JP2019080268A - Power supply device and control method thereof - Google Patents

Abstract

To solve a problem in which horizontal stripe noise is generated in an image due to the influence of power supply noise superimposed at the time of reading-out of a noise signal and a light signal component of an imaging element.SOLUTION: A power supply device includes a plurality of imaging elements each of which converts an optical image into an electrical signal, a switching power supply that turns on/off a switching element to generate output voltages of different values from an input voltages, a timing signal generation unit that controls a readout timing of the image element, a phase detection unit that detects switching pulses of the switching power supply and readout timings of the plurality of imaging elements, and a phase correction unit that corrects the switching timing of the switching power supply, and the phase correction unit corrects the switching timing of the switching power supply on the basis of information detected by the phase detection unit.SELECTED DRAWING: Figure 6A

Description

  The present invention relates to a power supply of an imaging apparatus and a control method thereof, and more particularly to a technology for reducing deterioration in image quality.

  Generally, in an imaging device such as a digital camera or digital video camera, a CCD or CMOS image sensor (hereinafter referred to as a "CMOS sensor") is used as an imaging element, and a still image or a moving image imaged by the imaging element is stored. doing.

  Further, imaging apparatuses are becoming multifunctional, and apparatuses having two imaging elements are known. This image pickup apparatus includes a half mirror which splits a light flux reaching from an interchangeable lens into two on an optical path, and has a feature of receiving two divided light fluxes by different image pickup elements. High-speed continuous shooting can be performed by alternately shooting using two imaging elements. Furthermore, by capturing a moving image with the first imaging element and capturing a still image with the second imaging element, it becomes possible to capture a still image without stopping the moving image capturing during the capturing of the moving image.

  FIG. 2 shows a part of the configuration of an imaging apparatus having two imaging elements, and a photographing operation of a general imaging apparatus will be described. In FIG. 2, when the power switch (not shown) is turned on in the imaging apparatus, the switching power supply (501) of the power supply unit is activated to supply power to each block. When the user depresses the release button, which is one of the operation units (109), to a predetermined position (half-pressed state), a preparation operation for photographing such as auto focus and exposure setting is started. Further, when the release button is pushed in and fully pressed, the system control unit (106) controls the imaging system such as the timing signal generation circuit (104), the first imaging device (101) and the second imaging device (102). The photographing operation is started.

  FIG. 3 shows a pixel unit equivalent circuit of the CMOS sensor. As shown in FIG. 3, in the pixel, a photodiode (PD) (401) as a photoelectric conversion means, a transfer switch (TX) (402), a reset switch (TRES) (403), and a source constituting a pixel amplifier An amplification transistor (410) of the follower (SF) is disposed. Furthermore, a load current source (407) and a first switch (408) are arranged.

  In addition, a row selection switch (TSEL) (406) is provided in the pixel. The gate of the transfer switch (402) is connected to TXTX. The gate of the reset switch (403) is connected to RESRES. The gate of the row select switch (406) is connected to SEL SEL. In addition, a second switch (409) for limiting the potential of the vertical output line (412) is provided, and a voltage Vclip corresponding to the limit potential of the vertical output line is connected to the gate of the second switch (409) It is done.

  When the row selection switch (406) is on (Φ SEL = low level) and the first switch (408) is on (Φ I off = high level), the load current source (407), the first switch (408) and the source current The follower (410) is activated. Here, the charge stored in the photodiode (401) is transferred to the floating diffusion region (411) which is the gate of the source follower (410) by turning on the transfer switch (402) (Φ TX = low level) .

  (404) is a reset power supply, and (405) is a power supply for driving the source follower (410). The output of the selected row is generated on the vertical output line (412) and is stored in the signal storage unit (414) via the transfer gates (413a) and (413b). The outputs temporarily stored in the signal storage unit (414) are sequentially read out to an output amplifier unit (not shown) by a horizontal scanning circuit (not shown).

  FIG. 4 is a timing chart when the CMOS sensor having the pixel portion equivalent circuit as shown in FIG. 3 is driven.

  In FIG. 3, when TXTX becomes active at the timing of the all-pixel reset period T1, charges of the photodiodes (401) of all the pixels are transferred to the gate of the source follower (410) via the transfer switch (402). Then, the photodiode (401) is reset. Activate ΦRES at the same timing. As a result, the potential of the FD (411) which is the gate of the source follower (410) = the potential of the transfer gate becomes the same level as that of the reset power supply (404), and is in a reset state.

  In this state, the cathode charge of the photodiode (401) is averaged and transferred to the FD (411) which is the gate of the source follower (410). However, by increasing the capacitance component (415) of the capacitor of the gate of the source follower (410), the cathode of the photodiode (401) becomes similar to the reset level.

  Then, after the time T2 has elapsed, the accumulation of the photocharge of the photodiode (401) is completed. In this state, photo charge is accumulated in the photodiode (401).

  Next, the read operation for each row is started. When Φ SEL becomes active and the row selection switch (TSEL) (406) is turned on, the source followers (SF) (410) of all the pixels connected to the n-th row are activated. Then, in the FD (411) which is the gate of the SF (410) composed of the pixel amplifier, RESRES becomes active in the T3 period, the TRES (403) is turned on, and the FD (411) which is the gate of the SF (410). Is reset.

  At this time, a dark level signal is output to the vertical output line (412), ΦTN becomes active, the transfer gate (413b) is turned on, and the dark level signal output is held in the signal storage unit (414). The period from T3 to T4 is called an "N reading" (noise component readout) period.

  Next, after the transfer (N reading) of the signal at the dark level to the signal storage unit (414) is completed, the signal is stored in PD (401) by activating the transfer switch (402) by making 期間 TX active for T 5 period. Transfer the charge to the FD (411) which is the gate of the SF (410). Here, ΦTS is active for a period of T6, and the transfer gate (413a) is turned on, whereby the signal stored in the photodiode is held in the signal storage portion (414). A period in which the signal output of the pixel signal level is held is referred to as an "S reading" period.

  Then, by performing the difference calculation operation of the signal level and the dark level (hereinafter referred to as "S-N operation"), it becomes possible to avoid the influence of fixed pattern noise and the like caused by manufacturing variations and so on. It is possible to acquire an image with reduced horizontal stripe noise in shooting.

  However, as shown in the timing chart of the imaging device in FIG. 4, since the “N reading” and “S reading” operations are not performed at the same time, noise generated when the switching power supply (501) operates is “ It will be superimposed at the time of "N reading" and "S reading". A state in which the timing of the switching pulse of the switching power supply is different at the “N reading” and the “S reading” is shown in FIG. In FIG. 5, when the timing of the switching pulse of the switching power supply is different, the amount of difference between the potential levels at the “N reading” and the “S reading” becomes large, so horizontal stripe noise occurs.

