JP3244726B2 - Imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device such as a video camera.

[0002]

2. Description of the Related Art In recent years, the development of video equipment such as video cameras has been remarkable, and various functions have been automated and operability has been improved. For example, automation of zoom lens equipment, automatic focus control, automatic exposure control, etc. Is essential, and for example, when it comes to automatic exposure control, it is an important factor that determines the quality of a captured image, and in any shooting environment, stable and good automatic exposure control must always be possible. The importance of the automatic exposure control function is extremely high.

FIG. 11 is a block diagram showing a basic configuration of an exposure control system of a general video camera, 101 is a photographic lens optical system, 102 is an iris for adjusting the amount of incident light, 103
Denotes an image pickup device such as a CCD for photoelectrically converting an image formed on the image pickup surface of the image pickup lens by the photographic lens optical system and adjusting the amount of light by an iris to convert the image into an image pickup signal; 104, an image pickup signal output from the image pickup device; A camera signal processing circuit that performs predetermined signal processing on the video signal to convert the video signal into a standardized video signal.
05 is a video signal output terminal, 106 is a motor that drives the iris 102 to change the opening amount, 107 is a motor 106
Drive circuit for controlling the driving of the image pickup device 103
CCD drive circuit 109 for controlling the accumulation, readout, and reset timing of the CCD, and variably controlling the accumulation time (exposure time) to set a desired shutter speed. Reference numeral 109 denotes a level of the luminance signal output from the camera signal processing circuit. The aperture driving circuit 107 evaluates the exposure state based on the
An automatic exposure control circuit (AE circuit) 110 for controlling the driving circuit 108 to optimally control exposure, and a switch panel 110 for receiving an input of a key operation.

The exposure control by the AE circuit 109 will be described. The luminance signal output from the camera signal processing circuit 104 is integrated, and the aperture driving circuit 107 is controlled so that the level falls within a predetermined range. A closed loop for iris control is formed to control the output drive current to vary the iris opening amount, and the drive pulse is switched by controlling the CCD drive circuit 108 in accordance with the key operation of the switch panel 110. And a control system for controlling the exposure time, that is, the shutter speed, by varying the accumulation time of the image sensor 103 to obtain an appropriate exposure state. This accumulation time control is called an electronic shutter. For example, in the case of NTSC, in addition to the usual exposure time of 1/60 second for each screen, 1/100
The light accumulation time can be selected in a plurality of stages from about 1 / 10,000 seconds to about 1 / 10,000 seconds.

In the system configured as described above,
When a high-speed electronic shutter is used, there is an automatic exposure control mode for controlling the aperture mechanism (iris) of the imaging optical system based on each arbitrarily selected set exposure time, that is, for each shutter speed. This is a so-called shutter priority mode. FIG. 12 shows the shutter priority mode, in which the shutter speed on the horizontal axis is selected, and the shutter speed is fixed and the aperture value on the vertical axis is varied.

[0006]

However, in the iris control based on the brightness level of the image pickup signal and the shutter priority mode as in the above-mentioned video camera apparatus, appropriate exposure control is always realized in various photographing environments and photographing conditions. Cannot be performed, and proper exposure control cannot be performed in many cases.

[0007] In particular, in a camera such as a silver halide camera for taking a momentary still image, it is sufficient that exposure control at the moment of taking an image is appropriately performed. However, as in a video camera, a moving image is taken for a long time. In such a case, a video that satisfies these conditions must always naturally follow the changing shooting conditions and shooting environment during shooting, and always perform stable and optimal exposure control. Realization of an exposure control device for a camera is strongly desired.

It is an object of the present invention to provide an automatic exposure control device for a video camera which satisfies all of these conditions and can always perform optimal exposure control regardless of a shooting environment and a shooting situation.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is an imaging apparatus capable of controlling a photographing operation using a plurality of control parameters. Calculating means for dividing the area into areas, changing one of the plurality of control parameters for each of the divided areas, and fixing the values of the other parameters to calculate control information; Control means for controlling the photographing operation on the basis of the above, wherein the arithmetic means has a region in which at least two parameters can be changed at the same time in an adjacent boundary portion of the divided region. .

