JP5463975B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus such as a digital single-lens reflex camera.

  2. Description of the Related Art In recent years, digital single-lens reflex cameras have become mainstream with a so-called live view function that captures images while observing a captured image on a liquid crystal monitor on the back of the camera. In order to enable such live view image display, there is a model in which an image sensor dedicated for live view is provided in addition to a recording image sensor (image sensor) (for example, see Patent Document 1).

JP 2007-41150 A

  With a camera equipped with an image sensor dedicated for live view as described above, photometry is possible using the image sensor dedicated for live view even during observation using the viewfinder view, so immediately after switching from viewfinder view to live view. Even if it is, the image can be displayed with an appropriate exposure at the start of the live view. On the other hand, in a model that does not have an image sensor dedicated for live view, the mirror is raised and the shutter is opened during live view, and an image captured by the image sensor for recording is displayed on the liquid crystal monitor.

  In a model that does not have an image sensor dedicated for live view, photometry immediately after switching from the viewfinder view to the live view uses a photometric value (photometric value of light branched on the viewfinder screen) by the photometric sensor. At the time of this switching, the photographer removes his face from the viewfinder. At this time, strong light from the outside may enter the finder as back-incident light from the finder opening. Usually, since the photometric sensor is disposed in the vicinity of the finder optical system, when back incident light enters from the finder, the photometric element detects a photometric value affected by the back incident light. For this reason, if back-incident light enters the viewfinder, an image may not be displayed with an appropriate exposure at the start of live view immediately after switching from the viewfinder view to the live view.

  An object of the present invention is to provide an imaging apparatus capable of displaying an image with an appropriate exposure at the start of a live view immediately after switching from a viewfinder view to a live view even when back-incident light enters the viewfinder. .

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
According to the first aspect of the present invention, an optical viewfinder (24) capable of optically observing a subject image formed by the photographing optical system (4) and a subject image formed by the photographing optical system are captured. An image pickup means (7), a display means (8) capable of observing a subject image picked up by the image pickup means by a live view, and a brightness of a subject image formed by a photographing optical system provided in the vicinity of the optical viewfinder A photometric means (32) for detecting the photometric value to obtain a photometric value, a storage means (33) for continuously storing the photometric value of the subject image obtained by the photometric means for each section of a predetermined time, and the optical Shielding means detecting means (25) for detecting the approach of the shielding object at the eyepiece position of the finder, and while the approaching of the shielding object is detected by the shielding object detection means, the one stored in the storage means A photometric value updating means (15) that deletes a photometric value for a certain period of time after being stored in the storage means, and when the approach of the shielding object is no longer detected by the shielding object detection means, the storage means When the object image observation is switched from the viewfinder view to the live view, it is traced back from the point when the approach of the shield is no longer detected by the shield detection means. Metering value control means (15) for reading out the photometric value for one section stored in the previous section from the storage means and determining the exposure of the subject image immediately after the start of the live view based on the photometric value. This is an imaging apparatus.
A second aspect of the present invention is the imaging apparatus according to the first aspect, wherein the imaging apparatus is made of a reflective material that reflects subject light that has passed through the imaging optical system (4), and a predetermined direction from a fixed position in the imaging apparatus. The finder view is fixed at a fixed position in the viewfinder view, reflects the subject light toward the optical viewfinder (24), and rotates in a predetermined direction in the live view so that the subject light is captured by the imaging means (7). (11) provided with a turning mirror for guiding to the) side, and switching the viewfinder view and the live view by turning the turning mirror in a fixed position or in a predetermined direction.
Invention of Claim 3 is an imaging device of Claim 1, Comprising: The said photometric value control means (15) is when the approach of a shield is no longer detected by the said shield detection means (25) Stops storing the photometric value in the storage means (33) and starts storing the photometric value in the storage means when the approach of the shielding object is detected by the shielding object detection means. It is what.
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  According to the present invention, there is provided an imaging device capable of displaying an image with an appropriate exposure at the start of a live view immediately after switching from the viewfinder view to the live view even when back-incident light enters the optical viewfinder. can do.

