JP4164522B2 - Imaging device - Google Patents

Description

  The present invention relates to an image pickup apparatus using an image pickup device such as an interline type CCD capable of both a frame mode in which all vertical pixels are read independently and a field mode in which two adjacent pixels in the vertical direction are mixed and read out About.

  In a still image pickup device such as an electronic still camera, both a frame mode in which all pixels in the vertical direction are read independently using an interline CCD or the like and a field mode in which two adjacent pixels in the vertical direction are mixed and read are used. Mode can be performed. Of these two modes, the frame mode, in particular, has a high vertical resolution and meets the needs of users who desire high image quality.

  On the other hand, in such a still image pickup device, an optical finder using an optical member as a finder has been used more than ever. However, in recent years, the performance of EVF using a liquid crystal display device has been improved, and the still image pickup device has been improved. It has come to be used as a finder.

  Further, as the number of pixels of the image sensor used in the still image capturing apparatus increases, the autofocus (AF) performance is required to have a higher level, and the adjustment variation unit of the focus lens becomes smaller. For this reason, it has become essential to use the output signal of the image sensor itself as a signal for determining focus.

From the above, even in a still image capturing apparatus, it is highly necessary to read out an image sensor before generating a still image and use the read output for EVF and AF.
A conventional example of an imaging apparatus capable of imaging in the frame and field modes from such a situation and compatible with EVF and AF using imaging output will be described below.
FIG. 17 is a block diagram of a conventional digital electronic camera.
In FIG. 17, reference numeral 1 denotes an optical lens for forming an optical image on the image sensor, and includes a focus adjusting focus lens (not shown). Denoted at 2 is a mechanical shutter that serves both as an aperture function and a shutter function. Denoted at 3 is a drive circuit for each part of the mechanical system of the optical lens 1 and the mechanical shutter 2 serving as an aperture. 4 is an image sensor such as a CDD that converts an object image formed by an optical lens into an electrical signal, and 5 is a timing signal generation circuit (hereinafter referred to as TG) that generates a timing signal necessary for operating the image sensor 4. , 6 is an image sensor driving circuit that amplifies a signal from the TG 5 to a level at which the image sensor can be driven, 7 is a pre-processing circuit including a CDS circuit and an amplifier circuit for removing output noise of the image sensor 4, and 8 is A / D converter, 9 is an imaging signal processing circuit, and 10 is a recording medium, such as a PCMCIA standard memory card or hard disk. Reference numeral 11 denotes an interface circuit for recording a signal on the recording medium 10. Reference numeral 12 denotes a system controller (system controller) using a CPU that controls a mechanism and an operation unit, an imaging signal processing unit, and the like. Reference numeral 13 denotes an operation unit for controlling the camera from the outside. Reference numeral 14 denotes a display device used as a viewfinder.

  FIG. 18 is a timing diagram for explaining the operation, and FIG. 19 is a diagram showing a color filter array of the image sensor 4. In this color filter, R, G, and B filters are arranged as shown. Hereinafter, a conventional example will be described with reference to FIGS.

When the photographer starts the photographing operation by operating the operation unit 13, the mechanical drive circuit 3 is driven by the control of the syscon 12 to supply power to each circuit. Next, the aperture / mechanical shutter 2 is opened to an aperture diameter (F5.6 in FIG. 18) set by a photometric means (not shown), and the imaging element is opened.

The exposure of the child 4 is started. Then, the electronic shutter pulse (3) and the readout pulse (4) in FIG. 18 are imaged from the TG 5 via the image sensor driving circuit 6 so that the photo charge is accumulated for the exposure time set by the photometry means. Supply to element 4. As a result, the ODD field output and the EVEN field output are alternately output from the image sensor 4 as shown in FIG. In this case, as shown in FIG. 19, the same color signal component is output from both fields. The signals of fields 2 to 4 in FIG. 18 read out in this way are added to the imaging signal processing circuit 9 via the preprocessing circuit 7 and the A / D converter 8, so that the signals for finder output and The signals are converted into AF control signals and sent to the display device 14 and the system controller 12, respectively. The display device 14 displays the subject being shot, and the system controller 12 detects the in-focus position of the optical lens 1 based on the AF signal. Since various means for detecting the focal position are conventionally known, the description thereof is omitted here.