[0010]

[0011]

[0012]

As a result, a plurality of control parameters can be set, and each parameter can be controlled in accordance with the photographing conditions, so that optimal photographing can always be performed according to the photographing situation and the photographing environment. At the same time, since the parameter to be operated is set in accordance with the photographing situation, the control scale of the control circuit does not increase in each situation, and small-scale and high-speed control can be realized.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an image pickup apparatus according to the present invention.

FIG. 1 is a block diagram showing the configuration of an embodiment in which the image pickup apparatus of the present invention is applied to a video camera. In FIG. 1, reference numeral 1 denotes a photographic lens optical system, 2 denotes an iris for adjusting the amount of incident light, and 3 denotes An image pickup device such as a CCD, which photoelectrically converts an image formed on the image pickup surface of the image pickup surface by a photographic lens optical system and whose light amount is adjusted by an iris to convert the image into an image pickup signal;
Is a double correlation sampling circuit (CDS) for reducing the noise of the charge accumulated in the image sensor, 5 is an AGC circuit for automatically adjusting the gain of the image signal, and 6 is a predetermined signal processing for the image signal output from the AGC circuit 5. A camera signal processing circuit for converting the video signal output from the camera signal processing circuit into a signal suitable for recording on a video tape recorder or the like; Reference numeral 8 denotes a video tape recorder using a magnetic tape as a recording medium.

On the other hand, reference numeral 9 denotes an AGC for dividing an imaged screen into a plurality of screens and extracting an image signal corresponding to an arbitrary area.
A gate circuit that gates the signal output from the circuit,
Reference numeral 10 denotes an integrator for integrating an image pickup signal corresponding to a designated area in the image pickup screen selected by the gate circuit 9 to obtain an average light amount, and 11 denotes a system control circuit for outputting a signal output from the integrator, which will be described later. Is an A / D converter for converting into a digital signal that can be processed by the A / D converter. The selection characteristics of the region designation operation by the gate circuit 9 and the integration operation of the integrator 10 are described later in the system control circuit 13.
It can be arbitrarily set by controlling the output gate pulse and the integral reset pulse, and the detailed processing will be described later.

Reference numeral 12 denotes a CCD drive circuit for controlling the accumulation operation, readout operation, reset operation, etc. of the image pickup device 3, reference numeral 13 denotes an iris motor for driving the iris 2, reference numeral 14 denotes an iris drive circuit for driving the iris motor, and reference numeral 15 A D / A converter for converting a digital iris control signal output from a system control circuit into an analog signal,
Reference numeral 6 denotes an iris encoder constituted by a Hall element or the like for detecting the opening amount of the iris, that is, the aperture value. Reference numeral 17 denotes an amplifier for amplifying the output of the iris encoder 16; The A / D converter converts the output into a digital signal that can be processed by a system control circuit described later.

Reference numeral 19 denotes a data reference table (LUT: Look up table) storing various data for iris control;
An operation unit 20 includes a plurality of operation keys for performing various operations. A D / A converter 21 converts a digital gain control signal output from a system control circuit into an analog control signal and supplies the analog control signal to an AGC circuit. , 22, 23
Converts a digital control signal output from the system control circuit into an analog control signal in order to change or correct various characteristics in the camera signal processing and the image signal processing in accordance with the shooting conditions, respectively.
The D / A converter is supplied to the image processing circuit 7.

Reference numeral 25 denotes a system control circuit constituted by a micro computer for comprehensively controlling the entire video camera system in the present embodiment.

