Imaging device and electronic equipment

Abstract

To provide an advantageous technique for reducing image noise in an imaging apparatus and electronic equipment.SOLUTION: An imaging apparatus includes: an imaging device in which a plurality of photoelectric conversion elements is arranged in an array; a plurality of wiring components in which the imaging device is mounted and power source wiring is provided; a plurality of pieces of connection wiring that connects the power source wiring and the imaging device each other; at least two power supply sources connected to the power source wiring; and at least one power supply source connected to the power source wiring. The two power supply sources and the one power supply source supply power to the imaging device via the power source wiring and the plurality of connection wiring. At a horizontal synchronization frequency of the imaging device, the two power supply sources have lower impedances than the one power supply source, and at least one connection wiring of the plurality of connection wiring is connected to a wiring path connecting the two power supply sources in the power source wiring.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Imaging devices such as digital video cameras and digital still cameras include an imaging device having an image sensor. In recent years, the ISO (International Organization for Standardization) sensitivity in image sensors has been improving. As a result, even when shooting in a scene with little light such as at night, a clearer image is generated. Also, with the increase in the continuous shooting speed, it has become possible to shoot faster moving subjects.

[0003] However, with the improvement of the ISO sensitivity in image sensors, the sensitivity to weak ambient magnetic field noise, which was not a problem conventionally, has also increased. As a result, the problem that the image sensor is affected by magnetic field noise and the image is distorted has become apparent. Also, the power consumption current has increased due to high-speed operation. Along with this, a magnetic field is radiated from the power supply wiring pattern of the imaging device, and a problem has occurred in which noise is generated in a part of the captured image due to the influence of this magnetic field.

[0004] Patent Document 1 discloses a technique for reducing the influence of at least one of a magnetic field and an electric field generated by a current supplied from a power source to an electronic component on an electronic unit or its exterior.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The technology described in Patent Document 1 does not adequately address the reduction of image noise. This invention has been made in view of the above problems, and aims to provide a technology that is advantageous for reducing image noise in imaging devices and electronic equipment. [Means for solving the problem]

[0007] According to one aspect of the present invention, an imaging device is provided comprising: an imaging device on which a plurality of photoelectric conversion elements are arranged in an array; a wiring component on which the imaging device is mounted and which is provided with power supply wiring; a plurality of connecting wires that connect the power supply wiring and the imaging device to each other; at least two power supply sources connected to the power supply wiring; and at least one power supply source connected to the power supply wiring, wherein the two power supply sources and the one power supply source supply power to the imaging device via the power supply wiring and the plurality of connecting wires; the two power supply sources have a lower impedance than the one power supply source at the horizontal synchronization frequency of the imaging device; and at least one of the plurality of connecting wires is connected to the wiring path connecting the two power supply sources in the power supply wiring. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technology that is advantageous for reducing image noise in imaging devices and electronic devices. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram showing an imaging device, which is an example of an electronic device according to the first embodiment. [Figure 2] This is an explanatory diagram showing an imaging device according to the first embodiment. [Figure 3] This is an explanatory diagram showing the circuit block of the imaging device according to the first embodiment. [Figure 4] This is an explanatory diagram showing the arrangement of the first power supply source according to the first embodiment. [Figure 5]This is an explanatory diagram showing the arrangement of the first power supply source, which is a comparative example. [Figure 6] This is an explanatory diagram comparing the amount of current flowing through the power supply wiring in the first embodiment and the comparative example. [Figure 7] This is an explanatory diagram showing the arrangement of the first power supply source according to the second embodiment. [Figure 8] This is an explanatory diagram showing the arrangement of the first power supply source according to the third embodiment. [Figure 9] This is an explanatory diagram showing the arrangement of the first power supply source according to the fourth embodiment. [Figure 10] This is an explanatory diagram showing the resistance ratio and current magnitude of the first power supply source according to the fourth embodiment. [Figure 11] This is an explanatory diagram showing the arrangement of the first power supply source according to the fifth embodiment. [Figure 12] This is an explanatory diagram showing the arrangement of the first power supply source according to the sixth embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. [First Embodiment] Figure 1 is an explanatory diagram showing an electronic device 100 according to the first embodiment. The electronic device 100 is a digital camera, such as a digital still camera or a digital video camera, and in the example of Figure 1, it is a digital single-lens reflex camera. The electronic device 100 comprises a main body 101 and an interchangeable lens 102, which is a lens device that can be attached to the main body 101. The electronic device 100 may also be an information terminal with a camera, such as a smartphone or a personal computer.

[0011] The main unit 101 includes an image processing board 103 on which image processing semiconductors and the like are mounted, and an imaging device 104 capable of capturing visible light incident from the interchangeable lens 102. The main unit 101 also includes an image stabilization unit 112 and a display 113.

