JP5187039B2 - Solid-state imaging device and electronic camera using the same - Google Patents

Description

  The present invention relates to a solid-state imaging device and an electronic camera using the same.

  In recent years, electronic cameras such as video cameras and electronic still cameras having an AF (autofocus) function (automatic focus adjustment function) have been widely used. In these cameras, a solid-state imaging device such as a CCD type or a CMOS type is used. In these solid-state imaging devices, a plurality of pixels having a photoelectric conversion unit that generates a signal charge according to the amount of incident light is arranged in a two-dimensional matrix.

  Conventionally, in such an electronic camera, when a special focus detection element is not provided separately from the solid-state image sensor used for imaging, AF is realized using an image signal from the solid-state image sensor as a focus detection method. Contrast method is used. The contrast method is a method in which the lens is moved little by little to obtain the contrast from the image signal, and the lens is moved and focused so that the contrast is maximized. In this case, the contrast is maximized. As a control method, a mountain climbing method or the like is used. Therefore, the contrast method cannot be focused at high speed in principle.

  Patent Document 1 discloses a camera that displays a live view display on a display unit such as a liquid crystal panel disposed on the back surface of the camera, etc., in an electronic camera employing such a contrast method. The live view display is an image display based on an image signal obtained from the solid-state imaging device, and is very convenient for the user to check the shooting situation such as framing of the subject before the main shooting.

  And in patent document 1, when the brightness | luminance of a to-be-photographed object is low brightness, the live view read-out mode and the addition read-out mode are switched alternately for every frame, and the read-out operation of the image signal from a CCD color area sensor is performed, The display unit displays an image based on the live view image signal read out during the live view readout mode period, and the AF control unit performs AF control using a contrast method based on the addition luminance image signal read out during the addition readout mode period. Is disclosed. The live view readout mode is a readout mode in which a charge is read out from a plurality of photoelectric conversion elements arranged in the vertical direction in a CCD color area sensor for each predetermined number of photoelectric conversion elements to generate a live view image signal. It is. In the addition reading mode, charges generated by a plurality of continuous photoelectric conversion elements arranged in the vertical direction or a plurality of continuous photoelectric conversion elements arranged in the horizontal direction of the CCD color area sensor are added. This is a read mode for reading out and generating an added luminance image signal.

  Therefore, in the electronic camera disclosed in Patent Document 1, when the luminance of the subject is reduced, the contrast-based AF is performed based on the added luminance image signal that can obtain a large output even with the same light amount as compared with the normal reading operation. By performing the control, AF control by a stable contrast method can be performed. Even when the luminance of the subject is lowered, the display unit can obtain the color information of the subject by displaying the image based on the live view image signal.

  In the electronic camera disclosed in Patent Document 1, the alternate switching for each frame between the live view readout mode and the addition readout mode is performed only when the subject brightness is low, and the subject brightness is relatively high. This is not the case (FIG. 8 of Patent Document 1).

  By the way, in recent years, a solid-state imaging device has been proposed that adopts a so-called pupil division phase difference method as a focus detection method and can also be used as a focus detection device (for example, Patent Document 2 below). Unlike the contrast method, the pupil division phase difference method does not need to move the lens by trial and error, and thus can be focused at high speed in principle.

In the solid-state imaging device disclosed in Patent Document 2, the focus adjustment state is detected according to the pupil division phase difference method, separately from the imaging pixels that output the imaging signals for forming the image signal indicating the subject image. A plurality of focus detection pixels (also referred to as “AF pixels”) that generate focus detection signals are arranged. In this solid-state imaging device, the AF pixel has a photoelectric conversion unit divided into two. On such a photoelectric conversion unit, microlenses are provided on a one-to-one basis with respect to pixels. The two-divided photoelectric conversion unit is arranged at a position where the microlens is in a substantially imaging relationship (that is, substantially conjugate) with the exit pupil of the imaging lens. Therefore, since the distance between the exit pupil of the imaging lens and the microlens is sufficiently long with respect to the size of the microlens, the two-divided photoelectric conversion unit is disposed at a substantially focal position of the microlens. It will be. From the relationship described above, in each pixel, one part of the photoelectric conversion unit divided into two parts is a part of the exit pupil of the imaging lens and emits a light beam from an area decentered in a predetermined direction from the center of the exit pupil. The light is selectively received and photoelectrically converted. In each AF pixel, the other part of the photoelectric conversion unit divided into two parts selectively receives a light beam from a region that is part of the exit pupil of the imaging lens and decentered in the opposite direction from the center of the exit pupil. And photoelectric conversion.
JP 2006-261929 A JP 2003-244712 A

  In the electronic camera disclosed in Patent Document 1, when the luminance of the subject is low, AF control is performed while the live view display is displayed. Therefore, the user may check the in-focus state on the live view display. Can be very preferable.

  However, since the electronic camera disclosed in Patent Document 1 performs AF control using a contrast method with a slow focusing speed, focus adjustment can completely follow a subject moving at a relatively high speed in a relatively short distance. It was impossible to display live view in the focused state.

  As described above, there has been no electronic camera that can display a live view of a subject moving at a relatively high speed in a relatively short distance in a focused state following the object. However, in an electronic camera, if a subject moving at a relatively high speed at a relatively short distance can be displayed in a live view in a focused state following the object, the convenience for the user is immeasurable.

  The present invention has been made in view of such circumstances, and an electronic camera capable of displaying a live view of a subject moving at a relatively high speed in a relatively short distance in a focused state following the subject. An object of the present invention is to provide a solid-state imaging device.

  Note that Patent Document 2 merely discloses a solid-state imaging device having an AF pixel according to the pupil division phase difference method in addition to the imaging pixel. From such a solid-state imaging device, live view display and the like are disclosed. There is no disclosure or suggestion regarding a method for reading out signals in relation to the above. Further, the alternate switching for each frame between the live view readout mode and the addition readout mode performed in the electronic camera disclosed in Patent Document 1 is a special technique for compensating for the reduction in luminance when the luminance of the subject is low. It is clear that it is an operation. Therefore, even if the contents described in Patent Document 1 are taken into consideration, it is impossible to conceivably switch between different reading modes for each frame when signals are read from the solid-state imaging device disclosed in Patent Document 2.

  In order to solve the above-described problem, the solid-state imaging device according to the first aspect of the present invention includes a plurality of pixels arranged two-dimensionally, each of which is incident light from a subject image formed by an optical system. A plurality of pixels having a photoelectric conversion unit that generates and accumulates corresponding signal charges, and read control means for performing control to read signals from the plurality of pixels so as to perform live view display, and the plurality of pixels include: A plurality of imaging pixels that output an imaging signal for forming an image signal indicating the subject image, and a focus detection signal for detecting a focus adjustment state of the optical system according to a pupil division phase difference method And a plurality of focus detection pixels.

