JP2006189621A - Automatic focusing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic focusing device capable of preventing erroneous measurement caused by subjects the distances of which are different are present in a distance measurement area, by reducing the area of the distance measurement area when an imager is fixed and determined to be stationary. <P>SOLUTION: The device includes: an extracting means by which signals indicating the high frequency component of a subject are extracted from the signals from the light receiving face of an imager, which correspond to one or more distance measurement areas set on a photographic image plane; a focused position detecting means by which a focused position is detected for the output signal of each distance measurement area, extracted by the extracting means; a focused area selecting means by which the distance measurement area to be focused is selected based upon detection information from the focused-position detecting means; and a means for driving a focus lens to the focused position of the distance measurement area selected by the focused-area selecting means. The area of the distance measurement area is reduced, based upon the detection result of a stationary detecting means for detecting that the imager is stationary. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automatic focusing device, and more particularly to an automatic focusing device used for an electronic still camera, a video camera, and the like.

  In an electronic still camera, a video camera, and the like, an automatic focus detection device that performs a focusing operation by processing a high-frequency component of a luminance signal obtained from an image sensor such as a CCD is used. In this automatic focus detection apparatus, the lens position with the highest contrast is detected by integrating the high frequency components of the signals in the distance measurement area set in each screen, and the focal point is obtained.

  In such an integral detection method, if the area of the distance measurement area is too large, there is a problem that erroneous distance measurement is likely to occur when subjects with different object distances exist at the same time. If the area of the distance measurement area is too small, if one or both of the imaging device and the subject move between the focus detection operation and the shooting operation, there is a problem that an unintended portion is focused. For this reason, it is necessary to set a distance measurement area that takes into account the relative positional movement between the imaging device and the subject at the time of shooting.

Further, as another conventional example, for example, Patent Document 1 can be cited.
Japanese Patent Laid-Open No. 11-249001

  The relative positional movement between the imaging device and the subject at the time of shooting described above is not necessary to be taken into account under shooting conditions in which the imaging device is fixed by a fixing member such as a tripod and is considered to be stationary. . Under such shooting conditions, it is necessary to sufficiently reduce the area of the distance measurement area in order to prevent erroneous distance measurement due to the simultaneous existence of subjects with different distances in the distance measurement area. For example, FIG. 1 shows a case where the distance measurement area includes a table in front of the person as shown by a dotted line in the figure, a wall behind the position where the person stands, and the like. In such a photographing state, it is desirable to use a distance measuring area having a smaller area as shown by a solid line in the figure.

  The object of the present invention is to reduce the distance measurement area when the imaging device is fixed and considered to be stationary, and to prevent erroneous distance measurement due to the presence of subjects with different subject distances in the region. An object of the present invention is to provide an automatic focusing device that can be prevented.

  In order to achieve the above-described object, an automatic focusing device according to claim 1 includes a stationary detection unit that detects that the imaging device is stationary, a focus lens that performs focus adjustment of a subject image, and the focus lens. A focus lens driving means for driving; an image sensor for converting an object image formed by the focus lens into an electric signal; and light receiving by the image sensor corresponding to one or a plurality of distance measuring areas set on a photographing screen. An extraction means for extracting a signal indicating a high-frequency component of the object from the surface signal; an in-focus position detection means for detecting an in-focus position with respect to an output signal of each ranging area by the extraction means; and the in-focus position A focus area selection means for selecting a distance measurement area to be focused on the basis of detection information from the detection means, and a focus area of the focus detection area selected by the focus area selection means. And a control means for controlling the focus lens driving means to drive the Kasurenzu, based on the detection result of said still detection means, characterized in that to reduce the area of the distance measuring area.

  In order to achieve the above-mentioned object, the automatic focusing device according to a second aspect is the invention according to the first aspect, wherein the stationary detection means is an installation means on a fixing member such as a tripod provided in the imaging device. It is characterized by operating in conjunction.

  In order to achieve the above object, according to a third aspect of the present invention, the automatic focusing device according to the first aspect is characterized in that the stationary detection means is an angular velocity sensor provided in the imaging apparatus.

