JP2000354196A - Image pickup device, exposure control method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain optimum exposure control by changing only a predetermined coefficient without remarkably increasing number of parts so as to realize free selection of a center-weighted average photometry, a peak photometry or a whole surface average photometry in the case that a photographer intentionally selects a photographing mode depending on a photographed scene. SOLUTION: The image pickup device is provided with a photographing mode changeover circuit 101 that discriminates whether the photographing mode is a center-weighted average photometry, a peak photometry or a whole surface average photometry and an AE control signal arithmetic circuit 102 that multiplies a coefficient in response to the photographing mode selected by the photographing mode changeover circuit 101 with photometry values calculated by a luminance signal detection circuit 405 and a luminance signal peak value detection circuit 406 and sums them to generate the photometry value and controls an iris 401 and an automatic gain control AGC circuit 403 so that a level of the photometry value is within a prescribed range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image pickup apparatus, an exposure control method, and a storage medium, and more particularly, to an image pickup apparatus, an exposure control method, and a storage medium suitable for application to a camera-integrated VTR or the like.

[0002]

2. Description of the Related Art Hitherto, means for automatically controlling exposure in an image pickup apparatus such as a video camera has been devised. The exposure control of the imaging apparatus in the conventional example will be described below with reference to a block diagram of the conventional example in FIG. 10, a flowchart of the conventional example in FIG. 11, and a supplementary diagram of the conventional example in FIG.

In the circuit configuration shown in FIG.
1 controls the amount of incident light. CCD (Charge Coupled D
evice) and the like, photoelectrically converts the image whose light amount is adjusted by the iris 401 into a video signal. AGC (Automatic Gain Controller) circuit 40
Reference numeral 3 designates that the video signal output from the image sensor 402 has a gain. The camera signal processing circuit 404 performs predetermined signal processing on the video signal to convert it into a standardized video signal. The luminance signal detection circuit 405 divides the imaging screen into a plurality of screens, applies a plurality of gates to the video luminance signal obtained from the AGC circuit 403 to extract an image signal corresponding to an arbitrary region, and An average luminance (photometric value) is obtained by integrating the video luminance signal corresponding to the designated area.

[0004] A luminance signal peak value detection circuit 406 divides the imaged screen into a plurality of screens, and applies a plurality of gates to the video luminance signal obtained from the AGC circuit 403 to extract an image signal corresponding to an arbitrary area. In addition, an area having the highest luminance on the imaging screen is selected, and a video luminance signal corresponding to the designated area is integrated to obtain an average light amount (photometric value). The AE control signal calculation circuits 2 and 407 calculate a photometric value for actually controlling the AE from the plurality of photometric values detected by the luminance signal detecting circuit 405 and the photometric value detected by the luminance signal peak value detecting circuit 406. AE control is performed by calculation. The configuration is as described above.

[0005] In this specification, the AE control signal operation circuit of the conventional example and an AE control signal operation circuit of an embodiment of the present invention to be described later are partially different in processing contents (detailed in the embodiment). The AE control signal operation circuit of the conventional example is 2 and the AE control signal operation circuit of the embodiment of the present invention described later is 1
Is added separately from the code assigned to the arithmetic circuit.

FIG. 11 shows the AE control signal operation circuits 2.4.
It is a flowchart showing the processing contents in 07. Step S501: The photometric value of the upper part of the screen (portion C in FIG. 12) detected by the luminance signal detection circuit 405 is set to Ys1. Step S502: The photometric value of the peripheral portion of the screen (portion B in FIG. 12) detected by the luminance signal detection circuit 405 is set to Ys2. Step S503: The photometric value at the center of the screen (A in FIG. 12) detected by the luminance signal detection circuit 405 is set to Ys3. Step S504: Peak value detected by the luminance signal peak value detection circuit 406 (part D in FIG. 12)
Is taken as Ys4. Step S505: Step S501, Step S502, Step S503, Step S5
04, Ys1, Ys2, Ys3, Ys
4 is a predetermined center-weighted average metering ratio (α: β:
.gamma.:. delta.), and each is added to calculate a photometric value. The flow is as described above.

Next, a specific operation of the conventional example will be described with reference to FIG.
0, FIG. 11, and FIG.