  The solid-state imaging device according to the second aspect of the present invention is a plurality of pixels arranged two-dimensionally, each generating a signal charge corresponding to incident light from a subject image formed by an optical system. A plurality of pixels each having a photoelectric conversion unit to be stored; and a read control unit that performs control to read signals from the plurality of pixels, and the plurality of pixels are configured to form an image signal indicating the subject image. A plurality of image pickup pixels for outputting a signal for use and a plurality of focus detection pixels for outputting a focus detection signal for detecting a focus adjustment state of the optical system according to a pupil division phase difference method, The control means cyclically repeats two or more readout modes for each frame in a predetermined operation mode, and the two or more readout modes read an imaging signal for live view display. A reading mode for live view out, and a read mode for focus detection to read out the focus detection signals, is intended to include.

  A solid-state imaging device according to a third aspect of the present invention is the solid-state imaging device according to the second aspect, wherein the vertical signal line provided corresponding to each column of the plurality of pixels and supplied with the output signal of the pixel in the corresponding column is provided. In addition, in the live view readout mode, pixel signals read out in the column direction are read out.

  In the solid-state imaging device according to the fourth aspect of the present invention, in the first or second aspect, in the focus detection readout mode, the exposure time of each pixel is the same for the pixel from which the signal is to be effectively read out. In addition, an electronic shutter operation is performed at the same timing.

  A solid-state imaging device according to a fifth aspect of the present invention is the solid-state imaging device according to any one of the second to fourth aspects, wherein partial readout for reading out the pixel signals of a partial region is performed in the focus detection readout mode. It is.

  The solid-state imaging device according to a sixth aspect of the present invention is the solid-state imaging device according to any one of the second to fifth aspects, wherein the two or more readout modes are automatic readouts of imaging signals for use in photometric information for automatic exposure. This includes an exposure readout mode.

  The solid-state imaging device according to a seventh aspect of the present invention is the solid-state imaging device according to the sixth aspect, wherein in the automatic exposure readout mode, the exposure time of each pixel has the same length with respect to the pixel from which a signal is to be effectively read. The electronic shutter operation at the same timing is performed.

  According to an eighth aspect of the present invention, in the sixth or seventh aspect, the solid-state imaging device is provided corresponding to each column of the plurality of pixels, and is supplied with an output signal of the pixel in the corresponding column. A signal line is provided, and in the automatic exposure readout mode, horizontal pixel addition is performed by adding and reading out signals of two or more pixels in the row direction.

  The solid-state imaging device according to a ninth aspect of the present invention is the solid-state imaging device according to any one of the sixth to eighth aspects, wherein in the automatic exposure readout mode, the signals of the pixels in two consecutive rows are read regarding the signal readout in the column direction. After reading out, it is repeated that signals of pixels in M rows (M is an even number) are skipped.

  According to a tenth aspect of the present invention, in the ninth aspect, each of the plurality of pixels receives the signal charge from the photoelectric conversion unit of the pixel and converts the signal charge into a voltage. Charge voltage conversion unit, an amplification unit that outputs a signal corresponding to the potential of the charge voltage conversion unit, a charge transfer unit that transfers charges from the photoelectric conversion unit to the charge voltage conversion unit, and a potential of the charge voltage conversion unit A reset unit that resets, and a selection unit that selects the pixel. The plurality of pixels are pixels for each of L pixels (L is an even number of 2 or more) in which the photoelectric conversion units are sequentially arranged in a column direction. A block is formed, and for each pixel block, the L pixels belonging to the pixel block share a set of the charge-voltage conversion unit, the amplification unit, the reset unit, and the selection unit, and M is {L × (2 + N) -2} N is one integer of 0 or more).

  In the solid-state imaging device according to an eleventh aspect of the present invention, in any one of the second to ninth aspects, each of the plurality of pixels receives the signal charge from the photoelectric conversion unit of the pixel, and A charge-voltage converter that converts signal charge into voltage; an amplifier that outputs a signal corresponding to the potential of the charge-voltage converter; a charge transfer unit that transfers charge from the photoelectric converter to the charge-voltage converter; A reset unit that resets the potential of the voltage conversion unit and a selection unit that selects the pixel are included.

  The solid-state imaging device according to a twelfth aspect of the present invention is the solid-state imaging device according to the eleventh aspect, wherein each of the plurality of pixels is L pixels (L is an integer of 2 or more) in which the photoelectric conversion units are sequentially arranged in a column direction. A pixel block is formed, and for each pixel block, the L pixels belonging to the pixel block share a set of the charge-voltage conversion unit, the amplification unit, the reset unit, and the selection unit.

  A solid-state imaging device according to a thirteenth aspect of the present invention is the solid-state imaging device according to any one of the second to twelfth aspects, wherein the plurality of imaging pixels are provided with color filters arranged according to a Bayer array. .

  An electronic camera according to a fourteenth aspect of the present invention includes the solid-state imaging device according to any one of the second to thirteenth aspects and a display unit capable of performing live view display, and in the predetermined operation mode, An automatic focus adjustment of the optical system is performed based on the signal read in the focus detection readout mode while displaying the live view display on the display unit based on the signal read in the live view readout mode. It is.

  An electronic camera according to a fifteenth aspect of the present invention includes the solid-state imaging device according to any one of the sixth to thirteenth aspects and a display unit capable of performing live view display, and in the predetermined operation mode, While displaying the live view display on the display unit based on the signal read in the live view readout mode, the optical system of the optical system according to the pupil division phase difference method based on the signal read in the focus detection readout mode. In addition to performing automatic focus adjustment, automatic exposure control is performed based on signals read in the automatic exposure readout mode.

  According to the present invention, it is possible to provide an electronic camera capable of displaying an object moving at a relatively high speed in a relatively short distance in a live view in a focused state following the object, and a solid-state imaging device used therefor. .

  Hereinafter, a solid-state imaging device according to the present invention and an electronic camera using the same will be described with reference to the drawings.

  [First Embodiment]

  FIG. 1 is a schematic block diagram showing an electronic camera 1 according to the first embodiment of the present invention. A photographing lens 2 is attached to the electronic camera 1. The photographing lens 2 is driven by a lens control unit 2a for focus and diaphragm. In the image space of the photographic lens 2, the imaging surface of the solid-state imaging device 3 is arranged.