[0012] The image processing board 103 is connected to the imaging device 104 via the connector 105 and the flexible cable 106. The flexible cable 106 transmits signals such as power supply from the image processing board 103 to the imaging device 104 and image data output from the imaging device 104 to the image processing board 103. The image processing board 103 functions as a processing device that processes signals such as image data output from the imaging device 104. The shake correction unit 112 is a driving device that moves the imaging device 104, and moves the imaging device 104 during imaging to reduce or prevent deterioration of image quality due to camera shake. The display 113 is a display device that displays an image based on the image data processed by the imaging device 104. Inside the main body 101, a battery (not shown) is arranged, and power is supplied from the battery to the image processing board 103, the imaging device 104, the interchangeable lens 102, the shake correction unit 112, and the display 113.

[0013] FIG. 2 is a perspective view of the imaging device 104 according to the first embodiment. The imaging device 104 includes a printed wiring board 107, an imaging device 108 having a photoelectric conversion element, a connection wiring 109, a frame body 110, and a cover glass 111.

[0014] The printed wiring board 107 is connected to the imaging device 108 having a photoelectric conversion element via a plurality of connection wirings 109. The printed wiring board 107 is a wiring component that supplies power and control signals to the imaging device 108 and transfers digital data after photoelectric conversion from the imaging device. The connection wiring 109 is not particularly limited, but is generally a bonding wire made of gold, aluminum, or the like. The connection wiring 109 may be a solder bump. Instead of the printed wiring board 107, a wiring component such as a ceramic package can be used. The number of the connection wirings 109 is not particularly limited, but is, for example, 12 or more.

[0015] The imaging device 108 is mounted on the printed wiring board 107. The imaging device 108 may be mounted in a state of being housed in a package. The imaging device 108 includes a pixel chip 108a having a photodiode and the like, which will be described later, and a circuit chip 108b having a preamplifier and a comparator, which will be described later, and has a stacked structure in which both are electrically connected. For example, the imaging device 108 is a stacked image sensor including a first semiconductor layer having a plurality of photoelectric conversion elements, a second semiconductor layer stacked on the first semiconductor layer and having an integrated circuit, and a wiring layer positioned between the first semiconductor layer and the second semiconductor layer. In the present embodiment, the imaging device 108 is not limited to this, and may be an imaging device in which the pixel chip 108a and the circuit chip 108b are formed on the same semiconductor.

[0016] In addition, the imaging device 108 is sealed with a frame body 110 molded with resin or the like and adhered to the printed wiring board 107 with an adhesive or the like, and a cover glass 111 adhered to the opposite side of the frame body 110 from the printed wiring board 107 with an adhesive or the like.

[0017] The imaging device 108 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge-Coupled Device) image sensor. The area of the imaging region of the imaging device 108 is not particularly limited. For example, it is 200 mm 2 or more (equal to or larger than the size of Micro Four Thirds), 300 mm 2 or more (equal to or larger than the size of APS-C), 800 mm 2 or more (equal to or larger than the full-size).

[0018] Figure 3 is a circuit block diagram showing the configuration of the imaging device 108 according to the first embodiment. The imaging device 108 has a structure in which a plurality of pixels 300 are arranged in a grid. Note that the plurality of pixels 300 can be arranged in an array. Each pixel 300 consists of a photodiode 301, which is an example of a light receiving unit that performs photoelectric conversion, a floating diffusion (FD) capacitive element 302 that stores charge, and a transistor 303 that controls charge transfer. Analog power supply 304 and analog ground 305 are connected to each of these pixels 300 via connection wiring 109 from a printed circuit board 107. These connection wiring 109 act as a path for supplying current related to the imaging operation and for the return current.

[0019] The imaging device 108 also includes multiple drivers 306, row selection lines 307, readout lines 308, multiple readout circuits 309, and a digital circuit 310. The multiple drivers 306 select pixels 300 from which photoelectrically converted charge is extracted via the row selection lines 307. The multiple readout circuits 309 include preamplifiers that amplify the signal that has been photoelectrically converted at the pixels 300 and read out via the readout lines 308, and comparators for converting it into a digital signal. The digital circuit 310 digitally processes the readout signal and transmits the image signal from the digital signal output 311 to the image processing board 103. Differential signals are generally used for transmitting image signals. The digital circuit 310 is connected to a digital power supply 312 and a digital ground 313 via connection wiring 109 from the printed circuit board 107. These connection wirings 109 serve as the supply and return current paths for the digital signal processing.

[0020] Figure 4 is a schematic diagram showing the power supply wiring 400 of the imaging apparatus 104 and the power supply source that supplies power to the imaging device 108 according to the first embodiment. Figure 4(a) is a perspective view, Figure 4(b) is a top view, and Figure 4(c) is a cross-sectional view showing a cross section along the line aa' in Figure 4(a).

[0021] As shown in Figure 4, the imaging device 104 includes a power supply wiring 400, a ground wiring 401, a first power supply source 402a and 402b, a second power supply source 403, and a plurality of connection wirings 109a to 109x as connection wiring 109. In Figure 4(b) and the later-described Figures 5(b), 7(a), 8(a), 9(a), 11(a), and 12(a), for clarity, the positional relationships between components in the direction perpendicular to the surface of the printed circuit board 107 are appropriately ignored. Also, in Figure 4(c) and the later-described Figure 5(c), for clarity, the positions of components in the direction parallel to the surface of the printed circuit board 107 are appropriately changed.

