Imaging unit and imaging device

Abstract

SOLUTION: An imaging unit comprises: a mounting substrate on which an imaging device imaging a subject and a connector are mounted; an electric power source substrate on which the connector is mounted and includes an electric power source circuit unit including a regulator; and a flexible substrate with one end connected to the connector on the mounting substrate and the other end connected to the connector on the electric power source substrate, wherein the electric power source circuit unit outputs a first electric power source voltage, and feeds back a second electric power source voltage applied to the imaging device via the flexible substrate on the basis of the first electric power source voltage, via the flexible substrate, and corrects the first electric power source voltage on the basis of a third electric power source voltage appearing on the electric power source substrate side due to the feedback.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an imaging unit and an imaging device. [Background technology]

[0002] Solid-state imaging devices including a pixel array in which a plurality of pixels are arranged are known (for example, Patent Document 1). Conventionally, an increase in power consumption has been a problem. [Prior art document] [Patent documents] [Patent Document 1] JP 2011-176616 A Summary of the Invention

[0003] In a first aspect of the present invention, there is provided an imaging unit. The imaging unit may include a mounting board on which an imaging element for imaging a subject and a connector are mounted. The imaging unit may include a power supply board on which the connector is mounted and which has a power supply circuit section including a regulator. The imaging unit may include a flexible board having one end connected to the connector of the mounting board and the other end connected to the connector of the power supply board. The power supply circuit section may output a first power supply voltage, feed back a second power supply voltage applied to the imaging element via the flexible board based on the first power supply voltage via the flexible board, and correct the first power supply voltage based on a third power supply voltage that appears on the power supply board side by the feedback.

[0004] The above summary of the invention does not list all of the necessary features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic cross-sectional view of a camera 10, which is an example of an imaging device, according to an embodiment. [Diagram 2] FIG. 4 is a schematic top view of a portion of an imaging unit 40 according to one embodiment. [Diagram 3]FIG. 3 is a cross-sectional view that illustrates a schematic cross section taken along the line AA in FIG. 2. [Figure 4] 2 is a schematic circuit diagram of an imaging unit 40 according to an embodiment. FIG. [Diagram 5] 2 is a schematic circuit diagram of an imaging unit 41 according to an embodiment. FIG. [Figure 6] FIG. 6 is a schematic circuit diagram of a power supply unit 53 in FIG. [Figure 7] FIG. 2 is a schematic circuit diagram of an imaging unit 42 according to one embodiment. [Figure 8] FIG. 2 is a schematic circuit diagram of an imaging unit 43 according to an embodiment. [Figure 9] 4 is a graph showing an example of the relationship between a change in current consumption and a change in terminal voltage of an image sensor 100 according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0007] 1 is a schematic cross-sectional view of a camera 10, which is an example of an imaging device, according to an embodiment. The camera 10 is, for example, a digital compact camera. The camera 10 includes a lens unit 20 and a camera body 30.

[0008] Lens unit 20 has an optical system inside its barrel, and the optical system defines optical axis 22. Lens unit 20 is attached to camera body 30. Lens unit 20 may be housed inside camera body 30 and may extend outward when in use as shown in the figure.

[0009] Lens unit 20 guides an incident subject light beam into housing 31 of camera body 30. Note that, while lens unit 20 shown in Fig. 1 includes two lenses and an aperture simply for clarity of explanation, it is not limited to this configuration.

[0010] The camera body 30 has an imaging unit 40 and a display unit 88. A subject light flux incident on the lens unit 20 is guided to the imaging unit 40 by the lens unit 20.

[0011] The imaging unit 40 includes an imaging element 100 for capturing an image of a subject, a mounting board 120 having a first main surface 111 and a second main surface 112, a connector 180 mounted on the second main surface 112 of the mounting board 120, a first flexible board 250 and a second flexible board 260, and a board unit 60 including a board 62 connected to the mounting board 120 by the first flexible board 250 and the second flexible board 260. The imaging unit 40 in this embodiment further includes a frame 140 and a cover glass 160. The imaging unit 40 does not necessarily have to include the connector 180, the frame 140, and the cover glass 160. The board 62 is an example of a power supply board. In the following description, the board 62 may be referred to as a power supply board.

[0012] The imaging element 100 is, for example, a CMOS image sensor or a CCD image sensor, and has a rectangular shape in its main plane. The imaging element 100 is mounted on a first main surface 111 of a mounting board 120. The imaging element 100 is an example of an imaging element.

[0013] In this embodiment, the direction along the optical axis 22 is defined as the z-axis direction. That is, the direction in which the subject light beam is incident on the imaging surface of the image sensor 100 is defined as the z-axis direction. Specifically, the direction in which the subject light beam is incident is defined as the negative z-axis direction, and the opposite direction is defined as the positive z-axis direction. The longitudinal direction of the image sensor 100 is defined as the x-axis direction. The lateral direction of the image sensor 100 is defined as the y-axis direction. Specifically, the x-axis and y-axis directions are defined as the directions shown in FIG. 1. The x-axis, y-axis, and z-axis are in a right-handed Cartesian coordinate system.

[0014] When defined in this way, the mounting board 120, the board 62, and the display unit 88 in this embodiment are arranged in this order in the negative z-axis direction. For convenience of explanation, the positive z-axis direction may be referred to as the front, the front side, etc. The negative z-axis direction may be referred to as the rear, the rear side, etc. The side in the negative z-axis direction may be referred to as the rear side, etc.

[0015] The board 62 of the board unit 60 is disposed at a position in the negative z-axis direction of the imaging unit 40. The connector 182, the connector 184, the MPU 51, the ASIC 52, and the power supply unit 53 are mounted on the board 62 of the board unit 60. Note that other electronic circuits may be additionally or alternatively mounted on the board 62. Note that instead of a single board 62 on which components such as the power supply unit 53 are mounted, the board unit 60 may include multiple boards on which each component is individually mounted one by one, multiple boards on which several components are collectively mounted, or multiple boards combining these.

[0016] The MPU 51 is responsible for the overall control of the camera 10. The ASIC 52 processes the image signal output from the imaging element 100. In this embodiment, the ASIC 52 receives the image signal from the imaging element 100 via the mounting board 120, the connector 180, the first flexible board 250, and the connector 184. In this manner, one end of the first flexible board 250 is connected to the connector 180 of the mounting board 120, and the other end is connected to the connector 184 of the board 62.

[0017] Power supply unit 53 includes a battery attached to camera 10 and a power supply circuit that supplies power stored in the battery to each part of camera 10. Power supply unit 53 in this embodiment supplies current to image sensor 100 via connector 182, second flexible substrate 260, connector 180, and mounting substrate 120. In this manner, second flexible substrate 260 has one end connected to connector 180 of mounting substrate 120, and the other end connected to connector 182 of substrate 62.