  At the timing of field 4 shown in FIG. 18, the exposure time by the mechanical shutter 2 is determined by the electronic shutter pulse (3) and the readout pulse (4), and the mechanical shutter after field 4 is closed. After using the electronic shutter and the mechanical shutter 2 together in this way, the signals exposed in the field 4 are read out in the fields 5 and 6, thereby reading out the signal of two fields without time lag when all the pixels are exposed at the same time as the frame signal. be able to. The signal read out from the image pickup device 4 in this way is added to the image pickup signal processing circuit 9 via the pre-processing circuit 7 and the A / D converter 8 to be converted into a predetermined signal format and recorded on the recording medium. Recording is performed on the recording medium 10 via the I / F 11.

  In the above-described conventional example, frame reading with a high vertical resolution is performed during still image recording. In this case, frame reading is also performed in the finder output and the imaging output reading for AF. By doing this, the sensitivity of the image sensor 4 can be made the same at the time of still image recording, at the time of finder output and at the time of AF, and the required exposure amount can be made the same level. There is no need to redo or change the aperture, and the time required for the change can be eliminated.

However, when reading in the frame mode at the time of finder output or AF as shown in the conventional example, the following problems occur.
(1) In the frame mode, the sensitivity is halved compared to the field mode. When the sensitivity is low, the illuminance required by the finder and AF increases accordingly, and the finder and AF do not operate normally under low illuminance where a strobe must be used.
(2) In the operation shown in the conventional example, the signal obtained for each field at the time of finder output and AF shifts in the vertical direction by one line as shown in FIG. 19, so the number of vertical lines is only one field. When outputting to the finder, if the interpolation process is not performed, the video is shifted vertically for each field, resulting in an unintelligible image that gives the viewer an unpleasant feeling.

  An object of the present invention is an imaging apparatus having a mode for sequentially displaying a plurality of field images from an imaging element on a display unit, and a mode for recording a still image acquired by the imaging element on a recording medium. This is to prevent deterioration of the output image inside.

  The imaging apparatus of the present invention uses the signal from the imaging device to perform the first operation for performing focus adjustment, and after the focus adjustment has been completed, under the condition that the focus adjustment is performed in the first operation. Imaging having a second operation of displaying an image on the display unit using a signal from the element and a third operation of recording a still image acquired by the imaging device on a recording medium based on an operation by the operation unit In the apparatus, when the luminance of the subject is equal to or lower than a predetermined level, the exposure amount control in the first operation is closer to the aperture than the exposure amount control in the second operation and the third operation. In addition, exposure amount control means for performing control with a high-speed shutter so that the exposure amount control in the third operation is performed with the same aperture setting as that set in the exposure amount control in the second operation is provided. It is characterized by.

  According to the present invention, the frequency of exposure with the open aperture increases during the AF operation, and the exposure is performed at a shallow depth, so that the AF operation can be performed with higher accuracy.

(First embodiment)
FIG. 1 is a timing chart for explaining the operation sequence of the present embodiment, FIG. 2 is a waveform diagram of each vertical transfer pulse for driving the image sensor 4 at the time of frame reading, and FIG. 3 at the time of field reading. It is.
FIG. 4 is a program diagram for determining the aperture diameter and shutter speed at the time of finder output and AF exposure control, and FIG. 5 is for determining the aperture diameter and shutter speed in exposure control after AF lock. FIG. 6 is a program diagram for determining the aperture diameter and the shutter speed in the exposure control of the main exposure.
Further, FIGS. 7 to 10 are flowcharts for explaining a part of the operation sequence in the present embodiment. FIG. 11 is an image diagram showing an example of the color filter array of the image sensor 4, and is also an explanatory diagram of addition pixels at the time of reading. In this example, a case where a complementary color filter is used is shown. The configuration of the electronic camera is the same as that shown in FIG.

