JP2000292685A - Image pick-up element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pick-up element capable of contributing to cost reduction and space-saving and capable of realizing a highly precise focus adjustment function. SOLUTION: This element is an image pick-up element for transferring photoelectrically an optical image imaged on a photoreceiving face after transmitted through a photographing optical system. The image pick-up element is provided with a first micro-lens array 106 and a second micro-lens array 206 respectively arrayed two-dimensionally with the receiving face as a focal position, a first photo-receiving element group 101 arranged in a focal position of the first micro-lens array 106, and having a single photo-receiving element as a constitutional unit for outputting the first image signals respectively, and a second photo-receiving element groups 201a, 201b arranged in a focal position of the second micro-lens array 206, and having a pair of photo-receiving elements as a constitutional unit for outputting the second image signals respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image pickup device, and more particularly to an image pickup device used in an electronic image pickup device having an automatic focusing device and capable of acquiring an electronic image.

[0002]

2. Description of the Related Art In recent years, an optical image of a subject formed by a photographing optical system such as a photographing lens or the like has been changed to a CCD (Charge Couple).
The photoelectric conversion into an electric signal is performed by using an imaging device including a pled device (charge coupled device), and the obtained electric image signal (also referred to as a video signal) is converted into image data (video data) such as digital data. Digital still camera, digital video camera, or the like (hereinafter, referred to as an electronic imaging device) configured to be able to record on a predetermined recording medium or the like
Are widely spread.

In such a conventional electronic image pickup apparatus, a focus position with respect to a desired subject image is detected using an image pickup device, and a predetermined drive mechanism or the like is provided so as to obtain the detected focus position. A camera having an automatic focusing device (AF means) that automatically performs a focusing operation by moving a predetermined photographing lens or the like using the camera is generally put into practical use. In this case, various types of AF means have been proposed and put to practical use. For example, a so-called hill-climbing AF unit is applied as an AF unit in an electronic imaging apparatus disclosed in Japanese Patent Application Laid-Open No. 10-21737.
The hill-climbing AF means detects the maximum value of the contrast of an optical image (subject image) transmitted through a photographic optical system such as a photographic lens and formed on a light receiving surface of an image sensor. Is determined.

On the other hand, AF in a conventional electronic image pickup apparatus
As the means, there is an AF means of a TTL phase difference detection method. As this method, for example, Japanese Patent Application Laid-Open No. 10-19778
No. 3 and Japanese Patent Publication No. 57-49841,
Various proposals have been made in, for example, JP-A-274562.

The AF means in the electronic imaging apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 10-197783 drives a diaphragm member to perform pupil division processing in a time-division manner.
At this time, the luminous flux passing through each aperture (pupil) of the aperture member is
The phase difference is detected by receiving light with a single image sensor.

The AF means such as an electronic image pickup apparatus disclosed in the above-mentioned Japanese Patent Publication No. 57-49841 is a so-called fly-lens method, which comprises a line sensor for transmitting a light beam transmitted through a lens array. A focusing lens that receives light by a pair of light receiving elements and processes a signal output from the line sensor to calculate an image shift amount, that is, a phase difference amount, and constitutes a part of a photographing lens and controls focus. The automatic focus adjustment operation is realized by calculating the amount of feeding.

The AF means in the electronic imaging apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 10-274562 is an AF means of a TTL phase difference detection method called a so-called re-imaging method, and transmits through a photographing lens. The light flux from the subject is condensed by a condenser lens, further divided into two by a separator lens, and two subject images are re-imaged on the light receiving surface of a light receiving element (photoelectric conversion element). The focus position is detected by the detection.

[0008]

However, the hill-climbing AF means disclosed in Japanese Patent Laid-Open No. Hei 10-21737 mentioned above forms an image on the light receiving surface of the image sensor while moving the photographing lens. After detecting the position at which the subject image has the maximum contrast, the photographing lens is moved to a predetermined position, which generally requires a long focus detection time, and the operation when executing the automatic focus adjustment operation There is a problem that the speed is reduced.

Further, according to the means disclosed in Japanese Patent Application Laid-Open No. H10-197783, a pupil division process is performed by driving a mechanical diaphragm member.
A separate drive mechanism for the aperture member is required, and a space for installing components and the like is also required. Therefore, in order to reduce the size of a device that has been particularly demanded recently,
This is a disadvantage.

Further, in the means disclosed in the publication, the pupil division processing is performed by time division, so that a time difference occurs between the acquired images. Therefore, there is a problem that the detection accuracy of a subject moving at high speed may be significantly deteriorated. In addition, the means disclosed in the publication requires a predetermined time for driving a mechanical diaphragm member, and thus has a problem that the focus detection speed is reduced. It is also a difficult problem to maintain mechanical precision precisely.

On the other hand, according to the means disclosed in JP-B-57-49841 or JP-A-10-274562, a part of a light beam from an object transmitted through a photographing lens is divided into predetermined light beams. It is necessary to guide the lens array, condenser lens, and the like arranged at the position (1), and there is a problem that optical and spatial restrictions are imposed.

In the means disclosed in Japanese Patent Application Laid-Open No. Hei 10-274562, it is necessary to newly provide a re-imaging optical system, so that spatial restrictions inside the electronic image pickup apparatus become large. In addition, there is a problem that the miniaturization of the electronic imaging device is hindered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a purpose thereof is to newly add constituent members such as a mechanism member for focus detection and an optical member constituting an optical system. And the focus detection speed can be improved without increasing the size of the applied electronic imaging device, thereby contributing to cost reduction and space saving and realizing a highly accurate focus adjustment function. It is an object of the present invention to provide an imaging device which can obtain the same.

[0014]

In order to achieve the above object, a camera according to a first aspect of the present invention is an imaging device for photoelectrically converting an optical image transmitted through a photographing optical system and formed on a light receiving surface. A first micro-lens array and a second micro-lens array arranged two-dimensionally, and a first video signal is output near the focal position of the first micro-lens array. A first light receiving element group having a single light receiving element as a constituent unit, and a second light receiving element arranged near a focal position of the second microlens array and having a pair of light receiving elements each outputting a second video signal. A light receiving element group.

According to a second aspect of the present invention, in the camera according to the first aspect, a Bayer-arranged color filter is interposed at least in an optical path of the first microlens array. .