An optical image is photoelectrically converted by an image sensor 402 through an iris 401 of the image sensor. Image sensor 402
The output video signal is input to the AGC circuit 403, has a predetermined gain, and is sent to the camera signal processing circuit 404. The image luminance signal for controlling the exposure is input to the luminance signal detection circuit 405 using the image luminance signal before being input to the camera signal processing circuit 404.

The luminance signal detection circuit 405 applies a plurality of gates to the video luminance signal, integrates the video luminance signal corresponding to a designated area on the image pickup screen, and obtains an average light amount. For example, the image luminance signal at the center of the screen (part A in FIG. 12) is integrated to obtain the average light amount (photometric value), and the image luminance signal at the peripheral part of the screen (part B in FIG. 12) is integrated. To determine the average amount of light (photometric value)
The image luminance signal at the top of the screen (portion C in FIG. 12) is integrated to determine the average light amount (photometric value). Then, each is input to the AE control signal operation circuit 2 · 407.

On the other hand, the video luminance signal is also input to a luminance signal peak value detection circuit 406. In the luminance signal peak value detection circuit 406, the horizontal direction is H1 to H8 and the vertical direction is V1 to V8 on the imaging screen as shown in the supplementary diagram of the conventional example in FIG.
As shown by the dotted line, the image is divided into a plurality of screens, gated, the area with the highest luminance on the imaging screen is selected, the video luminance signal corresponding to the specified area is integrated, and the average light quantity is obtained. (Eg, (H3, V4) in FIG. 12)
D part). Then, each is input to the AE control signal operation circuit 2 · 407.

In the AE control signal calculation circuit 2 · 407, the photometric value at the upper part of the screen is set to Ys1 (step S501 in the flowchart of FIG. 11), and the photometric value at the peripheral part of the screen is set to Ys2.
(Step S50 in the flowchart of FIG. 11)
2) The photometry value at the center of the screen is set to Ys3 (step S503 in the flowchart of FIG. 11), and the photometry value at the peak portion of the screen is set to Ys4 (step S504 in the flowchart of FIG. 11). Then, the photometric value is calculated by adding (step S505 in the flowchart of FIG. 11). In the conventional example, Ys1, Y
Assuming that the addition ratio of s2, Ys3, and Ys4 is α: β: γ: δ, the photometric value is Ys = Ys1 × α + Ys2 × β + Ys3 × γ + Ys4 ×
δ.

Exposure control is performed so that the level of the photometric value falls within a predetermined range.
By controlling the iris 401 and the AGC circuit 403.

[0013]

However, in the automatic exposure control method described in the above-mentioned conventional example, particularly when it is desired to take a picture of a main subject exposed to a spotlight at a wedding ceremony, a stage or the like, such a subject is located at the top of the screen. In addition, since the brightness at the periphery of the screen is lower than that at the center of the screen, even if the main subject at the center of the screen is controlled to an appropriate exposure by adding the peak metering value to the center-weighted average metering, the main subject at the center of the screen is not The problem of overexposure remains. This problem can be solved by setting the photometry method to peak photometry.

Further, in the automatic exposure control method described in the above-mentioned conventional example, when it is desired to change the angle of view of a camera in a horizontal direction for a subject having a high contrast, the subject at the center of the screen is weighted by exposure. For this reason, while the angle of view is changed in the horizontal direction, there is a problem that the exposure responds more quickly than necessary and the brightness changes fuzzy. This problem can be solved by setting the photometry method to the entire surface average photometry. Like this,
With the current automatic exposure control method, it is difficult to realize a photometric method that satisfies all photographing scenes, and there is a problem that there are photographing scenes that are inevitably weak.

The present invention has been made in view of the above points, and when a photographer intentionally switches a photographing mode in accordance with a photographing scene, a predetermined coefficient can be set without greatly increasing the number of parts. Only an image pickup device, an exposure control method, and a storage medium capable of freely selecting a center-weighted average metering, a peak metering, or an entire surface average metering and performing optimal exposure control. With the goal.