  In order to achieve the above-described object, an automatic focusing device according to claim 4 includes a stationary detection unit that detects that the imaging device is stationary, a focus lens that performs focus adjustment of a subject image, and the focus lens. A focus lens driving means for driving; an image sensor for converting an object image formed by the focus lens into an electric signal; and light receiving by the image sensor corresponding to one or a plurality of distance measuring areas set on a photographing screen. An extraction means for extracting a signal indicating a high-frequency component of the object from the surface signal; an in-focus position detection means for detecting an in-focus position with respect to an output signal of each ranging area by the extraction means; and the in-focus position A focus area selection means for selecting a distance measurement area to be focused on the basis of detection information from the detection means, and a focus area of the focus detection area selected by the focus area selection means. Control means for controlling the focus lens driving means to drive the focus lens, and based on the detection result of the stationary detection means, the area of a part of the plurality of distance measuring areas is more It is characterized in that a small portion is used as a ranging area.

  In order to achieve the above-mentioned object, the automatic focusing device according to claim 5 is the invention according to claim 4, wherein the stationary detection means is a means for installing on a fixing member such as a tripod provided in the imaging device. It is characterized by operating in conjunction.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the automatic focusing device of the fourth aspect, the stationary detection means is an angular velocity sensor provided in the imaging apparatus.

  In order to achieve the above-mentioned object, an automatic focusing device according to a seventh aspect includes a stationary detection means for detecting that the imaging device is stationary, a focus lens for adjusting the focus of a subject image, and the focus lens. A focus lens driving means for driving; an image sensor for converting an object image formed by the focus lens into an electric signal; and light receiving by the image sensor corresponding to one or a plurality of distance measuring areas set on a photographing screen. An extraction means for extracting a signal indicating a high-frequency component of the object from the surface signal; an in-focus position detection means for detecting an in-focus position with respect to an output signal of each ranging area by the extraction means; and the in-focus position A focus area selection means for selecting a distance measurement area to be focused on the basis of detection information from the detection means, and a focus area of the focus detection area selected by the focus area selection means. Control means for controlling the focus lens driving means to drive the focus lens, and based on the detection result of the stationary detection means, one or a plurality of smaller total areas provided separately from the ranging area It is characterized in that this area is a ranging area.

  In order to achieve the above-mentioned object, the automatic focusing device according to claim 8 is the invention according to claim 7, wherein the stationary detection means is installed on a fixing member such as a tripod provided in the imaging device. It is characterized by operating in conjunction.

  In order to achieve the above object, according to a ninth aspect of the present invention, in the invention of the seventh aspect, the stationary detection means is an angular velocity sensor provided in the imaging device.

  According to the automatic focusing device of claims 1, 2, 1, and 3, the area of the distance measurement area is reduced in the case of shooting conditions in which the imaging device is fixed and considered to be stationary. Since the size is reduced, it is possible to prevent erroneous distance measurement due to the presence of subjects having different subject distances in the region.

  According to the automatic focusing device of claims 4, 5 and 4, and 6, in the case of an imaging condition in which the imaging device is fixed and considered to be stationary, a plurality of ranging areas are Since the smaller area of some of the distance measurement areas is used as the distance measurement area, erroneous distance measurement due to the presence of subjects having different focal lengths in the area can be prevented.

  According to the automatic focusing device of claims 7, 8 and 7, and 9, the total area provided separately in the case of shooting conditions in which the imaging device is fixed and considered to be stationary Since one or a plurality of areas having a smaller distance than the distance measurement area is used as the distance measurement area, erroneous distance measurement due to the presence of subjects having different object distances in the area can be prevented.

  As described above, according to the automatic focusing device of claim 1, claim 2, claim 1, and claim 3, in the case of shooting conditions where the imaging device is fixed and considered to be stationary, Since the area of the distance measurement area is reduced, it is possible to prevent erroneous distance measurement due to the existence of objects with different object distances in the area.

