Solid-state image pickup device and image pickup device

To acquire a color image. A solid-state image pickup device according to an embodiment includes a plurality of light receiving portions, each of which receives light of a specific wavelength to generate an electric charge corresponding to an amount of the received light, a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions, a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. 371 and claims the benefit of PCT Application No. PCT/JP2019/035649 having an international filing date of 11 Sep. 2019, which designated the United States, which PCT application claimed the benefit of Japanese Priority Patent Application JP 2018-187784 filed on 2 Oct. 2018, the entire disclosures of each of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a solid-state image pickup device and an image pickup device.

BACKGROUND ART

In the past, a synchronous solid-state image pickup device that captures image data (frame) in synchronization with a synchronization signal such as a vertical synchronization signal has been used in an image pickup device, etc. In this general synchronous solid-state image pickup device, image data can be acquired only at every cycle of the synchronization signal (for example, 1/60 seconds). Thus, it is difficult to deal with a case requesting faster processing in a field related to traffic, a robot, etc. Therefore, an asynchronous solid-state image pickup device has been proposed in which a detection circuit for detecting in real time that an amount of the received light exceeds a threshold value as an address event is provided for each pixel. The asynchronous solid-state image pickup device that detects an address event for each pixel is also referred to as a dynamic vision sensor (DVS).

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

However, in a DVS in the related art, a wavelength selection element such as a color filter has not been mounted due to a structural characteristic of asynchronously reading a pixel signal from each pixel. For this reason, there has been a problem that a color image may not be acquired by the DVS.

In this regard, the present disclosure proposes a solid-state image pickup device and an image pickup device capable of acquiring a color image.

Solution to Problem

According to an embodiment of the present disclosure, there is provided a solid-state image pickup device including a plurality of light receiving portions, each of which receives light of a specific wavelength to generate an electric charge corresponding to an amount of the received light, a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions, a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to drawings. Note that in embodiments below, a repeated description will be omitted by assigning the same reference numeral to the same part.

In addition, the present disclosure will be described according to an item order shown below.

2. First Embodiment2.1 Configuration example of image pickup device2.2 Configuration example of solid-state image pickup device2.2.1 Stacked configuration example of solid-state image pickup device2.2.2 Functional configuration example of solid-state image pickup device2.3 Configuration example of pixel array portion2.4 Example of pixel block2.4.1 Bayer array2.4.2 X-Trans (registered trademark) type array2.4.3 Quad Bayer array2.4.4 Other2.5 Detection of firing of address event2.6 Configuration example of pixel block2.7 Configuration example of address event detector2.8 Configuration example of current-voltage conversion unit2.9 Configuration example of subtractor and quantizer2.10 Configuration example of column ADC2.11 Operation example of solid-state image pickup device2.11.1 Timing chart2.11.2 Flowchart2.12 Effects

3. Second Embodiment3.1 Detection of firing of address event3.2 Configuration example of pixel block3.3 Operation example of solid-state image pickup device3.4 Effects

4. Third Embodiment4.1 Example of pixel block4.2 Effects

5. Fourth Embodiment5.1 Example of pixel block5.2 Effects

A general dynamic vision sensor (DVS) adopts a so-called event-driven type driving method of detecting presence or absence of firing of an address event for each unit pixel, and reading a pixel signal from a unit pixel where an address event fires in a case where firing of the address event is detected.

Note that the unit pixel in this description is a minimum unit of a pixel including one photoelectric conversion element (also referred to as a light receiving element), and corresponds to, for example, each dot in image data read from an image sensor. In addition, the address event is an event occurring for each address allocated to each of a plurality of unit pixels arrayed in a 2D lattice pattern, and corresponds to, for example, an event in which a current value of a photoelectric current based on an electric charge generated in the photoelectric conversion element or a change amount thereof exceeds a certain threshold value, etc.

In such an event-driven type DVS, reading for each unit pixel is asynchronously executed unlike a general image sensor such as a complementary metal-oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor. For this reason, for example, when a wavelength selection element such as a color filter is merely mounted on the DVS to acquire a color image, in a case where a color is reconstructed on the basis of wavelength components used for reconstruction of the color, for example, three primary colors of RGB, synchronous reading of pixel signals of a wavelength component of read (R), a wavelength component of green (G), and a wavelength component of blue (B) is not ensured, and each of the pixel signals is read at an irregular timing. As a result, a temporal shift or a spatial shift occurs in the wavelength components used for reconstruction of the color, making it difficult to reconstruct a correct color.

Note that for example, the temporal shift refers to a shift on a time axis due to a timing shift caused by asynchronous reading of pixel signals of all wavelength components used for reconstruction of the color. In addition, for example, the spatial shift refers to a shift in a color space resulting from difficulty in determining a white level for white balance adjustment on the basis of the pixel signals of all wavelength components used for reconstruction of the color.

Therefore, in embodiments below, a solid-state image pickup device and an image pickup device capable of acquiring a color image in which a color is correctly reconstructed will be described in detail with some examples.

In addition, in some of the embodiments below, a solid-state image pickup device and an image pickup device capable of reconstructing polarization information of incident light instead of reconstruction of a color or together with reconstruction of a color will be described in detail with some examples.

2. First Embodiment

First, a solid-state image pickup device and an image pickup device according to a first embodiment of the present disclosure will be described in detail with reference to drawings.

2.1 Configuration Example of Image Pickup Device

FIG. 1is a block diagram illustrating a schematic configuration example of the solid-state image pickup device and the image pickup device according to the first embodiment. As illustrated inFIG. 1, for example, the image pickup device100includes an imaging lens110, a solid-state image pickup device200, a recording unit120, and a controller130. A camera mounted on an industrial robot, an in-vehicle camera, etc. is assumed as the image pickup device100.

The imaging lens110concentrates incident light and forms an image on a light receiving surface of the solid-state image pickup device200. The light receiving surface refers to a surface on which photoelectric conversion elements (also referred to as light receiving elements) in the solid-state image pickup device200are arrayed. The solid-state image pickup device200photo-electrically converts incident light to generate image data. In addition, the solid-state image pickup device200performs predetermined signal processing such as noise removal or white balance adjustment on the generated image data. A result obtained by this signal processing and a detection signal indicating presence or absence of firing of the address event are output to the recording unit120via a signal line209. Note that a method of generating the detection signal indicating presence or absence of firing of the address event will be described later.

The recording unit120includes, for example, a flash memory, a dynamic random access memory (DRAM), a static random access memory (SRAM), etc., and records data input from the solid-state image pickup device200.

The controller130includes, for example, a central processing unit (CPU), etc., and outputs various instructions via a signal line139, thereby controlling each unit in the image pickup device100such as the solid-state image pickup device200.

2.2 Configuration Example of Solid-State Image Pickup Device

Next, a configuration example of the solid-state image pickup device200will be described in detail with reference to drawings.

2.2.1 Stacked Configuration Example of Solid-State Image Pickup Device

FIG. 2is a diagram illustrating a stacked structure example of the solid-state image pickup device according to the first embodiment. As illustrated inFIG. 2, the solid-state image pickup device200has a structure in which a light receiving chip201and a detection chip202are vertically stacked. As bonding of the light receiving chip201and the detection chip202, for example, it is possible to use so-called direct bonding in which respective bonding surfaces are planarized and pasted together by electron force. However, the present disclosure is not limited thereto. For example, it is possible to use so-called Cu—Cu bonding in which copper (Cu) electrode pads formed on bonding surfaces thereof are bonded to each other, bump bonding, etc.

In addition, the light receiving chip201and the detection chip202are electrically connected via, for example, a connecting portion such as a through-silicon via (TSV) penetrating a semiconductor substrate. For connection using the TSV, for example, it is possible to adopt a so-called twin TSV system in which two TSVs, that is, a TSV provided on the light receiving chip201and a TSV provided from the light receiving chip201to the detection chip202are connected on an external surface of the chip, a so-called shared TSV system in which the chips are connected by a TSV penetrating therethrough from the light receiving chip201to the detection chip202, and the like.

However, in the case of using Cu—Cu bonding or bump bonding for bonding the light receiving chip201and the detection chip202, the chips are electrically connected through a Cu—Cu bonding portion or a bump bonding portion.

2.2.2 Functional Configuration Example of Solid-State Image Pickup Device

FIG. 3is a block diagram illustrating a functional configuration example of the solid-state image pickup device according to the first embodiment. As illustrated inFIG. 3, the solid-state image pickup device200includes a driving circuit211, a signal processing unit212, an arbiter213, a column ADC220, and a pixel array portion300.

In the pixel array portion300, a plurality of unit pixels is arrayed in a 2D lattice pattern. As will be described in detail later, for example, a unit pixel includes a photoelectric conversion element such as a photodiode and a circuit (hereinafter referred to as a pixel circuit or a pixel signal generator) for reading an electric charge generated by photoelectric conversion from the photoelectric conversion element. Here, the pixel circuit can be shared by a plurality of photoelectric conversion elements. In this case, each unit pixel includes one photoelectric conversion element and the shared pixel circuit.

A plurality of unit pixels arrayed in the 2D lattice pattern in the pixel array portion300is grouped into a plurality of pixel blocks, each of which includes a predetermined number of unit pixels. Hereinafter, a set of unit pixels or pixel blocks arrayed in a horizontal direction is referred to as “row”, and a set of unit pixels or pixel blocks arrayed in a direction perpendicular to the row is referred to as “column”.

Each unit pixel generates an electric charge corresponding to the amount of light received by the photoelectric conversion element. Each pixel block detects presence or absence of firing of an address event on the basis of whether or not a current value of a current resulting from an electric charge generated in any one of unit pixels belonging to the pixel block (hereinafter referred to as a photoelectric current) or a change amount thereof exceeds a predetermined threshold value. Then, when the address event fires, each pixel block outputs a request for reading a pixel signal having a voltage value corresponding to the amount of light received by the photoelectric conversion element from each unit pixel belonging to the pixel block to the arbiter213.

The driving circuit211drives each of the unit pixels to output a pixel signal from each unit pixel to the column ADC220.

The arbiter213arbitrates a request from each pixel block and transmits a predetermined response to a pixel block issuing the request on the basis of an arbitration result. Upon receiving this response, the pixel block supplies a detection signal indicating presence or absence of firing of the address event (hereinafter, simply referred to as an address event detection signal) to the driving circuit211and the signal processing unit212.

For each column of a pixel block, the column ADC220converts an analog pixel signal from the column into a digital signal. Then, the column ADC220supplies the digital signal generated by conversion to the signal processing unit212.

