JP2007174574A - Digital single lens reflex camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital single lens reflex camera which makes moving picture shooting enable, even if it is in the middle of still picture shooting. <P>SOLUTION: This digital single lens reflex camera is constituted of an optical finder which can observe the luminous flux which passed along an imaging lens 1, a picture capture portion 17 which is arranged in the optical finder and which can photograph moving pictures, and an imaging portion 18 which images a still picture from the luminous flux which passed along the imaging lens 1. When the imaging portion 18 performs still picture shooting under moving picture shooting by the picture capture portion 17, a still picture, obtained by the imaging portion 18, is made utilizable as a moving picture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a digital single lens reflex camera capable of shooting both a still image and a moving image.

As a digital single-lens reflex camera capable of shooting both a still image and a moving image, an image acquisition unit is provided on the optical path of an optical viewfinder and used for moving image shooting (see, for example, Patent Document 1).
US Pat. No. 4,704,022 (see Image Pickup Device 20)

  However, a digital single lens reflex camera raises a quick return mirror for guiding a subject image to an optical viewfinder when taking a still image. Therefore, when the digital single-lens reflex camera performs still image shooting, the light beam does not enter the image acquisition unit provided on the optical viewfinder side. Therefore, there is a problem that the image acquisition unit cannot perform moving image shooting while the digital single lens reflex camera is shooting a still image (while the quick return mirror is up).

  An object of the present invention is to provide a digital single-lens reflex camera that enables moving image shooting even during still image shooting.

  The digital single-lens reflex camera according to claim 1 includes an optical finder unit that can observe a light beam that has passed through an imaging lens, an image acquisition unit that can shoot a moving image disposed in the optical finder unit, and a light beam that has passed through the imaging lens. An image pickup means for picking up a still image, and a control means for using the still image obtained by the image pickup means as a moving image when the image pickup means performs still image shooting during moving image shooting of the image acquisition means.

The digital single-lens reflex camera according to claim 2 is characterized in that, in the digital single-lens reflex camera according to claim 1, the control means shoots a still image and a moving image under the same shooting conditions.
The digital single-lens reflex camera according to claim 3 is the digital single-lens reflex camera according to claim 2, wherein the photographing conditions are an aperture value and sensitivity.

The digital single-lens reflex camera according to claim 4 is the digital single-lens reflex camera according to claim 1 or 2, wherein the control means changes the sensitivity and changes the still image when the shooting conditions of the still image and the moving image are different. It is characterized by taking a picture.
The digital single-lens reflex camera according to claim 4 is the digital single-lens reflex camera according to any one of claims 1 to 4, wherein the control means includes a moving image immediately before the start of still image shooting and a Based on the moving image and the still image, a moving image that is insufficient over the still image shooting time is created and interpolated.

The digital single-lens reflex camera according to claim 6 is the digital single-lens reflex camera according to any one of claims 1 to 4, wherein the control means includes a plurality of images based on a plurality of captured still images. A moving image is created, and a shortage of moving images over the still image shooting time is interpolated using the plurality of created moving images.
The digital single-lens reflex camera according to claim 7 is the digital single-lens reflex camera according to claim 6, wherein the control unit is configured to select one based on at least two adjacent still images among a plurality of still images taken. A moving image is created, and a deficient moving image is interpolated using the created moving image according to a still image shooting time.

The digital single-lens reflex camera according to claim 8 is the digital single-lens reflex camera according to any one of claims 1 to 7, wherein the image acquisition unit also serves as an exposure control sensor. To do.
The digital single-lens reflex camera according to claim 9 is the digital single-lens reflex camera according to any one of claims 1 to 7, wherein the image acquisition means stores stored data when the quick return mirror is up. Reading is performed, and the imaging means reads stored data when the quick return mirror is down.

  According to the present invention, it is possible to provide a digital single-lens reflex camera capable of shooting a moving image even while shooting a still image.

Hereinafter, embodiments shown in the accompanying drawings will be described.
FIG. 1 is a block diagram showing an embodiment of the present invention.
In FIG. 1, 1 is an imaging lens, 2 is an aperture, 3 is a lens driving unit, 4 is a distance detection unit, 5 is an aperture control unit, 6 is a lens side microcomputer, 7 is a communication contact for connecting the lens side and the body side, 11 is a quick return mirror, 12 is a focusing screen, 13 is a pentaprism, 14 is a half mirror, 15 is an eyepiece, 16 is a re-imaging lens, 17 is an image acquisition unit, 18 is an imaging unit, 19 is a shutter, and 20 is Sub-mirror, 21 is a body side microcomputer, 22 is a focus detection unit, 23 is a shutter control unit, 24 is a ROM, 25 is a RAM, 26 is an external storage device, 27 is a first image sensor driving unit, and 28 is a first A / D conversion. , 29 is an image processing unit, 30 is a second A / D converter, and 31 is a second image sensor driving unit.