  According to the automatic focusing device of claims 4, 5 and 4, and 6, in the case of an imaging condition in which the imaging device is fixed and considered to be stationary, a plurality of ranging areas are Since the smaller area of some of the distance measurement areas is used as the distance measurement area, erroneous distance measurement due to the presence of subjects having different focal lengths in the area can be prevented.

  According to the automatic focusing device of claims 7, 8 and 7, and 9, the total area provided separately in the case of shooting conditions in which the imaging device is fixed and considered to be stationary Since one or a plurality of areas having a smaller distance than the distance measurement area is used as the distance measurement area, erroneous distance measurement due to the presence of subjects having different object distances in the area can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing the configuration of the electronic camera to which the first embodiment of the present invention is applied.

  Reference numeral 201 denotes a fixed lens, 202 denotes an aperture and a shutter for controlling the amount of light, 203 denotes a motor for moving the aperture and the shutter, 204 denotes a mechanical system driving circuit that drives the motor 203 to move the aperture and the shutter 202, and 205 denotes an imaging device described later. A focus lens for focusing the lens, 206 a photo interrupter for detecting a reset position of the focus lens 205, 207 a motor for driving the focus lens 205, 208 a focus lens driving circuit for driving the motor 207 to move the focus lens, Reference numeral 209 denotes an image sensor as a light receiving unit or photoelectric conversion unit that converts reflected light from an object into an electric signal, 210 denotes a timing signal generation circuit that generates a timing signal necessary for operating the image sensor 209, and 211 denotes an image sensor. 209 output noise Pre-processing circuit having a CDS circuit to be removed and a non-linear amplifier circuit to be performed before A / D conversion, 212 is an A / D converter, 213 is a buffer memory, 214 is a memory for controlling memory read / write and DRAM refresh operations A controller 215 is a system control CPU for controlling the system such as a shooting sequence, 216 is a display for assisting operation and a display of the camera state, and an operation display unit 217 for displaying a shooting screen and a distance measurement area at the time of shooting. An operation unit for operating the camera from the outside, 218 is an electrically rewritable nonvolatile memory (EEPROM), 219 is an interface with an expansion unit to be described later, and 220 is connected to the electronic camera body to perform various processes and operations. A detachable extension unit 221 for performing an interface for connection with a recording medium to be described later , 222 is a recording medium such as a memory card or hard disk, 223 is a main switch for powering on the system, 224 is a switch for performing a shooting standby operation such as AF or AE (hereinafter referred to as SW1), 225 is A photographing switch (hereinafter referred to as SW2) for photographing after the operation of SW1, 226 is a mode switch for setting a photographing mode, 227 is a flash, 228 is an auxiliary light source as a light projecting means using an LED or the like as a light source, 229 A stationary detection sensor that detects that the camera is stationary and detects whether the camera is stationary in conjunction with the camera being attached to a fixed member such as a tripod.

  Hereinafter, the operation of the first embodiment of the automatic focusing apparatus of the present invention will be described in detail with reference to FIG. 3 and FIG. FIG. 3 is a flowchart showing the operation of the automatic focusing apparatus of the present invention, and FIG. 4A is a diagram showing the distance measurement area at the time of normal photographing in the first embodiment of the present invention. (B) is a diagram showing a distance measurement area at the time of still state shooting in the first embodiment of the present invention. A distance measurement area indicated by a solid line in FIGS. 4A and 4B is a distance measurement area displayed on the operation display unit 216, and a distance measurement area indicated by a dotted line is a measurement area not displayed on the operation display part 216. It is a distance area.

  First, in step S301, the state of the main switch 223 is detected. If it is ON, the process proceeds to step S302. Here, the function of the main switch 223 is to turn on the system. In step S302, the remaining capacity of the recording medium 222 is checked. If the remaining capacity is sufficient to record the subject, the process proceeds to step S304. Otherwise, the process proceeds to step S303. In step S303, a warning is given that the remaining capacity of the recording medium 222 is insufficient, and the process returns to step S301. The warning may be displayed on the operation display unit 216, a warning sound may be emitted from a sound output unit (not shown), or both may be performed. In step S304, the focus lens 205 is reset according to the flowchart of FIG.

