Image sensor and imaging device

Abstract

The image sensor comprises: a first substrate having a pixel section in which a plurality of pixels, each having a microlens and a photoelectric conversion unit, are provided in a first direction and a second direction intersecting the first direction; a second substrate having a processing circuit section in which a plurality of processing circuits for processing pixel signals output from the pixels are provided in the first direction and the second direction; and a light-shielding layer provided between the first substrate and the second substrate in the optical axis direction of the microlens to block light from the processing circuit section. Furthermore, an imaging device equipped with the above image sensor may be provided.

Description

Technical Field

[0001] The present invention relates to an imaging device and an imaging apparatus.

Background Art

[0002] An imaging device including a processing circuit such as an AD conversion unit is known (for example, Patent Document 1). Conventionally, noise caused by light generated in the AD conversion unit has been a problem. Patent Document 1 JP-A-2013-51674

Summary of the Invention

[0003] In a first aspect of the present invention, there is provided an imaging device including: a first substrate having a pixel portion in which a plurality of pixels each having a microlens and a photoelectric conversion portion are provided in a first direction and a second direction intersecting the first direction; a second substrate having a processing circuit portion in which a plurality of processing circuits for processing pixel signals output from the pixels are provided in the first direction and the second direction; and a light shielding layer provided between the first substrate and the second substrate in the optical axis direction of the microlens and shielding light from the processing circuit portion.

[0004] In a second aspect of the present invention, there is provided an imaging apparatus including the above-described imaging device.

[0005] Note that the above summary of the invention does not enumerate all the features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0007] The present invention will be described below through embodiments of the invention, but these embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0008] In this specification, the X and Y axes are orthogonal to each other, and the Z axis is orthogonal to the XY plane. The XYZ axes form a right-handed system. The direction parallel to the Z axis may be referred to as the stacking direction of the image sensor 400. In this specification, the terms "up" and "down" are not limited to the up and down directions in the direction of gravity. These terms merely refer to relative directions in the Z axis direction. In this specification, the arrangement in the X axis direction is described as a "row," and the arrangement in the Y axis direction is described as a "column," but the matrix direction is not limited to these. Also, the Z axis direction is the optical axis direction from which light from the subject is incident.

[0009] Figure 1 is a diagram illustrating the overview of the image sensor 400 according to this embodiment. The image sensor 400 captures an image of a subject. The image sensor 400 generates image data of the captured subject. The image sensor 400 comprises a first substrate 100 and a second substrate 200. As shown in Figure 1, the first substrate 100 is stacked on the second substrate 200.

[0010] The first substrate 100 has a pixel section 110. The pixel section 110 outputs a pixel signal based on incident light. The first substrate 100 is sometimes referred to as a pixel chip.

[0011] The second substrate 200 has a processing circuit section 210 and a peripheral circuit section 230. The second substrate 200 is sometimes referred to as a signal processing chip.

[0012] The processing circuit 210 receives the pixel signal output from the first substrate 100. The processing circuit 210 processes the input pixel signal. For example, the processing circuit 210 performs a process to convert an analog signal into a digital signal. Specifically, the processing circuit 210 performs a process to convert the input pixel signal into a digital signal. The processing circuit 210 may also perform other signal processing. Examples of other signal processing include noise reduction processing such as analog or digital CDS (correlated double sampling).

[0013] The processing circuit unit 210 in this example is disposed on the second substrate 200 at a position facing the pixel unit 110. That is, the processing circuit unit 210 is arranged so as to at least partially overlap the pixel unit 110 in the optical axis direction. The processing circuit unit 210 may output a control signal for controlling the driving of the pixel unit 110 to the pixel unit 110.

[0014] The peripheral circuit unit 230 controls the driving of the processing circuit unit 210. The peripheral circuit unit 230 is disposed on the second substrate 200 around the processing circuit unit 210. Also, the peripheral circuit unit 230 may be electrically connected to the first substrate 100 and control the driving of the pixel unit 110.

[0015] In addition to the first substrate 100 and the second substrate 200, the imaging device 400 may have a third substrate laminated on the second substrate 200. For example, the third substrate is a memory chip and performs image processing according to the signal output from the second substrate 200. Also, the structure of the imaging device 400 may be a back-illuminated type or a front-illuminated type. Hereinafter, an example of the back-illuminated type will be described.

