JP2006201568A - Camera with camera shake detection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the problem that there are many cases to obtain a picture so-called out of focusing since it is needed to perform an auto-focusing while the camera is in hand shake in a camera in which an auto-focusing is conducted by a plurality of auto-focusing means in order to improve a focusing precision. <P>SOLUTION: In the camera in which focusing precision is being emphasized during a normal imaging time by performing the auto-focusing operations using a plurality of auto-focusing means, only one is used to conduct auto-focusing among the plurality of auto-focusing means so that the auto-focusing operations prior to photographing and a lens focusing operation are quickly completed to avoid the situation in which a blurred picture is taken. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is equipped with a plurality of distance measuring means and a camera shake detecting means for detecting camera shake of a camera by a photographer, and the distance measuring means to be used is used singly or in accordance with the output from the camera shake detecting means. The present invention relates to a camera that selectively switches between.

  Conventionally, as described in Japanese Patent Application Laid-Open No. 2003-029132, this type of camera is one of a plurality of ranging areas formed in an imaging area corresponding to the shake direction and the shake amount of the camera body. One for selecting one ranging area is disclosed.

Japanese Patent Application Laid-Open No. 10-293245 and Japanese Patent Application Laid-Open No. 10-229516 disclose a camera that switches between a plurality of distance measuring means. These cameras switch between ambient light distance measurement and contrast distance measurement depending on the situation, and a method for switching which method to use depending on the detected temperature, macro mode, aperture value, and focal length. Is mentioned.
JP 2003-029132 A JP-A-10-293245 JP-A-10-229516

  However, in the above-mentioned conventional Japanese Patent Application Laid-Open No. 2003-029132, the distance measuring point is changed in accordance with the camera shake direction and the camera shake amount, and reference should be made to shortening the distance measurement time and eliminating the out-of-focus photo. The objective is to improve the usability of the camera or to focus on a subject that the photographer wants to focus on without being aware of camera shake.

  Further, when contrast distance measurement and phase difference distance measurement or external light distance measurement disclosed in the above conventional example, Japanese Patent Application Laid-Open Nos. 10-293245 and 10-229516, etc. are compared, contrast distance measurement is an image. In order to find the focal point while scanning, there is a drawback that it usually takes time to focus, the scene is a moving object or a subject that shoots a fast-moving subject continuously, or the photographer himself It is not suitable for cases such as when the camera shakes. On the other hand, in the case of phase difference ranging or ambient light ranging, the focusing accuracy is not as good as the above-mentioned contrast ranging, but the focusing time is short, so even in scenes where time lag is undesirable. There is an advantage that it is possible to respond sufficiently and the distance to the subject can be measured at high speed.

  According to the present invention, in a camera performing a distance measurement operation using a contrast distance measurement unit with an emphasis on focusing accuracy during normal shooting, the plurality of measurement values are detected when a camera shake exceeding a predetermined value is detected. Ranging with the fastest ranging means among the distance means and focusing the lens, the distance measuring operation and the lens focusing operation before shooting exposure are quickly completed, and so-called out-of-focus photos are taken. It aims at avoiding it.

  In the first invention, at least two distance measuring means and a camera shake detecting means for detecting camera shake of the camera are provided, and when the output from the camera shake detecting means exceeds a predetermined value, The focus detection and focusing operations are performed using only one distance measuring means.

  In the second invention, the optical path dividing means for dividing the subject light flux through the photographing optical system into the first light flux and the second light flux, the first photoelectric conversion means for receiving the first light flux, and the second The second photoelectric conversion means for receiving the light flux, the first distance measurement means for measuring the distance by the output from the first photoelectric conversion means, and the distance measurement by the output from the second photoelectric conversion means A second distance measuring means; and a camera shake detecting means for detecting camera shake of the camera, and using the first distance measuring means and the second distance measuring means alone in accordance with an output from the camera shake detecting means. The focusing operation is performed by selectively switching between the use of both.

  In the third invention, the at least two distance measuring means according to claim 1 and the first and second distance measuring means according to claim 2 are active distance measuring means and / or passive distance measuring means. Features.

