JP2005189533A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device in which appropriate focusing adjustment can be made according to a specified position when the imaging device has been set in a mode for executing the function of specifying an arbitrary subject as a focal point. <P>SOLUTION: When the FFP mode is set and the specified position for focusing is within the ranging area AR 2 of a ranging part, focusing adjustment is roughly made using a focal distance detected by the ranging part and then the focusing adjustment is made in detail by a climbing detection system. When the FFP mode is set and the specified position for focusing is out of the ranging area AR2 of the ranging part, focusing adjustment is made using the climbing detection system only. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention has a function of designating an arbitrary subject as a point to be focused (focusing point), a focus adjustment function by an external light passive method having a plurality of distance measuring points, and a focus adjustment function by a so-called hill-climbing detection method. The present invention relates to an imaging apparatus provided.

  In an imaging apparatus, apart from an imaging optical system and an imaging element for obtaining an image to be recorded, a plurality of optical systems (ranging optical systems) and imaging elements (corresponding to each ranging optical system) A distance measuring image pickup device), and each of the distance image pickup elements receives a light image formed through the distance measuring optical system to perform an image pickup operation and output the distance measuring image pickup device. A so-called external light passive focus adjustment method is known in which the subject distance is calculated based on the amount of deviation of the imaging position of each optical image obtained from the above, and the focus lens is driven to the focal position corresponding to the subject distance. (For example, see Patent Document 1 below).

  As another focus adjustment method of the image pickup apparatus, the focus lens position where the contrast of the image obtained by the image pickup operation is maximized while alternately driving the focus lens in the optical axis direction and the image pickup operation by the image pickup device. A so-called hill-climbing detection type focus adjustment method in which a focus lens is located at the position is also known.

On the other hand, a technique has been proposed in which an imaging apparatus has a function of designating an arbitrary subject among subjects displayed on an image display unit as a focal point and a function of focusing on the designated focal point ( For example, see Patent Document 2 below).
JP-A-9-212315 JP 2003-125274 A

  When comparing the focus adjustment method using the external light passive method and the focus adjustment method using the hill-climbing detection method, the focus adjustment method using the external light passive method performs the focus adjustment in a shorter time than the focus adjustment using the hill-climbing detection method. On the other hand, the external light passive method measures the distance with an optical system different from the imaging optical system, converts the distance value obtained by the distance measurement into the driving amount of the focus lens in the imaging optical system, and Since the focus lens is driven based on the driving amount, a calculation error and a mechanical error at the time of driving / stopping the focus lens occur at that time. Furthermore, at the wide-side focal length of the imaging optical system, there is a problem that only a part of the entire captured image can be measured (if the entire area can be measured, the distance measuring device can be increased in size and cost). In addition, depending on the subject distance, there arises a problem of parallax (parallax) between the imaging optical system and the distance measuring optical system. On the other hand, the focus adjustment method using the hill-climbing detection method is a target region where the entire area of the captured image can be adjusted and the focus adjustment accuracy is high, but the time required for the focus adjustment compared to the external light passive method. long.

  Therefore, in order to perform focus adjustment that balances the accuracy and time of focus adjustment, both focus adjustment methods are combined, and the focus lens is driven roughly at the approximate position by the external light passive method to adjust the focus roughly. Then, it is conceivable to perform focus adjustment with high accuracy by the hill-climbing detection method using the image of the image sensor at the position corresponding to the main subject detected during the distance measurement in the external light passive method.

  However, in an imaging apparatus equipped with a function for designating an arbitrary subject as a focal point, when the mode is set to execute the function, the focus adjustment always combines both the above-described focus adjustment methods. For example, when the designated focal point is set outside the distance measuring range of the external light passive type distance measuring device, the external light passive type focus adjustment is performed at the designated focal point. It is not possible.