[0018] The ASIC 52 generates image data for display based on the image signal from the imaging element 100. The ASIC 52 performs, for example, image processing and compression processing on the image signal from the imaging element 100 to generate image data for display.

[0019] The image data for display generated by the ASIC 52 is output to the display unit 88. The image data may be recorded on a recording medium attached to the camera body 30. The recording medium may be configured to be detachable from the camera body 30.

[0020] The display unit 88 is disposed at a position in the negative z-axis direction of the board 62 of the board unit 60. For example, a liquid crystal panel or the like can be used as the display unit 88. The display surface of the display unit 88 appears on the rear surface of the camera body 30. The display unit 88 displays an image based on image data for display generated by the ASIC 52.

[0021] The imaging unit 40 may include two or more connectors. In other words, two or more connectors may be mounted on the second main surface 112 of the mounting board 120. Also, a separate flexible board may be connected to each of the two or more connectors. Each pair of a connector and a flexible board may be specialized for a specific purpose. Also, the purposes of a plurality of such pairs may be partially or entirely common to each other.

[0022] Fig. 2 is a top view showing a schematic view of a part of the imaging unit 40 according to one embodiment. Fig. 3 is a cross-sectional view showing a schematic view of the AA cross section of Fig. 2. However, in Fig. 3, in addition to the part of the imaging unit 40 shown in solid lines, a bracket 150, a first flexible substrate 250, and a second flexible substrate 260 are shown in dashed lines.

[0023] The imaging element 100 includes an imaging region 101 and a peripheral region 102. As shown in Fig. 2, both the imaging region 101 and the peripheral region 102 are rectangular in plan view.

[0024] The imaging region 101 is formed in the center of the image sensor 100. In the imaging region 101, a plurality of photoelectric conversion elements that perform photoelectric conversion on subject light are arranged two-dimensionally, thereby forming the imaging surface of the image sensor 100. Each pixel is configured to include one or a plurality of photoelectric conversion elements.

[0025] The peripheral area 102 is located around the imaging area 101. The peripheral area 102 includes a processing circuit 104 that reads out image signals obtained by photoelectric conversion in the photoelectric conversion elements and performs signal processing. The processing circuit 104 includes an AD conversion circuit that converts the output image signals into digital signals. The processing circuit 104 also includes a transmission circuit 105 for transmitting the image signals.

[0026] The imaging element 100 is mounted on a mounting substrate 120 using a COB (Chip On Board) method. The imaging element 100 is fixed to the mounting substrate 120 by an adhesive 210. The adhesive 210 is, for example, a thermosetting adhesive. Other adhesives described below are also, for example, thermosetting adhesives.

[0027] The imaging element 100 is electrically connected to the mounting board 120 via bonding wires 110. An image signal converted into a digital signal by an AD conversion circuit of the imaging element 100 is output to the mounting board 120 via the bonding wires 110. The imaging element 100 may be mounted on the mounting board 120 by flip-chip mounting.

[0028] The mounting board 120 includes a first layer 121, a core layer 207, and a second layer 122. The first layer 121 includes a solder resist layer 201, a wiring layer 202, an insulating layer 203, a wiring layer 204, and an insulating layer 205. The second layer 122 includes an insulating layer 215, a wiring layer 214, an insulating layer 213, a wiring layer 212, and a solder resist layer 211. The mounting board 120 is a multilayer core board having the core layer 207 as a core layer.

[0029] On the mounting board 120, the following layers are arranged in the negative z-axis direction in the following order: solder resist layer 201, wiring layer 202, insulating layer 203, wiring layer 204, insulating layer 205, core layer 207, insulating layer 215, wiring layer 214, insulating layer 213, wiring layer 212, and solder resist layer 211.

[0030] The insulating layer 203, the insulating layer 205, the insulating layer 215, and the insulating layer 213 are, for example, resin layers. The thickness of each of the insulating layers 203, etc. in the z-axis direction is, for example, 20 μm to 50 μm.

[0031] The wiring layer 202, the wiring layer 204, the wiring layer 214, and the wiring layer 212 include wiring patterns. The material of the wiring layer 202, etc. may be an alloy of nickel and iron (e.g., 42 alloy, 56 alloy), copper, aluminum, etc. The thickness of each of the wiring patterns of the wiring layer 202, etc. is, for example, 10 μm to 50 μm.

[0032] The core layer 207 is made of a metal. When the core layer 207 is made of a metal, the material of the core layer 207 may be, for example, an alloy of nickel and iron (for example, 42alloy, 56alloy), copper, aluminum, or the like. The thickness of the core layer 207 is thicker than any of the wiring layers 202, etc. The thickness of the core layer 207 is thicker than any of the insulating layers 203, etc. Specifically, the thickness of the core layer 207 is, for example, 0.1 mm to 0.8 mm.

[0033] The rigidity of the core layer 207 is higher than the rigidity of any of the wiring layers 202 etc. The rigidity of the core layer 207 may be higher than the rigidity of the first layer 121. The rigidity of the core layer 207 may be higher than the rigidity of the second layer 122.

[0034] The core layer 207 may be made of resin. When the core layer 207 is made of resin, the core layer 207 may be made of, for example, FR4 or a material having a higher elastic modulus than FR4. When the core layer 207 is made of resin, the core layer 207 is sandwiched between wiring layers in the z-axis direction. For example, when the core layer 207 is made of resin, the solder resist layer 201, the wiring layer 202, the insulating layer 203, the wiring layer 204, the core layer 207, the wiring layer 214, the insulating layer 213, the wiring layer 212, and the solder resist layer 211 may be arranged in this order in the negative z-axis direction. When two additional wiring layers are arranged, an additional insulating layer in contact with wiring layer 204 and an additional wiring layer in contact with core layer 207 are arranged in the negative direction of the z-axis between wiring layer 204 and core layer 207, and an additional wiring layer in contact with core layer 207 and an additional insulating layer in contact with wiring layer 214 are arranged in the negative direction of the z-axis between core layer 207 and wiring layer 214.

[0035] Thus, mounting substrate 120 is a multi-layer core substrate having a metal core or a resin core. Mounting substrate 120 may have a thickness of, for example, 0.3 mm to 1.5 mm.

[0036] At least a part of the wiring layer 202 is used for a wiring pattern that receives an image signal output from the image sensor 100 via the bonding wire 110. The wiring layer 202 includes a bonding pad 240 to which the bonding wire 110 is connected.

[0037] The wiring patterns included in the wiring layer 204 and the wiring patterns included in the wiring layer 214 can be used as, for example, ground lines, power supply lines, and the like.

[0038] The imaging element 100 is disposed on the solder resist layer 201, and is electrically connected to a bonding pad 240 by a bonding wire 110. The bonding pad 240 and the wiring layer 212 are electrically connected by a via 131 that penetrates the first layer 121 and the core layer 207. The via 131 is covered by an insulator 132. An image signal output from the imaging element 100 is transmitted to the wiring layer 212 via the wiring layer 202 and the via 131.