According to a third aspect of the present invention, in the camera according to the first aspect, the first micro lens array and the second micro lens array are different from each other in focal length and / or curvature.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram showing components constituting a main optical system in an electronic image pickup apparatus having an image pickup device according to a first embodiment of the present invention. FIG. 3 shows an optical path of a light beam (referred to as a light beam) in the electronic imaging apparatus.

As shown in FIG. 1, the optical system in the electronic image pickup apparatus includes a photographing optical system 11 for condensing a subject light beam,
An imaging system that performs imaging by photoelectrically converting the subject image based on the subject light beam, a finder optical system 20 that visually observes the subject image, and an imaging system that divides the subject light beam condensed by the photographing optical system 11 into two parts. Viewfinder optical system 20
And a divided optical system leading to the above.

The photographing optical system 11 can hold a predetermined aperture, a plurality of lenses including a focusing lens 11a for adjusting the focus by moving in the optical axis direction, and has a shutter function. The aperture unit 12 and the like also have a function of completely blocking light beams.

The splitting optical system is constituted by a beam splitter 13 and the like which are arranged at a predetermined position on the optical axis behind the photographing optical system 11 and comprise a plurality of prisms and the like so as to split the light beam of the subject. I have.

In the vicinity of the beam splitter 13, various members constituting an imaging system for converting a subject image formed by subject light transmitted through the photographing optical system 11 into an electric signal and generating an image signal are arranged. I have. The imaging system includes an infrared light cut filter 14 for transmitting a part of a subject light beam split by a beam splitter 13 to remove an infrared light component, and an optical low-pass filter for reducing noise components such as moiré. (Hereinafter simply referred to as LPF) 15
And an imaging element (hereinafter, simply referred to as a CCD) 16 such as a CCD for photoelectrically converting an optical subject image.

The finder optical system 20 is provided at a predetermined position behind the beam splitter 13 and on the optical axis of the photographing optical system, and is provided at an angle of about 45 degrees with respect to the optical axis. A first mirror 17 composed of a reflection mirror,
A second mirror 18 disposed on the optical axis of the subject light beam reflected by the first mirror 17 and arranged at an angle of approximately 45 degrees with respect to the optical axis, and reflected by the second mirror 18 It is composed of a finder eyepiece 19 and the like for transmitting a subject light beam to form a subject image for observation.

In the electronic imaging apparatus thus configured, the subject light beam first enters the photographing optical system 11,
The amount of light is regulated by the aperture unit 12 so as to have a desired light amount. In a predetermined case, for example, during transfer of accumulated charges by the CCD 16, the aperture unit 12 blocks the subject light beam as necessary.

The luminous flux transmitted through the photographing optical system 11 is split into two by the beam splitter 13, and a part of the luminous flux is guided to the imaging system side, and the infrared light cut filter 1
4. It is led to the CCD 16 via the LPF 15. Then, a subject image is formed on the light receiving surface of the CCD 16.

On the other hand, another part of the subject light beam split into two by the beam splitter 13 passes through the beam splitter 13, goes straight, and is guided to the finder optical system 20.

A part of the subject light beam guided to the finder optical system 20 is firstly transmitted by the first mirror 17.
The electronic mirror is bent at an angle of about 90 degrees and heads upward from the electronic imaging apparatus.
It is bent by 0 degrees and heads toward the eyepiece 19 arranged behind. Then, by passing through the eyepiece 19, a subject image for observation is formed. As a result, the user of the electronic imaging apparatus is ready to observe the subject image with his own eyes. The subject image formed by the finder optical system 20 is C
This is substantially equivalent to a subject image formed on the light receiving surface of the CD 16.

Next, the configuration of the electric system of the electronic imaging apparatus will be described below. FIG. 2 is a main block configuration diagram showing electrical components of the electronic imaging apparatus.

The entire electronic imaging apparatus is controlled by a microcomputer 31 which is a control means including a central processing unit (hereinafter, referred to as a CPU) 31a. That is, the microcomputer 31 is a control device of the present electronic imaging device system, and has a CPU 31a therein.
, A ROM 31b, a RAM 31c, an A / D converter (ADC) 31d, an EEPROM 31e, and the like. And the microcomputer 31
A series of operations in the electronic imaging apparatus is controlled according to a sequence program stored in the ROM 31b inside the electronic imaging device in advance. Also, EEPRO
M31e includes focus adjustment calculation, photometry and exposure calculation, AW
Correction data specific to B (auto white balance) calculation and the like is stored in advance.

The microcomputer 31 includes an aperture driving section 33 for driving and controlling the aperture section 12 (see FIG. 1), and a focusing lens 11.
a (see FIG. 1), etc.
A switch group that generates various command signals in conjunction with various operation members (not shown), for example, a command group that generates a command signal for executing a preliminary operation such as photometry and AF operation when starting a shooting operation. A release switch (1RSW) 47, a second release switch (2RSW) 48 for driving the aperture unit 12 and the like to generate a command signal for executing an exposure operation, a plurality of types of AF areas ( An area selection switch 49 or the like for generating a command signal for selecting and specifying a predetermined area for performing focus detection) is electrically connected. The 1RSW 47 and the 2RSW 48 are configured to be operated by a single operation member, and are in the form of a so-called two-stage switch.

The microcomputer 31 includes a timing generator (hereinafter, referred to as TG) 82 and a signal generator (hereinafter, referred to as SG) 83 and the like (see FIG. 3).
3 are electrically connected. The CCD 16 is electrically connected to the CCD control section 43 to control the driving of the CCD 16.

The CCD 16 converts an optical subject image formed by a subject light beam transmitted through the photographing optical system 11 into an electric signal. C in the electronic imaging device
As CD16, vertical overflow drain type CC
D is applied, and its detailed configuration will be described later (see FIGS. 4 to 12).

A video signal processor 42 is electrically connected to the CCD 16. The video signal processing unit 42
The output signal from the CD 16 is subjected to predetermined processing to generate an image signal in a predetermined form. The video signal processing unit 42 is electrically connected to a focus detection calculation unit 50, a photometry / exposure calculation unit 45, an AWB unit 51, a display unit 46, a recording unit 44, and the like. For each of them, an image signal in an optimal form and information accompanying the image signal are generated and output.

The focus detection calculation section 50 is provided with a video signal processing section 4
2 is a circuit for detecting and calculating the focal position in response to the output signal from the microcomputer 2, the calculation result, the data for determining the in-focus state, and the predetermined driving amount data for the focusing lens 11a are stored in the microcomputer 3
1 is output.