  As described above, when setting a mode in which an arbitrary subject is designated as a focal point, depending on the designated focal point, a focus obtained by combining a focus adjustment method of an external light passive method and a focus adjustment method of a hill-climbing detection method. Adjusting is not necessarily the best focus adjustment method.

  The present invention has been made in view of such circumstances, a function for designating an arbitrary subject as a focal point, a function for performing focus adjustment by an external light passive method, and a function for performing adjustment by a hill-climbing detection method. In an imaging apparatus equipped with a camera, an object is to perform appropriate focus adjustment according to the position of a designated in-focus point when setting a mode for executing a function for specifying an arbitrary subject as the in-focus point.

  The invention described in claim 1 includes an imaging unit that photoelectrically converts an optical image of a subject, and a focus adjustment unit that focuses a focal position of the imaging lens on an imaging surface of the imaging unit. An imaging optical system for forming a subject image on the imaging surface of the means, an evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means, a pair of distance measuring optical systems, and each distance measuring optical An external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to the system and an input for specifying a focal point from the imaging area of the imaging means is possible. Using the mode setting means for setting to the in-focus manual setting mode, the operating means for performing input for designating the in-focus position, and the evaluation by the evaluation means, and causing the focus adjustment means to perform the focusing operation By the first control means and the distance measuring means. A second control unit that causes the focus adjusting unit to perform a focusing operation using the detected subject distance and the evaluation by the evaluation unit, and when the in-focus manual setting mode is set, the operation unit An imaging apparatus comprising switching means for switching between control by the first control means and control by the second control means in accordance with a position designated as a focal point.

  According to a second aspect of the present invention, in the imaging apparatus according to the first aspect, the second control unit performs a focusing operation on the focus adjusting unit using the subject distance detected by the distance measuring unit. Then, the focus adjustment unit is caused to perform a focusing operation by using the evaluation by the evaluation unit.

  According to a third aspect of the present invention, in the imaging apparatus according to the first or second aspect, the switching unit is configured such that a position designated as a focal point by the operation unit is within a distance measuring range of the distance measuring unit. In some cases, the control is set to be controlled by the second control means, and when it is outside the distance measurement possible range of the distance measurement means, the control is set to control by the first control means.

  According to a fourth aspect of the present invention, in the imaging apparatus according to any one of the first to third aspects, when the subject distance is smaller than a predetermined threshold, regardless of a position designated as a focal point by the operation unit, The switching means is set to control by the first control means.

  The invention according to claim 5 includes imaging means for photoelectrically converting a light image of a subject, and focus adjusting means for focusing a focus position of a photographing lens on an imaging surface of the imaging means. An imaging optical system for forming a subject image on the imaging surface of the means, an evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means, a pair of distance measuring optical systems, and each distance measuring optical An external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to the system and an input for specifying a focal point from the imaging area of the imaging means is possible. Using the mode setting means for setting to the in-focus manual setting mode, the operating means for performing input for designating the in-focus position, and the evaluation by the evaluation means, and causing the focus adjustment means to perform the focusing operation By the first control means and the distance measuring means. A second control unit that causes the focus adjusting unit to perform a focusing operation using the detected subject distance and the evaluation by the evaluation unit, and when the in-focus manual setting mode is set, the operation unit By prohibiting means for prohibiting the position designated as the focal point from being set in a range incapable of distance measurement by the distance measuring means, and when the setting is prohibited by the prohibiting means, the first control means An imaging device comprising: setting means for setting to control.

  According to a sixth aspect of the present invention, the imaging apparatus includes an imaging unit that photoelectrically converts a light image of a subject, and a focus adjustment unit that focuses a focal position of the imaging lens on an imaging surface of the imaging unit. An imaging optical system for forming a subject image on the imaging surface of the means, an evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means, a pair of distance measuring optical systems, and each distance measuring optical An external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to the system and an input for specifying a focal point from the imaging area of the imaging means is possible. Using the mode setting means for setting to the in-focus manual setting mode, the operating means for performing input for designating the in-focus position, and the evaluation by the evaluation means, and causing the focus adjustment means to perform the focusing operation By the first control means and the distance measuring means. When the detected object distance and the evaluation by the evaluation means are used, the second control means for causing the focus adjustment means to perform a focusing operation, and the focus manual setting mode are set, the first focus setting mode is set. An image pickup apparatus comprising: setting means for setting control by the control means.