[0022] The power supply wiring 400 is formed on a conductive material, such as copper, on the printed circuit board 107. The power supply wiring 400 is formed, for example, on the peripheral edge of the printed circuit board 107. Specifically, the power supply wiring 400 is formed to have an open loop shape along each of the four sides of the quadrilateral imaging device 108. Multiple connection wires 109a to 109x connect the power supply wiring 400 and the imaging device 108 to each other.

[0023] The power supply wiring 400 functions as a path for supplying power to the imaging device 108 via a plurality of connection wirings 109a to 109x. The plurality of connection wirings 109a to 109x connecting the power supply wiring 400 and the imaging device 108 are arranged at predetermined intervals along the power supply wiring 400, which for example has an open loop shape. The power supply wiring 400 may consist of only one layer of the printed circuit board 107, or it may consist of multiple layers, as shown in Figure 4(c), which are connected by vias between the layers.

[0024] From the viewpoint of reducing the influence of the imaging device 108 on imaging, it is preferable that the power supply wiring 400 is formed so as not to overlap with 90% or more of the imaging area of ​​the imaging device 108.

[0025] The ground wire 401 is formed on the printed circuit board 107 using a conductor, such as copper. The ground wire 401 functions as a return path for the current supplied from the power supply wire 400 to the imaging device 108, and, like the power supply wire 400, is connected to the imaging device 108 via a plurality of connection wires 109a to 109x.

[0026] Multiple first power sources 402a and 402b supply power to the imaging device 108 via power supply wiring 400 and multiple connection wirings 109a to 109x. The first power sources 402a and 402b are, for example, power supply ICs mounted on a printed circuit board 107, power supply ICs mounted on an image processing board 103 via a connector 105, and capacitors. The capacitors serving as the first power sources 402a and 402b are, for example, capacitors with the same standard capacitance value. Note that capacitance value is expressed as a standard number ± tolerance, and the standard capacitance value is this standard number. The capacitance values ​​of the capacitors serving as the first power sources 402a and 402b only need to have the same standard number, and may differ within the tolerance range. If the standard capacitance values ​​of two capacitors are the same, then the capacitance values ​​of these two capacitors can be said to be approximately the same. The power supply ICs are, for example, linear regulators and switching regulators, such as LDO (Low Dropout) regulators and DC / DC converters. The first power sources 402a and 402b are, for example, a combination of an integrated circuit and a capacitor, where one is an integrated circuit and the other is a capacitor. Also, one of the first power sources 402a and 402b may be a regulator. The number of first power sources is not limited to two; for example, for 12 or more connection wires 109, there may be six or more.

[0027] Similarly, at least one second power source 403 is located on the printed circuit board 107 or image processing board 103 to supply power to the imaging device 108 via the power supply wiring 400 and a plurality of connection wirings 109a to 109x. The second power source 403 is, for example, a relatively small-capacity ceramic capacitor.

[0028] Figure 4(b) shows a case where two first power sources 402a and 402b and six second power sources 403 are mounted on the printed circuit board 107, but it is not limited to this. The printed circuit board 107 only needs to have at least two first power sources and at least one second power source mounted on it.

[0029] The difference between the first power sources 402a and 402b and the second power source 403 lies in their impedance. The frequency of the current flowing through the power wiring 400 is roughly synchronized with the operating frequency of the imaging device 108, and is generally the horizontal synchronization frequency (approximately 20kHz to 200kHz). The frequency of the current flowing through the power wiring 400 varies depending on the shooting mode. The current component in this frequency band is a factor in generating image noise. The second power source 403 is generally provided on the printed circuit board 107 to supply power of the order of MHz or higher to the imaging device 108, and multiple second power sources are arranged close to the imaging device 108, i.e., near the connection wiring 109. In the horizontal synchronization frequency band that is the issue here, the impedance of the second power source 403 is higher than that of the first power sources 402a and 402b, so the second power source 403 cannot be an effective power source in this frequency band. On the other hand, the first power sources 402a and 402b are selected to have lower impedances than the second power source 403 in the horizontal sync frequency band. Therefore, in the horizontal sync frequency band, only the multiple first power sources 402a and 402b can supply power to the imaging device 108. Specifically, the first power sources 402a and 402b can have an impedance of less than 10[Ω] at the above horizontal sync frequency. The impedance of the first power sources 402a and 402b at the horizontal sync frequency may be 5[Ω] or less or 1[Ω] or less, or 1[mΩ] or more or 5[mΩ] or more. Furthermore, it is preferable that the impedance ratio of the multiple first power sources 402a and 402b is within 5 times.

[0030] The first power sources 402a and 402b and the second power source 403 described above are not composed solely of resistive components, but each includes at least one of capacitive and inductive components. Therefore, the impedances of the first power sources 402a and 402b and the second power source 403 each have frequency dependence.