[0016] FIG. 2 shows an example of a specific configuration of the pixel unit 110. In this example, an enlarged view of the pixel unit 110 and pixel blocks 120 provided in the pixel unit 110 is shown.

[0017] The pixel unit 110 has a plurality of pixel blocks 120 arranged side by side along the row direction and the column direction. The pixel unit 110 in this example has M×N (M and N are natural numbers) pixel blocks 120. In this example, the case where M is equal to N is illustrated, but M and N may be different.

[0018] The pixel block 120 has at least one pixel 112. The pixel block 120 in this example has m×n pixels 112 (m and n are natural numbers). For example, the pixel block 120 has 16×16 pixels 112. The number of pixels 112 corresponding to the pixel block 120 is not limited to this. In this example, the case where m is equal to n is illustrated, but m may be different from n. The number of pixels 112 corresponding to the pixel block 120 may also be one. The pixel block 120 has a plurality of pixels 112 connected to a common control line in the row direction. For example, each pixel 112 of the pixel block 120 is connected to a common control line so as to be set to the same exposure time. In one example, n pixels 112 arranged in the row direction are connected by a common control line.

[0019] On the other hand, among the plurality of pixel blocks 120, they may be set to different exposure times. That is, each pixel 112 of the pixel block 120 has the same exposure time, but may be set to a different exposure time in other pixel blocks 120. For example, when the pixels 112 of the pixel block 120 are connected by a common control line in the row direction, the pixels 112 of other pixel blocks 120 are commonly connected by different control lines.

[0020] The pixel block 120 is arranged corresponding to the processing block 220 described later. In the present embodiment, one pixel block 120 is arranged for one processing block 220.

[0021] The pixel 112 has a photoelectric conversion function of converting light into electric charge. The pixel 112 accumulates the photoelectrically converted electric charge. m pixels 112 are arranged side by side along the column direction and are connected to a common signal line 122. And the m pixels 112 are arranged in n columns in the row direction in the pixel block 120.

[0022] In other words, the pixel block 120 is a collection of a plurality of pixels 112 connected by a common control line. Also, it can be said that the pixel block 120 is the minimum unit of the circuit of a plurality of pixels 112 to which the same exposure time is set.

[0023] Figure 3 shows an example of the circuit configuration of pixel 112, and Figure 4 shows a schematic plan view of pixel 112 as seen from the Z direction, which is the optical axis direction. Pixel 112 comprises a photoelectric conversion unit 104, a transfer unit 123, a reset unit 126, and a pixel output unit 127. The pixel output unit 127 has an amplification unit 128 and a selection unit 129. In this example, the transfer unit 123, reset unit 126, amplification unit 128, and selection unit 129 are described as N-channel FETs, but the type of transistor is not limited to this.

[0024] The photoelectric conversion unit 104 has a photoelectric conversion function that converts light into electric charge. The photoelectric conversion unit 104 stores the photoelectrically converted charge. The photoelectric conversion unit 104 is, for example, a photodiode. The photoelectric conversion unit 104 has an injection region 106 into which impurities are injected and which has a photoelectric conversion function, and an isolation region 108 arranged around the injection region 106 to separate the injection region 106 from other elements.

[0025] The transfer unit 123 transfers the charge stored in the photoelectric conversion unit 104 to the storage unit 125. The transfer unit 123 is an example of a transfer gate that transfers charge from the photoelectric conversion unit 104. In other words, the transfer unit 123 acts as the gate, the photoelectric conversion unit 104 as the source, and the storage unit 125 as the drain, and these together constitute a so-called transfer transistor. The gate terminal of the transfer unit 123 is connected to a local transfer control line 141 for each pixel block 120 to input the control signal φTX1.

[0026] The storage unit 125 receives charge from the photoelectric conversion unit 104 via the transfer unit 123. The storage unit 125 is an example of floating diffusion (FD).

[0027] The reset unit 126 discharges the charge from the storage unit 125 to a power supply wiring to which a predetermined power supply voltage VDD is supplied. The gate terminal of the reset unit 126 is connected to a global reset control line 143 spanning multiple pixel blocks 120 for inputting a reset control signal φRST.