  The solid-state imaging device 3 is driven by a command from the imaging control unit 4 and outputs a signal. The signal output from the solid-state imaging device 3 is either an imaging signal for forming an image signal indicating a subject image or a focus detection signal for detecting the focus adjustment state of the photographing lens 2. Some of the imaging signals may be used for automatic exposure photometric information. In any case, the signal is processed through the signal processing unit 5 and the A / D conversion unit 6 and then temporarily stored in the memory 7. The memory 7 is connected to the bus 8. Also connected to the bus 8 are a lens control unit 2a, an imaging control unit 4, a microprocessor 9, a focus calculation unit 10, an exposure calculation unit 14, a recording unit 11, an image compression unit 12, an image processing unit 13, a display control unit 15, and the like. Is done. The display control unit 15 displays a monitor image such as a live view display on a liquid crystal display unit (LCD) 16. The microprocessor 9 is connected to an operation unit 9a such as a release button. A recording medium 11a is detachably attached to the recording unit 11 described above. A solid-state imaging device according to an embodiment of the present invention is configured by the solid-state imaging device 3, the imaging control unit 4, the signal processing unit 5, and the like.

  FIG. 2 is a circuit diagram showing a schematic configuration of the solid-state imaging device 3 in FIG. The solid-state imaging device 3 includes a plurality of pixels 20 arranged in a two-dimensional matrix and a peripheral circuit for outputting a signal from the pixels 20. In FIG. 2, the number of pixels indicates 32 pixels of 8 columns horizontally and 4 rows vertically. However, in the present embodiment, the number of pixels is much larger than that. However, in the present invention, the number of pixels is not particularly limited.

  In the present embodiment, the solid-state imaging device 3 adjusts the focus of the imaging lens 2 according to the pupil division phase difference method and the imaging pixel 20e that outputs an imaging signal for forming an image signal indicating a subject image as pixels. 2 includes focus detection pixels (hereinafter referred to as “AF pixels”) 20a, 20b, 20c, and 20d that output focus detection signals for detecting a state. This is indicated by reference numeral 20 without distinction. The specific circuit configuration and structure will be described later. These pixels 20 output imaging signals or focus detection signals in accordance with peripheral circuit drive signals. In addition, all the pixels 20 are reset at the same time, and the electronic shutter operation is performed with the exposure time having the same length and the same timing. Is also possible.

  The peripheral circuit includes a vertical scanning circuit 21, a horizontal scanning circuit 22, driving signal lines 23 to 27 connected thereto, a vertical signal line 28 for receiving a signal from the pixel 20, and a constant current source connected to the vertical signal line 28. 29, a column amplifier 30, a front switch 31 and a rear switch 32 composed of transistors, a horizontal signal line 33 for receiving a signal output from the column amplifier 30 via the front switch 31 and the rear switch 32, an output amplifier 34, and the like.

  In the present embodiment, the pre-stage switch 31 is provided on a one-to-one basis with respect to the vertical signal line 28 (and thus the column amplifier 30). On the other hand, the post-stage switch 32 is provided for each group of four vertical signal lines 28 in the row direction (that is, for each of the four pre-stage switches). One end of each pre-stage switch 3 is connected to the corresponding column amplifier 30, and the other end of the four pre-stage switches 31 belonging to the same group is commonly connected to one end of the post-stage switch 32 corresponding to the group. The other end of each rear switch 32 is connected to a horizontal signal line 33. The gates of the front-stage switch 31 are connected to corresponding ones in different groups in common and receive the drive signal φH from the horizontal scanning circuit 22. The gates of the respective rear stage switches 32 receive the drive signal φG from the horizontal scanning circuit 22. In the present embodiment, with such a configuration, horizontal pixel addition is performed by adding and reading the signals of the four pixels 20 in the row direction by changing the drive signals φH and φG from the horizontal scanning circuit 22. However, it is also possible to individually read out the pixel signals in the row direction without performing horizontal pixel addition. The number of pixels that can be subjected to horizontal pixel addition can be set to a desired number by changing the above four to a desired number. Needless to say, the circuit configuration capable of selectively performing horizontal pixel addition is not limited to the above-described configuration.

  In the present embodiment, the correlated double sampling circuit (CDS circuit) is provided in the signal processing unit 5 in FIG. 1, and after the signal is output to the outside of the solid-state imaging device 3 via the output amplifier 34. The signal processing unit 5 performs correlated double sampling processing. Needless to say, the CDS circuit may be mounted on the solid-state imaging device 3. When the CDS circuit is mounted on the solid-state imaging device 3, the CDS circuit can be configured using the column amplifier 30.

  Each pixel 20 has the same circuit configuration regardless of which of the pixels 20a, 20b, 20c, 20d, and 20e. FIG. 3 is a circuit diagram showing the pixel 20 of the solid-state imaging device 3 in FIG.

  Each pixel 20 includes a photodiode PD as a photoelectric conversion unit that generates and accumulates signal charges according to incident light, and receives the signal charges and converts the signal charges into voltage as in a general CMOS solid-state imaging device. A floating diffusion FD serving as a charge-voltage converting unit for converting to a voltage, an amplifying transistor AMP serving as an amplifying unit for outputting a signal corresponding to the potential of the floating diffusion FD, and a charge transferring unit configured to transfer charges from the photodiode PD to the floating diffusion FD 3 includes a transfer transistor TX, a reset transistor RES as a reset unit for resetting the potential of the floating diffusion FD, and a selection transistor SEL as a selection unit for selecting the pixel 20, as shown in FIG. Connected That. In the present embodiment, the transistors AMP, TX, RES, and SEL of the pixel 20 are all nMOS transistors. In FIG. 3, Vdd is a power supply voltage.

  The gate of the transfer transistor TX is connected to a control line 24 that supplies a control signal φTX for controlling the transfer transistor TX from the vertical scanning circuit 21 to the transfer transistor TX for each row. A gate of the reset transistor RES is connected to a control line 23 that supplies a control signal φRST for controlling the reset transistor RES from the vertical scanning circuit 21 to the reset transistor RES for each row. The gate of the selection transistor SEL is connected to the control line 25 that supplies the selection transistor SEL with a control signal φSEL for controlling the selection transistor SEL from the vertical scanning circuit 21 for each row.

  The photodiode PD generates a signal charge according to the amount of incident light (subject light). The transfer transistor TX is turned on during the high level period of the transfer pulse (control signal) φTX, and transfers the signal charge accumulated in the photodiode PD to the floating diffusion FD. The reset transistor RES is turned on during a high level period of the reset pulse (control signal) φRST to reset the floating diffusion FD.

  The amplification transistor AMP has a drain connected to the power supply voltage Vdd, a gate connected to the floating diffusion FD, a source connected to the drain of the selection transistor SEL, and a force follower circuit having the constant current source 29 as a load. doing. The amplification transistor AMP outputs a read current to the vertical signal line 28 via the selection transistor SEL according to the voltage value of the floating diffusion FD. The selection transistor SEL is turned on during the high level period of the selection pulse (control signal) φSEL, and connects the source of the amplification transistor AMP to the vertical signal line 28.

  The vertical scanning circuit 21 receives a drive pulse (not shown) from the imaging control unit 4 and outputs a selection pulse φSEL, a reset pulse φRST, and a transfer pulse φTX for each row of the pixels 20. Further, the horizontal scanning circuit 22 receives a driving pulse (not shown) from the imaging control unit 4 and outputs control signals φH1 to φH4, φG1, and φG2.