The signal processing unit212performs predetermined signal processing such as correlated double sampling (CDS) processing (noise removal) or white balance adjustment on the digital signal from the column ADC220. Then, the signal processing unit212supplies a result of the signal processing and the address event detection signal to the recording unit120via the signal line209.

2.3 Configuration Example of Pixel Array Portion

Next, a configuration example of the pixel array portion300will be described.FIG. 4is a block diagram illustrating a schematic configuration example of the pixel array portion according to the first embodiment. As illustrated inFIG. 4, a plurality of unit pixels in the pixel array portion300is grouped into a plurality of pixel blocks310. Each of the pixel blocks310includes a plurality of unit pixels arrayed in I rows×J columns (I and J are positive integers).

Each pixel block310includes a pixel signal generator320, a plurality of light receiving portions330of I rows×J columns, and an address event detector400. The pixel signal generator320and the address event detector400are shared by the plurality of light receiving portions330in the pixel block310. Therefore, each unit pixel includes one light receiving unit330and the shared pixel signal generator320. Coordinates of the respective unit pixels conform to coordinates of the light receiving portions330arrayed in the 2D lattice pattern on the light receiving surface of the solid-state image pickup device200.

One vertical signal line VSL is wired in a column of one pixel block310. Therefore, when the number of columns of the pixel blocks310is set to m (m is a positive integer), m vertical signal lines VSL are arrayed in the pixel array portion300.

The light receiving portion330is a photoelectric conversion element that generates a photoelectric current by photoelectric conversion of incident light. According to the control of the driving circuit211, the light receiving portion330supplies the photoelectric current generated by photoelectric conversion to either the pixel signal generator320or the address event detector400.

The pixel signal generator320generates a signal having a voltage value corresponding to an electric charge amount of the photoelectric current supplied from the light receiving portion330as a pixel signal SIG. The pixel signal generator320supplies the generated pixel signal SIG to the column ADC220via the vertical signal line VSL.

The address event detector400detects presence or absence of firing of the address event on the basis of whether or not a current value of the photoelectric current supplied from the light receiving portion330in the same pixel block310or a change amount thereof exceeds a predetermined threshold value. For example, this address event includes an ON event indicating that the change amount exceeds an upper limit threshold and an OFF event indicating that the change amount falls below a lower limit threshold. In addition, for example, the address event detection signal includes one bit indicating a detection result of the ON event and one bit indicating a detection result of the OFF event. Note that the address event detector400may be configured to detect either the ON event or the OFF event.

When the address event fires, the address event detector400supplies a request to the arbiter213to request transmission of the detection signal. Further, upon receiving a response to the request from the arbiter213, the address event detector400supplies the detection signal to the driving circuit211and the signal processing unit212.

The driving circuit211to which the detection signal is supplied executes reading for each unit pixel belonging to the pixel block310that includes the address event detector400supplying the detection signal. By this reading, a pixel signal SIG having an analog value is input to the column ADC220in order from each unit pixel in the pixel block310to be read.

2.4 Example of Pixel Block

In the configuration illustrated inFIG. 4, for example, the pixel block310is configured by a combination of unit pixels that receive wavelength components used to reconstruct a color. For example, in the case of reconstructing a color on the basis of the three primary colors of RGB, the pixel block310is configured by a combination of a unit pixel receiving red (R) light, a unit pixel receiving green (G) light, and a unit pixel receiving blue (B) light.

Therefore, in the present embodiment, for example, the plurality of unit pixels arrayed in the 2D lattice pattern in the pixel array portion300is grouped into a plurality of pixel blocks310on the basis of array of wavelength selection elements (for example, color filters) provided for the light receiving portion330of each unit pixel (hereinafter referred to as a color filter array).

Various arrays, for example, a Bayer array of 2×2 pixels, a color filter array of 3×3 pixels adopted for X-Trans (registered trademark) CMOS sensor (hereinafter referred to as an X-Trans (registered trademark) type array), a Quad Bayer array of 4×4 pixels (also referred to as a quadratic array), etc. are present as the color filter array.

Therefore, hereinafter, the pixel block310corresponding to the case of adopting a representative color filter array will be described with some examples.

FIG. 5is a schematic diagram illustrating a configuration example of the pixel block corresponding to the case of adopting the Bayer array for the color filter array. As illustrated inFIG. 5, in the case of adopting the Bayer array for the color filter array, one pixel block310A includes a basic pattern (hereinafter referred to as a unit pattern) having a total of four unit pixels of 2×2 pixels which is a unit of repetition in the Bayer array. Therefore, for example, each pixel block310A according to this example includes a light receiving portion330R having a color filter of red (R) color, a light receiving portion330Gr having a color filter of green (Gr) color, a light receiving portion330Gb having a color filter of green (Gb) color, and a light receiving portion330B having a color filter of blue (B) color.

FIG. 6is a schematic diagram illustrating a configuration example of the pixel block corresponding to the case of adopting the X-Trans (registered trademark) type array for the color filter array. As illustrated inFIG. 6, in this example, one pixel block310B includes a basic pattern (hereinafter referred to as a unit pattern) having a total of nine unit pixels of 3×3 pixels which is a unit of repetition in the X-Trans (registered trademark) type array. Therefore, for example, each pixel block310B according to this example includes five light receiving portions330G having color filters of green (G) color arrayed along two diagonal lines of a rectangular region forming the unit pattern, two light receiving portions330R having color filters of red (R) color point-symmetrically arrayed with respect to the light receiving portion330G located at a center of the rectangular region as a central axis, and two light receiving portions330B having color filters of blue (B) color point-symmetrically arrayed with respect to the light receiving portion330G located at the center of the rectangular region as a central axis in a same manner.

2.4.3 Quad Bayer Array

FIG. 7is a schematic diagram illustrating a configuration example of the pixel block corresponding to the case of adopting the Quad Bayer array for the color filter array. As illustrated inFIG. 7, in the case of adopting the Quad Bayer array for the color filter array, one pixel block310C includes a basic pattern (hereinafter referred to as a unit pattern) having a total of sixteen unit pixels of 4×4 pixels which is a unit of repetition in the Quad Bayer array. Therefore, for example, each pixel block310C according to this example includes a total of four light receiving portions330R of 2×2 pixels having color filters of red (R) color, a total of four light receiving portions330Gr of 2×2 pixels having color filters of green (Gr) color, a total of four light receiving portions330Gb of 2×2 pixels having color filters of green (Gb) color, and a total of four light receiving portions330B of 2×2 pixels having color filters of blue (B) color.

2.4.4 Other

FIG. 8is a schematic diagram illustrating a configuration example of the pixel block in a case where the unit pixel does not include a color filter. For example, there are cases in which the solid-state image pickup device200does not include a color filter such as the case of having a structure in which the light receiving portions330for the three respective primary colors of RGB are arrayed along an incident direction of light (vertical product). As illustrated inFIG. 8, such as case has a structure in which a light receiving portion330G for receiving light of green (G) color, a light receiving portion330B for receiving light of blue (B) color, and a light receiving portion330R for receiving light of red (R) color are provided in one pixel area330G/B/R. Therefore, in such a case, in the present embodiment, a pixel block310D includes three light receiving portion330G,330B, and330R provided in one pixel area330G/B/R.

As described above, in a case where the color filter is provided for the light receiving portion330, a set of unit pixels included in a unit pattern of repetition in the color filter array can be used as a combination of unit pixels receiving wavelength components used to reconstruct a color. In addition, in a case where no color filter is provided, it is possible to use a set of unit pixels for each color component provided in one pixel area330G/B/R.

However, the present disclosure is not limited thereto, and one pixel block310may include a set of unit pixels provided in a plurality of unit patterns or a plurality of pixel areas330G/B/R. In addition, without being restricted by a unit pattern, it is possible to group a plurality of unit pixels in the pixel array portion300into a plurality of pixel blocks310so that each pixel block310includes a unit pixel used to reconstruct a color.

Note that in a structure in which the unit pixel includes no color filter, that is, in a structure in which the light receiving portions330are arrayed along an incident direction of light (vertical product), there is a case where a photoelectric conversion element333(seeFIG. 11) in one or more of a plurality of light receiving portions330is formed using an organic material. However, in such a case, it is possible to have a structure in which a light receiving portion330having the photoelectric conversion element333formed using the organic material does not include a transfer transistor331(seeFIG. 11) described later. Therefore, in such a case, the light receiving portion330having the photoelectric conversion element333formed using the organic material and a light receiving portion330having a photoelectric conversion element333formed in a semiconductor layer may be grouped into different pixel blocks310.

2.5 Detection of Firing of Address Event

In the above configuration, in the present embodiment, firing of an address event is detected for each unit pixel, and a pixel signal SIG is read from all unit pixels belonging to a pixel block310that includes a unit pixel from which firing of the address event is detected. Note that in the following description, for the sake of simplicity, an example is given for a case where the Bayer array is adopted as the color filter array, and each pixel block310(corresponding to the pixel block310A) includes a total of four light receiving portions330R,330Gr,330Gb, and330B of 2×2 pixels included in a unit pattern thereof.

FIG. 9andFIG. 10are schematic diagrams illustrating an example of a configuration of detecting an address event according to the present embodiment. As illustrated inFIG. 9, each of the plurality of light receiving portions330R,330Gr,330Gb, and330B included in the pixel block310has the light receiving portion330and a color filter314R,314Gr,314Gb, or314B. In addition, in the present embodiment, an individual address event detector400R,400Gr,400Gb, or400B is provided for each of the plurality of light receiving portions330R,330Gr,330Gb, and330B. That is, in the present embodiment, the address event detector400inFIG. 4includes individual address event detectors400R,400Gr,400Gb, and400B provided for each of the light receiving portions330R,330Gr,330Gb, and330B.

As illustrated inFIG. 9andFIG. 10, a photoelectric current output from each of the light receiving portions330R,330Gr,330Gb, and330B is input to the corresponding address event detector400R,400Gr,400Gb, or400B. In a case where a current value of the photoelectric current input from the corresponding light receiving portion330R,330Gr,330Gb, or330B or a change amount thereof exceeds a predetermined threshold value, each of the address event detectors400R,400Gr,400Gb, and400B outputs a request for requesting reading of the pixel signal SIG.

