JP2006126443A - Photographing device and photographing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a photographing device capable of satisfactorily detecting a shake and performing a photographing operation, and to provide a photographing system. <P>SOLUTION: The photographing device includes: a first imaging element 7 disposed on the optical axis of light emitted from a photographing optical system that outputs a signal for forming a photographic image; and a second imaging element 8 disposed outside the optical axis and used to receive the light. The photographing device detects a shake of a photographing device bases on an output from the second imaging element 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image capturing apparatus and an image capturing system having an image stabilization function, and more particularly to camera shake detection.

  Conventionally, when a user performs shooting, there is a problem that it is difficult to determine a composition before shooting mainly due to a user's camera shake, or that a captured image is deteriorated due to camera shake during shooting. Thus, a technique for detecting a user's hand shake and correcting it has been proposed. For example, the techniques described in Patent Documents 1 to 3 are given as typical examples.

  In the first conventional example shown in Patent Document 1, a vibration gyro for detecting an angular velocity generated by a user's camera shake is provided in an interchangeable lens for a single-lens reflex camera. A device (image) that continuously corrects the displacement (image blur) of the subject image caused by camera shake by moving a part of the lens group in the interchangeable lens at high speed in a direction substantially orthogonal to the photographing optical axis. Shake correction means) has been proposed.

  In the second conventional example shown in Patent Document 2, in a television camera that forms a subject image with an image sensor, image blur of the subject image is detected using an output signal of the image sensor that forms a captured image, Similar to the first conventional example, there has been proposed a technique for correcting image blur by driving image blur correction means provided in the photographing optical system.

Further, the third conventional example shown in Patent Document 3 is a video camera that forms a subject image with an image sensor as in the second conventional example, and uses an output signal of the image sensor that forms a captured image. There has been proposed an apparatus that detects the touch of a subject image and corrects the displacement of the subject image by moving the image sensor at a high speed in a direction orthogonal to the optical axis.
JP-A-3-188430 (pages 2 to 3, FIG. 2, FIG. 3 etc.) Japanese Patent Laid-Open No. 1-231483 (page 2, lower left column to page 3, lower right column, FIG. 1, etc.) JP-A-2-170681 (upper right column on page 3 to lower left column on page 4, FIGS. 1 to 5 etc.)

  However, in the first conventional example, since the interchangeable lens is provided with an image blur correction (anti-shake) function, image blur correction cannot be performed when a photographic lens having no anti-shake function is attached.

  In addition, it is possible to provide a shake detection device and an image shake correction mechanism in all the interchangeable lenses, but for a user who owns a plurality of interchangeable lenses, a plurality of substantially the same functions are provided. The camera shake detection device is not preferable, and the manufacturing cost of the camera shake detection device and the image shake correction function mounted on the interchangeable lens is high. The burden increases. Therefore, ideally, it is desirable to include the shake detection device in the photographing device.

  On the other hand, the displacement of the subject image (image blur) that occurs when camera shake due to predetermined camera shake occurs is largely dependent on the focal length of the attached photographic lens because the camera shake is often mainly in the rotational direction. Tend to. In particular, when a photographing lens having a long focal length is attached, a large image displacement correction is required. In this case, the method of driving the image pickup device itself as in the third conventional example is limited to the light receiving area of the image pickup device, so that accurate shake detection cannot be performed and it is not possible to cope with correction of a large image displacement. Have.

  In the second conventional example, camera shake is detected using an imaging signal output from an imaging device for generating a captured image provided in the imaging apparatus. However, when image blur correction is performed by continuously reading out image signals from the image sensor, it is necessary to perform signal processing for camera shake detection in addition to signal processing for forming a captured image. Signal processing time becomes long, and high-speed shooting and continuous shooting are difficult.

  In addition, it is necessary to continuously read out the charge before and after the generation of the captured image, and the image sensor must be in a dark state. However, since the camera shake is performed by the image sensor, there is a high-luminance subject in the screen. There is a problem of generating smears when placed. For this reason, it becomes difficult to generate a good still image.

  An exemplary object of the present invention is to provide a photographing apparatus and a photographing system that are provided with shake detection means in the photographing apparatus and are capable of performing good shake detection and photographing operations.