  According to the first aspect of the present invention, when the in-focus manual setting mode is set, the in-focus operation using the evaluation by the evaluation unit is performed according to the position designated as the in-focus point, or the ranging unit Since the focus operation using the subject distance detected by the above and the evaluation by the evaluation means is switched, appropriate focus adjustment can be performed according to the position designated as the focus.

  According to the second aspect of the present invention, the second control unit causes the focus adjusting unit to perform a focusing operation using the subject distance detected by the distance measuring unit, and then the evaluation by the evaluation unit. Since the focus adjustment means is caused to perform a focusing operation using the lens, when the control is set by the second control means, the focus adjustment in which the precision and time of the focus adjustment are compatible can be performed. .

  According to the third aspect of the present invention, when the position designated as the focal point by the operation means is within the distance measurement possible range of the distance measurement means, the object distance detected by the distance measurement means and the evaluation by the evaluation means When the focusing operation using the distance measuring means is out of the distance measurement possible range, the focusing operation using the evaluation by the evaluation means is performed. Is within the distance measurement range of the distance measuring means, the focus adjustment can be performed in a short time compared with the case where the focusing operation using only the evaluation by the evaluation means is performed, and the position designated as the in-focus position. Is outside the range that can be measured by the distance measuring means, erroneous focus adjustment is performed by the distance measuring means, or extra focus adjustment time is required by performing a useless distance measuring operation by the distance measuring means. Can prevent .

  According to the fourth aspect of the present invention, when the subject distance is smaller than the predetermined threshold, that is, the parallax between the imaging unit and the distance measuring unit is increased, and is designated as the focal point by the operation unit. The focus operation using the evaluation by the evaluation means is performed regardless of the position designated as the focal point by the operation means when the position to be out of the distance measurement possible range of the distance measurement means is high. Therefore, if the position designated as the in-focus point is outside the range that can be measured by the distance measuring means, incorrect focus adjustment is performed by the distance measuring means, or the distance measuring operation by the unnecessary distance measuring means is not performed. Focus adjustment time can be shortened.

  According to the fifth aspect of the present invention, when the in-focus manual setting mode is set, the position designated as the in-focus point by the operation unit is prohibited from being set in a range incapable of ranging by the distance measuring unit. Thus, since the focusing operation is performed using the evaluation by the evaluation unit, it is possible to perform the focus adjustment that balances the accuracy and time of the focus adjustment within the distance measurement possible range of the distance measurement unit.

  According to the sixth aspect of the present invention, when the in-focus manual setting mode is set, the in-focus operation is performed using the evaluation by the evaluation unit. When the distance is out of the range that can be measured, incorrect focus adjustment is performed by the distance measurement means, or the focus adjustment time can be shortened by not performing the distance measurement operation by the unnecessary distance measurement means. .

  Hereinafter, an embodiment of an imaging device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a front view showing the configuration of the imaging apparatus, and FIG. 2 is a rear view of the imaging apparatus.

  As shown in FIGS. 1 and 2, the imaging apparatus 1 includes an imaging optical system 2 disposed at a proper position on the front surface, a mode setting dial 3 disposed at a proper position on the upper surface, and a shutter disposed at an upper corner. A button 4, an LCD (Liquid Crystal Display) 5 disposed on the left side of the back surface, a cross operation unit 6 disposed on the side of the LCD 5, and a push button 7 disposed on the inner side of the cross operation unit 6. A set button group 8 disposed below the LCD 5, an electronic view finder (hereinafter abbreviated as EVF) 9 disposed above the LCD 5, and an imaging optical system 2. A photometric unit 10, a distance measuring unit 11 disposed adjacent to the photometric unit 10, a flash 12 disposed above the EVF 9, and an AF auxiliary light emitting unit 13 disposed at an appropriate position on the front surface. Yes.