[0028] The pixel output unit 127 outputs a signal based on the potential of the storage unit 125 to the signal line 122. The pixel output unit 127 includes an amplification unit 128 and a selection unit 129. The gate terminal of the amplification unit 128 is connected to the storage unit 125, the drain terminal is connected to the power supply wiring to which the power supply voltage VDD is supplied, and the source terminal is connected to the drain terminal of the selection unit 129.

[0029] The selection unit 129 controls the electrical connection between the pixel 112 and the signal line 122. When the selection unit 129 electrically connects the pixel 112 and the signal line 122, a pixel signal is output from the pixel 112 to the signal line 122. The gate terminal of the selection unit 129 is connected to a global selection control line 144 spanning multiple pixel blocks 120 for inputting the selection control signal φSEL. The source terminal of the selection unit 129 is connected to the load current source 121.

[0030] The load current source 121 supplies current to the signal line 122. The load current source 121 may be provided on the first substrate 100 or on the second substrate 200.

[0031] Hereafter, the charge stored in the photoelectric conversion unit 104, the charge transferred to the storage unit 125, and the signal based on the potential of the storage unit 125, or these collectively, may be referred to as the pixel signal.

[0032] In addition, each pixel 112 includes at least one photoelectric conversion unit 104 and a pixel output unit 127 which acts as a readout unit that reads the image signal from the at least one photoelectric conversion unit 104 to the signal line 122. The pixel 112 can also be described as the smallest unit of the circuit that outputs the pixel signals constituting the image to the signal line 122.

[0033] Pixel 112 further has a light-shielding layer 150 provided so as to cover the photoelectric conversion unit 104 when viewed from the Z direction, i.e., the optical axis direction. The light-shielding layer 150 will be described later.

[0034] Figure 5 shows a more specific example of the configuration of the processing circuit unit 210. In this example, the processing circuit unit 210 and an enlarged view of the processing block 220 provided in the processing circuit unit 210 are shown.

[0035] The processing circuit unit 210 has processing blocks 220 arranged in a row and column direction. In this example, the processing circuit unit 210 has M × N processing blocks 220.

[0036] The processing blocks 220 are positioned at locations corresponding to the pixel blocks 120. For example, the processing blocks 220 and pixel blocks 120 are positioned so that they overlap when viewed from the optical axis direction. In this case, the areas of the processing blocks 220 and pixel blocks 120 may be approximately the same, including the margins between adjacent blocks.

[0037] The processing block 220 controls the driving of the corresponding pixel block 120. For example, the processing block 220 controls the exposure time of the pixel block 120. The processing block 220 also has processing circuits such as an AD converter and processes the signals output by the pixel block 120. In one example, the processing block 220 converts the analog pixel signal output from the corresponding pixel block 120 into a digital signal. The processing block 220 in this example includes an exposure control unit 10, a pixel driving unit 20, a fusion unit 30, a signal conversion unit 40, and a signal output unit 50.

[0038] The exposure control unit 10 controls the exposure of multiple pixels 112. The exposure control unit 10 generates signals to control the exposure time of the pixels 112. In one example, the exposure control unit 10 controls the exposure time for each pixel block 120 by adjusting at least one of the start timing or end timing of the exposure.

[0039] The pixel drive unit 20 is electrically connected to a plurality of pixels 112. Based on a signal from the exposure control unit 10, the pixel drive unit 20 selects and drives any pixel 112 from the plurality of pixels 112. The pixel drive unit 20 is positioned in a location corresponding to m pixels 112 arranged in the column direction. The image sensor 400 can expand its dynamic range because the exposure time can be set for each pixel block 120 according to the intensity of the incident light.

[0040] The joint 30 joins the first substrate 100 and the second substrate 200. The joint 30 inputs the pixel signal received from the first substrate 100 to the signal conversion unit 40. The joint 30 is provided in accordance with n pixels 112 arranged in the row direction, and inputs the pixel signal to the signal conversion unit 40 column by column.

[0041] The signal conversion unit 40 converts the analog signal output by the pixel unit 110 into a digital signal. In this example, the signal conversion unit 40 converts the analog pixel signal into a digital signal. The signal conversion unit 40 sequentially converts the analog signals from m pixels 112 arranged in the column direction into digital signals. The signal conversion unit 40 also converts the analog signals from n pixels 112 arranged in the row direction into digital signals in parallel. This can also be described as a so-called column ADC method for one pixel block 120.

