JP2017037996A - Lamination type image sensor and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a technique capable of easily bending an image plane of a lamination type image sensor.SOLUTION: The lamination type image sensor is formed by laminating an imaging chip for taking an image and a processing chip for processing an output signal from the imaging chip. At least part of an image plane of the imaging chip is bendable. The imaging chip and the processing chip are mutually connected at a peripheral part of a pixel region.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a technique for variably controlling the curvature of an imaging surface of an imaging element.

  In recent years, compact digital cameras have been equipped with one or more large image sensors. As a result, it is possible to shoot with ultra-high sensitivity, which was conventionally possible only with a single-lens reflex camera, or with a compact digital camera, such as shooting with a shallow subject depth and vivid blur.

  As described above, when a large image sensor is mounted on a compact digital camera, the lens tends to increase in size, and thus it is necessary to reduce the size of the lens. However, when trying to reduce the size of the lens while maintaining equivalent performance, there is a problem that the incident angle of light incident on the lens from the subject (hereinafter referred to as light incident angle) increases.

  As means for solving such a problem, Patent Document 1 proposes an imaging element having a structure in which an imaging surface is curved in order to correct lens aberration. Japanese Patent Application Laid-Open No. 2004-228561 proposes an imaging apparatus in which the curvature of the imaging surface of the imaging element is set according to the image field aberration of the lens, and the curvature is variably controlled between the tele side and the wide side during zooming. .

Japanese Patent No. 4604307 JP 2012-182194 A

  In order to variably control the curvature of the imaging surface of the imaging element, for example, negative pressure is used. FIG. 8A is a schematic diagram of a configuration of a curvature control mechanism that controls the curvature of the imaging surface of the imaging element.

  As shown in FIG. 8A, the imaging element 800 includes an imaging chip 801 that is a semiconductor substrate having a curved portion 802, a base 803 having a flat portion 804 and an opening 805, a bottom plate 806, and a suction portion 807. The imaging chip 801 is supported by the flat portion 804 on the surface side of the base 803. The bottom plate 806 is provided so as to close the opening 805 on the back surface side of the base 803. The suction part 807 is attached at a position corresponding to the opening 805 in the bottom plate 806.

  The imaging chip 801 has an imaging surface in which a plurality of pixels are two-dimensionally arranged in the central portion, and has a circuit portion in the peripheral portion.

  Then, the suction unit 807 sucks the gas inside the opening 805 made airtight by the bottom plate 806 and variably controls the curvature of the bending part 802 by controlling the atmospheric pressure (negative pressure) inside the opening 805. Is configured to do.

  Recently, as an image sensor used in a digital camera, a laminated image sensor in which an imaging chip made of an imaging LSI (integrated circuit) is stacked on a signal processing chip made of a signal processing LSI (integrated circuit) has appeared. ing. In the stacked image sensor, one TSV (Through Silicon Via) is provided for each pixel or a plurality of pixels, and a pixel signal can be sent to a signal processing chip via a micro bump. As described above, by forming the imaging chip and the signal processing chip in a stacked structure, it is possible to realize space saving, high-speed processing, and the like.

  Here, as shown in FIG. 8B, the stacked image sensor in which the imaging chip 801 and the signal processing chip 810 are fixed in a superposed state has a thickness larger than that of a normal image sensor. Is expected to be difficult.

  The present invention has been made in view of the above problems, and an object thereof is to realize a technique capable of easily bending the imaging surface of a multilayer image sensor.

  In order to solve the above problems and achieve the object, a multilayer image sensor of the present invention is a multilayer image sensor in which an imaging chip for capturing an image and a processing chip for processing an output signal from the imaging chip are stacked. In this case, at least a part of the imaging surface of the imaging chip can be bent and deformed, and the imaging chip and the processing chip are connected to each other at a peripheral portion of the pixel region.

  According to the present invention, the imaging surface of the multilayer image sensor can be easily curved.

1 is a block diagram illustrating a configuration of an imaging apparatus according to an embodiment. 1 is a configuration diagram of a stacked image sensor of the present embodiment. The circuit diagram of the imaging chip and processing chip of this embodiment. The perspective view (a) which shows a mode that the image pick-up chip and processing chip of the lamination type image sensor of this embodiment are piled up and fixed, a side view (b) of a state piled up and fixed, and a front view (c) . The figure explaining the structure of a laminated image sensor and a curvature control part. The figure which shows the curvature control table used for the curvature control process of this embodiment. 6 is a flowchart showing curvature control processing of the imaging surface of the imaging device according to the present embodiment. The figure explaining the structure of the conventional curvature control part.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention with reference to an accompanying drawing is demonstrated in detail. The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment. Moreover, you may comprise combining suitably one part of each embodiment mentioned later.