  In addition, another exemplary purpose is to realize a photographing apparatus and a photographing system that can perform good shake detection and photographing operation even when applied to photographing apparatuses such as a single-lens reflex camera, a digital camera, and a video camera. There is to do.

  An imaging apparatus as one aspect of the present invention is an imaging apparatus that generates a captured image based on an output signal of a first imaging element disposed on an optical axis of light from an imaging optical system, A second imaging device that is disposed at a position other than the top and receives light, and a detection unit that detects shake of the imaging device based on an output signal of the second imaging device.

  According to the present invention, since the shake detection is performed by the second image sensor provided in a position other than the optical axis of the light from the photographic optical system, the shake is detected by the first image sensor. Compared to the case, it is possible to realize a photographing apparatus and a photographing system capable of performing good shake detection and photographing operation without being affected by the photographing operation.

  In addition, since the shake detection signal is not output from the first image sensor that generates the captured image, the processing speed for generating the captured image can be improved, and deterioration of the image quality of the captured image can be prevented.

  Optimal shooting operation can be realized.

  Examples of the present invention will be described below.

  FIG. 1 is a cross-sectional view of a single-lens reflex camera which is an example of a photographing apparatus and a camera system according to the present invention. The photographing apparatus of this embodiment includes a camera body 100 and a lens that is interchangeably attached to the camera body 100. The apparatus 101 is comprised. In addition to the single-lens reflex camera, the present invention can also be applied to a photographing apparatus such as a camera integrated with a lens apparatus, a digital camera, or a video camera.

  Reference numeral 101 denotes a lens apparatus 101, 11 a zoom lens unit, 12 a correction lens unit, and 13 a focus lens unit. These lens units constitute a photographic lens. Reference numeral 14 denotes an actuator that drives the correction lens unit 12 for image blur correction. Reference numeral 15 denotes a ROM that stores data output from the lens apparatus 101, control signals output from the camera body 100, detection / calculation data, and the like.

  Reference numeral 100 denotes a camera body, 2 is a quick return mirror, 3 is a sub mirror for focus detection, 4 is a finder optical system, 5 is a focus detection optical system, 6 is a shutter, 7 is a first image sensor, and 8 is a second mirror. The image sensor 9 is a camera CPU. The first and second image sensors 7 and 8 are composed of a CCD sensor, a CMOS sensor, or the like.

  As shown in FIG. 1, in the stage before the photographing operation, the light from the subject imaged on the first image sensor 7 arranged on the planned focal plane by the lens device 101 is reflected by the quick return mirror 2. Part of the light is reflected and guided to the finder optical system 4 (optical axis AXL1 to optical axis AXL2), and part of the light that passes through the quick return mirror 2 is reflected by the sub-mirror 3 and guided to the focus detection optical system 5. Used for focus detection (optical axis AXL1 to optical axis AXL3).

  In the present embodiment, the light from the subject is observed by the user through the finder optical system 4 and the optical axis of the photographing optical system is in the same stage before photographing as when the focus is detected by the focus detection optical system 5. A shutter 6 is disposed in a light-shielding state in front of the first image sensor 7 disposed in the vicinity, and the image capturing surface of the first image sensor 7 is in a dark state.

  Further, a part of the light from the subject is simultaneously guided onto the second image sensor 8 arranged at a position apart from the optical axis of the lens device 101 without passing through the quick return mirror 2 and the sub mirror 3. A subject image is also formed on the second image sensor 8. More specifically, the second image sensor 8 has an optical axis AXL1 that goes straight through the lens device 101, an optical axis AXL2 that is reflected by the quick return mirror 2, and an optical axis AXL3 that is reflected by the sub mirror 3. Placed in position. In other words, light from the subject that is not reflected by the quick return mirror 2 and the sub mirror 3 forms an image on the second image sensor 8.

  On the other hand, the lens apparatus 101 is composed of three lens units 11, 12, and 13 as a whole. By moving the correction lens unit 12 in the direction substantially orthogonal to the optical axis AXL 1 by the actuator 14, the displacement of the subject image (image Correct the shake). The subject image formed on the second image sensor 8 is transferred in time series to the camera CPU 9 of the camera body 100, where the temporal displacement of the subject image is decomposed into horizontal and vertical components to shake the subject. It is detected as information (first shake information).