  To solve the above problem, there is a technique in which horizontal stripe noise is reduced by the difference calculation unit by reducing the amount of difference in potential level at the time of “N reading” and “S reading” for each row. For example, as proposed by patent document 1, the method of selecting an appropriate thing from the drive frequency of the switching power supply prepared according to the operation mode and changing it can be considered.

  Moreover, as proposed by patent document 2, the means which detects the noise period which generate | occur | produces from a power supply, and changes the read-out period of an image pick-up element according to the period of power supply noise is also considered.

Unexamined-Japanese-Patent No. 2008-219292 Unexamined-Japanese-Patent No. 2010-056795

  However, if the frequency is selective as in Patent Document 1, it is not possible to cope with the frequency that is deviated from the frequency to be matched due to the surrounding environment or component variation, so even if the frequency is changed May not.

  In addition, in the switching power supply, sharp power supply voltage fluctuation occurs at the switching timing. When the image pickup element performs a reading operation such as "N reading" or "S reading" at this switching timing, the difference amount can not be made constant due to the influence of the steep power supply voltage fluctuation, so horizontal stripe noise It may occur.

  Further, Patent Document 2 does not consider even the case of an imaging apparatus having a plurality of imaging elements. For example, in the case of an imaging apparatus having two imaging elements, the first imaging element can obtain an image with reduced horizontal stripe noise by matching the readout cycle of the first imaging element with the drive frequency of the switching power supply. However, when the imaging operation is performed by changing the readout cycle of the first imaging element and the second imaging element, the readout timing of the second imaging element and the switching timing of the switching power supply may overlap. Therefore, horizontal stripe noise may occur in one imaging element.

  The present invention has been made in view of the above problems, and detects the timing of each "N reading" and "S reading" of a plurality of imaging devices and the switching timing of the switching power supply, and corrects the switching pulse so that both do not overlap. The purpose is to reduce the horizontal stripe noise of the image by doing.

  In order to solve the above problems, an imaging device according to the present invention includes a plurality of imaging elements for converting an optical image into an electrical signal, and a switching power supply for turning on / off switching elements to generate output voltages of different values from input voltages. A timing signal generation unit that controls readout timing of an imaging element; a phase detection unit that detects switching timings of the switching power supply and each readout timing of the plurality of imaging elements; and a phase correction unit that corrects switching timing of the switching power supply The phase correction unit may correct the switching timing of the switching power supply based on the information detected by the phase detection unit.

  According to the present invention, for an imaging device having a plurality of imaging elements, the readout operation of each imaging element is not performed at the switching timing of the switching power supply at the time of "N reading" and "S reading" of each imaging element. Can be controlled. Therefore, the amount of difference between the potential levels at the “N reading” and “S reading” of each imaging device can be reduced, so that the generation of horizontal stripe noise can be reduced.

It is a block diagram of an imaging device. It is the figure which represented the structure of the conventional imaging device typically. It is an equivalent circuit schematic example of an image sensor. It is a timing chart which shows the operation timing of an image sensor. It is the figure which showed a mode that the timing of the switching pulse of the switching power supply at the time of "N reading" and "S reading" differs. It is a figure showing composition of an imaging device concerning a 1st embodiment of the present invention. It is a figure showing the composition of the frequency control part concerning the 1st and 2nd embodiment of the present invention. It is a figure showing composition of a phase amendment part concerning a 1st embodiment of the present invention. It is a figure showing the composition of the imaging device concerning a 2nd embodiment of the present invention. It is the figure which showed the relationship of the switching pulse of switching power supply, and the phase difference of the imaging read-out pulse of each image pick-up element. It is a flow chart concerning a 1st embodiment of the present invention. It is a flowchart concerning the 2nd Embodiment of this invention. It is a figure showing the relationship between the read-out timing of a several image pick-up element at the time of using the means of the 1st Embodiment of this invention, and the switching pulse of switching power supply. It is a figure showing the relation of the reading pulse of a plurality of image sensors at the time of using the means of a 2nd embodiment of the present invention, and the switching pulse of switching power supply. FIG. 7 is a diagram showing how noise difference amounts at “N reading” and “S reading” are constant for each row by performing frequency synchronization control and phase correction control.

Embodiment 1
FIG. 1 is a block diagram showing the main part of a system of an imaging device. FIG. 6A is a schematic view showing a part of the configuration of a power supply unit and an imaging apparatus according to an embodiment of the present invention. The configuration of an imaging apparatus according to a first embodiment of the present invention will be described using FIGS. 1 and 6A.

In FIG. 1, the imaging device is, for example, a lens-interchangeable digital single-lens reflex camera, and includes a camera body (100) and an imaging lens (200) for guiding incident light to an imaging element.
First, the configuration of the camera body (100) will be described.

  The first imaging element (101) and the second imaging element (102) are constituted by a CMOS type imaging sensor, and convert an optical signal which is an optical image into an electric signal. A light beam incident on the imaging lens (201) in the lens unit (200) is divided into light beams in mutually different first and second directions by the half mirror (103) in the imaging device (100), and the first An image is formed as an optical image on the imaging element (101) and the second imaging element (102). Then, the image of the formed subject is converted into an electrical image signal and output from the first imaging device (101) and the second imaging device (102).

  The timing signal generation circuit (104) receives a reference clock signal or control signal for driving the imaging system from the image processing unit (105), and transmits the first imaging element (101) and the second imaging element (102). And supply timing signals such as control signals which define the operation timings.

  The image processing unit (105) performs predetermined arithmetic processing on the video signals input from the first imaging device (101) and the second imaging device (102), and based on the calculation result obtained. Pixel processing such as pixel interpolation processing, color conversion processing, white balance processing, etc., and output to various display units (110) through a system control unit (106). The image processing unit (105) has an image compression function such as JPEG.

  The system control unit (106) performs various calculations and controls the overall operation of the imaging apparatus including the operations of the first imaging element (101) and the second imaging element (102).

  The memory circuit (107) also includes an electrically erasable and storable nonvolatile memory, and stores various parameters, set values such as ISO sensitivity, photographing modes, various correction data, and the like.

  The various display unit (110) has a liquid crystal device, a speaker, etc. for displaying the operation status and messages of characters, images, sounds etc. according to the execution of the program in the system control unit (106). , An LED, and a combination of a sound emitting element and the like. In addition, some of the various display units (110) are provided in the optical finder and the like.

  The recording circuit (111) is a circuit that reads and writes to a removable recording medium such as a semiconductor memory for recording or reading image data.

  The operation unit (109) is operation means for inputting various predetermined operation instructions to the system control unit (106). These operation means are configured by any one or a combination of a switch, a dial, a touch panel, pointing by sight line detection, a voice recognition device, and the like.

  A mode switching unit (108) is a switch for switching and setting various shooting modes such as still image shooting, live view shooting, and moving image shooting.