[0016]

In order to achieve the above object, the present invention according to claim 1 has a function of controlling the amount of transmitted light of an imaging optical system, a function of performing photoelectric conversion of transmitted light, and a function of performing a predetermined operation on an imaging screen. An imaging device having a function of calculating a photometric value of an area, wherein a photographing mode switching unit that enables a photographer to intentionally switch a photographing mode, and a photometric value of a plurality of predetermined areas on the imaging screen. A photometric value generating unit that adds a value obtained by multiplying a coefficient corresponding to the image capturing mode selected by the image capturing mode switching unit to generate a photometric value; and the transmitted light amount according to the photometric value generated by the photometric value generating unit. And control means for controlling the control system.

In order to achieve the above object, the present invention according to claim 2 further comprises an iris adjusting means for controlling the amount of transmitted light of the imaging optical system, and a photoelectric conversion means for accumulating the transmitted light and performing photoelectric conversion. Means and a first average light amount calculation for dividing the image pickup screen into a plurality of parts, applying a gate to the image luminance signal, and integrating an image luminance signal corresponding to a designated area on the image pickup screen to calculate an average light amount thereof A second means for dividing the imaging screen into a plurality of parts, gating a video luminance signal, integrating a video luminance signal corresponding to an area having the highest luminance on the imaging screen, and calculating an average light amount thereof. Average light amount calculating means.

According to a third aspect of the present invention, there is provided the image capturing apparatus according to the third aspect, wherein the image capturing mode switching means determines whether the externally designated image capturing mode is a center-weighted average metering mode effective for capturing an ordinary object. , To determine whether it is a peak metering mode effective for shooting a subject irradiated with spot light or an overall average metering mode effective for shooting panning in the horizontal direction,
The photometric value generation unit is configured to determine the photometric value calculated by the first average light amount calculation unit and the second average light amount calculation unit by the coefficient according to the selected shooting mode determined by the shooting mode switching unit. Are added to generate a photometric value.

According to a fourth aspect of the present invention, in order to achieve the above object, the coefficient is set in advance to a value corresponding to the center-weighted average metering mode, the peak metering mode, and the overall average metering mode. It is characterized by being.

To achieve the above object, the present invention according to claim 5 is characterized in that it is applicable to a camera-integrated VTR or the like.

In order to achieve the above object, the present invention provides a function of controlling the amount of transmitted light of an imaging optical system, a function of performing photoelectric conversion of transmitted light, and calculating a photometric value of a predetermined area on an imaging screen. An exposure control method applied to an imaging device having a function of performing a shooting mode switching step that allows a photographer to intentionally switch a shooting mode,
A photometric value generating step of adding a value obtained by multiplying a photometric value of a plurality of predetermined areas on the image capturing screen by a coefficient corresponding to the photographing mode selected in the photographing mode switching step to generate a photometric value; A control step of controlling the control system of the amount of transmitted light according to the photometric value generated in the step.

To achieve the above object, the present invention according to claim 7 further comprises an iris adjusting step of controlling the amount of transmitted light of the image pickup optical system, and a photoelectric conversion for accumulating the transmitted light and performing photoelectric conversion. And calculating a first average light amount for dividing the imaging screen into a plurality of parts, gating a video luminance signal, integrating a video luminance signal corresponding to a designated area on the imaging screen, and calculating an average light amount. A second step of dividing the imaging screen into a plurality of parts, gating a video luminance signal, integrating a video luminance signal corresponding to an area having the highest luminance on the imaging screen, and calculating an average light amount thereof. Average light quantity calculation step.

In order to achieve the above object, according to the present invention, in the photographing mode switching step, an externally designated photographing mode is a center-weighted average metering mode effective for photographing a normal subject. In the photometric value generation step, the first average light amount calculation is performed by determining whether the peak photometric mode is effective for photographing the subject irradiated with the spot light or the overall average photometric mode is effective for photographing panned in the horizontal direction. Generating a photometric value by adding a value obtained by multiplying the photometric value calculated in the step and the second average light amount calculating step by the coefficient corresponding to the selected photographing mode determined in the photographing mode switching step. Features.

According to a ninth aspect of the present invention, in order to achieve the above object, the coefficient is set in advance to a value corresponding to the center-weighted average photometry mode, the peak photometry mode, and the overall average photometry mode. It is characterized by being.