The photometry / exposure calculation unit 45 receives the output signal from the video signal processing unit 42, detects the brightness of the subject, and optimizes the exposure data, that is, the aperture value of the aperture unit 12 and the CC.
D16 is a circuit for calculating the electronic shutter speed value and the like, and the calculation result is output to the microcomputer 31. Then, in response to this, the microcomputer 31
Drives the aperture unit 12 to have a predetermined aperture value via the aperture driving unit 33 and drives and controls the CCD 16 at a predetermined electronic shutter speed value via the CCD control unit 43.

The AWB unit 51 is a circuit for receiving the output signal from the video signal processing unit 42 and automatically adjusting the white balance of the subject to be optimal. The image signal thus output is output to the display unit 46.

The display section 46 is formed by an image display device such as a liquid crystal display (LCD), and can display an image signal input through the video signal processing section 42 and the AWB section 51 as an image. This is for visually displaying, in the form of characters, symbols, and the like, photographing information and the like accompanying the signal, internal information of the electronic image pickup apparatus itself such as a photographing mode, and the like.

The recording section 44 receives an output signal from the video signal processing section 42 and records an image signal and accompanying photographing information and the like (hereinafter referred to as an image signal) in a predetermined form.

Here, the video signal processing section 42 and the recording section 4
4. Details of the CCD controller 43 will be described below. FIG. 3 is a main block diagram showing a video signal processing unit 42 and a recording unit 44 of the present electronic imaging apparatus and a part of a main electric circuit electrically connected thereto.

The video signal processing section 42 is a correlated double sampling circuit (hereinafter referred to as CDS) 78 for removing reset noise and the like from the image signal obtained by the CCD 16.
And a gain control amplifier (hereinafter referred to as AMP) for amplifying the output of the correlated double sampling circuit 78.
And an AD converter (hereinafter referred to as A) that receives the output (analog signal) of AMP 79 and converts it into a digital signal.
/ D) 80, and a process processing circuit 81 for performing predetermined processing on the image signal converted into a digital signal by the A / D 80.

As described above, the CCD control unit 43
A predetermined operation is controlled by outputting a drive signal to D16, and has the following configuration. That is, the TG 82 constituting the CCD control unit 43 is the CCD 1
And a drive signal such as a transfer pulse for driving the A / D converter 6, a sample hold pulse of the correlated double sampling circuit 78 of the video signal processing unit 42, and an AD conversion timing pulse of the A / D converter 80. is there.

SG8 constituting the CCD controller 43
Reference numeral 3 denotes a signal for synchronizing the TG 82 and the microcomputer 31. Then, the CCD controller 4
3 is a photometry / exposure calculation unit 45 according to a command from the microcomputer 31.
The electronic shutter of the CCD 16 at the time of exposure, that is, the function of controlling the exposure time, is performed based on the calculation result.

The recording unit 44 receives the output signal from the video signal processing unit 42 as described above, and converts the image signal and its associated shooting information and the like (hereinafter referred to as an image signal) into an image data file of a predetermined form. , Can be stored in the recording medium 86.

That is, the recording unit 44 includes the video signal processing unit 42
DR which receives and temporarily stores an image signal output from the process processing circuit 81 and shooting information associated therewith.
An AM 84, a recording medium 86 for storing and storing the image signals and the like in a predetermined area as an image data file, and a DRAM.
In addition to performing compression processing and the like for processing an image signal or the like input via the recording signal 86 into an optimal signal for recording the image signal or the like on the recording medium 86 as an image data file, the recording medium 86
And a compression / decompression circuit 85 comprising a decompression circuit for processing the image data file recorded in the.

Next, the image pickup device of this embodiment, that is, the CCD
The detailed configuration of 16 will be described below. FIG. 4 and FIG. 5 are enlarged views showing the main parts of a part of the CCD 16 which is the image sensor of the present embodiment.

The CCD 16 of this embodiment is an interline transfer type CCD. A plurality of light receiving elements are arranged side by side on the light receiving surface, and each light receiving element is configured to form one pixel.

As shown in FIG. 4, the CCD 16 includes an image pickup section 100 that uses individual pixel signals constituting the entire image signal obtained for image pickup, and a focus that uses each pixel signal to perform focus detection. The detection unit 200 is functionally constituted by two parts. And the imaging unit 1
00 and the focus detection unit 200 are alternately arranged for each row.

The imaging section 100 of the CCD 16 includes a photodiode 101 as a first light receiving element group arranged two-dimensionally in the horizontal direction and the vertical direction, and a photodiode 10.
A transfer gate 102 for transferring the electric charge (first video signal) accumulated in 1 to the vertical shift register 103;
A vertical shift register 103 for sequentially transferring the transferred charges in the vertical direction; a horizontal shift register 104 for sequentially transferring the charges transferred in the vertical direction by the vertical shift register 103 in the horizontal direction;
And an output unit 105 that converts the charges transferred in the horizontal direction into voltage signals and outputs the voltage signals.

Also, adjacent to the imaging unit 100, the imaging unit 10
The focus detection units 200 alternately arranged with 0 are two-dimensionally arranged in the horizontal direction and the vertical direction, and are microlenses (illustrated in FIG. 4) which are microlens groups arranged in front of each light receiving element. A pair of photodiodes 201a and 201b, which are a second light receiving element group for receiving the light fluxes divided by the respective light-receiving elements, and charges (second video signals) accumulated in the photodiodes 201a and 201b. A transfer gate 202 for transferring the transferred charges to a vertical shift register 203; a vertical shift register 203 for sequentially transferring the transferred charges in the vertical direction; and a horizontal shift for sequentially transferring the charges transferred in the vertical direction by the vertical shift register 203 in the horizontal direction. The electric charge transferred in the horizontal direction by the register 204 and the horizontal shift register 204 is converted into a voltage signal. It is constituted by the output unit 205 for outputting Te.

Note that the vertical shift registers 103 and 203, the horizontal shift registers 104 and 204, and the output units 105 and 205 of the imaging unit 100 and the focus detection unit 200 are separated from each other. This is for optimally setting the amount and improving the transfer efficiency.

Each light receiving element (photodiode 101.2
The first microlens array 106 and the second microlens array 2 are provided on the front surface of the first microlens array 106a and the second microlens array 2a, respectively, as shown in the enlarged view of the main part of FIG.
06 is arranged. Among them, the first microlens array 106 is arranged corresponding to each light receiving element in order to improve the light sensitivity of the imaging element (CCD 16).