  The power supply circuit (112) is composed of a battery detection unit, a current detection unit, a protection circuit, a DCDC converter, an LDO regulator, etc., and when battery attachment / detachment, battery type, remaining amount detection or overcurrent is detected. It has the function of protecting the load circuit connected to the power supply circuit by shutting off the power supply. Based on an instruction from the system control unit (106), the DCDC converter is controlled to supply a desired power supply voltage to each unit of the camera body (100) for a desired period. The power supply units (114) and (301) are connectors for connecting the battery (302) and the camera body (100). The power source (302) comprises a primary battery such as an alkaline battery or lithium battery, a secondary battery such as a Nicd battery, a NiMH battery, a Li battery or the like, an AC adapter or the like.

  Next, the configuration of the lens unit (200) will be described. The lens unit (200) and the imaging device (100) are mechanically joined via lens mount mechanisms (204) and (113) and are detachable. The lens unit (200) includes a photographing lens (201), a lens drive circuit (202), and a lens control unit (203). The lens mount (204) also includes a connector for electrically connecting the lens unit (200) to the camera body (100), and control signals and states between the camera body (100) and the lens unit (200). Transmit signals, data signals, etc.

  Furthermore, it has a function to supply the power of the lens unit (200) from the camera body side (100). Further, the connector may be configured to transmit not only an electrical signal but also a medium such as an optical signal or an audio signal. Further, although only one taking lens (201) is shown in FIG. 1 for the sake of simplification, it is actually composed of a large number of taking lens groups.

  A lens control unit (203) controls the entire lens unit (200). The lens control unit (203) is provided with a memory (not shown) for storing various constants for lens operation, variables, programs and the like.

  The system control unit (106) of the camera body (100) calculates the defocus amount using the output information of the imaging device, and the system control unit (106) calculates the defocus amount of the lens unit (200) based on the calculated defocus amount. Communication is performed via the lens control unit (203), and focusing is performed by controlling the lens drive circuit (202). The lens drive circuit (202) also includes vibration detection means for camera shake mitigation at the time of shooting and a control circuit for driving a movable shift lens for camera shake mitigation. The camera shake is output as an electric signal by the vibration detection means, and the movable shift lens is moved based on the calculation result of the camera shake amount to reduce the camera shake.

  FIG. 8A is a flowchart showing an imaging operation according to an embodiment of the present invention. FIG. 9A is a diagram showing the relationship between the read timings of a plurality of imaging devices and the switching pulse of the switching power supply when the means of the embodiment of the present invention is used. A series of flow of the imaging operation of the present embodiment will be described using FIGS. 6A, 8A, and 9A.

  After the imaging device is activated by the power switch in (S901), the imaging system such as the first imaging element (101) and the second imaging element (102) is not supplied with power until transition to the main imaging operation. It becomes.

  In (S902), the imaging apparatus selects a shooting mode such as still image shooting, moving image shooting, live view shooting, etc. by the operation of the mode switching unit (108) by the user. The system control unit (106) determines whether to use two imaging elements according to the selected mode.

  On the other hand, if it is determined in (S902) that the system control unit (106) performs an imaging operation with the two imaging elements (101) and (102), the process proceeds to (S903). In (S903), the system control unit (106) controls the frequency control unit (601) so that the frequency of the switching pulse (603) output from the frequency control unit (601) becomes the drive frequency (fsw1). The signal (602) is sent to the frequency control unit (601).

  The drive frequency (fsw1) is expressed by the following equation (1).

fsw1 = K1 Δ Δsn3 equation (1)
Δsn3: common multiple of Δsn1 and Δsn2

  Here, K1 is an integer multiplied by the switching frequency that can be driven by the switching power supply. Δsn1 is a period from the “N1 reading” timing which is the noise signal reading of the first imaging element (101) to the “S1 reading” timing which is the light signal reading. Further, Δsn2 is a period from the “N2 reading” timing which is the noise signal reading of the second imaging element (102) to the “S2 reading” timing which is the light signal reading. Therefore, the drive frequency (fsw1) of the two imaging elements is calculated as Δsn3 from the common multiple of Δsn1 and Δsn2, and is calculated by dividing K1 which is an integer by which the switching power supply can drive to the switching frequency that can be driven.

  The switching pulse (603) generation means of the switching power supply (501) in the frequency control unit (601) is, for example, a phase locked loop (PLL) (701) and a frequency divider (702) (703) shown in FIG. It shall be carried out using.

  On the other hand, when the system control unit (106) determines in (S902) that the first imaging element (101) performs the photographing operation, the process proceeds to (S904). In (S904), the system control unit (106) controls the frequency control unit (601) so that the frequency of the switching pulse (603) output from the frequency control unit (601) becomes the drive frequency (fsw2). The signal (602) is sent to the frequency control unit (601).

The driving frequency (fsw2) is expressed by the following equation (2).
fsw2 = K2 Δ Δsn1 equation (2)

Here, K2 is an integer multiplied by the switching frequency that can be driven by the switching power supply. In the present embodiment, the drive frequency (fsw2) shows the case where the first imaging element (101) is selected as one imaging element, but the second imaging element (102) is selected as one imaging element. You may When it is selected to shoot with the second imaging element (102), the driving frequency (fsw2) is expressed by the following formula (3).
fsw2 = K3 Δ Δsn2 equation (3)

  Here, K3 is an integer multiplied by the switching frequency that can be driven by the switching power supply.

  By turning on the photographing start switch in (S905), the photographing operation by the imaging device is started. In (S906), the system control unit (106) sends an imaging system reference clock (503) to the frequency control unit (601). The frequency control unit (601) converts the imaging system reference clock (503) into a switching pulse (603) of the drive frequency (fsw1) or (fsw2) set in (S903) or (S904). Then, a power control signal (502) instructing power supply of the imaging system is sent to the switching power supply (501), and the switching power supply (501) performs power output (607) to the imaging system.

  In (S907), the system control unit (106) sends an imaging system control signal such as an imaging system reference clock, horizontal scanning signal, vertical scanning signal, etc. to the timing signal generation circuit (104), Start the read operation.

  In (S908), the phase detection unit (606) reads the switching pulse (605) input to the switching power supply (501), and the readout pulse (608) of the optical signal or noise signal of the first imaging device and the second imaging device. Detect (609).

  In (S909), the phase difference between the switching pulse (605) of the switching power supply (501) and the imaging readout pulse (608) (609) of each imaging device is calculated from the detected phase.

  FIG. 7 is a view showing the relationship between the phase difference between the switching pulse (605) of the switching power supply (501) and the imaging readout pulse (608) (609) of each imaging device. As shown in FIG. 7, the phase difference between the switching pulse (605) at the time of readout operation on the nth row and the readout pulse (608) of the first imaging device is taken as the first phase difference ΔRn_1, and the switching pulse (605) And the read pulse (609) of the second imaging element as a second phase difference ΔRn_2.

