camera device

Abstract

This invention relates to an imaging device. The imaging device may include: a first substrate, the first substrate including: a plurality of pixels, the plurality of pixels including a first pixel, the first pixel including a first conversion element, and a first portion of a differential amplifier circuit, the first portion of the differential amplifier circuit being connected to the first conversion element via a transfer transistor, a floating diffuser, and a capacitor as a clamping capacitor; and a second substrate, the second substrate laminated to the first substrate, the second substrate including: a second portion of the differential amplifier circuit, the first portion of the differential amplifier circuit being connected to the second portion of the differential amplifier circuit; wherein the first portion of the differential amplifier circuit and the second portion of the differential amplifier circuit are electrically connected via a metal bonding electrode, a capacitor is connected in series between the floating diffuser and a first input of the differential amplifier circuit, and a feedback transistor is connected to the first input of the first portion of the differential amplifier circuit and configured to initialize the differential amplifier circuit.

Description

[0001] This application is a divisional application of patent application No. 201880047158.0, filed on June 27, 2018, entitled "Camera Device". Technical Field

[0002] This disclosure relates to camera devices. Background Technology

[0003] Technology for obtaining high-quality images using imaging elements has been developed. Examples of techniques for obtaining high-quality images by adaptively changing the conversion efficiency when charge obtained through photoelectric conversion is converted into a voltage signal include the technique described in Patent Document 1 below.

[0004] Reference List

[0005] Patent documents

[0006] Patent Document 1: JP 2016-92661A Summary of the Invention

[0007] Technical issues

[0008] For example, in the imaging element described in Patent Document 1, a voltage signal obtained through photoelectric conversion is input to a differential amplifier circuit, and the voltage signal is amplified. The amplified voltage signal is then converted into a digital signal by an analog-to-digital converter (AD converter) provided for each pixel. A voltage signal is obtained by accumulating the charge obtained through photoelectric conversion using a floating diffusion layer and converting it into a voltage signal.

[0009] In existing configurations, an AD converter is used for each pixel or multiple pixels. The voltage signal obtained through photoelectric conversion is input to a differential amplifier circuit and amplified. When the differential amplifier circuit performs an automatic zero-reset operation, the floating diffusion layer is reset. In these existing configurations, due to the voltage drop occurring in the transistors included in the output stage of the differential amplifier circuit, the reset potential of the floating diffusion layer is necessarily lower compared to the source follower readout configuration. Examples of voltage drops occurring in the transistors included in the output stage of the differential amplifier circuit include a voltage drop of approximately 0.30V to 0.45V. Therefore, the above configuration reduces the dynamic range of the floating diffusion layer.

[0010] This disclosure presents a novel and improved imaging device that prevents the reduction of the dynamic range of the floating diffusion layer.

[0011] Solutions to technical problems

[0012] According to this disclosure, a camera device is provided, comprising a camera unit having a plurality of pixels, each pixel having: a conversion element for converting incident light into photoelectrons; a floating diffusion layer electrically connected to the conversion element and converting the photoelectrons into voltage signals; a differential amplifier circuit electrically connected to the floating diffusion layer, including an amplifying transistor that is input to the potential of the floating diffusion layer and amplifies the potential of the floating diffusion layer; a feedback transistor electrically connected to the amplifying transistor and initializing the differential amplifier circuit; a clamping capacitor connected in series between the floating diffusion layer and the amplifying transistor; and a reset transistor connected in parallel between the floating diffusion layer and the clamping capacitor and initializing the potential of the floating diffusion layer.

[0013] Beneficial effects of the present invention

[0014] This disclosure can prevent the reduction of the dynamic range of the floating diffusion layer.

[0015] The above effects are not limiting and may be used in conjunction with or in place of the above effects to produce any effect described in this specification or any other effect gleaned from this specification. Attached Figure Description

[0016] Figure 1 This is an explanatory diagram illustrating an exemplary construction of a camera device according to the first embodiment.

[0017] Figure 2 This is an illustrative diagram illustrating an exemplary construction of pixels according to the first embodiment.

[0018] Figure 3 This is an explanatory diagram illustrating exemplary operation of pixels according to the first embodiment.

[0019] Figure 4 This is an illustrative diagram illustrating another example of the construction of pixels according to the first embodiment.

[0020] Figure 5 This is a schematic illustration of an exemplary layout of pixels according to the first embodiment.

[0021] Figure 6 This is a schematic illustration of an exemplary layout of pixels according to the first embodiment.

[0022] Figure 7A This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0023] Figure 7B This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0024] Figure 7C This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0025] Figure 7D This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0026] Figure 7E This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0027] Figure 7F This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0028] Figure 7G This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0029] Figure 7H This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0030] Figure 7I This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0031] Figure 7J This is an explanatory diagram of an exemplary layout of pixels according to the first embodiment.

[0032] Figure 8 This is an explanatory diagram illustrating an exemplary construction of pixels according to the second embodiment.

[0033] Figure 9 This is an illustrative diagram illustrating another example of the construction of pixels according to the second embodiment.

[0034] Figure 10 This is a schematic illustration of an exemplary layout of pixels according to the second embodiment.

[0035] Figure 11 This is an explanatory diagram illustrating an exemplary construction of pixels according to the third embodiment.

[0036] Figure 12 This is an illustrative diagram illustrating another example of the construction of pixels according to the third embodiment.

[0037] Figure 13 This is an explanatory diagram of the layout of pixel P according to the third embodiment.

[0038] Figure 14 This is an illustrative diagram of an exemplary layout of a pixel array of a camera device according to another embodiment.

[0039] Figure 15 This is an illustrative diagram of another example of the layout of the pixel array of a camera device according to another embodiment.

[0040] Figure 16 This is a block diagram illustrating an exemplary structure of a vehicle control system.

[0041] Figure 17 This is an illustrative diagram of an exemplary installation location for an external information detector and camera unit. Detailed Implementation

[0042] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. In this specification and the drawings, elements having substantially the same function are indicated by the same reference numerals to omit redundant descriptions.