[0031] The mechanism by which image noise is generated is described below. When the imaging device 108 starts taking images, a current with a period corresponding to the horizontal synchronization frequency flows through the connection wires 109a to 109x to supply power to the imaging device 108. At this time, the sum of the currents that flowed through each connection wire 109a to 109x flows through the power supply wire 400. When current flows through the power supply wire 400, a radiated magnetic field is generated around it according to the right-hand rule, and this radiated magnetic field links with the closed circuits formed by the wiring inside the imaging device 108 (readout wire 308, row selection wire 307, etc.), generating an induced electromotive force. This induced electromotive force is superimposed on the desired signal voltage converted by photoelectricity, and when the readout circuit 309 detects this signal, image noise is generated. The amount of image noise generated at this time increases as the strength of the generated magnetic field increases. Therefore, in Figure 4, it can be seen that the image noise is locally increased near the power supply wire 400.

[0032] Next, following the mechanism for generating image noise described above, the image noise reduction effect in the first embodiment will be explained by comparing Figure 4, which is the first embodiment, with Figure 5, which is a comparative example. In the first embodiment, there are 24 connection wires 109a to 109x and two first power supply sources 402a and 402b.

[0033] First, Figure 5, which is a comparative example, will be explained. Components with the same configuration as in Figure 4 are denoted by the same reference numerals. Furthermore, for the sake of simplicity, the current supplied to the imaging device 108 from each of the multiple connection wires 109a to 109x is assumed to be equal in Io[A]. Additionally, the impedances of the first power sources 402a and 402b at their horizontal synchronization frequencies are assumed to be equal.

[0034] In Figure 5, the first power sources 402a and 402b are both mounted at approximately the same position at the end of the power wiring 400. In this case, all the current supplied to the connecting wires 109a to 109x flows through the first power sources 402a and 402b. For example, the power wiring 400 between connecting wire 109w and connecting wire 109x has a current Io[A] flowing through it that is supplied to connecting wire 109x. Next, between connecting wire 109v and connecting wire 109w, a current of 2Io[A] flows, which is the sum of the currents supplied to connecting wire 109w and connecting wire 109x. Repeating this process, the power wiring 400 between the first power sources 402a and 402b and connecting wire 109a has a current of 24Io[A] flowing through it, which is the current for 24 connecting wires from 109a to 109x. Therefore, a magnetic field corresponding to this amount of current is generated, and image noise corresponding to the strength of this magnetic field is generated.

[0035] Next, Figure 4, which represents the first embodiment, will be described. The difference between Figure 4, which represents the first embodiment, and Figure 5, which represents a comparative example, is that in Figure 4, one connecting wire 109a is placed between the first power supply source 402a and the first power supply source 402b. That is, in this embodiment, one connecting wire 109a is connected to the wiring path connecting the first power supply source 402a and the first power supply source 402b in the power supply wiring 400. By distributing the current flowing through the power supply wiring 400, the magnetic field generated by the load current can be reduced. Note that it is sufficient for at least one connecting wire 109 to be connected to the wiring path connecting the first power supply source 402a and the first power supply source 402b in the power supply wiring 400. In the following description, when Z is placed between X and Y, it means that Z is placed in the path from X to Y (or from Y to Z), and in this case, the path is not limited to a straight path connecting X and Y, but may be a wiring path (electrical path) connecting X and Y.

[0036] In Figure 4, the current supplied to each connection wiring 109a to 109x is 0.5Io[A] from each of the first power sources 402a and 402b, since their impedances are the same. The sum of these currents flows through the power wiring 400, and this current can be determined as follows using the superposition principle in electrical circuits.

[0037] A current of 24 × 0.5Io[A] = 12Io[A] flows through the power supply wiring 400 between the first power supply source 402a and the connecting wiring 109a.

[0038] Next, consider the current flowing between the first power source 402b and the connecting wire 109a. Between them, the first power source 402a supplies a current of 23 × 0.5Io[A] = 11.5Io[A] to the connecting wires 109b to 109x. On the other hand, the first power source 402b also supplies a current of 1 × 0.5Io = 0.5Io[A] to the connecting wire 109a, but this is in the opposite direction to the 11.5Io[A] supplied by the first power source 402a. In conclusion, the total current flowing between the first power source 402b and the connecting wire 109a is (11.5 - 0.5)Io[A] = 11Io[A].

[0039] Next, we consider the current flowing between the first power source 402b and the connecting wire 109b in the same way as before. Between them, the first power source 402a supplies a current of 23 × 0.5Io[A] = 11.5Io[A] to the connecting wires 109b to 109x. Meanwhile, the first power source 402b supplies a current of 23 × 0.5Io = 11.5Io[A] to the connecting wires 109b to 109x. Since the direction of these currents is the same, the total current flowing between the first power source 402b and the connecting wire 109b is (11.5 + 11.5)Io[A] = 23Io[A].

[0040] From this point onward, the current flowing between each connecting wire is calculated in the same way as the current flowing between the first power source 402b and the connecting wire 109b.