  In (S910), the phase detection unit (606) calculates the first phase difference ΔRn + 1_1 and the second phase difference ΔRn + 1_2 at the readout timing of the next row n + 1. The first phase difference ΔRn + 1_1 is a parameter represented by ΔRn + 1_1 = ΔRn_1−β1. Here, β1 is the shorter one from the rising or falling edge of the switching pulse (605) immediately before the rising edge of the horizontal scanning signal in the n + 1th row to the rising edge of the horizontal scanning signal in the n + 1th row. It is a parameter representing time difference. β1 is represented by the following formula (4).

Thd ÷ Tfsw1 = Q remainder α1
α1 = Thd-Tfsw1 × Q
Tfsw1 = 1 ÷ fsw1
If α1 T Tfsw1 / 2, then β1 = α1-Tfsw1 / 2
If α1 <Tfsw1 / 2, then β1 = α1 equation (4)

  Here, Thd is the period of the horizontal scanning signal, and Tfsw1 is the period of the switching pulse (605) determined by the reciprocal of fsw1. The quotient obtained by dividing Thd by Tfsw1 is Q, and the remainder is α1. This is because the period of the switching pulse (605) is not an integral multiple of the period of the horizontal scanning signal, so that a phase shift of α1 occurs in the phase relationship between the two in every row reading. Since β1 represents the shorter time difference from the rising or falling edge of the switching pulse (605) to the rising edge of the horizontal scanning signal in the n + 1th row, α1 is larger than the half cycle of the switching pulse (605) And the half cycle of the switching pulse (605).

  On the other hand, when α1 is smaller than the half cycle of the switching pulse (605), β1 = α1. In the present embodiment (S902), although the relational expression is shown using fsw1 because it is selected to drive with two image sensors, one image sensor may be selected. When it is selected in (S902) that imaging is performed by one imaging device, β2 is expressed by the following equation (5).

Thd ÷ Tfsw2 = Q remainder α 2
α 2 = Thd − Tfsw 2 × Q
Tfsw2 = 1 ÷ fsw2
If α2 T Tfsw2 / 2, β2 = α2-Tfsw2 / 2
If α2 <Tfsw2 / 2 β2 = α2 Equation (5)

Similarly, the phase difference ΔRn + 1_2 is represented by ΔRn + 1_2 = ΔRn_2-β1.
In (S911), it is determined whether or not the relationship | ΔRn + 1_1 | ≦ X holds. X is a value that takes into consideration the influence of frequency accuracy variations due to the peripheral environment of the spike width of the switching power supply (501) and manufacturing variations of the components that make up the hardware.

  Here, ΔRn + 1_1 is compared with X in order to determine whether or not the readout timing of the imaging element in the next row n + 1 is overlapped with the spike region because a sharp power supply voltage fluctuation occurs in the spike region. . If the relational expression holds, there is a possibility that the switching timing of the switching power supply (501) and the reading timing of the first imaging device (101) may overlap in the reading of the next row n + 1, so (S912) Transition. In (S911), when the relational expression does not hold, it is not necessary to perform the phase correction for the first imaging element (101), and the process proceeds to (S915).

  In (S912), it is determined whether or not the relationship | ΔRn + 1_2−Δt | ≦ X holds. Here, Δt is a parameter representing a predetermined phase correction amount of the switching pulse (605). For example, Δt is a correction amount that can be shifted by the spike width of the switching power supply (501) or more.

  This is because the switching power supply (501) generates steep power supply voltage fluctuation corresponding to the spike width at the switching timing, and when the read operation is performed in this region, horizontal stripe noise is generated. Therefore, in order to control so as not to perform the read operation in the region where the sharp power supply voltage fluctuation occurs, the phase correction for the spike width or more is performed. In the relational expression (S912), in order to avoid superimposition of the readout timing of the first imaging element (101) and the switching pulse of the next row n + 1, the correction for Δt results in the switching timing and the second It is determined whether the readout timing of the imaging element (102) does not overlap. When the relational expression holds, since the timings of the two overlap, the process proceeds to (S913).

  The phase correction unit (604) sets the phase of the switching pulse (605) to be a multiple of Δt so that the switching timing and the readout timing of the first and second imaging elements (101) and (102) do not overlap in (S913). By shifting by 2Δt, overlapping of both is avoided.

  On the other hand, when the relational expression does not hold in (S912), the process proceeds to (S914), and the phase correction unit (604) shifts the phase of the switching pulse (605) by Δt. After the phase shift is completed, the process proceeds to (S919).

  Here, it is assumed that the phase correction means in the phase correction unit (604) is performed using, for example, a plurality of delay circuits (801) and a selector (802) as shown in FIG. 6C. The phase correction unit (604) determines the signal of which delay circuit (801) to be output by the selector (802) based on the phase correction information (610) received from the phase detection unit (606). The phase correction of the input pulse (603) of the phase correction unit (604) is performed. Here, the input pulse is an output pulse of the frequency control unit (601).

  On the other hand, if the relational expression does not hold in (S911), the process shifts to (S915), and it is determined whether the relation | ΔR n + 1 — 2 ≦ X holds. When the relational expression is satisfied, there is a possibility that the switching timing of the switching power supply (501) and the reading timing of the second imaging element (102) may overlap in the reading of the next row n + 1 row (S916) . In (S915), when the relational expression does not hold, the process proceeds to (S919) because it is not necessary to perform phase correction.

  Next (S916), it is determined whether the relational expression holds. As a result of performing Δt phase correction to avoid superposition of the switching timing of the switching power supply (501) and the readout timing of the second imaging element (102) in the next row n + 1, the switching timing and the first It is determined whether the readout timing of the image pickup element (101) is not superimposed. When the relational expression holds, since the timings of the two are superimposed, the process proceeds to (S917), and the phase correction unit (604) shifts the phase of the switching pulse (605) by 2Δt.

  On the other hand, when the relational expression does not hold in (S916), the process proceeds to (S918), and the phase correction unit (604) shifts the phase of the switching pulse (605) by Δt. After the phase shift is completed, the process proceeds to (S919).

  (S919) The subsequent flowcharts describe processing in the case where imaging of the first imaging device (101) and the second imaging device (102) is completed, or reimaging of one of the imaging devices is performed.

  In (S919), it is determined whether the imaging of the first imaging element (101) is completed. If the imaging has been completed, the process proceeds to (S920).

  On the other hand, when the photographing is not completed in (S919), the process proceeds to (S921). In (S920), it is determined whether the imaging of the second imaging element (102) is completed. If the imaging has been completed, the process proceeds to (S930).

  On the other hand, if the photographing is not completed in (S920), the process proceeds to (S922). In (S922), it is determined whether the photographing operation is to be performed again by the first imaging element (101). When the photographing operation is not performed again by the first imaging element (101), the process returns to (S908), and the same processing is performed.