To achieve the above object, the present invention is characterized in that the present invention is applicable to a camera-integrated VTR or the like.

In order to achieve the above object, according to the present invention, a function of controlling the amount of transmitted light of an image pickup optical system is provided.
A computer-readable storage medium storing a program for executing an exposure control method applied to an imaging apparatus having a function of photoelectrically converting transmitted light and a function of calculating a photometric value of a predetermined area on an imaging screen, The exposure control method includes: a photographing mode switching step that allows a photographer to intentionally switch a photographing mode; and a photographing mode selected in the photographing mode switching step to a photometric value of a plurality of predetermined regions on the photographing screen. A photometric value generating step of adding a value multiplied by a coefficient according to the mode to generate a photometric value, and a control step of controlling the control system of the transmitted light amount according to the photometric value generated in the photometric value generating step. It is characterized by having.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an imaging device according to an embodiment of the present invention. An imaging device according to an embodiment of the present invention includes an iris 401, an imaging element 402,
GC circuit 403, camera signal processing circuit 404, luminance signal detection circuit 405, luminance signal peak value detection circuit 406, shooting mode switching circuit 101, AE control signal calculation circuit 1
・ 102 is provided. The imaging device according to the embodiment of the present invention is applicable to, for example, a camera-integrated VTR.

The configuration of the main part will be described in detail. A photographing mode switching circuit 101 is used to intentionally switch a photographing mode (see FIG. 7) suitable for a scene to be photographed by the photographer based on the operation of the photographer. Circuit. The AE control signal operation circuits 1 and 102 include a plurality of photometric values detected by the luminance signal detection circuit 405 and a luminance signal peak value detection circuit 4.
The AE control is performed by calculating a photometric value for actually controlling the AE in accordance with the photometric value detected in step 06 and the photographing mode selected by the photographing mode switching circuit 101. The configuration is as described above. In addition, Iris 40
1, the image sensor 402, the AGC circuit 403, the camera signal processing circuit 404, the luminance signal detection circuit 405, and the luminance signal peak value detection circuit 406 have the same configurations as those of the above-described conventional example, which are denoted by the same reference numerals in FIG. The details of each unit have been described with reference to FIG.

FIGS. 2 and 3 show the AE control signal operation circuits 1.1 of the imaging apparatus according to the embodiment of the present invention shown in FIG.
9 is a flowchart showing the processing contents in the second embodiment. still,
Steps S501 to S504 in FIGS. 2 and 3
Has the same processing contents as steps S501 to S504 in FIG. 11 described in the above conventional example, and the details have been described in the conventional example, and a description thereof will be omitted.

The steps newly added to the processing contents of the AE control signal operation circuits 1 and 102 in the image pickup apparatus according to the embodiment of the present invention are as follows. Step S201: The photographing mode switching circuit 101 determines which of the photographing modes is selected from among 1, 2, and 3. Step S202: When the photographing mode 2 is selected in the above step S201, a predetermined coefficient 5 is substituted into α, a coefficient 6 is substituted into β, a coefficient 7 is substituted into γ, and a coefficient 8 is substituted.
Is substituted for δ. Step S203: When the photographing mode 1 is selected in step S201, a predetermined coefficient 1 is substituted into α, a coefficient 2 is substituted into β, a coefficient 3 is substituted into γ, and a coefficient 4 is substituted.
Is substituted for δ. Step S204: When the photographing mode 3 is selected in step S201, a predetermined coefficient 9 is substituted for α, a coefficient 10 is substituted for β, a coefficient 11 is substituted for γ, and a coefficient 12 is substituted for δ. I do. Step S205: Step S501, Step S502, Step S503, Step S5
04, Ys1, Ys2, Ys3, Ys
4 is multiplied by a predetermined photometric ratio (α: β: γ: δ) according to the photographing mode selected in step S201, and further added to calculate the photometric value. The flow is as described above.