The system control circuit 25 transmits control signals for controlling the characteristics of the camera signal processing circuit 6 and the image signal processing circuit 7 in accordance with the photographing mode operated by the operation section 20, to D / A converters 22, 23. , And controls the gate pulse supplied to the gate circuit 9 in accordance with the photographing mode, and sets a photometric region for detecting the amount of light on the imaging screen. Further, it controls the integration reset pulse supplied to the integrator 10 to control the selection characteristic of the integration operation.

For example, FIG. 2 shows an example in which a photometry area is set on the image pickup screen. FIG. 2 shows an example in which a photometry area is set at the center of the image pickup screen, and signals in this area are mainly exposed. FIG. 9 shows an area setting state of “center-weighted metering” used for control calculation.

This is based on an empirical rule that the probability that the main subject is located almost at the center of the screen is high. In the exposure calculation, the signal inside the central area shown by the solid line is larger than the signal outside the central area. Exposure control is performed by assigning coefficients to increase the weight at the center.

Then, an integrated value corresponding to the photographing mode of the image pickup signal in the photometry area taken in through the gate circuit 9 is taken in, and an iris control signal corresponding to the photographing state is calculated while referring to the data of the LUT 19, In addition to supplying the signal to the iris drive circuit 14 via the D / A converter 15 and the gain control signal to the AGC circuit 5 via the D / A converter 21, the AGC circuit 5 5 and a control signal is also supplied to the CCD drive circuit 12 to control the image pickup device's accumulation time (electronic shutter), readout timing, reset timing, etc. according to the photographing mode and photographing situation. Perform

These various controls are performed by referring to the output of the iris encoder 16 in the photographing mode, various control parameters are calculated and set, and the above-described controls are selectively, simultaneously, or simultaneously. They are executed in appropriate combinations.

As described above, the system control circuit 25
Operates the iris control, the gain control, the drive control of the image sensor (for example, the electronic shutter by the accumulation time control) based on the integral value, or the like, simultaneously or appropriately in combination based on the photographic mode and the iris drive state. By doing so, optimal exposure control is performed for all shooting conditions.

The imaging apparatus according to the present invention has the above-described configuration, and its specific operation will be described below in order.

First, various control parameters used for exposure control in the apparatus of the present invention will be described. (1) Iris Aperture (Parameter P1) The iris control signal output from the system control circuit is converted into an analog signal by the D / A converter 15, and then supplied to the iris drive circuit 14 for current amplification. Then, it is supplied to the iris motor 13 to drive it. Thus, the iris motor 13 controls the aperture state of the iris 2.

Integrator 1 supplied from A / D converter 11
If the integrated value of 0 is larger than the control value specified in the LUT 19, the iris drive circuit 14 is controlled to control the iris motor 13
Is driven in the direction of narrowing down, the amount of incident light is reduced, and as a result, the output level of the integrator 10 is reduced.

On the other hand, when the integrated value supplied from the A / D converter 11 is smaller than the control value specified by the LUT 19, the iris motor 13 is driven in the opposite direction, and the iris 2 is driven. It is controlled to open to increase the amount of incident light and consequently to increase the integral value. (2) shear ivy speed (parameter 2) (see Figure 3) accumulation time setting signal D _t of the imaging device is output in the form of a digital signal from the system control circuit 25, CCD driving circuit 12 receives this as a CCD A pulse for determining various timings is generated to control the accumulation time.

Since the setting method and the setting range of the accumulation time are greatly different depending on the structure of the CCD which is the image pickup device, in this embodiment, a CCD having a structure in which unnecessary charges are discarded to the OFD (overflow drain) during the H blanking period is taken as an example. This will be explained.

FIG. 3 is a diagram for explaining the operation of the CCD. The settable range can be set within the range permitted by the image quality such as the quantity of imaged light and smear if the high speed side is within H blanking. . Substantially 1 / 10,000 seconds. In the case of NTSC, the low-speed side can be set in steps of H blanking cycle (about 63.5 μsec) up to 1/60 second.