[0039] Electronic components such as the connector 180, the bypass capacitor group 185, and the circuit group 187 are mounted on the solder resist layer 211. In other words, these electronic components are mounted on the second main surface 112 of the mounting board 120, which is opposite to the first main surface 111 on which the imaging element 100 is mounted. Other electronic components such as resistors, regulators, and transistors may also be included on the solder resist layer 211.

[0040] These electronic components are electrically connected to the wiring layer 212 by lead members. The lead members are fixed to the wiring layer 212 with solder or the like. A part of the wiring layer 212 is exposed to the outside from an opening formed in the solder resist layer 211 to provide an electrode such as a land.

[0041] The frame 140 is made of resin. The frame 140 is adhered to the solder resist layer 201 of the mounting board 120 by adhesive parts 220. That is, the mounting board 120 is fixed to the frame 140.

[0042] The frame 140 may be configured by inserting a metal body into resin. The material of the metal body may be an alloy of nickel and iron (e.g., 42alloy, 56alloy), copper, or aluminum. If a lightweight material such as aluminum is used as the material of the metal body, the weight of the frame 140 can be reduced. If a material with a relatively high thermal conductivity such as copper is used as the material of the metal body, the heat dissipation characteristics from the frame 140 can be improved.

[0043] The frame 140 has a first surface 141, a second surface 142, a third surface 143, a fourth surface 144, a fifth surface 145, and a sixth surface 146. The sixth surface 146 forms an opening 138. The sixth surface 146 forms an inner wall surface of the frame 140. The opening 138 is formed, for example, in a central portion in the xy plane. The imaging element 100 mounted on the first main surface 111 of the mounting substrate 120 is located in the opening 138.

[0044] The first surface 141 is a surface that is bonded to the cover glass 160 by the adhesive portion 230. The first surface 141 is a surface that contacts an end portion of the sixth surface 146. The first surface 141 is formed along the outer edge of the sixth surface 146. The first surface 141 is a surface that is approximately parallel to the xy plane.

[0045] The second surface 142 is a surface that contacts an end portion of the first surface 141. The second surface 142 is a surface that is formed along the outer edge of the first surface 141. The second surface 142 has a surface that is approximately parallel to the yz plane and a surface that is approximately parallel to the xz plane.

[0046] The third surface 143 is a surface that is in contact with an end portion of the second surface 142. The third surface 143 is a surface that is approximately parallel to the xy plane, and is a surface that is approximately parallel to the first surface 141.

[0047] The fourth surface 144 is a surface that contacts an end portion of the third surface 143. The fourth surface 144 is a surface that is formed along the outer edge of the third surface 143. The fourth surface 144 has a surface that is approximately parallel to the yz plane and a surface that is approximately parallel to the xz plane.

[0048] The fifth surface 145 is a surface that contacts an end of the fourth surface 144. The fifth surface 145 is a surface that is formed along the outer edge of the fourth surface 144. The fifth surface 145 is a surface that is approximately parallel to the xy plane. The fifth surface 145 is a surface that is approximately parallel to the first surface 141 and the third surface 143. The fifth surface 145 is a surface that is bonded to the solder resist layer 201 of the mounting board 120 by the adhesive portion 220. The fifth surface 145 faces the adhesive portion 220. The fifth surface 145 is a surface that contacts an end of the sixth surface 146. The fifth surface 145 is formed along the outer edge of the sixth surface 146.

[0049] The frame 140 has a step portion formed by a first surface 141, a second surface 142, and a third surface 143. The frame 140 has mounting holes 148 as mounting portions. The frame 140 has, for example, three mounting holes 148. All three mounting holes 148 are holes that penetrate from the third surface 143 to the fifth surface 145. All three mounting holes 148 are used to mount the imaging unit 40 to another structure, such as the housing 31 of the camera body 30.

[0050] The frame 140 is fixed to the bracket 150 by, for example, screwing it with screws 149 through three mounting holes 148. The bracket 150 is fixed to the housing 31 of the camera body 30 by, for example, screwing it. Thus, the imaging unit 40 is fixed to the housing 31 of the camera body 30.

[0051] When the frame 140 and the bracket 150 are fastened to each other using the mounting holes 148 with, for example, metal screws 149, a heat transfer path can be formed for dissipating heat generated when the image sensor 100 is operating, via the screws 149, toward the housing 31.

[0052] The frame 140 has a positioning hole 147. The frame 140 has, for example, two positioning holes 147. Both of the two positioning holes 147 are holes that penetrate from the third surface 143 to the fifth surface 145. Of the two positioning holes 147, one positioning hole is formed as a fitting hole, and the other positioning hole 147 is formed as an elongated hole.

[0053] The frame 140 is positioned relative to the bracket 150 by using two positioning holes 147. For example, two positioning pins provided on the bracket 150 are inserted into the two positioning holes 147, thereby positioning the frame 140 and the bracket 150. The frame 140 is fixed in a state in which it is positioned relative to the bracket 150. Thus, the imaging unit 40 is fixed in a state in which it is positioned in the housing 31. Note that the frame 140 and the bracket 150 may be fixed to a structure other than the housing 31.

[0054] The imaging unit 40 may be fixed to the housing 31 without using the bracket 150. The imaging unit 40 may be fixed to the housing 31 by being fastened through the three mounting holes 148 with, for example, screws.

[0055] The cover glass 160 is formed of, for example, borosilicate glass, quartz glass, alkali-free glass, heat-resistant glass, quartz, etc. The cover glass 160 is translucent. The thickness of the cover glass 160 is, for example, 0.5 mm to 0.8 mm.

[0056] The cover glass 160 is used to seal the imaging element 100 housed in the opening 138 of the frame 140. More specifically, the cover glass 160 is fixed to the frame 140 so as to cover the opening 138 of the frame 140. The cover glass 160 is fixed to the frame 140 after the imaging element 100, the bonding wires 110, and the frame 140 are mounted on the mounting board 120. The cover glass 160 is adhered to the frame 140 by an adhesive part 230. Since the cover glass 160 is translucent, the adhesive part 230 may be a photocurable adhesive.

[0057] The cover glass 160, together with the frame 140 and the mounting board 120, seals the space within the opening 138. Therefore, the imaging element 100 located within the opening 138 is disposed in a space sealed by the mounting board 120, the frame 140, and the cover glass 160. This makes the imaging element 100 less susceptible to the effects of the external environment. For example, the imaging element 100 is less susceptible to the effects of moisture present outside the space. This makes it possible to prevent deterioration of the imaging element 100.

[0058] 4 is a schematic circuit diagram of the imaging unit 40 according to one embodiment. On the board 62 of the imaging unit 40, the power supply unit 53 has a power supply circuit section 300.