  As shown in FIG. 1, a light beam from a subject (not shown) passes through an imaging lens 1, an aperture 2, and an open shutter 19 during still image shooting (quick return mirror 11 is up). A subject image is connected on the imaging unit 18. Here, the imaging unit 18 is a color image sensor that includes a CCD area sensor, a CMOS area sensor, or the like and has a number of pixels of about several million pixels. Note that the number of pixels of the imaging unit 18 is not limited to this.

The second image sensor driving unit 31 controls the driving of the imaging unit 18 in accordance with an instruction from the body side microcomputer 21. The second A / D converter 30 converts the analog image signal output from the imaging unit 18 into a digital image signal, performs image processing by the image processing unit 29, and stores the image in the RAM 25. These processes are executed in accordance with instructions from the body side microcomputer 21.
The light beam from the subject (not shown) is partly reflected by the quick return mirror 11 and proceeds to the pentaprism 13 side (optical viewfinder side) except during still image shooting (quick return mirror 11 is down). . This light beam forms an image on the focusing screen 12 to form a finder image (subject image). The viewfinder image is observed by the photographer through the pentaprism 13, the half mirror 14, and the eyepiece lens 15.

The half mirror 14 disposed in front of the eyepiece 15 branches a part of the light beam. The branched light beam forms a finder image (subject image) on the image acquisition unit 17 through the re-imaging lens 16. Here, the image acquisition unit 17 is a color image sensor that includes a CCD area sensor, a CMOS area sensor, or the like and has a number of pixels of about 10,000 to several million pixels.
The image acquisition unit 17 captures a subject when the quick return mirror 11 is down and the shutter 19 is closed and the image capturing unit 18 is not capturing an image.

  In this embodiment, the image acquisition unit 17 is configured to serve as an exposure control sensor, a white balance control sensor, and a subject analysis sensor in addition to moving image acquisition. If the image acquisition unit 17 is used only for the exposure control sensor, the white balance control sensor, and the subject analysis sensor, a sensor of about 1000 pixels is sufficient. However, in this embodiment, the image acquisition unit 17 acquires a moving image. Therefore, as described above, the image acquisition unit 17 requires a number of pixels of about 10,000 to several million pixels. Here, the number of pixels is not limited to the number of pixels.

  When the image acquisition unit 17 is used as an exposure control sensor, the analog image signal output from the image acquisition unit 17 is converted into a digital image signal by the first A / D converter 28 and then stored in the RAM 25. . The digital image signal stored in the RAM 25 is controlled by the shutter control unit 23 to open / close the shutter 19 or the aperture control unit 5 via the communication contact 7 and the lens side microcomputer 6 in response to an instruction from the body side microcomputer 21. This is used for calculations such as driving of the diaphragm 2.

  When the analog image signal output from the image acquisition unit 17 is used to acquire a moving image, the first A / D conversion unit 28 converts the analog image signal into a digital image signal according to an instruction from the body side microcomputer 21, and the image processing unit 29. Are stored in the RAM 25 after image processing. The first image sensor drive unit 27 controls the drive of the image acquisition unit 17 in accordance with an instruction from the body side microcomputer 21, similarly to the second image sensor drive unit 31.

Here, a part of the quick return mirror 11 is a half mirror, and the incident light beam is guided to the focus detection unit 22 in the sub mirror 20.
The focus detection unit 22 guides two images of a subject having parallax on a pair of image sensor arrays (not shown) using a light beam passing through the imaging lens 1, and relatives the two images from an image output of the image sensor array. The amount of misalignment is calculated to determine the in-focus state (so-called phase difference method). The focus detection unit 22 can obtain luminance values at a plurality of distance measuring points. This function is controlled by the body side microcomputer 21.

The program of the body side microcomputer 21 is stored in the ROM 24, and each part on the body side is under the control of the body side microcomputer 21.
Further, the digital image signal photographed by the image acquisition unit 17 or the imaging unit 18 and subjected to image processing by the image processing unit 29 is stored in the RAM 25 as described above. The digital image signal stored in the RAM 25 is output to an external storage device 26 such as a memory card and used for the user.