It is sectional drawing which shows the structure (at the time of mirror down) of the principal part of the camera concerning embodiment. It is sectional drawing which shows the structure (at the time of mirror up) of the principal part of the camera concerning embodiment. It is a block diagram which shows the electrical structure of a camera main body. It is a schematic diagram which shows the photometry value memorize | stored in photometry memory. It is a flowchart which shows a series of processing procedures from the imaging | photography of an object image to recording.

  Hereinafter, an embodiment of an imaging apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of main parts of a camera 1 according to the present embodiment. The camera 1 is a digital single-lens reflex camera, and includes a camera body 2 and a lens barrel 3 that is detachably attached to the camera body 2.

  The lens barrel 3 includes a plurality of photographing lenses 4 and an aperture unit 5 on which subject light A is incident. The photographing lens 4 is an optical member that refracts incident subject light A and emits it to the camera body 2 side. The diaphragm unit 5 adjusts the amount of subject light A passing through the photographing lens 4 and is controlled mechanically or electrically.

  The camera body 2 includes a mirror unit 10, a finder optical unit 20, a photometric unit 30, a shutter 6, an imaging unit 7, a liquid crystal monitor 8, and the like. Hereinafter, each part will be described.

  The shutter 6 is disposed behind the mirror unit 10. The subject light A is incident on the shutter 6 when the mirror unit 10 is rotated upward and becomes ready for photographing. The shutter 6 includes a plurality of shutter blades (not shown). The shutter 6 opens and closes shutter blades in response to a shooting instruction from a release button or the like, and the subject light A is incident on the imaging unit 7. The operation of the shutter 6 is controlled by a shutter unit (not shown).

  The imaging unit 7 is a part that captures the subject image formed by the photographing lens 4, exposes the subject light A, converts it into an electrical image signal, and outputs it to the image processing unit (see FIG. 3). The imaging unit 7 is configured by an imaging element such as a CCD or a CMOS.

  The liquid crystal monitor 8 is provided on the back surface of the camera body 2 and is configured by a color liquid crystal display that displays a subject image (reproduced image, live view image) photographed by the imaging unit 7 and information related to an operation.

  The mirror unit 10 has a rotatable main mirror 11 and a sub mirror 12. The mirror unit 10 is provided at a position where the light from the photographing lens 4 is incident, and causes the subject light A to enter the finder optical unit 20 or the shutter 6 and the imaging unit 7.

  The main mirror 11 reflects the subject light A to the finder optical unit 20. A semi-transmissive mirror having a characteristic of transmitting a part of light is used at the center of the main mirror 11. The main mirror 11 transmits part of the subject light A and causes the subject light A to enter the sub mirror 12. Further, the main mirror 11 has a rotation portion (not shown) at the end, and is configured to be rotatable upward in the camera body 2.

  The sub mirror 12 is a reflection mirror that reflects a part of the subject light A transmitted through the main mirror 11 to the distance measuring sensor 9 together with the mirror 13. The sub mirror 12 is attached to the main mirror 11 so as to be rotatable, and the sub mirror 12 is folded into the main mirror 11 by the rotation and is erected on the back side of the main mirror 11.

  The distance measuring sensor 9 is disposed in the vicinity of the sub mirror 12 and the mirror 13. This distance measuring sensor 9 detects the defocus amount of the subject image in a predetermined distance measuring area set in the screen. Based on the defocus amount detected by the distance measuring sensor 9, automatic focus adjustment is performed.

  In the finder view, the main mirror 11 and the sub mirror 12 are fixed at fixed positions shown in FIG. 1 and reflect the subject light A to the finder optical unit 20 and the distance measuring sensor 9, respectively. Due to the reflection on the finder optical unit 20, the photographer can observe the subject image with the optical finder 24. Then, when switching to the live view is performed or when a release button (not shown) is fully pressed for shooting, the main mirror 11 is rotated upward as shown in FIG. At the same time, the sub mirror 12 is rotated and folded so as to overlap the main mirror 11 (mirror up). At this time, the shutter blades of the shutter 6 also rotate, and the shutter 6 is opened. As a result, the subject light A is incident on the imaging unit 7 to enable live view or shooting for recording. As described above, in the present embodiment, the viewfinder view and the live view are switched by rotating the main mirror 11 to a fixed position or upward. The operations of the main mirror 11 and the sub mirror 12 are controlled by a mirror driving unit (not shown).