  FIG. 4 is a schematic plan view schematically showing an effective pixel region of the solid-state imaging device 3 in FIG. In FIG. 4, in order to facilitate understanding, it is assumed that 16 × 16 pixels 20 exist in the effective pixel region. In FIG. 4, the focus detection area is surrounded by a thick line. In the present embodiment, as shown in FIG. 4, the effective pixel area of the solid-state imaging device 3 includes two focus detection areas having a cross shape disposed in the center, and 2 arranged horizontally and extending vertically. There are two focus detection areas and two focus detection areas that are arranged one above the other and extend left and right. As shown in FIG. 4, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined. A plane parallel to the XY plane coincides with the imaging surface (light receiving surface) of the solid-state imaging device 3. The arrangement in the X-axis direction is a row, and the arrangement in the Y-axis direction is a column. Incident light is incident from the front side of the drawing in FIG. These points are the same for the drawings described later.

  In the present embodiment, each pixel 20 is provided with a color filter according to the Bayer arrangement. In FIG. 4, the colors of the color filters provided in the pixel are indicated by symbols R, G, and B. R is red, G is green, and B is blue. If the solid-state imaging device 3 is classified without distinguishing the colors of the color filters provided in the pixel, the solid-state imaging device 3 has one type of imaging pixel 20e and four types of AF pixels 20a, 20b, 20c, and 20d. doing. In FIG. 4, the AF pixels 20 a, 20 b, 20 c, and 20 d are denoted by symbols a, b, c, and d, respectively. Further, none of the symbols a, b, c, and d is attached to the imaging pixel 20e. Therefore, for example, in FIG. 4, “R” means the imaging pixel 20 e provided with the red color filter, and “Ga” means the AF pixel 20 a provided with the green color filter.

  FIG. 5A is a schematic plan view schematically showing the main part of the imaging pixel 20e, and FIG. 5B is a schematic cross-sectional view taken along line X1-X2 in FIG. 5A. The imaging pixel 20e includes a photodiode PD as a photoelectric conversion unit, a microlens 42 formed on-chip on the photodiode PD, and R (red), G (provided on the light incident side of the photodiode PD). A color filter 50 of either green or B (blue). Further, as shown in FIG. 5, a light shielding layer 43 such as a metal layer as a light shielding portion is formed on a substantially focal plane of the microlens 42. The light shielding layer 43 also serves as a wiring layer as necessary. In the light shielding layer 43, a square opening 43a concentric with the optical axis O of the microlens 42 of the imaging pixel 20e is formed in the imaging pixel 20e. The photodiode PD of the pixel 20e has a size that can effectively receive all the light that has passed through the opening 43a. An interlayer insulating film or the like is formed between the light shielding layer 43 and the microlens 42 or between the substrate 44 and the light shielding layer 43.

  In the present embodiment, in the pixel 20e, the opening 43a is formed in the light-shielding layer 43 disposed substantially at the focal plane of the microlens 42, so that the photodiode PD of the pixel 20e has the exit pupil of the photographing lens 2. Light from a region of the exit pupil (corresponding to a projection image by the microlens 42 of the opening 43a) that is not substantially decentered from the center of the light is received and photoelectrically converted.

  FIG. 6A is a schematic plan view schematically showing the main part of the AF pixel 20a, and FIG. 6B is a schematic cross-sectional view taken along line X3-X4 in FIG. 6A. 6, elements that are the same as or correspond to those in FIG. 5 are given the same reference numerals, and redundant descriptions thereof are omitted. This also applies to FIGS. 7 to 9 described later.

  The AF pixel 20a is different from the imaging pixel 20e in that the AF pixel 20a has a square concentric with the optical axis O of the microlens 42 of the AF pixel 20a (same as the opening 43a). The only difference is that a rectangular opening 43b is formed that is exactly half the size of the right square (+ X side). Note that the photodiode PD of the pixel 20a has the same size as the photodiode PD of the pixel 20e. As described above, in this embodiment, the opening 43b is half of the opening 43a. However, the present invention is not limited to this. For example, the opening 43b is a square concentric with the optical axis O of the microlens 42 of the AF pixel 20a. A rectangular opening having a size of about 40% or 60% on the right side (+ X side) of (a square having the same size as the opening 43a) may be used. The aperture 43b of the AF pixel 20a preferably has the same size as an aperture 43c described later of the AF pixel 20b, and an aperture 43d described later of the AF pixel 20c is the same as an aperture 43e described later of the AF pixel 20d. It is preferable to have a size.

  In the pixel 20a, the opening 43b is formed in the light shielding layer 43, so that the photodiode PD of the pixel 20a is substantially decentered in the −X direction from the center of the exit pupil of the photographing lens 2. The light flux from the light is selectively received and photoelectrically converted.

  FIG. 7A is a schematic plan view schematically showing the main part of the AF pixel 20b, and FIG. 7B is a schematic cross-sectional view taken along line X5-X6 in FIG. 7A. The AF pixel 20b is different from the imaging pixel 20e in that the AF pixel 20b has a square concentric with the optical axis O of the microlens 42 of the AF pixel 20b (same as the opening 43a). The only difference is that a rectangular opening 43c is formed that is exactly half the size of the left side (-X side). As a result, the photodiode PD of the pixel 20b selectively receives and photoelectrically converts the light beam from the exit pupil region that is substantially decentered in the + X direction from the center of the exit pupil of the photographic lens 2.

  FIG. 8A is a schematic plan view schematically showing the main part of the AF pixel 20c, and FIG. 8B is a schematic cross-sectional view taken along line Y1-Y2 in FIG. 8A. The AF pixel 20c is different from the imaging pixel 20e in that in the AF pixel 20c, the light shielding layer 43 has a square concentric with the optical axis O of the microlens 42 of the AF pixel 20c (same as the opening 43a). It is only a point where a rectangular opening 43d having a size just half the upper side (+ Y side) is formed. As a result, the photodiode PD of the pixel 20c selectively receives and photoelectrically converts the light beam from the exit pupil region that is substantially decentered in the −Y direction from the center of the exit pupil of the photographic lens 2. .

  FIG. 9A is a schematic plan view schematically showing the main part of the AF pixel 20d, and FIG. 9B is a schematic cross-sectional view taken along line Y3-Y4 in FIG. 9A. The AF pixel 20d is different from the imaging pixel 20e in that the AF pixel 20d has a concentric square (same as the opening 43a) in the light shielding layer 43 with respect to the optical axis O of the microlens 42 of the AF pixel 20d. The only difference is that a rectangular opening 43e is formed that is exactly half the size of the lower half (-Y side) of the size square. As a result, the photodiode PD of the pixel 20d selectively receives and photoelectrically converts the light beam from the exit pupil region that is substantially decentered in the + Y direction from the center of the exit pupil of the photographing lens 2.

