JP2003153045A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of easily confirming whether a subject desired by a photographer is correctly focused or not. SOLUTION: In this camera, focusing is performed on any of subjects existing in a plurality of points 10L, 10C or 10R in the scope of a finder by focus judging sections 19, 20. A photographing screen taken into a photographing element 16 is displayed on an LCD screen 25 as a main image via an LCD driver 24. Of the plurality of points 10L, 10C or 10R, the image near an area used for focusing is displayed on the screen 25 as a sub-image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a camera with a digital image monitor in which a captured image can be confirmed on a screen such as a liquid crystal (CCD).

[0002]

2. Description of the Related Art In recent years, digital cameras have become widespread, but especially regarding focusing, it is difficult to obtain a photograph of a focus as intended by the user, and further improvement is required.

As a technique for confirming the result of such autofocus (AF), there is known a technique for displaying the AF result as described in Japanese Patent Laid-Open No. 10-48733. There is also known a technique of superimposing the focusing portion on the finder screen.

Conventionally, as shown in FIG. 8A, in a scene in which subjects having various spatial frequencies and distances are mixed in the screen 1, a miscellaneous subject different from the main subject may be in focus. It was The in-focus state of the subject cannot be determined by a small monitor built in the camera, and it is often understood only by confirming it on a printout or a large monitor after shooting.

That is, as shown in FIG.
In the scene 2, the miscellaneous subject 3 around the scene 2 is clearly in focus, but the important person 4 is out of focus.

[0006]

However, the above-mentioned improvements are not sufficient for the photographer to confirm the focus condition. Therefore, there is a demand for a technique for more directly displaying where the focus is on the screen.

Further, when the superimposed display is made on the screen, the screen becomes difficult to see, and a frame or the like that is not actually photographed is displayed on the screen, which may cause confusion for the user. Was.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a camera capable of easily confirming whether or not a subject assumed by a photographer is correctly focused.

[0009]

SUMMARY OF THE INVENTION That is, the present invention provides a focusing means for focusing on any of the subjects present at a plurality of points on the screen, a first display means for displaying a photographing screen, and a plurality of the above-mentioned plurality of means. The second display means for displaying an image in the vicinity of the area used for the focusing among the above points.

The present invention further comprises a distance measuring means for measuring a plurality of points in the photographing screen, an image pickup means for photographing the image of the photographing screen through a photographing lens and digitally displaying the image. Display means for displaying an image photographed by the image pickup means, and focusing means for controlling a part of the photographing lens based on the output of the distance measuring means and the output of the image pickup means to focus on a subject. In the camera provided, a control means is provided on the display means for displaying a digital image corresponding to a point selected for focusing by the output of the distance measuring means.

In the camera of the present invention, any one of the subjects existing at a plurality of points on the screen is focused by the focusing means. Then, the photographing screen is displayed on the first display means, and the image of the vicinity of the area used for focusing among the plurality of points is displayed on the second display means.

In the camera of the present invention, the distance measuring means measures a plurality of points on the photographing screen,
The image of the photographing screen is photographed by the image pickup means through the photographing lens and digitally displayed, and the photographed image is displayed by the display means. Further, based on the output of the distance measuring unit and the output of the image pickup unit, a part of the photographing lens is controlled by the focusing unit to focus on the subject. Then, on the display means, a digital image corresponding to the point selected for focusing by the output of the distance measuring means is displayed by the control means.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the internal electrical configuration of a camera according to the first embodiment of the present invention.

In FIG. 1, reference numeral 10 indicates a scene or screen range photographed by this camera. As in this scene 10, the person 11a as the main subject is small, and the one that occupies most of the screen is a distant landscape, and the trees 11b and mountains are mixed and the spatial frequency is low or high. If the objects are mixed, the camera is used as the main subject 11a.
I often accidentally focused on something other than this.

The photographing light flux from the subject is taken by the photographing lens 15
Is guided to the image sensor 16 that forms an image signal. Then, the image data is image-processed by the image pickup device 16, the image information is supplied to the image processing circuit 17 and the memory 18, and the CPU 20 through the focus determination unit 19.
Is supplied to.