[0041] Figure 6 plots the magnitude of the current flowing through each part of the power supply wiring 400, as described in the first embodiment in Figure 4 and the comparative example in Figure 5. The letters on the horizontal axis are only the subscripts for the connection wirings 109a to 109x in Figures 4 and 5. The values ​​on the vertical axis are the current values ​​divided by Io. As can be seen, the current, which was a maximum of 24Io[A] in the comparative example, is reduced to 23Io[A] in the first embodiment. Therefore, it is possible to reduce the amount of image noise caused by the magnetic field resulting from this current.

[0042] Thus, according to this embodiment, the imaging device 104 can reduce image noise caused by the radiated magnetic field generated from the power supply wiring pattern 400.

[0043] [Second Embodiment] Figure 7(a) is a top view showing the power supply wiring 400 and power supply sources that supply power to the imaging device 108 of the imaging apparatus according to the second embodiment. In Figure 7(a), the first power supply source 402a is placed between the connecting wiring 109f and 109g, and the first power supply source 402b is placed between the connecting wiring 109r and 109s. In this case as well, the same discussion as in the first embodiment will be carried out.

[0044] Consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109f. The current supplied from the first power source 402a is half the current of the six connecting wirings from 109a to 109f, which is 6 × 0.5Io = 3Io [A]. Similarly, the current supplied from the first power source 402b is also half the current of the six connecting wirings from 109a to 109f, which is 6 × 0.5Io = 3 [A]. In total, the sum of these currents, 6Io [A], flows through the power supply wiring 400 between the first power source 402a and the connecting wiring 109f.

[0045] A current of 6Io[A] flows through the power supply wiring 400 between the first power source 402b and the connecting wiring 109s, according to the same reasoning.

[0046] Next, let's consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109g. First, a current of 9Io[A] flows through this wiring from the first power source 402a, which is half the current from the 18 connecting wirings from 109g to 109x. Next, a current of 3Io[A] flows through this wiring from the first power source 402b, which is half the current from the 6 connecting wirings from 109a to 109f. Since these currents are in opposite directions, the total current flowing through the power supply wiring 400 between the first power source 402a and the connecting wiring 109g is (9-3)Io=6Io[A]. Similarly, a current of 6Io[A] also flows through the power supply wiring 400 between the first power source 402b and the connecting wiring 109r.

[0047] Figure 7(b) plots the magnitude of the current flowing through each part of the power supply wiring 400, as described in the second embodiment in Figure 7(a) and the comparative example in Figure 5. The letters on the horizontal axis and the numerical values ​​on the vertical axis in Figure 7(b) are the same as those in Figure 6. This shows that the current flowing through the power supply wiring 400 is a maximum of 24Io[A] in the comparative example, while in the second embodiment it is a maximum of 6Io[A], demonstrating a significantly higher current reduction effect. In this case, it is desirable to have half the total number of connecting wires between the first power supply source 402a and the first power supply source 402b.

[0048] [Third Embodiment] Figure 8(a) is a top view showing the power supply wiring 400 and power sources supplying power to the imaging device 108 of the imaging apparatus according to the third embodiment. Figure 8(a) has three first power sources. In Figure 8(a), the first power source 402a is placed between connecting wiring 109d and connecting wiring 109e, the first power source 402b is placed between connecting wiring 109l and connecting wiring 109m, and the first power source 402c is placed between connecting wiring 109t and connecting wiring 109u. In this embodiment as well, it is assumed that the impedances of the first power sources 402a, 402b, and 402c are equivalent. Therefore, each first power source 402 supplies 1 / 3 of the current Io flowing through each connecting wiring 109.

[0049] First, let's consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109d. The current supplied from the first power source 402a in this section is 1 / 3 of the current supplied by the four connecting wirings from 109a to 109d, which is 4 × 1 / 3Io = 4 / 3Io[A]. Similarly, the current supplied from the first power sources 402b and 402c is also 4 / 3Io[A], and as a result, the sum of these currents, (4 / 3 + 4 / 3 + 4 / 3)Io = 4[IoA], flows through the power supply wiring 400 between the first power source 402a and the connecting wiring 109d.

[0050] Next, consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109e. First, the current supplied from the first power source 402a in this section is 20 / 3Io[A], which is 1 / 3 of the current supplied by the 20 connecting wirings from 109e to 109x. Also, the current supplied from the first power source 402b in this section is 4 / 3Io[A], which is 1 / 3 of the current supplied by the 4 connecting wirings from 109a to 109d, and this is in the opposite direction to the current supplied from the first power source 402a. Furthermore, the current supplied from the first power source 402c is also 4 / 3Io[A], which is 1 / 3 of the current supplied by the 4 connecting wirings from 109a to 109d, and this is in the opposite direction to the current supplied from the first power source 402a. Therefore, a current of (20 / 3 - 4 / 3 - 4 / 3)Io = 4Io [A] flows through the power supply wiring 400 between the first power supply source 402a and the connecting wiring 109e.