  Hereinafter, embodiments in which the present invention is applied to an imaging apparatus such as a compact digital camera will be described. The present invention can also be applied to other devices having a function capable of variably controlling the curvature of the imaging surface of the image sensor.

  <Apparatus Configuration> With reference to FIG. 1, an outline of a configuration and functions of an imaging apparatus according to an embodiment of the present invention will be described.

  In FIG. 1, an image pickup apparatus 100 according to the present embodiment is equipped with a one-type or larger large image pickup element.

  The optical system 101 includes a focus lens, a zoom lens, a diaphragm, a shutter, and the like.

  The optical system control unit 102 performs drive control of the lens, the diaphragm, and the shutter based on a control signal from the main control unit 111. For example, during zooming, the optical system control unit 102 performs zoom control to move the zoom lens to a position corresponding to a predetermined zoom magnification between the tele end and the wide end in accordance with the zoom operation of the user. The shutter is a mechanical shutter that is mechanically driven to adjust the irradiation time of subject image light formed on the imaging surface of the multilayer image sensor 103. The diaphragm adjusts the amount of light of the subject image formed on the imaging surface of the multilayer image sensor 103, and includes diaphragm blades whose aperture diameter is variable by being mechanically driven.

  A stacked image sensor (hereinafter also referred to as a sensor chip) 103 is fixed in a state where an imaging chip 300 that is a first semiconductor substrate made of a CCD, a CMOS, or the like and a processing chip 310 that is a second semiconductor substrate are overlapped. Configured. The imaging chip 300 is configured by two-dimensionally arranging pixels 200 that convert a subject image formed through the optical system 101 into an electrical signal.

  The processing chip 310 has an AD conversion circuit 210 that converts an analog signal into a digital signal for the pixels 200 of the imaging chip 300, and an image that performs predetermined signal processing or the like on the digital signal generated by the AD conversion circuit 210. And processing circuit 220.

  The detailed configuration of the sensor chip 103 will be described later with reference to FIGS.

  The signal processing unit 106 includes a digital signal processing device (DSP). The signal processing unit 106 performs signal processing such as color conversion processing and gamma correction processing on the digital signal output from the sensor chip 103, and performs compression processing to convert image data. Generate. The signal processing unit 106 outputs image data to the memory unit 107 and the recording medium 109 according to a control signal from the main control unit 111, and performs predetermined signal processing on the image data read from the memory unit 107 and the recording medium 109. Apply. Further, the signal processing unit 106 has a function of detecting photometric data such as a focused state and an exposure amount from the output signal of the sensor chip 103.

  The imaging control unit 104 generates a timing signal for driving the sensor chip 103 based on a control signal from the main control unit 111 and outputs the timing signal to the imaging chip 300 and the processing chip 310 of the sensor chip 103.

  As will be described later with reference to FIG. 5, the curvature control unit 105 is provided in the sensor chip 103, and performs variable control of the curvature of the imaging surface of the sensor chip 103 based on a control signal from the main control unit 111.

  The main control unit 111 includes a CPU, a main memory (RAM), an input / output circuit, a timer circuit, and the like, and the CPU expands the program stored in the memory unit 107 in the RAM work area and executes the program. Control overall operation.

  The memory unit 107 temporarily stores the image data output from the signal processing unit 106. The memory unit 107 stores constants, programs, setting information, and the like for operation of the CPU of the main control unit 111. Here, the program is a program for executing a variable control sequence of the curvature of the imaging surface of the imaging device described later in the present embodiment.

  The display unit 108 uses, for example, an LCD or an organic EL, and displays an image, a display for assisting operations, a camera status display, and a shooting screen and a distance measurement area during shooting.

  The recording medium 109 records image data (still images and moving images) output from the signal processing unit 106. The recording medium 109 may be a memory card or a hard disk drive attached to the imaging apparatus 100. Alternatively, a flash memory or a hard disk drive built in the imaging apparatus 100 may be used, and the memory unit 107 and the recording medium 109 may have the same configuration.