The CPU 20 is an arithmetic control unit composed of a one-chip microcomputer or the like. Then, in the CPU 20, a lens driver (LD) 23 for driving the photographing lens 15 and an LCD screen 2 which is a means for displaying a photographed image via an LCD driver 24.
5 is connected, and a strobe light emitting section 26 as auxiliary light, a release switch 27 and an image display mode changeover switch 28 are also connected.

In such a structure, the taking lens 15
An image signal is formed by the image sensor 16 via the. Then, the image data formed by this image sensor is stored in the CPU 20.
In response to a command from the image processing circuit, the image processing circuit performs image processing, and the image is recorded in the memory 18 or displayed on the LCD screen 25. Further, by operating the release switch 27 or the image display mode changeover switch 28, the sequence of the entire camera is controlled by a built-in program, and the image sensor 16
Focusing control and the like are performed from the output of.

That is, a predetermined spatial frequency component is taken out, and its contrast is judged by the focus judging section 19. Then, the output of the focus determination unit 19 is used, and the CPU 20 controls the taking lens 15 via the lens driver 23, so that focusing is performed.

Also, at the time of shooting, the LCD screen 2 for display
In order to display an image on the LCD 5, the LCD driver 24 has a CPU
Controlled by 20. In particular, when operating the in-focus position confirmation function, which is a feature of the present invention, the CPU 20 selects only a specific portion of the image sensor 16 via the image processing circuit 17 and controls the LCD driver 24,
The selected part is cut out and displayed.

When the exposure is insufficient, the CPU 20 controls so that the strobe light emitting section 26 emits light to supplement the light.

As shown in FIG. 2, the image pickup device 16 has three focus detection areas 16a, 16b and 16c. Although the focus detection areas are described as three here, the number of detection areas may be five or seven including one point in the center. And
For example, the three focus detection areas 16a and 16 described above
b and 16c correspond to the three points 10L, 10C and 10R of the scene 10 shown in FIG.

Next, with reference to FIG. 3, a state in which the user handles the camera 30 having such a configuration will be described.

As shown in FIG. 3A, the camera 30
On the back surface (upper side in the figure) of the
A D screen 25 is provided. A release switch 27, an image display mode changeover switch 28, etc. are provided on the upper surface of the camera 30. In response to the operation of these various switches, the CPU not shown in FIG.
It is controlled to switch the display of D30.

Therefore, the user 31 has the LCD screen 2
While looking at 5, it is possible to determine whether the focus and composition are correct. As a result, in a scene such as that shown in FIG. 1, focus detection can be performed even if the subject (person 11a) does not exist in the center of the screen range 10.

However, simply by confirming on the LCD that the subject is in the composition, the background or the like, which was not originally intended to be focused, comes into focus.
There was a phenomenon that the main subject of interest was out of focus. In such a case, the actually photographed image becomes difficult to see as shown in FIG.

Therefore, in the camera of the present invention, as shown in FIG.
The screen is divided into a main screen 25a and a sub screen 25b. For example, like the three points 10L, 10C, and 10R in the screen shown in FIG. 1, the focus can be checked with respect to the three points in the screen, and the subject existing at any one of the points can be focused. Specifications are assumed.

Here, the image of the selected point is displayed on the sub screen 25b. On the other hand, the main screen 25a
Displays all of the captured images. As shown in FIG. 3A, the user 31 can confirm the focus point automatically selected by the camera on the sub screen in the LCD screen 25.

Further, by operating the image display mode changeover switch 28, the sub screen may be switched to the main screen for a large display, or the full screen may be displayed on the sub screen 25b. Furthermore, as shown in FIG. 3C, a second sub-screen 25c is provided, and the second sub-screen 25c is provided.
The next candidate for focusing may be displayed on c. However, in this case, it is effective to use it for the determination after focusing.

In this way, the main screen 25a does not need to be displayed with an extra frame or the like indicating the focus point, has a neat screen, and the photographing screen can be correctly monitored.

Next, referring to the flowchart of FIG.
The control operation of the camera in the present embodiment will be described.

First, in step S1, the portion to be imaged is displayed on the main screen 25a at the timing of operation of the release switch 27. At this time, the photographic lens 15 is in a position where any object can be seen on the monitor with a proper focus at the pan focus position.