[0043] In the following text, “one component and another component are connected to each other” means “one component and another component are electrically connected to each other without involving any other component” or “one component and another component are electrically connected to each other via any other component”.

[0044] The following items will be described in the following order.

[0045] 1. The camera device according to this embodiment

[0046] [1] Overview of the camera device according to this embodiment

[0047] [2] Camera device according to the first embodiment

[0048] [3] Camera device according to the second embodiment

[0049] [4] Camera device according to the third embodiment

[0050] [5] Camera device according to another embodiment

[0051] [6] Effects produced by the camera device according to this embodiment

[0052] 2. Application example of the camera device according to this embodiment

[0053] (The camera device according to this embodiment)

[0054] [1] Overview of the camera device according to this embodiment

[0055] As described above, in the existing structure, an AD converter is provided for each pixel or for multiple pixels. The voltage signal obtained by photoelectric conversion is input to the differential amplifier circuit and amplified. The reset potential of the floating diffusion layer decreases by an amount corresponding to the voltage drop that occurs in the differential amplifier circuit, and the dynamic range of the floating diffusion layer decreases.

[0056] In view of this situation, the camera device according to this embodiment has a structure that prevents the voltage drop occurring in the differential amplifier circuit from affecting the reset potential of the floating diffusion layer and thus prevents a reduction in the dynamic range of the floating diffusion layer.

[0057] More specifically, the pixels of the imaging device according to this embodiment have the following configuration: "a clamping capacitor is connected in series between the input terminal of the differential amplifier circuit and the floating diffusion layer, while a reset transistor for initializing the potential of the floating diffusion layer is connected in parallel between the floating diffusion layer and the clamping capacitor." With this configuration, the potential of the floating diffusion layer can be initialized while preventing voltage drops occurring in the differential amplifier circuit from affecting the reset potential of the floating diffusion layer. This configuration prevents voltage drops occurring in the differential amplifier circuit from affecting the reset potential of the floating diffusion layer, thereby preventing a reduction in the dynamic range of the floating diffusion layer.

[0058] The construction of the camera device according to this embodiment will now be described.

[0059] [2] Camera device according to the first embodiment

[0060] The camera device according to the first embodiment will be described first. Figure 1 This is an explanatory diagram illustrating an exemplary construction of the camera device 100 according to the first embodiment.

[0061] For example, the camera device 100 includes a camera unit 102 having a plurality of pixels P that respectively perform photoelectric conversion and a driver 104 for driving pixel circuitry. The camera device 100 is driven by power supplied by an internal power source such as a battery or by power supplied by an external power source.

[0062] The camera unit 102 includes a pixel array in which a plurality of pixels P are arranged in a matrix. Pixels P are electrically connected to driver 104 via signal lines. Although for convenience... Figure 1 An example is shown in which each pixel is connected to the driver 104 via a single signal line, but the driver 104 and each pixel P can be connected to each other via multiple signal lines. In pixel P, the accumulation of signal charge corresponding to the incident light, the initialization of pixel P, etc., are performed by control signals transmitted from the driver 104 via the signal lines.

[0063] For example, the camera unit 102 includes one substrate or multiple laminated substrates. When the camera unit 102 includes laminated substrates, at least the conversion element (described below), the floating diffusion layer (described below), and the reset transistor (described below) included in the pixel P are disposed on the same substrate. The following example illustrates the case where the camera unit 102 includes two laminated substrates.

[0064] The following will describe an exemplary construction of pixel P according to the first embodiment.

[0065] The structure of the camera device according to the first embodiment is not limited to... Figure 1 The example shown.

[0066] For example, the camera device according to the first embodiment does not necessarily include a driver 104, and each pixel P can be driven by a control signal transmitted from an external driver via a signal line.

[0067] The imaging device according to the first embodiment may further include a conversion unit (not shown) that converts the analog signal output from the pixel P included in the imaging unit 102 into a digital signal. The conversion unit (not shown) has a conversion circuit that converts the analog signal into a digital signal for each pixel P or multiple pixels P, and the conversion circuit converts the analog signal output from the pixel P into a digital signal.

[0068] An example of the conversion circuit according to this embodiment includes an analog-to-digital converter (ADC) having a fixed gain for the analog signal to be converted into a digital signal. Examples of ADCs include any type of ADC, such as a successive approximation ADC. The conversion circuit according to this embodiment is capable of adjusting the gain of the analog signal to be converted into a digital signal (capable of switching the gain of the analog signal).

[0069] The following will be based on Figure 1 Taking the camera device 100 shown as an example, an exemplary structure of the pixel P of the camera device 100 will be described.

[0070] The following examples illustrate cases where the transistors included in pixel P are either N-channel or P-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). The transistors included in pixel P are not limited to MOSFETs. For example, the transistors included in pixel P can be any field-effect transistor (FET), such as a bipolar transistor or a thin-film transistor (TFT). The polarity of the transistors included in pixel P is not limited to the examples below and can be changed according to the signal to be applied to the control terminal of each transistor.

[0071] [2-1] Exemplary construction of pixel P according to the first embodiment

[0072] Figure 2 This is an explanatory diagram illustrating an exemplary construction of pixel P according to the first embodiment. Figure 2 An example is shown in which pixel P includes two substrates (including a first substrate B1 and a second substrate B2).

[0073] For example, according to the first embodiment, pixel P includes a conversion element D, a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0074] The transfer transistor Tr transfers the charge corresponding to the conversion of the incident light through the conversion element D to the floating diffuser layer Cfd.TG Connected between the conversion element D and the floating diffusion layer Cfd. Transfer transistor Tr TG By applying a control signal TG to switch the transistor to the on state (conduction state), the charge corresponding to the conversion of the incident light through the conversion element D is transferred to the floating diffusion layer Cfd. In the following text, the transfer transistor Tr... TG It can be represented as "TG".