The body side microcomputer 21 is configured to be able to communicate with the lens side microcomputer 6 through the communication contact 7 with the interchangeable lens. On the interchangeable lens side, a lens driving unit 3 that extends the lens for focusing, and a distance detection unit 4 that detects a lens extension amount and detects a signal corresponding to a distance that the lens forms an image are provided. Yes.
Further, an aperture controller 5 is provided on the interchangeable lens side. The aperture control unit 5 drives the aperture 2 by acquiring an aperture value for obtaining an appropriate exposure amount together with the opening / closing control of the shutter 19 of the shutter control unit 23 on the body side. The lens driving unit 3, the distance detection unit 4, and the aperture control unit 5 are controlled by the lens side microcomputer 6.

FIG. 2 is a block diagram showing a modification of the embodiment shown in FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.
In the modification shown in FIG. 2, the light beam is not guided to the image acquisition unit 17 by the half mirror 14 as shown in FIG. In the modification shown in FIG. 2, a light beam emitted from the pentaprism 13 and having a light axis different from the optical axis of the eyepiece lens 15 is guided to the image acquisition unit 17. Other configurations are the same as those in FIG.

3 and 4 are explanatory diagrams illustrating a specific example of the image acquisition unit 17.
For example, as illustrated in FIG. 3, the image acquisition unit 17 is a sensor having a pixel arrangement of 400 pixels vertically and 640 pixels horizontally. A larger number of pixels is better for moving image shooting and subject analysis. However, if the number of pixels in the image acquisition unit 17 is too large, the time for acquiring data will be long. For this reason, when it is necessary to prepare for shooting quickly, it is desirable to shorten the data acquisition time as much as possible. Therefore, in order to shorten the shooting preparation time, for example, at the time of exposure calculation, as shown in FIG. 4, the pixels of the image acquisition unit 17 shown in FIG. Measure light and reduce exposure to obtain exposure data in a short time. The grouping is performed by the first image sensor driving unit 27 in accordance with an instruction from the body side microcomputer 21. As a result, when the image acquisition unit 17 is used as an exposure control sensor, exposure-related data can be acquired in a short time, and when the image acquisition unit 17 is used as a moving image acquisition sensor, a high-quality moving image can be acquired. It becomes possible to acquire.

FIG. 5 is a time chart showing the operation when the appropriate exposure value changes during moving image shooting of the image acquisition unit 17.
The appropriate exposure value may change with respect to the exposure calculation performed by the body side microcomputer 21 during moving image shooting by the image acquisition unit 17. Therefore, the appropriate exposure is calculated during moving image shooting at the timing shown in FIG.

As shown in FIG. 5, when calculating the appropriate exposure value, the image acquisition unit 17 accumulates moving image data in a short time (t1 to t2).
From time t2 to t3, the image acquisition unit 17 reads the accumulated data.
At times t3 to t4, the body side microcomputer 21 accumulates exposure calculation data (calculation of luminance data).

From time t4 to t5, the body side microcomputer 21 obtains an appropriate exposure by calculation.
After time t5, the image acquisition unit 17 performs moving image shooting at the appropriate exposure obtained at times t4 to t5. Therefore, moving image shooting is not interrupted, and moving image shooting with appropriate exposure becomes possible.
FIG. 6 is a time chart for explaining the operation when the image capturing unit 18 performs still image capturing during moving image capturing of the image acquisition unit 17. It is an example which showed each output of the image acquisition part 17 and the imaging part 18 in time series. The hatched portion indicates the data read timing.

From time t1 to t2, the image acquisition unit 17 performs data accumulation based on the incident light flux.
From time t2 to t3, the image acquisition unit 17 reads the accumulated data as an analog image signal. At the same time, the quick return mirror 11 is raised.
From time t3 to t4, the imaging unit 18 images (accumulates) a subject (not shown).

From time t4 to t5, the imaging unit 18 reads the accumulated data. At the same time, the quick return mirror 11 goes down.
At times t5 to t6, the image acquisition unit 17 accumulates data based on the incident light flux.
According to FIG. 6, when a still image is captured by the imaging unit 18 while the image acquisition unit 17 captures a moving image, the image obtained by the imaging unit 18 can be embedded between the moving images obtained by the image acquisition unit 17. At this time, when the number of pixels of the imaging unit 18 and the number of pixels of the image acquisition unit 17 are different, it is necessary to match the number of pixels (image size adjustment). In addition, the quick return mirror 11 is up / down in order to perform imaging with the imaging unit 18. When the quick return mirror 11 is up / down, neither the image acquisition unit 17 nor the imaging unit 18 can shoot. Therefore, timing deviation can be prevented by reading data from the image acquisition unit 17 and the imaging unit 18 during the mirror up and mirror down operations.