  Further, the lens device 101 is provided with a mechanical or physical shake detection device (vibration gyro (angular velocity sensor), acceleration sensor, etc.) 30, and the shake detection device 30 uses the shake (second shake information) of the photographing apparatus. Is detected.

  The shake information of the subject image and the shake information of the photographing apparatus are stored in the ROM 15 in the lens apparatus 101 and converted into drive information for driving the actuator 14 based on constant data for image shake correction. Then, drive information is output to the actuator 14, and the correction lens unit 12 is instantaneously driven in a direction substantially orthogonal to the optical axis AXL1 to correct the shake of the subject image.

  Next, FIG. 2 shows a state during the photographing operation of the photographing apparatus of the present embodiment. In FIG. 2, the quick return mirror 2 and the sub mirror 3 are retracted from the optical axis AXL <b> 1 of the lens device 101, that is, out of the photographing optical path. Further, the shutter 6 is in an open state, and the subject image is formed on the imaging surface of the first image sensor 7. By continuing this state for a predetermined time, the subject image is photoelectrically converted by the first image sensor 7 and output to the camera CPU 9 as an image signal.

  At this time, the subject image is continuously formed on the imaging surface of the second imaging element 8 from the state before the photographing operation, and the camera CPU 9 continuously detects the shake information of the subject image (first image). Shake information) is detected. Based on the first shake information and the second shake information detected by the shake detection device 30, the lens device 101 continuously drives the correction lens unit 12 in a direction substantially orthogonal to the optical axis AXL1. Shake correction.

  Thereafter, when the stage after the photographing operation is reached, the state returns to the state shown in FIG. 1 again, and the first image sensor 7 is shielded by the shutter 6 and becomes in a dark state. In addition to preparing for the next shooting by resetting, noise components such as a dark current generated in a dark state are detected to remove noise components generated in the shot image and form a high-quality still image.

  Even in this state, a part of the subject image formed by the photographing optical system (lens device 101) is continuously formed (formed) on the second image sensor 8. Therefore, even when the shutter 6 is closed and the first image sensor 7 is shielded to be in a dark state (while a captured image is being generated), the shake of the subject image is continuously detected to correct the image blur. The next shooting operation is possible.

  FIG. 3 is a plan view of the arrangement of the first image sensor 7 and the second image sensor 8 in this embodiment as viewed from the direction of the lens device 101. In FIG. 3, reference numeral 10 denotes an effective image circle (image circle region) including the light receiving surface of the lens device 101. The lens device 101 is designed with an effective image circle that includes the diagonal dimension of the first image sensor 7, and an area within the effective image circle 10 that can be always exposed as shown in FIG. It exists within.

  In the present embodiment, effective shake detection is realized by arranging the second image sensor 8 that can be used for shake detection in such an effective image circle 10 in the photographing apparatus. Therefore, the second image sensor can receive light from the subject regardless of the positions of the quick return mirror 2 and the sub mirror 3.

  Next, the imaging system of the present embodiment will be described based on the operation flowchart shown in FIG. First, when the power switch of the photographing apparatus is turned on (S101), the photographing operation and the image stabilization function are activated (S102). The image stabilization function may be activated automatically when the photographing apparatus is turned on, or may be configured to activate the image stabilization function arbitrarily using an IS switch or the like.

  Next, as the image stabilization function is activated, the second image sensor 8 starts to detect the shake of the subject image formed on the image plane and continuously outputs the first shake information of the subject image. Output to the camera CPU 9 (S103), and at the same time, the second shake information of the photographing apparatus detected by the shake detection device 30 is also output to the camera CUP (S104). The first and second shake information is stored in the ROM 15 in the lens apparatus 101, and is converted into drive information for driving the actuator 14 based on constant data for image shake correction. Then, the drive information is output to the actuator 14, and the correction lens unit 12 is instantaneously driven in a direction substantially orthogonal to the optical axis AXL1 to correct the shake of the subject image.