  On the other hand, in (S922), when photographing with the first imaging element (101) again, the process proceeds to (S923). (S923) Whether the change in the period Δsn1 from the “N1” reading timing of the first imaging element (101) to the “S1 reading” timing is necessary in accordance with the photographing mode change of the first imaging element (101) Make a decision on If the change is not necessary, the drive frequency of the switching power supply (501) is not changed, and the process proceeds to (S925), and the read operation of the first imaging element (101) is started.

  On the other hand, in (S923), when changing the readout period of the first imaging element (101), the process proceeds to (S924).

  In (S924), the frequency control unit (601) is set by the system control unit (106) so that the frequency of the switching pulse (603) becomes the drive frequency (fsw1) based on the read timing of the two imaging elements. In (S925), the readout operation of the first imaging element (101) is started, and the process returns to (S908), and the same processing is performed.

  On the other hand, in (S919), when the imaging of the first imaging device (101) is not completed, the process proceeds to (S921), and it is determined whether the imaging of the second imaging device (102) is completed. Do. If the photographing has been completed, the process proceeds to (S926). On the other hand, if the photographing is not completed in (S921), the process returns to (S908), and the same processing is performed.

  In (S926), it is determined whether the second imaging element (102) performs the photographing operation again. When the photographing operation is not performed by the second imaging element (102) again, the process returns to (S908), and the same processing is performed.

  On the other hand, in (S926), when imaging with the second imaging element (102) again, the process proceeds to (S927). In (S927), whether it is necessary to change the period Δsn2 from the “N2” reading timing of the second imaging element (102) to the “S2 reading” timing accompanying the imaging mode change of the second imaging element (102) Make a decision. If it is not necessary to change, the drive frequency of the switching power supply (501) is not changed, and the process proceeds to (S929), and the read operation of the second imaging element (102) is started.

  On the other hand, in (S927), when changing the readout cycle of the second imaging element (102), the process proceeds to (S928). In (S928), the frequency control unit (601) is set by the system control unit (106) such that the frequency of the switching pulse (603) becomes the drive frequency (fsw1) based on the read timing of the two imaging elements.

  In (S929), the readout operation of the second imaging element (102) is started, and the process returns to (S908), and the same processing is performed. In (S930), it is determined whether the power switch is off. If the power switch is not off, the process proceeds to (S931), and it is determined whether or not the imaging mode has been changed. When the photographing mode is not changed in (S931), it is detected that the photographing start switch in (S905) is ON.

  On the other hand, when the photographing mode is changed in (S931), the photographing mode in (S902) is selected. On the other hand, when the power switch is turned off in (S931), the process proceeds to (S932), and the power of the imaging apparatus is turned off.

  In FIG. 9A, as an example, the switching timing and the readout timing of the second imaging element (102) are superimposed on the n + 1th line of the next line, and ΔRn + 1_2 = ΔRn_2−β1 ≒ 0 is shown. Therefore, by performing phase correction control of the switching pulse (605) by Δt, superposition of the switching timing and the readout timing of the second imaging element (102) is avoided in the n + 1th row. By performing phase control of the switching pulse using the means of the embodiment of the present invention, the switching timing of the switching power supply can be avoided without overlapping at the “N reading” and “S reading” timings of the two imaging devices. I understand that it is.

  In the first embodiment, the frequency control unit (601) controls the drive frequency of the switching power supply (501). However, the frequency control unit may not be provided. Since the switching timing of the switching power supply becomes the same as the “N reading” and the “S reading” timing by frequency control as in this embodiment, the phase difference between each reading timing and the switching timing is made the same. I can do things. Therefore, if either one of "N reading" or "S reading" timing is detected, the other becomes the same phase difference relation, so in the first embodiment, "N reading" or "S reading" in (S907) The system is configured to detect either one of the timings.

  However, the present invention is not limited to the configuration having the frequency control unit (601). In the case of the configuration without the frequency control unit (S907), the phase detection unit (606) receives the switching pulse (605) input to the switching power supply (501) and the two imaging devices (101) and (102). By detecting the timings of both “N reading” and “S reading” and calculating respective phase differences, control may be performed so that switching timings do not overlap.

Second Embodiment
The description of FIG. FIG. 6D is a schematic view showing a part of the configuration of a power supply unit and an imaging apparatus according to an embodiment of the present invention. Also, FIG. 8B is a flowchart showing an imaging operation in the embodiment of the present invention. FIG. 9B is a diagram showing the relationship between the readout timing of a plurality of imaging devices and the switching pulse of the switching power supply and the timing of changing the frequency of the switching pulse of the switching power supply. A series of flow of the imaging operation of the present embodiment will be described using FIGS. 6D, 8B, and 9B.

  In (S1101), after the imaging device is activated by the power switch, power is not supplied to the imaging system such as the first imaging element (101) and the second imaging element (102) until transition to the main imaging operation It becomes a state.

  In (S1102), the imaging apparatus selects a shooting mode such as still image shooting, moving image shooting, live view shooting, etc. by the operation of the mode switching unit (108) by the user. The system control unit (106) determines whether to use two imaging elements according to the selected mode. If it is determined in (S1102) that the system control unit (106) performs an imaging operation with the two imaging elements (101) and (102), the process proceeds to (S1103). In (S1103), the system control unit (106) sends a frequency control signal (Fab) to the frequency control unit (601) so that the frequency of the switching pulse (605) output from the frequency control unit (601) becomes the driving frequency (fsw1). 602).

  On the other hand, if it is determined in (S1102) that the system control unit (106) performs the photographing operation with one imaging device, the process proceeds to (S1104). In (S1104), the system control unit (106) controls the frequency control unit (601) so that the frequency of the switching pulse (605) output from the frequency control unit (601) becomes the driving frequency (fsw2). The signal (602) is sent to the frequency control unit (601). The drive frequency (fsw1) is used as the frequency, and the drive frequency (fsw2) is used as the first embodiment (1), (2) and (3).

  In (S1105), when the photographing start switch is turned on, the photographing operation by the imaging element is started. In (S1106), the system control unit (106) sends an imaging system reference clock (503) to the frequency control unit (601). Then, the frequency control unit (601) outputs a switching pulse (605) of the drive frequency (fsw1) or (fsw2) set with the imaging system reference clock (503) at (S1103) or (S1104). Then, a power control signal (502) instructing power supply of the imaging system is sent to the switching power supply (501), and the switching power supply (501) performs power output (607) to the imaging system.

  In (S1107), the system control unit (106) sends an imaging system control signal such as an imaging system reference clock, horizontal scanning signal, vertical scanning signal, etc. to the timing signal generation circuit (104), and an image of the imaging device Start the read operation.

  In (S1108), the phase detection unit (606) reads the switching pulse (605) input to the switching power supply (501) and the readout pulse (608) of the light signal or noise signal of the first imaging device and the second imaging device. Detect (609).

