JP4307185B2 - Camera and lens device - Google Patents

Description

  The present invention relates to an image blur correction device mounted on a camera or lens device capable of moving image shooting and still image shooting.

  2. Description of the Related Art Conventionally, cameras and lens devices are often equipped with an image blur correction device in order to suppress image blur due to so-called camera shake.

Patent Document 1 proposes a camera in which the control torque (anti-vibration control characteristics) of the correction optical system is switched in order to perform an appropriate image shake correction operation during moving image shooting and still image shooting. Yes.
JP-A-6-22205 (paragraphs 0045 to 0048, FIG. 2 and FIG. 14)

  However, just by switching the control torque of the correction optical system between moving image shooting and still image shooting as in the camera proposed in Patent Document 1, the frequency characteristics (correction) required for moving image shooting and still image shooting are corrected. Since the frequency (lower limit or upper limit frequency of the shake signal for driving the optical system) is different, a sufficiently appropriate image shake correction operation cannot be performed.

  It is an object of the present invention to provide an image blur correction device capable of performing a more appropriate image blur correction operation at the time of moving image shooting and still image shooting, and a lens device, a camera, and a camera system provided with the image blur correction device. Yes.

In order to achieve the above object, the present invention is a camera having a switching means for switching between moving image shooting and still image shooting, and a shake detection means for outputting a shake signal corresponding to the shake of the camera, and due to the shake Correction means for correcting the image blur to be performed, and control means for determining whether or not the frequency of the shake signal is within a specific frequency region and switching between the operation and non-operation of the correction means based on the determination result. Here, the control means sets the lower limit frequency of the specific frequency region to a value on the high frequency side at the first speed when the shake signal is greater than or equal to a predetermined value for a predetermined time or more during still image shooting. If the shake signal is greater than or equal to a predetermined value for a predetermined time or longer during moving image shooting, the lower limit frequency of the specific frequency region is set to a higher frequency at a second speed that is slower than the first speed. Change to a value .

According to the present invention, since the frequency region in which the image shake correction operation is performed is changed between the moving image shooting and the still image shooting, the optimum image shake correction operation can be performed respectively during the moving image shooting and the still image shooting. it can. Also, when the shake signal is greater than or equal to a predetermined value for a predetermined time or longer, panning or tilting that should not be subjected to image blur correction is performed by increasing the lower limit frequency of a specific frequency region than otherwise. Thus, it is possible to reliably prevent the image blur correction operation from being performed when an intentional large shake due to, for example, occurs. Furthermore, by making the second speed slower than the first speed, it is possible to prevent the motion of an image taken at the time of moving image shooting from being accelerated and the moving image from appearing unnatural. Moreover, during still image shooting, unlike moving image shooting, the panning operation may be quickly performed, and the frequency characteristic that does not respond to the quick operation can be changed directly.

Here, moving image shooting, while also capturing slow movement of the subject, since the time of still image shooting is rarely to shoot such movement, the lower limit frequency of a specific frequency range corresponding to the moving picture imaging, still You may make it make it lower than the minimum frequency of the specific frequency area | region corresponding to image photography.

In addition, when shooting still images, relatively high-frequency vibrations occur due to camera shutter button operations, shutter operations, etc., while such high-frequency vibrations are unlikely to occur during movie shooting. The upper limit frequency of a specific frequency region corresponding to still image shooting may be set higher than the upper limit frequency of a specific frequency region corresponding to moving image shooting.

  In addition, the lower limit frequency of the predetermined frequency region that is increased when the signal from the shake detection unit is equal to or greater than the predetermined value for a predetermined time or more is set to be the same during moving image shooting and still image shooting. It may be. For example, because the shake during panning depends on the movement of the subject, the lower limit frequency for moving images and still images is made the same, so the capacity of the storage means of the control circuit (lens controller) can be saved. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a main configuration of a camera system that is Embodiment 1 of the present invention. The left side in the figure shows an interchangeable lens (lens device) that is a camera accessory, and the right side shows a camera.

  Reference numeral 1 denotes an interchangeable lens, which includes three lens units 2, 3, and 4 that constitute a photographing optical system. The lens unit 2 moves in the optical axis direction and performs zooming. The lens unit 3 moves in a plane orthogonal to the optical axis to correct image blur. The lens unit 4 moves in the optical axis direction. Thus, the focus lens unit performs focus adjustment.

  A diaphragm 5 is opened and closed by a diaphragm motor 7 through a transmission mechanism (not shown). A lens controller 20 such as a CPU or MPU that controls various operations in the interchangeable lens 1 controls the open / close state of the diaphragm 5 via the diaphragm drive circuit 8 based on the output of the diaphragm position detector 6.

The correction lens position detectors 10 and 11 detect the position of the correction lens 3 in the pitch axis direction and the yaw axis direction orthogonal to each other in the optical axis orthogonal plane. For example, arranged so as to move the LED floodlight with correcting lens unit 3, by detecting the amount of movement of the LED floodlight with PSD for receiving, detecting the position of the correction lens unit 3, the lens controller 20 To tell.