  In step S305, whether or not the camera is stationary is detected by the stationary detection sensor 229. If the camera is stationary, the process proceeds to step S307, and if not, the process proceeds to step S306.

  In step S306, the distance measurement area in the shooting screen of the image sensor 209 is the distance measurement area indicated by the solid line in FIG. 4A set during normal shooting in a calculation memory (not shown) built in the system control CPU 215. The distance measurement area is stored and displayed on the operation display unit 216 as indicated by the solid line in FIG. In step S307, since the camera is detected to be stationary by the stationary detection sensor 229, a distance measurement area indicated by a solid line in FIG. 4B having a smaller area than that during normal photographing is incorporated in the system control CPU 215. The distance measurement area as shown by the solid line in FIG. 4B is displayed on the operation display unit 216.

  In step S308, the state of the switch SW1 is checked. If it is ON, the process proceeds to step S310, and if not, the process proceeds to step S309. Here, the function of SW1 is to perform a shooting standby operation such as AF or AE. In step S309, the state of the main switch 223 is checked. If it is ON, the process proceeds to step S305, and if not, the process proceeds to step S301. In step S310, subject luminance is calculated from the output signal of the image sensor 209. In step S311, an AF operation is performed according to the flowchart of FIG. At this time, if the subject brightness is lower than a predetermined value, the auxiliary light source 228 is projected toward the subject for a predetermined time.

  In step S312, the state of SW2 is checked. If ON, the process proceeds to step S314; otherwise, the process proceeds to step S313. Here, the function of SW2 is to perform photographing after operation of SW1. In step S313, the state of SW1 is checked. If ON, the process returns to step S312; otherwise, the process returns to step S305. In step S314, a photographing operation is performed according to the flowchart of FIG. In step S315, the remaining capacity of the recording medium 222 is checked. If the remaining capacity is sufficient to record the subject, the process proceeds to step S316, and if not, the process proceeds to step S303. In step S316, the state of SW2 is checked, and if not ON, the process proceeds to step S313.

  Hereinafter, the focus lens reset in step S304 in FIG. 3 will be described with reference to the flowchart in FIG. FIG. 5 is a flowchart of the focus lens reset operation (step S304) in the flowchart of FIG.

  In this description, the relationship between the position of the photointerrupter 206 and the output is shown in FIG. 8, and when the focus lens 205 is on the infinite end side with respect to the photointerrupter output switching position, the output of the photointerrupter 206 is “Lo”. When it is on the near end side, it is assumed to be “Hi”.

  First, in step S501, the output state of the photo interrupter 206 is checked. If “Lo”, the process proceeds to step S502, and if not, the process proceeds to step S503. In step S502, it is determined that the focus lens 205 is on the infinite end side with respect to the photo interrupter output switching position based on the output of the photo interrupter 206 in step S501. Therefore, the focus lens 205 is moved one step to the closest end side. In step S503, the output state of the photo interrupter 206 is checked. If “Hi”, the process proceeds to step S504, and if not, the process proceeds to step S505. In step S504, it is determined in step S503 that the focus lens 205 is on the near end side with respect to the photo interrupter output switching position based on the output of the photo interrupter 206, so the focus lens 205 is moved one step toward the infinite end side.

  The operation when the focus lens 205 is reset in this way will be described.

  First, when the position of the focus lens 205 when the main switch 223 is turned on is on the infinite end side with respect to the photointerrupter output switching position, the output of the photointerrupter 206 is “Lo”, so step S501 in FIG. In step S502, the focus lens 205 is moved step by step toward the closest end until the output of the photo interrupter 206 becomes “Hi”. Since the output of the photo interrupter 206 is switched to “Hi” when the photo interrupter output switching position in FIG. 8 is exceeded, this time is infinite until the output of the photo interrupter 206 becomes “Lo” in accordance with steps S503 and S504 in FIG. It is moved step by step to the end side. Thus, the focus lens 205 finally stops at the reset position in FIG. If the position of the focus lens 205 when the main switch 223 is turned on is close to the photo interrupter output switching position, the focus lens 205 is moved only to the infinite end side and the output of the photo interrupter 206 is output. Stop when “Lo” becomes “Lo”. Thus, as in the case where the position of the focus lens 205 when the main switch 223 is turned on is on the infinite end side with respect to the photo interrupter output switching position, the focus lens 205 is finally set to the reset position in FIG. Stop on.