  The operation unit 110 is an operation unit that receives a user operation for inputting various instructions to the imaging apparatus 100, and various forms such as a physical operation member such as a button or a switch or an input unit through a touch panel can be used. It is. The operation unit 110 includes, for example, a menu switch for performing various settings at the time of image shooting and playback, a zoom lever for instructing a zoom operation of a lens, an operation mode switching switch such as a shooting mode and a playback mode, a shutter switch, and a power switch. Etc. The main control unit 111 controls the imaging apparatus 100 based on an instruction or setting input by the user via the operation unit 110 and displays setting information, an operation state, an image, and the like on the display unit 108.

  <Configuration of Multilayer Image Sensor> Next, the configuration of the multilayer image sensor of this embodiment will be described with reference to FIGS.

  FIG. 2 illustrates a schematic configuration of the imaging chip 300 and the processing chip 310 that constitute the stacked image sensor of the present embodiment.

  In FIG. 2, the stacked image sensor 103 includes an imaging chip 300 in which pixels 200 are two-dimensionally arranged, and a processing chip 310 in which a necessary number of AD conversion circuits 210 are provided for each vertical pixel group. Further, the processing chip 310 includes an image processing circuit 220 in which each AD conversion circuit 210 is connected to the horizontal signal line 311. The imaging chip 300 and the processing chip 310 are fixed in a superposed state so that the respective micropads 303 and 312 are electrically connected via the micro bumps 320 as shown in FIG.

  Here, the configuration of the imaging chip 300 will be described.

  In the imaging chip 300, a plurality of millions of pixels 200 are two-dimensionally arranged to form a pixel group, but in FIG. 2, only 6 pixels in the horizontal direction and only 3 pixels in the vertical direction are shown in FIG. Is shown.

  In the present embodiment, the vertical signal line 301 is provided for each column so that the pixels 200 in the same column in the vertical direction share one AD conversion circuit 210.

  Each pixel 200 is provided with a selection signal line 302 for turning on the selection transistor 205 (see FIG. 3). The signal of the pixel 200 in each column is sequentially output from the shared vertical signal line 301 by the selection signal line 302.

  The vertical signal line 301 is connected to the micropad 303 and outputs a pixel signal to the processing chip 310 via the microbump 320.

  In FIG. 2, the vertical signal lines 301 are distributed so as to be provided on the upper side and the lower side of the imaging chip 300 so that the micropads 303 are provided. However, the positions of the micropads 303 are not limited to this, and other wirings are provided. It may be a layout.

  Next, the configuration of the processing chip 310 will be described.

  The processing chip 310 is provided with an AD conversion circuit 210 for each vertical signal line 301 of the imaging chip 300. Each AD conversion circuit 210 is connected to the micropad 303 of the vertical signal line 301 of the imaging chip 300 via the micropad 312 and the microbump 320, and receives a pixel signal from the imaging chip 300. Each AD conversion circuit 210 is connected to the image processing circuit 220 through a horizontal signal line 311, and an image signal output from the AD conversion circuit 210 is input to the image processing circuit 220 through the horizontal signal line 311.

  3 illustrates a circuit configuration of one pixel 200 of the imaging chip 300 and the AD conversion circuit 210 of the processing chip 310 illustrated in FIG.

  The pixel 200 includes four transistor circuits including a photodiode 201, a transfer transistor 202, a reset transistor 203, an amplification transistor 204, and a selection transistor 205. As these transistors 202 to 205, for example, N-channel MOS transistors are used.

  The photodiode 201 photoelectrically converts the received light into photoelectric charges (here, electrons) having a charge amount corresponding to the amount of light.

  The cathode of the photodiode 201 is electrically connected to the gate of the amplification transistor 204 through the transfer transistor 202. A node 206 electrically connected to the gate of the amplification transistor 204 is called an FD (floating diffusion) portion.

  The transfer transistor 202 is connected between the cathode of the photodiode 201 and the FD unit 206. Then, a transfer pulse φTRS is applied to the gate of the transfer transistor 202 via a transfer line (not shown), and the photoelectric charge photoelectrically converted by the photodiode 201 is transferred to the FD unit 206.

  The reset transistor 203 has a drain connected to the pixel power supply Vdd and a source connected to the FD unit 206. Then, when the reset pulse φRST is applied to the gate of the reset transistor 203 via a reset line (not shown), the reset transistor 203 is turned on. The reset transistor 203 resets the FD unit 206 by transferring the charge of the FD unit 206 to the pixel power supply Vdd prior to the transfer of the signal charge from the photodiode 201 to the FD unit 206.