[0042] The signal output unit 50 receives a digital signal from the signal conversion unit 40. In one example, the signal output unit 50 temporarily stores the digital signal. The signal output unit 50 may have a latch circuit for storing the digital signal.

[0043] Alternatively, instead of providing one processing block 220 for each pixel block 120, one processing block 220 may be provided for N pixel blocks 120 (where N is a natural number greater than or equal to 2). N pixel blocks 120 corresponding to one processing block are sometimes referred to as a pixel block group. For example, two pixel blocks 120 arranged side-by-side in the column direction may be treated as one pixel block group, and one processing block 220 may be provided for each of these groups. In this case, the processing block 220 may control the exposure time for each pixel block 120.

[0044] Furthermore, the processing block 220 is electrically connected to at least one pixel block 120 and can be described as the smallest unit of circuitry that processes the pixel signals of that at least one pixel block 120. Also, the processing circuit section 210 can be described as being composed of a group of processing blocks 220.

[0045] Figure 6 schematically shows a cross-section of the image sensor 400. In particular, Figure 6 shows a cross-section passing through the photoelectric conversion unit 104 and the transfer unit 123 at pixel 112. However, Figure 6 is simplified for illustrative purposes, and unless otherwise specified, the position, size, and number of each component are merely schematic examples.

[0046] The first substrate 100 has a microlens 180, a planarization layer 181, a color filter 182, a planarization layer 183, a pixel formation region 187, a gate oxide film 188, and a wiring layer 190 along the optical axis direction. A light-shielding layer 184 is provided on the planarization layer 183. The pixel formation region 187 includes the components of the pixel 112, such as a photoelectric conversion unit 104 and a storage unit 125, as well as an element isolation unit 186. The wiring layer 190 has wiring 192 and a light-shielding layer 150.

[0047] The second substrate 200 has a wiring layer 252, a gate oxide film 256, a circuit region 258, and a substrate 259 along the optical axis direction. Wiring 254 is arranged in the wiring layer 252. The circuit region 258 contains elements of the processing block 220, such as transistors included in the signal conversion unit 40. These elements may be arranged across other regions. For the sake of explanation, Figure 6 shows a transistor 260 included in the signal conversion unit 40 as an example of such an element. The first substrate 100 and the second substrate 200 are electrically connected at the junction surface 250 by opposing bumps 193 and 251.

[0048] The microlens 180 focuses the incident light onto the photoelectric conversion unit 104. The color filter 182 transmits a predetermined wavelength range, i.e., color, of the light incident on the microlens 180. The light-shielding layer 184 is a film that does not transmit visible light, such as black or metallic, and avoids crosstalk between adjacent pixels 112 in the matrix direction. The element isolation unit 186 is an isolation band that avoids electrical interference with adjacent pixels in the matrix direction.

[0049] In the above configuration, an active element included in the processing block 220, such as the transistor 260 included in the signal conversion unit 40, may unintentionally function as a light-emitting diode and emit light during operation. In this case, when the light emitted from the transistor 260 enters the photoelectric conversion unit 104, it is photoelectrically converted and becomes noise in the pixel signal of the light from the subject that enters through the microlens 180. For example, the transistor 260 may emit infrared light with a wavelength of about 1000 nm, and this wavelength is within the sensitivity range of the photoelectric conversion unit 104.

[0050] Therefore, in this embodiment, a light-shielding layer 150 is provided that is positioned on the side of the second substrate 200 that is closer to the photoelectric conversion unit 104, and that at least partially overlaps the photoelectric conversion unit 104 in the optical axis direction. In the example shown in Figure 6, the light-shielding layer 150 completely covers the photoelectric conversion unit 104 in the optical axis direction.

[0051] The light-shielding layer 150 is preferably one that blocks light in the wavelength range to which the photoelectric conversion unit 104 is sensitive. The light-shielding layer 150 may be made of metal. If the first substrate 100 is made of silicon, the light-shielding layer 150 may be made of polysilicon instead of metal. The light-shielding layer 150 may also be provided separately from each element of the pixel 112, or the position and size of a part of any element may be adjusted to form the light-shielding layer 150. In this case, for example, the light-shielding layer 150 may be an extension of the transfer unit 123. In other words, the light-shielding layer 150 is integrally connected to the gate terminal of the transfer unit 123.