  The finder optical unit 20 includes a finder screen 21, a pentaprism 22, and an eyepiece lens 23. The finder screen 21 is disposed above the mirror unit 10, and the subject light A reflected by the mirror unit 10 is projected onto the finder screen 21 to form a subject image. Light from the subject image on the finder screen 21 is guided to the eyepiece lens 23 by the pentaprism 22, and is guided from the eyepiece lens 23 to the optical finder 24. Thus, the photographer can look into the optical viewfinder 24 and observe the subject image. The optical viewfinder 24 is disposed on the rear side of the eyepiece lens 23. The subject image projected on the finder screen 21 is also guided to the photometry unit 30 via the pentaprism 22.

  The photometric unit 30 includes a photometric optical system 31 such as a prism or a lens and a photometric sensor 32. The photometry unit 30 causes the branched light from the pentaprism 22 to enter the photometry sensor 32. The photometric sensor 32 functions as photometric means for detecting the brightness (luminance) of the subject light image based on the incident branched light and obtaining a photometric value. The photometric value obtained by the photometric sensor 32 is stored in the photometric memory 33. In the photometric memory 33, the photometric values obtained by the photometric sensor 32 are continuously stored for each section consisting of a predetermined time. Storage and deletion of the photometric value in the photometric memory 33 will be described later.

  In addition, an approach detection unit 25 that detects whether the photographer is approaching or not approaching the optical viewfinder 24 is provided at the eyepiece position of the optical viewfinder 24 on the back surface of the camera body 2. The approach detection unit 25 is composed of an eye sensor equipped with an infrared sensor, and when a photographer (mainly a face) approaches the optical viewfinder 24, a detection signal is output to the control unit 15 to detect the photographer's approach. If not, a non-detection signal is output (or no signal is output). That is, the approach detection unit 25 functions as a shielding object detection unit that detects the approach of the shielding object at the eyepiece position of the optical viewfinder 24.

  Although not shown in FIG. 1, the camera body 2 is provided with various dials, levers, switches, buttons, and the like as operation input means (operation members) by the photographer. In the present embodiment, to simplify the description, switching from the viewfinder view to the live view is performed by a dial operation (not shown). However, switching from the viewfinder view to the live view may be performed by other operations. For example, the live view mode may be set by a dial operation, and the live view may be started when the release button 26 is fully pressed in this state.

  Next, the electrical configuration of the camera body 2 will be described with reference to the block diagram shown in FIG. In FIG. 3, the same parts as those in FIG. Hereinafter, each part will be described.

  The image processing unit 14 performs analog and digital processing, such as noise removal, A / D conversion, color correction processing, size change, and encoding, on the image signal output from the imaging unit 7 to obtain a final image. Create data. This image data is temporarily stored in the DRAM 18.

  The EEPROM 16 is a non-volatile memory that retains stored information even when the camera 1 is turned off, and stores input information such as user settings and custom settings.

  The ROM 17 stores a program necessary for the operation and control of the camera 1 as well as initial values and setting values necessary for executing this program.

  The DRAM 18 is a volatile memory in which stored information is erased when the power of the camera 1 is turned off. In addition to the above-described image data, the data necessary for the image processing unit 14 and the control unit 15 to perform processing. Is temporarily stored.

  The memory card I / F (interface) unit 19 is a writing / reading device having a function of recording image data stored in the DRAM 18 on the memory card 27 and reading out image data recorded on the memory card 27. is there. A memory card 27 is detachably attached to a memory card slot (not shown) of the memory card I / F unit 19.

  The control unit 15 is a circuit that controls the overall operation of the camera 1 and is configured by a microprocessor. Hereinafter, various functions executed by the control unit 15 will be described.

  When the release button 26 is half-pressed, the control unit 15 calculates the lens driving amount based on the defocus amount of the subject image detected by the distance measuring sensor 9. By transmitting information on the lens driving amount to a lens control unit (not shown) on the lens barrel 3 side, focus adjustment is performed by the lens internal motor of the lens barrel 3. Alternatively, the in-body motor (not shown) may be driven based on the lens driving amount so that the driving force is transmitted to the lens barrel 3 side through the coupling mechanism to adjust the focus.