As a specific time control method, D _t
Is output from the system control circuit 25, the shutter speed T is determined by the following calculation. . T _NTSC ≒ (262.5-D _t ) * 63.5 μsec. T _PAL ≒ (312.5−D _t ) * 64.0 μsec The CCD driving circuit 12 thus instructed further adds ΔV _sub to V _sub (vertical substrate applied voltage) in order to realize the electronic shutter operation. Is added to change the potential distribution of the charge storage portion by photoelectric conversion, and unnecessary charges are discarded in the direction of the substrate. In this way, an arbitrary shutter speed can be set.

The system control circuit 25
Current shear ivy speed corresponding to the integral value from the A / D converter 11 LUT 19 sacrifices defined the D _t in order to slow down the shear ivy speed if Hayakere than the control value is the current value smaller value It was changed to change to a value greater than the current value of said D _t in order to increase the shear ivy speed as late than the control value defined in LUT19 reversed. (3) Gain (Parameter P3) The D / A converter 21 outputs a gain setting signal for determining the amplification factor of the video signal, and supplies it to the AGC circuit 5.

The AGC gain is set by the AGCC amplifier
The output signal of the DS4 is provided so that appropriate signal processing is performed in the camera signal processing circuit 6 in the next stage.
Conventionally, it has been treated as a part of an iris-based AE loop component, and is not the only one that can be arbitrarily controlled.

In recent years, even when the S / N of the CCD has been improved and the gain of the AGC is increased to increase the gain, the noise of the imaging system has become less noticeable, and the settable range as a control parameter has been expanded.

Since the gain is a parameter having a fast control response in the imaging system, it is a parameter suitable for AE control in a situation where a quick response is required.

If the current AGC gain is larger than the control value specified in the LUT 19 corresponding to the integrated value from the A / D converter 11, the system control circuit 25
Updates the gain set value to reduce the AGC gain. Conversely, if the current AGC gain is smaller than the control value specified by the LUT 25 in accordance with the integrated value from the A / D converter 25, the gain setting value is updated to increase the AGC gain.

According to the present invention, by using the above three parameters, it is possible to maintain an appropriate exposure state of the image pickup system in accordance with a photographing condition and a photographing mode. The exposure control used will be described. First, the setting of the photometry area on the imaging screen that changes according to each exposure control mode will be described.

The subject photographed by the video camera is a place,
It changes variously depending on the environment and shooting conditions at that time.

Therefore, in order to always perform the optimum automatic exposure control in these photographing situations, the setting position of the photometric area in the image pickup screen and the weighting control of the photometric area are appropriately changed to suit the situation. Control is needed.

Therefore, in consideration of the light condition according to the set representative scene, a luminance distribution in the screen is assumed, and A is provided in an area in the screen which provides effective information for determining the exposure amount.
It is necessary to have an automatic photographing mode in which an E (automatic exposure control) operation coefficient is assigned to a large value and a photometric region is set so that the weighting is increased.

According to the present embodiment, as shown in FIG. 4, an example is shown in which the imaging screen is divided vertically into four and horizontally into six, and the entire screen is divided into 24 small areas. Each region is numbered from 1 to 24).

These dividing operations are controlled by the system control circuit 25. The gate circuit 9 is opened and closed by a gate pulse output from the system control circuit 25, and the output of the AGC circuit 5 is controlled. The signal is extracted for each of the regions 1 to 24 and is integrated as an independent value by the integrator 10 for each region.
After being converted into a digital signal by the D converter 11, the digital signal is taken into the system control circuit 25.

In the system control circuit 25, processing is performed in which a weighting coefficient preset in accordance with the photographing mode is added to the integrated value in each of these areas. Note that these processes can be performed by time division processing corresponding to 24 divisions.

FIGS. 5 and 6 each show an example of an imaged screen on which weighting coefficient processing has been performed.