[0052] According to this embodiment, the light-shielding layer 150 blocks light from the processing block 220, such as the transistor 260. Therefore, noise in the pixel signal caused by this light can be reduced. The light-shielding layer 150 also has the effect of blocking stray light that enters the photoelectric conversion unit 104 from the microlens 180, passes through the wiring layer 190, and is reflected into the adjacent photoelectric conversion unit 104.

[0053] Figure 7 schematically shows a cross-section of a modified image sensor 400. In Figure 7, the second substrate 200 is omitted, and the same components as those in the first substrate 100 in Figure 6 are given the same reference numerals and their descriptions are omitted.

[0054] In Figure 7, in addition to the light-shielding layer 150 in Figure 6, a black siliconized layer 152 is provided on the surface of the light-shielding layer 150 on the side facing the second substrate 200. The black siliconized layer 152 is formed by reducing the reflectivity of infrared and visible light (in other words, it is black to these lights) by, for example, creating nano-order irregularities on the surface of the silicon layer. The black siliconized layer 152 prevents light from the processing block 220 from being absorbed and becoming stray light.

[0055] A silicide layer may be provided instead of the black siliconized layer 152. The silicide layer is, for example, a layer alloyed with silicon and a metal, which has increased reflectivity for infrared and visible light. The silicide layer can reflect light from the processing block 220 and more reliably prevent it from entering the photoelectric conversion unit 104.

[0056] Figure 8 schematically shows a cross-section of yet another modified image sensor 400, and Figure 9 shows a timing chart for reading out pixel signals in the image sensor 400 of Figure 8. In Figure 8 as well, the second substrate 200 is omitted, and the same reference numerals are used for components with the same configuration as the first substrate 100 in Figure 6, and their explanations are omitted.

[0057] In Figure 8, the light-shielding layer 150 is electrically connected to the storage unit 125 by the wiring unit 154. Therefore, when photoelectric conversion occurs in the light-shielding layer 150 due to light incident on the light-shielding layer 150 from the processing block 220, the charge resulting from this photoelectric conversion is stored in the storage unit 125.

[0058] In other words, as shown in Figure 9, during the storage time determined by the control signal φTX1, the charge from the light-shielding layer 150 is stored as the charge signal φFD. However, before the transfer of the charge signal φPD from the photoelectric conversion unit 104, the charge signal φFD of the storage unit 125 is reset by the reset signal φRST. Therefore, the charge signal φFD corresponding to the charge signal φPD of the photoelectric conversion unit 104 is transferred and read out without being affected by the charge from the light-shielding layer 150.

[0059] Figure 10 shows a schematic plan view of another example of a pixel 112 as seen from the Z direction, which is the optical axis direction, and Figure 11 schematically shows a cross-section of an image sensor 400 using the pixel 112 of Figure 10. In Figure 11 as well, the second substrate 200 is omitted, and the same components as the first substrate 100 in Figure 6 are given the same reference numerals and their explanations are omitted.

[0060] In Figures 10 and 11, the light-shielding layer 156 is electrically insulated from the transfer unit 123. Instead, it has a connecting wire 146 that electrically connects the light-shielding layer 156 to the power supply potential.

[0061] The light-shielding layer 156 does not cover a portion of the photoelectric conversion unit 104 that is close to the transfer unit 123 when viewed from the optical axis direction, but it covers most of the rest. Therefore, in the examples of Figures 10 and 11, the light-shielding layer 156 can block most of the light from the processing block 220, such as the transistor 260, thereby reducing noise in the pixel signal caused by that light. In addition, since the light-shielding layer 156 is electrically connected to the power supply potential, the charge photoelectrically converted by the light-shielding layer 156 can be discharged through the connecting wiring 146. Therefore, the influence of the charge photoelectrically converted by the light-shielding layer 156 on the pixel signal can be suppressed.

[0062] Alternatively, instead of connecting the light-shielding layer 156 to the power supply potential, it may be connected to the ground potential via the connecting wiring 146. As another example, a negative voltage bias may be applied to the light-shielding layer 156. This helps to prevent dark current. As yet another example, other active elements that selectively apply voltage to the light-shielding layer 156 may be provided.