  While the approach detection unit 25 detects the approach of the photographer, the control unit 15 deletes the photometric value for one section stored in the photometric memory 33 after a predetermined time has elapsed since the photometric memory 33 stores the photometric value. Functions as a photometric value updating means. Further, as a function of the photometric value update unit, the control unit 15 stops storing the photometric value in the photometric memory 33 when the approach detection unit 25 no longer detects the approach of the photographer, and the approach detection unit 25 When the approach of the photographer is detected, storage of the photometric value in the photometric memory 33 is started (resumed). Here, storage and deletion of the photometric value in the photometric memory 33 will be described.

  FIG. 4 schematically shows the photometric values stored in the photometric memory 33. As shown in FIG. 4, in the photometric memory 33, photometric values obtained by the photometric sensor 32 are continuously stored in time series for each section consisting of time t1. The control unit 15 deletes the photometric value for one section stored in the photometric memory 33 after the time t2 has elapsed since it was stored in the photometric memory 33. For example, the photometric values of the n-2 section are deleted when the time t2 has elapsed since the storage of the one section has ended, that is, when the storage of the photometric values of the n section has ended. Thereafter, every time t2 elapses, the stored photometric values for one section are sequentially deleted, and the photometric memory 33 stores the newest two sections of photometric values. However, the time t2 from the end of the photometric value storage to the deletion is not limited to this example, and may be longer. All the photometric values stored in the photometric memory 33 are deleted when the camera 1 is turned off.

  When the approach detection unit 25 no longer detects the approach of the photographer, the control unit 15 holds the photometry value stored in the photometry memory 33 so as not to be deleted, and then observes the subject image. Is switched from the viewfinder view to the live view, the metering value for one section stored in the previous section from the time when the approach of the photographer is no longer detected by the approach detection unit 25 is stored in the metering memory 33. It functions as a photometric value control means that reads out and determines the exposure of the subject image immediately after the start of the live view based on this photometric value.

  The function of this photometric value control means will be described with reference to FIG. In FIG. 4, it is assumed that the approach detection unit 25 no longer detects the approach of the photographer while the measurement values in the n section are stored. At this time, the control unit 15 holds the photometric value stored in the photometric memory 33 so as not to be deleted as a function of the photometric value control means. In addition, as a function of the photometric value update unit, storage of the photometric value in the photometric memory 33 is stopped. Thereafter, when the observation of the subject image is switched from the viewfinder view to the live view, as a function of the photometric value control means, one step back from the time when the approach detection unit 25 no longer detects the approach of the photographer. The photometric value for one section stored in the section, that is, the n−1 section is read from the photometric memory 33.

  As described above, the photometry immediately after switching from the viewfinder view to the live view uses the photometry value obtained by the photometry sensor 32. At the time of this switching, the photographer removes his face from the optical viewfinder 24. At this time, if intense light from the outside enters the finder from the opening of the optical finder 24 as back-incident light, the photometric sensor 32 detects a photometric value affected by the back-incident light. Therefore, when the approach detection unit 25 no longer detects the photographer's approach, that is, the photometric values in the n section shown in FIG. 4 are affected by the back incident light. On the other hand, the photometric value for one section stored in the previous n-1 section retroactively from the time when the approach of the photographer is no longer detected by the approach detection unit 25 is not affected by the back incident light. Therefore, by determining the exposure of the subject image based on the photometric value in this section, the image can be displayed with an appropriate exposure at the start of the live view immediately after switching to the live view.

  Next, in the camera 1 of the present embodiment, a series of processing procedures from imaging to recording of a subject image will be described with reference to the flowchart of FIG. Here, switching from the viewfinder view to the live view and control of the photometric value will be mainly described, and description of other processes will be omitted as appropriate. The process of this flowchart starts when the photographer presses the release button 26 halfway. Further, it is assumed that the photographer is observing the subject image in the viewfinder view when the processing of the flowchart starts.

