Imaging element and imaging device

Abstract

This imaging element comprises: pixels that include a photoelectric conversion unit for converting light into an electric charge and that output a signal based on the electric charge converted by the photoelectric conversion unit; a processing unit that processes the signals output from the pixels; a holding unit that holds a setting value for controlling at least either one of the pixels and the processing unit; and an updating unit that updates the setting value held by the holding unit on the basis of an input of an update request signal for requesting an update of the setting value.

Description

Image sensor and image pickup device

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

[0002] Settings relating to the operation of the image sensor may need to be changed while the image sensor is in operation, and it is desirable to be able to change (update) each setting at an appropriate timing (see, for example, Japanese Patent Application Laid-Open No. 2003-144998).

[0003] JP 2010-004146

[0004] According to a first aspect of the disclosure, the imaging element includes a photoelectric conversion unit that converts light into an electric charge, and is equipped with pixels that output signals based on the electric charges converted by the photoelectric conversion unit, a processing unit that processes the signals output from the pixels, a holding unit that holds setting values ​​for controlling at least one of the pixels and the processing unit, and an update unit that updates the setting values ​​held by the holding unit based on input of an update request signal to request an update of the setting values.

[0005] According to a second aspect of the disclosure, the imaging element includes a photoelectric conversion unit that converts light into electric charges, and includes pixels that output signals based on the electric charges converted by the photoelectric conversion unit, a processing unit that processes the signals output from the pixels, a holding unit that holds a first setting value for controlling at least one of the pixels and the processing unit, an update permission unit that outputs an update permission signal when a vertical synchronization signal and a predetermined signal are input, and an update unit that holds a second setting value and, when the update permission signal is input, updates the first setting value held by the holding unit with the second setting value.

[0006] According to a third aspect of the disclosure, the imaging element includes a photoelectric conversion unit that converts light into an electric charge, and includes pixels that output signals based on the electric charges converted by the photoelectric conversion unit, a processing unit that processes the signals output from the pixels, a holding unit that holds a first setting value for controlling the pixels and a second setting value for controlling the processing unit, and an update unit that updates the first setting value held in the holding unit when the second setting value is input after the first setting value is input.

[0007] According to a fourth aspect of the disclosure, an imaging device includes an imaging element, and a transmitting unit that, when updating a setting value of a control parameter held by the imaging element for controlling the operation of the imaging element to a new setting value, transmits the new setting value and then transmits an update request signal to the imaging element requesting an update to the new setting value.

[0008] According to a fifth aspect of the disclosure, an imaging device includes the imaging element, and a transmitting unit that, when updating a setting value held by the imaging element for controlling the operation of the imaging element to a new setting value, transmits the new setting value and then transmits an update request signal to the imaging element requesting an update to the new setting value.

[0009] The configurations of the embodiments described below may be modified as appropriate, and at least a portion of the configuration may be replaced with other components. Furthermore, components that are not particularly limited in terms of their placement may be placed in any position that can achieve their function, not limited to the placement disclosed in the embodiments.

[0010] FIG. 1 is a diagram schematically illustrating an example of the configuration of a digital camera including an image sensor according to a first embodiment. FIG. 2 is a diagram illustrating a schematic configuration of a pixel in the image sensor according to the first embodiment. FIG. 3A is a circuit diagram illustrating the configuration of a register unit, and FIG. 3B is a timing chart illustrating the operation of an update permission unit. FIG. 4A is a circuit diagram illustrating the configuration of a register unit according to a comparative example, and FIG. 4B is a timing chart illustrating the operation of the update permission unit according to the comparative example. FIG. 5 is a timing chart illustrating the case where the setting values ​​of settings A, B, and C are updated in an image sensor including a register unit according to a comparative example. FIG. 6 is a timing chart illustrating another example where the setting values ​​of settings A, B, and C are updated in an image sensor including a register unit according to a comparative example. FIG. 7 is a timing chart illustrating the case where the setting values ​​of settings A, B, and C are updated in an image sensor including a register unit according to the first embodiment. FIG. 8 is a diagram illustrating the configuration of an image sensor according to a second embodiment. Fig. 9(A) is a circuit diagram showing the configuration of a first register unit, Fig. 9(B) is a circuit diagram showing the configuration of a second register unit, and Fig. 9(C) is a timing chart for explaining the operation of a second update permission unit. Fig. 10 is a timing chart for explaining a case where an exposure time setting and a gain setting are changed in an image sensor including a register unit according to the comparative example shown in Fig. 4(A). Fig. 11 is a timing chart for explaining another example where an exposure time setting and a gain setting are changed in an image sensor including a register unit according to the comparative example. Fig. 12 is a timing chart for explaining a case where an exposure time setting and a gain setting are changed in an image sensor according to the second embodiment.