[0059] The power supply circuit section 300 mounted on the substrate 62 outputs a first power supply voltage V1. The power supply circuit section 300 feeds back, via the second flexible substrate 260 and the like, a second power supply voltage V1' that is applied to the image sensor 100 based on the first power supply voltage V1. The power supply circuit section 300 further corrects the first power supply voltage V1 based on a third power supply voltage that appears on the substrate 62 side by feedback. In the following description, the first power supply voltage V1 may be referred to as an output voltage V1 of the power supply circuit section 300. Similarly, the second power supply voltage V1' may be referred to as a terminal voltage V1' of the image sensor 100.

[0060] In other words, in order to keep the voltage applied to the imaging element 100 constant, the power supply circuit section 300 forms a feedback path that feeds back the voltage applied to the imaging element 100 to the power supply circuit section 300 together with the circuit group 187 of the mounting board 120 via the second flexible board 260 etc. It can also be said that the power supply circuit section 300 monitors the voltage applied to the imaging element 100.

[0061] More specifically, the power supply circuit section 300 includes a DCDC 311, which is an example of a regulator. The power supply circuit section 300 according to the present embodiment further includes a coil 312, a resistive element 313, a resistive element 314, and a capacitor 315. The feedback path described above includes at least the coil 312, the resistive element 313, and the resistive element 314.

[0062] One end of the DCDC 311 is connected to the positive power supply of the power supply unit 53, and receives a positive voltage Vcc from the positive power supply. The other end of the DCDC 311 is electrically connected to the input terminal of the image sensor 100 via the connector 182, the power line 261 of the second flexible substrate 260, and the connector 180.

[0063] The DCDC311 performs duty modulation (pulse width modulation) on the positive voltage Vcc input from the positive power supply, and outputs the output voltage Vdcdc. The voltage can be reduced to a desired level by smoothing it with the coil 312 and capacitor 315 in the subsequent stage. The terminal voltage V1' of the image sensor 100 is fed back to the DCDC311 via the above-mentioned feedback path. The DCDC311 has a drive capability that can adjust the output voltage Vdcdc of the DCDC311 by itself so that the fed back voltage V1' is within the normal voltage range Vsen of the terminal voltage defined by the image sensor 100.

[0064] The voltage V1' near the input terminal of the image sensor 100 changes due to a change in the consumption current flowing into the image sensor 100. Therefore, for example, when the amount of current flowing through the DCDC 311 increases and the terminal voltage V1' drops, the DCDC 311 increases the duty ratio of Vdcdc so that the terminal voltage V1' falls within the normal voltage range Vsen. In other words, the output voltage V1 of the power supply circuit unit 300 is boosted to raise the terminal voltage V1'. This boost operation is possible within the drive capacity of the DCDC 311.

[0065] The coil 312 is disposed on a path between the other end of the DCDC 311 and the connector 182. That is, the coil 312 is connected in series with the DCDC 311 between the positive power supply of the power supply unit 53 and the imaging element 100. The coil 312 has an inductance L.

[0066] The resistive element 313 and the resistive element 314 are connected in series between the imaging element 100 and the DCDC 311. More specifically, one end of the resistive element 313 is electrically connected to the input terminal of the imaging element 100 via the connector 182, the feedback line 262 of the second flexible substrate 260, and the connector 180. The other end of the resistive element 313 is connected to one end of the resistive element 314 and the DCDC 311. The other end of the resistive element 314 is connected to the ground Gnd and the DCDC 311. The resistive element 313 and the resistive element 314 have resistance values ​​Rfb1 and Rfb2, respectively.

[0067] A capacitor 315 indicated by the symbol C in the figure has one end connected to the ground Gnd of the substrate 62 and the other end connected to the output side of the DCDC 311, and smoothes the change in the current supplied from the positive power supply to the image sensor 100 via the DCDC 311. Note that, similarly to the capacitor 315, a capacitor 188 indicated by the symbol C in the figure has one end connected to the ground Gcob of the mounting substrate 120 and the other end connected to the input terminal side of the image sensor 100, and smoothes the change in the current supplied from the positive power supply of the power supply unit 53 to the image sensor 100.

[0068] As shown in the figure, power line 261 of second flexible substrate 260 has a resistance value r2, and the pins of connectors 180, 182 connected to power line 261 have a resistance value r1. Furthermore, feedback line 262 of second flexible substrate 260 has a resistance value r2'', and the pins of connectors 180, 182 connected to feedback line 262 have a resistance value r1". Furthermore, ground line 263 of second flexible substrate 260 has a resistance value r2', and the pins of connectors 180, 182 connected to ground line 263 have a resistance value r1'.

[0069] In recent years, the power consumption or current consumption of image sensors has been increasing due to the high pixel density and high speed readout of image sensors. Furthermore, stacked image sensors equipped with large-scale circuits such as memory have also appeared, accelerating the increase in power consumption of image sensors. On the other hand, the period during which the image sensor is in operation includes a period during which a wide variety of processes are performed, such as a period during which charges are stored in pixels, a period during which the charges of each pixel are coded into digital values ​​corresponding to the charges of each pixel, i.e., a period during which A / D conversion is performed, a period during which brightness data is output from the image sensor, and a period during which digital data is stored in the memory of the image sensor, and these periods may overlap with each other. Therefore, in an image sensor, even if the amount of current consumption during a certain period is normal, the amount of current consumption may suddenly increase to an excessive amount that greatly exceeds the normal amount in the next period, and the amount of current consumption may return to the normal amount in the next period, and the amount of current consumption may suddenly change.

[0070] As described above, the terminal voltage V1' of the image sensor is determined to be within a voltage range Vsen within which the image sensor can operate. If the terminal voltage V1' of the image sensor falls outside this voltage range Vsen, this is detected as an error. If the error occurs repeatedly, the operation of the image sensor may become unstable, making it impossible to obtain a normal image, or the operation of the image sensor may stop.

[0071] When the power supply unit that supplies power to the image sensor is mounted on a power supply board other than the mounting board on which the image sensor is mounted, and the mounting board and the power supply board are connected by a connector and harness (hereinafter simply referred to as a harness with connector), a voltage drop (sometimes referred to as a voltage drop) occurs due to the resistance component of the harness with connector. The voltage drop is proportional to the amount of current supplied to the image sensor, and the greater the amount of current, the greater the voltage drop.

[0072] If a regulator for supplying a stable voltage to the image sensor is mounted on the power supply board, and a feedback path for keeping the regulator's output voltage constant is formed only on the power supply board, the terminal voltage V1' of the image sensor on the mounting board side is not fed back to the regulator on the power supply board side, so the regulator's output voltage does not take the above-mentioned voltage drop into consideration. Therefore, if the image sensor consumes a large amount of current, the terminal voltage V1' of the image sensor is more likely to transiently fall below the specified lower voltage limit of the above-mentioned voltage range Vsen due to a voltage drop.