  Hereinafter, the subroutine of the AF operation in step S311 in the flowchart of FIG. 3 will be described with reference to the flowchart of FIG. The AF operation is performed by detecting a peak of a high frequency component (hereinafter referred to as a focus evaluation value) of a signal obtained from the image sensor. FIG. 6 is a flowchart of the subroutine of the AF operation (step S311) in the flowchart of FIG.

  First, in step S601, the focus lens 205 is moved to the scan start position.

  Here, it is assumed that the scan start position is set to an infinite end in the distance measurement range. In step S602, the focus evaluation value of the distance measurement area stored in step S306 or step S307 and the position of the focus lens 205 are stored. When the stepping motor is used as the focus lens drive motor 207, the position of the focus lens 205 is detected as a relative position from the reset position detected by the photo interrupter 206 for reset position detection. In step S603, it is checked whether or not the lens position is at the end position. If it is the end position, the process proceeds to step S605; otherwise, the process proceeds to step S604. Here, the scan end position is set to the closest end in the distance measurement range. In step S604, the focus lens 205 is driven and moved in the closest direction by a predetermined amount.

  In step S605, the maximum focus evaluation value stored in step S602 is obtained for each distance measurement area, and the position of the focus lens 205 at that time is extracted. In step S606, when there are a plurality of distance measurement areas stored in step S306 or step S307, the measurement value to be focused from the combination of the maximum focus evaluation value obtained in step S605 and the lens position for each distance measurement area. Although the distance area is selected by a preset calculation, in this embodiment, since there is only one distance measurement area, nothing is performed here. In step S607, the focus lens 205 is moved to the position where the focus evaluation value shows the maximum value in step S605.

  Hereinafter, the subroutine of the photographing operation in step S314 in the flowchart of FIG. 3 will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart of the subroutine of the photographing operation (step S314) in the flowchart of FIG.

  First, in step S701, the subject brightness is measured. In step 702, the image sensor 209 is exposed in accordance with the subject brightness measured in step S701. In step S703, the preprocessing circuit 211 performs output noise removal of the image sensor 209, nonlinear processing performed before A / D conversion, and the like. In step S704, the analog signal from the pre-processing circuit 211 is converted into a digital signal. In step S705, the output data from the A / D converter 212 is temporarily stored in the buffer memory 213 via the memory controller 214. In step S706, the data in the buffer memory 213 is transferred to the recording medium 222 such as a memory card attached to the camera body via the memory controller 214 and the recording interface 221.

  As described above, by controlling the camera, the electronic still camera or the like using this embodiment reduces the area of the distance measurement area when the camera is detected to be stationary. Thus, it is possible to prevent erroneous ranging due to the presence of subjects having different subject distances, and to perform ranging with higher accuracy.

  In the above description, the stationary detection sensor is configured to detect whether or not the camera is stationary in conjunction with the camera being attached to a fixing member such as a tripod. The detected angular velocity sensor may be used to detect whether the camera is stationary based on the amount of movement of the camera within a certain time. This configuration is shown in FIG. As shown in the figure, the stationary detection sensor 229 includes an angular velocity sensor 1201 and an integration circuit 1202. The angular velocity detected by the angular velocity sensor 1201 is integrated by the integrating circuit 1202, and the amount of movement within a certain time is obtained. A value detected as the amount of movement is processed by the CPU 215, and a stationary state is detected when the amount of movement is less than a certain threshold. This angular velocity detection sensor may be used in combination with a camera for vibration isolation purposes.