By providing the microlens array (106) on the front surface of each light receiving element, that is, on the light incident surface side, there is an effect that the incident light can be efficiently collected. Such a configuration is generally used in practice, and is called an on-chip microlens. In the imaging unit 100, the first micro lens array 106
Is set so that the light sensitivity is optimal as described above. Further, the second micro lens array 206 corresponding to the focus detection unit 200 has optical characteristics different from those of the first micro lens array 106 described above, and serves to split incident light into a pair of photodiodes 201a and 201b. (Details will be described later).

FIG. 6 is a diagram showing a detailed configuration of a conventional solid-state image pickup device (CCD) in which an on-chip micro lens is formed. It is sectional drawing of the direction orthogonal to a direction. An outline of the configuration of the conventional solid-state imaging device will be described below with reference to FIG.

The conventional CCD 116 is configured as follows. That is, for example, the semiconductor substrate 1 made of a silicon material or the like
Inside 31, a charge transfer section 132 constituting the vertical shift register 103 and a photodiode 101 constituting a light receiving section are formed by a diffusion layer or the like.

A transparent flattening layer 136 is formed on the upper surface side of the charge transfer portion 132 and the photodiode 101. Inside the transparent flattening layer 136, an insulating film (above the charge transfer portion 132) is formed. A vertical transfer electrode 134 is formed via a not shown). Further, a light shielding film 135 is formed so as to cover the vertical transfer electrode 134.

The photodiode 101 is formed so as to correspond to the opening of the light-shielding film 135, and the upper part of the photodiode 101 and the upper part of the light-shielding film 135, that is, the upper surface of the transparent flattening layer 136, have a color. Filter 137
Are formed.

Further, a transparent flattening layer 136 is also provided on the color filter 137, and the microlens 106 (in the present embodiment) is formed integrally with the transparent flattening layer 136 and has a predetermined curvature r and a focal length f1. Form imaging device 1
6 (corresponding to the first micro lens array 106).

The image pickup device CC of the present embodiment
The imaging unit 100 in D16 has substantially the same configuration as the configuration of an imaging device having a conventional general on-chip microlens shown in FIG. That is, as shown in FIG. 4 and the like described above, the CCD 16 of the present embodiment has the focus detection unit 200 and the corresponding second microlens array 206 arranged in a predetermined arrangement in addition to the above-described conventional imaging device. What is different is that.

On the other hand, the second microlens array 206 corresponding to the focus detection unit 200 has different optical characteristics, that is, different curvature and different focal length from the first microlens array 106 in the above-described imaging unit 100. Is formed. Then, on the focal plane of the second micro lens array 206, photodiodes 201a and 201b as a pair of light receiving elements are arranged.

The second micro lens array 206
Is formed so as to receive a light beam transmitted through the imaging optical system 11, pupil-divide the light beam as shown in FIG. 7, and make each light beam enter a pair of photodiodes 201a and 201b. The principle of the focus detection operation performed by the CCD 16 according to the present embodiment configured as described above is the same as that of the phase difference detection method disclosed in Japanese Patent Publication No. 57-49841 described above. Therefore, the operation at the time of the focus detection operation follows general means, and a detailed description thereof will be omitted in this specification.

FIG. 8 shows an optical path diagram of a light beam incident on the focus detection unit 200 of the CCD 16 of the present embodiment, and shows the same case when in a focused state, in a front focus state, and in a rear focus state. This is shown in the drawing.

In FIG. 8, for convenience of explanation, the image pickup device (CCD) is fixed with the photographing optical system fixed.
16) are moved in the direction of the arrow X1 or the arrow X2 to show the respective states.
In an electronic imaging apparatus to which the CD 16) is applied, the imaging device (CCD 16) is actually fixed, and the focus state is adjusted by moving the focusing lens 11a of the imaging optical system 11 in the optical axis direction. (See FIG. 1).

In FIG. 8, the second microlens arrays 206 constituting the CCD 16 are respectively denoted by L1, L2,.
Ln and photodiodes 201a and 2 serving as light receiving elements
01b to A1, A2... An and B1, B2.
It is shown as n.

The focal length of the micro lens Ln is set to f2, and this focal length is set to be substantially equal to the distance between the micro lens Ln and the photodiodes An and Bn.

In the case where such a model of the CCD 16 is assumed, when the camera is in a focused state, the reference numeral B in FIG.
(CCD 16B). That is, light beams R1, R2, R3, R4, which are light beams emitted from the same subject and pass through different exit pupils, enter each microlens Ln, and are adjacent to each other around the optical axis of the microlens Ln. The amounts of light received by the matching photodiodes An and Bn are the same.

For example, the light rays R3 and R4 both enter the microlens L2, are pupil-divided by the microlens L2, and are respectively received by the photodiodes A2 and B2. At this time, the amounts of light received by the photodiodes A2 and B2 match.

On the other hand, when the camera is in the front focus state, it becomes as shown by the symbol A (CCD 16A) in FIG. That is, the amount of light received by the photodiodes An and Bn to which the light flux transmitted through the different microlenses Ln reaches is the same at the photodiodes An and Bn that are not adjacent to each other.

For example, rays R3 and R4 from the same subject
Respectively enter the microlenses L3 and L1, and are received by the photodiodes B3 and A1. Therefore, in this case, the image is shifted by two pitches.

On the other hand, in the case of the back focus state, the state is as shown by the symbol C (CCD 16C) in FIG. That is, the photodiodes An and Bn having the same amount of received light are adjacent to each other, but the light rays incident on the adjacent photodiodes An and Bn are light beams transmitted through different microlenses Ln.

For example, rays R3 and R4 from the same subject
Respectively enter the microlenses L1 and L3 and are received by the photodiodes B1 and A3. Therefore, in the image formation at this time, an image shift of two pitches occurs in the direction opposite to the case of the above-described front focus state.

In practice, a high-precision focus detection accuracy cannot be ensured with an image shift amount (phase difference amount) of one pitch unit. Accordingly, focus detection for one pitch or less is performed by performing processing such as a predetermined interpolation operation. Note that, for the predetermined interpolation calculation and the like, a means that has been generally put to practical use is used, and a detailed description thereof will be omitted. In this way, by detecting the amount of image shift, the in-focus position of the photographing optical system can be obtained.