[0073] On the other hand, when the regulator is mounted on the mounting board, if the amount of current flowing through the regulator increases, the switching noise and thermal noise of the regulator may increase, degrading the imaging performance of the image sensor. For example, switching noise is caused by the switching operation of the switching regulator (DCDC) resonating with the sequence operation inside the image sensor, and thermal noise is caused by a linear regulator such as an LDO. Thermal noise is a degradation of imaging performance caused by heat generated in the linear regulator being conducted to the image sensor via the mounting board. For example, it may reduce the number of continuous shots that the camera can take because it is more likely to exceed the upper temperature limit, shorten the exposure time of the camera, or make part of the captured image look white with white noise.

[0074] Therefore, according to the imaging unit 40, the board 62 connected to the mounting board 120 via the second flexible board 260 etc. has a power supply circuit section 300 including a DCDC 311, and the power supply circuit section 300 feeds back the voltage applied to the imaging element 100 on the mounting board 120 via the second flexible board 260 etc. Also, according to the imaging unit 40, the mounting board 120 is not provided with a regulator.

[0075] More specifically, the power supply circuit unit 300 outputs a first power supply voltage V1, but the second power supply voltage V1' applied to the image sensor 100 via the second flexible substrate 260 and the like based on the first power supply voltage V1 is smaller than V1 by the voltage drop caused by the contact resistance r1 of the connectors 180 and 182 and the transmission resistance r2 of the power supply line 261 of the second flexible substrate 260. If the current flowing through the DCDC 311, the connector 182, the second flexible substrate 260, and the connector 180 is I1, the voltage drop is I1(2r1+r2)[V]. A part of the current I1 is diverted by the feedback current Ifb just before the input side of the image sensor 100 by the above feedback path. Therefore, the second power supply voltage V1' is V1'=V1-(I1-Ifb)(2r1+r2) based on the ground potential Gnd of the substrate 62.

[0076] The power supply circuit unit 300 feeds back the second power supply voltage V1' to the DCDC 311 via the second flexible substrate 260 and the like. The third power supply voltage appearing on the substrate 62 side due to the feedback is smaller than V1' by the voltage drop Ifb (2r1''+r2'') caused by the contact resistance r1'' of the connectors 180, 182 and the transmission resistance r2'' of the feedback line 262 of the second flexible substrate 260. The feedback current Ifb is expressed as Ifb=V1' / (Rfb2+Rfb1+2r1''+r2'') using the terminal voltage V1'. For example, by maximizing the resistance Rfb1, the feedback current Ifb can be made smaller than the current I1, and the voltage drop Ifb (2r1''+r2'') in the feedback path can be made negligibly small. Since the feedback current Ifb flows to the ground Gnd via the resistive element 314, it can be expressed as Vfb=Ifb·Rfb2.

[0077] The power supply circuit unit 300 corrects the first power supply voltage V1 based on the third power supply voltage. More specifically, the power supply circuit unit 300 feeds back V1' to the DCDC 311 and outputs a voltage that compensates for the voltage drop I1 (2r1+r2) for the first power supply voltage V1.

[0078] In this way, according to the imaging unit 40 of the present embodiment, it is possible to output a voltage that has been boosted in advance by the amount of voltage drop I1(2r1+r2) [V] in the second flexible substrate 260, etc., from the power supply unit 53 of the substrate 62 other than the mounting substrate 120, and this makes it possible to reduce the possibility that the terminal voltage V1' of the imaging element 100 will fall below the specified lower voltage limit of the imaging element 100, as described above.

[0079] Moreover, according to the imaging unit 40, the above-mentioned feedback path is formed between the board 62 on which the power supply unit 53 is mounted, the second flexible board 260, etc., and the mounting board 120 on which the imaging element 100 is mounted. As a result, according to the imaging unit 40, even when the amount of current consumption of the imaging element 100 is about to change suddenly as described above, the DCDC 311 of the power supply circuit section 300 in the power supply unit 53 adjusts the output voltage V1 of the power supply circuit section 300, thereby making it possible to keep the terminal voltage V1' of the imaging element 100 within the above-mentioned voltage range Vsen.

[0080] As described above, according to the imaging unit 40, the prescribed voltage of the imaging element 100 can be complied with, and therefore stable operation of the imaging element 100 can be ensured.

[0081] The power supply unit 53 of the imaging unit 40 according to this embodiment outputs a voltage corrected based on the ground potential Gnd of the substrate 62, and does not correct the voltage drop (I1-Ifb)(2r'+r2') when the feedback current I1-Ifb passing through the imaging element 100 flows from the ground Gcob of the mounting substrate 120 through the connector 180, the ground line 263 of the second flexible substrate 260, and the connector 182 to the ground Gnd of the substrate 62. Therefore, the terminal voltage V1' of the imaging element 100 may deviate from the above-mentioned voltage range Vsen based on the ground potential Gcob of the mounting substrate 120. Therefore, the imaging unit 40 may increase the number of pins of the ground line 263 in the connector harness. This allows the imaging unit 40 to bring r' and r2' closer to 0Ω, and minimize the influence of the above-mentioned voltage drop (I1-Ifb)(2r'+r2'). Therefore, the imaging unit 40 can further reduce the possibility that the terminal voltage V1' of the imaging element 100 falls outside the above-mentioned voltage range Vsen.

[0082] Furthermore, according to the imaging unit 40 of this embodiment, since a regulator is not provided on the mounting board 120, it is possible to prevent the switching noise and thermal noise of the regulator from affecting the imaging element 100, and therefore it is possible to prevent the imaging performance of the imaging element 100 from being deteriorated.

[0083] In the power supply unit 53 on the substrate 62, the DCDC 311 of the power supply circuit section 300 may be a linear regulator such as an LDO. The same applies to the following embodiments, and duplicated explanations will be omitted.

[0084] Fig. 5 is a schematic circuit diagram of an imaging unit 41 according to one embodiment. In this embodiment, the same or corresponding reference numerals are used for the same components as those in the embodiment described with reference to Figs. 1 to 4, and duplicated explanations are omitted. The same applies to the following embodiments.

[0085] 1 to 4, the power supply circuit section 301 of the imaging unit 41 additionally has a detection section 320 that feeds back the ground potential Gcob of the mounting board 120 via the second flexible board 260 and detects the second ground potential Vgs that appears on the board 62 side by the feedback. As another difference, in addition to the DCDC 311, one end of the detection section 320 is connected between the resistance element 313 and the resistance element 314 in the feedback path.

[0086] Fig. 6 is a schematic circuit diagram of the power supply unit 53 in Fig. 5. The detection section 320 has an OP amplifier 321, four resistive elements 326, 322, 323, and 325, and a transistor 324. In Fig. 6, the resistances of the resistive element 326 and the resistive element 322 are indicated by R1 and R2, respectively.

[0087] The non-inverting input terminal (+) of the OP amplifier 321 is connected to the ground potential Gcob of the mounting board 120 via the ground line 263 of the second flexible substrate 260 and the like, that is, connected to the second ground potential Vgs.