  Hereinafter, the second embodiment of the automatic focusing device of the present invention will be described with reference to FIG. 9 in the case where it is used in an electronic camera as in the first embodiment. FIG. 9A is a diagram showing a distance measuring area at the time of normal photographing in the second embodiment of the present invention, and FIG. 9B is a diagram at the time of stationary state photographing in the second embodiment of the present invention. It is a figure which shows a ranging area. As in this embodiment, since there are a plurality of distance measuring areas, the main subject can be focused without taking steps such as AF lock even if the main subject is not at the center of the shooting screen, and instant shooting can be provided. .

  Regions indicated by solid lines in FIGS. 9A and 9B are distance measurement regions that are stored in the CPU 215 as distance measurement regions and displayed on the operation display unit 216. The second embodiment is characterized by the following operations.

  The second embodiment also performs control according to the flowchart of FIG. A description of the same operation as that of the first embodiment is omitted. In step S306, the distance measurement area on the imaging screen of the image sensor 209 is stored in a calculation memory (not shown) incorporated in the system control CPU 215 as a distance measurement area as indicated by a solid line in FIG. 216 is displayed. In step S307, the stationary detection sensor 229 stores the area indicated by the solid line in FIG. 9B, which has a smaller area than that in FIG. 9A, as a distance measurement area in a calculation memory (not shown) built in the system control CPU 215 and operates the operation. It is displayed on the display unit 216.

  In the AF operation subroutine in step S311, the following operation is performed.

  First, in step S601, the focus lens 205 is moved to the scan start position.

  Here, it is assumed that the scan start position is set to an infinite end in the distance measurement range. In step S602, the focus evaluation value and the position of the focus lens 205 for every distance measurement area stored in step S306 or step S307 are stored. When the stepping motor is used as the focus lens drive motor 207, the position of the focus lens 205 is detected as a relative position from the reset position detected by the photo interrupter 206 for reset position detection. In step S603, it is checked whether or not the lens position is at the end position. If it is the end position, the process proceeds to step S605; otherwise, the process proceeds to step S604. Here, the scan end position is set to the closest end in the distance measurement range. In step S604, the focus lens 205 is driven and moved in the closest direction by a predetermined amount.

  In step S605, the maximum focus evaluation value stored in step S602 is obtained for each of the plurality of distance measurement areas, and the position of the focus lens 205 at that time is extracted. In step S606, for a plurality of distance measurement areas stored in step S306 or step S307, a predetermined distance measurement area to be focused is calculated from the combination of the maximum focus evaluation value obtained in step S605 and its lens position. Select by. In step S607, the focus lens 205 is moved to a position where the focus evaluation value shows the maximum value in the distance measurement area selected in step S606.

  When it is detected that the camera is stationary in the electronic still camera or the like having a plurality of ranging areas using the present embodiment as shown in FIG. 9 by controlling the camera as described above. This reduces the area of the distance measurement area, prevents erroneous distance measurement due to the presence of subjects with different subject distances in the area, and enables more accurate distance measurement.

  Hereinafter, the case where the third embodiment of the automatic focusing apparatus of the present invention is used in an electronic camera as in the first embodiment will be described with reference to FIG. Here, FIG. 10A is a diagram showing a distance measuring area during normal photographing in the third embodiment of the present invention, and FIG. 10B is a diagram during stationary state photographing in the third embodiment of the present invention. It is a figure which shows a ranging area. In this embodiment, during normal shooting, a plurality of distance measurement areas are provided, providing quick shooting when the main subject is not in the center of the shooting screen, and providing a distance measurement area in the center of the screen when shooting in a stationary state. Higher ranging accuracy can be obtained.

  10A and 10B are distance measurement areas that are stored in the system control CPU 215 and displayed on the operation display unit 216 in steps S306 and S307 described later. The third embodiment is characterized in that it operates as follows.

  The third embodiment also performs control according to the flowchart of FIG. A description of the same operation as that of the first embodiment is omitted. In step S306, a plurality of distance measurement areas (indicated by solid lines in FIG. 10A) determined as normal shooting in step S305 are stored in the CPU 215 and displayed on the operation display unit 216. In step S307, one distance measurement area (indicated by a solid line in FIG. 10B) determined to be in the still state shooting in step S305 is stored in the CPU 215 and displayed on the operation display unit 216.