[0011] First Embodiment A digital camera 1 (hereinafter referred to as camera 1) equipped with an image sensor 21 according to a first embodiment will be described below with reference to FIGS. 1 to 7. Note that an XYZ Cartesian coordinate system is provided in the drawings below as appropriate to facilitate explanation and understanding. In this coordinate system, the direction from the subject toward the camera body 2 when the photographer is in a camera position (hereinafter referred to as the normal position) in which the optical axis OA is horizontal and the photographer is taking a landscape image is defined as the +Z direction. Also, the direction toward the right as viewed from the camera body 2 in the normal position is defined as the +X direction. Also, the direction toward the top in the normal position is defined as the +Y direction. Note that the scales of the shapes, lengths, thicknesses, and the like of the various parts shown in the embodiments do not necessarily correspond to the actual objects, and some elements may be omitted from the drawings to facilitate understanding.

[0012] 1 is a diagram schematically illustrating an example configuration of a camera 1 equipped with an image sensor 21 according to the first embodiment. The camera 1 includes an interchangeable lens 3 and a camera body 2. The interchangeable lens 3 is attached to the camera body 2 via a lens mount (not shown). Note that the camera 1 may also be configured as an integrated lens camera rather than an interchangeable lens camera.

[0013] The interchangeable lens 3 includes an imaging optical system 31 including, for example, a zoom lens, a focus lens, an aperture, an anti-vibration lens, etc., and a lens control unit 32. The lens control unit 32 includes a CPU (Central Processing Unit) and peripheral components such as memory. The lens control unit 32 performs drive control of the focus lens and aperture, detects the positions of the zoom lens and focus lens, sends lens information to the camera body 2, and receives camera information from the camera body 2.

[0014] The camera body 2 includes, for example, an image sensor 21 , an image processing unit 22 , a body control unit 23 , a display unit 24 , an operation unit 25 , and a recording unit 26 .

[0015] The operation unit 25 includes a shutter button, operation members for various settings, etc. The display unit 24 is, for example, a liquid crystal monitor (also called a rear monitor) mounted on the rear surface of the camera body 2.

[0016] The body control unit 23 includes a CPU and peripheral components such as memory. The body control unit 23 controls the operation of the camera 1, such as driving and controlling the image sensor 21, reading pixel signals from the image sensor 21, performing focus detection calculations and focusing the interchangeable lens 3, and displaying and recording image data. The body control unit 23 also communicates with the lens control unit 32, receiving lens information and transmitting camera information (such as defocus amount and aperture value).

[0017] The body control unit 23 also includes a timing generation unit 231 and a communication unit 232. The timing generation unit 231 outputs a synchronization signal to the drive control unit 43 included in the image sensor 21. When changing the settings of the image sensor 21, the communication unit 232 transmits new setting values ​​for control parameters used to control the operation of the image sensor 21 to the image sensor 21. After transmitting the new setting values ​​for the control parameters, the communication unit 232 also transmits an update request signal to the image sensor 21 requesting that the control parameters be updated to the new setting values.

[0018] The recording unit 26 has a card slot into which a storage medium such as a memory card can be inserted. The recording unit 26 stores the image data and various data generated by the image processing unit 22 in the storage medium inserted in the card slot. The recording unit 26 has an internal memory. In this case, the recording unit 26 can also record the image data and various data generated by the image processing unit 22 in the internal memory.

[0019] The image processing unit 22 is an image processing engine that performs various image processes on the pixel data input from the image sensor 21 .

[0020] The image sensor 21 is disposed at the intended image formation plane (intended focal plane) of the interchangeable lens 3 and photoelectrically converts the subject image formed by the interchangeable lens 3 .

[0021] 2 is a diagram illustrating a schematic configuration of the image sensor 21 according to the first embodiment. The image sensor 21 includes a pixel array 50 including a plurality of pixels 51 arranged in a matrix of N rows and M columns (M and N are each an arbitrary integer), a vertical drive unit 42, a drive control unit 43, a horizontal drive unit 44, a signal processing unit 45, a memory unit 46, and a register unit 47.

[0022] The pixels 51 are assigned one of four pixels, namely, green pixels Gb, Gr, blue pixels B, and red pixels R, according to, for example, a Bayer array. Each pixel 51 includes a photoelectric conversion unit that converts light into electric charges, and outputs a signal based on the electric charges converted by the photoelectric conversion unit.

[0023] Based on the synchronization signal input from the timing generation unit 231 of the body control unit 23, the drive control unit 43 generates clock signals and control signals that serve as the basis for the operation of the vertical drive unit 42, signal processing unit 45, memory unit 46, horizontal drive unit 44, and register unit 47, and provides these signals to the vertical drive unit 42, signal processing unit 45, memory unit 46, horizontal drive unit 44, and register unit 47, etc.