  In step S <b> 101, the photometric sensor 32 detects the brightness of the subject light image to obtain a photometric value, and stores the photometric value in the photometric memory 33.

  In step S <b> 102, the distance measurement sensor 9 detects the defocus amount of the subject image in a predetermined distance measurement area set in the screen, and transmits this to the control unit 15.

  In step S103, the control unit 15 determines whether or not the release button 26 has been fully pressed. If “NO” in the determination in step S103, the process proceeds to step S104, and it is determined whether the approach detection unit 25 detects the approach of the photographer. If the determination in step S104 is YES, the process returns to step S101. That is, while the approach of the photographer is detected, the finder view state is maintained, and thus photometry and distance measurement are repeated for recording photographing.

  On the other hand, when the determination in step S104 is NO, that is, when the approach detection unit 25 no longer detects the approach of the photographer, the process proceeds to step S105, stops storing the photometric value in the photometric memory 33, and already stores it. The photometric memory 33 is controlled so that the photometric value being deleted is not deleted (holding the photometric value).

  Subsequently, in step S106, the control unit 15 determines whether or not there is an instruction to switch from the viewfinder view to the live view by an operation input by the photographer. If “NO” in the determination in step S106, the process returns to step S104. If the determination in step S106 is YES, the process proceeds to step S107, and the photometric value for one section stored in the previous section is traced back from the time when the approach detection unit 25 no longer detects the approach of the photographer. Read from the photometric memory 33.

  In step S108, the control unit 15 controls a mirror driving unit (not shown) to rotate the main mirror 11 and the sub mirror 12 upward to retract them from the optical path (mirror up). In step S109, the control unit 15 controls a shutter unit (not shown) to open the shutter.

  Subsequently, in step S110, the control unit 15 displays an image of the subject image captured by the imaging unit 7 on the liquid crystal monitor 8 (live view start). At the start of live view, the exposure of the subject image is determined based on the photometric value read in step S107. For this reason, an image is displayed with an appropriate exposure at the start of the live view immediately after switching to the live view.

  In the live view, the image is displayed by repeatedly reading out the image data generated by the image processing unit 14 at a predetermined cycle. Control for determining the exposure of the subject image based on the photometric value read in step S107 is performed for 1 to 2 seconds or several frames from the start of the live view, and thereafter, photometric measurement of image data obtained by imaging with the imaging unit 7 is performed. The exposure of the subject image is determined based on the value. For this reason, immediately after the start of the live view, images with appropriate exposure are continuously displayed until an image is displayed according to the photometric value of the imaging unit 7.

  In step S <b> 111, the control unit 15 performs photometry and focus adjustment based on the image data generated by the image processing unit 14. During live view, focus adjustment is performed by contrast AF. However, after the live view is started, for example, when the release button 26 is half-pressed, the live view may be temporarily interrupted to perform focus adjustment by photometry by the photometry sensor 32 and phase difference AF by the distance measurement sensor 9. .

  In step S112, the control unit 15 determines whether or not the release button 26 has been fully pressed. If “NO” in the determination in step S112, the process proceeds to step S113, and it is determined whether or not there is an instruction to switch from the live view to the finder view by an operation input of the photographer (live view cancellation). If YES in step S113, the process returns to step S101. If NO in step S113, the process returns to step S110 and the live view is continued.

  In addition, when the determination in step S112 is YES, or the determination in step S103 is YES, that is, when the release button 26 is fully pressed, the control unit 15 proceeds to step S114 and executes an imaging process. Here, the main mirror 11 and the sub mirror 12 that have been rotated upward are mirror-downed, and after performing photometry by the photometry sensor 32 and focus adjustment by phase difference AF by the distance measurement sensor 9, imaging is performed by the imaging unit 7. Do. Then, the image processing unit 14 generates image data. Next, in step S 115, the image data is recorded on the memory card 27 via the memory card I / F unit 19.