[0051] The current distribution obtained by repeating similar discussions is shown in Figure 8(b). Figure 8(b) plots the magnitude of the current flowing through each part of the power supply wiring 400, as explained in the third embodiment in Figure 8(a) and the comparative example in Figure 5. The letters on the horizontal axis and the numerical values ​​on the vertical axis in Figure 8(b) are the same as those in Figure 6. Looking at this, it can be seen that the current flowing through the power supply wiring 400 is a maximum of 24Io[A] in the comparative example, while in the third embodiment it is a maximum of 4Io[A], showing a significantly higher current reduction effect. In this case, if there are 24 connection wires 109 and 3 first power supply sources 402, it is desirable to provide 24 / 3 = 8 connection wires between each first power supply source 402.

[0052] Here, consider the case where there are M connection wires 109 and N first power sources 402, and let X be the natural number obtained by truncating the decimal part of M / (2N). Here, M and N are natural numbers greater than or equal to 2. Considering the case where the ends of the power supply wiring 400 can be defined, X or (X+1) connection wires can be provided between any one end and the nearest first power source 402. Furthermore, it is desirable to provide 2 × X or (2 × X+1) connection wires between each first power source 402. For example, consider the case where there are 40 connection wires 109 and 6 first power sources 402. In this case, the natural number X obtained by truncating the decimal part of 40 / (2 × 6) is 3. Therefore, the first power source 402 is placed at a position separated by 3 or 4 connection wires 109 from one end of the power supply wiring 400. Similarly, another first power source 402 is placed at a position separated by three or four connecting wires 109 from another end. The remaining four first power sources 402 are placed at positions separated by six or seven connecting wires each. This arrangement makes it possible to efficiently distribute the current.

[0053] [Fourth Embodiment] Figure 9(a) is a top view showing the power supply wiring 400 and power sources supplying power to the imaging device 108 of the imaging apparatus according to the fourth embodiment. In the fourth embodiment, we will describe the case where the first power supply 1002a and the first power supply 1002b have different impedances. In the following explanation, we will use the case where the impedance of the first power supply 1002b is twice as large as that of the first power supply 1002a as an example. In this case, the ratio of their impedances is 1:2, so of the current Io[A] supplied to each connection wiring 109, the first power supply 1002a supplies 2 / 3Io[A] and the first power supply 1002b supplies 1 / 3Io[A].

[0054] Based on this premise, a current Io[A] supplied from the first power supply sources 1002a and 1002b flows through the power supply wiring 400 between connection wiring 109a and connection wiring 109b. Next, a current of 2Io[A], which is the sum of the currents supplied to connection wiring 109a and connection wiring 109b, flows through the power supply wiring 400 between connection wiring 109b and connection wiring 109c. Similarly, a current of 8Io[A], which is the sum of the currents from connection wiring 109a to connection wiring 109h, flows through the power supply wiring 400 between the first power supply source 1002a and connection wiring 109h. Furthermore, similarly, a current of 8Io[A], which is the sum of the currents from connection wiring 109x to connection wiring 109q, flows through the power supply wiring 400 between the first power supply source 1002b and connection wiring 109q.

[0055] Next, let's consider the current flowing through the power supply wiring 400 between the first power source 1002a and the connecting wiring 109i. In this case, the first power source 1002a supplies 2 / 3Io[A], which is the impedance ratio, to the 16 connecting wires from 109i to 109x. That is, the amount of current supplied by the first power source 1002a to the left of point A is 16 × 2 / 3Io[A]. On the other hand, the current supplied by the first power source 1002b is 8 × 1 / 3Io[A], which is the amount of current supplied by the 8 connecting wires from 109a to 109h, taking the impedance ratio into consideration. The point to note here is the direction of each current; the direction of the current supplied by the first power source 1002a and the direction of the current supplied by the first power source 1002b are opposite to each other. Therefore, to the left of point A, the current flowing is (16 × 2 / 3 - 8 × 1 / 3)Io[A] = 8Io[A], which is the difference in current we have calculated so far.

[0056] Figure 9(b) shows the results of performing similar calculations for each point. Figure 9(b) plots the magnitude of the current flowing through each part of the power supply wiring 400, as explained in the fourth embodiment in Figure 9(a) and the comparative example in Figure 5. The letters on the horizontal axis and the numerical values ​​on the vertical axis in Figure 9(b) are the same as those in Figure 6. As can be seen, while 24 Io [A] flowed in the comparative example, the maximum in the fourth embodiment is 8 Io [A], demonstrating that the current flowing through the power supply wiring 400 has been reduced.

[0057] Figure 10 plots the current flowing through the power supply wiring 400 at different impedance ratios when the impedance ratio between the first power supply source 1002a and the first power supply source 1002b is changed. This shows that the effect of distributing the current can be obtained when the impedance ratio is up to about 5 times.

[0058] [Fifth Embodiment] Figure 11(a) is a top view showing the power supply wiring 400 and power supply source that supplies power to the imaging device 108 of the imaging apparatus according to the fifth embodiment. In Figure 11(a), the first power supply source 402a is placed between the connecting wiring 109a and the connecting wiring 109b, and the first power supply source 402b is further placed between the connecting wiring 109w and the connecting wiring 109x. In this case as well, the same discussion as in the previous embodiments will be carried out.