[0075] The overflow drain transistor Tr transfers charge to the overflow drain of OFD. OFG It is connected between the switching element D and the overflow drain OFD that releases charge. Overflow drain transistor Tr OFG By applying a control signal OFG to turn it on, the charge corresponding to the conversion of the incident light through the conversion element D is transferred to the overflow drain OFD. In the following text, the overflow drain transistor Tr... OFG This can be represented as "OFG". Excess charge from the conversion element D can also be transferred via the transfer transistor Tr. TG and reset transistor Tr RST The excess charge from the conversion element D is released to the power supply terminal (VDD). As mentioned above, when the excess charge from the conversion element D is released to the power supply terminal, the step of releasing the excess charge can be omitted. Figure 2 OFG and OFD are shown.

[0076] The conversion element D converts incident light into photoelectrons. Examples of the conversion element D include any light-receiving element capable of converting incident light into photoelectrons, such as a photodiode.

[0077] The floating diffusion layer Cfd is connected to the conversion element D and converts the photoelectrons converted by the conversion element D into a voltage signal. The floating diffusion layer Cfd serves to accumulate the charge transferred from the conversion element D, convert the accumulated charge into a voltage signal, and output it.

[0078] A differential amplifier circuit DA is a differential amplifier circuit with a general structure that includes transistors. The differential amplifier circuit DA includes an amplifying transistor Tr connected to the floating diffusion layer Cfd and inputting a voltage signal (the potential of the floating diffusion layer Cfd, hereinafter the same) converted by the floating diffusion layer Cfd. AMP "and "the reference transistor Tr that is input to the reference signal (example control signal)" REF ", amplifier transistor Tr AMP and reference transistor Tr REF The transistor acts as an input stage to amplify the voltage signal. (Tr is the amplifying transistor.) AMP The control terminal is connected to the floating diffusion layer Cfd via a clamping capacitor Ccl. The differential amplifier circuit DA includes transistors Tr... OUT1 and Tr OUT2These are the transistors included in the output stage of a differential amplifier circuit. In the following text, the amplifying transistor Tr... AMP It can be represented as "AMP", while the reference transistor Tr REF It can be represented as "REF".

[0079] Feedback transistor Tr FB Connected to amplifying transistor Tr AMP And initialize the differential amplifier circuit DA. Feedback transistor Tr FB It turns on, thereby amplifying the transistor Tr. AMP The control terminal and the other terminal are connected to each other, amplifying the transistor Tr. AMP The control terminal potential becomes the initial potential of the differential amplifier circuit DA, and the differential amplifier circuit DA is initialized. In the following text, when the feedback transistor Tr... FB When switched to the ON state, the operation of the differential amplifier circuit DA can be represented as "automatic zeroing operation".

[0080] Clamping capacitor Ccl is connected in series with floating diffusion layer Cfd and amplifying transistor Tr. AMP Between. Examples of clamping capacitors Ccl include capacitive elements such as line-to-line capacitance and capacitors. The clamping capacitor Ccl is configured to be connected to the amplifying transistor Tr. AMP The control terminal capacitor and the capacitor attached to the amplifier transistor Tr AMP The line-to-line capacitance at the control terminal is larger than a sufficiently large capacitor.

[0081] Reset transistor Tr RST A parallel connection is made between the floating diffusion layer Cfd and the clamping capacitor Ccl, and the potential of the floating diffusion layer Cfd is initialized. Reset transistor Tr RST It is switched to the on state to initialize the potential of the floating diffusion layer Cfd.

[0082] Figure 3 This is an illustrative diagram of exemplary operation in pixel P according to the first embodiment. For example, provided by driver 104 (or an external driver). Figure 3 The various control signals shown.

[0083] The following section first explains the initialization of the potential of the floating diffusion layer Cfd and the operation of transferring charge from the conversion element D to the floating diffusion layer Cfd.

[0084] like Figure 3 As shown, in pixel P, when the differential amplifier circuit DA is performing an automatic zeroing operation (when the feedback transistor Tr... FB When in the ON state, the reset transistor Tr RST It turns on, and the potential of the floating diffusion layer Cfd is initialized. During this process, the amplifying transistor Tr...AMP The control terminal (connected to the amplifying transistor Tr in the floating diffusion layer Cfd) AMP The terminal of the differential amplifier circuit (DA) is fixed at its initial potential.

[0085] After the potential of the floating diffusion layer Cfd is initialized (in the reset transistor Tr...) RST After changing from the on state to the off state (non-conducting state), the automatic zeroing operation of the differential amplifier circuit DA in pixel P ends.

[0086] After the automatic zeroing operation of the differential amplifier circuit DA is completed, the transfer transistor Tr... TG When the light is switched on, the conversion element D and the floating diffusion layer Cfd are connected to each other, and the charge corresponding to the conversion of the incident light through the conversion element D is transferred to the floating diffusion layer Cfd.

[0087] The following describes the operation when detecting the voltage signal detected by the floating diffusion layer Cfd.

[0088] like Figure 3 As shown, after performing the charge transfer from the conversion element D to the floating diffusion layer Cfd (in the transfer transistor Tr... TG After changing from the on state to the off state), the feedback transistor Tr FB It is in the off state, and the amplifying transistor Tr is in the amplifying state. AMP The control terminal (connected to the amplifying transistor Tr in the floating diffusion layer Cfd) AMP Electrical floating occurs at the terminals. During this process, the voltage signal obtained by the floating diffusion layer Cfd is applied to the amplifying transistor Tr. AMP The control terminal detects the voltage signal obtained by the floating diffusion layer Cfd in pixel P.

[0089] It should be understood that examples of various control signals to be provided to pixel P according to the first embodiment are not limited to... Figure 3 The example shown.

[0090] For example, pixel P according to the first embodiment has Figure 2 The structure shown.