  Referring to FIG. 8, the imaging optical system 2 includes a zoom lens 19 for changing a photographing magnification (focal length) and a focus lens 20 for adjusting a focal position (corresponding to a focus adjusting unit in claims). ) And a diaphragm 21 for adjusting the amount of light to the image sensor 23 are arranged in the direction of the optical axis L1 (see FIG. 6) in the lens barrel 2a provided so as to protrude from the apparatus main body 1A. The optical image of the subject is taken in and formed on the image sensor 23. The imaging magnification (focal length) is changed and the focal position is adjusted by driving each lens of the imaging optical system 2 in the direction of the optical axis L1 by a drive system such as a motor (not shown).

  The mode setting dial 3 is a substantially disk-shaped member that can be rotated in a plane substantially parallel to the upper surface of the imaging device 1, and includes a shooting mode for shooting a still image or a moving image, a playback mode for playing back a recorded image, Alternatively, the mode and function mounted in the imaging apparatus 1 such as switching of power ON / OFF can be selected alternatively. Although not shown, on the upper surface of the mode setting dial 3, characters indicating the respective functions are written at predetermined intervals along the outer peripheral edge of the mode setting dial 3, and are opposed to indexes provided at appropriate positions on the apparatus main body 1 a side. The function corresponding to the character set at the position is executed.

  The shutter button 4 is a button that is pressed in two stages, that is, a half-pressing operation in which it is pressed halfway and a full-pressing operation in which it is fully pressed. In the shooting mode, when the shutter button 4 is not operated, an optical image of the subject is captured at a constant cycle (for example, every 1/30 (second)), and images generated by the imaging are sequentially displayed on the LCD 5 and the EVF 9. The display is switched. The series of images displayed on the LCD 5 or the like at this time is hereinafter referred to as a live view image in the sense that the state of the subject is displayed in substantially real time. By displaying the live view image, the photographer can visually recognize the state of the subject on the LCD 4.

  When the shutter button 4 is half-pressed, in addition to the display of the live view image, a shooting preparation process, mainly detecting the subject brightness and setting an exposure control value, and adjusting the focus of the imaging optical system 2 are performed. Processing to be performed is performed. Further, when the shutter button 4 is fully pressed, an object image to be recorded in an image storage unit 35 to be described later is captured with the exposure control value set when the shutter button 4 is pressed halfway. The half-pressing operation of the shutter button 4 is detected by turning on a switch S1 (not shown), and the full pressing operation of the shutter button 4 is detected by turning on a switch S2 (not shown).

  The LCD 5 includes a color liquid crystal panel, and displays a live view image, a reproduction display of a recorded image, and the like, and displays a setting screen for functions and modes installed in the imaging apparatus 1. FIG. 3 shows how a plurality of subjects are displayed on the display screen of the LCD 5. Instead of the LCD 5, an organic EL or a plasma display device may be used.

  The cross operation unit 6 includes an annular member having pressing parts 6a to 6d arranged in a cross shape, and the pressing part 6a is provided by a contact (switch) (not shown) provided corresponding to each pressing part 6a to 6d. ˜6d pressing operation is detected, the photographing magnification is changed (the zoom lens 19 is moved in the wide direction or the tele direction), the frame advance of the recorded image to be reproduced on the LCD 5, and the photographing condition This is for inputting an instruction for setting (aperture value, shutter speed, presence / absence of flash emission, etc.).