Next, in step S2, the taking lens 1
5 is initialized at a position of infinity (∞), for example. Then, in steps S3 to S5, the taking lens 15 is moved while the contrast of the predetermined frequency components in the three areas 16a, 16b, 16c shown in FIG. 2 is determined.

That is, in step S6, the position of the taking lens 15 is determined. As a result, shooting lens 1
If 5 has not reached the end position, the process moves to step S7 and the position is moved. Then, the process proceeds to step S3.

On the other hand, in step S6, the taking lens 15
Is reached to the end position, in step S8, it is detected in each area 16a to 16c which lens position (focus position) should be used for the best focus. However, since all the areas have good focusing at different lens positions, in step S9, the area showing good focusing at the shortest distance is selected from these. This is the first focusing candidate.

Thus, in the subsequent step S10, as shown in FIG.
From the points 10L, 10C, 10R shown in
Selected points (area 16a, 1 shown in FIG. 2)
The image near (corresponding to either area 6b or 16c)
Displayed on the sub screen. After this step,
The image of the area to be focused is displayed on the sub-screen 25b of (b).

By the way, in steps S3 to S7 described above, since the relationship between the contrast of each point and the lens position is obtained when the lens is scanned first, the contrast data of the selected point is most determined in step S11. The lens position that becomes higher is brought into focus, and imaging is performed in subsequent step S12. At this time, the main image 25a and the sub-screen 25b are again displayed with the entire image after focus and the selected portion image, respectively.

Next, in step S13, the image is compressed and stored in the memory 18. And step S1
At 4, it is determined whether the image display mode changeover switch 28 has been operated. As a result, if the image display mode changeover switch 28 is operated, the process proceeds to step S15, and the selected image is displayed on the main screen 25a.

That is, what has been displayed on the sub screen 25b until now is displayed on the main screen 25a. This makes it easier for the user to check the focus. At this time, the whole image is reduced and displayed on the sub-screen 25b, or the display of other points not selected is displayed on the second sub-screen 2b.
You may make it displayed on 5c. This allows the user to check whether the main subject is in focus or what the other points are.

On the other hand, if the image display mode changeover switch 28 is not operated in step S14, the process proceeds to step S16, and it is determined whether or not re-imaging has been performed. That is, the state of the release switch 27 is determined. Here, if the release switch 27 is pressed and re-imaging is performed, the process proceeds to step S17, and if re-imaging is not performed, this routine is exited.

In step S17, the image data used in the previous shooting is cleared, and in the following step S18, all the images are displayed on the main screen 25a. Then, in step S19, the next candidate point is brought into focus and the image is taken again. Then, the process proceeds to step S10.

As described above, according to the first embodiment, the user can easily take a picture while feeling the focus of the main subject that he or she is aiming for. In addition, there is no extra display other than the image on the main screen, and it is possible to determine whether or not the camera is focusing correctly by simply glancing at the sub screen.

As described above, according to the first embodiment,
It is possible to provide a camera capable of shooting while accurately determining the focus, composition, or facial expression of a subject.

In order to simplify the explanation, this flow chart is based on the idea that once the photograph has been taken and if the photograph has not been taken correctly, the photograph should be taken again. However, the specification is not limited to this, and the specification may be such that the release switch 27 is pressed halfway to confirm the monitor and fully pressed to end the shooting.

Next, a second embodiment of the present invention will be described.

In the second embodiment, not only the focusing using the image pickup device as in the above-described first embodiment but also the parallax of the image signal obtained by the sensor array through the two light receiving lenses is performed. This is a combined use of a so-called external light type triangulation method in which distance measurement is performed using the position difference x according to

FIG. 5 is a diagram showing an internal electrical configuration of a camera according to the second embodiment of the present invention.

In FIG. 5A, a pair of light receiving lenses 35a and 35 are provided at a position separated from the main subject 11 by a distance L.
b are spaced apart from each other by a distance B. The sensor arrays 36a and 36b are arranged at positions away from the light receiving lenses 35a and 35b by a distance f. Then, these sensor arrays 36a and 3a
The output of 6b is supplied to the CPU 20 via the A / D converter 37.