  Based on outputs from the correction lens position detectors 10 and 11, the lens controller 20 energizes the pitch motor 14 and the yaw motor 15 via an IS (Image Stabilizer) drive circuit 16, thereby causing the correction lens unit 3 to move in the pitch axis direction. And drive in the yaw axis direction. The correction lens unit 3 is driven independently in the pitch axis direction and the yaw axis direction.

  Reference numeral 9 denotes a lock detector, and reference numeral 12 denotes a lock mechanism for fixing the correction lens unit 3 at a predetermined position (for example, a position where the optical axis of the correction lens unit 3 coincides with the optical axis of the photographing optical system). Reference numeral 13 denotes a lock mechanism drive circuit that causes the lock mechanism 12 to perform a lock operation and a lock release operation. When the shake correction operation is not performed, such as when the camera is turned off, the lens controller 20 locks the fixing mechanism 12 via the lock mechanism driving circuit 13 and locks and holds the correction lens unit 3 at a predetermined position.

  A focus lens position detector 17 includes a pulse plate (not shown) that rotates in conjunction with the rotation of the focus motor 18 and a photo interrupter. The lens controller 20 outputs a signal corresponding to the rotation of the focus motor 18. To enter. The focus motor 18 is driven by a focus drive circuit 19 that has received a drive signal from the lens controller 20, whereby the focus lens unit 4 moves.

  Reference numeral 21 denotes a focus lens zone detector. The focus brush is configured so that the conductive brush moves on the pattern electrode arranged on the flat surface or curved surface of the fixed portion of the interchangeable lens 1 according to the movement of the focus lens unit 4. A signal corresponding to the position of the lens unit 4 is output and input to the lens controller 20.

  Reference numeral 22 denotes a zoom lens position detector, which has a configuration in which the conductive brush moves on the pattern electrode arranged on the flat surface or curved surface of the fixed portion of the interchangeable lens 1 according to the movement of the zoom lens unit 2. A signal corresponding to the position of the lens unit 2 is output and input to the lens controller 20. The zoom lens unit 2 is driven by a zoom motor (not shown), and the zoom motor is driven by a zoom drive circuit (not shown) that receives a drive signal from the lens controller 20.

  The lens controller 20 communicates with a camera controller 31 such as a CPU or MPU that performs various controls of the camera side and the entire camera system via the lens communication interface 23 and the camera communication interface 47. The lens controller 20 controls various operations on the lens side based on information and commands obtained through communication with the camera controller 31. As a communication method, it is possible to employ electrical communication via contacts, communication using light using an LED and a phototransistor, communication using magnetic coupling between coils, or wireless communication using radio waves. it can.

  The lens power supply interface 24 receives power supply from the camera side via the camera power supply interface 48. As a power supply method, a method using electrical connection via a contact or a method using magnetic coupling between coils can be employed.

  The ROM 20a provided in the lens controller 20 includes ID data indicating the product type and model number of the interchangeable lens 1, IS optical data for image blur correction, AE optical data for automatic exposure control, and auto focus. It stores optical data for image processing including optical data for AF for adjustment and spectral transmittance data. When the optical data changes depending on the position of the focus lens unit 4 and the position of the zoom lens unit 2, the lens controller 20 communicates the optical data to the camera controller 31 according to the output of the focus lens zone position detector 21. .

  Reference numeral 25 denotes a camera capable of at least one of still image shooting and moving image shooting. As described above, the camera controller 31 controls various operations in the camera 25 and also controls various operations in the lens via the lens controller 20 through the communication described above.

  The ROM 31a in the camera controller 31 corrects optical data of various interchangeable lenses that have already been manufactured and can be attached to the camera 25, and the sensitivity of each pixel of the image sensor 28 measured at the time of designing or manufacturing the camera 25. Data is stored.

  A battery 30 serves as a power source for the camera 25 and the interchangeable lens 1.

  Reference numeral 29 denotes a stabilizing power source, which charges the battery 30 with a current supplied from the external input terminal 32, or stabilizes the voltage of the battery 30 to a predetermined level voltage.

  Reference numeral 46 denotes a switch control circuit, which informs the camera controller 31 of the state of a switch to be described later.

  The switch control circuit 46 includes a metering / focus detection start switch (S1) 49, a release switch (S2) 50, a power switch 51, a moving image / still image switching switch 52, various shooting modes (sport mode, portrait mode, First shooting mode setting switch 53 for setting landscape shooting mode, close-up mode, night scene shooting mode, program AE, shutter priority AE, aperture priority AE, manual exposure, depth priority AE, etc., various IS modes (during shooting) Suitable for IS mode for shooting only when performing image blur correction operation, Always IS mode for performing constant image blur correction operation, IS mode for tripods for performing image blur correction operation suitable for installation on a tripod, and panning operation Panning IS mode for performing image blur correction operation, etc.) Chi 54 is connected.

  Further, the switch control circuit 46 has various AF modes (one-shot AF mode for storing images after focusing, servo AF mode for keeping the focus position on the moving subject, focus position according to the subject movement after focusing) A second shooting mode switch 55 for setting a shooting mode such as a self-timer shooting, remote control shooting, single shooting, continuous shooting, time priority continuous shooting, AF priority continuous shooting, etc. is also connected. ing.