  The amplification transistor 204 has a gate connected to the FD unit 206 and a drain connected to the pixel power supply Vdd. The amplification transistor 204 outputs the potential of the FD unit 206 after being reset by the reset transistor 203 as a reset level, and further outputs the potential of the FD unit 206 after transferring the signal charge by the transfer transistor 202 as a signal level. .

  For example, the selection transistor 205 has a drain connected to the source of the amplification transistor 204 and a source connected to the output signal line 207. Then, when a selection pulse φSEL is applied to the gate of the selection transistor 205 via a selection line (not shown), the selection transistor 205 is turned on, and the signal output from the amplification transistor 204 is set to the output signal line 207 with the photodiode 201 selected. Relay.

  Note that the selection transistor 205 may have a circuit configuration connected between the pixel power supply Vdd and the drain of the amplification transistor 204.

  Further, as illustrated in FIG. 3, the pixel 200 is not limited to the one configured with four transistors, and may be configured with, for example, three transistors that serve both as the amplification transistor 204 and the selection transistor 205.

  A pixel signal output from the pixel 200 via the output signal line 207 is transferred to the AD conversion circuit 210. The AD conversion circuit 210 includes a comparator 211, an up / down counter (U / D CNT) 212, a memory 213, and a DA converter (DAC) 214.

  In the comparator 211, the output signal line 207 is connected to one of a pair of input terminals, and the DAC 214 is connected to the other. The DAC 214 outputs a ramp signal whose level changes like a ramp in accordance with a control signal from the imaging control unit 104.

  The comparator 211 compares the level of the ramp signal input from the DAC 214 with the level of the pixel signal input from the output signal line 207. For example, the comparator 211 outputs a high level comparison signal when the pixel signal level is lower than the ramp signal level, and outputs a low level comparison signal when the pixel signal level is higher than the ramp signal level. Output.

  The up / down counter 212 is connected to the output terminal of the comparator 211 and counts, for example, a period during which the comparison signal is at a high level or a period during which the comparison signal is at a low level. By this counting process, the output signal of each pixel 200 is converted into a complete digital signal value.

  An AND circuit may be provided between the comparator 211 and the up / down counter 212, a pulse signal may be input to the AND circuit, and the number of pulse signals may be counted by the up / down counter 212.

  The memory 213 is connected to the up / down counter 212 and stores the count value counted by the up / down counter 212.

  The AD conversion circuit 210 counts the count value corresponding to the reset level based on the pixel signal when the pixel 200 is reset, and counts the count value based on the pixel signal after a predetermined imaging time. May be stored in the memory 213.

  The pixel signal stored in the memory 213 is transferred to the image processing circuit 220, subjected to image processing such as defect correction as a digital image signal together with other pixel signals, and is output to the signal processing unit 106.

  FIG. 4A is a perspective view illustrating a state in which the imaging chip 300 and the processing chip 310 of the stacked image sensor 103 according to the present embodiment are overlapped and fixed. 4B and 4C are a side view and a front view showing a state in which the imaging chip 300 and the processing chip 310 of the multilayer image sensor 103 according to the present embodiment are overlapped and fixed.

  In the multilayer image sensor 103 of the present embodiment, the upper surface of the imaging chip 300 is used as a light receiving unit, the micropad 303 is provided on the lower surface of the imaging chip 300, and the micropad 312 is provided on the upper surface of the processing chip 310. , 312 are overlapped and fixed so as to be connected via the micro bump 320.

  In the present embodiment, the AD conversion circuit 210 is shared for each vertical signal line 301 of the imaging chip 300 as shown in FIG. For this reason, the micropad 303 is formed not only at the position corresponding to the pixel region 400 of the light receiving unit of the imaging chip 300 but only at the peripheral portion of the pixel region 400.

  As shown in the figure, an imaging chip 300 that is a first semiconductor substrate has a pixel region 400 of a light receiving unit in which pixels 200 are two-dimensionally arranged in a central portion, and has a rectangular shape having a circuit portion in a peripheral portion. There is a micropad 303 on the periphery of the back surface.

  The processing chip 310 which is the second semiconductor substrate is provided with a micropad 312 at a position corresponding to the micropad 303 of the first semiconductor substrate. The processing chip 310 has a hollow shape 410 in which a part of the region other than the region where the micropad 312 is provided is removed. The hollow shape 410 is a portion other than the peripheral portion connected to the imaging chip 300 in the processing chip 310 and is provided at a position including the pixel region 400 of the imaging chip 300.