[0024] The vertical drive unit 42 supplies control signals such as signal RES(n) (where n is an integer from 1 to N), signal TX(n), and signal SEL(n) to M pixels 51 in the nth row, thereby controlling the operation of each pixel 51.

[0025] The signal processing unit 45 includes analog-to-digital conversion units (ADC) 451(1) to 451(M), correlated double sampling units (CDS) 452(1) to 452(M), and amplifiers 453(1) to 453(M).

[0026] The ADCs 451(1) to 451(M) convert the noise signals and photoelectric conversion signals input via the vertical signal lines 52(1) to 52(M) into digital signals and output them to the CDSs 452(1) to 452(M), respectively.

[0027] The CDSs 452(1) to 452(M) perform correlated double sampling on the input digital signals, remove noise from the digital signals, and output the noise-removed digital signals to the amplifiers 453(1) to 453(M), respectively.

[0028] The amplifiers 453(1) to 453(M) amplify the input digital signals according to the gain and output the amplified signals to the memory unit 46.

[0029] The memory unit 46 includes memories 461(1) to 461(M). The memories 461(1) to 461(M) store the signals output from the amplifiers 453(1) to 453(M), respectively.

[0030] The horizontal drive unit 44 outputs the signals stored in the memories 461 ( 1 ) to 461 (M) to the image processing unit 22 in response to the scanning signal from the drive control unit 43 .

[0031] The register unit 47 manages the setting values ​​of various control parameters used to control the vertical drive unit 42, the horizontal drive unit 44, the signal processing unit 45, the memory unit 46, and the like. Examples of control parameters include, but are not limited to, exposure time and gain. The register unit 47 includes a first register 471, a second register 472, and an update permission unit 473. The first register 471 stores the setting values ​​of various control parameters used to control the vertical drive unit 42, the horizontal drive unit 44, the signal processing unit 45, the memory unit 46, and the like. The second register 472 temporarily stores new setting values ​​for the various control parameters. The update permission unit 473 outputs an update permission signal that permits updating the setting values ​​stored in the first register 471 to new setting values ​​stored in the second register 472. The new setting values ​​for the various control parameters are input to the register unit 47 from the communication unit 232 of the body control unit 23. A register unit 47 is provided for each control parameter.

[0032] 3A is a circuit diagram showing the configuration of the register unit 47. A new setting value is input to the second register 472 from the communication unit 232 of the body control unit 23. A clock signal is also input to the second register 472 from an external source. The second register 472 temporarily stores the new setting value input from the communication unit 232. The second register 472 outputs the new setting value input from the communication unit 232 to the first register 471 in synchronization with the clock signal.

[0033] The first register 471 receives a new setting value from the second register 472, an update permission signal from the update permission unit 473, and an external clock signal. When the update permission signal is received from the update permission unit 473, the first register 471 synchronizes with the clock signal (more specifically, the vertical synchronization signal) and updates the currently held setting value to the new setting value received from the second register 472. That is, in this embodiment, the first register 471 and the update permission unit 473 function as an update unit that updates the setting value held in the first register 471 when an update request signal is received.

[0034] The update permission unit 473 is, for example, an AND circuit. The update permission unit 473 receives a vertical synchronization signal from the drive control unit 43 and an update request signal from the communication unit 232 of the body control unit 23. When the update permission unit 473 receives the vertical synchronization signal after receiving the update request signal from the communication unit 232, it outputs the update permission signal.

[0035] Fig. 3B is a timing chart for explaining the operation of the update permission unit 473. As shown in Fig. 3B, a vertical synchronization signal is input from the drive control unit 43 at a predetermined time interval T1.

[0036] Here, an update request signal is input at time t101, and when a vertical synchronization signal is input at time t102 while the update request signal is input (while the update request signal is HIGH), the update permission unit 473 outputs an update permission signal at time t102. As can be seen from FIG. 3B , the update permission unit 473 does not output an update permission signal simply by inputting a vertical synchronization signal. As such, in the register unit 47, the update permission unit 473 outputs the update permission signal based on the vertical synchronization signal and the update request signal, and when the update permission signal is input, the first register 471 updates the currently held setting value to a new setting value. This allows the setting values ​​of various control parameters to be updated at appropriate times. This point will be described in detail using a comparative example.

[0037] 4A is a circuit diagram showing the configuration of a register unit 47X according to a comparative example. The register unit 47X according to the comparative example includes a first register 471X, a second register 472X, and an update permission unit 473X.

[0038] A new setting value is input to the second register 472X from the communication unit 232 of the body control unit 23. A clock signal is also input to the second register 472X from the outside. The second register 472X temporarily stores the new setting value input from the communication unit 232. The second register 472X outputs the new setting value input from the communication unit 232 to the first register 471X in synchronization with the clock signal.