  Reference numeral 26 denotes an optical low-pass filter for preventing aliasing in the image sensor.

  Reference numeral 27 denotes a filter detector that detects the mounting state of the optical low-pass filter 26. The camera controller 31 displays the presence or absence of the optical low-pass filter 26 detected through the filter detector 27 on a display panel 45 including an LCD also serving as an electronic viewfinder, a self-luminous element, and the like.

  The camera controller 31 may change an image processing method to be described later depending on the setting of each switch detected by the switch control circuit 46 and the presence or absence of the optical low-pass filter 28.

  Reference numeral 28 denotes an image pickup device made up of a photoelectric conversion device made up of a CCD, a CMOS sensor or the like. The image sensor 28 receives a subject image formed by the photographing optical system and photoelectrically converts it. By using the output signal from the image sensor 28, the subject image data is recorded, or as disclosed in Japanese Patent Laid-Open No. 2001-83407, the detection of the focus state and the amount of received light of the photographing optical system by the phase difference detection method. Detection (photometry) is possible.

  Furthermore, it is also possible to obtain a signal (image blur signal) indicating the frequency and amount of image blur caused by the shake of the camera system using the output signal from the image sensor 28. That is, the image sensor 28 can be used as a shake detection sensor. Also in this embodiment, an image blur signal is obtained using an output signal from the image sensor 28 and transmitted to the lens controller 20.

  Reference numeral 33 denotes a driver circuit that performs horizontal driving and vertical driving of each pixel of the image sensor 28. The image sensor 28 is driven by an output from the driver circuit 33 to generate and output an image signal.

  A shutter 59 controls the exposure amount to the image sensor 28.

  A CDS / AGC circuit 34 removes noise from the output signal of the image sensor 28 in the CDS circuit section, and adjusts the amplification degree of the output signal in the AGC circuit section.

  Reference numeral 35 denotes a timing generator (TG), which is controlled by the camera controller 31 and determines the entire drive timing. Since the image processing needs to execute a predetermined operation in a short time, not only the camera controller 31 but also a short time is managed by the timing generator 35.

  The CDS / AGC circuit 34 is similarly controlled according to the outputs from the camera controller 31 and the timing generator 35.

  An AD conversion circuit 36 AD-converts the output of the CDS / AGC circuit 34 in accordance with outputs from the camera controller 31 and the timing generator 35 and outputs digital data of each pixel.

  Reference numeral 37 denotes a frame memory which stores the output of the AD conversion circuit 36. Further, in the case of still image continuous shooting or the like, all pixel data is temporarily stored in the frame memory 37. In the case of moving image shooting, some pixel data is temporarily stored in the frame memory 37.

A camera DSP 38 generates RGB color signals from the output of the AD conversion circuit 36 or the pixel data stored in the frame memory 37 in accordance with outputs from the camera controller 31 and the timing generator 35. At this time, image processing is performed using the image processing data captured from the interchangeable lens 1 by communication.

  A video memory 39 stores image data suitable for display on the display panel 45. When the switch connected to the switch control circuit 46 is operated, the image data created by the camera DSP 38 is stored by the output from the camera controller 31 and the timing generator 35 and displayed on the display panel 45.

  The display panel 45 is driven by the display driving unit 40 together with the display light source 44.

  Reference numeral 41 denotes a work memory which stores an output obtained by performing image processing by the camera DSP 38.

  A compression / decompression unit 42 compresses and decompresses data based on a predetermined compression format in accordance with outputs from the camera controller 31 and the timing generator 35.

  A nonvolatile memory 43 stores the data compressed by the compression / decompression unit 42. For example, a non-volatile memory such as a semiconductor memory such as a flash memory or a magnetic memory using a hard disk or a magnetic tape is used.

  When observing the compressed image data that has been taken and stored in the nonvolatile memory 43, the compression / expansion unit 42 decompresses the compressed image data into pixel data suitable for display on the display panel 45, and decompresses the compressed image data into the video memory 39. To store. The display driving unit 40 drives the display panel 45 with the pixel data stored in the video memory 39 to display a captured image.

  The captured image is stored as data from the work memory 41 to the nonvolatile memory 43 and displayed on the display panel 45 immediately after shooting.

  An audio recording circuit 56 converts audio obtained through a microphone (not shown) at the time of moving image shooting and still image shooting into digital data and records it in the nonvolatile memory 43.

  Next, an example of communication between the camera and the lens will be described. The following command or information is transmitted from the camera controller 31 to the lens controller 20, and the lens controller 20 transmits data corresponding to the received command to the camera controller 31 or performs operation control corresponding to the command or information. Or

・ Receiving request command for lens specific data including lens type, product version, function data ・ Receiving request command for IS optical data such as image blur correction sensitivity of image taking optical system, error correction amount of image blur correction, etc.・ Reception request command for AF optical data such as focal length, AF sensitivity, AF error correction amount of photographing optical system ・ Aperture data such as open f-number, minimum aperture value, number of apertures and optical data for AE of photographing optical system -Receiving request command for the correction lens unit 3 Lock command, unlocking command -Image shake signal (information indicating the frequency and amount of shake)
-Defocus amount setting command-Aperture 5 driving direction and driving amount setting command-Movie / still image shooting information indicating whether moving image shooting or still image shooting-IS mode setting information, etc.