  According to the first aspect of the present invention, at least two distance measuring means and a camera shake detecting means for detecting camera shake are provided, and when the output from the camera shake detecting means exceeds a predetermined value, at least two distance measuring means are provided. Since focus detection and focusing operations are performed using only one ranging unit, the focusing operation is performed using a plurality of ranging units with emphasis on focusing accuracy during normal shooting. When a camera shake of a predetermined value or more is detected in a certain camera, the distance measurement operation and the lens before photographing are performed by measuring the distance with only one of the plurality of distance measuring means and focusing the lens. It is possible to quickly end the focusing operation and avoid taking a so-called out-of-focus photo.

  According to the second aspect of the present invention, the optical path splitting means for splitting the subject light flux through the photographing optical system into the first light flux and the second light flux, and the first photoelectric conversion means for receiving the first light flux. The second photoelectric conversion means for receiving the second light flux, the first distance measuring means for measuring the distance by the output from the first photoelectric conversion means, and the output from the second photoelectric conversion means A second distance measuring means for measuring a distance; and a camera shake detecting means for detecting camera shake of the camera; and the first distance measuring means and the second distance measuring means according to an output from the camera shake detecting means. For example, when a camera shake of a photographer is detected, only a distance measuring means that takes a short distance is used. By measuring and focusing, the camera shakes while measuring, So-called out-of-focus photos can be prevented from being taken.

  According to the invention described in claim 3, the at least two distance measuring means described in claim 1 and the first and second distance measuring means described in claim 2 are active distance measuring means and / or passive distance measuring means. Therefore, in the normal shooting, both the active distance measurement and the passive distance measurement are performed for accuracy assurance, and when the camera shake of the photographer is detected, the processing speed of the active distance measurement and the passive distance measurement is reduced. It is possible to prevent the camera shake from being taken using the faster one.

  FIG. 1 is a longitudinal sectional view of a camera, which is a layout diagram of main component mechanisms, showing an embodiment of the present invention. FIG. 2 is a schematic diagram of the distance measuring optical system of the present invention. FIG. 3 is a block diagram showing the configuration of the camera according to the embodiment of the present invention. FIG. 4 is a perspective view showing a diaphragm and a secondary imaging lens described later according to the embodiment of the present invention. FIG. 5 is a perspective view showing a distance measuring element according to an embodiment of the present invention. FIG. 6 shows a flowchart at the time of photographing by the camera according to the embodiment of the present invention.

  1 to 5, reference numeral 1 denotes a photographing lens unit. Reference numerals 2, 3, 6, and 7 are photographic lenses, 3 is a zooming lens that moves on the photographic optical axis L1 to change the photographic magnification, and 7 is a focal point that moves on the photographic optical axis L1 to adjust the focus. It is an adjustment lens. Reference numeral 4 denotes a diaphragm that adjusts the amount of photographing light by forming a plurality of diaphragm diameters by changing the amount of overlap by moving a plurality of blades. In this embodiment, the iris diaphragm has a substantially circular shape. Reference numeral 5 denotes an optical element that adjusts the amount of light transmitted through the photographing optical system, and uses an ND filter, a transmissive liquid crystal that controls the light transmittance by changing the drive voltage, and the like. The optical element 5 that adjusts the amount of transmitted light is used to prevent the aperture diameter from becoming smaller than a predetermined value because the diffraction phenomenon causes deterioration of the image as the aperture diameter of the aperture 4 is reduced.

  A distance measuring element 19 includes a plurality of paired line sensors (19a, 19d or 19b, 19c) which are distance measuring means for detecting an image for performing a distance measuring operation. Reference numeral 8 denotes a half mirror that is an optical path dividing unit that divides a photographing optical path, and uses transmitted light for the distance measuring element 19 of the phase difference distance measuring unit and reflected light for the image sensor 11 that is an imaging unit. Reference numeral 9 denotes a shutter mechanism for blocking a light beam from the photographing optical system. An optical low-pass filter (LPF) 10 that prevents moire is often used in combination with an infrared cut filter or a color correction filter. Reference numeral 11 denotes an imaging element such as a CCD which is an imaging means for converting light from the photographing optical path into an electric signal. A field lens 12 is an objective lens that guides an image formed on the primary imaging plane F1 to the distance measuring element 19. A secondary imaging lens 16 is an optical member having a plurality of pairs of lenses for forming an image on the secondary imaging surface F2 of the distance measuring element 19. Reference numeral 15 denotes an aperture for separating the light flux to the distance measuring element 19. F1 is a primary image plane on which the photographing optical system 1 connects images. F2 is a secondary imaging plane obtained by reimaging the aerial image on the primary imaging plane F1 on the distance measuring element 19. Reference numeral 14 denotes an infrared cut filter for removing infrared light harmful to distance measurement. Reference numeral 13 denotes a distance measuring mirror for changing the direction of the distance measuring light beam. In this embodiment, the distance measuring optical system is bent and arranged above the camera. A distance measuring element 19 performs a known phase difference distance measurement for detecting two image shift amounts of subject light that has passed through different pupils.