FIG. 9 is an explanatory view showing a conceptual example in which the program and related data of the present invention are supplied from a storage medium to the apparatus. The program and related data of the present invention are stored in a storage medium 901 such as a floppy disk or a CD-ROM in the device 90.
2 is supplied by inserting it into the storage medium drive insertion port 903 provided in the storage medium drive 2. Thereafter, the program and the related data of the present invention are temporarily installed on the hard disk from the storage medium 901 and then loaded into the RAM from the storage medium 901, or directly loaded into the RAM without being installed on the hard disk, to thereby obtain the program and the related data Can be executed.

In this case, when the program of the present invention is executed in the image pickup apparatus according to the embodiment of the present invention, the program of the present invention is stored in the image pickup apparatus via a device such as a computer as shown in FIG. By supplying the program and related data, or storing the program and related data of the present invention in the imaging device in advance, the program can be executed.

FIG. 8 is an explanatory diagram showing a configuration example of the storage contents of a storage medium storing the program and related data of the present invention. The storage medium of the present invention stores, for example, volume information 80
1, directory information 802, a program execution file 803, a program-related data file 804, and the like. The program of the present invention is shown in FIGS.
Is a program code based on the flowchart of FIG.

The correspondence between the components in the claims of the present invention and the components of the imaging apparatus according to the embodiment of the present invention is as follows. The photographing mode switching means corresponds to the photographing mode switching circuit 101, the photometric value generating means and the control means correspond to the AE control signal calculation circuits 1 and 102, the iris adjusting means corresponds to the iris 401,
The photoelectric conversion unit corresponds to the image sensor 402, the first average light amount calculation unit corresponds to the luminance signal detection circuit 405, and the second average light amount calculation unit corresponds to the luminance signal peak value detection circuit 406.

Next, a specific operation of the imaging apparatus according to the embodiment of the present invention configured as described above will be described with reference to FIGS.

The optical image is photoelectrically converted by the image pickup device 402 through the iris 401 of the image pickup device. Image sensor 402
The output video signal is input to the AGC circuit 403, has a predetermined gain, and is sent to the camera signal processing circuit 404. The image luminance signal for controlling the exposure is input to the luminance signal detection circuit 405 using the image luminance signal before being input to the camera signal processing circuit 404.

The luminance signal detection circuit 405 applies a plurality of gates to the video luminance signal and integrates the video luminance signal corresponding to a specified area on the image pickup screen to obtain an average light amount. For example, the image luminance signal at the center of the screen (part A in the supplementary diagram of FIG. 4) is integrated to obtain the average light amount (photometric value), and the periphery of the screen (part B in the supplementary diagram of FIG. 4) is obtained. Image luminance signal is integrated and its average light intensity (photometric value)
, And integrates the image luminance signal in the upper part of the screen (the part C in the supplementary diagram of FIG. 4) to calculate the average light amount (photometric value)
Ask for. Each of the AE control signal operation circuits 1
-Input to 102.

On the other hand, the video luminance signal is also input to a luminance signal peak value detection circuit 406. In the luminance signal peak value detection circuit 406, the imaging screen is divided into a plurality of screens as shown by dotted lines H1 to H8 in the horizontal direction and V1 to V8 in the vertical direction as shown in the supplementary diagram of FIG. Then, an area having the highest luminance on the imaging screen is selected, and a video luminance signal corresponding to the designated area is integrated to obtain an average light amount (for example, (H3, V4) in the supplementary diagram of FIG. 4). D
Part). Each of the AE control signal operation circuits 1
-Input to 102.

In the AE control signal calculation circuits 1 and 102, the photometry value at the upper part of the screen is set as Ys1 (step S501 in the flowchart of FIG. 2), and the photometry value at the periphery of the screen is set as Ys2 (step S502 of the flowchart of FIG. 2). The photometry value at the center of the screen is set to Ys3 (step S503 in the flowchart of FIG. 2), and the photometry value at the peak of the screen is set to Ys3.
4 (step S50 in the flowchart of FIG. 2).
4).

On the other hand, the photographing mode switching circuit 101 allows the photographer to intentionally select a photographing mode most suitable for the photographing scene. In the present embodiment, this means a shooting mode in which a photometric method used when performing exposure control is changed. Specifically, a shooting mode (center-weighted average metering) that is effective when shooting a normal subject, a shooting mode (peak metering) that is effective when shooting a subject that is illuminated by spot light,
There are shooting modes (average photometry over the entire surface) that are effective when the camera is intentionally panned in the horizontal direction and shooting is performed. Photographing mode 1 described in step S201 of the flowchart in FIG.
Is described as a center-weighted average metering mode, shooting mode 2 is a peak metering mode, and shooting mode 3 is a full-area average metering mode.