[0088] When a current I1 equal to or greater than normal flows through the imaging unit 41, the second ground potential Vgs is a voltage drop (I1-Ifb)(2r'+r2') [V] when the feedback current I1-Ifb that has passed through the imaging element 100 flows from the ground Gcob of the mounting board 120 through the second flexible board 260 and the like to the ground Gnd of the board 62. When no current I1 flows through the imaging unit 41 or when the current I1 is minute, the second ground potential Vgs is approximately 0.

[0089] An inverting input terminal (−) of the OP amplifier 321 is connected to the output terminal of the OP amplifier 321 via a resistive element 322, and is also connected to one end of a resistive element 326. The other end of the resistive element 326 is connected to the ground potential Gnd of the power supply unit 53. The output terminal of the OP amplifier 321 is also connected to one end of a resistive element 323 that is connected in parallel with the resistive element 322, and the other end of the resistive element 323 is connected to the base of a transistor 324.

[0090] The collector of the transistor 324 is connected between the resistor elements 313 and 314 in the feedback path via a resistor element 325. The emitter of the transistor 324 is connected to the ground potential Gnd.

[0091] When the detection unit 320 detects the second ground potential Vgs by the current I1 flowing through the imaging unit 41, the detection unit 320 generates a flow of a correction current Igc according to the second ground potential Vgs, thereby introducing the second ground potential Vgs into the feedback potential Vfb of the DCDC 311. As a result, the power supply circuit unit 301 according to this embodiment further corrects the first power supply voltage V1 based on the second ground potential Vgs detected by the detection unit 320. The detection unit 320, which includes the OP amplifier 321, the transistor 324, etc., can also be said to be a circuit having a function of sinking, that is, absorbing, a current according to the detected potential.

[0092] More specifically, a conversion coefficient Kvi for converting the second ground potential Vgs into the correction current Igc is set in advance for the detection unit 320, and is defined as Igc=Kvi·Vgs. As described above, the feedback potential Vfb fed back to the DCDC 311 is expressed as Vfb=Ifb·Rfb2. Here, when the correction current Igc flows from between the resistance element 313 and the resistance element 314 in the feedback path toward the detection unit 320, Vfb is Vfb=(Ifb-Igc)Rfb2=(Ifb-Kvi·Vgs)Rfb2. In other words, if the second ground potential Vgs is converted into the correction current Igc, the second ground potential Vgs can also be corrected as the feedback potential Vfb of the DCDC 311.

[0093] The operation of the detection unit 320 will be described in further detail. When the input terminal voltage of the OP amplifier 321 is high impedance (≈∞ [Ω]), the voltage drop at the resistors (r1'', r2'') of the connector harness becomes negligibly small. In this case, Vgs = Gcob [V]. The output terminal voltage of the OP amplifier 321 is defined as Vop = Vgs (1 + R2 / R1).

[0094] When the current I1 does not flow through the imaging unit 41 or the current I1 is very small, the second ground potential Vgs is 0, so the output potential Vop of the OP amplifier 321 is Vop 0 [V]. In this case, the base current ib does not flow through the base of the transistor 324, so the correction current Igc does not flow through the collector of the transistor 324 as a collector current, and Igc = 0 [A]. Therefore, in this case, the power supply circuit section 301 does not correct the first power supply voltage V1 based on the second ground potential Vgs.

[0095] When a current I1 greater than normal flows through the imaging unit 41 and the detection section 320 detects the second ground potential Vgs, the output voltage of the OP amplifier 321 becomes Vop=Vgs(1+R2 / R1), and a base current ib flows through the base of the transistor 324, so that a correction current Igc flows through the collector of the transistor 324 as a collector current. In this case, Igc is defined as Igc=hFE·ib, where hFE is the DC current amplification factor of the transistor 324.

[0096] The imaging unit 41 according to the above embodiment has the same effects as the embodiment described with reference to Figs. 1 to 4. Moreover, according to the imaging unit 41 according to this embodiment, not only the voltage drop I1(2r1+r2) [V] when the current I1 flows from the substrate 62 to the mounting substrate 120 via the second flexible substrate 260 and the like, but also the voltage drop (I1-Ifb)(2r'+r2') [V] when the feedback current I1-Ifb via the imaging element 100 flows from the ground Gcob of the mounting substrate 120 to the ground Gnd of the substrate 62 via the second flexible substrate 260 and the like can be boosted in advance and output.

[0097] 7 is a schematic circuit diagram of an imaging unit 42 according to an embodiment. In this embodiment, the power supply circuit section 302 of the imaging unit 41 additionally includes a differential amplifier circuit 330. The differential amplifier circuit 330 of the power supply circuit section 302 is connected in series with the resistive element 313 and the resistive element 314 in order between the imaging element 100 and the DCDC 311 on the feedback path.

[0098] The differential amplifier circuit 330 has an OP amplifier 331 and four resistor elements 334, 332, 333, and 335. As shown in Fig. 7, the four resistor elements 334, 332, 333, and 335 have the same resistance value R. When the four resistor elements 334, 332, 333, and 335 are configured to have the same resistance value in this manner, the differential amplifier circuit 330 becomes a differential amplifier circuit with a gain of 1.

[0099] An inverting input terminal (-) of the OP amplifier 331 is connected to the ground potential Gcob of the mounting board 120 via the ground line 263 of the second flexible substrate 260, etc., and a resistive element 334. The inverting input terminal (-) of the OP amplifier 331 is also connected to the output terminal of the OP amplifier 331 via a resistive element 335.

[0100] A non-inverting input terminal (+) of the OP amplifier 321 is connected to the input terminal side of the image sensor 100 via a resistive element 332 and the feedback line 262 of the second flexible substrate 260. One end of a resistive element 333 is connected between the non-inverting input terminal (+) of the OP amplifier 321 and the resistive element 332, and the other end of the resistive element 333 is connected to a ground potential Gnd. The output terminal of the OP amplifier 331 is also connected to a resistive element 313 connected in parallel to a resistive element 335.

[0101] In this embodiment, the resistances (r1'', r2'') of the path through which the ground potential Gcob of the mounting board 120 returns in the connector 180 of the mounting board 120, the second flexible board 260, and the connector 182 of the board 62 are equal to the resistances (r1'', r2'') of the path through which the second power supply voltage V1' applied to the image sensor 100 returns. That is, the resistance values ​​of the ground line 263 and the feedback line 262 of the second flexible board 260 are both r2'', and the pins of the connectors 180, 182 connected to the ground line 263 and the feedback line 262, respectively, are both r1''.

[0102] The differential amplifier circuit 330 outputs the difference between the third power supply voltage Vfb appearing on the substrate 62 side due to feedback and the second ground potential as an output voltage Vop to the output terminal. The second ground potential is a voltage that appears on the substrate 62 side due to feedback of the ground potential Gcob of the mounting substrate 120 to the substrate 62 side via the second flexible substrate 260 etc. In FIG. 7, the second ground potential is indicated as (Vfb).