  Thereafter, it is determined whether or not the first stroke SW1 of a release button (not shown) is turned on, and a shooting preparation operation is performed (S106). When SW1 is ON, photometry by the photometry unit and focus adjustment by the focus detection unit are performed, and at the same time, an exposure value (aperture value, shutter speed, etc.) is determined (S107). Thereafter, it is determined whether or not the second stroke SW2 of the release button is turned on. When SW2 is turned on, the quick return mirror 2 and the sub mirror 3 are retracted from the optical axis AXL1, and the shutter 6 is moved to perform photographing. Thereafter, the subject image formed on the first image sensor 7 is photoelectrically converted and output as an imaging signal, subjected to various image processing and the like, stored in a memory (not shown), and the like for the first shooting. The imaging element 7 is initialized.

  It is output from the second image sensor 8 before this photographing operation (when the photographing apparatus is activated), through a photographing preparation operation (SW1 is ON) and a photographing operation (SW2 is ON) until the next photographing operation. Based on the first shake information and the second shake information output from the shake detection device 30, image blur correction (anti-shake) is always performed (that is, the shooting operation immediately before the shooting operation and the next shooting operation). Step 103 to step 105 are repeatedly executed, and image stabilization is always performed).

  As described above, in this embodiment, the planned focal plane of the photographing optical system is on the optical axis AXL1 (near) of the lens apparatus 101 and is shielded by the shutter 6 before and after the photographing operation, and is exposed only during photographing. The first image sensor 7 is disposed at a position where the first image sensor 7 is located, and the first image sensor 7 is located at a position apart from the optical axis AXL1 of the lens device 101 and at a position where a subject image can be continuously formed before and after the shooting operation and during shooting. Two image sensors 8 are arranged. Then, an image signal formed by the second image sensor is output in time series, and the shake of the subject image is continuously detected.

  Therefore, as compared with the conventional method in which shake is detected by the first image sensor 7, shake detection can be performed without being affected by the shooting operation, and shooting capable of performing accurate and stable shake detection and shooting operation is possible. An apparatus and a photographing system can be realized.

  In addition, since the shake detection signal is not output from the first image sensor 7 because the shake detection is not performed by the first image sensor 7 that generates the captured image, in other words, the subject imaged on the first image sensor 7 The processing speed of the image signal output process is improved, the occurrence of smearing and the like are prevented, and a good captured image can be obtained.

  In addition, since the second image sensor 8 directly measures the time-series displacement of the subject image, not only the subject whose shake is mainly the rotation component but also the parallel due to the parallel eccentricity of the camera and the entire interchangeable lens. It is possible to effectively perform shake detection mainly including an eccentric component, thereby improving the accuracy of image blur correction control.

  Further, conventionally, in a single-lens reflex camera, it has been difficult to detect the shake of the subject image before and after the shooting operation and during the shooting, but the shake detection can be performed regardless of the shooting operation. Therefore, in a single-lens reflex camera system in which an interchangeable lens device (photographing lens) can be selectively used, an image stabilization function can be used in combination with many photographing lenses.

  Next, FIG. 5 is a block diagram showing the configuration of the photographing apparatus according to the second embodiment of the present invention. In this embodiment, the second image pickup device 8 in the first embodiment is within the effective image circle 10 including the light receiving surface of the lens device 101 (approximately the same as the first image pickup device 7 on the planned focal plane of the lens device 101). The light guide member 21 is disposed at an arbitrary position in the space (and within the effective image circle 10) from the exit surface of the lens device 101 to the planned focal plane, and the lens is disposed in the photographing device. A portion conjugate with the planned focal plane of the apparatus 101 is provided, and the second image sensor 8 is disposed in this portion.

  In FIG. 5, reference numeral 21 denotes a light guide member. The light guide member 21 reaches the first image sensor 7 arranged in the vicinity of the optical axis AXL <b> 1 of the lens device 101 among the light of the subject emitted from the lens device 101. The effective image circle 10 is disposed at a position that does not affect the luminous flux to be guided and guides the subject image in the effective image circle 10 of the lens device 101 to the second image sensor 8. Other configurations Since it is the same as that of the first embodiment, description thereof is omitted.

  As described above, in this embodiment, as described above, a part of light from the photographing lens toward the effective image circle (image circle region) 10 including the light receiving surface of the first image sensor 7 is converted into the second image sensor. The light guide member 21 led to 8 is disposed, and the second image sensor 8 is configured to detect shake.