Hereinafter, the present embodiment will be described with reference to FIGS.
As shown at T ₁ in FIG. 1, _first , the output of the image sensor 4 (interline CCD in this embodiment) is read with the aperture / mechanical shutter 2 closed, and the output level is set to the reference black level. To do. This black level is used as a reference signal for removing dark current unevenness of the image sensor 4, or subtracted from the imaging output when calculating the exposure control detection signal to absorb the fluctuation of the black level, thereby more accurately exposing the exposure amount. Used to detect In this case, if the correction item for the purpose of using the black level depends on the photoelectric conversion unit of the image sensor 4, the readout pulse is output and the charge corresponding to the dark current of the photoelectric conversion unit is also read and depends on the vertical transfer unit. If it is only possible to do so, a read pulse is not output.

Next, as shown in T ₂ of the FIG. 1 performs exposure control depending on the AF program diagram of FIG. Basically, it is ideal to perform AF with the aperture close to the open position. Therefore, exposure is first performed with a high-speed shutter at F2.5 (AV2.6) with the open aperture, and the output level of the image sensor 4 at that time and the ideal The luminance level is compared and the exposure amount is changed according to the level ratio.

This operation will be described below with reference to the flowcharts of FIGS.
First, in steps S1 and S2 in FIG. 7, exposure is performed with an EV value of 13.1 (aperture opening F2.5, shutter speed 1/1400), and the image sensor 4 is read out. This reading is performed by vertical transfer pulses V _{1 to} V ₄ shown in FIG. That is, as shown in FIG. 11, field readout is performed in which two adjacent pixels in the vertical direction are mixed and read out, and exactly the same vertical transfer pulse V so that the same pixels are mixed in the ODD field and the EVEN field. ₁ ~V ₄ is supplied from TG5.

By performing reading in such a non-interlaced field mode, the following effects are obtained.
(1) The sensitivity can be improved compared to the frame mode.
(2) With either the complementary color filter array as shown in FIG. 11 or the primary color filter array as shown in FIG. 19, a color video signal can be generated by a single readout signal. For this reason, do not use a particularly expensive memory.

A moving image can be obtained at least in real time.

(3) There is little image quality interference when displayed on a liquid crystal display with a small number of vertical lines.
(4) When used as an AF signal, each field image has no phase shift, and high-speed AF with high accuracy is possible. Further, as shown in FIG. 1a, the shutter speed is cleared by throwing away the charge of the photoelectric conversion unit from the substrate and clearing it using the pulse Vsub for electronic shutter, and from the photoelectric conversion unit to the vertical storage unit. Is determined to be the end of exposure.

  A signal corresponding to the exposure amount is output from the image sensor 4, digitized via the pre-processing circuit 7, the A / D converter 8, and the like, and then applied to the image signal processing circuit 9. Here, the luminance signal integral value in a predetermined area on the screen is obtained and calculated by the system controller 12, and the result is obtained from the aperture diameter and timing generation circuit of the aperture / mechanical shutter 2 via the mechanical drive circuit 3. Control the timing of the electronic shutter pulse. In step S3, the brightness level is compared with the reference signal x. If the brightness level is smaller than the reference signal x, the aperture is left open. If it is greater, the aperture is set to F5.6 and the shutter speed 1/1400 in step S4 again. Perform exposure. It should be noted that the mechanical shutter member also serving as an aperture must wait several tens of milliseconds after the switching is performed until the aperture is stabilized. For this reason, a waiting time until stabilization is provided after each aperture change.

Next, the imaged output luminance signal as a result of the re-exposure is compared with the reference level x in step S5. If the luminance signal level is small, the flow proceeds to step S7 in FIG. If there is, the aperture is set to F16 in step S6, and the process proceeds to step 7 in FIG. In step S7, the exposure time is determined based on the luminance signal level at the previous exposure, and re-exposure is performed. Next, in step S8, based on the output signal at the time of exposure in step S7, | X−luminance level | <Y
If YES, it is determined that the exposure is appropriate, the process proceeds to step S13 in the figure, and the AF operation is started. Further, if NO, in step S9,
New exposure time = (old exposure time x (X / brightness level))
The exposure is controlled by controlling the shutter speed so that the luminance level matches the reference level.