  Next, the image blur correction operation will be described. First, the camera controller 31 detects a movement of a subject in an image by obtaining a plurality of image outputs during exposure from the image sensor 28 or obtaining a plurality of image outputs via the camera DSP 38. Using the detection result, a driving command for the correction lens unit 3 is transmitted to the lens controller 20 so that the shake of the image formed on the image sensor 28 is reduced.

  The lens controller 20 drives the pitch motor 14 and the yaw motor 15 via the IS drive circuit 16 based on the received drive command, IS optical data, and moving image / still image shooting information, and drives the correction lens unit 3. Thereby, the shake of the image formed on the image sensor 28 is suppressed.

  Next, the focusing operation will be described. First, the camera controller 31 obtains AF optical data related to focus in the photographing optical system by communication from the lens 1 side. The camera controller 31 calculates the defocus amount based on the AF optical data and the focus detection result obtained by the phase difference detection method of the image sensor 28. Then, this calculation result (defocus amount) is communicated to the lens controller 20.

  The lens controller 20 calculates the drive amount and drive speed of the focus lens unit 4 based on the received defocus amount and AF optical data. At this time, moving image / still image shooting information is received from the camera controller 31, and the drive speed of the focus lens unit 4 is changed according to whether the movie shooting or still image shooting is performed. Specifically, when the drive amount of the focus lens unit 4 is the same, the drive speed during still image shooting is made faster than during moving image shooting.

  Then, the lens controller 20 drives the focus motor 18 via the focus drive circuit 19 according to the calculation result. As the focus motor 18 rotates, the focus lens unit 4 moves. In this way, a focused state is obtained.

  Next, the aperture control operation will be described. The camera controller 31 obtains AE optical data related to the brightness of the photographing optical system and the aperture 5 through communication with the lens controller 20. The camera controller 31 calculates the aperture diameter of the diaphragm 5 based on the AE optical data and the received light amount output of the image sensor 28 and communicates with the lens controller 20.

  The lens controller 20 drives the diaphragm motor 7 via the diaphragm drive circuit 8 and drives the diaphragm 5 so that the aperture diameter is as set by the camera controller 31.

  Next, the operation of the camera 25 (camera controller 31) of this embodiment will be described along the flowchart of the main routine of the camera shown in FIG.

  When started in step S100, the camera controller 31 confirms that the interchangeable lens 1 is attached to the camera 25 by communicating with the lens controller 20 via the in-camera communication interface 47 and the in-lens communication interface 23 in step S101. . When the attachment is confirmed, the process proceeds to step S102, and it is determined whether the image to be recorded is a moving image or a still image by setting the moving image / still image switching switch 52, the first shooting mode switch 53, or the second shooting mode switch 55. To do.

  In the case of moving image shooting, the process proceeds to step S103, and information indicating moving image shooting is transmitted to the lens controller 20. In the case of still image shooting, the process proceeds to step S104, and information indicating still image shooting is transmitted to the lens controller 20.

  In step S105, the camera controller 31 receives lens information such as lens type information, lens function presence / absence information, image processing data, IS optical data, AF optical data, and AE optical data from the lens controller 20. Receive. Hereinafter, the description will be continued on the assumption that the above-described IS mode for photographing is set.

  Next, in step S106, the camera controller 31 detects whether or not the switch S1 (49) is turned on. If it is turned on, the process proceeds to step S107, and image blur correction is performed. If it is not turned ON, the process returns to step S101.

  Next, in step S107, the camera controller 31 transmits a drive command for the correction lens unit 3 to the lens controller 20 so as to reduce the shake of the image formed on the image sensor 28, and execute the image shake correction operation. . On the interchangeable lens 1 side, as described later, according to the IS mode, an image blur correction operation is performed while the switch S1 (49) is being pressed (always IS mode) or the switch S2 (50) is pressed. The image blur correction operation is executed only during shooting (IS mode during shooting).

  When transmitting a drive command for the correction lens unit 3, a lock release command for the correction lens unit 3 is also transmitted to the lens controller 20. Receiving this, the lens controller 20 detects whether or not the lock mechanism 12 is in the locked state through the lock detector 9, and if the lock mechanism is in the locked state, releases the lock via the lock mechanism driving circuit 13.

  Next, in step S108, the camera controller 31 performs a photometric operation according to the AE optical data and the received light amount output of the image sensor 28.

  Subsequently, in step S109, the camera controller 31 calculates the defocus amount based on the AF optical data and the focus detection result in the phase difference detection method based on the output from the image sensor 28. Then, this calculation result (defocus amount) is communicated to the lens controller 20. The lens controller 20 calculates the drive amount and drive speed of the focus lens unit 4 based on the defocus amount, AF optical data, and moving image / still image shooting information. Based on the calculation result, the focus motor 18 is driven via the focus drive circuit 19. As the focus motor 18 rotates, the focus lens unit 4 moves to obtain in-focus.