  In the AF operation subroutine in step S311, the following operation is performed. In step S602, the focus evaluation value and the position of the focus lens 205 for every distance measurement area stored in step S306 or step S307 are stored. In step S606, for all the distance measurement areas stored in step S306 or S307, the distance measurement area to be focused on is calculated in advance from the combination of the maximum focus evaluation value obtained in step S605 and its lens position. Select by.

  As described above, by controlling the camera, in the electronic still camera or the like as shown in FIG. 10 in which the distance measurement area using this embodiment is detected, the camera is stationary. By reducing the area of the distance measurement area, it is possible to prevent erroneous distance measurement due to the presence of subjects having different subject distances within the area, and it is possible to perform distance measurement with higher accuracy.

  Hereinafter, the case where the fourth embodiment of the automatic focusing device of the present invention is used in an electronic camera as in the first embodiment will be described with reference to FIG. FIG. 11A is a diagram showing a distance measuring area at the time of normal photographing in the third embodiment of the present invention, and FIG. 11B is a diagram at the time of still state photographing in the third embodiment of the present invention. It is a figure which shows a ranging area. In this embodiment, a plurality of distance measurement areas are provided during normal shooting, providing instant shooting when the main subject is not at the center of the shooting screen, and a distance measurement area different from that during normal shooting is displayed on the screen during still shooting. By providing a plurality from the center of the screen, it is possible to provide a quick image to the main subject near the center of the screen.

  The fourth embodiment also performs control according to the flowchart of FIG. A description of the same operation as that of the first embodiment is omitted. In step S306, a plurality of distance measuring areas (indicated by solid lines in FIG. 11A) determined as normal shooting in step S305 are stored in a calculation memory (not shown) incorporated in the system control CPU 215, and an operation display unit Display to 216. In step S307, a plurality of distance measuring areas (indicated by solid lines in FIG. 11B) determined to be in the still state shooting in step S305 are stored in a calculation memory (not shown) incorporated in the system control CPU 215 for operation display. To the part 216.

  In the AF operation subroutine in step S311, the following operation is performed. In step S606, for a plurality of distance measurement areas stored in step S306 or step S307, a predetermined distance measurement area to be focused is calculated from the combination of the maximum focus evaluation value obtained in step S605 and its lens position. Select by.

  As described above, by controlling the camera, in an electronic still camera or the like as shown in FIG. By reducing the area, it is possible to prevent erroneous distance measurement due to the presence of subjects having different subject distances in the region, and more accurate distance measurement is possible.

It is a figure which shows the example in which the object from which object distance differs exists in a ranging area simultaneously. 1 is a configuration block diagram of an electronic camera to which the present invention is applied. It is a flowchart showing operation | movement of the electronic camera to which the 1st Example of this invention is applied. (A) The figure which shows the ranging area at the time of normal imaging | photography in 1st Example of this invention.

(B) The figure which shows the ranging area at the time of still state imaging | photography in 1st Example of this invention.
4 is a flowchart illustrating a reset operation of the focus lens in FIG. 3. 4 is a flowchart of an AF operation subroutine in FIG. 3. It is a flowchart of the subroutine of imaging | photography operation | movement in FIG. It is a figure showing the relationship between the position of a photo interrupter, and an output. (A) The figure which shows the ranging area at the time of normal imaging | photography in the 2nd Example of this invention.

(B) The figure which shows the ranging area at the time of still state imaging | photography in 2nd Example of this invention.
(A) The figure which shows the ranging area at the time of normal imaging | photography in the 3rd Example of this invention.

(B) The figure which shows the ranging area at the time of still state imaging | photography in 3rd Example of this invention.
(A) The figure which shows the ranging area at the time of normal imaging | photography in the 4th Example of this invention.