As described above, the color filter 137 is disposed on the front surface of the photodiode 101 constituting the image pickup unit 100 (see FIG. 6). The arrangement of the color filters 137 is a so-called Bayer arrangement (see FIG. 9).

FIG. 9 is a diagram showing an arrangement of color elements of the color filter 137 in the image pickup device (CCD 16) of the present embodiment. Note that the CCD 16 of the present embodiment is
Is actually configured such that the imaging units 100 and the focus detection units 200 are alternately arranged as described above. However, in FIG. 9, for convenience of explanation, only the imaging unit 100 is two-dimensionally arranged. 3 shows an arrangement of color elements on a light receiving surface of a color filter corresponding to an image sensor arranged in a line, and excludes a portion corresponding to a focus detection unit 200.

In FIG. 9, reference characters R, G, and B denote respective color filter elements capable of selectively transmitting red, green, and blue, respectively. The arrangement is a general Bayer arrangement as shown in FIG. Note that, in the CCD 16 of the present embodiment, no color filter is disposed on the front surfaces of the pair of photodiodes 201a and 201b of the focus detection unit 200.

The CCD 16 of this embodiment is configured as described above. As described above, the CCD of the present embodiment
The 16 light receiving surfaces are configured such that the imaging units 100 and the focus detection units 200 are alternately arranged. Therefore, the focus detection unit 200 is formed on substantially the entire light receiving surface of the CCD 16. From this, the CCD of the present embodiment
In the electronic imaging apparatus to which the image capturing apparatus 16 is applied, substantially the entire photographing screen 300 is formed as shown in FIG.
It is configured to be able to.

Then, the photographer sets the area selection switch 4
9 (see FIG. 2) to select a desired region for which focus adjustment is to be performed, and to arbitrarily perform an automatic focus adjustment operation (hereinafter, referred to as “focus adjustment”)
AF operation). Since the means for selecting the focus adjustment area by the area selection switch 49 is not directly related to the present invention, a detailed description thereof will be omitted.

In the CCD 16 according to the present embodiment, the imaging unit 100 and the focus detection unit 200 are arranged in the vertical direction of the photographing screen 300. Therefore, according to this, it is possible to easily detect the focus of a subject having a contrast in the vertical direction of the photographing screen 300, for example, a horizontal line.

Alternatively, for example, the imaging section 100 and the focus detection section 200 of the CCD 16 may be arranged in the horizontal direction of the photographing screen 300. In such an arrangement, it is possible to easily detect the focus of an object having a contrast in the horizontal direction of the photographing screen, for example, a vertical line.

The CC of the present embodiment configured as described above
The operation of the electronic imaging device to which D16 is applied will be described below. FIG. 11 is a flowchart showing a main routine of the microcomputer 31 which is a control unit in the electronic imaging apparatus. FIG. 12 shows a time chart when an imaging operation is performed in the electronic imaging apparatus.

The electronic imaging apparatus is activated by, for example, turning on a main power switch or starting power supply to an electric circuit including the microcomputer 31 by inserting a battery. ROM3
The sequence program stored in advance in 1b is executed.

First, in step S101, initialization of each electric circuit block of the electronic imaging apparatus is performed.

Next, in step S102, the microcomputer 31 detects the state of the 1RSW 47 and confirms whether or not it has been turned on. Here, when an ON signal of the 1RSW 47 generated by operating a predetermined operation member is confirmed, the process proceeds to step S103.

If the ON signal of the 1RSW 47 is not confirmed, the process proceeds to step S105.
In this step S105, an image pickup operation for a series of photometry such as an accumulation (exposure) operation and a readout operation in the image pickup section 100 of the CCD 16 (hereinafter simply referred to as a photometry operation).
Is performed, and the process proceeds to the next step S106.

Next, in step S106, the CCD 16 (the imaging unit 10) output from the video signal processing unit 42
In response to the image signal acquired in step (0), the photometry / exposure calculation unit 45 executes predetermined photometry and exposure calculation processing. In this way, information required during the main exposure operation (when performing image recording), that is, exposure information appropriate for the subject, for example, an aperture value of the aperture unit 12, an electronic shutter speed value of the CCD 16, and the like are calculated.

That is, when the electronic imaging apparatus is started, the photometric operation is always started, and the photometric operation is continuously executed (see reference numeral [2] in FIG. 12). At this time, as shown by reference numeral [3] in FIG.
2 is open.

On the other hand, in the above-mentioned step S102,
When it is confirmed that the 1RSW 47 has been turned on (see reference numeral [1] in FIG. 12), the next step S103 is performed.
, The accumulation operation of the focus detection unit 200 of the CCD 16 is performed (exposure for AF; see reference numeral [4] in FIG. 12), and a predetermined image signal is read out using the focus detection unit 200. In the next step S104, the readout is performed. A predetermined focus detection calculation is performed based on the obtained image signal (see reference numeral [5] in FIG. 12). Note that the predetermined focus detection calculation executed here is based on a general procedure executed by an AF unit or the like of a conventional electronic imaging device or the like, and a detailed description thereof will be omitted.

Next, in step S107, it is determined whether the result of the focus detection calculation executed in step S104 is in a focused state or an out-of-focus state. Here, when it is determined that the subject is in focus,
The process proceeds to step S109, and if it is determined that the subject is out of focus, the process proceeds to step S108.

In step S108, the amount of movement of the focusing lens 11a for bringing the lens into focus is calculated based on the result of the focus detection calculation in step S104, and the lens 11a is driven (reference numeral [FIG. 12]). 7]). After that, the process returns to step S102, and the same AF operation is repeated thereafter.

On the other hand, in step S109, 2R
The state of SW48 is detected to confirm whether or not the switch is on. Here, when it is confirmed that the 2RSW 48 is in the ON state (see reference numeral [6] in FIG. 12), the process proceeds to the next step S110, and the 2RSW 4 is turned on.
If it is confirmed that 8 is in the off state, the process returns to step S102, and the subsequent sequence is continuously executed while waiting for the 2RSW 48 to be in the on state.

In the processing after step S110, a so-called main exposure operation (see reference numeral [8] in FIG. 12) is executed. First, in step S110, the microcomputer 31
Controls the aperture unit 12 via the aperture drive unit 33 to drive the aperture unit to the exposure aperture value calculated in step S106 (aperture control process; see reference numeral [9] in FIG. 12).