[0103] 7, a feedback current Ifb flows into the non-inverting input terminal (+) of the OP amplifier 331, and a feedback current Ifb' flows into the inverting input terminal (-) of the OP amplifier 331. The potential Vfb of the non-inverting input terminal (+) of the OP amplifier 331, which is connected to the terminal voltage V1' side of the image sensor 100 via the feedback line 262 or the like, is expressed as Vfb=V1'·R / (R+R)=V1' / 2 with respect to the ground potential Gnd. Also, it is expressed as Ifb=V1' / (R+R)=V1' / 2R.

[0104] The output potential Vop of the OP amplifier 331 operates so that the potential of the inverting input terminal (-) of the OP amplifier 331, which is also connected to the output terminal of the OP amplifier 331 via the resistive element 335, becomes Vfb, which is the same potential as the non-inverting input terminal (+). Specifically, the output potential Vop of the OP amplifier 331 operates so that Vop=Vfb+R·Ifb is satisfied, taking into consideration the voltage drop R·Ifb caused by the feedback current Ifb flowing through the resistive element 335. Substituting Vfb=V1' / 2 and Ifb=V1' / 2R into the formula, Vop=V1' is obtained. This indicates that the output voltage Vop of the differential amplifier circuit 330 outputs the terminal voltage V1' of the image sensor 100 on the mounting board 120 as is, based on the ground potential Gnd of the board 62, which is the power supply board.

[0105] That is, the power supply circuit unit 302 does not individually detect the voltage drop in the power supply line 261 etc. of the second flexible substrate 260 and the voltage drop in the ground line 263 etc. of the second flexible substrate 260 caused by the feedback current flowing from the ground potential Gcob of the mounting substrate 120 to the ground potential Gnd of the substrate 62, but reproduces the difference between these voltage drops as is in the output voltage of the differential amplifier circuit 330, that is, directly detects the difference.

[0106] The power supply circuit unit 302 corrects the above-mentioned first power supply voltage V1 based on the above difference output as the output voltage Vop of the differential amplifier circuit 330. That is, the power supply circuit unit 302 corrects the output voltage V1 of the power supply circuit unit 302 by feeding back the terminal voltage V1' of the image sensor 100 to the DCDC 311 as it is.

[0107] The imaging unit 42 according to the above embodiment has the same effects as the embodiment described with reference to Figs. 1 to 4. Moreover, the imaging unit 42 according to this embodiment can eliminate the influence of the contact resistance and transmission resistance of the connector harness and accurately reproduce the terminal voltage V1', which is the distant voltage of the power supply unit 53, based on the ground Gnd of the power supply unit 53. It can also be said that the imaging unit 42 has high accuracy in compensating for the voltage drop in the connector harness.

[0108] Fig. 8 is a schematic circuit diagram of an imaging unit 43 according to one embodiment. This embodiment differs from the embodiment described using Fig. 7 in that the power supply circuit section 303 has a feedback path consisting of a small feedback loop in the power supply unit 53 and a voltage division path between the output terminal of the differential amplifier circuit 330 and the ground Gnd of the substrate 62.

[0109] The feedback path includes a resistor element 313 and a resistor element 314 arranged in series, and feeds back the first power supply voltage V1 output by the power supply circuit unit 303 to the DCDC311 of the power supply circuit unit 303 on the substrate 62. The voltage division path includes resistor elements 336 and 337 connected in series on a path between the output terminal of the differential amplifier circuit 330 and the ground Gnd of the substrate 62.

[0110] As shown in FIG. 8, the resistances of the resistive elements 313 and 314 are Rfb1 and Rfb2, respectively, and the resistances of the resistive elements 336 and 337 are Rfb1' and Rfb2', respectively.

[0111] The resistance ratio Rfb1':Rfb2' between the resistance elements 336 and 337 is the same as the resistance ratio Rfb1:Rfb2 between the resistance elements 313 and 314. Furthermore, there is a short circuit between the resistance elements 313 and 314 and between the resistance elements 336 and 337.

[0112] 7, the differential amplifier circuit 330 outputs the difference between the above-mentioned third power supply voltage Vfb and the second ground potential to the output terminal as the output voltage V1fb. The second ground potential is a voltage that appears on the substrate 62 side by feeding back the ground potential Gcob of the mounting substrate 120 to the substrate 62 side via the second flexible substrate 260 and the like.

[0113] When the current I1 does not flow through the imaging unit 43 or the current I1 is very small, no voltage drop occurs in the second flexible substrate 260 or the like, so the output voltage V1fb of the differential amplifier circuit 330 is V1fb=V1′. In addition, the output potential of the differential amplifier circuit 330 is equal to the feedback potential Vfb′ of the DCDC 311, so the correction current Ifc does not flow from between the resistor elements 313 and 314 to between the resistor elements 336 and 337.

[0114] The output voltage V1 of the power supply circuit unit 303 can be expressed as V1=Ifb·Rfb1+Vfb'. When a current I1 higher than normal flows through the imaging unit 43, a voltage drop occurs in the second flexible substrate 260, etc., and V1fb>V1'. At this time, the electrical balance is lost, and the above-mentioned correction current Ifc flows. As a result, the output voltage V1' after correction of the power supply circuit unit 303 becomes V1'=(Ifc+Ifb)·Rfb1+Vfb'. That is, the output voltage V1' of the DCDC 311 becomes a higher voltage by the amount of the correction current Ifc flowing, and the DCDC 311 has been able to correct and output the voltage drop in the second flexible substrate 260, etc. Note that the DCDC 311 is controlled so that the reference voltages Vref and Vfb' that it constructs are Vref=Vfb'.

[0115] The imaging unit 43 according to the above embodiment has the same effect as the embodiment described using multiple drawings. Moreover, according to the imaging unit 43 according to this embodiment, the terminal voltage V1', which is the distant voltage of the power supply unit 53, is accurately reproduced based on the ground Gnd of the power supply unit 53 by the voltage drop from V1. Since the voltage drop is significantly smaller than the terminal voltage V1', the delay in correcting and tracking the voltage drop according to the increase or decrease in the current value can be suppressed compared to the case of reproducing the terminal voltage V1', and the entire power supply system can be prevented from oscillating.

[0116] Fig. 9 is a graph showing an example of the relationship between the change in current consumption and the change in terminal voltage of the image sensor 100 according to one embodiment. The graph shown in Fig. 9 may show the relationship between the change in current consumption and the change in terminal voltage of the image sensor 100 in the multiple embodiments described with reference to Figs. 1 to 8.

[0117] The horizontal axis of the graph indicates time [s], and the vertical axis indicates the terminal voltage V2 [V] and current consumption [A] of the image sensor 100. In addition, in the graph, the above-mentioned specified upper and lower voltage limits are each indicated by dashed straight lines.