  Next, in step S110, the camera controller 31 detects whether or not the switch S2 (50) is turned on. When the switch 50 is ON, the process proceeds to step S111.

  In step 111, the aperture setting value calculated in accordance with the photometric result in step S108 is communicated to the lens controller 20, and the aperture 5 is driven to the setting value.

  Next, in step S112, the camera controller 31 accumulates images to be recorded using the output from the image sensor 28. In step S113, image processing is performed using the image processing data obtained from the lens controller 20 through communication. The image data is recorded in the nonvolatile memory 43 as described above.

  In step S114, the camera controller 31 determines whether or not there is an unrecorded capacity of the nonvolatile memory 43. If there is an unrecorded capacity, the process returns to step S101. If no more, go to step S115.

  In step S115, it is displayed on the display panel 45 that there is no unrecorded capacity in the nonvolatile memory 43, and the main flow is terminated in step S116.

  Next, the operation of the lens controller 20 that receives commands and information from the camera controller 31 will be described using the flowchart of FIG.

  When receiving a command or information from the camera controller 31 through communication, the lens controller 20 starts operation from step S201, and analyzes the command or information from the camera controller 31 in step S202 and subsequent steps.

  First, in step S202, it is determined whether the command or information from the camera controller 31 is transmitted in step S103 or transmitted in step S104, that is, whether it is moving image shooting / still image shooting information. When these are received, the process proceeds to step S203, and the moving image data or the still image data is transmitted to the camera controller 31 according to the received information, so that the lens attached to the camera controller 31 is compatible with the still image or the moving image. Recognize something. After the operation of step S203 is completed, the process returns to step S202.

  If it is determined in step S202 that the information is not moving image shooting / still image shooting information, the process proceeds to step S204. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is a command for requesting reception of optical data for image processing. If so, the process proceeds to step S205, and the optical data for image processing is sent to the camera controller 31. Send. After the operation of step S205 is completed, the process returns to step S202.

  If it is determined in step S204 that the command is not a request for receiving image processing optical data, the process proceeds to step S206. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is an IS optical data reception request command, and if so, the process proceeds to step S207 to send the IS optical data to the camera controller 31. Send. After the operation of step S207 is completed, the process returns to step S202.

  If it is determined in step S206 that the command is not a request for receiving optical data for IS, the process proceeds to step S208. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is an AF optical data reception request command, and if so, the process proceeds to step S209 to transmit the AF optical data to the camera controller 31. . After the operation of step S209 is completed, the process returns to step S202.

  If it is determined in step S208 that the command is not an AF optical data request command, the process proceeds to step S210. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is an AE optical data reception request command, and if so, the process proceeds to step S211 to transmit the AE optical data to the camera controller 31. . After the operation of step S211 is completed, the process returns to step S202.

  If it is determined in step S210 that the command is not an AE optical data request command, the process proceeds to step S212. Here, it is determined whether or not the command from the camera controller 31 is a lock mechanism release command and an image shake correction drive command. If so, the process proceeds to step S213. In step S213, if the information received in step S202 is information indicating moving image shooting, the process proceeds to step S214.

  In step S214, the correction lens unit 3 for moving image shooting is driven (blur correction operation) based on the drive command for image blur correction transmitted from the camera controller 31 and the optical data for IS. Here, in the case of moving image shooting, a quieter and smoother shake correction operation is required compared to still image shooting. Further, at the time of panning, the shake correction operation is temporarily interrupted and the shake correction operation is started again after panning. However, the transition must be smooth (this will be described later). In consideration of these, at the time of moving image shooting, lock / unlock of the lock mechanism 12 and drive control of the correction lens unit 3 are executed with particular emphasis on the low frequency characteristics of image shake correction.

  In step S213, if the information received in step S202 is information indicating still image shooting, the process proceeds to step S215. In step S215, the information about the IS mode set by the IS mode setting switch 54 is received from the camera controller 31, and it is determined whether the photographing IS mode or the constant IS mode. If it is in the shooting IS mode, the process proceeds to step S216. If it is always in the IS mode, the process proceeds to step S218.

  In step S216, it is determined from the information transmitted from the camera controller 31 whether or not the switch S2 (50) is turned on. If it is ON, the process proceeds to step 217. If it is not ON, this determination is repeated.

  In steps S217 and 218, the correction lens unit 3 for still image shooting is driven (blur correction operation) based on the drive command for image blur correction and the optical data for IS transmitted from the camera controller 31. Here, in the case of still image shooting, it is necessary that the shake correction accuracy be higher than that during moving image shooting. Further, at the time of panning, the shake correction operation is temporarily interrupted and the shake correction operation is started again after panning. However, it is also necessary that the transition is quick (this will be described later). In consideration of these, at the time of still image shooting, lock / unlock of the lock mechanism 12 and drive control of the correction lens unit 3 are executed with particular emphasis on the high and low frequency characteristics of image blur correction.