[0091] like Figure 2 As shown, in pixel P according to the first embodiment, the conversion element D, the floating diffusion layer Cfd, and the differential amplifier circuit DA include the amplification transistor Tr. AMP Part of the feedback transistor Tr FB Clamping capacitor Ccl and reset transistor Tr RST It is disposed on the first substrate B1, which is the same substrate. For example... Figure 2As shown, in pixel P according to the first embodiment, the output stage of differential amplifier circuit DA (another part of differential amplifier circuit DA) is disposed on the second substrate B2. Therefore, pixel P according to the first embodiment has two inter-board coupling points J between the first substrate B1 and the second substrate B2.

[0092] The construction of pixel P according to the first embodiment is not limited to Figure 2 The example shown.

[0093] For example, multiple pixels P can share the floating diffusion layer Cfd, the differential amplifier circuit DA, and the feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0094] Figure 4 This is an illustrative diagram illustrating another example of the construction of pixel P according to the first embodiment, and shows that "two pixels P share a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr". FB Clamping capacitor Ccl and reset transistor Tr RST An exemplary construction of the "situation".

[0095] When the camera unit 102 has Figure 4 When constructing pixel P as shown, the transmission transistors Tr of each pixel P, including the shared floating diffusion layer Cfd, are controlled by the control signal TG. TG The conduction state is such that the charge corresponding to the conversion of the incident light through the conversion element D of each pixel P is transferred to the floating diffusion layer Cfd.

[0096] although Figure 4 An example is shown in which two pixels P share a floating diffusion layer Cfd, etc., but in the imaging unit 102, three or more pixels P can share a floating diffusion layer Cfd, etc. As an example, the imaging device 100 according to the first embodiment can have a structure in which four pixels P share a floating diffusion layer Cfd, etc., or a structure in which eight pixels P share a floating diffusion layer Cfd, etc. Even when three or more pixels P share a floating diffusion layer Cfd, etc., the transmission transistor Tr of each pixel P is controlled. TG The conduction state allows the charge corresponding to the conversion of incident light through the conversion element D in each pixel P to be transferred to the floating diffusion layer Cfd.

[0097] [2-2] Layout of pixel P according to the first embodiment

[0098] The following shows an exemplary layout of pixel P according to the first embodiment.

[0099] Figure 5 and Figure 6These are all schematic illustrations of exemplary layouts of pixel P according to the first embodiment. Figure 5 This shows that when pixel P has Figure 4 The diagram shows a schematic layout for the construction process. Figure 6 It is shown that the matrix arrangement has Figure 5 An exemplary pixel array of pixel P in the layout shown.

[0100] Figures 7A to 7J These are explanatory diagrams of exemplary layouts of pixel P according to the first embodiment, and respectively illustrate when pixel P has Figure 4 The example layout shown is an example of the construction process. Figures 7A to 7J The B shown is in Figures 7A to 7J Schematic diagrams of the II-line cross sections shown in A.

[0101] like Figures 7A to 7J As shown, pixel P according to the first embodiment can be implemented using a variety of wiring patterns. It should be understood that the layout of pixel P according to the first embodiment is not limited to... Figures 7A to 7J The example shown.

[0102] [3] Camera device according to the second embodiment

[0103] The imaging apparatus according to the second embodiment will now be described. The imaging apparatus according to the second embodiment has a structure (including variations) substantially similar to the imaging apparatus according to the first embodiment described above, wherein the structure of pixel P differs from that of pixel P in the imaging apparatus according to the first embodiment. In view of this, descriptions of the similarities between the imaging apparatus according to the second embodiment and the imaging apparatus according to the first embodiment will be omitted below, and an exemplary structure of pixel P according to the second embodiment will be described.

[0104] [3-1] Exemplary construction of pixel P according to the second embodiment

[0105] Figure 8 This is an explanatory diagram illustrating an exemplary construction of pixel P according to the second embodiment. Figure 8 An example is shown in which pixel P includes two substrates (including a first substrate B1 and a second substrate B2).

[0106] For example, according to the second embodiment, pixel P includes a conversion element D, a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0107] The difference between pixel P according to the second embodiment and pixel P according to the first embodiment is that the components disposed in the first substrate B1 and the second substrate B2 are respectively.

[0108] More specifically, such as Figure 8 As shown, in pixel P according to the second embodiment, the conversion element D, the floating diffusion layer Cfd, the clamping capacitor Ccl, and the reset transistor Tr RST It is disposed on the first substrate B1, which is the same substrate. For example... Figure 8 As shown, in pixel P according to the second embodiment, the differential amplifier circuit DA and the feedback transistor Tr FB The pixel P is disposed on the second substrate B2. Therefore, according to the second embodiment, the pixel P has an inter-board mating point J between the first substrate B1 and the second substrate B2, thus reducing the number of inter-board mating points J compared to the first embodiment.

[0109] like Figure 8 As shown, for example, the differential amplifier circuit DA is disposed on a different substrate than the first substrate B1 on which the conversion element D is disposed, thereby expanding the Si region on which the differential amplifier circuit DA is disposed. Therefore, it can be ensured that the size of the transistors included in the differential amplifier circuit DA is large enough that it is not limited by the size of the pixel P, and the degradation of characteristics such as P (precharge) phase change is prevented, thereby improving the analog circuit characteristics of the differential amplifier circuit DA.

[0110] The construction of pixel P according to the second embodiment is not limited to Figure 8 The example shown.

[0111] For example, similar to the first embodiment, multiple pixels P can share the floating diffusion layer Cfd, the differential amplifier circuit DA, and the feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0112] Figure 9 This is an illustrative diagram illustrating another example of the construction of pixel P according to the second embodiment, and shows that "two pixels P share a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr". FB Clamping capacitor Ccl and reset transistor Tr RST An exemplary construction of the "situation".

[0113] When the camera unit according to the second embodiment has Figure 9 When pixel P is constructed as shown, it has the same characteristics as the camera unit. Figure 4 The configuration of pixel P is the same as shown, with the transmission transistor Tr controlling each pixel P in the shared floating diffusion layer Cfd, etc. TG The conduction state is such that the charge corresponding to the conversion of the incident light through the conversion element D of each pixel P is transferred to the floating diffusion layer Cfd.