  The field lens 12, which is an objective lens, the distance measuring mirror 13, the stop 15, the infrared cut filter 14, the secondary imaging lens 16, and the distance measuring element 19 constitute a distance measuring unit 83. Reference numeral 82 denotes a camera embodying the present invention.

  Reference numeral 81 denotes a known flexible wiring board. In this embodiment, the imaging element 11 and the distance measuring element 19 are mounted, and are electrically connected to a system control circuit 50 which is a central processing unit described later. .

  Reference numeral 17 denotes an A / D converter that converts an analog signal output from the image sensor 11 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 11, the A / D converter 17, and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50. .

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 17 or the data from the memory control circuit 22. In the image processing circuit 20, a predetermined calculation process is performed using the captured image data, and the system control circuit 50 controls the exposure control unit 40 and the distance measurement control unit 42 based on the obtained calculation result. Distance measurement processing, automatic exposure processing, and EF (flash pre-emission) processing are performed. Further, the image processing circuit 20 performs predetermined arithmetic processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  A memory control circuit 22 controls the A / D converter 17, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. Data of the A / D converter 17 is written into the image display memory 24 or the image recording memory 30 through the image processing circuit 20, the memory control circuit 22, or directly through the memory control circuit 22. Reference numeral 23 denotes a contrast calculation unit, which is normally included in the image processing circuit 20, but will be described separately for convenience of explanation. The contrast calculation unit 23 detects a change in luminance signal of the image sensor 11 (so-called contrast), and controls the system control circuit 50 so as to drive the focus adjustment lens 7 to a position where the contrast is maximized, that is, in focus. Then, a drive signal is sent to the distance measurement control means 42.

  Reference numeral 24 denotes an image display memory. Reference numeral 26 denotes a D / A converter. Reference numeral 28 denotes an image display unit composed of a TFT LCD or the like, and display image data written in the image display memory 24 is displayed by the image display unit 28 via the D / A converter 26. If image data captured using the image display unit 28 is sequentially displayed, moving image display can be realized. The image display unit 28 is also used for displaying remaining battery power, strobe charging completion, selection screen display when setting the device mode, time / date display, and the like. The display element used in the image display unit 28 is a liquid crystal display panel such as a TFT method.

  Reference numeral 30 denotes an image recording memory for storing captured still images and moving images. The image recording memory 30 has a storage capacity sufficient to store a predetermined number of still images and a moving image for a predetermined time. Thereby, high-speed and large-scale image writing such as continuous shooting and moving image shooting for continuously shooting a plurality of still images can be performed on the image recording memory 30. The image recording memory 30 can also be used as a work area for the system control circuit 50.

  A compression / decompression circuit 32 compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like. The compression / decompression circuit 32 reads an image stored in the image recording memory 30, performs a compression process or an expansion process, and writes the processed data to the image recording memory 30.

  Reference numeral 40 denotes exposure control means for controlling the driving of the shutter mechanism 9, and reference numeral 42 denotes a measurement for controlling the driving of the focus adjusting lens 7 in order to adjust the focus of the taking lens units (the taking lenses 2 to 6 and the focus adjusting lens 7). Distance control means. Reference numeral 46 denotes zoom control means for controlling the driving of the lens for zooming the taking lens unit. 43 is a filter control means. Reference numeral 45 denotes an aperture control means. The brightness of the subject imaged by the image processing circuit 20 is measured (photometry), and a signal is sent to the aperture control means 45 from the result to drive the aperture 4. At this time, in order to prevent diffraction due to the small stop, control is performed so that a bright subject is not stopped smaller than a predetermined stop diameter. Each of the control means 40, 42, 45, 46 uses an actuator such as a stepping motor or a plunger. Further, when the light reducing optical element is an ND filter, the filter control unit 43 uses a stepping motor or a plunger as an actuator for inserting / removing the ND filter into / from the photographing optical path.