  In step S217, the control is performed after the switch S2 (50) is turned on. In step S218, the switch S1 (49) is turned on (by receiving an image blur correction drive command from the camera controller 31). After that, the above control is performed.

  After completing the operations in steps S214, 217, and 218, the process returns to step S202.

  If it is determined in step S212 that the command is not an image blur correction drive command, the process proceeds to step S219. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is a defocus amount setting command, and if so, the process proceeds to step S220.

  In step S220, the drive amount and drive speed of the focus lens unit 4 are calculated based on the received defocus amount, AF optical data, and moving image / still image shooting information. Then, the focus motor 18 is driven via the focus drive circuit 19 according to the calculation result, and the focus lens unit 4 is driven toward the focus. After the operation of step S220 is completed, the process returns to step S202.

  If it is determined in step S219 that the instruction is not a defocus amount setting command, the process proceeds to step S221. Here, the lens controller 20 determines whether or not the command from the camera controller 31 is an aperture drive command, and if so, the process proceeds to step S222 to drive the aperture 5. After the operation of step S222 is completed, the process returns to step S202.

  If it is determined in step S221 that the command is not an aperture drive command, the process proceeds to step S223. Here, the lens controller 20 transmits the optical information to the camera controller 31 when the command from the camera controller 31 is another command, for example, a command for receiving optical information other than those described above. Then, the process returns to step S202.

  Next, an image blur correction operation in the lens controller 20 using an image blur correction drive command (image blur signal) from the camera controller 31 will be described in more detail with reference to FIGS. FIGS. 4A and 4B show frequency characteristics of image blur correction in the lens controller 20. The vertical axis represents the amplification degree of the image blur signal, and the horizontal axis represents the frequency of the image blur signal.

  FIG. 4A shows frequency characteristics during moving image shooting. A solid line indicates a frequency characteristic during normal operation, and this frequency characteristic is characterized by a high-pass filter having a cutoff frequency fhpfm1 and a low-pass filter having a cutoff frequency flpfm.

  The dotted line indicates the frequency characteristics during panning, and is characterized by a high-pass filter having a cutoff frequency fhpfm2 and a low-pass filter having a cutoff frequency flpfm.

  The lens controller 20 determines that panning is in progress when the value of the image blur signal exceeds a predetermined value for a predetermined time or longer, and changes the frequency characteristic from that during normal operation to that during panning.

  FIG. 4B shows frequency characteristics at the time of still image shooting. A solid line indicates a frequency characteristic during normal operation, and this frequency characteristic is characterized by a high-pass filter having a cutoff frequency fhpfs1 and a low-pass filter having a cutoff frequency flpfs.

  A dotted line indicates a frequency characteristic during panning, and is characterized by a high-pass filter having a cutoff frequency fhpfs2 and a low-pass filter having a cutoff frequency flpfs.

  The lens controller 20 determines that panning is in progress when the value of the image blur signal exceeds a predetermined value for a predetermined time or longer, and changes the frequency characteristic from that during normal operation to that during panning.

Here, the relationship between the frequency characteristics on the low frequency side during movie shooting and still image shooting is
fhpfm1 <fhpfs1
It is like this.

  At the time of moving image shooting, if there is a slow movement in the captured image, it is recorded as it is, so the low frequency characteristics are improved so that the image blur correction operation is performed also in such a case. In addition, during still image shooting, slow movements during image shooting are not recorded except in the case of long exposure, so that low frequency characteristics are better during moving image shooting than during still image shooting. That is, the image blur correction operation is performed in response to a lower shake frequency during moving image shooting.

  Note that if the low-frequency characteristics are the same for movie shooting and still image shooting, the image shake correction operation will be performed until it is not necessary for still image shooting, and wasteful power will be consumed. It is not preferable.

In addition, the relationship between the frequency characteristics during panning during movie shooting and still image shooting is as follows:
fhpfm2 = fhpfs2
It is like this.

  This is because during panning, the same characteristics may be used during moving image shooting and still image shooting. However, even in this case, fhpfm2 <fhpfs2.

The relationship between the frequency characteristics on the high frequency side during movie shooting and still image shooting is
flpfm <flpfs
It is like this.

  When shooting a movie, there is little high-frequency shake, but when shooting a still image, there is a high possibility that camera shake such as an operation of pressing the shutter button (switch S1) by the user or the operation of the shutter 59 will occur. Better high-frequency characteristics when shooting still images than when shooting. That is, the image blur correction operation is performed in response to a higher shake frequency during still image shooting.

  Next, a difference between moving image shooting and still image shooting in changing frequency characteristics from normal shooting to panning will be described.

  In moving image shooting, if the frequency characteristic at the time of normal shooting is changed quickly to the frequency characteristic at the time of panning shooting, the movement of the shot image becomes faster and looks unnatural. The frequency characteristics are changed at a slow speed of about 100 ms. On the other hand, when shooting a still image, it may shift to a panning operation quickly unlike when shooting a movie, and it is better to change the frequency characteristic directly so that it does not respond to the quick operation. For example, a fast speed of several mS to about 10 mS. Thus, the frequency characteristic during normal shooting is changed to the frequency characteristic during panning.

