JPH02190832A - Photometric device for camera provided with automatic focusing function - Google Patents

Abstract

PURPOSE:To always obtain appropriate exposure in accordance with composition by automatically performing multiphotometry in which the main object is always weighted by means of obtaining the position of a main object on a photographic image plane after a camera or the main object moves even if the camera or the main object moves at the time of photographing. CONSTITUTION:At the time of photographing, the camera is set at a 1st position where the main object 20 is positioned in the center of the photographic image plane 10 to perform initial multiphotometry where AF and the main object 20 are weighted. Thereafter, when the camera moves, for example, the moving position of the main object 20 on the photographic image plane 10 is obtained. Then, the multiphotometry where the main object 20 is weighted is performed again at a 2nd position newly obtained. Thus, photographing is performed under the optimum exposing condition even after moving the camera.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an automatic camera that can automatically measure light at multiple locations with the weight of metering always placed on the main subject even if the main subject moves in the shooting screen. The present invention relates to a photometry device for a camera with a focusing function.

[Conventional technology]

In conventional cameras, photometry is performed on the main subject located in the distance measurement area in the center of the shooting screen. In recent cameras, a system has been proposed that corrects backlight for the main subject located in the center of the screen before shooting by providing multiple photometry areas within the shooting screen, that is, by performing so-called multi-metering. There is. In such a multi-metering method, when the first release switch performs AF (autofocus) on the main subject located within one distance measurement area at the center of the screen, multi-metering is performed at the same time. Generally, information is fixed.

On the other hand, most cameras now have a focus lock function, so the photographer can

Cameras are often used in a complicated manner, with AF and multi-metering information fixed, while the main subject's position on the screen is freely moved from the center position (so-called changing the composition). When shooting in this way, the final brightness distribution on the screen at the time of shooting is different from the brightness distribution at the time when the multi-photometry axis is fixed, so if you shoot with the same brightness distribution, it will be undesirable. Proper exposure.

Conventionally, after fixing the AF and photometry information, the AE
(Automatic exposure) First method of re-metering using a locking device
0), and a second method (Japanese Patent Laid-Open No. 62-203140) that performs multi-photometering after fixing the AF and weights the luminance information of the area including the distance measurement area to determine the final photometry conditions.
In addition, multiple distance measurement areas and equivalent photometry areas are provided in the shooting screen, distance measurement and photometry are performed respectively, and the distance measurement area where the main subject is located is determined from among these areas, and the distance measurement area where the main subject is located is determined from among these areas. The third step determines whether the main subject is backlit from the photometry results of the area containing the main subject and other areas.
(Japanese Unexamined Patent Publication No. 62-255925) has been proposed.

[Problem to be solved by the invention]

Among the conventional examples, those based on the first and second methods often require a special manual operation by the photographer when determining the final photometric information, and in such cases, the photographer There are cases where the operator forgets or does not know about the manual operation, and there is a risk that inappropriate exposure may be performed.

Furthermore, none of the first to fourth methods have a means for learning the changed position of the main subject on the new screen.

There is a serious problem in that it is not possible to perform proper multi-photometry that places more weight on the main subject.

Furthermore, the method according to the fourth method requires an AP device for each of a plurality of distance measurement areas, which increases the cost and has the disadvantage that it cannot be used in low-priced cameras.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable the photographer to perform a distance measurement operation on the main subject located in the distance measurement area on the shooting screen, and also perform multi-metering. Even if you change the shooting screen to change the post-composition and take a picture, multi-metering can be performed automatically with the metering weight always placed on the main subject, and this can be achieved at a low cost. An object of the present invention is to provide a photometry device for a camera with an automatic focus adjustment function.

[Means to solve the problem]

The photometry device for a camera with an automatic focus adjustment function according to the present invention includes:
It has an automatic focus adjustment means that measures the distance to the main subject in the distance measurement area on the shooting screen and automatically brings the shooting lens to the focusing position, and has multiple photometry areas on the shooting screen, each photometry area A photometer that measures the light of a subject located within the photometer and outputs a photometering signal according to the subject light for each photometering area, and a motion detector that detects a change in the relative position between the camera and the main subject after the photometering. means, and outputs a release signal for causing the automatic focus adjustment means to perform distance measurement and the photometry means to perform initial photometry in response to a release operation, and for fixing information on the resulting distance measurement and initial photometry. and a first release switch means for receiving the release signal outputted from the first release switch means and causing the automatic focus adjustment means to perform distance measurement and focusing operations on a main subject existing in the distance measurement area. The photometry means performs a photometry operation that places a photometry weight on the photometry area where the main subject is located, and when a change in the relative position is detected by the movement detection means thereafter, the output of the movement detection means The main subject's position on the photographing screen is determined based on the position of the main subject, and the control means moves the weight of photometry to the photometry area corresponding to this position and causes the photometry means to perform photometry again. This is what I did.