  Such a hollow shape 410 is useful for curving the imaging chip 300 with high accuracy when the sensor chip 103 is curved as will be described later with reference to FIG. 5 and for avoiding risks such as destruction due to the thickness of the chip. Thus, there is an effect of maintaining the flexibility of the entire chip.

  In FIG. 5, the processing chip 310 has a shape in which a portion corresponding to the pixel region 400 of the imaging chip 300 is hollowed out, but a portion other than the region where the micropad 312 needs to be provided is partially removed, and the same effect is obtained. Other shapes may be used as long as they are obtained.

  In a state where the back surface of the imaging chip 300 and the front surface of the processing chip 310 are overlapped, the micro pad 303 disposed on the back surface of the imaging chip and the micro pad 312 disposed on the front surface of the processing chip 310 form the micro bump 320. Electrically connected. The imaging chip 300 and the processing chip 310 are firmly fixed so that electrical characteristics can be maintained.

  <Curvature Control Unit> Next, the configuration and function of the curvature control unit 105 of this embodiment will be described with reference to FIG.

  As shown in FIG. 5, the stacked image sensor 103 includes an imaging chip 300 having a curved portion 501 at a central portion, a processing chip 310 having a hollow shape 410 at a central portion, a pedestal having a flat portion 504 and an opening 505. 503, a bottom plate 506, and a suction unit 507. The sensor chip 103 has the light receiving part of the imaging chip 300 on the upper surface side and the hollow shape 410 of the processing chip 310 on the lower surface side, and the flat part 103a at the peripheral part thereof is fixed to the flat part 504 of the base 503 with an adhesive. The bottom plate 506 is provided so as to close the opening 505 on the back surface side of the pedestal 503. The suction unit 507 is attached to a position corresponding to the opening 505 in the bottom plate 506.

  The central portion of the bending portion 501 can be bent three-dimensionally (can be bent and deformed) in an arc shape toward the opening 505 side of the base 503.

  Then, the suction unit 507 sucks the gas inside the opening 505 that is made airtight by the bottom plate 506, and controls the pressure (negative pressure) inside the opening 505 to variably control the curvature of the bending part 501. Is configured to do.

  The dotted lines in the figure illustrate the state where the imaging chip 300 and the processing chip 310 of the sensor chip 103 are curved to a predetermined curvature by the suction unit 507.

  Here, it is obvious that the thickness of the sensor chip 103 in which the two substrates are stacked is increased as compared with an imaging element in which the substrates are not stacked (an AD conversion circuit or the like is disposed in the peripheral portion of the pixel region).

  In this embodiment, the hollow shape 410 is formed in the processing chip 310 in the sensor chip 103 to change the area of the portion overlapping the imaging chip 300, thereby reducing the connection portion between the chips. By adopting such a configuration, it is possible to maintain flexibility when bending the stacked chips, and it is possible to realize a function of changing the curvature of the imaging surface while maintaining the advantage of the stacked type.

  In addition, as a method of changing the curvature of the imaging surface of the imaging chip 300, in addition to the method using the negative pressure as described above, a method using a piezoelectric element, or a magnetic film is formed on the back side of the sensor chip 103, A method of making the curvature variable by controlling the magnetic force generated by the magnet or the electromagnetic coil is applicable.

  <Curvature Control Table> Next, a curvature control table used for curvature control of the imaging surface of the multilayer image sensor 103 of this embodiment will be described with reference to FIG.

  6A shows a curvature control table in which the zoom position of the zoom lens is associated with the curvature control value C used for curvature control of the imaging surface of the sensor chip 103, and FIG. 6B shows the bending portion 501 of the imaging chip 300. The relationship between the curvature control value C, the zoom position, and the curved shape is shown. The memory unit 107 of the imaging apparatus 100 according to the present embodiment stores a curvature control table as illustrated in FIG. The curvature control unit 105 uses the curvature control value C to control the imaging surface of the sensor chip 103 to have a curvature corresponding to the zoom position of the zoom lens. The curvature control value C set in the curvature control table is obtained by conducting an experiment or the like in advance on the sensor chip 103 so as to obtain an appropriate curvature for each zoom position.