[0059] First, let's consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109a. The current supplied from the first power sources 402a and 402b is the current Io[A] supplied to the connecting wiring 109a. Similarly, by the same reasoning, a current of Io[A] flows through the power supply wiring 400 between the first power source 402b and the connecting wiring 109x.

[0060] Next, let's consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109b. First, the first power source 402a supplies 11.5Io[A], which is half the current from the 23 connecting wirings from 109b to 109x. Next, the first power source 402b supplies 0.5Io[A], which is half the current from one connecting wiring 109a. Since these currents flow in opposite directions, the total current flowing through the power supply wiring 400 between the first power source 402a and the connecting wiring 109b is (11.5-0.5)Io=11Io[A]. Similarly, the power supply wiring 400 between the first power source 402b and the connecting wiring 109w also supplies 11Io[A].

[0061] Performing similar calculations between each connection wire 109, the magnitude of the current flowing through the power supply wiring 400 in the fifth embodiment and the comparative example is as shown in Figure 11(b). Figure 11(b) plots the magnitude of the current flowing through each part of the power supply wiring 400 as explained in the fifth embodiment in Figure 11(a) and the comparative example in Figure 5. Note that the letters on the horizontal axis and the numerical values ​​on the vertical axis in Figure 11(b) are the same as those in Figure 6. From this, it can be seen that the current flowing through the power supply wiring 400 is a maximum of 24Io[A] in the comparative example, while it is a maximum of 11Io[A] in the fifth embodiment, demonstrating the effect of distributing the current.

[0062] [Sixth Embodiment] Figure 12(a) is a top view showing the power supply wiring 400 and power supply source that supplies power to the imaging device 108 of the imaging apparatus according to the sixth embodiment. In Figure 12(a), the first power supply source 402a is placed between the connecting wiring 109k and the connecting wiring 109l, and the first power supply source 402b is placed between the connecting wiring 109m and the connecting wiring 109n. In this case as well, the same discussion as in the previous embodiments will be carried out.

[0063] First, the power supply wiring 400 between connection wirings 109a and 109b receives the current Io[A] required by connection wiring 109a, supplied by the first power sources 402a and 402b. By similar reasoning, a current of Io[A] also flows through the power supply wiring 400 between connection wiring 109w and connection wiring 109x. Between connection wirings 109b and 109c, the currents from connection wiring 109a and 109b are added together, resulting in a current of 2Io[A]. Similarly, a current of 2Io[A] flows between connection wiring 109v and connection wiring 109w. Repeating this process, the power supply wiring 400 between the first power source 402a and connection wiring 109k receives a total current of 11Io[A], equivalent to 11 connections from connection wiring 109a to connection wiring 109k. Similarly, the power supply wiring 400 between the first power source 402b and the connecting wiring 109n also carries a current of 11Io[A] from the 11 connecting wirings 109n to 109x.

[0064] Next, let's consider the power supply wiring 400 between the first power source 402a and the connecting wiring 109l. First, from the first power source 402a, 6.5Io[A] flows, which is half of the current 13Io[A] supplied from the connecting wiring 109l to the connecting wiring 109x. On the other hand, from the first power source 402b, 5.5Io[A] flows, which is half of the current supplied by 11 wires from the connecting wiring 109a to the connecting wiring 109k. Since these currents flow in opposite directions, ultimately, a current of (6.5-5.5)Io=1Io[A] flows through the power supply wiring 400 between the first power source 402a and the connecting wiring 109l. Similarly, a current of 1Io[A] also flows through the power supply wiring 400 between the first power source 402b and the connecting wiring 109m.

[0065] Performing similar calculations between each connection wire 109, the magnitude of the current flowing through the power supply wiring 400 in the sixth embodiment and the comparative example is as shown in Figure 12(b). Figure 12(b) plots the magnitude of the current flowing through each part of the power supply wiring 400, as explained in the sixth embodiment in Figure 12(a) and the comparative example in Figure 5. Note that the letters on the horizontal axis and the numerical values ​​on the vertical axis in Figure 12(b) are the same as those in Figure 6. From this, it can be seen that the current flowing through the power supply wiring 400 is a maximum of 24Io[A] in the comparative example, while it is a maximum of 11Io[A] in the fifth embodiment, demonstrating the effect of distributing the current.

[0066] The embodiments described herein can be modified as appropriate without departing from the technical concept. For example, multiple embodiments can be combined. Furthermore, some aspects of at least one embodiment can be deleted or replaced. Furthermore, new aspects can be added to at least one embodiment. The disclosures of this specification include not only what is explicitly stated herein, but also all matters that can be understood from this specification and the drawings attached herein. For example, any combination of each description is also part of the disclosures of this specification. For example, if there is a statement "A is greater than or equal to B" and a statement "C is less than or equal to D", the form "A is greater than or equal to B, and C is less than or equal to D" is part of the disclosures of this specification. In this specification, "A is greater than or equal to B" (A is any element, B is any index) means "A is equal to B, or A is greater than B". "C is less than or equal to D" (C is any element, D is any index) means "C is equal to D, or C is less than D (less than C)". Furthermore, the disclosures of this specification include the complements of the individual concepts described herein. In other words, if this specification contains a statement such as "E is F" (where E and F are arbitrary), then even if the statement for the case where "E is not F" is omitted, this specification can be said to disclose the case where "E is not F". This is because the statement "E is F" presupposes that the case where "E is not F" is being considered. [Explanation of Symbols]