FIG. 5 shows the above-mentioned “center-weighted metering” realized by the 24-split AE system of the present invention.
The weighting calculation coefficients in the areas 8 to 11 and 14 to 17 corresponding to the center of the screen are set to 1.0, and the weighting calculation coefficients in the surrounding areas are set to 0.5, so that AE control is performed with emphasis on the center. . Specifically, if the iris, shutter speed, and gain are controlled based on a value obtained by adding the integrated values of these weighted areas, the above-mentioned weights can be reflected in these controls.

FIG. 6 shows an example of a photometry area suitable for "landscape photography". In general, when performing landscape photography, both the ground and the sky are often simultaneously projected on a screen. In addition, the sky part often has very high brightness compared to the ground part, even if it is slightly cloudy. For this reason, when photographing is performed using the conventional AE control that does not consider the photometric area, a person or the like against the ground or the sky often becomes black due to insufficient light quantity.

In order to eliminate these inconveniences, the weighting coefficients of the areas 1 to 6 at the top of the screen corresponding to the sky are set to 0.0 and substantially ignored, and the coefficients above the center of the screen are set to 0.5.
, And the lower half coefficient of the screen is set to 1.0. By allocating the calculation coefficients in this manner, the AE calculation process can be performed with a weight placed below the knitted fabric corresponding to the ground.

In addition to the above two examples, various AE characteristics can be set by setting a photographing mode according to the photographing situation and appropriately selecting the photographing mode.

Next, the actual program AE control using the above three parameters will be described. As described above, in order to perform shooting suitable for various shooting situations,
Since conventional iris control alone cannot be used, more parameters are prepared in the present invention, and these parameters can be optimally controlled.

FIG. 7 is a program diagram showing the setting of each control parameter by the program in the AE control according to the present invention.

In the figure, the abscissa represents the input parameters serving as the control reference, and the ordinate represents the controlled parameters. That is, the present invention employs a method of controlling a plurality of other control parameters in response to an input parameter value serving as a control reference. Here, the reference input parameter is, for example, the subject illuminance, that is, the luminance level, and the left is high luminance and the right is low luminance.

In the figure, the control reference parameter on the horizontal axis is divided into a plurality of areas (three areas A, B, and C in this embodiment) according to the luminance level, and AE control is performed for each area. Is associated with only one variable parameter. This is shown in the table below the program diagram.

That is, in FIG. 7, the input parameters are divided into areas A, B, and C, and the parameters (P
1), an area B is associated with a parameter (P2), and an area C is associated with a parameter (P3). In each area, only one corresponding parameter changes an output value with respect to an input parameter. Are fixed (FIX).

In the figure, in the area A having the highest luminance, the iris control parameter (P1) is variable and the others are fixed, that is, the exposure control is performed by the iris control, and the shutter speed and the gain are fixed.

In practice, the shutter speed of the video is 1
Since the accumulation and readout operations of the image sensor are performed during the field period, the time is typically 1/60 second, and in the area A, a shutter speed higher than the standard is set.
Since the AGC gain is fixed, the setting is such that when the luminance is high, the iris aperture is increased as much as possible to reduce the depth of field to some extent and to improve the S / N.

In the area B, the parameter (P2), that is, the shutter speed is variable and the others are fixed. The iris is fixed so that the depth of field is constant and the S / N is maintained well without increasing the AGC gain. Settings.

In the area C, the parameter (P3), that is, the gain is variable and the other parameters are fixed. When it is desired to fix the iris and give priority to the depth of field, or when the subject is dark and the iris is opened, Even if the illuminance is insufficient, the setting is adapted.

As described above, if the control parameters are increased to P1 to P3 in order to correspond to a certain photographing situation, and these control parameters are controlled by a program in accordance with the values of the input parameters, usually, naturally, naturally. Complicated arithmetic processing is required, which requires a large-scale microcomputer or the like.

However, according to the present invention, the parameter setting area is divided into a plurality of areas according to the value of the input parameter, and the parameter that varies in each area is one.
By fixing the other, the calculation processing of the fixed parameters is not required, which simplifies the handling of complicated and diverse shooting conditions and the handling of multiple parameters to be controlled. The optimum AE control can be realized without using the computer.