  Next, in step S10, it is confirmed whether or not the exposure time derived in step S9 is within the program diagram shown in FIG. 4. If the exposure time is within the range, re-exposure is performed in step S11 with the new exposure time, and the level again. Compare. If it is out of the program diagram range, the aperture is changed in step S12 and the exposure time is recalculated, and then re-exposure is performed.

  As shown in FIG. 4, the program diagram has hysteresis. For example, with an aperture F5.6, the exposure amount is controlled to a shutter speed up to EV12.6, and if it is still dark, the aperture is changed to F2.5. In F2.5, even if EV is 12.6 or greater, the aperture value is not increased, and the aperture diameter is changed only when EV is 13.6 or greater. By doing so, the adjustment of the exposure amount is completed without frequently changing the aperture setting. Particularly in the control of a shutter member that also serves as an aperture as in the present embodiment, it takes time for the aperture value to stabilize, so it is important to make settings so that the aperture does not change frequently as described above. It is.

In the above embodiment, the calculation is performed based on the luminance signal generated from the imaging output for one screen, but this may be used as the average level of the luminance signal of the imaging output for several times. By doing so, it is possible to perform exposure adjustment and AF adjustment appropriately, minimizing the influence when something other than the target subject suddenly jumps into the screen.

Note that the exposure amount is determined depending on the AF program diagram of FIG. 4 during the period of T ₂ next to T ₁ of FIG.

Since the exposure level at which AF operation is possible is obtained by the above operation, the AF operation for detecting the focal point is started next.
First, AF control is started in step S13 of FIG. Since various methods are conventionally known for the control method, description thereof is omitted here. In step S14, it is confirmed whether the focus is in focus (that is, AF control is completed) during the AF control. If the focus is not in focus, the brightness level is compared with the reference level in step S15. At this time, if the difference between the two levels is smaller than the predetermined value, AF is possible, so the process returns to step S13 and the AF operation is continued. If it is larger, it is determined that AF is impossible and appropriate exposure is set through steps S16 to S20. After the correction, the AF control is restarted. However, the predetermined value Z used in step S15 is sufficiently larger than the predetermined value Y.

  This is because when the AF operation becomes possible, changing the exposure amount in the middle is detrimental to the detection of the in-focus point, so when the focus lens scan starts, the exposure level will continue until the scan is completed. This is because a better result can be obtained if is fixed. By fixing, if the brightness level fluctuates due to a change in the imaging range or the like, if there is no effect on the AF focus detection value, quick and accurate AF control becomes possible.

  The predetermined value Y used in step S20 is set to the same value as the predetermined value Y in step S8, and hysteresis is given to the corresponding level of the start / end of adjustment. In this way, the exposure adjustment is restarted only when the amount of light from the light source has changed greatly and the AF level has become impossible at all. Once exposure readjustment is started, the appropriate exposure can be accurately set. It becomes possible.

Next, the operation at the timing of T ₃ in FIG. 1 will be described. After the AF lock is achieved at the end of T ₂ , at T ₃ , exposure control is performed depending on the post-restriction program diagram of FIG. In this case as well, reading is performed in the non-interlaced field mode, so that the effects (1) to (3) can be obtained. Hereinafter, the operation in the period T ₃ will be described with reference to FIG.
First, in step S21, based on the previous exposure amount and the luminance level at that time, the aperture and exposure time are set based on the aperture program diagram of FIG.

  Next, in step S22, the difference between the luminance level of the output of the image sensor 4 exposed by the setting and the reference value X is derived, and the level is compared with a predetermined value Y. If the difference is greater than or equal to Y, it is determined that the exposure is not proper, and the process returns to step S21 to change the exposure control based on the value again. If the difference is less than Y, it is determined that the exposure is appropriate, and the process proceeds to step S23 to confirm the pressing of the second release switch SW2 of the release button (not shown) on the operation unit. If the second release has not been pressed, the process returns to step S21 to confirm the exposure again, and if it has been pressed, the process proceeds to the main exposure in step S24. As described above, according to the present invention example, the appropriate level is confirmed at least once after the above-mentioned narrowing before the main exposure regardless of the pressing timing of the second release button.