Outputs of the address event detectors400R,400Gr,400Gb, and400B are integrated by an integration unit150. Therefore, a request output from at least one of the address event detectors400R,400Gr,400Gb, and400B is input to the arbiter213as a request common to the address event detectors400R,400Gr,400Gb, and400B, that is, a request in units of pixel blocks. As described above, in the present embodiment, in a case where a current value of a photoelectric current output by at least one of the light receiving portions330R,330Gr,330Gb, and330B included in the pixel block310or a change amount thereof exceeds a predetermined threshold value, a request for reading a pixel signal SIG from each of the four unit pixels belonging to the pixel block310is input to the arbiter213.

2.6 Configuration Example of Pixel Block

Next, a configuration example of the pixel block will be described.FIG. 11is a circuit diagram illustrating a schematic configuration example of the pixel block according to the first embodiment. As illustrated inFIG. 11, in the pixel block310, the pixel signal generator320includes a reset transistor321, an amplification transistor322, a selection transistor323, and a floating diffusion layer324. Outputs of the plurality of light receiving portions330R,330Gr,330Gb, and330B included in the pixel block310are connected to the address event detectors400R,400Gr,400Gb, and400B individually provided for the respective light receiving portions.

Each of the light receiving portions330R,330Gr,330Gb, and330B includes the transfer transistor331, an overflow gate (OFG) transistor332, and the photoelectric conversion element333. When the number of pixels in the pixel block310is set to N (N is a positive integer), N transfer transistors331, N OFG transistors332, and N photoelectric conversion elements333(in this example, N=4) are disposed in each pixel block310.

In each pixel block310, a transfer signal TRG-R is supplied from the driving circuit211to a gate of the transfer transistor331of the light receiving portion330R, and a control signal OFG-R is supplied from the driving circuit211to a gate of the OFG transistor332. In addition, a transfer signal TRG-Gr is supplied from the driving circuit211to a gate of a transfer transistor331of the light receiving portion330Gr, and a control signal OFG-Gr is supplied from the driving circuit211to the gate of the OFG transistor332. Further, a transfer signal TRG-Gb is supplied from the driving circuit211to a gate of a transfer transistor331of the light receiving portion330Gb, and a control signal OFG-Gb is supplied from the driving circuit211to the gate of the OFG transistor332. Furthermore, a transfer signal TRGB is supplied from the driving circuit211to a gate of a transfer transistor331of the light receiving portion330B, and a control signal OFG-B is supplied from the driving circuit211to the gate of the OFG transistor332. Hereinafter, in a case where the transfer signals TRG-R, TRG-Gr, TRG-Gb, and TRG-B are not distinguished, a sign thereof is set to TRG. In a similar manner, in a case where the control signals OFG-R, OFG-Gr, PFG-Gb, and OFG-B are not distinguished, a sign thereof is set to TRG.

Each of the reset transistor321, the amplification transistor322, and the selection transistor323is configured using, for example, an N-type metal-oxide-semiconductor (MOS) transistor. In a similar manner, the transfer transistor331and the OFG transistor332are formed using, for example, N-type MOS transistors.

The photoelectric conversion element333of each of the light receiving portions330R,330Gr,330Gb, and330B is disposed in the light receiving chip201. In addition, for example, an element other than the photoelectric conversion element333in each of the light receiving portions330R,330Gr,330Gb, and330B is disposed in the detection chip202.

In each of the light receiving portions330R,330Gr,330Gb, and330B, the photoelectric conversion element333photo-electrically converts incident light to generate an electric charge. The transfer transistor331transfers the electric charge from the corresponding photoelectric conversion element333to the floating diffusion layer324according to the transfer signal TRG. The OFG transistor332supplies the electric signal generated by the photoelectric conversion element333to the corresponding address event detector400R,400Gr,400Gb, or400B according to the control signal OFG. Here, the electric signal supplied to each of the address event detectors400R,400Gr,400Gb, and400B is a photoelectric current resulting from an electric charge generated in the photoelectric conversion element333of the corresponding light receiving portion330R,330Gr,330Gb, or330B.

The floating diffusion layer324accumulates an electric charge transferred as a photoelectric current from the photoelectric conversion element333via the transfer transistor331, and generates a voltage corresponding to the accumulated electric charge amount. The reset transistor321discharges (initializes) the electric charge accumulated in the floating diffusion layer324according to a reset signal from the driving circuit211. The amplification transistor322amplifies the voltage of the floating diffusion layer324. The selection transistor323outputs a signal of the voltage amplified by the amplification transistor322as the pixel signal SIG to the column ADC220via the vertical signal line VSL according to a selection signal SEL from the driving circuit211.

In response to instruction from the controller130to start detection of an address event, the driving circuit211drives the OFG transistors332of all the light receiving portions330R,330Gr,330Gb, and330B in the pixel array portion300by the control signal OFG to supply a photoelectric current. In this way, the photoelectric current is supplied to each of the address event detectors400R,400Gr,400Gb, and400B from the corresponding light receiving portion330R,330Gr,330Gb, or330B.

Outputs of a plurality of address event detectors400R,400Gr,400Gb, and400B associated with one pixel block310are integrated by the integration unit150which is a node that joins output lines of the respective address event detectors400R,400Gr,400Gb, and400B. Therefore, when any one of the address event detectors400R,400Gr,400Gb, and400B associated with a certain pixel block310detects firing of an address event, a request of the pixel block310is input to the arbiter213.

As described above, when a request in units of pixel blocks is input, the arbiter213arbitrates a request from each pixel block310, and transmits a predetermined response to a pixel block310issuing the request on the basis of an arbitration result. The pixel block310receiving this response supplies a detection signal (address event detection signal) indicating presence or absence of firing of an address event to the driving circuit211and the signal processing unit212.

The driving circuit211turns OFF OFG transistors332in all light receiving portions330R,330Gr,330Gb, and330B belonging to the pixel block310which is a supply source of the address event detection signal. In this way, supply of the photoelectric current to the corresponding address event detector400R,400Gr,400Gb, or400B from each of the light receiving portions330R,330Gr,330Gb, and330B in the pixel block310is suspended.

Subsequently, the driving circuit211drives the transfer transistors331in all the light receiving portions330R,330Gr,330Gb, and330B belonging to the pixel block310in order by the transfer signal TRG. In this way, an electric charge accumulated in the photoelectric conversion element333are transferred in order from all the light receiving portions330R,330Gr,330Gb, and330B of the pixel block310to the floating diffusion layer324of the pixel signal generator320. Then, pixel signals SIG of the plurality of respective unit pixels in the pixel block310are output in order from the pixel signal generator320.

As described above, the solid-state image pickup device200outputs pixel signals SIG from the light receiving portions330R,330Gr,330Gb, and330B included in the pixel block310from which firing of the address event is detected to the column ADC220. In this way, it is possible to reduce power consumption of the solid-state image pickup device200and the processing amount of image processing when compared to a case where pixel signals SIG are read from all unit pixels irrespective of presence or absence of firing of an address event.

2.7 Configuration Example of Address Event Detector

FIG. 12is a block diagram illustrating a schematic configuration example of the address event detector according to the first embodiment. As illustrated inFIG. 12, the address event detector400includes a current-voltage conversion unit410, a buffer420, a subtractor430, a quantizer440, and a transfer unit450. Note that in description below, in a case where the light receiving portions330R,330Gr,330Gb, and330B are not distinguished, reference numerals thereof are set to330. In a similar manner, in description below, in a case where the address event detectors400R,400Gr,400Gb, and400B are not distinguished, reference numerals thereof are set to400.

The current-voltage conversion unit410converts the photoelectric current from the light receiving portion330into a logarithmic voltage signal, and supplies the voltage signal generated in this way to the buffer420.

The buffer420corrects the voltage signal from the current-voltage conversion unit410, and outputs the voltage signal after correction to the subtractor430.

The subtractor430decreases a voltage level of the voltage signal from the buffer420according to the row driving signal from the driving circuit211and supplies the voltage signal after decrease to the quantizer440.

The quantizer440quantizes the voltage signal from the subtractor430into a digital signal and outputs the digital signal generated in this way to the transfer unit450as a detection signal.

The transfer unit450transfers the detection signal from the quantizer440to the signal processing unit212, etc. For example, when firing of the address event is detected, the transfer unit450supplies a request to the arbiter213for requesting transmission of an address event detection signal from the transfer unit450to the driving circuit211and the signal processing unit212. Then, upon receiving a response to the request from the arbiter213, the transfer unit450supplies the detection signal to the driving circuit211and the signal processing unit212.

2.8 Configuration Example of Current-Voltage Conversion Unit

FIG. 13is a circuit diagram illustrating a schematic configuration example of the current-voltage conversion unit according to the first embodiment. As illustrated inFIG. 13, the current-voltage conversion unit410includes N-type transistors411and413and a P-type transistor412. The N-type transistors411and413and the P-type transistor412may be, for example, MOS transistors.

A source of the N-type transistor411is connected to the light receiving portion330, and a drain thereof is connected to a power supply terminal. The P-type transistor412and the N-type transistor413are connected in series between the power supply terminal and an earth terminal. In addition, a connection node between the P-type transistor412and the N-type transistor413is connected to a gate of the N-type transistor411and an input terminal of the buffer420. In addition, a predetermined bias voltage Vbias is applied to a gate of the P-type transistor412.

The drains of the N-type transistors411and413are connected to the power supply side, thereby forming a source follower circuit. By configuring such a loop-like source follower circuit, the photoelectric current from the light receiving portion330is converted into a voltage signal having a logarithmic value corresponding to an electric charge amount thereof. In addition, the P-type transistor412supplies a constant current to the N-type transistor413.

2.9 Configuration Example of Subtractor and Quantizer

FIG. 14is a circuit diagram illustrating a schematic configuration example of the subtractor and the quantizer according to the first embodiment. The subtractor430includes capacitors431and433, an inverter432, and a switch434. In addition, the quantizer440includes a comparator441.

One end of the capacitor431is connected to an output terminal of the buffer420, and the other end thereof is connected to an input terminal of the inverter432. The capacitor433is connected in parallel with the inverter432. The switch434opens and closes a path connecting both ends of the capacitor433according to the row driving signal.

The inverter432inverts a voltage signal input via the capacitor431. The inverter432outputs the inverted signal to a non-inverting input terminal (+) of the comparator441.