[For production]

With the above configuration, when shooting, the camera is set at the first position with the main subject at the center of the shooting screen, AF and initial multi metering is performed with weight placed on the main subject, and then, for example, when the camera moves, At this time, the moving position of the main subject on the photographic screen is determined, and multi-photometering is performed again with weight placed on the main subject at this new second position. Therefore, even after moving the camera, shooting will be performed under optimal exposure conditions.

〔Example〕

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a block circuit diagram showing a circuit configuration of an embodiment of a photometric device for a camera with an automatic focus adjustment function according to the present invention, and FIG. 2 shows a photographing screen of a camera equipped with a photometric device according to the present invention. It is an explanatory view shown typically.

In FIG. 1, 1 is a control circuit having logical and arithmetic processing capabilities composed of a microcomputer, etc.
A first release switch 2 and a second release switch 3 are connected to the control circuit 1, which are opened and closed by a shirt release operation.

4 is an AF section (automatic focus adjustment section) that measures the distance to the subject and automatically drives the photographing lens to the in-focus position;
Reference numeral 1 denotes a multi-photometering section that performs photometry for each of a plurality of photometry regions formed by dividing a light-receiving region corresponding to a photographic screen into a plurality of regions, 6 a motion detection section, and 7 a shutter section. Note that the illustration of the power supply portion in FIG. 1 is omitted.

In the photographing screen 10 shown in FIG. 2, numeral 11 indicates a frame of a distance measurement area, and five areas 12 to 16 indicate photometry areas for performing multi-photometry.

The AF section 4 in FIG. 1 performs AF (distance measurement/focusing operation) on a subject existing within the distance measurement area located at the center of the screen divided by a frame 11 on the photographing screen 10 in FIG. conduct.

The multi-photometry section 5 divides the photographic screen into five areas 12 to 16 and performs photometry for each area.

The motion detection unit 6 is a part that has a function of detecting camera movement (for example, a change in relative position between the camera and the main subject) caused by hand-held movements such as vanning by the photographer, and is a part that has a control circuit. 1 outputs information used to calculate the direction and amount of change regarding camera movement. An example of a configuration for motion detection by the motion detection unit 6 is, for example, a built-in acceleration sensor having sensitive axes in two directions, up and down and left and right, and AF with the main subject as the target.
and from the first position when photometry was performed.

The output signals of the two acceleration sensors that are output when the camera is moved to a second position other than that in order to change the ellipse are integrated while the camera moves from the first camera position to the second camera position, and each Calculates the amount of displacement and direction of the camera based on the integral value of , and determines the direction and amount of change in the position of the main subject on the shooting screen using information on the amount of displacement of the camera, the focal length of the camera's photographing lens, and AF information. It is configured as follows. The calculation operation in this motion detection is performed by the calculation function of the control circuit 1.

In addition, as another configuration example of motion detection by the motion detection unit 6, the camera moves from the first position to the second position using an image sensor device consisting of a plurality of photoelectric conversion elements, an image memory, etc. It is also possible to create image information for each movement and to determine the displacement of the main subject on the photographic screen based on changes in the image. In the case of this latter configuration example, the motion detection sensor used in the motion detection section 6 can also be used as an AF sensor.

The first release switch 2 is turned on when the release button is pressed down to the first stage, and the release signal is input to the control circuit 1 by the on operation, and the AF unit 4 performs AF and multi-metering according to commands from the control circuit 1. Multi-metering by section 5 is performed simultaneously, and the light metering at this time is performed in frame 1.
The weight of photometry is placed on an area 12 that is substantially common to the distance measurement area surrounded by 1. The second release switch 3 is turned on by the next pressing operation (full-pressing operation) of the release button, and by the turning-on operation, the shutter section 7 is driven according to the set exposure condition and photographing is performed.

The control circuit 1 is for controlling a series of camera photographing operations according to the present invention, including all the functions described above, and controls the weighting of photometry based on the information about the movement of the camera given from the movement detection section 6. It has a function of outputting a command signal for changing to any one of areas 12 to 16 in FIG. 2 and performing multi-photometry again.

Next, the photometry operation of the camera will be explained based on FIG. 1 and FIGS. 3 to 6.

In the flowchart of FIG. 6, the photographer first positions the camera (first position ) (step 30), and in this set state, press the release button (not shown) halfway to turn on the first release switch 2 (step 31).
).

The control circuit 1 that receives the release signal generated by this operation issues commands to each of the AF section 4 and the multi-photometering section 5, thereby causing the AF section 4 and the multi-photometering section 5 to
AF and multi-photometry with weight placed on area 12 are performed by each of (step 32). Information on AF at the first position of the camera and multi-photometry with weight placed on area 12 is sent to the control circuit 1 and stored in a memory (not shown). That is, the AF for the first position
and multi-photometry information is locked (stored).