Next, in step S111, the CCD
The control unit 43 controls the CCD 16 to switch the charge sweeping signal SUB to the off state to start the accumulation operation by the CCD 16, and performs the exposure (main exposure) using the electronic shutter speed value calculated by the exposure calculation processing in step S106 described above. The operation is performed (see reference numeral [8] in FIG. 12). Here, the electronic shutter is a CCD control unit 43
, A charge transfer pulse TGP is generated at a predetermined timing according to the electronic shutter speed value, and the charge stored in the photodiode 101 is transferred to the vertical shift register 103.

In the next step S112, in order to prevent noise components such as so-called smear from being mixed into the image signal to be acquired, the diaphragm unit 12 is closed via the diaphragm driving unit 33. And the diaphragm unit 12 is completely closed (see reference numeral [10] in FIG. 12). As a result, the light receiving surface of the CCD 16 is in a light shielding state.

Subsequently, in step S113, CC
The CCD controller 43 outputs the image read signal DCLK to the CCD 16 while keeping the light-shielded state of D16.
Then, the video signal processing unit 42 outputs the image signal (CCD signal) of the imaging unit 100 which is output in synchronization with the signal DCLK.
Is read out after A / D conversion (see reference numeral [11] in FIG. 12).

Next, in step S114, the microcomputer 31 transmits a predetermined aperture opening command to open the aperture section 12 via the aperture driving section 33, drives the aperture section 12, and opens the aperture section. Return to the state (see reference numeral [12] in FIG. 12).

Further, in step S115, the video signal processing unit 42 performs a predetermined process for optimizing the recording of the image signal acquired by the CCD 16, for example, a compression process and the like. 86 is stored in a predetermined area (see reference numeral [12] in FIG. 12). Thereafter, a series of operations is completed, the process returns to the above-described step S102, and the subsequent processes are similarly repeated.

As described above, according to the first embodiment, the pupil-divided minute lens group (second micro-lens array 206) and the pair of pupil-divided light beams that receive the pupil-divided light beam are provided on the same chip as the image pickup device (CCD 16). Since the light receiving element group (photodiodes 201a and 201b) is formed and the focus detection operation is performed based on the output signal of the light receiving element group, cost reduction and cost saving can be achieved without adding new components. It is possible to realize a focus adjustment device that contributes to space and is faster and more accurate.

In the above-described first embodiment,
The color filter 137 is arranged only on the front surface of the imaging unit 100, while the color filter is not arranged on the front surface of the focus detection unit 200. Therefore, in the case of such a configuration, the burden of the manufacturing cost may increase in the process of manufacturing the imaging device.

Therefore, in the following second embodiment of the present invention, a color filter is arranged also on the front surface of the focus detecting section 200. FIG. 13 is a diagram illustrating an image sensor according to the second embodiment of the present invention, and is a diagram illustrating a configuration of a color filter arranged on the front surface of the image sensor.

The arrangement of the color elements of the color filter 137 in the image pickup device of the first embodiment is the Bayer arrangement as described above (see FIG. 9).

In the present embodiment, as shown in FIG.
And the photodiodes 101a and 201b of the focus detection unit 200 as one unit, and color filters of the same color element are arranged.

As described above, in the present embodiment, the configuration of the color filters arranged on the front surface of the image pickup device is slightly different, and the other configurations are exactly the same as those of the above-described first embodiment. It is.

When the focus detection calculation is performed in the image pickup device configured as described above, only the pixel signal of the photodiode corresponding to the same color filter of the focus detection unit 200 is used for the focus detection calculation. Control.

In such a case, the detection pitch becomes large, but on the other hand, for each color (R · G
By performing the calculation three times in B), three types of calculation results can be obtained. Therefore, by performing predetermined arithmetic processing such as averaging processing and weighting processing on the three types of arithmetic results obtained in this way, it is possible to prevent deterioration in focus detection accuracy.

In the image pickup device of the first embodiment, the image pickup section 1 of the CCD 16 is used during the photographing operation.
Only the output signal from 00 is handled as an image signal. However, in the image sensor according to the second embodiment, the output signal of the focus detection unit 200 is also used as a video signal during a shooting operation.

More specifically, when an electronic image pickup apparatus using the image pickup device of the present embodiment performs a photographing operation, in addition to the accumulation operation by the photodiode 101 of the image pickup unit 100, Diode 201a
-The accumulation operation of 201b is also performed. At this time, the pair of photodiodes 201a and 201a
1b is subjected to an addition process,
Processed as a pair of pixel signals.

FIG. 14 is a flowchart showing the main exposure processing operation of the video signal processing section and the CCD control section in the electronic image pickup apparatus using the image pickup device of the present embodiment. With reference to FIG. 14, the operation of the present imaging element at the time of a shooting operation (exposure operation) will be described. The sequence of this main exposure is
This corresponds to step S111 in FIG.

First, in step S201, a predetermined accumulation operation is performed using the imaging unit 100 and the focus detection unit 200.

Next, in step S202, after the output image signals of the imaging unit 100 and the focus detection unit 200 are A / D converted and read out, the process proceeds to the next step S203, and in this step S203, the focus detection unit 200
A predetermined addition process is performed on a pair of pixel signals corresponding to the photodiodes 201a and 210b.

Subsequently, in step S204, a predetermined video signal is generated by using both the image signal of the imaging section 100 and the image signal after the addition processing of the focus detection section 200. Then, a series of processing ends (return).

Here, the photodiode 20 of the image pickup unit 100 is used by using the image signal of the photodiode 101.
The correction processing of the added image signal of 1a and 201b is performed,
A predetermined video signal may be generated.

For the video signal generation processing, for example, for any of the photodiodes 201a and 201b, the interpolation video signal obtained by interpolating the pixel signals of the four photodiodes 101 surrounding the photodiodes 201a and 201b, May be compared and the one with higher reliability may be adopted, or both may be averaged, and the processing result may be used as a video signal.

The photodiodes 201a and 201
Regarding the addition processing of b, A
In addition to the processing means for adding the digital image data after executing the / D conversion, for example, the vertical shift register 2
There is a processing means for adding as a charge signal inside the internal circuit 03.

According to the present embodiment configured as described above, since the color filters are arranged on the entire front side of each light receiving element constituting the image pickup device, the image pickup of the first embodiment described above is performed. Since the manufacturing process can be simplified without deteriorating the focus detection accuracy compared to the element,
This can easily contribute to a reduction in manufacturing cost.