  Note that the arrangement of the color filters 50 is not necessarily limited to the Bayer arrangement. Further, even when configured for color imaging, the color filters 50 are not necessarily provided in the AF pixels 20a, 20b, 20c, and 20d.

  FIG. 10 is a timing chart schematically showing a signal readout state from the solid-state imaging device 3 when the electronic camera 1 according to the present embodiment is in a predetermined operation mode. As shown in FIG. 10, the electronic camera 1 according to the present embodiment has a live view readout mode for reading out an imaging signal for live view display from the solid-state imaging device 3 and a focus detection signal from the solid-state imaging device 3. A focus detection readout mode (also referred to as “AF readout mode”) to be read out and an automatic exposure readout mode (also referred to as “AE readout mode”) in which an imaging signal to be used for photometric information for automatic exposure is read out from the solid-state imaging device 3. )) Is repeated cyclically for each frame. For example, the live view readout frame may be about 1/40 second, the AF readout frame may be about 1/100 second, and the AE readout frame may be about 1/200 second. Note that the order of these read modes is not limited to the example shown in FIG. Specific examples of these read modes will be described below.

  Assuming that each pixel 20 is arranged as shown in FIG. 4, in the live view readout mode, for example, a circle mark is attached to the right side in FIG. 4 under the control of the imaging control unit 4. Then, the pixels 20 are thinned out in the column direction, and the first, fourth, seventh, tenth, thirteenth and sixteenth rows are read by skipping every two rows. It is preferable that the number of rows skipped in this way is an even number. This is to maintain Bayer readout. In the live view readout mode, it is preferable to read out the signals of the pixels 20 thinned out in the column direction in order to read out the signals at high speed, but the signals of the pixels 20 in all rows may be read out.

  FIG. 11 shows that when the number of pixels 20 is 4 × 8 as shown in FIG. 2, the first row is read, the second and third rows are skipped, and the fourth row is skipped in the live view readout mode. It is a timing chart which shows the example read. In this example, all pixels in the row direction are read without performing horizontal pixel addition. In this example, an electronic shutter operation using a rolling shutter is performed. In FIG. 11, a period T1 is a selection period for the first row. The exposure time for the first row is from the end point of the period T2 to the start point of the period T3. CDS processing for taking the difference between the signals read in the periods T4 and T5 and the signals read in the periods T6 and T7 is performed by the signal processing unit 5 outside the solid-state imaging device 3. In the period T8 in which the fourth row is selected, the same operation as that in the period T1 is performed on the fourth row.

  In the example shown in FIG. 11, in the live view readout mode, all pixels in the row direction are read out for the readout row as described above. However, in the live view readout mode, only pixels in an arbitrary partial column may be read out regarding the readout row. For example, the pixels in the row direction may be read out every four columns. In this case, the signal can be read out at higher speed. Such readout of pixels in some columns can be realized, for example, by configuring the horizontal scanning circuit 22 using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208685. . Note that, in order to partially read out pixels in some rows in the live view readout mode, the vertical scanning circuit 21 is configured using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208855. Also good.

  In the AF readout mode, if each pixel 20 is arranged as shown in FIG. 4, for example, three focus detection regions extending in the row direction are marked with a circle on the right side in FIG. Read the corresponding 3, 8, 14th lines. In the present embodiment, at this time, all the pixels 20 in the horizontal direction are read for each row. However, it is also possible to read out only the pixels in the column portion corresponding to the focus detection area in the horizontal direction. Here, it is determined from the previous live view image or the like that it is determined that the focus adjustment state of the subject can be detected with higher accuracy by using the signal of the focus detection area extending in the row direction. Below, only the rows corresponding to the three focus detection areas extending in the row direction are read out. However, for example, when it is determined from the previous live view image or the like that the focus adjustment state of the subject can be detected more accurately by using the signal of the focus detection area extending in the column direction, the imaging control is performed. Under the control of the unit 4, the sixth to eleventh lines are partially read out. At this time, in the present invention, all the pixels 20 in the horizontal direction are read out. Of course, it is also possible to read out only the pixels in the row corresponding to the focus detection areas arranged in the row. Note that, depending on the state of the subject and the like, for example, it is possible to read out signals from only one focus detection area. In the AF readout mode, it is preferable to read out signals from all of the focus detection areas extending in the row direction and the focus detection areas extending in the column direction because the focus adjustment state can be detected with higher accuracy. An example of this will be described later as a third embodiment.

  FIG. 12 shows that when the number of pixels 20 is 4 × 8 as shown in FIG. 2, the first and second lines are skipped and the third line is read and the fourth line is skipped in the AF read mode. It is a timing chart which shows an example. In this example, all pixels in the row direction are read without performing horizontal pixel addition. Further, in this example, for all the pixels 20, an electronic shutter operation is performed in which the exposure time of each pixel has the same length and the same timing. For this reason, as compared with the case of the rolling shutter operation, there is no time difference between the AF signals read out in the same frame, so that the focus detection accuracy can be greatly improved. It should be noted that the exposure times of only the pixels 20 to be read out effectively for the desired focus detection may be the same length and the same timing.

  In the example shown in FIG. 12, in the AF readout mode, all pixels in the row direction are read out for the readout row as described above. However, in the AF read mode, only a part of pixels in a certain column may be read regarding the read row. For example, only the column corresponding to the focus detection area may be read for the pixels in the row direction. In this case, the signal can be read out at higher speed. Such readout of pixels in some columns can be realized, for example, by configuring the horizontal scanning circuit 22 using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208685. . Note that the vertical scanning circuit 21 may be configured by using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208685 in order to partially read out pixels in some rows in the AF read mode. .

  In FIG. 12, with respect to all the pixels 20, the exposure time is from the end point of the period T11 to the start point of the period T12. The period T13 is a selection period for the third row. CDS processing for taking the difference between the signals read in the periods T14 and T15 and the signals read in the periods T16 and T17 is performed by the signal processing unit 5 outside the solid-state imaging device 3. At this time, since the reset period T18 exists between the periods T14 and T15 in which the signal components are acquired and the periods T16 and T17 in which the noise components are acquired, the noise generated in the reset period T18 remains. However, even if such noise remains, the focus detection accuracy is hardly affected.

  In the AE readout mode, assuming that the pixels 20 are arranged as shown in FIG. 4, for example, the first and second rows, which are two consecutive rows as indicated by a circle on the right side in FIG. Are read out, the sixth and tenth lines are skipped and the ninth and tenth lines are read out. As described above, when the reading of even rows is repeated after reading two consecutive rows, since the color filters 50 are arranged according to the Bayer array, pixels of different colors adjacent in the column direction are read out. Thus, the pseudo color can be reduced as compared with the case where there is no row to be read. Therefore, automatic exposure control can be performed with higher accuracy, which is preferable.