The configuration other than the above is the same as the configuration of FIG. 1 except that the release switch 27 is replaced with the first release switch 27a and the second release switch 27b, and the description thereof will be omitted.

The data of the sensor arrays 36a and 36b are digitized by the A / D converter 37. In the CPU 20, the position difference x described above is obtained by comparing these two digital image data, and L = B
The subject distance L is calculated from the relational expression of f / x. Here, as described above, B is the distance between the principal points of the light receiving lens, and f is the distance between the light receiving lens and the sensor array.

With respect to the distance obtained by such a distance measuring device, the CPU 20 focuses the photographing lens 15 via the lens driver 23. However, when photographing a dark scene, the brightness of the photographing lens 15 and the image pickup device are adjusted. Based on the brightness of 16, the light amount control of the strobe light emitting unit 26 is also performed. Further, the control and operation of the first release switch 27a, the second release switch 27b, the display of the LCD screen 25, etc. are based on the above-described first embodiment.

In the screen range 10, the range 40 monitored by the above-described sensor array for triangulation is shown in FIG.
Is shown in. Therefore, depending on which of the areas 41L, 41C, and 41R of this sensor array is used, the distance can be measured at three points on the screen. This can be done with 5 points or 7 points depending on how to divide the area to be used.

FIG. 6 is an external perspective view of the camera having such a configuration as seen from the front.

A photographic lens 15 is provided at a substantially central portion of the front surface of the camera 30, and light receiving lenses 35a and 35b are arranged above the photographic lens 15. Further, a strobe light emitting section 26 is provided in parallel with the light receiving lenses 35a and 35b.

A release switch 27 including a first release switch 27a and a second release switch 27b, and an image display mode changeover switch 28 are provided on the upper surface of the camera 30.

FIG. 7 is a flow chart for explaining the focus determination and photographing operations of the camera according to the second embodiment of the present invention.

In the second embodiment, the release switch has a two-stage configuration as described above, and the first release switch 27a is turned on for the first stage to perform display control, and the second release switch is used for the second stage. It is assumed that 27b is turned on and a picture is taken.

Further, since the signal of the image pickup device at the time of display is not particularly required to be recorded, it is treated as data in a so-called through mode without performing compression or the like. On the other hand, at the time of image pickup, compression or the like is necessary for recording, and the image processing circuit 17 processes the output of the image pickup device and records it in the memory 18.

In step S21, as described above, the distances of the three points (points 41L, 41C, 41R shown in FIG. 5B) on the screen are measured by the triangulation device, and the respective distance measurement results are obtained. Submitted as L _L , L _C , L _R.
Next, in step S22, the closest distance is selected from the distance measurement results obtained in step S21.
The selected one is the main subject distance, and the point at which this distance is output is the main subject point.

This is because, in general, the subject existing at the closest distance is often the main subject, and it is not always necessary to select by this short distance method. It is needless to say that more accurate selection can be performed by the image signal and the contour detection, but here, for the sake of simplicity of explanation, a short-distance selection method will be used.

In order to display the thus obtained selection section on the sub-screen 25b as shown in FIG. 3 (b), it is displayed in step S23 and in step S24. In step S24, the main image is displayed as a full screen.

Next, in step S25, the state of the image display mode changeover switch 28 is detected. Here, when the image display mode changeover switch 28 is operated,
Go to step S26, step S26 if not operated
Move to 28.

In step S26, the image of the selection portion displayed on the sub-screen 25b is focused and imaged. This makes it possible to check the focus accurately. Then, in step S27, the sub screen 2
The image of the selection section displayed on 5b is switched to the main screen 25a and enlarged-displayed as shown in FIG. 3 (c).

Then, in step S28, it is determined whether or not photographing is possible, that is, whether or not the release switch is depressed. Here, if shooting is possible, step S
Then, the process shifts to step 29, and more detailed focus control is performed with emphasis on the contrast of only the selection section. On the other hand, when shooting is not possible, this routine is exited.