  The relationship of the change speed from the above-described frequency characteristic at the time of normal photographing to the frequency characteristic at the time of panning is the same in the tilting.

  FIG. 5A is a diagram for explaining a low-pass filter arithmetic circuit provided in the lens controller 20.

  In this figure, 60 is an input terminal for a signal obtained by DA-converting an image blur signal from the camera controller 31, 61 is a resistance element (resistance value R1) using a PSD element whose resistance value varies depending on the light quantity of the LED 67, and 62 is a capacitor ( Capacitors C1), 63 are operational amplifiers that constitute a low-pass filter by the resistor element R1 and the capacitor C1, 64 is an output terminal, 65 is an input terminal for a control signal of the DA converter 66, and 67 is an LED that changes the amount of light by the output of the DAC. , 68 are input terminals for inputting a reference signal to the positive input terminal of the OP amplifier 63.

The cutoff frequency fclpf of the low-pass filter in this configuration is
fclpf = 1 / (2 · π · R1 · C1)
By changing the resistance value R1 of the resistance element according to the control input value of the input terminal 65, the cut-off frequency can be set to the above flpfm or flpfs.

  FIG. 5B illustrates a high-pass filter arithmetic circuit provided in the lens controller 20.

  70 is an input terminal for a signal obtained by DA-converting the image blur signal from the camera controller 31, 71 is a resistance element (resistance value R2) using a PSD element whose resistance value varies depending on the light quantity of the LED 77, 72 is a capacitor (capacitance C2), 73 is an OP amplifier that constitutes a high-pass filter by the resistor element R2 and the capacitor C2, 74 is an output terminal, 75 is an input terminal for a control signal of the DA converter 76, 77 is an LED whose light amount is changed by the output of the DAC, and 77 is OP This is an input terminal for inputting a reference signal to the positive input terminal of the amplifier 73.

The cutoff frequency fchpf of the high-pass filter in this configuration is
fchpf = 1 / (2 · π · R2 · C2)
By changing the resistance value R2 of the resistance element according to the control input value of the input terminal 75, the cutoff frequency can be set to the above fhpfm1, fhpfm2, fhpfs1, and fhpfs2.

  FIG. 6 shows a timing chart of the shake correction operation in the shooting IS mode and the constant IS mode.

  FIG. 6A shows the state of the switch S1 (49). Here, an example is shown in which the switch S1 (49) is turned on at times t0 to t8.

  FIG. 6B shows the state of the switch S2 (50). Here, an example is shown in which the switch S2 (50) is turned on at times t2 to t7.

  FIG. 6C shows the shooting / non-shooting state of the camera, H indicates shooting (image recording), and L indicates the non-shooting state. Here, shooting is in progress from time t4 to t5.

  FIG. 6D shows the state of the image blur correction (IS) operation performed in step S217 of FIG. 3, wherein ON indicates that the operation is in progress and OFF indicates that the operation is not performed. Here, driving is performed at times t3 to t6.

  FIG. 6E shows the state of the image blur correction (IS) operation performed in step S218 of FIG. 3, where ON indicates that the operation is in progress and OFF indicates that the operation is not performed. Here, driving is performed at times t1 to t9.

  When the shake correction operation in step S217 is executed, the image shake correction operation is started at time t3 immediately after the switch S2 (50) is turned on at time t2 and immediately before time t4 when shooting is started, and at time t5. Since the image blur correction operation is performed only until time t6 immediately after the shooting is finished, power consumption can be suppressed while securing the image blur correction effect at the time of shooting.

  On the other hand, when the shake correction operation in step S218 is executed, the image shake correction operation is started at time t1 immediately after the switch S1 (49) is turned on at time t0, and shooting is finished at time t5, and then time t9 (time Since the image blur correction operation is continued until t6), it is possible to perform shooting at a desired timing while confirming the image blur correction effect on the display panel 45.

  FIG. 7 shows a camera system that is Embodiment 2 of the present invention. In this embodiment, the interchangeable lens 1 is the same as that described in the first embodiment. On the other hand, the camera 25 'is dedicated to moving image shooting, and does not have the moving image / still image changeover switch 52 and the shutter 59 provided in the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals.

  FIG. 8 shows an operation flowchart of the camera (camera controller 31) of the present embodiment. Steps S102 and S104 described in the first embodiment (FIG. 2) are deleted, and step S303 is provided instead of step S103.

  In step S <b> 303, the camera controller 31 transmits information indicating moving image shooting to the lens controller 20. The lens controller 20 performs a moving image blur correction operation according to the flowchart shown in FIG. 3 (step S214).

  As described above, when the interchangeable lens 1 is connected to the camera 25 'dedicated to moving image shooting, the image blur correction operation suitable for the moving image is performed.