According to the said embodiment, there exist the following effects.
(1) In this embodiment, when the approach of the photographer is not detected, the photometry value stored in the photometry memory 33 is held so as not to be deleted, and when the viewfinder view is switched to the live view after that, The exposure of the subject image immediately after the start of the live view is determined based on the photometric value for one section stored in the previous section retroactively from the time when the approach of the photographer is no longer detected. For this reason, when the photographer moves away from the viewfinder, the exposure of the subject image immediately after switching from the viewfinder view to the live view is reversed even if strong external light enters the viewfinder as back-incident light. Since it is determined based on a photometric value that is not affected by incident light, an image can be displayed with an appropriate exposure even immediately after the start of live view immediately after switching from the viewfinder view to the live view.

(2) Since the storage of the photometric value in the photometric memory 33 is stopped when the approach of the photographer is not detected, the photometric value affected by the back incident light is prevented from being stored in the photometric memory 33. be able to. In addition, since the photometry value is stored in the photometry memory 33 when the approach of the photographer is detected, even when the photographer temporarily removes his face from the viewfinder during the viewfinder view, The photographer can store the photometric value in the photometric memory 33 again simply by returning to the viewfinder view.

(Deformation)
Without being limited to the embodiment described above, the present invention can be variously modified and changed as described below, and these are also within the scope of the present invention.
(1) In this embodiment, an example in which the viewfinder view is switched to the live view by the photographer's operation has been described. However, the present invention is not limited to this, and the viewfinder is automatically detected if the approach detection unit 25 does not detect the approach of the photographer. You may make it switch from a view to a live view.

(2) In this embodiment, although the example which comprised the proximity detection part 25 used as a shield detection means by the eye sensor provided with the infrared sensor was shown, not only this but a shield detection means is a touch panel, a temperature sensor, etc. You may comprise.

  Moreover, although the said embodiment and modification can be used in combination suitably, since the structure of each embodiment is clear by illustration and description, detailed description is abbreviate | omitted. Furthermore, the present invention is not limited by the embodiment described above.

  1: Camera, 2: Camera body, 3: Lens barrel, 7: Imaging unit, 8: Liquid crystal monitor, 9: Distance sensor, 10: Mirror unit, 11: Main mirror, 12: Sub mirror, 14: Image processing unit , 15: control unit, 24: finder, 25: approach detection unit, 30: photometry unit, 32: photometry sensor, 33: photometry memory

Claims (3)

An optical viewfinder capable of optically observing a subject image formed by the photographing optical system through a viewfinder view;
Imaging means for imaging a subject image formed by the imaging optical system;
Display means capable of observing the subject image captured by the imaging means by a live view;
A photometric means provided in the vicinity of the optical viewfinder for detecting a brightness of a subject image formed by a photographing optical system and obtaining a photometric value;
Storage means for continuously storing the photometric value of the subject image obtained by the photometric means for each section consisting of a predetermined time;
Shielding object detection means for detecting the approach of the shielding object at the eyepiece position of the optical viewfinder;
A photometric value updating means for deleting a photometric value for one section stored in the storage means after the predetermined time has elapsed while the approach of the shielding object is detected by the shielding means; ,
When the approach of the shielding object is no longer detected by the shielding object detection unit, the photometric value stored in the storage unit is held so as not to be deleted, and the observation of the subject image is switched from the viewfinder view to the live view. When the occluding object detection means no longer detects the approach of the occluding object, the metering value for one section stored in the immediately preceding section is read from the memory means and live based on the metricing value. Photometric value control means for determining the exposure of the subject image immediately after the start of the view;
An imaging apparatus comprising: The imaging apparatus according to claim 1,
It consists of a reflective material that reflects subject light that has passed through the imaging optical system, and is configured to be rotatable in a predetermined direction from a fixed position in the imaging device. A rotating mirror that guides the subject light to the imaging means side by rotating in a predetermined direction in the live view,
Switching the viewfinder view and the live view by rotating the rotating mirror in a fixed position or a predetermined direction,
An imaging apparatus characterized by the above. The imaging apparatus according to claim 1,
The photometric value control means includes
When the approach of the shielding object is no longer detected by the shielding object detection means, the storage of the photometric value to the storage means is stopped, and when the approach of the shielding object is detected by the shielding object detection means, the memory is stored. Starting to store photometric values in the means,
An imaging apparatus characterized by the above.

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