As is clear from the above description, according to FIG. 6, time t1 to t2 (image of the image acquisition unit 17), t3 to t4 (image of the imaging unit 18), t5 to t6 (image of the image acquisition unit 17). Thus, the image obtained by the imaging unit 18 can be embedded between the moving images obtained by the image acquisition unit 17.
If the still image is embedded in the moving image, the shooting time, the aperture value, and the like are not the same, the image looks different and becomes an unnatural moving image. In order to avoid such a state, the shooting conditions such as the still picture shooting time, ISO sensitivity, and aperture value may be the same as those of the moving picture shooting time, ISO sensitivity, and aperture value. The ISO sensitivity can be easily changed by providing an amplifier between the imaging unit 18 and the second A / D converter 30 in FIG. 1 and adjusting the gain of the amplifier. In addition, the ISO sensitivity can be easily changed using an amplifier built in the imaging unit 18. This operation is performed under the control of the body side microcomputer 21.

Also, when changing the shooting conditions for still images and shooting conditions for movies, change the ISO sensitivity of the still images so that the shooting time of the still images does not become too long. You may make it cancel, or prohibit still image photography during moving image photography.
FIG. 7 is a time chart showing another example when still image shooting is performed by the imaging unit 18 during moving image shooting of the image acquisition unit 17. In the example illustrated in FIG. 7, the shooting time of the imaging unit 18 is longer than the shooting time of one frame of a moving image shot by the image acquisition unit 17. As shown in the figure, the image acquisition unit 17 outputs IDn, ID (n + 4). That is, the ID (n + 1), ID (n + 2), and ID (n + 3) of the moving image are insufficient. At this time, if the moving image ID (n + 2) is created by embedding a still image as in FIG. 6, the imaging time of the imaging unit 18 is long, and thus the moving image ID (n + 1) and ID (n + 3) are still insufficient. If this is the case, the number of moving images that are insufficient is two frames, so that it feels that only two frames have stopped, resulting in an unnatural video. Therefore, the motion of the subject may be predicted from the moving images immediately before and immediately after the still image, and the number of frames of the insufficient moving image may be supplemented. A specific example in this case will be described with reference to FIG.

FIG. 8 is a time chart showing moving image processing when still image shooting takes a long time when shooting a still image (imaging unit 18) during moving image shooting (image acquisition unit 17). During the acquisition of a still image, it is impossible to acquire a moving image. Even if a still image is embedded in a moving image, the interval between moving images is increased.
In order to prevent this, apart from the process of embedding a still image using a moving image (ID (n + 2)), the moving image immediately before the still image (IDn) and the moving image immediately after (ID (n + 4)) and the still image The motion of the subject is estimated from (ID (n + 2)), moving images (ID (n + 1)) and (ID (n + 3)) are created, and the moving image acquisition interval is kept constant. These processes are performed in accordance with commands from the body side microcomputer 21 shown in FIG.

  FIG. 9 is a time chart showing an example of an image acquisition situation when a still image (imaging unit 18) is continuously shot (continuous shooting) during moving image shooting (image acquisition unit 17). FIG. 9 shows an example in which three still image shootings are performed continuously during moving image shooting. Needless to say, the number of continuous shooting may be arbitrary. In this example, the three missing moving images are interpolated by three still images. These processes are executed in response to commands from the body side microcomputer 21 shown in FIG.

  FIG. 10 is a time chart showing another example of an image acquisition situation when still images are continuously shot (continuous shooting) during moving image shooting. The example shown in FIG. 10 shows a method in which four still image shootings are performed continuously during moving image shooting, and five missing moving images are created from two adjacent still images. Needless to say, the number of continuous shooting, the number of adjacent still images, and the number of still images to be created may be arbitrary.

  As shown in FIG. 10, the first still image is used for the first moving image (ID (n + 1)) that is insufficient. Similarly, the second still image is used for the second shortage movie (ID (n + 2)). Similarly, the third still image is used for the second shortest moving image (ID (n + 4)). Similarly, the fourth still image is used for the last moving image (ID (n + 5)) that is insufficient.