[0114] Similar to the camera unit 102 according to the first embodiment, although Figure 9 An example is shown in which two pixels P share a floating diffusion layer Cfd, etc., but in the camera unit according to the second embodiment, three or more pixels P may share a floating diffusion layer Cfd, etc.

[0115] [3-2] Layout of pixel P according to the second embodiment

[0116] An exemplary layout of pixel P according to the second embodiment is described below.

[0117] Figure 10 This is an explanatory diagram of the layout of pixel P according to the second embodiment, and shows when pixel P has Figure 9 The example layout shown is an example of the construction process. Figure 10 B shown is Figure 10 A schematic diagram of the section along line II shown in Figure A.

[0118] It should be understood that the layout of pixel P according to the second embodiment is not limited to... Figure 10 The example shown.

[0119] For example, with Figure 6 Similarly, the pixel array of the camera device according to the second embodiment has wherein... Figure 10 The layout shown is constructed by arranging the pixels P in a matrix.

[0120] [4] Camera device according to the third embodiment

[0121] The imaging apparatus according to the third embodiment will now be described. The imaging apparatus according to the third embodiment has a structure (including modifications) substantially similar to the imaging apparatus according to the first embodiment described above, wherein the structure of pixel P differs from the structure of pixel P in the imaging apparatus according to the first embodiment and the imaging apparatus according to the second embodiment. In view of this, descriptions of key aspects of the imaging apparatus according to the third embodiment that are similar to those in the imaging apparatus according to the first embodiment and the imaging apparatus according to the second embodiment will be omitted below, and an exemplary structure of pixel P according to the third embodiment will be described.

[0122] [4-1] Exemplary construction of pixel P according to the third embodiment

[0123] Figure 11 This is an explanatory diagram illustrating an exemplary construction of pixel P according to the third embodiment. Figure 11 An example is shown in which pixel P includes two substrates (including a first substrate B1 and a second substrate B2).

[0124] For example, according to the third embodiment, pixel P includes a conversion element D, a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0125] The difference between pixel P according to the third embodiment and pixel P according to the first embodiment and pixel P according to the second embodiment is that the components are disposed in each of the first substrate B1 and the second substrate B2.

[0126] More specifically, such as Figure 11 As shown, in pixel P according to the third embodiment, the conversion element D, the floating diffusion layer Cfd, and the reset transistor Tr RST It is disposed on the first substrate B1, which is the same substrate. For example... Figure 11 As shown, in pixel P according to the third embodiment, the differential amplifier circuit DA and the feedback transistor Tr are the same as those in pixel P according to the second embodiment. FB It is disposed on the second substrate B2. For example Figure 11 As shown, in pixel P according to the third embodiment, the clamping capacitor Ccl is an inter-line capacitance formed by bonding metal wiring that bonds substrates B1 and B2 together (an exemplary inter-line capacitance of wiring that bonds different substrates together). Examples of bonding metal wiring include metal for connecting pads.

[0127] Therefore, similar to pixel P according to the second embodiment, pixel P according to the third embodiment has an inter-board bonding point J between the first substrate B1 and the second substrate B2, thus reducing the number of inter-board bonding points J compared to the first embodiment.

[0128] Similar to pixel P according to the second embodiment, pixel P according to the third embodiment can have a large Si region in which a differential amplifier circuit DA is disposed, and thus the analog circuit characteristics of the differential amplifier circuit DA can be improved.

[0129] For example, according to the third embodiment, the pixel P can be formed using metal for connecting pads to form a capacitor, and can be coupled only to the insulating film, thus improving the connection yield.

[0130] The construction of pixel P according to the third embodiment is not limited to Figure 11 The example shown.

[0131] For example, similar to the first embodiment, multiple pixels P can share the floating diffusion layer Cfd, the differential amplifier circuit DA, and the feedback transistor Tr. FB Clamping capacitor Ccl and reset transistor Tr RST .

[0132] Figure 12 This is an illustrative diagram illustrating another example of the construction of pixel P according to the third embodiment, and shows that "two pixels P share a floating diffusion layer Cfd, a differential amplifier circuit DA, and a feedback transistor Tr". FB Clamping capacitor Ccl and reset transistor Tr RST An exemplary construction of the "situation".

[0133] When the camera unit according to the third embodiment has Figure 12 When pixel P is constructed as shown, it has the same characteristics as the camera unit. Figure 4 The configuration of pixel P is the same as shown, with the transmission transistor Tr controlling each pixel P in the shared floating diffusion layer Cfd, etc. TG The conduction state is such that the charge corresponding to the conversion of the incident light through the conversion element D of each pixel P is transferred to the floating diffusion layer Cfd.

[0134] although Figure 12 An example is shown in which two pixels P share a floating diffusion layer Cfd, etc., but like the camera unit 102 according to the first embodiment, in the camera unit according to the third embodiment, three or more pixels P may share a floating diffusion layer Cfd, etc.

[0135] [4-2] Layout of pixel P according to the third embodiment

[0136] An exemplary layout of pixel P according to the third embodiment is described below.

[0137] Figure 13 This is an explanatory diagram of the layout of pixel P according to the third embodiment, and shows when pixel P has Figure 12 The example layout shown is an example of the construction process. Figure 13 B shown is Figure 13 A schematic diagram of the section along line II shown in Figure A.

[0138] It should be understood that the layout of pixel P according to the third embodiment is not limited to... Figure 13 The example shown.

[0139] For example, the pixel array of the camera device according to the third embodiment has wherein... Figure 6 Same as Figure 13 The layout shown is constructed by arranging the pixels P in a matrix.

[0140] [5] Camera device according to another embodiment

[0141] The camera device according to this embodiment is not limited to the camera devices according to the first embodiment, the second embodiment and the third embodiment described above.