It will shift to the exposure timing of T ₄ through T ₅ in FIG. 1 as described above. In this exposure, as shown in FIG. 1, the exposure is performed between the electronic shutter and the mechanical shutter, and the mechanical shutter is completely closed during the period T _5. The pixel signals are sequentially read out from the frame. Vertical transfer pulses V ₁ ~V ₄ for driving the imaging device 4 at this time has a waveform as shown in FIG. 2, for example. Of course, as shown in FIG. 3, the ODD field and the EVEN field may be driven with the same waveform. Up

As described above, the main exposure shooting is performed immediately after pressing the second release (that is, exposure adjustment is not performed after pressing), so that the time from the second release to the main exposure can be shortened as much as possible. Time release lag can be greatly reduced.

  The exposure control during the main exposure is determined by the program diagram of FIG. 6, but since FIG. 6 corresponds to the main exposure and frame reading is performed, the sensitivity is set to 1/2 of the field mode. For this reason, the exposure amount is two times that in the field mode, resulting in proper exposure.

Each program diagram of FIGS. 4 to 6 and its application rule used for the exposure control has the following characteristics.
(1) The program diagram of FIG. 4 has a wider range of brightness that can be photographed with an open aperture than the main exposure program diagram of FIG. 6 and the aperture program diagram of FIG.
(2) The program diagram of FIG. 4 has a smaller number of aperture switching settings than the program diagrams of FIGS. That is, in FIG. 4, the aperture setting is 3 systems, but in FIGS. 6 and 5, there are 5 systems.

(3) In FIG. 4, the range in which the brightness is overlapped and covered between the apertures is larger than that in FIG.
(4) The minimum TV value for each aperture in FIG. 4 is characterized by being larger by a predetermined amount than the minimum TV value for the same aperture in FIG.

(5) When the exposure according to the program diagram of FIG. 4 is shifted to the exposure according to the program diagram of FIG. 5 and there are two types of apertures that can realize the exposure amount obtained in FIG. Start from.
(6) The program diagram for main exposure in FIG. 6 is obtained by shifting the shutter speed by just the sensitivity of field readout and frame readout with respect to the program diagram after focusing in FIG.
That is, at the same aperture, the maximum exposure amount is smaller in FIG. 6 by one EV stage. (In FIG. 5, the shutter speed is 1/30 to 1/500 in the case of F2.5, but in FIG. 6 it is 1/15 to 1/250 in the case of F2.5.) In this embodiment, the frame and field Since the sensitivity ratio is 1: 2, this setting is used. When the sensitivity ratio is different, the exposure program diagram is changed according to the ratio.

By constructing the program diagram as described above, the following effects can be obtained.
First of all, the absolute exposure can be easily detected by performing exposure control based on the program diagram. Therefore, the aperture and shutter speed for proper exposure control can be obtained immediately from the calculated values and optimized for high speed. Exposure can be performed. This is particularly effective in the case of still image shooting or shooting using a separate light source such as a strobe as compared with the camcorder iris system.

Furthermore, the effect corresponding to each item of said (1)-(6) is shown below.
(1) The frequency of exposure with the wide aperture increases during the AF operation, and the exposure is performed at a shallow depth, so that the AF operation can be performed with higher accuracy.
(2), (3) The frequency at which the aperture is switched during the AF operation is reduced, and the waiting time for switching is reduced, so that the total time is saved.
(4), (5) It is possible to prevent the aperture setting after AF lock from being opened further toward the aperture setting during AF adjustment.
As a result, since the aperture is not further opened from the position at the time of focus adjustment, it is possible to perform aperture imaging and still image imaging without degrading the in-focus state.
(6) It is possible to make the aperture setting in the exposure after the aperture stop the same as the aperture setting in the main exposure.