In step S29, the contrast of the image of the selection portion is set, and in the following step S30, the taking lens 15 is driven. Further, in step S31, it is detected whether or not the contrast value obtained in steps S29 and S30 has a peak. Here, steps S29 to S31 are repeated until the peak value is detected.

When the peak value is detected, the process proceeds to step S32, and the photographing lens position is controlled to be set at that position. After that, when imaging is performed in step S33, this routine ends.

As described above, according to the second embodiment, the focusing point is selected at high speed based on the result of triangulation without lens scan, the selected position is imaged and displayed on the sub screen. As a result, high-speed focus determination becomes possible, and more rapid shooting becomes possible. The user can enjoy more advanced shooting by checking the composition of the entire screen on the main screen and watching the selection points on the sub screen. For this reason, it is easy to add a specification such as enlarging and displaying the sub screen.

According to the above embodiment of the present invention,
The following configuration can be obtained.

That is, (1) distance measuring means for measuring a plurality of points on the photographing screen, image pickup means for digitally displaying the image of the photographing screen via the photographing lens, and display means, In a camera having an output of the distance measuring means and a focusing means for controlling a part of the photographing lens based on the output of the image pickup means to focus on a subject, A camera comprising a control means for displaying a digital image corresponding to a point selected for focusing by the output of the distance measuring means.

(2) The camera according to (1), characterized in that the focusing means controls the taking lens to a position where the output of the imaging means is most appropriate by the photographing operation after the display. .

[0071]

As described above, according to the present invention, it is possible to provide a camera capable of accurately focusing on a main subject even on a screen in which subjects at various distances are mixed. In addition, it is possible to provide a camera that allows a user to easily recognize an object to be focused and accurately check a subject on a neat screen.

[Brief description of drawings]

FIG. 1 is a block diagram showing an internal electrical configuration of a camera according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a focus detection area of the image sensor 16 of FIG.

FIG. 3 is a diagram illustrating a state in which a user is handling the camera having the configuration of FIG. 1.

FIG. 4 is a flowchart illustrating a control operation of the camera according to the first embodiment.

FIG. 5 is a diagram showing an internal electrical configuration of a camera according to a second embodiment of the present invention.

6 is an external perspective view of the camera of FIG. 5 as seen from the front.

FIG. 7 is a flowchart illustrating operations of focus determination and shooting by the camera according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating a conventional autofocus technique for a camera.

[Explanation of symbols]

10 scenes (screen range), 10L, 10C, 10R points, 11a person (main subject), 15 shooting lens, 16 image sensor, 16a, 16b, 16c focus detection area, 17 image processing circuit, 18 memory, 19 Focus determination section, 20 CPU, 23 Lens driver (LD), 24 LCD driver, 25 LCD screen, 25a Main screen, 25b, 25c sub screen, 26 Strobe emission part, 27 Release switch, 28 Image display mode switch, 30 cameras, 31 users.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // H04N 101: 00 G03B 3/00 AF term (reference) 2H011 AA03 BA31 DA05 2H051 AA00 BA47 DA07 GA03 GA10 GA17 2H102 AA41 5C022 AA13 AB15 AB22 AC03 AC31 AC54 AC69 AC74

Claims (4)

[Claims] 1. A focusing means for focusing on any one of subjects existing at a plurality of points on the screen, a first display means for displaying a photographing screen, and a focusing means for focusing on the subject among the plurality of points. A second display unit for displaying an image of the vicinity of the used area, and a camera. 2. A focus confirmation switch for confirming the focus adjustment, and an image displayed on the second display means on the first display means when the focus confirmation switch is operated. 2. The camera according to claim 1, further comprising display switching means. 3. A distance measuring means for measuring a plurality of points in a photographing screen, an image pickup means for photographing an image of the photographing screen through a photographing lens and digitally displaying the image, and the image pickup means. A camera including display means for displaying a photographed image, and focusing means for controlling a part of the photographing lens based on the output of the distance measuring means and the output of the image pickup means to focus on a subject In the camera, there is provided on the display means a control means for displaying a digital image corresponding to a point selected for focusing by the output of the distance measuring means. 4. The camera according to claim 4, wherein the control means drives and controls the photographing lens to a position where an output of the image pickup means is most appropriate by a photographing operation after the digital image is displayed.