[0142] For example, in order to reduce signal interference between floating diffusion layers Cfd in the pixel array, the camera device according to this embodiment may also provide electrical shielding at the boundary portion between a pixel P that shares a floating diffusion layer Cfd and another pixel P that shares a floating diffusion layer Cfd adjacent to that one floating diffusion layer Cfd. For example, electrical shielding may be provided through a wiring layer.

[0143] Figure 14 This is an illustrative diagram of an exemplary layout of a pixel array of a camera device according to another embodiment, and shows an example in which clamping capacitor Ccl is formed using wiring within a substrate.

[0144] like Figure 14 As shown in A, electrical shielding is provided through a wiring layer at the boundary between a pixel P that shares a floating diffusion layer Cfd and another floating diffusion layer Cfd that is adjacent to that floating diffusion layer Cfd.

[0145] For example, the wiring included in the electrical shield (hereinafter referred to as "shielding wiring") is arranged to surround the entire boundary portion of the pixel or a portion of the boundary portion. Figure 14 B in the diagram illustrates an exemplary layout of the shielded wiring according to this embodiment. It should be understood that the layout of the shielded wiring is not limited to... Figure 14 Example B in the example.

[0146] For example, the wiring layer included in the electrical shield (hereinafter referred to as the "shielded wiring layer") includes the same metal wiring layer as the individual metal wiring layers included in the wiring of the substrate having a floating diffusion layer Cfd. The shielded wiring layer is connected to a terminal that provides a standard potential VSS.

[0147] although Figure 14 It shows from Figure 14 Starting from the bottom, the third and fourth wirings are used to form a clamping capacitor Ccl. Figure 14 The example shown is an inter-line capacitance, but in the case of using other wiring to form a clamping capacitance Ccl, it can also be like... Figure 14 That's how you set up shielded wiring.

[0148] Figure 15 This is an illustrative diagram of another example of the layout of the pixel array of a camera device according to another embodiment, and shows an example in which clamping capacitors Ccl are formed using the topmost wiring of each substrate.

[0149] Figure 15 The example shown is that the clamping capacitor Ccl is from... Figure 15 An example of the topmost pad layer formed as seen from the bottom. Figure 15 The example shown and Figure 14The difference between the examples shown is the location where the clamping capacitor Ccl is formed, and Figure 15 The example shown and Figure 14 The examples shown are identical except for the differences mentioned above.

[0150] For example, such as Figure 14 and Figure 15 As shown, in a camera device according to another embodiment, electrical shielding is provided by shielding wiring, thereby reducing signal interference between floating diffusion layers Cfd in the pixel array.

[0151] [6] Effects produced by the camera device according to this embodiment

[0152] For example, the camera device according to this embodiment produces the effects described below. It should be understood that the effects produced by the camera device according to this embodiment are not limited to the examples described below.

[0153] When initializing the potential of the floating diffusion layer Cfd, the reset potential of the floating diffusion layer Cfd can be VDD potential, therefore the transistor Tr included in the output stage of the differential amplifier circuit DA will not be affected. out2 The voltage drop in the process leads to a reduction in the dynamic range of the floating diffusion layer Cfd.

[0154] For example, when detecting various signals such as P-phase signals and D (data) phase signals (when detecting voltage signals obtained from the floating diffused layer Cfd), the feedback transistor Tr... FB When in the off state, the capacitance of the floating diffusion layer Cfd, which is similar to that of the floating diffusion layer according to the prior art, is sufficient, thus reducing the reduction in conversion efficiency in the floating diffusion layer Cfd.

[0155] As in the imaging device according to the second embodiment or the imaging device according to the third embodiment, the differential amplifier circuit DA is disposed on a different substrate than the substrate on which the conversion element D is disposed, thereby improving the circuit characteristics of the differential amplifier circuit DA. Because the differential amplifier circuit DA is disposed on a different substrate than the substrate on which the conversion element D is disposed, the number of board-to-board coupling points J can be further reduced.

[0156] (Application example of the camera device according to this embodiment)

[0157] As described in this embodiment, the imaging device is not limited to this mode. For example, this embodiment can be applied to various image sensors, such as "image sensors used in any moving body such as automobiles, electric vehicles, hybrid vehicles, motorcycles, bicycles, personal mobile devices, airplanes, drones, ships, robots, satellites, and measuring instruments," "industrial image sensors used in factories, distribution systems, etc.," "image sensors used in intelligent transportation systems (ITS)," and "crime prevention image sensors." For example, this embodiment can be applied to any device that includes an image sensor, such as a moving body that includes an image sensor.

[0158] The following describes an example of how the technology according to this disclosure is applied to a moving body.

[0159] Figure 16 This is a block diagram illustrating a schematic construction example of a vehicle control system that can be applied to an exemplary mobile body control system based on the technology disclosed herein.

[0160] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 16 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. As functional components of the integrated control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0161] The drive system control unit 12010 controls the operation of equipment related to the vehicle's drive system according to various computer programs. For example, the drive system control unit 12010 is used as a control device for the following devices: drive force generating devices such as internal combustion engines or drive motors for generating drive force for the vehicle; drive force transmission mechanisms for transmitting drive force to the wheels; steering mechanisms for adjusting the vehicle's steering angle; and braking devices for generating braking force for the vehicle.

[0162] The body system control unit 12020 controls the operation of various devices installed in the vehicle body according to various computer programs. For example, the body system control unit 12020 is used as a control device for keyless entry systems, smart key systems, power windows, or various lights such as headlights, reversing lights, brake lights, turn signals, and fog lights. In this case, radio waves emitted by a portable device that replaces a key or signals from various switches can be input to the body system control unit 12020. After receiving these radio waves or signal inputs, the body system control unit 12020 controls the vehicle's door locks, power windows, lights, etc.

[0163] The exterior information detection unit 12030 detects external information of the vehicle equipped with the vehicle control system 12000. For example, a camera unit 12031 is connected to the exterior information detection unit 12030. The exterior information detection unit 12030 causes the camera unit 12031 to capture images of the exterior of the vehicle and receives the captured images. Based on the received images, the exterior information detection unit 12030 can perform target detection processing for people, vehicles, obstacles, signs, symbols, etc. on the road, or perform distance detection processing.