[0039] The first register 471X receives a new setting value from the second register 472X, an update permission signal from the update permission unit 473X, and an external clock signal. When the update permission signal is received from the update permission unit 473X, the first register 471X synchronizes with the clock signal and updates the currently held setting value to the new setting value received from the second register 472X.

[0040] The update permission unit 473X receives a vertical synchronization signal from the drive control unit 43. When the vertical synchronization signal is received, the update permission unit 473X according to the comparative example outputs an update permission signal.

[0041] Fig. 4B is a timing chart for explaining the operation of the update permission unit 473X. As shown in Fig. 4B, a vertical synchronization signal is input from the drive control unit 43 at a predetermined time interval T1.

[0042] The update permission unit 473X according to the comparative example outputs an update permission signal when a vertical synchronization signal is input, and therefore outputs an update permission signal at each of time t101, time t102, and time t103 when the vertical synchronization signal is input.

[0043] Next, a case where the settings of an image sensor including a register unit 47X according to a comparative example are changed will be described. Fig. 5 is a timing chart for explaining an example where the setting values ​​of setting A, setting B, and setting C are updated in an image sensor including a register unit 47X according to a comparative example. In Fig. 5, it is assumed that all of the setting values ​​of setting A, setting B, and setting C are to be updated within the same frame rate period (at the same timing). Note that the frame rate period refers to the period between two consecutive vertical synchronization signals. In Fig. 5, T11 is the frame rate period.

[0044] 5 , it is assumed that setting values ​​a, b, and c are stored in the first registers 471X for settings A, B, and C, respectively. Here, it is assumed that new setting values ​​a′, b′, and c′ are input from the communication unit 232 of the body control unit 23 to the second registers 472X for settings A, B, and C, respectively, between time t11 and time t12, so as to change the setting value of setting A from a to a′, the setting value of setting B from b to b′, and the setting value of setting C from c to c′. Note that in the example of FIG. 5 , the input of the new setting values ​​a′, b′, and c′ is completed within the same frame rate period.

[0045] The update permission unit 473X in the comparative example outputs an update permission signal when a vertical synchronization signal is input. Therefore, the update permission unit 473X outputs the update permission signal at time t12. As a result, at time t12, the setting values ​​stored in the first register 471X are updated to the new setting values ​​stored in the second register 472X. As a result, the setting values ​​of setting A, setting B, and setting C are simultaneously updated at time t12, and the setting values ​​of setting A, setting B, and setting C after time t12 become setting value a', setting value b', and setting value c', respectively. Therefore, after time t12, an image can be captured with the new setting values ​​set for all of setting A, setting B, and setting C.

[0046] 6 is a timing chart for explaining another example of updating the setting values ​​of setting A, setting B, and setting C in an image sensor including a register unit 47X according to a comparative example. In FIG. 6, it is also assumed that all of the setting values ​​of setting A, setting B, and setting C are to be updated within the same frame rate period (at the same timing).

[0047] In the example of Fig. 6, the interval T12 at which the vertical synchronization signal is output is shorter than the interval T11 at which the vertical synchronization signal is output in Fig. 5. In other words, the example of Fig. 6 shows a case where the frame rate is higher than that of the example of Fig. 5.

[0048] When the frame rate is high, it may not be possible to completely store the new setting values ​​for setting A, setting B, and setting C in the second register 472X within the same frame rate period. In Fig. 6, the new setting values ​​for setting A and setting B can be stored in the second register 472X between time t21 and time t22, i.e., within the same frame rate period, but the new setting value for setting C cannot be stored in the second register 472X, and is instead stored in the second register 472X during the next frame rate period (between time t22 and time t23).

[0049] As a result, when a vertical synchronization signal is input at time t22, the update permission unit 473X outputs an update permission signal, and so at time t22, the setting values ​​stored in the first register 471X for setting A and setting B are updated to the new setting values ​​stored in the second register 472X for setting A and setting B, respectively. However, because the new setting value c' is not stored in the second register 472X for setting C, the setting value for setting C is not updated to the new setting value at time t22.

[0050] When a vertical synchronization signal is input at time t23, the update permission unit 473X outputs an update permission signal, so that the setting value stored in the first register 471X for setting C is updated at time t23 to the new setting value stored in the second register 472X for setting C. That is, in the example of Fig. 6, the setting value for setting C is updated one frame later than the setting values ​​for settings A and B, and is not updated within the same frame rate period (at the same timing).

[0051] As a result, from time t23 onwards, images are captured with the new setting values ​​reflected in Settings A, B, and C, but between times t22 and t23, the setting values ​​for Settings A and B are the new setting values ​​a' and b', but the setting value for Setting C remains the old setting value c, and images are captured. Images captured with only Setting C remaining at the old setting value c may appear distorted. Thus, when updating the settings of the image sensor 21 in synchronization with the vertical synchronization signal, it may not be possible to update the setting values ​​at the appropriate time.