When the switch434is turned ON, a voltage signal Vinit is input to the buffer420side of the capacitor431. In addition, the opposite side corresponds to a virtual earth terminal. For the sake of convenience, a potential of this virtual earth terminal is set to zero. In this instance, when the capacitance of the capacitor431is set to C1, the potential Qinit accumulated in the capacitor431is expressed by Equation (1) below. Meanwhile, since both ends of the capacitor433are short-circuited, an accumulated charge thereof becomes zero.
Qinit=C1×Vinit  (1)

Subsequently, considering a case where the switch434is turned OFF and the voltage on the buffer420side of the capacitor431is changed to Vafter, an electric charge Qafter accumulated in the capacitor431is expressed by the following Equation (2).
Qafter=C1×Vafter  (2)

Meanwhile, when an output voltage is set to Vout, an electric charge Q2accumulated in the capacitor433is expressed by the following Equation (3).
Q2=−C2×Vout  (3)

In this instance, since the total electric charge amount of the capacitors431and433does not change, the following Equation (4) is satisfied.
Qinit=Qafter+Q2  (4)

When Equation (4) is transformed by substituting Equations (1) to (3) into Equation (4), the following Equation (5) is obtained.
Vout=−(C1/C2)×(Vafter−Vinit)  (5)

Equation (5) represents a subtraction operation for voltage signals, and the gain of a subtraction result is C1/C2. Normally, since it is desirable to maximize the gain, it is preferable to design C1large and C2small. Meanwhile, when C2is excessively small, kTC noise increases, and a noise characteristic may deteriorate. Therefore, a capacity reduction of C2is limited to a range in which noise can be tolerated. In addition, since the address event detector400including the subtractor430is mounted for each pixel block, the capacitances C1and C2have restrictions on the area. Considering these facts, the values of the capacitances C1and C2are determined.

The comparator441compares the voltage signal from the subtractor430with a predetermined threshold voltage Vth applied to an inverting input terminal (−). The comparator441outputs a signal indicating a comparison result to the transfer unit450as a detection signal.

In addition, when the conversion gain of the current-voltage conversion unit410is set to CGlogand the gain of the buffer420is set to “1”, the gain A of the entire address event detector400is expressed by the following Expression (6).

In Equation (6), iphoto_n is a photoelectric current of an nth unit pixel. For example, a unit thereof is ampere (A). N is the number of unit pixels in the pixel block310.

2.10 Configuration Example of Column ADC

FIG. 15is a block diagram illustrating a schematic configuration example of the column ADC according to the first embodiment. The column ADC220includes a plurality of ADCs230provided for each column of the pixel block310.

Each ADC230converts the analog pixel signal SIG supplied via the vertical signal line VSL into a digital signal. The pixel signal SIG is converted into a digital signal having a larger number of bits than that of the detection signal. For example, when the detection signal is set to 2 bits, the pixel signal SIG is converted into a digital signal of 3 bits or more (16 bits, etc.). The ADC230supplies the generated digital signal to the signal processing unit212.

2.11 Operation Example of Solid-State Image Pickup Device

Next, an operation of the solid-state image pickup device200according to the present embodiment will be described in detail with reference to drawings.

2.11.1 Timing Chart

First, an example of an operation of the solid-state image pickup device200will be described with reference to a timing chart.FIG. 16is a timing chart illustrating the example of the operation of the solid-state image pickup device according to the first embodiment.

As illustrated inFIG. 16, when the controller130instructs that detection of an address event be started at a timing T0, the driving circuit211raises control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B applied to gates of OFG transistors332of all the light receiving portions330in the pixel array portion300to high levels. In this way, the OFG transistors332of all the light receiving portions330R,330Gr,330Gb, and330B are turned ON, and a photoelectric current based on an electric charge generated in the photoelectric conversion element333of each of the light receiving portions330R,330Gr,330Gb, and330B is supplied from each of the light receiving portions330R,330Gr,330Gb, and330B to each of the address event detectors400R,400Gr,400Gb, and400B.

In addition, during a period in which the control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B are at high levels, the transfer signals TRG-R, TRG-Gr, TRG-Gb, and TRG-B applied to the gates of the transfer transistors331in the respective light receiving portions330R,330Gr,330Gb, and330B are maintained at low level. For this reason, during this period, the transfer transistors331of all the light receiving portions330are in the OFF state.

Subsequently, it is presumed that one or more address event detectors400in each pixel block310detect firing of an address event during the period in which the control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B are at high levels. In this case, the address event detector400detecting firing of the address event transmits a request to the arbiter213. However, as described above, outputs of all the address event detectors400belonging to each pixel block310are integrated by the integration unit150and input to the arbiter213as a request in units of pixel blocks. For this reason, a response to the request is returned from the arbiter213to all the address event detectors400R,400Gr,400Gb, and400B belonging to the pixel block310including the address event detector400issuing the request (hereinafter referred to as a pixel block310to be read).

For example, the address event detectors400R,400Gr,400Gb, and400B receiving the response raise the detection signal input to the driving circuit211and the signal processing unit212to a high level during a period from a timing T1to a timing T2. Note that in this description, it is presumed that the detection signal is a 1-bit signal indicating a detection result of an ON event.

The driving circuit211to which the detection signal at the high level is input from the address event detectors400R,400Gr,400Gb, and400B at the timing T1lowers all the control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B to low levels at the subsequent timing T2. In this way, supply of the photoelectric currents from all the light receiving portions330of the pixel array portion300to the address event detector400is suspended.

In addition, the driving circuit211raises the selection signal SEL applied to the gate of the selection transistor323in the pixel signal generator320of the pixel block310to be read to a high level at the timing T2, and raises the reset signal RST applied to the gate of the reset transistor321of the same pixel signal generator320to a high level for a certain pulse period, thereby discharging (initializing) the electric charge accumulated in the floating diffusion layer324of the pixel signal generator320. In this way, a voltage appearing on the vertical signal line VSL in a state in which the floating diffusion layer324is initialized is read by the ADC230connected to the vertical signal line VSL in the column ADC220as a pixel signal at a reset level (hereinafter simply referred to as a reset level) and converted into a digital value.

Subsequently, at the timing T3after reading the reset level, for example, the driving circuit211applies a transfer signal TRG-R of a certain pulse period to the gate of the transfer transistor331of the light receiving portion330R in the pixel block310to be read. In this way, an electric charge generated in the photoelectric conversion element333of the light receiving portion330R is transferred to the floating diffusion layer324in the pixel signal generator320, and a voltage corresponding to the electric charge accumulated in the floating diffusion layer324appears on the vertical signal line VSL. In this way, the voltage appearing on the vertical signal line VSL is read by the ADC230connected to the vertical signal line VSL in the column ADC220as a pixel signal at a signal level of the light receiving portion330R (hereinafter simply referred to as a signal level) and converted into a digital value.

The signal processing unit212executes a CDS process of obtaining a difference between the reset level and the signal level read in this manner as a net pixel signal corresponding to the amount of light received by the photoelectric conversion element333.

Subsequently, at a timing T4after reading the signal level of the light receiving portion330R, for example, the driving circuit211applies a transfer signal TRG-Gr of a certain pulse period to the gate of the transfer transistor331of the light receiving portion330Gr in the pixel block310to be read in a same manner. In this way, an electric charge generated in the photoelectric conversion element333of the light receiving portion330Gr is transferred to the floating diffusion layer324in the pixel signal generator320, and a voltage corresponding to the electric charge accumulated in the floating diffusion layer324appears on the vertical signal line VSL. Then, the voltage appearing on the vertical signal line VSL is read by the ADC230of the column ADC220as a signal level of the light receiving portion330Gr and converted into a digital value.

Thereafter, similarly, signal levels of the light receiving portions330Gb and330B in the pixel block310to be read are read by the ADC230of the column ADC220and converted into digital values (timings T5and T6).

Thereafter, when reading of the signal levels from all the light receiving portions330in the pixel block310to be read is completed, the driving circuit211raises the control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B applied to gates of the OFG transistors332of all the light receiving portions330in the pixel array portion300to high levels, thereby supplying a photoelectric current based on the electric charge generated in the photoelectric conversion element333of each of the light receiving portions330R,330Gr,330Gb, and330B from each of the light receiving portions330R,330Gr,330Gb, and330B to each of the address event detectors400R,400Gr,400Gb, and400B.

Next, an example of an operation of the solid-state image pickup device200will be described with reference to a flowchart.FIG. 17is the flowchart illustrating the example of the operation of the solid-state image pickup device according to the first embodiment. For example, this operation is started when a predetermined application for detecting an address event is executed.

As illustrated inFIG. 17, in this operation, first, each of the pixel blocks310in the pixel array portion300detects presence or absence of firing of the address event (step S901). Then, the driving circuit211determines whether or not firing of the address event has been detected in any one of the pixel blocks310(step S902).

In a case where firing of the address event has not been detected (NO of step S902), this operation proceeds to step S904. On the other hand, in a case where firing of the address event has been detected (YES of step S902), the driving circuit211successively executes reading of pixel signals SIG on unit pixels belonging to a pixel block310from which firing of the address event has been detected, thereby successively reading the pixel signals SIG from the respective unit pixels belonging to the pixel block310to be read (step S903), and the operation proceeds to step S904.

In step S904, it is determined whether or not to end this operation. In the case of not ending this operation (NO of step S904), this operation returns to step S901, and subsequent operations are repeated. On the other hand, in the case of ending this operation (YES of step S904), this operation is ended.

As described above, in the first embodiment, a set (pixel block310) of a plurality of (N) unit pixels receiving a wavelength component used to reconstruct a color is set to a unit (pixel block unit) for detecting presence or absence of firing of an address event. Further, in a case where firing of the address event is detected in units of pixel blocks, pixel signals SIG are read in units of pixel blocks. In this way, when the address events fires in a unit pixel of a certain wavelength component, pixel signals SIG of all wavelength components used to reconstruct a color are synchronously read, and thus it is possible to reconstruct a correct color. As a result, it is possible to realize an event-driven type solid-state image pickup device and image pickup device capable of acquiring a color image in which a color is correctly reconstructed.

3. Second Embodiment

Next, a solid-state image pickup device and an image pickup device according to a second embodiment of the present disclosure will be described in detail with reference to drawings. Note that in description below, a similar configuration, operation, and effect to those of the above-described embodiment will be cited, thereby omitting a repeated description thereof.

In the first embodiment described above, individual address event detectors400are provided for individual light receiving portions330, and outputs of address event detectors400belonging to the same pixel block310are integrated by the integration unit150, so that a request in units of pixel blocks is input to the arbiter213. On the other hand, in the second embodiment, a case where a common address event detector400is provided for all light receiving portions330belonging to the same pixel block will be described by giving an example.