FIG. 8 is a flowchart showing a procedure for controlling the above-mentioned parameters.

In the figure, when control is started, S
At step 1, the power is turned on. When the power is turned on, the process proceeds to step S2, where the contents of the instruction such as the photographing mode selected by the operation unit and the current area on the reference parameter axis in FIG. 7 are confirmed.

Subsequently, the flow proceeds to S3, where the branch destination is determined according to the current area while referring to the instruction contents such as the photographing mode selected by the operation section.

When the area is determined to be A, the process proceeds to S4, where the iris control parameter P1 is calculated.
In step 5, the other parameters P2 and P3 are held at the previous values and fixed.
Proceed to S10.

If the area B is determined in S3, the process proceeds to S6, where the shutter speed control parameter P
2 is calculated, and the other parameters P1 and P3 are held and fixed at the previous values in S7, and the process proceeds to S10.

Similarly, when the area C is determined in S3, the process proceeds to S8 to calculate the gain control parameter P3. Then, in S9, the other parameters P1 and P2 are held at the previous values and fixed. Proceed to.

In S10, the values P1, P2, and P3 of the parameters set by the above-described processing are output from the system control circuit 25, and in S11, the process waits until the next processing time unit comes (in this embodiment, One operation per frame is used as a basic unit).
If N is continued, the flow returns to S1 to repeat the above-described processing, and if power-off is instructed, the processing ends.

As a result, various parameters can be controlled, and exposure control is performed based on these parameters.

As described above, according to the present invention, although the number of variable parameters is set to one and the others are fixed, the number of calculation processes can be reduced.
The normal imaging target is a moving image, and the imaging conditions are constantly changing.

When the output parameters are set in accordance with the input parameters as described above, the management of the system is simplified by controlling only one parameter. The value of the input parameter moves between the areas. At this time, a controlled parameter switching operation occurs, but the manner of change on the screen may vary greatly depending on the parameter. If this change occurs frequently, the screen is expected to be difficult to see. You.

As a countermeasure, it is conceivable to provide a hysteresis at the time of area transition and to suppress the frequency of area transition at a low level. However, there is no effect when switching occurs, and it cannot be a fundamental measure. .

Therefore, in the present invention, FIG.
As shown in (1), the control is performed so that two parameters of the adjacent area are simultaneously changed near the boundary of the area.

In the figure, a boundary portion B sandwiched between broken lines
1 is a boundary region where the parameters P1 and P2 operate simultaneously, and similarly B2 is a boundary region where the parameters P2 and P3 operate simultaneously.

By simultaneously changing the two parameters in this manner, an image change peculiar to each parameter occurs simultaneously and gradually. Therefore, even when a parameter moves between areas, the screen changes. Can be visually visually uncomfortable.

FIG. 10 is a flowchart showing the parameter setting operation including the above-described parameter processing of the area boundary portion.

In the figure, when control is started, S
At step 101, the power is turned on. When it is confirmed that the power is turned on, the process proceeds to step S102, where the contents of the instruction such as the photographing mode selected by the operation unit and the current value of the reference parameter axis in FIG. Check the area.

Then, the process proceeds to S3, where the branch destination is determined according to the current area while referring to the instruction content such as the photographing mode selected by the operation unit.

If it is determined that the area is the area A, the process proceeds to S4 to calculate the parameter P1, and then the inside and outside of the area boundary area B1 is determined in S5. To hold and fix the parameter P2, and if it is within B1, proceed to S107 to
After calculating and updating 2, the process proceeds to S117, in which the parameter P3 is held beforehand and fixed.

If the area B is determined in S103, the parameter P2 is calculated in S108, and the process proceeds to S9 to determine the inside and outside of each of the boundary areas B1 and B2. In step S110, P1 is calculated, and the process proceeds to step S117. After the parameter P3 is pre-held and fixed, the process proceeds to step S120.