[0052] FIG. 7 is a timing chart for explaining a case where the set values ​​of setting A, setting B, and setting C are updated in the image sensor 21 including the register unit 47 according to the first embodiment.

[0053] 7, the time interval T12 at which the vertical synchronization signal is output is the same as in the example of Fig. 6. In this embodiment, the communication unit 232 of the body control unit 23 transmits to the register unit 47 new setting values ​​for settings that are to be updated within the same frame rate period (that are to be updated at the same timing), and then transmits an update request signal to the register unit 47.

[0054] 7 , for example, suppose that the setting values ​​for setting A, setting B, and setting C are to be updated within the same frame rate period (at the same timing). The communication unit 232 starts transmitting new setting values ​​for setting A, setting B, and setting C to the second register 472 from time t31, and then transmits an update request signal at time t33 when transmission of the new setting value for setting C is completed. This embodiment differs from the comparative example in that no update request signal is input at time t32 when the vertical synchronization signal is input, and therefore no update permission signal is output.

[0055] As a result, at the timing when a vertical synchronization signal is input after the update request signal is input (time t34), the update permission unit 473 outputs an update permission signal. As a result, at time t34, the setting values ​​for setting A, setting B, and setting C stored in the first register 471 are updated to the new setting values ​​stored in the second register 472. As a result, the setting values ​​for setting A, setting B, and setting C can be updated at the same timing (within the same frame period), and from time t34 onwards, an image can be captured with the new setting values ​​set for setting A, setting B, and setting C.

[0056] In this way, in this embodiment, even if a vertical synchronization signal is input, the update permission unit 473 does not output an update permission signal unless an update request signal is input.Therefore, by having the communication unit 232 of the body control unit 23 send an update request signal after sending all new setting values ​​for multiple settings that are to be updated at the same timing, it is possible to update the setting values ​​of multiple settings at the same timing (within the same frame rate period).

[0057] For example, if it is desired to update the setting value of setting D alone, the communication unit 232 of the body control unit 23 transmits an update request signal after transmitting the new setting value of setting D to the register unit 47. In the example of Fig. 7, the communication unit 232 of the body control unit 23 transmits the new setting value of setting D at time t35, and outputs the update request signal at time t36 when transmission of the new setting value of setting D has finished.

[0058] As a result, at time t37 when the vertical synchronization signal is input after the update request signal is input, the update permission unit 473 outputs an update permission signal. As a result, at time t37, the setting value stored in the first register 471 for setting D is updated to the new setting value stored in the second register 472.

[0059] As described above in detail, according to the first embodiment, the image sensor 21 includes pixels 51 that include photoelectric conversion units that convert light into electric charges and that output signals based on the electric charges converted by the photoelectric conversion units, a signal processing unit 45 that processes the signals output from the pixels 51, a first register 471 that holds setting values ​​for controlling at least one of the pixels 51 and the signal processing unit 45 that are input from the body control unit 23, and an update permission unit 473 that outputs an update permission signal that updates the setting values ​​held in the first register 471 when a vertical synchronization signal is input after an update request signal is input from the communication unit 232 of the body control unit 23. This makes it possible to control the timing for updating the setting values ​​for controlling at least one of the pixels 51 and the signal processing unit 45 based on the update request signal, thereby making it possible to update the setting values ​​at appropriate timing.

[0060] Furthermore, in this embodiment, the update permission unit 473 does not output an update permission signal even if a vertical synchronization signal is input if an update request signal has not been input from the communication unit 232 of the body control unit 23. This makes it possible to update the setting value at an appropriate timing.

[0061] Furthermore, according to this embodiment, the camera 1 includes the image sensor 21 and a communication unit 232 that, when updating the setting values ​​of the control parameters held by the image sensor 21 for controlling the operation of the image sensor 21 to new setting values, transmits the new setting values ​​and then transmits an update request signal to the image sensor 21 requesting updating to the new setting values. This makes it possible to control the update timing of the setting values ​​not based on the vertical synchronization signal but based on the vertical synchronization signal and the update request signal, thereby updating the setting values ​​at appropriate timing.

[0062] Furthermore, in this embodiment, when there are multiple control parameters whose setting values ​​are to be updated within a frame rate period, which is the period between two consecutive vertical synchronization signals, the communication unit 232 transmits the update request signal after transmitting new setting values ​​for the multiple control parameters whose setting values ​​are to be updated within the frame rate period, thereby enabling the multiple control parameters to be updated within the same frame rate period.

[0063] In the first embodiment described above, the update permission unit 473 outputs an update permission signal when a vertical synchronization signal is input after an update request signal is input from the communication unit 232 of the body control unit 23, but this is not limited to this. The update permission unit 473 may output the update permission signal at the timing when an update request signal is input from the communication unit 232 of the body control unit 23, for example.