In the second embodiment, for example, a configuration example of the image pickup device, a configuration example of the solid-state image pickup device, a stacked configuration example of the solid-state image pickup device, a functional configuration example of the solid-state image pickup device, a configuration example of a pixel array portion, and an example of a pixel block may be similar to those described in the first embodiment with reference toFIG. 1toFIG. 8, and thus a detailed description is omitted here. However, in the present embodiment, for convenience of description, a reference numeral of the pixel block is set to510.

3.1 Detection of Firing of Address Event

In the present embodiment, as described above, a common address event detector400is provided for all light receiving portions330belonging to the same pixel block510. Therefore, in the present embodiment, firing of an address event is detected for each pixel block510, and pixel signals SIG are read from all unit pixels belonging to a pixel block510from which firing of the address event is detected. Note that in description below, for the sake of simplicity, an example is given for a case where the Bayer array is adopted as a color filter array and each pixel block510(corresponding to the pixel block310A) includes a total of four light receiving portions330R,330Gr,330Gb, and330B of 2×2 pixels included in a unit pattern thereof.

FIG. 18andFIG. 19are schematic diagrams illustrating an example of a configuration for detecting an address event according to the present embodiment. As illustrated inFIG. 18, for example, each of a plurality of light receiving portions330R,330Gr,330Gb, and330B included in the pixel block510has a similar configuration to a configuration described with reference toFIG. 9in the first embodiment. Meanwhile, in the present embodiment, a common address event detector400is provided for the plurality of light receiving portions330R,330Gr,330Gb, and330B.

As illustrated inFIG. 18andFIG. 19, photoelectric currents output from the respective light receiving portions330R,330Gr,330Gb, and330B are integrated by an integration unit250and input to the common address event detector400. In a case where a sum of photoelectric currents input from light receiving portions330R,330Gr,330Gb, and330B belonging to the same pixel block510or a change amount of the sum exceeds a predetermined threshold value, the address event detector400outputs a request for requesting reading of a pixel signal SIG to an arbiter213. In this way, in the present embodiment, in a case where a sum of photoelectric currents input from the light receiving portions330R,330Gr,330Gb, and330B belonging to the pixel block510or a change amount of the sum exceeds a predetermined threshold value, a request for reading of pixel signals SIG from four respective unit pixels belonging to the pixel block510is input to the arbiter213.

3.2 Configuration Example of Pixel Block

Next, a configuration example of the pixel block will be described.FIG. 20is a circuit diagram illustrating a schematic configuration example of the pixel block according to the second embodiment. As illustrated inFIG. 20, in the pixel block510according to the present embodiment, the plurality of address event detectors400R,400Gr,400Gb, and400B provided for the respective light receiving portions on a one-to-one basis in a similar configuration to that of the pixel block310described with reference toFIG. 11in the first embodiment is replaced by one common address event detector400. In addition, outputs of the respective light receiving portions330R,330Gr,330Gb, and330B are integrated by the integration unit250and input to the address event detector400.

In the respective light receiving portions330R,330Gr,330Gb, and330B, OFG transistors332output electric signals generated by photoelectric conversion elements333according to control signals OFG. The electric signals (photoelectric currents) output from the light receiving portions330R,330Gr,330Gb, and330B are integrated by the integration unit250and supplied to the address event detector400.

When firing of an address event is detected on the basis of the integrated electric signal, the address event detector400outputs a request to the arbiter213. In this way, a request in units of pixel blocks is input to the arbiter213.

When a request in units of pixel blocks is input, the arbiter213arbitrates requests from respective pixel blocks510and transmits a predetermined response to a pixel block510issuing the request on the basis of an arbitration result. The pixel block510receiving this response supplies a detection signal (address event detection signal) indicating presence of absence of firing of the address event to a driving circuit211and a signal processing unit212.

The driving circuit211turns OFF the OFG transistors332in all the light receiving portions330R,330Gr,330Gb, and330B belonging to the pixel block510which is a supply source of the address event detection signal. In this way, supply of the photoelectric current from the light receiving portions330R,330Gr,330Gb, and330B in the pixel block510to the address event detector400is suspended.

Subsequently, the driving circuit211drives the transfer transistors331in all the light receiving portions330R,330Gr,330Gb, and330B belonging to the pixel block510in order by a transfer signal TRG. In this way, an electric charge accumulated in the photoelectric conversion element333are transferred in order from all the light receiving portions330R,330Gr,330Gb, and330B of the pixel block510to a floating diffusion layer324of a pixel signal generator320. Then, pixel signals SIG of the plurality of respective unit pixels in the pixel block510are output in order from the pixel signal generator320.

Since other configurations may be similar to those of the pixel block310described with reference toFIG. 11in the first embodiment, a detailed description thereof will be omitted here. In addition, in the present embodiment, for example, a configuration example of the address event detector, a configuration example of a current-voltage conversion unit, a configuration example of a subtractor and a quantizer, and a configuration example of a column ADC are similar to those described with reference toFIG. 12toFIG. 15in the first embodiment, and thus a detailed description thereof will be omitted here.

3.3 Operation Example of Solid-State Image Pickup Device

Next, a description will be given of an operation of a solid-state image pickup device200according to the present embodiment. For example, an operation example of the solid-state image pickup device200according to the present embodiment may be similar to the operation example described with reference toFIG. 16andFIG. 17in the first embodiment. However, in the present embodiment, during a period in which control signals OFG-R, OFG-Gr, OFG-Gb, and OFG-B are at high levels (see the timings T0to T2ofFIG. 16), the photoelectric currents output from the light receiving portions330R,330Gr,330Gb, and330B and integrated by the integration unit250are input to the address event detector400. Therefore, in the present embodiment, the address event detector400detects presence or absence of firing of the address event in units of pixel blocks on the basis of the integrated photoelectric current, and transmits a request to the arbiter213in a case where firing of the address event is detected. Then, upon receiving a predetermined response from the arbiter213, for example, the address event detector400raises a detection signal input to the driving circuit211and the signal processing unit212to a high level during a period from the timing T1to the timing T2.

Since other operations may be similar to the operations described with reference toFIG. 16andFIG. 17in the first embodiment, a detailed description thereof will be omitted here.

As described above, in the second embodiment, similarly to the first embodiment, a set (pixel block310) of a plurality (N) of unit pixels that receive wavelength components used to reconstruct a color is set as a unit (pixel block unit) for detecting presence or absence of firing of an address event, and pixel signals SIG are read in units of pixel blocks in a case where firing of the address event is detected in units of pixel blocks. In this way, when the address event fires in a unit pixel of a certain wavelength component, pixel signals SIG of all wavelength components used to reconstruct a color are synchronously read, and thus it is possible to reconstruct a correct color. As a result, it is possible to realize an event-driven type solid-state image pickup device and image pickup device capable of acquiring a color image in which a color is correctly reconstructed.

In addition, the second embodiment includes the address event detector400provided for the pixel block510on a one-to-one basis instead of the address event detector400provided for the light receiving portion330on a one-to-one basis. In this way, by adopting a configuration in which one address event detector400is shared by a plurality of light receiving portions330belonging to the same pixel block510, it is possible to reduce a circuit scale when compared to a case where an individual address event detector400is provided for the light receiving portion330.

Since other configurations, operations, and effects may be similar to those of the above embodiment, a detailed description thereof will be omitted.

Next, a solid-state image pickup device and an image pickup device according to a third embodiment of the present disclosure will be described in detail with reference to drawings. Note that in description below, a similar configuration, operation, and effect to those of the above-described embodiments will be cited, thereby omitting a repeated description thereof.

In the above-described embodiments, a case where each pixel block310/510includes a set of unit pixels receiving wavelength components used to reconstruct a color to reconstruct a correct color has been described by giving an example. Meanwhile, in the present embodiment, a description will be given of a case for reconstructing correct polarization information by giving an example.

Note that the polarization information is information related to polarization of incident light, and may correspond to, for example, information related to a polarization state of linear polarization, circular polarization, elliptic polarization, random polarization, etc., information related to a polarization direction in the case of linear polarization, information related to a major axis or a minor axis in the case of elliptic polarization, etc.

In the third embodiment, for example, a configuration example of the image pickup device, a configuration example of the solid-state image pickup device, a stacked configuration example of the solid-state image pickup device, a functional configuration example of the solid-state image pickup device, a configuration example of a pixel array portion, a configuration example of an address event detector, a configuration example of a current-voltage conversion unit, a configuration example of a subtractor and a quantizer, and a configuration example of a column ADC may be similar to those described in the first embodiment with reference toFIG. 1toFIG. 4andFIG. 12toFIG. 15, and thus a detailed description is omitted here.

In addition, in the third embodiment, for example, detection of firing of address event and a configuration example of a pixel block may be similar to those described in the first embodiment with reference toFIG. 9,FIG. 10, andFIG. 11or those described in the second embodiment with reference toFIG. 18,FIG. 19, andFIG. 20, and thus a detailed description is omitted here.

Further, for example, an operation example of the solid-state image pickup device200according to the third embodiment may be similar to the operation descried in the first or second embodiment with reference toFIG. 16andFIG. 17, and thus a detailed description is omitted here.

However, in the present embodiment, for convenience of description, a reference numeral of the pixel block is set to610. In addition, in the present embodiment, the number of light receiving portions330belonging to one pixel block610is set to three for a reason described later.

4.1 Example of Pixel Block

For example, the pixel block610according to the present embodiment includes a combination of unit pixels that receive polarization components used to reconstruct polarization information. For example, the polarization information can be obtained by fitting a sinusoid. For this reason, to reconstruct the polarization information, it is necessary to observe incident light using at least three polarizers having different rotation angles about an optical axis of a polarization axis.

Therefore, in the present embodiment, as in the pixel block610illustrated inFIG. 21, for example, three types of polarizers614H,614V, and614S having different rotation angles about the optical axis of the polarization axis are used, and the three types of polarizers614H,614V, and614S are disposed in predetermined repetitive patterns with respect to a plurality of light receiving portions330arrayed in a 2D lattice pattern. Further, in the present embodiment, a set of three unit pixels including the repetitive patterns, that is, the three types of polarizers614H,614V, and614S, respectively, is grouped as one pixel block610. Note that for simplicity of description, inFIG. 21, the pixel signal generator320and the address event detector400are omitted.