Further, by disposing the color filters also on the front surface of the focus detecting section 200, the corresponding photodiodes 201a and 201b can be used for the photographing operation. Therefore, according to this, it is possible to easily improve the resolution in the horizontal direction about twice.

Incidentally, in the image pickup device of the first embodiment, as described above, the image pickup unit 100 and the focus detection unit 20 are used.
The arrangement of 0 is arranged in the vertical direction or the horizontal direction of the photographing screen 300 (see FIG. 10). Thus, the configuration is such that focus detection can be performed on a subject having contrast in one of the vertical and horizontal directions of the photographing screen 300, for example, only one of a horizontal line and a vertical line. Therefore, if the configuration is such that the change in contrast in the vertical and horizontal directions can be detected, it becomes even more convenient.
The third embodiment shown below takes this into consideration.

FIG. 15 is an enlarged view of a main part of an image pickup device according to a third embodiment of the present invention. The imaging device (CCD) of the present embodiment includes an imaging unit that performs imaging and a focus detection unit that performs focus detection, as in the first embodiment. The imaging unit is a light receiving element for imaging. A certain photodiode 401 and this photodiode 401
And a vertical shift register 403a for sequentially transferring the charges accumulated in the vertical direction in the vertical direction.

The focus detecting section includes a pair of photodiodes 40 which are light receiving elements used for detecting the focus of a horizontal line.
1a and 401b and a pair of photodiodes 401
a, a vertical shift register 403b for sequentially transferring the charges accumulated in the vertical direction in the vertical direction, a pair of photodiodes 501a, 501b as light receiving elements used for focus detection of a vertical line, and the pair of photodiodes 501a. A vertical shift register 403c and the like which sequentially transfer the charges accumulated in the 501b in the vertical direction.

Then, each of the above-described photodiodes 401
In front of the light receiving surfaces of 401a, 401b, 501a, and 501b, a microlens array 406 for forming a subject image on the light receiving surfaces of these five photodiodes is arranged. A unit including the focus detection unit and the microlens array 406 is configured as one unit (one pixel).

A pair of photodiodes 401a and 401b for detecting the focus of the horizontal line are based on an image signal obtained by a similar pair of photodiodes arrayed in the vertical direction of the photographing screen 300 (see FIG. 10). It is used to detect a vertical image shift of a shooting screen.

Similarly, a pair of photodiodes 501a and 501b for focus detection of a vertical line
It is used to detect a horizontal image shift of a photographed screen based on image signals obtained by a pair of photodiodes arranged in a plurality in the horizontal direction (see FIG. 10).

The microlens array 406 has five photodiodes 401 as shown in an enlarged view of a main part in FIG.
The five parts corresponding to 401a, 401b, 501a, and 501b have a shape formed integrally, and the cross-sectional shape is as shown in the cross-sectional view of FIG.

That is, the micro lens array 406 is
For example, the first micro lens array 106 and the second micro lens array 206 in the first embodiment are equivalent to those formed integrally by a single member, and the corresponding five light receiving elements (photo Diode 4
01, 401a, 401b, 501a, and 501b) so that their optical characteristics such as curvature and focal length are different. Other configurations are substantially the same as those of the first embodiment.

The focus detection operation performed by the electronic image pickup apparatus using the image pickup device (CCD) of the present embodiment thus configured is substantially the same as that of the above-described first embodiment. In the embodiment, first, a pair of photodiodes 501a and 501b for detecting a focus of a vertical line is used to detect a horizontal image shift of a shooting screen.
The difference is that the image shift in the vertical direction of the photographing screen is detected using a and 401b.

FIG. 18 is a flowchart showing an operation when a focus detection operation is performed by an electronic image pickup apparatus using the image pickup device of this embodiment. This sequence of the focus detection calculation processing corresponds to step S104 in FIG.

First, in step S301, the photodiodes 501a and 5 are arranged in the horizontal direction of the photographing screen.
The image shift amount in the horizontal direction of the shooting screen is detected by using the image signal acquired by 01b. In this case,
A subject 31 as shown in FIG. 19, that is, a subject 31 such as a vertical line having a contrast in a horizontal direction (horizontal direction) of a photographing screen.
The operation of detecting the amount of image shift in the horizontal direction with respect to 0a is performed.

Subsequently, in step S302, a determination is made as to the detection result of the focus detection operation executed in step S301. Here, if it is determined that the focus position can be sufficiently detected based on the focus detection result, the detection result is adopted, a series of the focus detection operation sequence ends, and the process returns to the main routine. (return).

On the other hand, in step S302 described above,
Depending on the focus detection operation performed in step S301,
If the desired detection result is not obtained, step S
The process moves to step 303.

For example, with respect to a subject as shown in FIG. 20, ie, a subject 310b such as a horizontal line having a contrast in the vertical direction (vertical direction) of the photographing screen, the photodiodes 501a. Depending on 501b, a sufficient focus detection result cannot be obtained.

Accordingly, in such a case, in step S303, the operation of detecting the amount of image shift in the vertical direction of the photographic screen based on the image signals obtained by the photodiodes 401a and 401b arranged in the vertical direction of the photographic screen. Perform Then, assuming that the detection result is adopted, a sequence of the focus detection operation is ended, and the process returns to the main routine (return).

In most cases, the subject to be photographed during normal photographing is a subject 310a (FIG. 1) having a contrast in the horizontal direction (horizontal direction) of the photographing screen.
9) and a subject 310b (see FIG. 20) having a contrast in the vertical direction (vertical direction) of the photographing screen. In

In consideration of this point, in the sequence of the focus detection operation in the present embodiment, the process of detecting the amount of image shift in the horizontal direction is executed with priority as described above, and the focus position is determined by this detection process. When a detection result sufficient for the detection is obtained, the detection result is adopted to execute the automatic focusing operation.

If a desired detection result is not obtained by the first focus detection operation of the amount of image shift in the horizontal direction (step S301 in FIG. 18), the second focus detection operation is performed. A process of detecting a vertical image shift amount is executed.

As described above, according to the third embodiment, substantially the same effects as those of the first embodiment can be obtained. In addition, since the focus detection operation can be performed in both the horizontal direction and the vertical direction with respect to the shooting screen, when shooting is performed by an electronic imaging device or the like to which the focus detection operation is applied, the subject in the shooting screen is Irrespective of the contrast state or the like, a highly accurate focus detection operation can be easily performed.