[0064] Second Embodiment Fig. 8 is a diagram showing the configuration of an image sensor 21A according to the second embodiment. The image sensor 21A according to the second embodiment differs from the first embodiment in the configuration of the register unit.

[0065] The image sensor 21A according to the second embodiment includes a first register unit 47A and a second register unit 47B. The first register unit 47A includes a first register 471, a second register 472, and a first update permission unit 473A. The second register unit 47B includes a first register 471, a second register 472, and a second update permission unit 473B. The control parameters for managing the setting values ​​by the first register unit 47A and the control parameters for managing the setting values ​​by the second register unit 47B are determined in advance.

[0066] 9A is a circuit diagram showing the configuration of the first register unit 47A. The configuration of the first register unit 47A is the same as that of the register unit 47 according to the first embodiment. That is, when a vertical synchronization signal is input while an update request signal is being input (HIGH state), the first update permission unit 473A outputs an update permission signal (see FIG. 3B).

[0067] 9B is a circuit diagram showing the configuration of the second register unit 47 B. The second register unit 47 B has a second update permission unit 473 B configured differently from the first update permission unit 473 A of the first register unit 47 A.

[0068] The second update permission unit 473B includes a buffering unit 474 and an AND circuit 475. An update request signal and a vertical synchronization signal are input to the buffering unit 474. When a vertical synchronization signal is input while an update request signal is input, the buffering unit 474 outputs a buffering signal BF to the AND circuit 475 at the timing when the vertical synchronization signal is next input. When an update request signal is not input, the buffering unit 474 may not output the buffering signal BF even when a vertical synchronization signal is input, or may output the buffering signal BF in synchronization with the vertical synchronization signal. The buffering unit 474 can be realized by, for example, a counter circuit.

[0069] When the buffering signal BF is input while the update request signal is being input, the AND circuit 475 outputs an update permission signal.

[0070] 9C is a timing chart for explaining the operation of the second update permission unit 473B. The update request signal output by the communication unit 232 of the body control unit 23 is input to the buffering unit 474 and the AND circuit 475. In FIG. 9C, the update request signal is input from the communication unit 232 at time t71.

[0071] When a vertical synchronization signal is input while an update request signal has been input (time t72), the buffering unit 474 outputs a buffering signal at the timing when the next vertical synchronization signal is input (time t73). When a buffering signal is input while an update request signal has been input at time t73, the AND circuit 475 outputs an update permission signal.

[0072] As a result, for example, when update request signals are input to the first register unit 47A and the second register unit 47B at the same timing, the setting value of the first register 471 of the second register unit 47B is updated at a timing that is delayed by one frame from the update of the setting value of the first register 471 of the first register unit 47A. This makes it possible to update setting values, such as exposure time and gain, whose update timing needs to be different by one frame, at appropriate timing. This point will be described below.

[0073] 10 is a timing chart for explaining a case where the exposure time setting and the gain setting are changed in the image sensor including the register unit 47X according to the comparative example shown in FIG. 10. In FIG. 10, the exposure time is the time between resetting the pixel 51 and reading out the pixel signal from the pixel 51.

[0074] When the exposure time setting value is updated, the output of the image reflecting the updated setting value is delayed by one frame from the timing of the setting update. On the other hand, the gain setting value is reflected from the timing of the setting update. Therefore, the timing of updating the exposure time setting value and the timing of updating the gain setting value must be shifted by one frame.

[0075] In the register unit 47X according to the comparative example shown in Fig. 4A, an update enable signal is output in synchronization with a vertical synchronization signal. Therefore, when an image sensor including the register unit 47X is used, the communication unit 232 of the body control unit 23 transmits a new setting value for the exposure time and a new setting value for the gain, shifted by one frame, as shown in Fig. 10. For example, the communication unit 232 transmits a new setting value for the exposure time at time t41, and transmits a new setting value for the gain at time t42, which is shifted by one frame from time t41.

[0076] As a result, the setting value for the exposure time is updated from setting value t1 to setting value t2 at time t42, and the setting value for the gain is updated from setting value g1 to setting value g2 at time t43, which is one frame later than time t42.

[0077] As a result, before time t43, an image captured with an exposure time setting of t1 and a gain setting of g1 is output, and after time t43, an image captured with an exposure time setting of t2 and a gain setting of g2 is output.

[0078] Here, if the gain setting value cannot be transmitted in the frame following the frame in which the exposure time setting value was transmitted due to reasons such as a high frame rate or a large CPU processing load, a frame will be output in which the exposure time setting and the gain setting do not correspond.

[0079] FIG. 11 is a timing chart for explaining another example of changing the exposure time setting and the gain setting in an image sensor including a register section 47X according to a comparative example.