In a configuration illustrated inFIG. 21, for example, the polarizer614H is a polarizer provided so that a polarization axis is parallel to a row direction of the light receiving portion330. Therefore, a light receiving portion630H, which is formed by combining the polarizer614H and the light receiving portion330, receives a polarization component parallel to the row direction of the light receiving portion330and generates an electric charge corresponding to the received light amount. In addition, for example, the polarizer614V is a polarizer provided so that a polarization axis is parallel to a column direction of the light receiving portion330. Therefore, a light receiving portion630V, which is formed by combining the polarizer614V and the light receiving portion330, receives a polarization component parallel to the row direction of the light receiving portion330and generates an electric charge corresponding to the received light amount. Further, for example, the polarizer614S is a polarizer provided so that a polarization axis is inclined at a predetermined inclination with respect to the row direction and the column direction of the light receiving portion330. Therefore, a light receiving portion630S, which is formed by combining the polarizer614S and the light receiving portion330, receives a polarization component inclination at the predetermined inclination with respect to the row direction and the column direction of the light receiving portion330and generates an electric charge corresponding to the received light amount.

Note thatFIG. 21illustrates a case where each pixel block610is grouped on the basis of the three polarizers614H,614V, and614S arrayed in order in the row direction. However, the present disclosure is not limited thereto. For example, each pixel block610may be grouped on the basis of a pattern in which two of the three polarizers614H,614V, and614S are disposed in the row direction and the remaining one is disposed in the column direction with respect to one of the other two.

As described above, in the third embodiment, instead of the wavelength selection elements (color filters314R,314Gr,314Gb,314B, etc.) used in the first and second embodiments, at least three polarizers614H,614V, and614S having different rotation angles about the optical axis of the polarization axis are provided for the light receiving portion330, and a set of unit pixels, each of which includes at least one of the polarizers614H,614V, and614S, is grouped as one pixel block610. In this way, similarly to the above-described embodiments, in a case where firing of an address event is detected in units of pixel blocks, pixel signals SIG are read in units of pixel blocks. Thus, when an address event fires in a unit pixel of a certain polarization component, pixel signals SIG of at least three polarization components used to reconstruct polarization information are synchronously read. In this way, it is possible to reconstruct correct polarization information on the basis of the pixel signals SIG read in units of pixel blocks. As a result, it is possible to realize an event-driven type solid-state image pickup device and image pickup device capable of acquiring image data including information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc.

Since other configurations, operations, and effects may be similar to those of the above embodiments, a detailed description thereof will be omitted.

The third embodiment described above illustrates a case where three types of polarizers614H,614V, and614S having different rotation angles about the optical axis of the polarization axis are disposed in predetermined repetitive patterns with respect to the plurality of light receiving portions330arrayed in the 2D lattice pattern, and a set of three unit pixels including the repetitive patterns, that is, the three types of polarizers614H,614V, and614S, respectively, is grouped as one pixel block610. On the other hand, in a fourth embodiment, four types of polarizers are disposed in predetermined repetitive patterns with respect to a plurality of light receiving portions330arrayed in a 2D lattice pattern, and a set of four unit pixels including the repetitive patterns, that is, the four types of polarizers, respectively, is grouped as one pixel block.

In the fourth embodiment, for example, a configuration example of the image pickup device, a configuration example of the solid-state image pickup device, a stacked configuration example of the solid-state image pickup device, a functional configuration example of the solid-state image pickup device, a configuration example of a pixel array portion, detection of firing of an address event, a configuration example of a pixel block, a configuration example of an address event detector, a configuration example of a current-voltage conversion unit, a configuration example of a subtractor and a quantizer, a configuration example of a column ADC, and an operation example of the solid-state image pickup device200may be similar to those described in the third embodiment, and thus a detailed description is omitted here. However, in the present embodiment, for convenience of description, a reference numeral of the pixel block is set to710.

5.1 Example of Pixel Block

FIG. 22is a schematic diagram illustrating an example of a pixel block according to the fourth embodiment. Note that for simplicity of description, inFIG. 22, the pixel signal generator320and the address event detector400are omitted.

As illustrated inFIG. 22, the pixel block710according to the present embodiment has a configuration in which polarizers614H1and614H2provided so that polarization axes thereof are parallel to a row direction of a light receiving portion330and polarizers614V1and614V2provided so that polarization axes thereof are parallel to a column direction of the light receiving portion330are disposed in a predetermined array.

A light receiving portion630H1formed by combining the polarizer614H1and the light receiving portion330receives a polarization component parallel to the row direction of a light receiving portion330and generates an electric charge corresponding to the received light amount. A light receiving portion630H2formed by combining the polarizer614H2and the light receiving portion330receives a polarization component parallel to the row direction of the light receiving portion330and generates an electric charge corresponding to the received light amount. A light receiving portion630V1formed by combining the polarizer614V1and the light receiving portion330receives a polarization component parallel to the row direction of the light receiving portion330and generates an electric charge corresponding to the received light amount. A light receiving portion630V2formed by combining the polarizer614V2and the light receiving portion330receives a polarization component parallel to the row direction of the light receiving portion330and generates an electric charge corresponding to the received light amount.

Note that the polarization axis of the polarizer614H1and the polarization axis of the polarizer614H2may be parallel to each other or inclined at a predetermined angle. Similarly, the polarization axis of the polarizer614V1and the polarization axis of the polarizer614V2may be parallel to each other or inclined at a predetermined angle. However, it is presumed that the polarization axis of the polarizer614V1and the polarization axis of the polarizer614V2are inclined at a predetermined angle in a case where the polarization axis of the polarizer614H1and the polarization axis of the polarizer614H2are parallel to each other, and the polarization axis of the polarizer614H1and the polarization axis of the polarizer614H2are inclined at a predetermined angle in a case where the polarization axis of the polarizer614V1and the polarization axis of the polarizer614V2are parallel to each other.

As described above, even in a case where the number of unit pixels used to reconstruct polarization information is set to four, similarly to the third embodiment, when an address event fires in a unit pixel of a certain polarization component, pixel signals SIG of at least three polarization components used to reconstruct polarization information are synchronously read. Thus, it is possible to reconstruct correct polarization information on the basis of the pixel signals SIG read in units of pixel blocks. As a result, it is possible to realize an event-driven type solid-state image pickup device and image pickup device capable of acquiring image data including information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc.

Since other configurations, operations, and effects may be similar to those of the above embodiments, a detailed description thereof will be omitted.

The wavelength selection element illustrated in the first or second embodiment may be combined with the polarizer illustrated in the third or fourth embodiment. That is, it is possible to adopt a configuration in which a polarization component used to reconstruct polarization information is acquired for each wavelength component used to reconstruct a color. In this way, it is possible to acquire a color image which includes information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc. and in which a color is correctly reconstructed.

In the fifth embodiment, for example, a configuration example of the image pickup device, a configuration example of the solid-state image pickup device, a stacked configuration example of the solid-state image pickup device, a functional configuration example of the solid-state image pickup device, a configuration example of a pixel array portion, detection of firing of an address event, a configuration example of a pixel block, a configuration example of an address event detector, a configuration example of a current-voltage conversion unit, a configuration example of a subtractor and a quantizer, a configuration example of a column ADC, and an operation example of the solid-state image pickup device200may be similar to those described in the third embodiment, and thus a detailed description is omitted here. However, in the present embodiment, for convenience of description, a reference numeral of the pixel block is set to810.

In addition, in description below, a case where the Bayer array is adopted as a color filter array and the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment are combined with this Bayer array is illustrated. However, the present disclosure is not limited thereto, and the polarizers614H,614V, and614S illustrated in the third embodiment, the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment, etc. may be combined with another color filter array such as the X-Trans (registered trademark) type array or the Quad Bayer array.

6.1 Example of Pixel Block

FIG. 23is a schematic diagram illustrating an example of the pixel block according to the fifth embodiment. Note that for simplicity of description, inFIG. 23, the light receiving portion330, the pixel signal generator320, and the address event detector400are omitted.

As illustrated inFIG. 23, the pixel block810according to the present embodiment has a configuration in which each of the polarizers614H1,614V1,614V2, and614H2is combined with a unit pattern820A of a Bayer array including 2×2 pixels of a color filter314R of red (R) color, a color filter314Gr of green (Gr) color, a color filter314Gb of green (Gb) color, and a color filter314B of blue (B) color.

More specifically, for example, inFIG. 23, in an upper left pixel group830H1, a unit pattern820A is combined with a polarizer group840H1. The polarizer group840H1includes a total of four polarizers614H1corresponding to the respective color filters314R,314Gr,314Gb, and314B included in the unit pattern820A on a one-to-one basis.

Similarly, in an upper right pixel group830V1, a polarizer group840V1including a total of four polarizers614V1corresponding to the respective color filters314R,314Gr,314Gb, and314B on a one-to-one basis is combined with a unit pattern820A. In addition, in a lower left pixel group830V2, a polarizer group840V2including a total of four polarizers614V2corresponding to the respective color filters314R,314Gr,314Gb, and314B on a one-to-one basis is combined with a unit pattern820A. Further, in a lower right pixel group830H2, a polarizer group840H2including a total of four polarizers614H2corresponding to the respective color filters314R,314Gr,314Gb, and314B on a one-to-one basis is combined with a unit pattern820A.

As described above, the pixel block810according to the present embodiment has unit pixels, the number (sixteen) of which is obtained by multiplying the number (four) of the color filters314R,314Gr,314Gb, and314B included in the unit pattern820A by the number (four) of types of the polarizers614H1,614V1,614V2, and614H2combined therewith.

FIG. 24is a schematic diagram illustrating an example of a pixel block according to Modification 1 of the fifth embodiment.FIG. 23illustrates a case where the polarizers614H1,614V1,614V2, and614H2are combined with the color filters314R,314Gr,314Gb, and314B included in the unit pattern820A, respectively, on a one-to-one basis. However, the present disclosure is not limited to such a configuration. For example, as in a pixel block910illustrated inFIG. 24, each of the polarizer groups840H1,840V1,840V2, and840H2combined with the four unit patterns820A, respectively, may be configured by one polarizer914H1,914V1,914V2, or914H2.

In addition,FIG. 25is a schematic diagram illustrating an example of a pixel block according to Modification 2 of the fifth embodiment. Modification 2 illustrates a pixel block1210in a case where the X-Trans (registered trademark) type array is adopted as a color filter array. Note that in the present description, for clarity, a polarizer combined with the X-Trans (registered trademark) type array is set to the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment. In addition, inFIG. 25, for simplicity of description, the light receiving portion330, the pixel signal generator320, and the address event detector400are omitted.