  A strobe 48 emits flash light toward the subject to illuminate the subject.

  A system control circuit 50 is a central processing unit (CPU) that controls the operation of the entire camera of the present invention. A memory 52 stores constants, variables, programs, and the like for the operation of the system control circuit 50. Reference numeral 56 denotes an electrically erasable / recordable non-volatile memory such as an EEPROM, which stores custom function settings and messages set by the photographer.

  Reference numerals 60, 62, 64, and 66 denote operation means for inputting various operation instructions of the system control circuit 50, and are configured by a single or a plurality of combinations such as a switch, a dial, and a touch panel. Specifically, reference numeral 60 denotes a power switch, which turns on / off the power of the camera. A zoom switch 62 instructs to change the focal length of the photographing lens. 64 is a release switch. When the first stroke switch is turned on, the start of operations such as AF (autofocus) processing, AE (automatic exposure) processing, AWB (auto white balance) processing is instructed, and when the second stroke switch is turned on. Subsequently, the shutter mechanism 9 is opened / closed, the signal read from the image sensor 11 is exposed to image data in the memory 30 via the A / D converter 17 and the memory control circuit 22, and the image processing circuit 20 and the memory control circuit 22 Instructs the start of a series of release processes such as a development process using computation, a recording process in which image data is read from the image recording memory 30, compressed by the compression / decompression circuit 32, and written to the recording medium 100.

  Reference numeral 70 denotes a power control circuit, which includes a battery detection circuit, a DC-DC converter, a switch circuit for switching a block to be energized, etc., and detects whether or not a battery is installed, the type of battery, and the remaining battery level. The DC-DC converter is controlled based on the result and an instruction from the system control circuit 50, and a necessary voltage is supplied to each unit including the recording medium for a necessary period. 72 and 74 are connectors. A power source 76 is composed of a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a lithium ion battery, an AC adapter, or the like.

  Reference numeral 80 denotes an interface with a recording medium such as a memory card or a hard disk. A connector 82 connects to a recording medium such as a memory card or a hard disk. The interface and connector may be configured using a PCMCIA card, SD card, or other standard. Furthermore, when the interface 104 and the connector 106 are configured using a PCMCIA card, SD card, or other standard, communication such as a LAN card, modem card, USB card, IEEE 1394 card, P1284 card, SCSI card, PHS, etc. By connecting various communication cards such as cards, image data and management information attached to the image data can be transferred to and from other computers and peripheral devices such as printers.

  Reference numeral 100 denotes a recording medium such as a memory card or a hard disk, which includes a recording unit 102 composed of a semiconductor memory, a magnetic disk, or the like, an interface 104 with the apparatus main body side, and a connector 106 for connection with the apparatus main body side connector 82. And is detachably attached to the apparatus main body. The recording medium 100 and the image recording memory 30 can move and copy image files recorded on each other.

  In the above configuration, the optical path of the photographing optical system 1 is divided into the image pickup means and the distance measuring means side by the half mirror 8 which is the optical path dividing means. The light that has passed through the photographing lens unit 1 is guided by the half mirror 8 so that reflected light is directed to the image sensor 11 and transmitted light is guided to the distance measuring element 19 that is the distance measuring means. The photographing optical system 1 is fixed to a lens frame, and the focal length is changed by a known zooming cam.

  The photographing optical system 1, the half mirror 8, the shutter mechanism 9, the image pickup device 11 as an image pickup means, and the distance measuring means 19 are arranged in a fixed cylinder (not shown) in which the photographing optical system 1 does not rotate.

  Each of the images formed on the distance measuring element 19 which is a distance measuring means has two pairs of sensors 19a and 19d and 19b and 19c. The defocus amount is calculated by receiving a shift signal between the two images. Then, the CPU 50, which is a central processing unit, calculates and converts the subject image into the feed amount of the focus adjustment lens 7, and drives the drive means 42 to adjust the focus.

  Reference numeral 200 denotes a camera shake detection unit which grasps the vibration state of the camera body using a known vibration gyroscope or the like and communicates with the CPU 50.

  In the above configuration, the description of the operation at the time of shooting will be described based on the flowchart of FIG. Numbers with # indicate each program step.