Therefore, there is no need to change the aperture setting after pressing the second release, time can be saved, and no error occurs due to aperture switching, so that more accurate exposure control can be performed.

(Second Embodiment)
In the first embodiment, the image quality of the output image is deteriorated during aperture setting switching. In order to solve this problem, in this embodiment, as shown in FIG. 12, a memory 15 is provided, and image data before switching the aperture setting is stored in the memory 15. During the aperture switch, the image data stored in the memory 15 is output to the display device 14.
The output period of the memory 15 may be set in anticipation of the scheduled stop time of aperture setting, or after confirming that the luminance level of the output signal of the image sensor 4 has reached an appropriate level, the output of the memory 15 May be terminated. If the control load of the present embodiment is relatively large and the CPU for control in the system controller 12 is overloaded, it may be output from the memory 15 at the end of T ₂ in FIG. 1, that is, after AF lock. . This is because during AF adjustment, in addition to the influence of aperture switching, image quality deterioration due to focus adjustment is also overlapped, so in any case the quality of image quality is not sufficient.

(Third embodiment)
In the first and second embodiments, the shutter / stop diaphragm is used. Of course, a separate dedicated diaphragm or shutter may be used. According to the present embodiment, it is possible to use a high-speed shutter with a higher curtain speed and a highly accurate aperture.

(Fourth embodiment)
In the first embodiment, the minimum TV value for each aperture in the program diagram of FIG. 4 is set to be a predetermined amount larger than the minimum TV value of the same aperture in FIG. A program diagram in which the longest shutter speed at the aperture of F16 in FIG. 4 is further increased may be used. This is because with F16 to F8 having a sufficiently small aperture diameter, the depth of field is sufficiently deep, and even when the focus is adjusted with F16 and the image is taken with F8, the deterioration in image quality is not noticeable.
According to the present embodiment, as shown in FIG. 13, the minimum exposure amount at the diaphragm F16 can be set to EV 14.8, and a sufficient margin for hysteresis can be obtained. Can be less.

(Fifth embodiment)
In each of the above embodiments, when there is a large change in the luminance signal during exposure level adjustment and AF adjustment, this sudden change occurs when the change in the luminance signal returns to the original level even in a short period of time. It is also possible to perform exposure adjustment and AF adjustment while ignoring the output signal during the period.
14 to 16 are examples of flowcharts for realizing the present embodiment. Steps S7 to S10 and S12 in FIG. 14 are substantially the same as steps S7 to S11 in FIG. In FIG. 14, when the absolute value of the difference between the reference value X and the output signal luminance level is larger than the predetermined value Y in step S8, first, 1 is added to the variable N in step S25. Note that an initial value 0 is preset for N.

Subsequently, the magnitude of N and the constant A are compared in step S26, and if N is small, reexposure is performed in step S7 without changing the exposure amount from the previous time because it is a short-term abnormal value. On the other hand, if N is large, it is recognized that the actual subject condition has changed, and the exposure time is recalculated in step S9. After setting N = 0, the process proceeds to steps S7 and S10 in the same manner as in the first embodiment. Return.
If the luminance level is within the predetermined range in step S8, N = 0 is set in step S27, and then the process proceeds to the next sequence (step S21 in FIG. 10). With the above operation,

Even when a non-subject has entered the screen for a short period of time, it is possible to perform exposure setting without the influence.

Further, steps S13 to S20 in FIG. 15 are the same as steps S13 to S20 in FIG.
In FIG. 15, when the absolute value of the difference between the reference value X and the output signal luminance level is larger than the predetermined value Z in step S15, first, 1 is added to the variable N in step S28. Note that an initial value 0 is preset for N. Subsequently, N is compared with a constant A in step S29, and if N is small, it is a short-term abnormal value, so that re-exposure is performed in step S30 without changing the exposure amount from the previous time, and the luminance level is again determined in step S15. Determine the size of. On the other hand, if N is large, it is recognized that the actual subject condition has changed, and the exposure time is recalculated in step S16. After setting N = 0, the process returns to step S13 via steps S13 to S20.