  In the example shown in FIG. 6B, the curvature decreases as the zoom position approaches the tele side (the shape of the bending portion 501 approaches flat), and the curvature increases as the zoom position approaches the wide side (the curvature of the bending portion 501 increases). The curvature control value C is set so as to increase. Note that the zoom lens of the present embodiment is configured such that the light incident angle on the imaging surface of the sensor chip 103 increases as the zoom position is closer to the wide side during image capture or live view.

  In the curvature control table of FIG. 6A, zoom points such as Wide and M1 are used as zoom positions, but the focal length at each zoom position may be used.

  By using such a curvature control table, the curvature of the imaging surface of the sensor chip 103 is controlled so that the imaging characteristics are optimally maintained with respect to the light beam incident angle of the zoom lens that changes according to the zoom position during zooming. be able to.

  <Variable Control of Curvature of Imaging Surface of Imaging Device> Next, a variable control sequence of the curvature of the imaging surface of the stacked image sensor 103 by the imaging apparatus 100 of the present embodiment will be described with reference to FIG.

  7 is started when the imaging apparatus 100 is in the shooting mode, and the main control unit 111 and the curvature control unit 105 are executed in cooperation. Note that the CPU of the main control unit 111 implements the processing of FIG. 7 by developing the program read from the memory unit 107 in the main memory and executing it.

  When a shooting operation start instruction is input via the operation unit 110, the main control unit 111 performs initial setting of various conditions such as control parameters related to the shooting sequence in step S701.

  In step S <b> 702, the main control unit 111 acquires information related to the zoom position of the zoom lens set by operating the zoom lever or the like of the operation unit 110.

  In step S703, the main control unit 111 generates a control value C for setting the curvature corresponding to the zoom position information acquired in step S702 with reference to the curvature control table of FIG. Part 105.

  In step S704, the curvature control unit 105 performs negative pressure control of the suction unit 507 based on the control value C given in step S703. Then, the bending portion 501 of the imaging chip 300 in the sensor chip 103 is bent and deformed, and control is performed so as to obtain a desired curvature.

  In step S <b> 705, the main control unit 111 determines whether an imaging end instruction has been input via the operation unit 110. If input, the main control unit 111 ends the process. If not input, the process returns to step S702, and curvature control according to the acquired zoom position information is repeatedly executed.

  As described above, according to the present embodiment, the hollow shape 410 is formed in the processing chip 310 in the sensor chip 103, so that flexibility when the sensor chip 103 is curved is maintained, and the imaging surface of the imaging chip 300 is maintained. Curvature can be controlled with high accuracy.

[Other Embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  In the present embodiment, the structure in which the imaging chip 300 and the processing chip 310 are stacked is illustrated. However, the present invention is not limited to this, and other semiconductor integrated circuit chips in which signals are input and output are stacked. The present invention can also be applied to the case of configuring the above.

DESCRIPTION OF SYMBOLS 100 ... Imaging device 101 ... Optical system 103 ... Laminated image sensor 105 ... Curvature control part 106 ... Signal processing part 111 ... Main control part 300 ... Imaging chip, 310 ... Processing chip

Claims (8)

A stacked image sensor in which an imaging chip for capturing an image and a processing chip for processing an output signal from the imaging chip are stacked,
At least a part of an imaging surface of the imaging chip can be bent and deformed, and the imaging chip and the processing chip are connected to each other at a peripheral portion of a pixel region.   The stacked image sensor according to claim 1, wherein the processing chip is partially removed except for a peripheral portion connected to the imaging chip.   3. The stacked image sensor according to claim 2, wherein a portion other than the peripheral portion of the processing chip is formed in a hollow shape, and an area of a portion overlapping the imaging chip is made different.   The multilayer image sensor according to claim 3, wherein the hollow shape is provided at a position including a pixel region in the imaging chip. In the imaging chip, a plurality of pixels are arranged two-dimensionally,
5. The stacked image sensor according to claim 1, wherein a circuit portion for processing an output signal of a pixel of the imaging chip is provided in the peripheral portion of the processing chip. .   6. The multilayer image sensor according to claim 1, further comprising a curvature control unit configured to bend and deform the multilayer image sensor and control a curvature of an imaging surface of the image sensor. . The stacked image sensor according to any one of claims 1 to 6,
An image pickup apparatus comprising: control means for variably controlling the curvature of the image pickup surface of the image sensor during zooming. Zoom means for performing a zoom operation in response to a user operation;
The imaging apparatus according to claim 7, wherein the control unit variably controls a curvature of an imaging surface of the image sensor according to a zoom position.

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