  # 1: The camera's power switch 60 is turned on and the camera is ready to shoot. The photographer operates the zoom switch 62 to stop the zoom lens 3 at a desired angle of view.

  # 2: The photographer determines whether or not the first-stage click switch (SW1) of the release switch 64, which is the two-stage switch of the camera, is ON.

  # 3: The light beam that has passed through the photographing lens unit 1 reaches the distance measuring unit 83 and performs a known phase difference distance measurement by the distance measuring element 19.

  # 4: If camera shake is detected by the camera shake detection means 200 or if the camera shake amount deviates from a predetermined shake amount set in advance, the process proceeds to # 6, and if it is less than the predetermined value, the process proceeds to # 5. .

  # 5: A so-called contrast distance measurement (TV distance measurement) is performed in which the contrast calculation unit 23 detects a change in luminance signal of the image sensor 11 (a contrast).

  # 6: A drive signal is sent to the distance measurement control means via the system control unit 50 so as to drive the focus adjustment lens 7 to drive the lens.

  # 7: The photographer determines whether or not the second-stage click switch (SW2) of the release switch 64, which is the two-stage switch of the camera, is ON.

  # 8: Driving of the shutter mechanism 9 is controlled by the exposure control means 40, and the imaging operation is performed by the imaging element 11.

  In this flowchart (FIG. 6), the camera shake is detected only after the phase difference ranging, but the output signal of the camera shake detecting means 200 is always monitored and the camera shake detecting means 200 detects camera shake. If the amount of camera shake is detected or deviates from a predetermined amount of camera shake, the present invention can be implemented even if the sequence of skipping # 3 to # 6 and proceeding to # 6 is advanced. There is no change in the mode.

  With the above-described configuration, in normal shooting where the camera shake of the photographer is equal to or less than a predetermined value, both the phase difference distance measurement and the contrast distance measurement (TV distance measurement) are performed to ensure accuracy. When a camera shake of a predetermined value or more is detected, only the phase difference distance measurement with a high processing speed is used, and the distance measurement operation and the lens focusing operation are quickly terminated, and a so-called out-of-focus photo is taken. Can be avoided.

1 is a longitudinal sectional view of a camera, which is a layout diagram of main component mechanisms representing an embodiment of the present invention. The schematic diagram of the ranging optical system of this invention. The block diagram which shows the structure of the camera of this invention embodiment. The perspective view showing the aperture_diaphragm | restriction and secondary resolution lens which concern on an Example of this invention. The perspective view showing the ranging element which concerns on an Example of this invention. FIG. 6 is a diagram illustrating a fraught chart at the time of photographing by the camera according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting lens unit 3 Zooming lens 4 Aperture 7 Focus adjustment lens 8 Half-mirror (optical path dividing means)
9 Shutter mechanism 10 IR cut filter 11 Image sensor (imaging means)
12 Field lens 15 Aperture 16 Secondary imaging lens 19 Distance measuring element (phase difference distance measuring means)
42 Distance Control Unit 43 Filter Control Unit 45 Aperture Control Unit 50 System Control Circuit 82 Camera 83 Distance Measurement Unit 200 Camera Shake Detection Unit (Camera Shake Detection Unit)
F1 Primary imaging plane F2 Secondary imaging plane

Claims (3)

  At least two distance measuring means and a camera shake detecting means for detecting camera shake of the camera, and when the output from the camera shake detecting means exceeds a predetermined value, only one distance measuring means of at least two distance measuring means A camera capable of detecting camera shake, characterized in that a focus detection and focusing operation are performed using a camera.   Optical path dividing means for dividing the subject light flux through the photographing optical system into a first light flux and a second light flux, a first photoelectric conversion means for receiving the first light flux, and a second for receiving the second light flux. Photoelectric conversion means, first distance measurement means for measuring distance with the output from the first photoelectric conversion means, and second distance measurement means for measuring distance with the output from the second photoelectric conversion means And a camera shake detecting means for detecting camera shake of the camera, and selectively using either the first distance measuring means and the second distance measuring means in accordance with the output from the camera shake detecting means. A camera capable of detecting camera shake, characterized in that a focusing operation is performed by switching to.   The at least two distance measuring means according to claim 1 and the first and second distance measuring means according to claim 2 are active distance measuring means and / or passive distance measuring means. Camera.

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