  At (S1109), the phase difference between the two is calculated from the detected phase. FIG. 7 is a view showing the relationship between the phase difference between the switching pulse (605) of the switching power supply (501) and the imaging readout pulse (608) (609) of each imaging device. As shown in FIG. 7, the phase difference between the switching power supply (501) and the readout pulse (608) of the first imaging device is taken as the first phase difference ΔRn_1, and the switching power supply (501) and the readout of the second imaging device A phase difference with the pulse (609) is taken as a second phase difference ΔRn_2.

  In (S1110), the phase detection unit (606) calculates the first phase difference ΔRn + 1_1 and the second phase difference ΔRn + 1_2 at the readout timing of the next row n + 1. The first phase difference ΔRn + 1_1 is a parameter represented by ΔRn + 1_1 = ΔRn_1−β1. Here, β1 is the shorter one from the rising or falling edge of the switching pulse (605) immediately before the rising edge of the horizontal scanning signal in the n + 1th row to the rising edge of the horizontal scanning signal in the n + 1th row. It is a parameter representing time difference. β1 is represented by the following formula (6).

Thd ÷ Tfsw1 = Q remainder α1
α1 = Thd-Tfsw1 × Q
Tfsw1 = 1 ÷ fsw1
If α1 T Tfsw1 / 2, then β1 = α1-Tfsw1 / 2
If α1 <Tfsw1 / 2, then β1 = α1 equation (6)

  Here, Thd is the period of the horizontal scanning signal, and Tfsw1 is the period of the switching pulse (605) determined by the reciprocal of fsw1. The quotient obtained by dividing Thd by Tfsw1 is Q, and the remainder is α1. This is because the period of the switching pulse (605) is not an integral multiple of the period of the horizontal scanning signal, so that a phase shift of α1 occurs in the phase relationship between the two in every row reading. Since β1 represents the shorter time difference from the rising or falling edge of the switching pulse (605) to the rising edge of the horizontal scanning signal in the n + 1th row, α1 is larger than the half cycle of the switching pulse (605) And the half cycle of the switching pulse (605).

  On the other hand, when α1 is smaller than the half cycle of the switching pulse (605), β1 = α1. In the present embodiment (S1102), the relational expression is shown using fsw1 because it is selected to be driven by two imaging elements, but one imaging element may be selected. When it is selected in (S1102) that imaging is performed by one imaging device, β2 is expressed by the following equation (7).

Thd ÷ Tfsw2 = Q remainder α 2
α 2 = Thd − Tfsw 2 × Q
Tfsw2 = 1 ÷ fsw2
If α2 T Tfsw2 / 2, β2 = α2-Tfsw2 / 2
If α2 <Tfsw2 / 2 β2 = α2 Equation (7)

  Similarly, the second phase difference ΔRn + 1_2 is represented by ΔRn + 1_2 = ΔRn_2-β1.

  In (S1111), it is determined whether or not the relationship | ΔRn + 1_1 | ≦ X holds. Here, X is a value taking into consideration the influence of frequency accuracy variation due to the peripheral environment of the spike width of the switching power supply (501) and manufacturing variation of the components constituting the hardware.

  Here, ΔRn + 1_1 is compared with X in order to determine whether or not the readout timing of the imaging element in the next row n + 1 is overlapped with the spike region because a sharp power supply voltage fluctuation occurs in the spike region. . If the relational expression holds, there is a possibility that the switching timing of the switching power supply (501) and the readout timing of the first imaging device (101) may overlap in the reading of the next row n + 1, so (S1112) Transition.

  On the other hand, if the relational expression does not hold in (S1111), the timing of the first image sensor (101) does not need to be corrected by changing the switching frequency (S1117).

  In (S1112), it is determined whether or not the relationship | ΔRn + 1_2−Δt | ≦ X holds. Here, Δt is a parameter representing a predetermined phase correction amount of the switching pulse (605). For example, Δt is a correction amount that can be shifted by the spike width of the switching power supply (501) or more. This is because the switching power supply (501) generates steep power supply voltage fluctuation corresponding to the spike width at the switching timing, and when the read operation is performed in this region, horizontal stripe noise is generated. Therefore, in order to control so as not to perform the read operation in the region where the sharp power supply voltage fluctuation occurs, the phase correction for the spike width or more is performed.

  As the relational expression of (S1112), in order to avoid superimposition of the readout timing of the first imaging device (101) and the switching pulse of the next row n + 1, as a result of correction by Δt, the switching timing and the second It is determined whether the readout timing of the imaging element (102) does not overlap. When the relational expression holds, the timing shifts to (S1113) because the two timings overlap.

  In (S1113), the system control unit (106) sets the phase of the switching pulse (605) in the n-th row by a multiple of the phase correction amount Δt so that the switching timing and the readout timing of the second imaging element (102) do not overlap. A shift of 2Δt is performed to perform an operation to avoid superposition.

  The content of the calculation is control to correct the phase for 2Δt and switch the original drive frequency back to A by switching the current drive frequency from A to the drive frequency B slightly changing the frequency at a predetermined timing. The drive frequency and the switching timing of the drive frequency will be described using FIG. 9B. First, a period from the S reading completion timing of the nth row of the plurality of imaging elements to the start timing of the S reading or N reading on the next row n + 1th row and the rising or falling phase of the switching pulse 605 is Rsn I assume.

Before the phase control, Rsn has a period of the drive frequency A as Tfa, and a predetermined period for driving at the drive frequency A as TA. Further, regarding Rsn at the time of phase control, the period of the drive frequency B is Tfb, and the predetermined period of driving at the drive frequency B is TB. TA is a period of the cycle Tfa of the drive frequency A, TB is c cycles of the cycle Tfb of the drive frequency B, and a shift time of 2Δt is generated in the TB period. TA and TB are represented by the following equation (8).
TA = Tfa × a
TB = Tfb × c equation (8)

Next, a period from the end timing of the period TB driven with the frequency frequency B to the timing at which the S reading or N reading start timing in the row n + 1 row and the phase of the switching pulse (605) overlap is Tch. Tch is represented by the following equation (9) as a predetermined period b of the cycle Tfa of the frequency A, considering the power supply stabilization waiting time when switching from the frequency B to the frequency A again.
Tch = Tfa × b equation (9)

Further, a period from the completion of the S-reading of the n-th row of the plurality of imaging elements in FIG. 9B to the rising timing of the next switching pulse (605) is X3. Therefore, the period of Rsn is expressed by the following equation (10) using the equations (8), (9) and X3.
Rsn = (Tfa × a) + (Tfa × b) + X3 Formula (10)

However, in equation (10), since the S reading or N reading start timing in row n + 1 row and the phase of switching pulse (605) overlap, in order to shift the phase by adding a phase correction amount of + 2Δt to Rsn It is represented by Formula (11) of.
Rsn + 2Δt = (Tfb × c) + (Tfa × b) + X3 Formula (11)

Therefore, the drive period Tfb of the frequency frequency B is expressed by the following equation (12) using the equation (11).
Tfb = (Rsn + 2Δt−Tfa × b−X3) / c Formula (12)

  Next, the process proceeds to (S1114), and the frequency control unit (601) switches the drive frequency of the switching pulse (605) from A to B to A at a predetermined timing calculated in (S1113), thereby switching the switching pulse (605). The phase is shifted by 2Δt in the next row n + 1. After the phase shift is completed, the process shifts to (S1123).

