each of the plurality of light receiving elements, a first output that outputs a signal indicating the amount of received light obtained by each of the plurality of divided regions in a state of being separated for each divided region. The imaging device according to claim 1, wherein the second output that is output in a state is selectively performed.

Images