In the photographing mode switching circuit 101,
Whether the selected shooting mode is shooting mode 1 (center-weighted average metering mode) or shooting mode 2 (peak metering mode)
Or the photographing mode 3 (entire average photometry mode) (step S20 in the flowchart of FIG. 2).
1).

When the photographing mode 1 (center-weighted average photometry mode) is selected in the photographing mode switching circuit 101, the coefficient 1 is assigned to α, the coefficient 2 to β, the coefficient 3 to γ, and δ.
Is assigned to the coefficient 4 (step S203 in the flowchart of FIG. 3). When the photographing mode 2 (peak metering mode) is selected in the photographing mode switching circuit 101, a coefficient 5 is set to α, a coefficient 6 is set to β, a coefficient 7 is set to γ,
The coefficient 8 is substituted for δ (step S202 in the flowchart of FIG. 3). When the photographing mode 3 (entire average photometry mode) is selected in the photographing mode switching circuit 101, a coefficient 9 is assigned to α, a coefficient 10 is assigned to β, and a coefficient 1 is assigned to γ.
1 and the coefficient 12 are substituted for δ (step S204 in the flowchart of FIG. 3). Α, β,
γ and δ are coefficients used when calculating a photometric value described later, and as shown in FIG. 7, the coefficients are different depending on the photographing mode.

In the photographing mode 1, α = 10/10
0, β = 20/100, γ = 35/100, δ = 35 /
100 means that the gate frame for obtaining the photometric value shown in the supplementary diagram of FIG. 4 is used.

In the photographing mode 2, α = 0/100,
β = 0/100, γ = 0/100, δ = 100/10
The reason for setting to 0 is that after all, the area D is measured for light and the areas A, B, and C are not used for light measurement. That is, the gate frame shown in the supplementary diagram of FIG. 5 is used.

In the photographing mode 3, α = 50/10
0, β = 50/100, γ = 0/100, δ = 0/10
The reason for setting to 0 is that after all, photometry is performed on the area B and the area C, and the area A and the area D are not used for photometry. That is, the gate frame shown in the supplementary diagram of FIG. 6 is used.

The AE control signal calculation circuits 1 and 102 perform the above-described step S2 on the Ys1, Ys2, Ys3, and Ys4 generated in step S501, step S502, step S503, and step S504.
The photometric value is calculated by multiplying by a coefficient (α: β: γ: δ) for calculating the photometric value selected according to the shooting mode selected in 01, and further adding the respective values. In the present embodiment, the addition ratio of Ys1, Ys2, Ys3, and Ys4 is α: β: γ: δ, and the photometric value is Ys = Ys1 × α + Ys2 × β + Ys3 × γ + Ys4 ×
δ (Step S20 in the flowchart of FIG. 3).
5).

The exposure control is performed so that the level of the photometric value falls within a predetermined range.
By controlling the iris 401 and the AGC circuit 403.

As described above, according to the imaging apparatus according to the embodiment of the present invention, the photographing mode instructed from the outside is the center-weighted average photometry mode effective for photographing a normal subject, or the spotlight is used. A photographing mode switching circuit 101 for discriminating between a peak metering mode effective for photographing an illuminated object and a full-area average metering mode effective for horizontal panning, a luminance signal detection circuit 405, and a luminance signal peak value detection circuit A photometric value is generated by multiplying the photometric value calculated in 406 by a coefficient corresponding to the shooting mode determined and selected by the shooting mode switching circuit 101, and the level of the generated photometric value falls within a predetermined range. As described above, since the iris 401 and the AE control signal operation circuits 1 and 102 for controlling the AGC circuit 403 are provided, the following operations and effects are achieved.