  Further, in the signal (AE signal) used for the photometric information for automatic exposure, it is sufficient that there is local averaged information for the resolution, and it may be preferable that the sensitivity is higher than the resolution is increased. Therefore, in the present embodiment, in the AE readout mode, horizontal pixel addition is performed by adding and reading the signals of the four pixels 20 in the row direction. As described above, in the present embodiment, colors are mixed and added, but a pixel in the horizontal direction may be added for each color. In this case, when the unit of the Bayer array is expressed as R, G1, G2, B, for example, two horizontal signal lines 33 are provided for each color (one for G1 and G2 and one for R and B). Alternatively, four (one each of R, G1, G2, and B) may be provided for each color. In the present invention, in the AE readout mode, the signals of all the pixels 20 in the row direction may be read out without performing horizontal pixel addition.

  In the example shown in FIG. 12, in the AE readout mode, as described above, the signals of the pixels 20 in the row direction are read by adding the horizontal pixels. However, in the AE readout mode, only pixels in an arbitrary partial column may be read out without performing horizontal pixel addition with respect to the readout row. Also in this case, the signal can be read out at high speed. Such readout of pixels in some columns can be realized, for example, by configuring the horizontal scanning circuit 22 using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208685. . Note that the vertical scanning circuit 21 may be configured using a shift register circuit as disclosed in Japanese Patent Application Laid-Open No. 2007-208685 in order to partially read out pixels in a part of rows in the AE readout mode. .

  FIG. 13 shows an example in which the first and second rows are read and the third and fourth rows are skipped in the AE read mode when the number of pixels 20 is 4 × 8 as shown in FIG. It is a chart. In this example, four horizontal pixels 20 are added and read out. Further, in this example, for all the pixels 20, an electronic shutter operation is performed in which the exposure time of each pixel has the same length and the same timing. For this reason, compared to the case of the rolling shutter operation, there is no time difference between the imaging signals used for each automatic exposure metering information read out in the same frame, so that the accuracy of the automatic exposure control can be greatly increased. It should be noted that the exposure times of only the pixels 20 to be read out effectively for detecting the desired exposure amount may be the same length and the same timing.

  In FIG. 13, for all the pixels 20, the exposure time is from the end point of the period T21 to the start point of the period T22. The period T23 is a selection period for the first row. CDS processing that takes a difference between a signal read by adding four horizontal pixels in the periods T24 and T25 and a signal read by adding four horizontal pixels in the periods T26 and T27, respectively. This is performed by the signal processing unit 5 outside the solid-state imaging device 3. At this time, since the reset period T28 exists between the periods T24 and T25 in which the signal components are acquired and the periods T26 and T27 in which the noise components are acquired, the noise generated in the reset period T28 remains. However, even if such noise remains, the exposure amount detection accuracy is hardly affected.

  In the electronic camera 1 according to the present embodiment, in the operation mode in which each readout mode is repeated for each frame as shown in FIG. 10 described above, an imaging signal read out in each live view readout mode frame is a signal. A live view display based on the imaging signal is displayed on the liquid crystal display unit 16 by being used by the display control unit 15 via the processing unit 5, the A / D conversion unit 6, and the memory 7. Further, in the operation mode shown in FIG. 10, the AF signal read in each AF read mode frame is used by the focus calculation unit 10 via the signal processing unit 5, the A / D conversion unit 6, and the memory 7, A defocus amount is calculated according to the pupil division phase difference method based on the AF signal, and the lens control unit 2a operates the photographing lens 2 so as to be in a focused state according to the defocus amount, thereby performing automatic focus adjustment. Do. Further, in the operation mode shown in FIG. 10, the AE signal read in each AE read mode frame is used by the exposure calculation unit 14 via the signal processing unit 5, the A / D conversion unit 6 and the memory 7, Based on the AE signal, an optimal exposure amount is calculated, and the lens control unit 2a adjusts the aperture of the photographing lens 2 so as to obtain an exposure amount corresponding to the exposure amount obtained by the exposure calculation unit 14, and also performs imaging. The control unit 4 sets a shutter time corresponding to the exposure amount.

  Thus, the electronic camera 1 according to the present embodiment displays the live view display on the liquid crystal display unit 16 based on the signal read in the live view read mode in the operation mode shown in FIG. Based on the signal read in the AF readout mode, automatic focus adjustment of the taking lens 2 is performed according to the pupil division phase difference method, and automatic exposure control is performed based on the signal read in the AE readout mode. Therefore, the user can see the live view display in the focused state and in the appropriate exposure state. According to the present embodiment, since the AF control based on the pupil division phase difference method is performed as the AF control performed while displaying the live view display, a subject moving at a relatively high speed in a relatively short distance is tracked. Since the live view can be displayed in a focused state, its convenience is immeasurable for the user.

  The operation mode shown in FIG. 10 is started, for example, when the user sets the shooting mode and performs a half-press operation on the release button of the operation unit 9a. For example, when the release button is fully pressed, actual shooting is performed. At this time, since the in-focus state and the appropriate exposure state are obtained before the full-press operation, the shutter can be immediately released and the shutter timing is not missed. At the time of actual photographing, for example, all rows are read without performing thinning in the above-described live view read mode. The imaging control unit 4 accumulates the imaging signal in the memory 7. Thereafter, the microprocessor 9 performs a desired process in the image processing unit 13 or the image compression unit 12 as necessary based on a command from the operation unit 9a, and outputs a processed signal to the recording unit to the recording medium 11a. Record. Note that the operation mode shown in FIG. 10 as described above may be started only by setting the shooting mode, for example, without performing a half-press operation of the release button.

  At the time of actual photographing, in this example, only the electronic shutter is illustrated, but it is obvious that it may be combined with a mechanical shutter.

  In the present embodiment, the live view image signal does not include the output signal of the focus detection pixel, so that a live view image with the same quality as before can be obtained. Also, since the AE row does not match the AF pixel row, highly sensitive and highly accurate AE information can be obtained particularly with respect to the averaging information.

  [Second Embodiment]

  FIG. 14 is a circuit diagram showing a solid-state image sensor 63 used in an electronic camera according to the second embodiment of the present invention, and corresponds to FIG. FIG. 14 also shows 4 × 8 pixels 20 (2 × 8 pixel blocks 70) as in FIG. FIG. 15 is a circuit diagram showing the pixel block 70 of the solid-state imaging device 63 shown in FIG. 14 and 15, elements that are the same as or correspond to those in FIGS. 2 and 3 are given the same reference numerals, and redundant descriptions thereof are omitted.