As illustrated inFIG. 25, for example, the pixel block1210based on the X-Trans (registered trademark) type array includes a pixel group1230H1in which a polarizer group1240H1having nine polarizers614H1is combed with a unit pattern1220A of the X-Trans (registered trademark) type array, a pixel group1230V1in which a polarizer group1240V1having nine polarizers614V1is combed with a unit pattern1220A, a pixel group1230V2in which a polarizer group1240V2having nine polarizers614V2is combed with a unit pattern1220A, and a pixel group1230H2in which a polarizer group1240H2having nine polarizers614H2is combed with a unit pattern1220A.

As described above, by combining the wavelength selection element illustrated in the first or second embodiment with the polarizer illustrated in the third or fourth embodiment, it is possible to realize an event-driven type solid-state image pickup device or image pickup device capable of acquiring a color image which includes information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc. and in which a color is correctly reconstructed.

Since other configurations, operations, and effects may be similar to those of the above embodiments, a detailed description thereof will be omitted.

In the above-described fifth embodiment, a case where a polarizer is combined with a color filter without changing an array thereof is illustrated. On the other hand, in a sixth embodiment, for example, the case of combining a color filter with a polarizer without changing a repetitive pattern thereof will be described by giving an example.

Note that in description below, a case where the Bayer array is adopted as a color filter array and the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment are combined with this Bayer array is illustrated. However, the present disclosure is not limited thereto, and the polarizers614H,614V, and614S illustrated in the third embodiment, the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment, etc. may be combined with another color filter array such as the X-Trans (registered trademark) type array or the Quad Bayer array.

7.1 Example of Pixel Block

FIG. 26is a schematic diagram illustrating an example of the pixel block according to the sixth embodiment. Note that for simplicity of description, inFIG. 26, the light receiving portion330, the pixel signal generator320, and the address event detector400are omitted.

As illustrated inFIG. 26, a pixel block1010according to the present embodiment has a configuration in which each of the color filters314R,314Gr,314Gb, and314B included in the unit pattern of the Bayer array is divided into four parts. Note that the configuration in which each of the color filters314R,314Gr,314Gb, and314B included in the unit pattern of the Bayer array is divided into four parts corresponds to, for example, a color filter array similar to the Quad Bayer array illustrated inFIG. 7.

InFIG. 26, for example, in an upper left pixel group1030R corresponding to color filters of red (R) color in a unit pattern of the Bayer array, a polarizer group1040A including four polarizers614H1,614V1,614V2, and614H2corresponding to color filters314R, respectively, on a one-to-one basis is combined with a color filter group1020R including a total of four color filters314R of red (R) color of 2×2 pixels. For example, an array (repetitive pattern) of the polarizers614H1,614V1,614V2, and614H2in the polarizer group1040A may be similar to that of the above-described fourth embodiment.

Similarly, in an upper right pixel group1030Gr corresponding to color filters of green (Gr) color in a unit pattern of the Bayer array, a polarizer group1040A is combined with a color filter group1020Gr including a total of four color filters314Gr of green (Gr) color of 2×2 pixels. In addition, in a lower left pixel group1030Gb corresponding to color filters of green (Gb) color in a unit pattern of the Bayer array, a polarizer group1040A is combined with a color filter group1020Gb including a total of four color filters314Gb of green (Gb) color of 2×2 pixels. Further, in a lower right pixel group1030B corresponding to color filters of blue (B) color in a unit pattern of the Bayer array, a polarizer group1040A is combined with a color filter group1020B including a total of four color filters314B of blue (B) color of 2×2 pixels.

FIG. 27is a schematic diagram illustrating an example of a pixel block according to Modification 1 of the sixth embodiment.FIG. 26illustrates a case where each of color filters arrayed in a predetermined color filter array (for example, the Bayer array) is divided into parts, the number of which corresponds to the number of polarizers to be combined therewith. However, the present disclosure is not limited to such a configuration. For example, as in a pixel block1110illustrated inFIG. 27, each of the color filters314R,314Gr,314Gb, and314B may not be divided and a size thereof may be changed to combine the polarizer group1040A with each of the color filters314R,314Gr,314Gb, and314B.

In addition,FIG. 28is a schematic diagram illustrating an example of a pixel block according to Modification 2 of the sixth embodiment. Modification 2 illustrates a pixel block1310of a case where the X-Trans (registered trademark) type array is adopted as a color filter array. Note that in the present description, for clarity, a polarizer combined with the X-Trans (registered trademark) type array is set to the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment. In addition, inFIG. 28, for simplicity of description, the light receiving portion330, the pixel signal generator320, and the address event detector400are omitted.

As illustrated inFIG. 28, for example, the pixel block1310based on the X-Trans (registered trademark) type array has a configuration in which each of the color filters314R,314G, and314B in a unit pattern1220A of the X-Trans (registered trademark) type array is divided into parts, the number (four) of which corresponds to the number of polarizers614H1,614V1,614V2, and614H2to be combined therewith.

Therefore, inFIG. 28, for example, in each of upper left, upper right, middle, lower left, and lower right pixel groups1330G1,1330G2,1330G3,1330G4, and1330G5corresponding to color filters of green (G) color in a unit pattern of the X-Trans (registered trademark) type array, a polarizer group1040A including four polarizers614H1,614V1,614V2, and614H2corresponding to color filters314G, respectively, on a one-to-one basis is combined with a color filter group1320G including the color filters314G of 2×2 pixels.

Similarly, in each of upper middle and lower middle pixel groups1330B1and1330B2corresponding to color filters of blue (B) color in a unit pattern, a polarizer group1040A is combined with a color filter group1320B including a total of four color filters314B of blue (B) color of 2×2 pixels. In addition, in each of middle left and middle right pixel groups1330R1and1330R2corresponding to color filters of read (R) color in a unit pattern, a polarizer group1040A is combined with a color filter group1320R including a total of four color filters314R of read (R) color of 2×2 pixels.

As described above, even in a case where a color filter is combined with a polarizer without changing a repetitive pattern thereof, similarly to the fifth embodiment, it is possible to realize an event-driven type solid-state image pickup device or image pickup device capable of acquiring a color image which includes information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc. and in which a color is correctly reconstructed.

Since other configurations, operations, and effects may be similar to those of the above embodiments, a detailed description thereof will be omitted.

In addition, for example, the polarizer illustrated in the third or fourth embodiment may be combined with the pixel block310D having a structure in which the light receiving portions330G,330B, and330R are provided for one pixel area330G/B/R illustrated in the first embodiment with reference toFIG. 8.

FIG. 29is a schematic diagram illustrating an example of a pixel block according to a seventh embodiment. Note that for simplicity of description, inFIG. 29, the light receiving portion330, the pixel signal generator320, and the address event detector400are omitted.

As illustrated inFIG. 29, in a case where the light receiving portions330G,330B, and330R for receiving wavelength components used to reconstruct a color are concentrated in one pixel area330G/B/R, the number of light receiving portions330G/B/R grouped into a pixel block1410is determined by the number of polarizers included in a repetitive pattern. Therefore, for example, as illustrated inFIG. 29, in a case where the polarizers614H1,614V1,614V2, and614H2illustrated in the fourth embodiment are combined, the number of light receiving portions330G/B/R grouped into the pixel block1410is four.

As described above, even in a case where the light receiving portions330G,330B, and330R for receiving wavelength components used to reconstruct a color are integrated in one pixel area330G/B/R, for example, by combining with the polarizer illustrated in the third or fourth embodiment, it is possible to realize an event-driven type solid-state image pickup device or image pickup device capable of acquiring a color image which includes information as to whether or not incident light is natural light or reflected light reflected by an object, a water surface, etc., or about a polarization state of light from a light source, etc. and in which a color is correctly reconstructed.

Since other configurations, operations, and effects may be similar to those of the above embodiments, a detailed description thereof will be omitted.

Even though the embodiment of the present disclosure has been described above, the technical scope of the present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from a subject matter of the present disclosure. In addition, constituent elements according to different embodiments and modifications may be appropriately combined.

In addition, the effects of the respective embodiments described in this specification are merely examples and are not limited, and other effects may be provided.

Note that the present technology may adopt the following configurations.

A solid-state image pickup device including

a plurality of light receiving portions, each of which receives light of a specific wavelength to generate an electric charge corresponding to an amount of the received light,

a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions,

a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and

a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

The solid-state image pickup device according to item (1), in which the detector detects a current value of the photoelectric current or a change amount of the current value.

The solid-state image pickup device according to item (1) or (2),

in which the plurality of light receiving portions is grouped into a pixel block for every at least two light receiving portions,

the detector detects a photoelectric current based on the electric charge generated in the at least one of light receiving portions belonging to the pixel block for each pixel block, and

the driving circuit causes the generator to generate the voltage signals based on respective electric charges generated in the light receiving portions belonging to the pixel block for each pixel block on the basis of the detection result of the photoelectric current for each pixel block by the detector.

The solid-state image pickup device according to item (3), in which the light receiving portions belonging to each pixel block receive lights of specific wavelengths different from each other.

The solid-state image pickup device according to item (4), in which each pixel block includes a combination of light receiving portions receiving wavelength components used to reconstruct a color of incident light, respectively.

The solid-state image pickup device according to any one of items (3) to (5), in which each pixel block includes a first light receiving portion receiving a wavelength component of red, a second light receiving portion receiving a wavelength component of green, and a third light receiving portion receiving a wavelength component of blue.

The solid-state image pickup device according to any one of items (3) to (6),

in which the detector is provided for each of the plurality of light receiving portions, and

the solid-state image pickup device further includes

an integration unit that integrates the detection results output from a plurality of the detectors provided for the light receiving portions belonging to the pixel block for each pixel block.

The solid-state image pickup device according to any one of items (3) to (6),

in which the detector is provided for each pixel block,

the solid-state image pickup device further includes

an integration unit that integrates the photoelectric currents output from the respective light receiving portions belonging to each pixel block for each pixel block, and

the detector for each pixel block detects the photoelectric currents input through the integration unit.

The solid-state image pickup device according to any one of items (3) to (8), in which the plurality of light receiving portions is arrayed in a 2D lattice pattern according to a predetermined array.

The solid-state image pickup device according to item (9), in which the predetermined array corresponds to any one of a Bayer array, an X-Trans (registered trademark) type array, and a Quad Bayer array.

The solid-state image pickup device according to item (9) or (10),

in which the predetermined array has a configuration in which a basic pattern obtained by combining the light receiving portions for respective wavelength components used to reconstruct a color of incident light in a predetermined arrangement is repeatedly disposed, and

the plurality of light receiving portions is grouped into the pixel block for each basic pattern.