  FIG. 9 shows an operation flowchart of the camera (camera controller) in the camera system that is Embodiment 3 of the present invention. In this embodiment, although not shown, the interchangeable lens 1 is the same as that described in the first embodiment. On the other hand, the camera is dedicated to still image shooting, and does not have the moving image / still image changeover switch 52 provided in the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and will be described below.

  In this embodiment, step S102 and step S104 described in the first embodiment (FIG. 2) are deleted, and step S403 is provided instead of step S103.

  In step S <b> 403, the camera controller 31 transmits information indicating still image shooting to the lens controller 20. The lens controller 20 performs an image blur correction operation for a still image according to the flowchart shown in FIG. 3 (steps S215 to 218).

  As described above, the interchangeable lens 1 performs an image blur correction operation suitable for a still image when connected to a camera dedicated to still image shooting.

  In each of the above-described embodiments, the case where the image pickup signal provided in the camera is used as a shake detection sensor to obtain an image shake signal has been described. However, an acceleration sensor, a gyro sensor, or the like is used as a shake detection sensor. Alternatively, an image blur signal may be obtained from the output. In this case, the shake detection sensor may be provided on the interchangeable lens side.

  In each of the above embodiments, the case where the correction lens unit 3 is moved in the plane orthogonal to the optical axis to correct the image blur has been described. However, the image blur correction method according to the present invention is not limited to this method, and the correction lens unit. Can be swung around a predetermined point on the optical axis, or a variable apex prism (VAP) can be driven. Furthermore, the present invention can also be applied when performing an electronic shake correction method for moving the cutout range of an image obtained by the image sensor instead of the optical image shake correction.

  Further, in each of the above embodiments, an interchangeable lens type camera system has been described, but the present invention can also be applied to a lens-integrated camera. In this case, the function of the lens controller may be combined with the camera controller.

1 is a block diagram showing a configuration of a camera system that is Embodiment 1 of the present invention. 3 is a flowchart showing processing on the camera side in Embodiment 1. 5 is a flowchart showing processing on the interchangeable lens side in Embodiment 1. (A) is explanatory drawing of the frequency characteristic of image blur correction at the time of the moving image shooting in Example 1, (b) is explanatory drawing of the frequency characteristic of image blur correction at the time of still image shooting. (A) is explanatory drawing of a low-pass filter arithmetic circuit, (b) is explanatory drawing of a high-pass filter arithmetic circuit. 3 is a timing chart for explaining the operation timing of image blur correction in the first embodiment. FIG. 6 is a configuration diagram of a camera system that is Embodiment 2 of the present invention. 9 is a flowchart illustrating processing on the camera side in Embodiment 2. 9 is a flowchart showing processing on the camera side in the camera system that is Embodiment 3 of the present invention.

Explanation of symbols

1 Interchangeable Lens 20 Lens Controller 25 Camera 28 Image Sensor 31 Camera Controller 34 CDS / AGC Circuit 38 Camera DSP
49 Switch S1
50 Switch S2
52 Movie / Still Image Switch 53 First Shooting Mode Setting Switch 54 IS Mode Switch 55 Second Shooting Mode Setting Switch

Claims (5)

A camera having switching means for switching between video shooting and still image shooting,
A shake detection means for outputting a shake signal corresponding to the shake of the camera;
Correction means for correcting image blur caused by the shake;
Wherein the frequency of the vibration signal to determine whether a particular frequency range, have a control means for switching the operation and non-operation of the correction means based on the determination result,
The control means changes the lower limit frequency of the specific frequency region to a value on the high frequency side at a first speed when the shake signal is a predetermined value or more for a predetermined time or more during still image shooting. If the shake signal is greater than or equal to the predetermined value for the predetermined time or longer during movie shooting, the lower limit frequency of the specific frequency region is increased at a second speed that is slower than the first speed. A camera characterized by changing to a value on the frequency side .   The camera according to claim 1, wherein the control unit lowers a lower limit frequency of the specific frequency region corresponding to moving image shooting to a lower limit frequency of the specific frequency region corresponding to still image shooting. .   The said control means makes the upper limit frequency of the said specific frequency area | region corresponding to still image imaging | photography higher than the upper limit frequency of the said specific frequency area | region corresponding to moving image imaging | photography. Camera. The camera includes a camera body, composed of a detachable lens unit to the camera body, the control means, to any one of claims 1 to 3, characterized in that mounted on the lens device The listed camera. A lens device that can be attached to and detached from a camera having switching means for switching between moving image shooting and still image shooting,
A shake detection means for outputting a shake signal corresponding to the shake of the camera;
Correction means for correcting image blur caused by the shake;
Wherein the frequency of the vibration signal to determine whether a particular frequency range, have a control means for switching the operation and non-operation of the correction means based on the determination result,
The control means changes the lower limit frequency of the specific frequency region to a value on the high frequency side at a first speed when the shake signal is a predetermined value or more for a predetermined time or more during still image shooting. If the shake signal is greater than or equal to the predetermined value for the predetermined time or longer during movie shooting, the lower limit frequency of the specific frequency region is increased at a second speed that is slower than the first speed. A lens apparatus characterized by changing to a value on the frequency side .

Images