  This embodiment is different from the first embodiment only in the points described below. In the present embodiment, in the solid-state imaging device 63, for every two pixels 20 adjacent in the column direction, the two pixels 20 share a set of floating diffusion FD, amplification transistor AMP, reset transistor RES, and selection transistor SEL. doing. In FIG. 14 and FIG. 15, two pixels 20 sharing one set of floating diffusion FD, amplification transistor AMP, reset transistor RES, and selection transistor SEL are shown as a pixel block 70. In FIG. 15, the photodiode PD and the transfer transistor TX of the upper pixel 20 in the pixel block 70 are denoted by reference numerals PD1 and TX1, respectively, and the photodiode PD and the transfer transistor TX of the lower pixel 20 in the pixel block 70 are shown. Are indicated by the symbols PD2 and TX2, respectively. Further, the control signal supplied to the gate electrode of the transfer transistor TX1 is φTX1, and the control signal supplied to the gate electrode of the transfer transistor TX2 is φTX2. 2 and 3, n indicates a pixel row, but in FIGS. 14 and 15, n indicates a row of the pixel block 70. For example, the pixel 20 in the first row is constituted by the pixels 20 in the first row and the pixels 20 in the second row, and the pixel block 70 in the second row is constituted by the pixels 20 in the third row and the pixels 20 in the fourth row. Is configured.

  The schematic plan view schematically showing the effective pixel area of the solid-state imaging device 63 in the present embodiment is also basically shown in FIG. 4. For example, a pixel row marked with “○” is read at each reading. However, here, at the time of AE readout, the second and third pixel rows are read out. Also in the present embodiment, as in the first embodiment, in the predetermined operation mode, each readout mode is repeated for each frame as shown in FIG.

  As in the case of FIG. 11, FIG. 16 shows the live view readout mode when the number of pixels 20 is 4 × 8 (the number of pixel blocks 70 is 2 × 8) as shown in FIG. The first pixel row (the upper pixel row of the first pixel block 70) is read, and the second and third pixel rows (the lower pixel row and the second pixel of the first pixel block 70) 12 is a timing chart showing an example of reading out the fourth pixel row (the lower pixel row of the second pixel block 70) by skipping the upper pixel row of the block 70). Also in this example, all pixels in the row direction are read without performing horizontal pixel addition, and an electronic shutter operation using a rolling shutter is performed.

  As in the case of FIG. 12, FIG. 17 shows that when the number of pixels 20 is 4 × 8 (the number of pixel blocks 70 is 2 × 8) as shown in FIG. , The second pixel row (upper pixel row and lower pixel row of the first pixel block 70) is skipped, and the third pixel row (upper pixel row of the second pixel block 70) is read out. 12 is a timing chart showing an example of skipping a fourth pixel row (a lower pixel row of a second pixel block 70). Also in this example, all the pixels in the row direction are read without performing horizontal pixel addition, and the electronic shutter operation is performed for all the pixels 20 so that the exposure times of the respective pixels have the same length and the same timing. ing.

  FIG. 18 differs from FIG. 13 in the case where the number of pixels 20 is 4 × 8 (the number of pixel blocks 70 is 2 × 8) as shown in FIG. The first pixel row (the upper pixel row of the first pixel block 70) is skipped, and the second and third pixel rows (the lower pixel row and the second pixel block of the first pixel block 70) are skipped. 70 is a timing chart showing an example in which the upper pixel row (70) is read and the fourth pixel row (lower pixel row of the second pixel block 70) is skipped. In this example as well, four horizontal pixels 20 are added and read out, and for each pixel 20 to be read out, an electronic shutter operation is performed in which the exposure time of each pixel is the same length and the same timing. ing.

  Also in this embodiment, the same advantages as those in the first embodiment can be obtained. Further, according to the present embodiment, since the two pixels 20 share one set of the floating diffusion FD, the amplification transistor AMP, the reset transistor RES, and the selection transistor SEL, the number of transistors per pixel can be reduced. And the aperture ratio can be increased.

  By the way, as in this embodiment, photoelectric conversion units (photodiodes) are sequentially arranged in the column direction for each of L pixels 20 (L is an integer of 2 or more. In this embodiment, L = 2). When the pixel block 70 is formed and the L pixels 20 belonging to the pixel block 70 share one set of the floating diffusion FD, the amplification transistor AMP, the reset transistor RES, and the selection transistor SEL for each pixel block 70, (i ) In the AE readout mode, the condition that the signals of the pixels in the M rows (M is an even number) are repeatedly skipped after the signals of the pixels 20 in the two consecutive rows are read out with respect to the signal readout in the column direction, and (ii) It is preferable that the condition that M is {L × (2 + N) −2} (N is an integer of 0 or more) is satisfied. By satisfying the condition (i) above, pixels of different colors adjacent to each other in the column direction are read out, so that pseudo colors can be reduced compared to the case where there are no rows to be read out continuously, and thus automatic exposure. Control can be performed with higher accuracy. By satisfying the above condition (ii), the pixel block 70 shares one set of floating diffusion FD, amplification transistor AMP, and the like, but has the same exposure time for the pixel row to be read and Electronic shutter operation at the same timing is possible, and as a result, there is no time difference between imaging signals used for each automatic exposure metering information read out in the same frame, so that the accuracy of automatic exposure control can be greatly increased. .

  In order to facilitate the understanding, an example of L = 2, N = 0, M = 2 is shown in FIG. 19, an example of L = 2, N = 2, M = 6 is shown in FIG. 20, and L = 2, An example of N = 4 and M = 10 is shown in FIG. In FIG. 19 to FIG. 21, the colors of the pixels in each row are represented by alternating colors of G and R on the assumption of the Bayer arrangement. For example, L = 2, N = 12, and M = 26 may be set. Further, when L = 4, M may be any one of 6, 10, 14, and 18, and when L = 6, M may be any one of 10, 16, 22, and 28, for example. .

  [Third Embodiment]

  FIG. 22 is a schematic plan view schematically showing an effective pixel region of a solid-state imaging device used in an electronic camera according to the third embodiment of the present invention, and corresponds to FIG. 22, elements that are the same as or correspond to those in FIG. 4 are given the same reference numerals, and redundant descriptions thereof are omitted.

  This embodiment differs from the first embodiment only in the rows that are read in the AF read mode. In the first embodiment, in the AF readout mode, the third, eighth, and fourteenth rows corresponding to the three focus detection areas extending in the row direction are read out as indicated by a circle on the right side in FIG. ing. In contrast, in the present embodiment, in the AF readout mode, as indicated by a circle on the right side in FIG. 22, three focus detection areas extending in the row direction and three focus detection areas extending in the column direction The third, sixth to eleventh and fourteenth rows corresponding to all of the above are read out. The timing chart in this case is obtained by modifying the timing chart in the AF readout mode in the case of the first embodiment in accordance with the readout row. However, in the range up to the fourth line, the skip-read line and the read line are the same as in the first embodiment in this embodiment. Therefore, the timing chart up to the fourth line in the AF read mode according to the present embodiment is the same as FIG.