Further, in the sequence of the focus detection operation, the amount of image shift in the horizontal direction is preferentially detected, so that the time lag or the like caused by the focus detection operation is smaller than that in the first embodiment. Can be reduced.

Further, in the sequence of the focus detection operation, when the focus detection operation is performed in both the horizontal direction and the vertical direction, the focus adjustment operation is performed by employing the detection result considered to be highly reliable. Since this operation is performed, a more accurate focus detection operation can be performed.

In each of the above embodiments, the CCD is taken as an example of the image pickup device.
The configuration of the present invention can be easily applied to, for example, a MOS sensor and other types of solid-state imaging devices.

[Supplementary Note] According to the above-described embodiment, an invention having the following configuration can be obtained.

(1) An image sensor that can be used in an image pickup apparatus, which includes a first light receiving element group for receiving a subject image, and a first microlens group for condensing subject light on the first light receiving element group. And pupil division of the light beam passing through the taking lens
A microlens group, and a pair of second light receiving element groups that respectively receive light beams pupil-divided by the second micro lens group and form a pair. An image sensor formed on an image sensor chip.

(2) In the imaging device described in Appendix 1, the first minute lens group and the second minute lens group are configured to have optical characteristics different from each other.

(3) In the imaging device described in Appendix 1, a color filter is arranged on the front surface of the first minute lens group, while a color filter is arranged on the front surface of the second minute lens group. Not.

(4) In the image pickup device described in Appendix 1, signal charges output from the first light receiving element group are transferred using the first charge transfer path, and the second light receiving element group is transferred. The signal charge output from the second transfer path is transferred using the second charge transfer path.

[0141]

As described above, according to the present invention, the focus detection speed can be improved without newly adding structural members such as mechanical members and optical members, and without increasing the size of the electronic image pickup apparatus. It is therefore an object of the present invention to provide an image pickup device that can realize high-precision focus adjustment function while contributing to cost reduction and space saving.

Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing components constituting a main optical system in an electronic image pickup apparatus having an image pickup device according to a first embodiment of the present invention.

FIG. 2 is a main block configuration diagram showing electrical components of the electronic imaging apparatus in FIG. 1;

FIG. 3 is a main block diagram showing a video signal processing unit and a recording unit in the electronic imaging apparatus shown in FIG. 1 and a part of a main electric circuit electrically connected thereto;

FIG. 4 is an imaging device (CCD) according to the first embodiment of the present invention.
FIG. 2 is an enlarged configuration diagram of a main part, showing a part of the configuration enlarged.

FIG. 5 is an enlarged view of a main part showing a part of a photodiode and a microlens in the imaging device (CCD) of FIG.

FIG. 6 is a diagram showing a detailed configuration of a conventional solid-state imaging device (CCD) in which an on-chip microlens is formed, and illustrates a horizontal direction (a direction orthogonal to a transfer direction of a vertical shift register) of the solid-state imaging device. Sectional view.

FIG. 7 is a diagram showing a state in which a light beam transmitted through an imaging optical system is pupil-divided by a microlens and is incident on a pair of photodiodes in the electronic imaging apparatus of FIG.

8 is a focus detection unit 200 of the imaging device (CCD) of FIG.
FIG. 3 is an optical path diagram of a light beam incident on the light source.

FIG. 9 is a diagram showing an arrangement of color elements of a color filter in the imaging device (CCD) of FIG.

FIG. 10 is a diagram showing a focus detection area with respect to a shooting screen in the electronic imaging apparatus of FIG. 1;

FIG. 11 is a flowchart showing main operations of a control unit in the electronic imaging apparatus of FIG. 1;

FIG. 12 is a time chart when an imaging operation is performed in the electronic imaging apparatus of FIG. 1;

FIG. 13 shows an image sensor according to a second embodiment of the present invention;
FIG. 2 is a diagram illustrating a configuration of a color filter arranged on a front surface of an image sensor.

14 is a flowchart showing a main exposure processing operation of a video signal processing unit and a CCD control unit in the imaging device of FIG.

FIG. 15 is a main part enlarged view showing a main part of an image sensor according to a third embodiment of the present invention in an enlarged manner.

FIG. 16 is an enlarged view of a main part, showing only one unit in the image sensor of FIG. 15;

FIG. 17 is a longitudinal sectional view taken along the line AA of FIG. 16;

FIG. 18 is a flowchart illustrating an operation when a focus detection operation is performed by an electronic imaging device using the imaging device in FIG. 15;

FIG. 19 is a diagram illustrating an example of a subject having a contrast in a horizontal direction (horizontal direction) of a shooting screen.

FIG. 20 is a diagram showing an example of a subject having a contrast in a vertical direction (vertical direction) of a shooting screen.

[Explanation of symbols]

11: Photographing optical system 13: Beam splitter (divided optical system) 14: Infrared light cut filter (imaging system) 15: Optical low-pass filter (LPF; finder optical system) 16: Imaging device (CCD) 20 Finder optical system 31 Microcomputer (control means) 100 Imaging unit 101 401 Photodiode (for imaging) 102 202 Transfer gate 103 203 403 a 403 b 403 c Vertical shift register 104 ·······································································································································································;・ 401a ・ 401b ・ 501a ・
501b Photodiode (for focus detection)

Continuation of the front page (72) Inventor Junichi Ito 2-43-2 Hatagaya, Shibuya-ku, Tokyo F-term in Olympus Optical Co., Ltd. (reference) 2H011 AA01 AA02 AA03 BA33 2H051 AA01 AA07 AA08 BA44 BA47 CB09 CB11 CB13 CB14 CB20 DA03 DA11 DA31 EB02 GA09 5C022 AA13 AB27 AB28 AC42

Claims (3)

[Claims] 1. An image pickup device for photoelectrically converting an optical image transmitted through a photographing optical system and formed on a light receiving surface, wherein a first micro lens array two-dimensionally arranged with a focal position near the light receiving surface. And a second microlens array; a first light receiving element group disposed near a focal position of the first micro lens array, each of which has a single light receiving element that outputs a first video signal; A second light-receiving element group disposed near the focal position of the microlens array and configured as a pair of light-receiving elements that respectively output a second video signal. 2. The imaging device according to claim 1, wherein a color filter arranged in a Bayer array is interposed at least in an optical path of the first micro lens array. 3. The imaging device according to claim 1, wherein the first micro lens array and the second micro lens array have different focal lengths and / or curvatures.