The solid-state image pickup device according to any one of items (1) to (11),

in which each of the plurality of light receiving portions includes

a photoelectric conversion element that receives light of the specific wavelength to generate the electric charge corresponding to the amount of the received light, and

a first transistor that supplies the electric charge generated in the photoelectric conversion element to the detector as the photoelectric current according to control from the driving circuit.

The solid-state image pickup device according to item (12),

in which each of the plurality of light receiving portions further includes a second transistor that transfers the electric charge generated in the photoelectric conversion element to the generator according to control from the driving circuit, and

the generator includes

a floating diffusion layer that accumulates the electric charge transferred from any one of the plurality of light receiving portions through the second transistor,

a third transistor that discharges the electric charge accumulated in the floating diffusion layer according to control from the driving circuit,

a fourth transistor that causes the voltage signal corresponding to an electric charge amount of the electric charge accumulated in the floating diffusion layer to appear on a predetermined signal line, and

a fifth transistor that switches connection between the fourth transistor and the predetermined signal line according to control from the driving circuit.

The solid-state image pickup device according to any one of items (3) to (11),

in which each of the plurality of light receiving portions further includes

a photoelectric conversion element that receives light of the specific wavelength to generate the electric charge corresponding to the amount of the received light,

a first transistor that supplies the electric charge generated in the photoelectric conversion element to the detector as the photoelectric current according to control from the driving circuit, and

a second transistor that transfers the electric charge generated in the photoelectric conversion element to the generator according to control from the driving circuit,

the generator includes

a floating diffusion layer that accumulates the electric charge transferred from any one of the plurality of light receiving portions through the second transistor,

a third transistor that discharges the electric charge accumulated in the floating diffusion layer according to control from the driving circuit,

a fourth transistor that causes the voltage signal corresponding to an electric charge amount of the electric charge accumulated in the floating diffusion layer to appear on a predetermined signal line, and

a fifth transistor that switches connection between the fourth transistor and the predetermined signal line according to control from the driving circuit,

the detector detects presence or absence of firing of an event on the basis of the photoelectric current, and

in a case where the detector detects firing of the event during a period in which the first transistor of each of the plurality of light receiving portions is controlled to be in an ON state, the driving circuit performs a control operation to turn OFF the first transistor of each of the light receiving portions belonging to a pixel block from which firing of the event is detected, performs a control operation to turn ON the fifth transistor, turns ON the third transistor for a certain period, and then performs a control operation to turn ON second transistors of the respective light receiving portions belonging to the pixel block for a certain period according to a predetermined order.

The solid-state image pickup device according to item (13) or (14), further including

a conversion unit that converts the voltage signal appearing on the predetermined signal line into a digital value corresponding to a voltage value.

The solid-state image pickup device according to any one of items (1) to (15),

in which each of the plurality of light receiving portions includes

a photoelectric conversion element that receives light of the specific wavelength to generate the electric charge corresponding to the amount of the received light, and

a wavelength selection element that limits a wavelength of the light incident on the photoelectric conversion element to the specific wavelength.

The solid-state image pickup device according to any one of items (1) to (16), further including a polarizer provided for each of the plurality of light receiving portions.

The solid-state image pickup device according to any one of items (3) to (11), further including

a polarizer provided for each of the plurality of light receiving portions,

in which polarizers provided for at least two light receiving portions belonging to each pixel block, respectively, have rotation angles about an optical axis of a polarization axis different from each other.

The solid-state image pickup device according to item (18), in which each pixel block includes light receiving portions, the number of which is obtained by multiplying the number of wavelength components used to reconstruct a color of incident light by the number of polarizers having the rotation angles about the optical axis of the polarization axis different from each other.

An image pickup device including

a plurality of light receiving portions, each of which receives light of a specific wavelength to generate an electric charge corresponding to an amount of the received light,

a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions,

a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and

a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

A solid-state image pickup device including

a plurality of light receiving portions, each of which receives light in a specific polarization direction to generate an electric charge corresponding to an amount of the received light,

a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions,

a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and

a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

The solid-state image pickup device according to item (21), in which the detector detects a current value of the photoelectric current or a change amount of the current value.

The solid-state image pickup device according to item (21) or (22),

in which the plurality of light receiving portions is grouped into a pixel block for every at least two light receiving portions,

the detector detects a photoelectric current based on an electric charge generated in at least one of light receiving portions belonging to the pixel block for each pixel block, and

the driving circuit causes the generator to generate the voltage signals based on respective electric charges generated in the light receiving portions belonging to the pixel block for each pixel block on the basis of the detection result of the photoelectric current for each pixel block by the detector.

The solid-state image pickup device according to item (23), in which the light receiving portions belonging to each pixel block receive lights in specific polarization directions different from each other.

The solid-state image pickup device according to item (24), in which each pixel block includes a combination of light receiving portions receiving the lights in the specific polarization directions used to reconstruct polarization information of incident light, respectively.

The solid-state image pickup device according to any one of items (23) to (25), in which each pixel block includes a first light receiving portion receiving light in a first polarization direction, a second light receiving portion receiving light in a second polarization direction, and a third light receiving portion receiving light in a third polarization direction.

The solid-state image pickup device according to any one of items (23) to (26),

in which the detector is provided for each of the plurality of light receiving portions, and

the solid-state image pickup device further includes

an integration unit that integrates the detection results output from a plurality of the detectors provided for the light receiving portions belonging to the pixel block for each pixel block.

The solid-state image pickup device according to any one of items (23) to (26),

in which the detector is provided for each pixel block,

the solid-state image pickup device further includes

an integration unit that integrates the photoelectric currents output from the respective light receiving portions belonging to each pixel block for each pixel block, and

the detector for each pixel block detects the photoelectric currents input through the integration unit.

The solid-state image pickup device according to any one of items (23) to (28), in which the plurality of light receiving portions is arrayed in a 2D lattice pattern according to a predetermined array.

The solid-state image pickup device according to item (29),

in which the predetermined array has a configuration in which a repetitive pattern formed by combining the light receiving portions for the respective polarization directions used to reconstruct polarization information of incident light in a predetermined arrangement is repeatedly disposed, and

the plurality of light receiving portions is grouped into the pixel block for each repetitive pattern.

The solid-state image pickup device according to any one of items (21) to (30),

in which each of the plurality of light receiving portions includes

a photoelectric conversion element that receives the light to generate the electric charge corresponding to the amount of the received light, and

a first transistor that supplies the electric charge generated in the photoelectric conversion element to the detector as the photoelectric current according to control from the driving circuit.

The solid-state image pickup device according to item (31),

in which each of the plurality of light receiving portions further includes a second transistor that transfers the electric charge generated in the photoelectric conversion element to the generator according to control from the driving circuit, and

the generator includes

a floating diffusion layer that accumulates the electric charge transferred from any one of the plurality of light receiving portions through the second transistor,

a third transistor that discharges the electric charge accumulated in the floating diffusion layer according to control from the driving circuit,

a fourth transistor that causes the voltage signal corresponding to an electric charge amount of the electric charge accumulated in the floating diffusion layer to appear on a predetermined signal line, and

a fifth transistor that switches connection between the fourth transistor and the predetermined signal line according to control from the driving circuit.

The solid-state image pickup device according to any one of items (23) to (30),

in which each of the plurality of light receiving portions further includes

a photoelectric conversion element that receives the light to generate the electric charge corresponding to the amount of the received light,

a first transistor that supplies the electric charge generated in the photoelectric conversion element to the detector as the photoelectric current according to control from the driving circuit, and

a second transistor that transfers the electric charge generated in the photoelectric conversion element to the generator according to control from the driving circuit,

the generator includes

a floating diffusion layer that accumulates the electric charge transferred from any one of the plurality of light receiving portions through the second transistor,

a third transistor that discharges the electric charge accumulated in the floating diffusion layer according to control from the driving circuit,

a fourth transistor that causes the voltage signal corresponding to an electric charge amount of the electric charge accumulated in the floating diffusion layer to appear on a predetermined signal line, and

a fifth transistor that switches connection between the fourth transistor and the predetermined signal line according to control from the driving circuit,

the detector detects presence or absence of firing of an event on the basis of the photoelectric current, and

in a case where the detector detects firing of the event during a period in which the first transistor of each of the plurality of light receiving portions is controlled to be in an ON state, the driving circuit performs a control operation to turn OFF the first transistor of each of the light receiving portions belonging to a pixel block from which firing of the event is detected, performs a control operation to turn ON the fifth transistor, turns ON the third transistor for a certain period, and then performs a control operation to turn ON second transistors of the respective light receiving portions belonging to the pixel block for a certain period according to a predetermined order.

The solid-state image pickup device according to item (32) or (33), further including a conversion unit that converts the voltage signal appearing on the predetermined signal line into a digital value corresponding to a voltage value.

The solid-state image pickup device according to any one of items (21) to (34),

in which each of the plurality of light receiving portions includes

a photoelectric conversion element that receives the light to generate the electric charge corresponding to the amount of the received light, and

a polarizer that limits a polarization direction of the light incident on the photoelectric conversion element to the specific polarization direction.

The solid-state image pickup device according to any one of items (23) to (35),

in which each of the plurality of light receiving portions has a configuration in which the light receiving portions for respective wavelength components used to reconstruct a color of incident light are arrayed in a 2D lattice pattern according to a predetermined array.

The solid-state image pickup device according to item (36), in which the predetermined array corresponds to any one of a Bayer array, an X-Trans (registered trademark) type array, and a Quad Bayer array.

The solid-state image pickup device according to item (36) or (37), further including a wavelength selection element provided for each of the plurality of light receiving portions to transmit the light for each wavelength component.

The solid-state image pickup device according to any one of items (36) to (38), in which each pixel block includes light receiving portions, the number of which is obtained by multiplying the number of polarizers used to reconstruct polarization information of incident light by the number of wavelength components used to reconstruct a color of the incident light.

An image pickup device including

a plurality of light receiving portions, each of which receives light in a specific polarization direction to generate an electric charge corresponding to an amount of the received light,

a detector that detects a photoelectric current based on an electric charge generated in at least one of the plurality of light receiving portions,

a generator that generates a voltage signal based on the electric charge generated in each of the plurality of light receiving portions, and

a driving circuit that causes the generator to generate voltage signals based on electric charges generated in at least two of the plurality of light receiving portions, respectively, on the basis of a detection result of the photoelectric current by the detector.

REFERENCE SIGNS LIST