  According to the present embodiment, in the AF read mode, signals are read from all of the focus detection areas extending in the row direction and the focus detection areas extending in the column direction. Therefore, according to the present embodiment, the focus adjustment state can be detected with higher accuracy.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

  For example, in each of the above-described embodiments, an example in which the three readout modes of the live view readout mode, the AF readout mode, and the AE readout mode are sequentially and repeatedly performed has been described. Alternatively, only the two readout modes of the AF readout mode may be sequentially repeated cyclically. In this case, for example, a detector for obtaining photometric information for automatic exposure may be provided separately from the solid-state imaging device, and automatic exposure control may be performed by a signal from the detector.

1 is a schematic block diagram showing an electronic camera according to a first embodiment of the present invention. It is a circuit diagram which shows schematic structure of the solid-state image sensor in FIG. It is a circuit diagram which shows the pixel of the solid-state image sensor in FIG. It is a schematic plan view which shows typically the effective pixel area | region of the solid-state image sensor in FIG. It is a figure which shows typically the principal part of the pixel for imaging in FIG. It is a figure which shows typically the principal part of the predetermined AF pixel in FIG. It is a figure which shows typically the principal part of the other predetermined AF pixel in FIG. It is a figure which shows typically the principal part of the other predetermined AF pixel in FIG. It is a figure which shows typically the principal part of the other predetermined AF pixel in FIG. 2 is a timing chart schematically showing a signal reading state from a solid-state image sensor when the electronic camera shown in FIG. 1 is in a predetermined operation mode. 3 is a timing chart showing an operation example of a live view readout mode of the electronic camera shown in FIG. 1. 3 is a timing chart illustrating an operation example of an AF readout mode of the electronic camera illustrated in FIG. 1. 3 is a timing chart illustrating an operation example of an AE readout mode of the electronic camera illustrated in FIG. 1. It is a circuit diagram which shows the solid-state image sensor used with the electronic camera by the 2nd Embodiment of this invention. It is a circuit diagram which shows the pixel block of the solid-state image sensor shown in FIG. It is a timing chart which shows the operation example of the read-out mode for live views of the electronic camera by the 2nd Embodiment of this invention. It is a timing chart which shows the operation example of AF read mode of the electronic camera by the 2nd Embodiment of this invention. It is a timing chart which shows the operation example of AE read-out mode of the electronic camera by the 2nd Embodiment of this invention. It is a figure which shows the example of the reading line of AE reading mode. It is a figure which shows the other example of the read-out line of AE read-out mode. It is a figure which shows the further another example of the read-out line of AE read-out mode. It is a schematic plan view which shows typically the effective pixel area | region of the solid-state image sensor used with the electronic camera by the 3rd Embodiment of this invention.

Explanation of symbols

3 Solid-state imaging device 20a, 20b, 20c, 20d AF pixel 20e Imaging pixel

Claims (9)

A plurality of pixels arranged two-dimensionally, each having a photoelectric conversion unit that generates and accumulates signal charges corresponding to incident light from a subject image formed by an optical system;
Read control means for performing control to read signals from the plurality of pixels,
With
The plurality of pixels include a plurality of imaging pixels that output imaging signals for forming an image signal indicating the subject image, and a focus for detecting a focus adjustment state of the optical system according to a pupil division phase difference method. A plurality of focus detection pixels that output detection signals;
The read control means sequentially and repeatedly performs two or more read modes for each frame during a predetermined operation mode,
The two or more read mode, the live view readout mode for reading an image signal for a live view display, and a read mode for focus detection to read out the focus detection signal, seen including,
The two or more readout modes include an automatic exposure readout mode for reading out an imaging signal for use in automatic exposure metering information,
A vertical signal line provided corresponding to each column of the plurality of pixels to which an output signal of the pixel in the corresponding column is supplied;
In the automatic exposure readout mode, horizontal pixel addition is performed by adding and reading signals of two or more pixels in the row direction,
In the readout mode for automatic exposure, with respect to signal readout in the column direction, reading out signals of pixels in M rows (M is an even number) after reading out signals of pixels in two consecutive rows is repeated,
Each of the plurality of pixels receives the signal charge from the photoelectric conversion unit of the pixel and converts the signal charge into a voltage, and outputs a signal corresponding to the potential of the charge voltage conversion unit. An amplification unit, a charge transfer unit that transfers charges from the photoelectric conversion unit to the charge voltage conversion unit, a reset unit that resets the potential of the charge voltage conversion unit, and a selection unit that selects the pixel,
The plurality of pixels form a pixel block for each of L pixels (L is an even number of 2 or more) in which the photoelectric conversion units are sequentially arranged in a column direction,
For each pixel block, the L pixels belonging to the pixel block share a set of the charge-voltage conversion unit, the amplification unit, the reset unit, and the selection unit,
The M is {L × (2 + N) −2} (N is an integer of 0 or more).
A solid-state imaging device. Prior Symbol for live view read mode, the solid-state imaging device according to claim 1, wherein the signal reading pixels thinned out in the column direction is performed.   The electronic shutter operation in which the exposure time of each pixel has the same length and the same timing is performed on the pixel from which a signal is to be read out effectively in the focus detection readout mode. 2. The solid-state imaging device according to 2.   4. The solid-state imaging device according to claim 1, wherein in the focus detection readout mode, partial readout for reading out signals of pixels in a partial area is performed. 5. In the automatic exposure reading mode, with respect to the pixel to be read out signal effectively, 1 to claim, characterized in that the electronic shutter operation exposure time of each pixel is the same in the same timing and the length is carried out 5. The solid-state imaging device according to any one of 4 above. Each of the plurality of pixels receives the signal charge from the photoelectric conversion unit of the pixel and converts the signal charge into a voltage, and outputs a signal corresponding to the potential of the charge voltage conversion unit. An amplification unit, a charge transfer unit that transfers charges from the photoelectric conversion unit to the charge-voltage conversion unit, a reset unit that resets the potential of the charge-voltage conversion unit, and a selection unit that selects the pixel, the solid-state imaging device according to any one of claims 1 to 5. The plurality of imaging pixels, the solid-state imaging device according to any one of claims 1 to 6, characterized in that color filters arranged according Bayer array is provided. A solid-state imaging device according to any one of claims 1 to 7 and a display unit capable of performing live view display,
In the predetermined operation mode, while the live view display is displayed on the display unit based on the signal read in the live view read mode, the optical signal is read based on the signal read in the focus detection read mode. An electronic camera characterized by automatic focusing of the system. A solid-state imaging device according to any one of claims 1 to 7 and a display unit capable of performing live view display,
In the predetermined operation mode, while displaying a live view display on the display unit based on the signal read in the live view readout mode, pupil division based on the signal read in the focus detection readout mode An electronic camera that performs automatic focus adjustment of the optical system according to a phase difference method, and performs automatic exposure control based on a signal read in the read mode for automatic exposure.

Images