  For this reason, the second image sensor 8 is not limited to the effective image circle 10 and can be disposed at an arbitrary position suitable for the design specifications and the like. Therefore, in addition to the operation and effect of the first embodiment, the use efficiency of the arrangement space is improved, and the apparatus can be downsized.

  As described above, in the first and second embodiments, the constant stored in the ROM of the lens device 101 is a constant corresponding to the shake correction amount per unit driving amount of the correction lens unit in the lens device 101. It is a constant having a property that varies depending on the focal length of the lens device 101 to be mounted, the focal length of the correction lens unit, and the like. Normally, in a zoom lens unit or the like, this constant changes depending on the zoom position, but also changes to some extent depending on the focus adjustment position. Therefore, data is stored in the ROM so as to change depending on the state of the lens device 101. Is desirable.

  In addition, as a shake correction unit including the correction lens unit 12 and the actuator 14 provided in the lens device 101, a part of the lens units of the lens device 101 is moved in a direction substantially orthogonal to the optical axis. For example, a variable apex angle prism may be provided in the lens apparatus 101 and the shake may be corrected by changing the apex angle of the variable apex angle prism.

  Further, the lens device 101 is provided with a lens CUP, and each lens unit is controlled based on a signal output from a camera CPU 9 to be described later. The second shake information from the shake correction device 30 and the camera body 100 It is also possible to configure such that the lens CUP performs calculation / control based on one shake information.

  The second imaging element 8 detects shake of a parallel eccentric component that cannot be detected by the shake detection device 30 such as a mechanical or physical vibration gyro, and the shake detection device 30 uses the shake of the imaging device. However, the image blur correction control based on only the shake detection by the second image sensor 8 may be performed.

1 is a configuration block diagram of a photographing apparatus according to Embodiment 1 of the present invention (before photographing operation). 1 is a configuration block diagram of a photographing apparatus according to a first embodiment of the present invention (during photographing operation). FIG. 3 is an explanatory diagram of arrangement of first and second imaging elements of the imaging apparatus according to the first embodiment of the present invention. FIG. 3 is an operation flowchart of the image capturing apparatus (imaging system) in Embodiment 1 of the present invention. FIG. 5 is a configuration block diagram of a photographing apparatus according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting lens 2 Quick return mirror 3 Submirror 7 1st image sensor 8 2nd image sensor 9 Camera CPU
10 Image circle region 21 Light guide member

Claims (10)

An imaging device that generates a captured image based on an output signal of a first image sensor disposed on an optical axis of light from an imaging optical system,
A second imaging element that is disposed at a position other than on the optical axis and receives the light;
An imaging apparatus comprising: a detecting unit that detects a shake of the imaging apparatus based on an output signal of the second imaging element. Having a mirror member movable in and out of the optical path from the photographing optical system;
The imaging apparatus according to claim 1, wherein the second imaging element receives light that is not reflected by the mirror member.   3. The photographing apparatus according to claim 1, wherein the light receiving surface of the second image sensor is disposed in an image circle region including the light receiving surface of the first image sensor.   The imaging apparatus according to claim 1, further comprising a light guide member that guides a part of light toward an image circle region including a light receiving surface of the first image sensor to the second image sensor. . A shutter that controls exposure of the first image sensor;
5. The photographing apparatus according to claim 1, wherein the second image sensor receives the light regardless of whether the shutter is opened or closed. A mirror member that moves in and out of the optical path from the imaging optical system;
The imaging apparatus according to claim 1, wherein the second image sensor receives the light regardless of a position of the mirror member.   The photographing apparatus according to claim 1, further comprising a control unit that performs image blur correction control based on a shake detected by the detection unit.   The control means performs the image shake correction control based on a first shake detected by the detection means and a second shake detected by a mechanical or physical shake detection method. The imaging device according to claim 7. The photographing apparatus according to any one of claims 1 to 8,
An imaging system comprising: an interchangeable lens attached to the imaging apparatus.   The photographing system according to claim 8, wherein the interchangeable lens includes an optical element that is driven for image blur correction.

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