On the other hand, when the relational expression does not hold in (S1112), the process shifts to (S1115), and the calculation for shifting the phase correction amount Δt by the switching frequency change is performed by the following equation (13).
Rsn + Δt = (Tfb × c) + (Tfa × b) + X3 Formula (13)

Therefore, the drive period Tfb of the frequency frequency B is expressed by the following equation (14) using the equation (13).
Tfb = (Rsn + Δt−Tfa × b−X3) / c Equation (14)

  In (S1116), the frequency control unit (601) shifts the phase of the switching pulse (605) by Δt in the next row n + 1 at the predetermined timing calculated in (S1115). After the phase shift is completed, the process shifts to (S1123).

  On the other hand, when the relational expression does not hold in (S1111), the process shifts to (S1117), and it is determined whether the relation | ΔRn + 1_2 | ≦ X holds. When the relational expression is satisfied, there is a possibility that the switching timing of the switching power supply (501) and the reading timing of the second imaging element (102) may overlap in the reading of the next row n + 1 row (S1118) . If the relational expression does not hold in (S1117), the process proceeds to (S1123) because it is not necessary to perform the phase correction.

  In (S1118), it is determined whether or not the relationship | ΔRn + 1_1−Δt | ≦ X holds. Here, Δt is a parameter representing a predetermined phase correction amount of the switching pulse (605) in the same manner as in the previous term.

  As the relational expression of (S1118), in order to avoid superimposition of the readout timing of the second imaging element (102) of the next row n + 1 th row and the switching pulse, as a result of correction for Δt, the switching timing and the first It is determined whether the readout timing of the imaging element (101) does not overlap. When the relational expression holds, since the timings of the two are superimposed, the process shifts to (S1119).

  In (S1119), the system control unit (106) shifts the phase of the switching pulse (605) by the phase correction amount Δt in the n-th row so that the switching timing and the readout timing of the first imaging device (101) do not overlap. Operation to avoid superposition. The content of the calculation is control to correct the phase by Δt and switch the original drive frequency back to A by switching the current drive frequency from A to the drive frequency B which slightly changes the frequency at a predetermined timing.

  The drive frequency and the switching timing of the drive frequency use the same calculation method as (S1113).

  In (S1120), the frequency control section (601) switches the drive frequency of the switching pulse (605) from A to B to A at the predetermined timing calculated in (S1119), thereby shifting the phase of the switching pulse (605) to the next line Shift by 2Δt on the (n + 1) -th line. After the phase shift is completed, the process shifts to (S1123).

  On the other hand, in (S1118), when the relational expression does not hold, the process proceeds to (S1121), and the phase correction amount Δt by switching frequency change is calculated by the same arithmetic expression as (S1115).

  In (S1122), the frequency control section (601) shifts the phase of the switching pulse (605) by Δt in the next line n + 1 at the predetermined timing calculated in (S1121). After the phase shift is completed, the process shifts to (S1123).

  The flow charts after (S1123) will explain the processing in the case where the imaging of the first imaging device (101) and the second imaging device (102) is completed, or the imaging of one of the imaging devices is performed again.

  In (S1123), it is determined whether the imaging of the first imaging element (101) is completed. If the imaging has been completed, the process shifts to (S1125). On the other hand, if the photographing is not completed in (S1123), the process proceeds to (S1124).

  In (S1125), it is determined whether the imaging of the second imaging element (102) is completed. If the photographing has been completed, the process shifts to (S1134). On the other hand, if the photographing is not completed in (S1125), the process shifts to (S1126).

  In (S1126), it is determined whether the imaging operation is to be performed again by the first imaging element (101). When the photographing operation is not performed again by the first imaging element (101), the process returns to (S1108), and the same processing is performed.

  On the other hand, in (S1126), when photographing with the first imaging element (101) again, the process proceeds to (S1127). In (S1127), whether it is necessary to change the period Δsn1 from the “N1” reading timing of the first imaging element (101) to the “S1 reading” timing accompanying the imaging mode change of the first imaging element (101) Make a decision. If the change is not necessary, the drive frequency of the switching power supply (501) is not changed, and the process proceeds to (S1129), and the read operation of the first imaging element (101) is started.

  On the other hand, in (S1127), when changing the readout cycle of the first imaging element (101), the process proceeds to (S1128). In (S1128), the frequency control unit (601) is set by the system control unit (106) so that the frequency of the switching pulse (605) becomes the drive frequency (fsw1) based on the read timing of the two imaging elements. In (S1129), the readout operation of the first imaging element (101) is started, and the process returns to (S1108), and the same processing is performed.

  On the other hand, in (S1123), when the imaging of the first imaging device (101) is not completed, the process proceeds to (S1124), and it is determined whether the imaging of the second imaging device (102) is completed. Do. If the imaging has been completed, the process proceeds to (S1130). On the other hand, if the photographing is not completed in (S1124), the process returns to (S1108), and the same processing is performed.

  In (S1130), it is determined whether the second imaging element (102) performs the photographing operation again. When the photographing operation is not performed by the second imaging element (102) again, the process returns to (S1108), and the same processing is performed. On the other hand, in (S1130), when imaging with the second imaging element (102) again, the process proceeds to (S1131).

  On the other hand, in (S1131), from the “N2” reading timing of the second imaging element (102) to the “S2 reading” timing accompanying the imaging mode change of the second imaging element (102) accompanying the imaging mode change etc. It is determined whether the change of the period Δsn 2 is necessary. If it is not necessary to change, the drive frequency of the switching power supply (501) is not changed, and the process proceeds to (S1133), and the read operation of the second imaging element (102) is started.

  On the other hand, in (S1131), when changing the readout period of the second imaging element (102), the process proceeds to (S1132). In (S1132), the frequency control unit (601) is set by the system control unit (106) so that the frequency of the switching pulse (605) becomes the drive frequency (fsw1) based on the read timing of the two imaging elements.

  In (S1133), the readout operation of the second imaging element (102) is started, and the process returns to (S1108), and the same processing is performed.

  In (S1134), it is determined whether the power switch is off. If the power switch is not off, the process proceeds to (S1135), and it is determined whether or not the imaging mode has been changed. When the imaging mode is not changed, the presence or absence of the imaging start switch (S1105) is detected, and when the imaging mode is changed, the imaging mode is selected (S1102).

  On the other hand, when the power switch is turned off in (S1134), the process proceeds to (S1136), and the power of the imaging apparatus is turned off.