Next, the photographer freely considers the composition of the photographic screen 1o while keeping the AF/multi-metering information locked, that is, keeping the first release switch 2 turned on.

Here, it is assumed that the camera is moved so that the photographing screen 10 moves in the direction indicated by the arrow f, as shown in FIGS. 3 and 4. Then, the position of the main subject 20 on the photographing screen 10 is changed to the photographing screen 1o as shown in FIG.
to the position of area 16. In this new screen, for example, a bright area 21 such as the sky comes into view, so it is not possible to take a photograph with proper exposure using the photometric information based on the screen in FIG. 3.

Therefore, in the next step 33, the control circuit 1 determines whether or not there has been movement of the camera based on the output signal of the motion detection section 6, and when it is determined that there has been movement of a predetermined amount or more, the process proceeds to step 34.

In step 34, the amount of displacement and direction of the camera are calculated from the direction and amount of displacement indicated by the arrow f, and further, based on the information on the amount of displacement of the camera, the focal length and AF information of the photographing lens of the camera, the photographing screen 10 is The position of the main subject 20 at is calculated. As a result, it is found that the main subject 20 has moved from the area 12 to the area 16 on the photographic screen 10. Therefore, in this second position, the photometry weight is set to region 1.
2 to area 16 (step 35), photometry area 1
The multi-photometering unit 5 performs the multi-photometering again with the weight of photometry placed on the photometer 6 (step 36).In the first multi-photometering, the bright sky area that did not exist in the photographic screen 10 is changed to the area 13 by moving the camera. Even if the subject is in a backlit state, the fact that the subject is in a backlit state is inputted as photometry information by re-implementing this multi-photometry. Thereafter, if it is determined in step 37 that the second release switch 3 has been turned on by fully pressing the release button, a photographing command is given from the control circuit 1 to the shutter unit 7 and photographing is performed (step 38
) 6 When the second release switch 3 is in the off state, steps 33, 34, 35 and 36 are repeated, camera movement detection, weight area change, and multi-photometry re-implementation are repeated, and the final The photometric information at the position where the camera stops moving is required.

Note that the present invention is not limited to the embodiments described above, and various modifications and changes can be made without departing from the gist thereof.

For example, in the above embodiment, the movement detection unit 6 mainly detects the movement of the camera itself, but when the main subject 20 moves within a certain range and changes its position within the shooting screen 10. The motion detection section 6 can also be configured to output data necessary for the motion detection section 6 to calculate the position of the main subject on the screen.

[Effects of the Invention] According to the present invention, which is clear from the above description, even if the camera or the main subject moves during shooting, the position of the main subject on the shooting screen after the movement is determined, and the main subject is always Since the configuration is configured to automatically perform multi-metering with weighted photometry, even if you freely change the composition after focus lock on a camera equipped with automatic focus adjustment and focus lock functions, multi-metering will not be performed according to the composition. This is done automatically, allowing you to always take photos with the correct exposure.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing the circuit configuration of an embodiment of a photometry device for a camera with an automatic focus adjustment function according to the present invention, and FIG. FIG. 3 to FIG. 5 are explanatory diagrams showing changes in the state of each shooting screen when the camera moves, and FIG. 6 is a flowchart showing the operation order of the same embodiment. It is. 1...Control circuit, 2...Second release switch, 3...Second release switch, 4...AF section, 5...Multi metering 6...Motion detection part, 7...Shutter part. 1o... Shooting screen, 11... Range measurement area frame, 12-16... Photometry area, 20... Main subject. Patent applicant Rico Co., Ltd. −

Claims (1)

[Claims] It has an automatic focus adjustment means that measures the distance to the main subject in the distance measurement area on the shooting screen and automatically brings the shooting lens to the focusing position, and has multiple photometry areas on the shooting screen, each photometry area A photometer that measures the light of a subject located within the photometer and outputs a photometering signal according to the subject light for each photometering area, and a motion detector that detects a change in the relative position between the camera and the main subject after the photometering. means, and outputs a release signal for causing the automatic focus adjustment means to perform distance measurement and the photometry means to perform initial photometry in response to a release operation, and for fixing information on the resulting distance measurement and initial photometry. and a first release switch means for receiving the release signal outputted from the first release switch means and causing the automatic focus adjustment means to perform distance measurement and focusing operations on a main subject existing in the distance measurement area. The photometry means performs a photometry operation that places a photometry weight on the photometry area where the main subject is located, and when a change in the relative position is detected by the movement detection means thereafter, the output of the movement detection means The main subject's position on the photographing screen is determined based on the position of the main subject, and the control means moves the weight of photometry to the photometry area corresponding to this position and causes the photometry means to perform photometry again. A camera photometer with automatic focus adjustment function.