  This specific example is different from the specific example shown in FIG. 9 in the following points. That is, the lacking third moving image (ID (n + 3)) estimates the movement of the subject from the second still image and the third still image, and creates the moving image (ID (n + 3)). It is. In this example, the number of moving images created is one to simplify the description, but the present invention is not limited to this, and the number of moving images created may be arbitrary. These processes are executed in response to commands from the body side microcomputer 21 shown in FIG.

6, 8, 9, and 10, when the size of the still image is different from that of the moving image, it is preferable to resize the still image so that the size of the moving image is the same.
As is clear from the above description, according to the embodiment, it is possible to provide a digital single-lens reflex camera that can shoot moving images with a digital single-lens reflex camera and can be observed on a liquid crystal display or the like.

  The present invention can be used industrially in the field of digital cameras.

It is a block diagram which shows one Embodiment of this invention. It is a block diagram which shows the modification of embodiment. It is explanatory drawing which shows the specific example of an image acquisition part. It is explanatory drawing which shows the specific example of an image acquisition part. It is a time chart for demonstrating operation | movement when a suitable exposure value changes during the video recording of an image acquisition part. It is a time chart for demonstrating operation | movement at the time of taking a still image in an imaging part during the video recording of an image acquisition part. It is a time chart for demonstrating the other example at the time of taking a still image in an imaging part during the video recording of an image acquisition part. 7 is a time chart showing an image acquisition situation when still image shooting takes a long time when shooting a still image during moving image shooting. It is a time chart which shows the image acquisition condition at the time of carrying out continuous shooting of still image photography during video recording. 10 is a time chart illustrating another example of an image acquisition situation when still image shooting is continuously performed during moving image shooting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Imaging lens, 2 ... Diaphragm, 3 ... Lens drive part, 4 ... Distance detection part, 5 ... Diaphragm control part, 6 ... Lens side microcomputer, 7 ... Communication contact, 11 ... Quick return mirror, 12 ... Focus plate, 13 DESCRIPTION OF SYMBOLS ... Penta prism, 14 ... Half mirror, 15 ... Eyepiece lens, 16 ... Re-imaging lens, 17 ... Image acquisition part, 18 ... Imaging part, 19 ... Shutter, 20 ... Submirror, 21 ... Body side microcomputer, 22 ... Focus detection , 23 ... shutter control unit, 24 ... ROM, 25 ... RAM, 26 ... external storage device, 27 ... first image sensor drive unit, 28 ... first A / D converter, 29 ... image processing unit, 30 ... 2A / D converter, 31 ... 2nd image sensor drive part.

Claims (9)

An optical viewfinder that can observe the light beam that has passed through the imaging lens;
An image acquisition means capable of moving image shooting arranged in the optical viewfinder;
Imaging means for capturing a still image from the light flux that has passed through the imaging lens;
A digital single-lens reflex camera comprising: a control unit that uses a still image obtained by the imaging unit as a moving image when the imaging unit performs still image shooting during moving image shooting of the image acquisition unit. The digital single-lens reflex camera according to claim 1.
The digital single-lens reflex camera characterized in that the control means photographs the still image and the moving image under the same photographing condition. The digital single-lens reflex camera according to claim 2.
A digital single-lens reflex camera characterized in that the photographing conditions are an aperture value and sensitivity. The digital single-lens reflex camera according to claim 1 or 2,
A digital single-lens reflex camera, wherein the control means changes the sensitivity and shoots the still image when the still image and the moving image have different shooting conditions. In the digital single-lens reflex camera according to any one of claims 1 to 4,
The control means creates and interpolates a moving image that is insufficient over the still image shooting time based on the moving image immediately before the start of the still image shooting, the moving image immediately after the end of the still image shooting, and the still image. A digital single-lens reflex camera. In the digital single-lens reflex camera according to any one of claims 1 to 4,
The control means creates a plurality of moving images based on the plurality of still images shot, and interpolates a moving image that is insufficient over the shooting time of the still images using the plurality of created moving images. A digital single-lens reflex camera. The digital single-lens reflex camera according to claim 6.
The control means creates one moving image based on at least two adjacent still images among the plurality of photographed still images, and the created moving image is insufficient according to the still image photographing time. A digital single-lens reflex camera that uses video to interpolate. In the digital single-lens reflex camera according to any one of claims 1 to 7,
A digital single-lens reflex camera, wherein the image acquisition means also serves as an exposure control sensor. In the digital single-lens reflex camera according to any one of claims 1 to 7,
The image acquisition means reads stored data when the quick return mirror is up,
A digital single-lens reflex camera characterized in that the imaging means reads stored data when the quick return mirror is down.

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