[0164] The camera unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The camera unit 12031 can output an electrical signal as an image, and it can also output an electrical signal as distance measurement information. The light received by the camera unit 12031 can be visible light, or invisible light such as infrared light.

[0165] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detector 12041, which detects the driver's state, is connected to the in-vehicle information detection unit 12040. For example, the driver state detector 12041 includes a camera for capturing images of the driver. Based on the detection information input from the driver state detector 12041, the in-vehicle information detection unit 12040 can calculate the driver's level of fatigue or concentration, or determine whether the driver has fallen asleep.

[0166] The microcomputer 12051 can calculate target control values ​​for the drive force generating device, steering mechanism, or braking device based on information obtained from the external vehicle information detection unit 12030 or the internal vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control designed to implement advanced driver assistance system (ADAS) functions, including collision avoidance or shock absorption, distance-based following, speed maintenance, collision warning, and lane departure warning.

[0167] The microcomputer 12051 controls the drive force generating device, steering mechanism or braking device based on information about the vehicle's surroundings obtained by the external information detection unit 12030 or the internal information detection unit 12040, thereby enabling cooperative control such as autonomous driving that is designed to drive autonomously without relying on the driver's operation.

[0168] The microcomputer 12051 can output control commands to the body system control unit 12020 based on information about the exterior of the vehicle obtained by the exterior information detection unit 12030. For example, the microcomputer 12051 can perform cooperative control aimed at glare reduction, which includes controlling the headlights according to the position of the preceding vehicle or a vehicle in the oncoming lane detected by the exterior information detection unit 12030, and switching the high beam to the low beam.

[0169] The sound / image output unit 12052 transmits an output signal of at least one of sound or image to an output device capable of providing visual or auditory information to passengers of the vehicle or to an external part of the vehicle. Figure 16 The examples illustrate audio speaker 12061, display unit 12062, and device panel 12063 as output devices. For example, display unit 12062 may include at least one of an in-vehicle display or a head-up display.

[0170] Figure 17 This is a diagram of an exemplary mounting location for the camera unit 12031.

[0171] exist Figure 17 In the vehicle 12100, there are camera units 12101, 12102, 12103, 12104 and 12105, which serve as camera units 12031.

[0172] For example, camera units 12101, 12102, 12103, 12104, and 12105 are installed at locations on the vehicle 12100, such as the front nose, rearview mirrors, rear bumper, rear door, and the upper part of the windshield inside the passenger compartment. Camera unit 12101 at the front nose and camera unit 12105 at the upper part of the windshield inside the passenger compartment primarily acquire images of the front of the vehicle 12100. Camera units 12102 and 12103 at the rearview mirrors primarily acquire images of the sides of the vehicle 12100. Camera unit 12104 at the rear bumper or rear door primarily acquires images of the rear of the vehicle 12100. The front images acquired by camera units 12101 and 12105 are mainly used to detect vehicles or pedestrians, obstacles, traffic signals, traffic signs, and driving lanes ahead.

[0173] Figure 17Exemplary camera ranges of camera units 12101 to 12104 are shown. Camera range 12111 represents the camera range of camera unit 12101 located at the front nose; camera ranges 12112 and 12113 represent the camera ranges of camera units 12102 and 12103 located at each rearview mirror, respectively; and camera range 12114 represents the camera range of camera unit 12104 located at the rear bumper or rear door. For example, by overlaying multiple image data captured by camera units 12101 to 12104, a top-down view of vehicle 12100 viewed from above is obtained.

[0174] At least one of the camera units 12101 to 12104 may have the function of obtaining distance information. For example, at least one of the camera units 12101 to 12104 may be a stereo camera including a plurality of camera elements, or a camera element having pixels for phase difference detection.

[0175] For example, based on distance information obtained from camera units 12101 to 12104, microcomputer 12051 determines the distance to each three-dimensional object within the camera range 12111 to 12114 and the time change of that distance (relative speed to vehicle 12100). This allows it to specifically extract the closest three-dimensional object traveling in the same direction as vehicle 12100 at a predetermined speed (e.g., above 0 km / h) as the preceding vehicle. Furthermore, microcomputer 12051 can pre-set a following distance to maintain with the preceding vehicle to execute automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), etc. Therefore, cooperative control aimed at autonomous driving without driver intervention can be performed.

[0176] For example, microcomputer 12051 can extract multiple sets of stereoscopic object data based on distance information obtained from camera units 12101 to 12104, and classify them into motorcycles, ordinary vehicles, large vehicles, pedestrians, and other stereoscopic objects such as utility poles, and use them for automatic obstacle avoidance. For example, regarding obstacles around vehicle 12100, microcomputer 12051 distinguishes between obstacles that are visually identifiable by the driver of vehicle 12100 and obstacles that are difficult for the driver of vehicle 12100 to visually identify. Microcomputer 12051 determines a collision risk that represents the degree of risk of colliding with each obstacle, and if the collision risk is above a set value and there is a possibility of a collision, it outputs a warning to the driver via audio speaker 12061 or display unit 12062, or executes forced deceleration or evasive steering via drive system control unit 12010, thereby performing collision avoidance driving assistance.

[0177] At least one of the camera units 12101 to 12104 can be an infrared camera that detects infrared light. For example, microcomputer 12051 determines whether any pedestrians are present in the images captured by camera units 12101 to 12104, thereby identifying the pedestrians. This pedestrian identification process is performed, for example, by extracting feature points from the images captured by camera units 12101 to 12104 (which are infrared cameras), performing pattern matching processing on a series of feature points representing the outline of an object, thereby determining whether the object is a pedestrian. When microcomputer 12051 determines that any pedestrians are present in the images captured by camera units 12101 to 12104 and identifies the pedestrian, sound / image output unit 12052 controls display unit 12062 to overlay a square outline for emphasis on the identified pedestrian. Sound / image output unit 12052 can also control display unit 12062 to display icons or similar indicators of pedestrians at desired locations.