[0067] 100...Electronic equipment, 104...Imaging device, 107...Printed circuit board, 108...Imaging device, 109...Connection wiring, 400...Power wiring, 402...First power source, 403...Second power source

Claims

1. An imaging device in which multiple photoelectric conversion elements are arranged in an array, The aforementioned imaging device is mounted on a wiring component on which power supply wiring is provided, Multiple connection wires that connect the power supply wiring and the imaging device to each other, At least two power sources connected to the aforementioned power wiring, It comprises at least one power supply source connected to the power wiring, The at least two power sources and the at least one power source supply power to the imaging device via the power wiring and the plurality of connection wiring. At the horizontal synchronization frequency of the imaging device, the at least two power sources have a lower impedance than the at least one power source. An imaging device characterized in that at least one of the plurality of connecting wires is connected to the wiring path connecting the first power supply source and the second power supply source among the at least two power supply sources in the power supply wiring.

2. An imaging device in which multiple photoelectric conversion elements are arranged in an array, The aforementioned imaging device is mounted on a wiring component on which power supply wiring is provided, Multiple connection wires that connect the power supply wiring and the imaging device to each other, It has at least two power sources connected to the aforementioned power wiring, The at least two power sources supply power to the imaging device via the power supply wiring and the plurality of connection wiring. In the range of 20 kHz to 200 kHz, the at least two power sources have an impedance of 5 [Ω] or less. An imaging device characterized in that at least one of the plurality of connecting wires is connected to the wiring path connecting the first power supply source and the second power supply source among the at least two power supply sources in the power supply wiring.

3. The imaging apparatus according to claim 1 or 2, characterized in that the first power source and the second power source are capacitors having the same standard capacitance value.

4. The imaging apparatus according to claim 1 or 2, characterized in that one of the first power source and the second power source is an integrated circuit, and the other of the first power source and the second power source is a capacitor.

5. The imaging apparatus according to claim 1 or 2, characterized in that one of the first power supply source and the second power supply source is a regulator.

6. The imaging apparatus according to any one of claims 1 to 5, characterized in that the horizontal synchronization frequency of the imaging device is from 20 kHz to 200 kHz.

7. The imaging apparatus according to any one of claims 1 to 6, characterized in that the impedance ratio of the first power source and the second power source is within 5 times.

8. The imaging apparatus according to any one of claims 1 to 7, characterized in that, when the number of the plurality of connection wires is M, and there are N of the at least two power sources, and X is a natural number obtained by dividing M by 2N and truncating the decimal part, there are X or (X+1) connection wires between any end of the power wiring and the power source among the N power sources that is closest to any end of the power wiring, and there are 2 × X or (2 × X+1) connection wires between each of the N power sources.

9. The imaging apparatus according to any one of claims 1 to 8, characterized in that the number of the plurality of connection wires is 12 or more, and the number of the at least two power supply sources connected to the power supply wire is 6 or more.

10. The imaging apparatus according to any one of claims 1 to 9, characterized in that the first power source and the second power source are mounted on the wiring component.

11. The imaging apparatus according to any one of claims 1 to 10, characterized in that the plurality of connecting wires are bonding wires.

12. The imaging apparatus according to any one of claims 1 to 11, characterized in that the first power source and the second power source include at least one of a capacitive component and an inductance component.

13. The imaging apparatus according to any one of claims 1 to 12, characterized in that the impedances of the first power source and the second power source are frequency-dependent.

14. The imaging apparatus according to any one of claims 1 to 13, characterized in that the power supply wiring has an open loop shape along each of the four sides of the quadrilateral imaging device.

15. The imaging apparatus according to any one of claims 1 to 14, characterized in that the power supply wiring does not overlap with the imaging area of ​​the imaging device in an area of ​​90% or more of the imaging area.

16. The imaging device according to any one of claims 1 to 15, characterized in that the imaging device includes a first semiconductor layer having a plurality of photoelectric conversion elements, a second semiconductor layer stacked on the first semiconductor layer and having an integrated circuit, and a wiring layer located between the first semiconductor layer and the second semiconductor layer.

17. The imaging area of ​​the aforementioned imaging device is 200 mm². ２ Above 300mm ２ or more, or 800 mm ２ The imaging apparatus according to any one of claims 1 to 16, characterized in that it is as described above.

18. An imaging device according to any one of claims 1 to 17, An electronic device comprising a processing device for processing signals output from the imaging device.

19. An imaging device according to any one of claims 1 to 17, An electronic device comprising a display device that displays an image captured by the aforementioned imaging device.

20. An imaging device according to any one of claims 1 to 17, An electronic device comprising a drive device for moving the aforementioned imaging device.

Images