  According to the operation of FIG. 15, even when the abnormality of the luminance level is detected and the AF control is exited, if the value further returns to the original value even if it ends in a short period of time, the data in between Since it is configured to continue AF operation without ignoring exposure and changing exposure control, AF adjustment can be performed without being affected even if a subject other than the target subject suddenly jumps into the screen. Can be done.

Steps S21 to S24 in FIG. 16 are the same as steps S21 to S24 in FIG. However, in step S31, the fact that the initial value Y0 is set to the variable Y in step S21 was specified.
In FIG. 16, when the absolute value of the difference between the reference value X and the output signal luminance level is smaller than the predetermined value Y in step S22, it is considered that the exposure level is appropriate. The constant a is added. By giving hysteresis to the determination level in this way, the frequency of No in the subsequent determination in step S22 is reduced, and it is possible to prevent an unsightly image from being frequently changed by changing the exposure level.

On the other hand, when the absolute value of the difference between the reference value X and the output signal luminance level is larger than the predetermined value Y in step S22, first, 1 is added to the variable N in step S32. Note that an initial value 0 is preset for N. In step S33, N is compared with a constant A. If N is small, it is a short-term abnormal value. In step S34, re-exposure is performed without changing the exposure amount from the previous time. Determine the size of. On the other hand, if N is large, it is recognized that the actual subject condition has changed, and the process proceeds to an operation for changing the exposure control. At this time, in this embodiment, the variable Y is Y = Y0 + a in the previous operation. Therefore, Y = Y0 is returned to step S35. After returning to Y0, the process returns to step S21 again to reset the exposure level.
According to the operation shown in FIG. 16, it is possible to appropriately adjust the exposure without being influenced even when a non-target subject suddenly jumps into the screen.

It is a timing chart which shows the operation | movement by the 1st Embodiment of this invention. It is a timing chart which shows the operation | movement by the 1st Embodiment of this invention. It is a timing chart which shows the operation | movement by the 1st Embodiment of this invention. It is a program diagram used for a 1st embodiment. It is a program diagram used for a 1st embodiment. It is a program diagram used for a 1st embodiment. It is a flowchart which shows operation | movement of 1st Embodiment. It is a flowchart which shows operation | movement of 1st Embodiment. It is a flowchart which shows operation | movement of 1st Embodiment. It is a flowchart which shows operation | movement of 1st Embodiment. It is a block diagram which shows the color filter arrangement | sequence of the image pick-up element used by this invention. It is a block diagram which shows the 2nd Embodiment of this invention. It is a program diagram used in the third embodiment of the present invention. It is a flowchart which shows the operation | movement of the 5th Embodiment of this invention. It is a flowchart which shows the operation | movement of the 5th Embodiment of this invention. It is a flowchart which shows the operation | movement of the 5th Embodiment of this invention. It is a block diagram of the imaging device by the conventional and 1st Embodiment of this invention. It is a timing chart which shows operation | movement of the conventional imaging device. It is a block diagram which shows the color filter arrangement | sequence used with the conventional imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical lens 2 Shutter combined shutter 4 Imaging element 9 Imaging signal processing circuit 12 System controller 13 Operation part 14 Display apparatus 15 Memory

Claims (2)

A first operation for performing focus adjustment using a signal from the image sensor, and a signal from the image sensor under the condition in which the focus is adjusted in the first operation after the focus adjustment is completed. An imaging apparatus having a second operation for displaying an image on a display unit and a third operation for recording a still image acquired by the imaging element on a recording medium based on an operation by an operation unit;
When the luminance of the subject is below a predetermined level, the exposure amount control in the first operation is closer to the full aperture and the high-speed shutter than the exposure amount control in the second operation and the third operation. And exposure amount control means for performing control so that the exposure amount control in the third operation is performed with the same aperture setting as that set in the exposure amount control in the second operation. apparatus.   2. The imaging apparatus according to claim 1, wherein in the first and second operations, pixels of a plurality of lines of the imaging device are added and readout is performed non-interlaced between a plurality of fields.

Images