[0063] Figure 12 shows an example of electrical operation when other active elements are connected to the light-shielding layer 156. Figure 12(a) shows the charge accumulation of the photoelectric conversion unit 104, and (b) shows the charge transfer.

[0064] As shown in Figure 12(a), a negative voltage is applied to the transfer unit 123 during accumulation, while no voltage is applied to the light-shielding layer 156. This allows charge to accumulate in the photoelectric conversion unit 104.

[0065] As shown in Figure 12(b), a positive voltage is applied to the transfer unit 123 during transfer, while a negative voltage is applied to the light-shielding layer 156. This ensures that the charge accumulated in the photoelectric conversion unit 104 is more reliably transferred to the storage unit 125 via the transfer unit 123.

[0066] Figure 13 shows a schematic plan view of yet another example of pixel 112 as seen from the Z direction, which is the optical axis direction, and Figure 14 schematically shows a cross-section of the image sensor 400 using the pixel 112 of Figure 13. In Figure 14 as well, the second substrate 200 is omitted, and the same reference numerals are used for components that are the same as those of the first substrate 100 in Figure 6, and their explanations are omitted.

[0067] In Figures 13 and 14, in addition to the light-shielding layer 150 in Figure 6, there is another light-shielding layer 158 on the side of the second substrate 200 that is closer to the light-shielding layer 150. The light-shielding layer 158 overlaps at least partially with the photoelectric conversion unit 104 and the light-shielding layer 150 in the direction of the optical axis.

[0068] Furthermore, the light-shielding layer 158 in this example is electrically connected to the transfer unit 123. On the other hand, the light-shielding layer 150 is electrically connected to the connecting wiring 146. In this example, since the light-shielding layers 150 and 158 are double-layered, light from the processing block 220, such as the transistor 260, can be more reliably blocked, thereby reducing noise in the pixel signal caused by that light. In addition, the charge accumulated in the light-shielding layer 150 can be discharged via the connecting wiring 146, or used as a transfer aid for the photoelectric conversion unit 104.

[0069] The light-shielding layers 150 etc. shown in Figures 6 to 14 may be combined. Alternatively, instead of connecting each light-shielding layer to the transfer unit 123, it may be connected to other elements of the pixel 112, such as the reset unit 126. Note that if the light-shielding layers 150 etc. are electrically connected to the storage unit 125, it is equivalent to substantially increasing the capacity of the storage unit 125. Therefore, charge overflow in the storage unit 125 becomes less likely.

[0070] In addition, in any of the above embodiments, a discharge unit may be provided in the pixel 112. The discharge unit discharges the charge accumulated in the photoelectric conversion unit 104 to the power supply wiring to which the power supply voltage VDD is supplied. As another example, the transfer unit 123 may be omitted. In that case, the accumulation unit 125 will no longer function as a floating diffusion. Also, the accumulation unit 125 and the pixel output unit 127 may be shared with other pixels. Furthermore, the pixel 112 may be composed of multiple photoelectric conversion units 104 and transfer units 123.

[0071] Furthermore, in any of the above embodiments, the exposure control unit 10 and the pixel driving unit 20 may not be provided in the processing block 220, and reading may be performed mainly for each processing block 220 and conversion may be performed by the signal conversion unit 40. In this case, the exposure time of the pixels 112 is controlled not for each pixel block 120, but for the pixel unit 110 as a whole.

[0072] Figure 15 is a block diagram showing an example configuration of an imaging device 500 according to an embodiment. The imaging device 500 comprises an image sensor 400, a system control unit 501, a drive unit 502, a photometer 503, a work memory 504, a recording unit 505, a display unit 506, a drive unit 514, and a photographic lens 520.

[0073] The imaging lens 520 guides the subject light beam incident along the optical axis OA to the image sensor 400. The imaging lens 520 is composed of multiple optical lens groups and forms an image of the subject light beam from the scene near its focal plane. The imaging lens 520 may be an interchangeable lens that can be attached to and detached from the imaging device 500. In Figure 15, the imaging lens 520 is represented by a single hypothetical lens positioned near the pupil.

[0074] The drive unit 514 drives the photographic lens 520. In one example, the drive unit 514 moves the optical lens group of the photographic lens 520 to change the focus position. The drive unit 514 may also drive the iris diaphragm within the photographic lens 520 to control the amount of light beam incident on the image sensor 400.