[0178] An exemplary vehicle control system has been described when the technology according to this embodiment is applied to a moving body. For example, the technology according to this embodiment can be applied to camera unit 12031 in a vehicle control system. It should be understood that the components applied by the technology according to this embodiment are not limited to camera unit 12031 in a vehicle control system.

[0179] Preferred embodiments of the present disclosure have been described with reference to the accompanying drawings, but the scope of the present disclosure is not limited to these examples. It is obvious that those skilled in the art will conceive of various modifications or alterations within the scope of the technical concept set forth in the claims, and it should be understood that they naturally also fall within the scope of the present disclosure.

[0180] The effects described in this specification are illustrative and exemplary only, and not restrictive. In other words, based on the description in this specification, it will be apparent to those skilled in the art that the technology of this disclosure can produce other effects in conjunction with or instead of the aforementioned effects.

[0181] The following structures also fall within the technical scope of this disclosure. (1)

[0183] A camera device includes a camera unit having multiple pixels.

[0184] Each of the pixels has:

[0185] A conversion element that converts incident light into photoelectrons;

[0186] A floating diffusion layer is electrically connected to the conversion element and converts the photoelectrons into voltage signals;

[0187] A differential amplifier circuit, electrically connected to the floating diffusion layer, includes an amplifying transistor that receives the potential of the floating diffusion layer and amplifies the potential of the floating diffusion layer;

[0188] Feedback transistor, electrically connected to the amplifying transistor and initializing the differential amplifier.

[0189] Circuit;

[0190] A clamping capacitor is connected in series between the floating diffusion layer and the amplifying transistor;

[0191] and

[0192] A reset transistor is connected in parallel between the floating diffusion layer and the clamping capacitor, and initializes the potential of the floating diffusion layer. (2)

[0194] According to the camera device described in (1), the pixels share the floating diffusion layer, the differential amplifier circuit, the feedback transistor, the clamping capacitor, and the reset transistor. (3)

[0196] According to the camera device described in (1) or (2), wherein,

[0197] The camera unit includes multiple laminated substrates, and

[0198] At least the switching element, the floating diffusion layer, and the reset transistor are disposed on the same substrate. (4)

[0200] According to the imaging device described in (3), the conversion element, the floating diffusion layer, the portion of the differential amplifier circuit including the amplifying transistor, the feedback transistor, the clamping capacitor, and the reset transistor are disposed on the same substrate. (5)

[0202] According to the imaging device described in (3), the conversion element, the floating diffusion layer, the clamping capacitor and the reset transistor are disposed on the same substrate. (6)

[0204] According to the camera device described in (3), wherein,

[0205] The switching element, the floating diffusion layer, and the reset transistor are disposed on the same substrate, and

[0206] The clamping capacitor is the inter-line capacitance of the wiring that bonds different substrates together. (7)

[0208] The camera device according to any one of (1) to (6), wherein,

[0209] When the potential of the floating diffusion layer is initialized, the feedback transistor is in the ON state, and the terminal of the amplifying transistor electrically connected to the floating diffusion layer is fixed at the initial potential of the differential amplifier circuit.

[0210] When the voltage signal obtained from the floating diffusion layer is detected, the feedback transistor is in the off state, and the terminals of the amplifying transistor are electrically floating.

[0211] List of reference numerals

[0212] 100 camera devices

[0213] 102 camera units

[0214] 104 drives

[0215] Cfd floating diffusion layer

[0216] Ccl clamping capacitor

[0217] D conversion element

[0218] DA differential amplifier circuit

[0219] P pixel

[0220] Tr AMP Amplifying transistors

[0221] Tr FB Feedback transistor

[0222] Tr RST Reset transistor

Claims

1. A camera device, comprising: A first substrate, the first substrate comprising: Multiple pixels, said multiple pixels including a first pixel, the first pixel including a first conversion element, and A first portion of the differential amplifier circuit is connected to the first conversion element via a transfer transistor, a floating diffuser, and a capacitor as a clamping capacitor; and A second substrate, laminated onto the first substrate, the second substrate comprising: The second part of the differential amplifier circuit, wherein the first part of the differential amplifier circuit is connected to the second part of the differential amplifier circuit; The first part and the second part of the differential amplifier circuit are electrically connected by a metal junction. The capacitor is connected in series between the floating diffuser and the first input of the differential amplifier circuit. A feedback transistor is connected to the first input of the first portion of the differential amplifier circuit and configured to initialize the differential amplifier circuit. A reset transistor is connected in parallel between the floating diffuser and the capacitor, and is configured to initialize the potential of the floating diffuser.

2. The camera device according to claim 1, wherein, The first substrate and the second substrate are electrically connected via connecting pads.

3. The camera device according to claim 2, wherein, The first conversion element and the second conversion element of the second pixel among the plurality of pixels share the floating diffusion section.

4. The camera device according to claim 3, wherein, The first part of the differential amplifier circuit includes a first input and a second input, wherein the second input receives a reference signal.

5. The camera device according to claim 1, wherein, The first pixel and the second pixel among the plurality of pixels share the floating diffuser, the differential amplifier circuit, the feedback transistor, the capacitor, and the reset transistor.

6. The camera device according to claim 1, wherein, The feedback transistor is located on the second substrate.

7. The camera device according to claim 1, wherein, The feedback transistor is located on the second substrate, and the reset transistor is located on the first substrate.

8. The camera device according to claim 7, wherein, The capacitor is located on the first substrate.

9. The camera device according to claim 1, wherein, When the potential of the floating diffuser is initialized, the feedback transistor is in the ON state, and the terminals of the differential amplifier circuit connected to the floating diffuser are fixed at the initial potential. When the voltage signal obtained by the floating diffusion section is detected, the feedback transistor is in the off state, and the terminals of the differential amplifier circuit are electrically floating.

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