[0118] When a normal current α [A] flows into the imaging element 100, the terminal voltage V1' drops by the amount of voltage drop in the output voltage V1 of the power supply circuit unit due to the contact resistance r1 of the connectors 180, 182 and the transmission resistance r2 of the second flexible substrate 260, that is, by α(2r1+r2) [V] (the voltage after the drop is V1α=V1-α(2r1+r2)). However, the power supply circuit unit of the imaging unit according to each embodiment outputs a voltage corrected for this voltage drop based on the feedback voltage of the terminal voltage V1', so that the terminal voltage V1'=Vsen can be maintained.

[0119] Even when a large current β[A] flows into the image sensor 100, the power supply circuit section of the image sensor according to each embodiment outputs a voltage in which the voltage drop is corrected based on the feedback voltage of the terminal voltage V1′, so that the terminal voltage V1′=Vsen can be maintained. That is, according to the image sensor according to each embodiment, even when the amount of current consumed by the image sensor 100 changes suddenly, the terminal voltage V1′ of the image sensor 100 can be kept within the voltage range Vsen in which the image sensor 100 can operate. That is, it is possible to prevent the occurrence of an overshoot in which the terminal voltage V1′ of the image sensor 100 exceeds the drive capability of the regulator of the power supply circuit section and transiently exceeds the specified upper voltage limit of Vsen, or an undershoot in which the terminal voltage V1′ of the image sensor 100 transiently falls below the specified lower voltage limit of Vsen. That is, the image sensor according to each embodiment can comply with the specified voltage of the image sensor 100, so that stable operation of the image sensor 100 can be ensured.

[0120] In the above embodiments, the imaging unit may have about 10 different power supply circuits, including power supply circuits that should be mounted on a mounting board, such as analog power supply circuits. For example, it is preferable to mount a pixel power supply that supplies power to drive a pixel circuit of an imaging element on the board on which the imaging element is mounted, in order to prevent noise caused by fluctuations in the power supply from affecting the signal given to the pixel system.

[0121] Therefore, in the imaging units according to the embodiments, the arrangement of the first power supply circuit unit and the second power supply circuit unit on the mounting board and the power supply board may be different depending on the type of the power supply circuit. For example, if the power supply circuit is sensitive to noise, a regulator such as an LDO may be arranged on the mounting board to reduce noise contamination. For example, if the power supply circuit is a digital system, a regulator such as a DCDC may be arranged on the power supply board since there is a relatively large margin even if the circuit is affected by noise. Note that when both the first power supply circuit unit and the second power supply circuit unit are mounted on the mounting board of the imaging unit, the power supply board may be considered as an independent component that is not included in the imaging unit.

[0122] In the above embodiments, a camera including a lens unit and a camera body has been described as an example of an imaging device. However, an imaging device does not need to include a lens unit. For example, a camera body is an example of an imaging device. The concept of an imaging device includes not only an imaging device with interchangeable lenses such as a single-lens reflex camera, but also an imaging device with non-interchangeable lenses.

[0123] The imaging unit may also include the ASIC, the power supply unit, etc. Additionally or alternatively, the imaging unit may also include the first flexible board, the second flexible board, etc.

[0124] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0125] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0126] 10 camera, 20 lens unit, 22 optical axis, 30 camera body, 31 housing, 40, 41, 42, 43 imaging unit, 100 imaging element, 101 imaging area, 102 peripheral area, 104 processing circuit, 105 transmission circuit, 110 bonding wire, 120 mounting board, 111 first main surface, 112 second main surface, 121 first layer, 122 second layer, 131 via, 132 insulator, 138 opening, 180, 182, 184 connector, 185 bypass capacitor group, 187 circuit group, 188 capacitor, 201, 211 solder resist layer, 202, 204, 212, 214 wiring layer, 203, 205, 213, 215 insulating layer, 207 Core layer, 210, 220, 230 Adhesive part, 240 Bonding pad, 140 Frame, 141 First surface, 142 Second surface, 143 Third surface, 144 Fourth surface, 145 Fifth surface, 146 Sixth surface, 147 Positioning hole, 148 Mounting hole, 149 Screw, 150 Bracket, 160 Cover glass, 250 First flexible board, 260 Second flexible board, 261 Power line, 262 Feedback line, 263 Ground line, 60 Board unit, 62 Board, 51 MPU, 52 ASIC, 53 Power unit, 88 Display unit, 300, 301, 302, 303 Power circuit unit, 311 DCDC, 312 Coil, 313, 314 Resistance element, 315 Capacitor, 320 Detection unit, 321 OP amplifier, 322, 323, 325, 326 Resistor element, 324 Transistor, 330 Differential amplifier circuit, 331 OP amplifier, 332, 333, 334, 335, 336, 337 Resistor element

Claims

1. a mounting board on which an image sensor for capturing an image of a subject and a connector are mounted; a power supply board having a power supply circuit section including a regulator and a connector mounted thereon; a flexible substrate having one end connected to the connector of the mounting substrate and the other end connected to the connector of the power supply substrate; Equipped with the power supply circuit unit outputs a first power supply voltage, feeds back a second power supply voltage applied to the imaging element via the flexible substrate based on the first power supply voltage, via the flexible substrate, and corrects the first power supply voltage based on a third power supply voltage that appears on the power supply substrate side by the feedback. Imaging unit.

2. the power supply circuit unit feeds back a ground potential of the mounting board via the flexible board, has a detection unit that detects a second ground potential that appears on the power supply board side by the feedback, and further corrects the first power supply voltage based on the detected second ground potential. The imaging unit according to claim 1 .

3. the power supply circuit unit further includes a differential amplifier circuit which outputs to an output terminal a difference between the third power supply voltage and a second ground potential which appears on the power supply board side by feeding back a ground potential of the mounting board via the flexible board, and corrects the first power supply voltage based on the difference. The imaging unit according to claim 1 .

4. a resistance of a path through which a ground potential of the mounting board returns is equal to a resistance of a path through which the second power supply voltage applied to the imaging element returns, in the connector of the mounting board, the flexible board, and the connector of the power supply board; The imaging unit according to claim 3 .

5. The power supply circuit unit includes: a feedback path including a first resistor element and a second resistor element arranged in series, for feeding back the first power supply voltage in the power supply substrate; a voltage division path including a third resistor element and a fourth resistor element connected in series on a path between the output terminal of the differential amplifier circuit and the ground of the power supply board; having a resistance ratio between the third resistive element and the fourth resistive element is equal to a resistance ratio between the first resistive element and the second resistive element; a short circuit is formed between the first resistance element and the second resistance element and between the third resistance element and the fourth resistance element; The imaging unit according to claim 3 or 4.

6. No regulator is provided on the mounting board. The imaging unit according to claim 1 .

7. An imaging device comprising the imaging unit according to claim 1 .

Images