[0080] 11, the transmission of the gain setting value is not completed within the frame rate period following the frame rate period in which the exposure time setting value was transmitted, but is completed within the frame rate period two frames after the frame rate period in which the exposure time setting value was transmitted, so the timing at which the gain setting value is changed from g1 to g2 is time t44.

[0081] Therefore, between time t43 and time t44, although the exposure time setting value reflected in the output image is t2, the gain setting value is g1, and since the exposure time is not the gain setting value corresponding to t2, it is possible that the image quality, etc. is not as intended.

[0082] 12 is a timing chart for explaining a case where the exposure time setting and the gain setting are changed in the image sensor 21A according to the second embodiment. In this embodiment, the exposure time setting value is managed by the first register unit 47A, and the gain setting value is managed by the second register unit 47B. Note that the setting values ​​of the other settings are managed by the first register unit 47A.

[0083] 12 , the communication unit 232 of the body control unit 23 transmits the new setting value of the exposure time, the new setting value of the gain, and the setting values ​​of other settings to the first register unit 47A and the second register unit 47B, and then transmits an update request signal at time t52. As a result, the update request signal is input to the first update permission unit 473A of the first register unit 47A and the buffering unit 474 and AND circuit 475 of the second register unit 47B.

[0084] After the update request signal is input, the first update permission unit 473A of the first register unit 47A outputs an update permission signal when a vertical synchronization signal is input at time t53. As a result, at time t53, the exposure time setting value is updated from t1 to t2, and the other setting values ​​are updated to new settings.

[0085] On the other hand, after an update request signal is input, when a vertical synchronization signal is input at time t53, the buffering unit 474 of the second register unit 47B outputs a buffering signal at the timing when the next vertical synchronization signal is input (time t54).

[0086] After the update request signal is input, the AND circuit 475 of the second register unit 47B outputs an update permission signal when a buffering signal is input at time t54. As a result, the gain setting value is updated from g1 to g2 at time t54, which is one frame after time t53, when the exposure time setting value was updated.

[0087] As a result, an image in which the gain setting value corresponding to the exposure time setting value is reflected can be output from time t54.

[0088] Furthermore, because the timing for updating the exposure time setting value and the gain setting value can be controlled by the first register unit 47A and the second register unit 47B, there is no need for the body control unit 23 to control the timing for transmitting the exposure time setting value and the gain setting value, thereby simplifying the processing of the body control unit 23.

[0089] As described above in detail, according to the second embodiment, the image sensor 21A includes pixels 51, each including a photoelectric conversion unit that converts light into an electric charge and outputs a signal based on the electric charge converted by the photoelectric conversion unit, a signal processing unit 45 that processes the signal output from the pixel 51, a first register 471 of a first register unit 47A that holds a setting value input from the body control unit 23 to control the pixel 51, and a first register 471 of a second register unit 47B that holds a setting value for controlling the signal processing unit 45 (amplifiers 453(1) to 453(M)). After the setting value held in the first register 471 of the first register unit 47A is updated, the setting value held in the first register 471 of the second register unit 47B is updated. This allows the setting value of the control parameter (exposure time) for controlling the pixel 51 and the setting value of the control parameter (gain) for controlling the signal processing unit 45 to be updated at appropriate timing (shifted by one frame).

[0090] In the second embodiment, the timing of updating the exposure time setting value and the timing of updating the gain setting value are controlled using an update request signal input from the communication unit 232, but this is not limited to this. For example, when the exposure time setting value is changed, the gain setting value is often changed as well. Therefore, when the exposure time setting value is input, the gain setting value is often input as well. Therefore, the input of the gain setting value may be regarded as the input of an update request signal, and the timing of updating the exposure time setting value and the gain setting value may be controlled.

[0091] Furthermore, in the second embodiment, the first register 471 of the second register unit 47B may control the update timing of the first register 471 of the second register unit 47B based on whether the setting value held in the first register 471 of the first register unit 47A has been updated. For example, the first register 471 of the second register unit 47B may update the setting value held in the first register 471 of the second register unit 47B when a vertical synchronization signal is input in a state in which a signal indicating that the setting value held in the first register 471 of the first register unit 47A has been updated has been input.

[0092] In the first and second embodiments, when an update permission signal is input to the first register 471, the first register 471 updates the setting value held in the first register 471 with the setting value input from the second register 472. However, this is not limited to this. For example, an update permission signal may be input to the second register 472, and when the update permission signal is input, the second register 472 may update the setting value held in the first register 471 with the setting value stored in the second register 472.

[0093] The above-described embodiment is not limited to this, and various modifications can be made without departing from the spirit and scope of the invention.