  In FIG. 9B, as an example, the switching timing and the readout timing of the second imaging element (102) are superimposed on the n + 1th line of the next line, and ΔRn + 1_2 = ΔRn_2−β1 ≒ 0 is shown. Therefore, the drive frequency of the switching pulse (605) is switched at a predetermined timing on the n + 1th line of the next line, and the phase correction control of Δt is performed. By this control, it can be understood that the switching power supply switching timing can be avoided without being superimposed on the “N reading” and “S reading” timings of the two imaging devices.

  In the second embodiment, the switching frequency of the switching pulse (605) is two kinds of A and B. However, the present invention is not limited to this, A and B and C of the timing fine adjustment may be added.

  As shown in FIG. 10, by correcting the switching pulse of the switching power supply (501), the switching timing of the switching power supply (501) and the readout timing of the two imaging devices (101) and (102) are avoided without overlapping. I understand that it is done. Therefore, the difference amounts ΔM and ΔL of the potential levels at the “N reading” and at the “S reading” of the first imaging element (101) and the second imaging element (102) can be reduced. Horizontal stripe noise appearing in an image can be reduced.

  As described above, the switching timing of the switching power supply and the readout timing of the two imaging devices are detected, and the phase of the switching pulse is corrected based on the detection result to read out the two imaging devices at the switching timing of the switching power supply. It is possible to avoid. Therefore, it is possible to suppress the influence of the noise generated by the switching power supply on the captured image and to reduce the horizontal stripe noise appearing in the captured image.

  In the present embodiment, although the imaging device constituting the two imaging elements has been described, the present invention is not limited to this. A configuration using three or more imaging elements may be used.

  In the present embodiment, the phase difference between the two imaging devices is calculated by detecting the switching pulse of the switching power supply. However, the configuration may be such that the power supply output of the switching power supply is detected.

  In this embodiment, the switching pulse of the switching power supply and the readout timing of the two imaging elements are detected every row, but only the first row is calculated, and thereafter the timing when the both overlap is determined by calculation. The correction control may be performed.

  As mentioned above, although the preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  A program executed to realize the imaging device according to the above-described embodiment is supplied from a recording medium such as a semiconductor memory, a magnetic disk, a floppy (registered trademark) disk, or the like. Alternatively, it may be downloaded via a wired or wireless network. The object of the present invention is achieved by a system or computer executing the above program. Therefore, the program itself which realizes the function of the above-mentioned embodiment is also one of the present invention.

100 imaging apparatus 101 first imaging element 102 second imaging element 104 timing signal generation unit 106 system control unit 501 switching power supply 601 frequency control unit 604 phase correction unit 606 phase detection unit

Claims (16)

A plurality of imaging devices for converting an optical image into an electrical signal;
A switching power supply that turns on / off switching elements to generate output voltages of different values from input voltages;
A timing signal generation unit that controls the readout timing of the image sensor;
A phase detection unit that detects switching pulses of the switching power supply and readout timings of the plurality of imaging elements;
A phase correction unit that corrects the switching timing of the switching power supply;
An image pickup apparatus characterized in that the phase correction unit corrects the switching timing of the switching power supply based on the information detected by the phase detection unit. The phase correction amount in the phase correction unit is calculated based on the detection information of the phase detection unit, and is a phase correction amount which does not overlap with the switching pulse of the switching power supply and each readout timing of the plurality of imaging elements. The imaging device according to claim 1.   The imaging apparatus according to claim 2, wherein the phase correction amount is a phase correction amount equal to or larger than a spike width of the switching power supply.   The phase correction amount is calculated based on detection information of one of the imaging devices, and the frequency correction amount is applied when the switching pulse of the switching power supply and the readout timing of the other imaging device do not overlap. However, when superimposing the switching pulse of the switching power supply and the readout timing of the other imaging device, a correction amount different from the phase correction amount is applied. A plurality of imaging devices for converting an optical image into an electrical signal;
A switching power supply that turns on / off switching elements to generate output voltages of different values from input voltages;
A timing signal generation unit that controls the readout timing of the image sensor;
A phase detection unit that detects switching pulses of the switching power supply and readout timings of the plurality of imaging elements;
And a frequency control unit that switches a switching drive frequency of the switching power supply,
The image pickup apparatus characterized in that the frequency control unit corrects the switching timing of the switching power supply by changing the switching drive frequency of the switching power supply based on phase information of the plurality of imaging elements detected by the phase detection unit. . The frequency correction amount in the frequency control unit is a frequency correction amount which is calculated based on detection information of the phase detection unit and which does not overlap with the switching pulse of the switching power supply and each readout timing of the plurality of imaging elements. The imaging device according to claim 5.   The imaging apparatus according to claim 6, wherein the frequency correction amount is a phase correction amount equal to or larger than a spike width of the switching power supply.   The frequency correction amount is calculated based on detection information of one of the imaging elements, and the frequency correction amount is applied when the switching pulse of the switching power supply and the readout timing of the other imaging element do not overlap. The imaging device according to claim 6, wherein a correction amount different from the frequency correction amount is applied when superimposing the switching pulse of the switching power supply and the readout timing of the other imaging element.   The image pickup apparatus has a frequency control unit that controls a drive frequency such that a drive cycle of the switching power supply has a predetermined relationship with a cycle in which light signals and noise signals of the plurality of image sensors are read out. The imaging device according to any one of claims 1 to 5, wherein the imaging device is characterized.   The frequency control unit performs the switching such that an arbitrary multiplication of a common multiple of reciprocals of a time difference between each light signal readout timing of each of the plurality of imaging elements and each noise signal readout timing based on a reference clock of the plurality of imaging elements. The imaging apparatus according to claim 1, wherein a drive frequency of a power supply is generated. The imaging apparatus according to claim 1, wherein the phase detection unit detects the phase for each row, and determines a timing for performing the phase correction based on the detected information. The imaging device according to any one of claims 1 to 5, wherein the phase detection unit detects the phase only in the first row, and determines the timing for performing the phase correction based on the detected information. . The information detected by the said phase detection part is the phase difference information of the switching timing of the said switching power supply, and each read-out timing of these imaging devices, It is characterized by the above-mentioned. Imaging device. The switching timing of the switching power supply detected by the phase detection unit is characterized by detecting any one or more of a power supply output of the switching power supply or a switching pulse inputted to the switching power supply. The imaging device according to any one of 5. Each readout timing of the plurality of imaging elements detected by the phase detection unit is characterized by detecting any one or more of a noise signal readout pulse, an optical signal readout pulse, and a horizontal scanning signal of the plurality of imaging elements. The imaging device according to any one of claims 1 to 5, wherein   The phase correction unit is characterized in that the phase of a reference clock of the plurality of imaging devices input to the frequency control unit is corrected based on the detection information of the phase detection unit, and the switching timing of the switching power supply is corrected. The imaging device according to claim 1.