(B) The figure which shows the ranging area at the time of still state imaging | photography in 4th Example of this invention.
The figure which shows the structure using an angular velocity sensor for the stationary detection sensor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 201 Fixed lens 202 Aperture and shutter 203 Motor 204 Mechanical drive circuit 205 Focus lens 206 Photo interrupter 207 Motor 208 Focus lens drive circuit 209 Image sensor 210 Timing signal processing circuit 211 Pre-processing circuit 212 A / D converter 213 Buffer memory 214 Memory Controller 215 Microcontroller 216 Operation display unit 217 Operation unit 218 Non-volatile memory 219 Interface 220 Expansion unit 221 Interface 222 Recording medium 223 Main switch 224 Switch 225 Shooting switch 226 Mode switch 227 Flash 228 Auxiliary light source 229 Stationary detection sensor 1201 Angular velocity sensor 1202 Integration circuit

Claims (9)

A stationary detection unit that detects that the imaging device is stationary, a focus lens that performs focus adjustment of a subject image, a focus lens driving unit that drives the focus lens, and a subject image formed by the focus lens. An image sensor for converting into an electrical signal, an extraction means for extracting a signal indicating a high-frequency component of a subject from a signal on the light-receiving surface of the image sensor corresponding to one or a plurality of ranging areas set on a photographing screen, A focus position detecting means for detecting a focus position with respect to an output signal of each distance measurement area by the extraction means, and a distance measurement area to be focused is selected based on detection information from the focus position detection means. A focus area driving means for driving the focus lens to a focus position of a focus detection area selecting means and a focus detection area selected by the focus area selection means; And control means for controlling,
An automatic focusing device characterized in that an area of the distance measurement area is reduced based on a detection result of the stationary detection means.   The automatic focusing device according to claim 1, wherein the stationary detection means operates in conjunction with a setting means on a fixed member such as a tripod provided in the imaging apparatus.   The automatic focusing device according to claim 1, wherein the stationary detection means is an angular velocity sensor provided in the imaging device. A stationary detection unit that detects that the imaging device is stationary, a focus lens that performs focus adjustment of a subject image, a focus lens driving unit that drives the focus lens, and a subject image formed by the focus lens. An image sensor for converting into an electrical signal, an extraction means for extracting a signal indicating a high-frequency component of a subject from a signal on the light-receiving surface of the image sensor corresponding to one or a plurality of ranging areas set on a photographing screen, A focus position detecting means for detecting a focus position with respect to an output signal of each distance measurement area by the extraction means, and a distance measurement area to be focused is selected based on detection information from the focus position detection means. A focus area driving means for driving the focus lens to a focus position of a focus detection area selecting means and a focus detection area selected by the focus area selection means; And control means for controlling,
An automatic focusing device characterized in that, based on the detection result of the stationary detection means, a smaller area of a part of the plurality of distance measurement areas is used as a distance measurement area.   5. The automatic focusing device according to claim 4, wherein the stationary detection means operates in conjunction with a setting means on a fixing member such as a tripod provided in the imaging apparatus.   The automatic focusing device according to claim 4, wherein the stationary detection means is an angular velocity sensor provided in the imaging device. A stationary detection unit that detects that the imaging device is stationary, a focus lens that performs focus adjustment of a subject image, a focus lens driving unit that drives the focus lens, and a subject image formed by the focus lens. An image sensor for converting into an electrical signal, an extraction means for extracting a signal indicating a high-frequency component of a subject from a signal on the light-receiving surface of the image sensor corresponding to one or a plurality of ranging areas set on a photographing screen, A focus position detecting means for detecting a focus position with respect to an output signal of each distance measurement area by the extraction means, and a distance measurement area to be focused is selected based on detection information from the focus position detection means. A focus area driving means for driving the focus lens to a focus position of a focus detection area selecting means and a focus detection area selected by the focus area selection means; And control means for controlling,
An automatic focusing device characterized in that, based on the detection result of the stationary detection means, one or a plurality of areas having a smaller total area provided separately from the distance measuring area are used as the distance measuring area.   8. The automatic focusing device according to claim 7, wherein the stationary detection means operates in conjunction with a setting means on a fixing member such as a tripod provided in the imaging apparatus.   8. The automatic focusing device according to claim 7, wherein the stationary detection means is an angular velocity sensor provided in the imaging device.

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