In the above configuration, the shooting mode switching circuit 101 determines that the selected shooting mode is the shooting mode 1
It is determined whether the mode is (center-weighted average metering mode), shooting mode 2 (peak metering mode), or shooting mode 3 (overall average metering mode). Shooting mode 1 (center-weighted average metering mode) or shooting mode 2 (peak metering mode) selected and determined
Alternatively, according to shooting mode 3 (entire average photometry mode),
A predetermined coefficient is substituted for α, β, γ, and δ.

The AE control signal calculation circuits 1 and 102 use the generated photometric values Ys1, Ys2, Ys3, and Ys4 as coefficients (α: β) for calculating the photometric value selected according to the selected photographing mode. : Γ: δ) and further add each to calculate a photometric value, so that the level of the calculated photometric value falls within a predetermined range.
Exposure control is performed by controlling the circuit 403.

Therefore, in the embodiment of the present invention,
If a photometric value is generated by multiplying a plurality of photometric values by a predetermined coefficient and further adding each of them, it is possible to easily realize a plurality of photometric means by changing the coefficient. Becomes In other words, when the photographer intentionally switches the shooting mode according to the shooting scene, the center-weighted average metering, peak metering, and overall surface metering can be freely performed by changing only the above coefficients without greatly increasing the number of parts. This makes it possible to perform optimal exposure control.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (or CPU or MPU) of the system or the apparatus executes the program code stored in the storage medium. Needless to say, this can also be achieved by executing the reading.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS or the like running on the computer is actually executed based on the instructions of the program code. It goes without saying that a part or all of the above-described processing is performed, and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0058]

As described above, according to the imaging apparatus of the first to fifth aspects, the photometric value is generated by multiplying a plurality of photometric values by a predetermined coefficient, and further adding each of them. By doing so, it is possible to easily realize a plurality of photometric means by changing the coefficient. In other words, when the photographer intentionally switches the shooting mode according to the shooting scene, the center-weighted average metering, peak metering, and overall surface metering can be freely performed by changing only the above coefficients without greatly increasing the number of parts. This makes it possible to perform optimal exposure control.

According to the exposure control method of the present invention, by applying the exposure control method to the image pickup apparatus, center-weighted average photometry, peak photometry and full-area average photometry can be freely performed in the same manner as described above. There is an effect that selection can be realized and optimal exposure control can be performed.

According to the storage medium of the present invention, the exposure control method is read from the storage medium and executed by the image pickup apparatus, so that the center-weighted average photometry, the peak photometry, and the overall average photometry are performed in the same manner as described above. An effect is achieved in that selection can be freely performed and optimal exposure control can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a circuit configuration of an imaging device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating processing performed by an AE control signal operation circuit of the imaging apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating processing performed by an AE control signal operation circuit of the imaging apparatus according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating an imaging screen of the imaging device according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an imaging screen of the imaging device according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an imaging screen of the imaging device according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between an imaging mode and a coefficient in the imaging device according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a configuration example of storage contents of a storage medium storing a program and related data of the present invention.

FIG. 9 is an explanatory diagram showing a conceptual example in which a program and related data of the present invention are supplied from a storage medium to an apparatus.

FIG. 10 is a block diagram illustrating a circuit configuration of an imaging device according to a conventional example.

FIG. 11 is a flowchart illustrating processing performed by an AE control signal operation circuit of an imaging apparatus according to a conventional example.

FIG. 12 is an explanatory diagram showing an imaging screen of an imaging device according to a conventional example.

[Explanation of symbols]

 Reference Signs List 101 shooting mode switching circuit 102 AE control signal calculation circuit 1 401 iris 402 image sensor 403 AGC circuit 404 camera signal processing circuit 405 luminance signal detection circuit 405 luminance signal peak value detection circuit

Claims (11)