[0094] REFERENCE SIGNS LIST 1 camera 2 camera body 3 interchangeable lens 21, 21A imaging element 23 body control unit 51 pixel 232 communication unit 47 register unit 47A first register unit 47B second register unit 471 first register 472 second register 473 update permission unit 473A first update permission unit 473B second update permission unit

Claims

1. An imaging element comprising: pixels including a photoelectric conversion unit that converts light into electric charges and that output signals based on the electric charges converted by the photoelectric conversion unit; a processing unit that processes the signals output from the pixels; a holding unit that holds setting values ​​for controlling at least one of the pixels and the processing unit; and an update unit that updates the setting values ​​held by the holding unit based on input of an update request signal that requests an update of the setting values.

2. The imaging device according to claim 1, wherein the update section updates the setting value held by the holding section when a vertical synchronization signal is input after the update request signal is input.

3. The imaging device according to claim 2, wherein the update section does not update the setting value held by the holding section when the update request signal is not input, even if a vertical synchronization signal is input.

4. An imaging element as described in any one of claims 1 to 3, wherein the holding unit includes: a first holding unit that holds a first setting value for controlling the pixel; and a second holding unit that holds a second setting value for controlling the processing unit; and the update unit updates the first setting value held by the first holding unit when a vertical synchronization signal is input after the update request signal is input, and updates the second setting value held by the second holding unit when a vertical synchronization signal is input after the first setting value held by the first holding unit has been updated.

5. The image sensor described in any one of claims 1 to 3, wherein the holding unit includes: a first holding unit that holds a first setting value for controlling the pixel; and a second holding unit that holds a second setting value for controlling the processing unit; and wherein the updating unit includes: a first updating unit that, when a vertical synchronization signal is input after the update request signal is input, updates the first setting value held by the first holding unit to a third setting value, and, if the update request signal is not input, does not update the first setting value held by the first holding unit to the third setting value even if a vertical synchronization signal is input; and a second updating unit that, when the update request signal is input, updates the second setting value held by the second holding unit to a fourth setting value in accordance with the vertical synchronization signal that is input next to the first vertical synchronization signal that is input after the update request signal is input, and, if the update request signal is not input, does not update the second setting value to the fourth setting value even if the vertical synchronization signal is input.

6. The imaging device according to claim 4 or 5, wherein the first setting value is a setting value for an exposure time, and the second setting value is a setting value for a gain.

7. An imaging element comprising: pixels including a photoelectric conversion unit that converts light into electric charges and that output signals based on the electric charges converted by the photoelectric conversion unit; a processing unit that processes the signals output from the pixels; a holding unit that holds a first setting value for controlling at least one of the pixels and the processing unit; an update enabling unit that outputs an update enabling signal when a vertical synchronization signal and a predetermined signal are input; and an update unit that holds a second setting value and, when the update enabling signal is input, updates the first setting value held by the holding unit with the second setting value.

8. The imaging element according to claim 7, wherein the holding unit includes a first register, the update unit includes a second register, and when the update permission signal is input, the second register updates the first setting value held in the first register with the second setting value held in the second register.

9. The imaging device according to claim 7 or 8, wherein the predetermined signal is an update request signal that requests updating of the first setting value held by the holding unit.

10. An imaging device according to claim 7 or 8, wherein the predetermined signal is a signal indicating that a setting value for a predetermined control parameter has been input.

11. An imaging element comprising: pixels including a photoelectric conversion unit that converts light into electric charges and that output signals based on the electric charges converted by the photoelectric conversion unit; a processing unit that processes the signals output from the pixels; a holding unit that holds a first setting value for controlling the pixels and a second setting value for controlling the processing unit; and an update unit that updates the first setting value held in the holding unit when the second setting value is input after the first setting value is input.

12. The image sensor according to claim 11, wherein the processing unit is an amplifier, and the holding unit holds a setting value for an exposure time as the first setting value, and holds a setting value for a gain of the amplifier as the second setting value.

13. The imaging element of claim 12, wherein the update unit updates the first setting value held by the hold unit when the second setting value is input after the first setting value is input and a vertical synchronization signal is input, and updates the second setting value when a vertical synchronization signal is input after the first setting value is updated.

14. An imaging device comprising: an imaging element; and a transmitting unit that, when updating a setting value of a control parameter held by the imaging element for controlling the operation of the imaging element to a new setting value, transmits the new setting value and then transmits an update request signal to the imaging element requesting updating to the new setting value.

15. The imaging device according to claim 14, wherein, when there are multiple control parameters whose setting values ​​are to be updated within a frame rate period, which is the period between two consecutive vertical synchronization signals, the transmission unit transmits the update request signal after transmitting new setting values ​​for the multiple control parameters whose setting values ​​are to be updated within the frame rate period.

16. An imaging device comprising: an imaging element according to any one of claims 1 to 13; and a transmitting unit that, when updating a setting value held by said imaging element for controlling the operation of said imaging element to a new setting value, transmits said new setting value and then transmits an update request signal to said imaging element requesting updating to said new setting value.

Images