If it is within B2, the flow advances to S112 to calculate the parameter P3, and the flow advances to S119, where the parameter P1 is held and fixed.

If it does not belong to B1 or B2,
After pre-holding and fixing the parameter P1 in S111,
In S118, the parameter P3 is fixed, and the process proceeds to S120.

If it is determined in step S103 that the area is the area C, the process proceeds to step S113 to calculate the parameter P3. Then, in step S114, the inside and outside of the area boundary area B1 is determined. , To S116, pre-hold and fix the parameter P2, and if it is within B2, S
After proceeding to 115 to calculate and update P2, S119
To S, after preserving and fixing the parameter P1
Proceed to 120.

At S120, the values P1, P2, and P3 of the parameters set by the above-described processing are output from the system control circuit 25, and at S121, the process waits until the next processing time unit comes (in this embodiment, One operation is used as one basic unit for one frame).
If the power ON is continued, the process returns to S101 to repeat the above processing, and if the power OFF is instructed,
The process ends.

As a result, various parameters can be controlled, and exposure control is performed based on these parameters. Moreover, even if the shooting condition changes, the shooting state of the camera does not unnaturally change, and the optimum control mode can be switched.

[0084]

As described above, according to the imaging apparatus of the present invention, the photographing state is controlled using a plurality of parameters, so that finer control can be performed as compared with the conventional apparatus. Under various photographing conditions, there is an effect that optimal photographing can be performed only by selecting the most photographing mode.

Further, since the single parameter control is performed for each of the reference parameters divided into areas according to the conditions of the photographing environment and the other parameters are fixed, the calculation scale can be reduced and the speed can be increased.

The priority order is set for a plurality of parameters, and a single parameter is controlled for each area of the reference parameter. However, at the time of transition between areas, two adjacent parameters are simultaneously controlled so that the screen is displayed. Switching can be performed so as not to cause a sense of incongruity in the change, and it is possible to reduce the change of the image itself which cannot be removed even with the hysteresis.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration in a case where an imaging device according to the present invention is applied to an exposure control device of a video camera.

FIG. 2 is a diagram showing a photometry area in central partial weight photometry.

FIG. 3 is a diagram for explaining the operation of the electronic shutter.

FIG. 4 is a diagram showing an area division state on an imaging screen according to the present invention.

FIG. 5 is a diagram for describing the setting and weighting of a photometry area of “center-weighted photometry” in the present invention.

FIG. 6 is a diagram for explaining setting and weighting of a photometric area in a “landscape shooting mode” according to the present invention.

FIG. 7 is a program diagram for explaining parameter processing of the present invention.

FIG. 8 is a flowchart for explaining a process for explaining parameter setting in FIG. 7;

FIG. 9 is a program diagram for explaining another example of the parameter processing of the present invention.

FIG. 10 is a flowchart for explaining a process for explaining parameter setting in FIG. 9;

FIG. 11 is a block diagram showing a configuration when a general imaging device is applied to an exposure control device of a video camera.

FIG. 12 is a diagram for explaining a shutter priority mode.

Continuation of the front page (72) Inventor Kyouji Tamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A 1-277221 (JP, A) JP 1-236779 ( JP, A) JP-A-4-273777 (JP, A) JP-A-4-271582 (JP, A) JP-A-4-70277 (JP, A) JP-A-2-56181 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) H04N 5/235 G03B 7/08

Claims (1)

(57) [Claims] 1. An imaging apparatus capable of controlling a photographing operation using a plurality of control parameters, wherein a setting area of the control parameter is divided into a plurality of divided areas, and the plurality of control parameters Calculating means for calculating control information while changing any one of the values and fixing other parameter values; and controlling means for controlling the photographing operation based on the calculation result of the calculating means. An imaging apparatus, wherein the calculation means is provided with an area in which at least two parameters can be changed at the same time in a boundary portion adjacent to the divided area.