[Claims] A function of controlling the amount of transmitted light of an imaging optical system;
An imaging apparatus having a function of photoelectrically converting transmitted light and a function of calculating a photometric value of a predetermined area on an imaging screen, wherein a shooting mode switching unit that allows a photographer to intentionally switch a shooting mode, Photometric value generating means for generating a photometric value by adding a value obtained by multiplying a photometric value of a plurality of predetermined areas on the image capturing screen by a coefficient corresponding to a photographing mode selected by the photographing mode switching means; Control means for controlling the control system of the amount of transmitted light according to the photometric value generated by the means. 2. An iris adjusting means for controlling the amount of transmitted light of the imaging optical system, a photoelectric conversion means for accumulating the transmitted light and performing photoelectric conversion, and a video luminance signal for dividing the imaging screen into a plurality of parts. A first average light amount calculating means for calculating an average light amount by integrating a video luminance signal corresponding to a designated area on the imaging screen, and dividing the imaging screen into a plurality of image luminance signals. And a second average light amount calculating means for calculating an average light amount by integrating a video luminance signal corresponding to an area having the highest luminance on the imaging screen. An imaging device according to any one of the preceding claims. 3. The photographing mode switching means according to claim 1, wherein the photographing mode specified from the outside is a center-weighted average metering mode effective for photographing a normal subject or a peak metering effective for photographing a subject irradiated with spotlight. Mode, or the entire surface average photometry mode effective for shooting panned in the horizontal direction, and the photometric value generation means is calculated by the first average light quantity calculation means and the second average light quantity calculation means, respectively. The imaging apparatus according to claim 1, wherein a photometric value is generated by adding a value obtained by multiplying the photometric value by the coefficient according to the photographing mode selected and determined by the photographing mode switching unit. 4. The imaging apparatus according to claim 1, wherein the coefficient is set in advance to a value corresponding to the center-weighted average photometry mode, the peak photometry mode, and the overall average photometry mode. . 5. The imaging device according to claim 1, wherein the imaging device is applicable to a camera-integrated VTR or the like. 6. A function of controlling the amount of transmitted light of an imaging optical system,
An exposure control method applied to an imaging apparatus having a function of performing photoelectric conversion of transmitted light and a function of calculating a photometric value of a predetermined area on an imaging screen, and enables a photographer to intentionally switch a shooting mode. Photometric value generation for generating a photometric value by adding a value obtained by multiplying a photometric value of a plurality of predetermined areas on the image capturing screen by a coefficient corresponding to the photometric mode selected in the above-mentioned phototaking mode switching step. And a control step of controlling the control system of the amount of transmitted light according to the photometric value generated in the photometric value generating step. 7. An iris adjusting step of controlling the amount of transmitted light of the imaging optical system, a photoelectric conversion step of accumulating the transmitted light and performing photoelectric conversion, and a video luminance signal obtained by dividing the imaging screen into a plurality of parts. A first average light amount calculating step of calculating an average light amount by integrating a video luminance signal corresponding to a designated area on the imaging screen with a gate;
A second average light amount calculation that divides the imaging screen into a plurality of parts, gates a video luminance signal, and integrates a video luminance signal corresponding to an area having the highest luminance on the imaging screen to calculate an average light amount. 7. The exposure control method according to claim 6, further comprising the steps of: 8. In the photographing mode switching step,
The shooting mode specified from the outside is the center-weighted average metering mode that is effective for shooting ordinary subjects, the peak metering mode that is effective for shooting spot-irradiated objects, or the shooting mode that pans horizontally. In the photometric value generation step, the photometric value calculated in the first average light quantity calculation step and the second average light quantity calculation step are determined and selected in the shooting mode switching step. 8. The exposure control method according to claim 6, wherein a value obtained by multiplying the coefficient according to the selected shooting mode is added to generate a photometric value. 9. The exposure control according to claim 6, wherein the coefficient is set in advance to a value corresponding to the center-weighted average metering mode, the peak metering mode, and the overall average metering mode. Method. 10. The exposure control method according to claim 6, wherein the method is applicable to a camera-integrated VTR or the like. 11. An exposure control method applied to an imaging apparatus having a function of controlling the amount of transmitted light of an imaging optical system, a function of photoelectrically converting transmitted light, and a function of calculating a photometric value of a predetermined area on an imaging screen. A storage medium readable by a computer storing a program to be executed, wherein the exposure control method includes: a photographing mode switching step in which a photographer can intentionally switch a photographing mode; A photometric value generating step of generating a photometric value by adding a value obtained by multiplying a photometric value of a predetermined area by a coefficient corresponding to the image capturing mode selected in the image capturing mode switching step, and a photometric value generated in the photometric value generating step A control step of controlling the control system of the amount of transmitted light according to the following.