[0075] The drive unit 502 has a control circuit that performs charge accumulation control such as timing control and area control of the image sensor 400 according to instructions from the system control unit 501. The operation unit 508 receives instructions from the imager via a release button or the like.

[0076] The image sensor 400 passes pixel signals to the image processing unit 511 of the system control unit 501. The image processing unit 511 uses the work memory 504 as a workspace to generate image data after performing various image processing steps. For example, when generating image data in JPEG file format, it generates a color video signal from the signal obtained by the Bayer array and then performs compression processing. The generated image data is recorded in the recording unit 505 and converted into a display signal, which is then displayed in the display unit 506 for a preset time.

[0077] Prior to the series of shooting sequences that generate image data, the photometering unit 503 detects the brightness distribution of the scene. The photometering unit 503 includes, for example, an AE sensor with about 1 million pixels. The calculation unit 512 of the system control unit 501 receives the output of the photometering unit 503 and calculates the brightness of each region of the scene.

[0078] The calculation unit 512 determines the shutter speed, aperture value, and ISO sensitivity according to the calculated brightness distribution. The photometering unit 503 may also be integrated into the image sensor 400. The calculation unit 512 also performs various calculations for operating the imaging device 500. The drive unit 502 may be partially or entirely mounted on the image sensor 400. Part of the system control unit 501 may also be mounted on the image sensor 400.

[0079] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0080] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0081] 10 Exposure control unit, 20 Pixel drive unit, 30 Bonding unit, 40 Signal conversion unit, 50 Signal output unit, 100 First substrate, 104 Photoelectric conversion unit, 106 Injection area, 108 Separation area, 110 Pixel unit, 112 Pixel, 120 Pixel block, 121 Load current source, 122 Signal line, 123 Transfer unit, 125 Storage unit, 126 Reset unit, 127 Pixel output unit, 128 Amplification unit, 129 Selection unit, Selection unit, 141 Transfer control line, 143 Reset control line, 144 Selection control line, 146 Connection wiring, 150 Light-shielding layer, 152 Black siliconized layer, 154 Wiring unit, 156 Light-shielding layer, 158 Light-shielding layer, 180 Microlens, 181, 183 Planarization layer, 182 Color filter, 184 Light-shielding layer (between pixels), 186 Element separation section, 187 Pixel formation area, 188 Gate oxide film, 190 Wiring layer, 192 Wiring, 193, 251 Bump, 200 Second substrate, 210 Processing circuit section, 220 Processing block, 250 Bonding surface, 252 Wiring layer, 254 Wiring, 256 Gate oxide film, 258 Circuit area, 259 Substrate, 260 Transistor, 400 Image sensor, 500 Imaging device, 501 System control section, 502 Drive section, 503 Photometer section, 504 Work memory, 505 Recording section, 506 Display section, 508 Operation section, 511 Image processing section, 512 Calculation section, 514 Drive section, 520 Shooting lens

Claims

[Claim 1] A first substrate having a pixel section including a first photoelectric conversion unit that converts light into electric charge, and a second photoelectric conversion unit that converts light into electric charge and is arranged in the row direction alongside the first photoelectric conversion unit, A second substrate laminated with the first substrate, having a processing circuit section on which a first pixel control unit that outputs a first control signal for controlling the storage time for storing the charge converted by the first photoelectric conversion unit, a first conversion unit that converts a first signal based on the charge converted by the first photoelectric conversion unit into a first digital signal, a second pixel control unit that outputs a second control signal for controlling the storage time for storing the charge converted by the second photoelectric conversion unit, and a second conversion unit that converts a second signal based on the charge converted by the second photoelectric conversion unit into a second digital signal is arranged. Equipped with, The processing circuit section is positioned opposite the pixel section in the stacking direction in which the first substrate and the second substrate are stacked. The first substrate has a light-shielding portion that blocks light from the second substrate side toward the first substrate side and is positioned between the first photoelectric conversion unit and the second substrate in the stacking direction, and a light-shielding portion that blocks light from the second substrate side toward the first substrate side and is positioned between the second photoelectric conversion unit and the second substrate in the stacking direction. Image sensor.

Images