  In addition, the present embodiment is provided with a flex focus point mode (hereinafter referred to as FFP mode) that can focus on an arbitrary subject in the shooting area. As shown in FIG. When set, the cursor CSR indicating the focus position (focus position at the focus position) is displayed superimposed on the subject image on the display screen of the LCD 5 or EVF 9. FIG. 3A shows a state in which the cursor CSR is displayed at the approximate center of the display screen of the LCD 5. Then, as shown in FIG. 3B, the cross operation unit 6 has a function of changing the position of the cursor CSR. FIG. 3B shows that the cursor CSR is moved in the direction of arrow P by operating 6a and 6d of the cross operation unit 6. This FFP mode corresponds to the in-focus manual setting mode in the claims.

  Returning to FIG. 1 and FIG. 2, the push button 7 is used to input for instructing the setting of the FFP mode and the determination of the designated position of the focus. Note that after the FFP mode is set by pressing the push button 7, an instruction to confirm the designated position of the focus is input by performing the pressing operation again. In addition, the cross operation part 6 and the push button 7 are equivalent to the operation means in a claim.

  Although not described in detail, the setting button group 8 is a button for performing operations on various functions installed in the imaging apparatus 1.

  The EVF 9 includes an unillustrated color liquid crystal panel and an eyepiece, and uses the luminous flux that passes through the photographing lens and is separated and guided by the unillustrated separation means and the light guide means to display an image of the subject on the color liquid crystal panel. The photographer can view a subject image similar to the subject image displayed on the display screen of the LCD 5 through the eyepiece lens by looking into the eyepiece window 9a. On the color liquid crystal panel of the EVF 9, a frame F indicating a distance measuring area AR2 of the distance measuring unit 11 described later is displayed. When the photographer looks into the eyepiece window 9a, the frame is superimposed on the image. F can also be visually recognized. The frame F is also displayed on the display screen of the LCD 5, and the frame F displayed on the display screen of the LCD 5 is shown in FIG.

  Although not shown, the photometric unit 10 includes a photometric optical system and a photometric sensor that captures a light image formed by the optical system, and performs photometry using these mechanisms. The subject brightness is calculated from the output of the photometry unit 10, and the detected subject brightness is used to determine the exposure control value (the exposure time of the image sensor 23 corresponding to the aperture value and the shutter speed).

  The distance measuring unit 11 is for detecting the subject distance in order to drive the focus lens 20 to a position corresponding to the distance (subject distance) from the imaging device 1 to the subject. 4A is a cross-sectional view showing the internal configuration of the distance measuring unit 11 in the present embodiment, and FIG. 4B is a distance measuring sensor in the distance measuring unit 11 when viewed from the arrow Q in FIG. 4A. FIG. 6 is a diagram illustrating a configuration of a unit 16.

  As shown in FIG. 4A, the distance measuring unit 11 has optical axes La and Lb different from the optical axis L1 (see FIG. 6) of the imaging optical system 2, and is a plane orthogonal to the optical axes La and Lb. A pair of distance measuring optical systems 14 and 15 arranged in parallel on the upper side, and a distance measuring sensor unit 16 arranged on a substantially imaging plane of the distance measuring optical systems 14 and 15 are configured. A subject image is picked up using the distance measuring optical systems 14 and 15 and the distance measuring sensor section 16. The output of the ranging sensor unit 16 is used for focus adjustment by an external light passive method (details will be described later).

  As shown in FIG. 4B, the ranging sensor unit 16 includes a plurality of line sensors L1 to L14 made of a solid-state imaging device such as a CCD, and a drive signal for data transfer to the line sensors L1 to L14. And a control circuit (not shown) for generating

  When the longitudinal direction of the line sensors L1 to L14 is the X-axis direction and the direction perpendicular to the X-axis direction is the Y-axis direction, the line sensors L1 to L7 are composed of line sensors L1 to L7 arranged substantially parallel to the Y-axis direction at predetermined intervals. A line sensor group 17 and a line sensor group 18 including line sensors L8 to L14 disposed substantially parallel to the Y axis direction at the predetermined interval are arranged in parallel at a predetermined interval in the X axis direction. .

  A subject optical image is formed on the imaging surface of the line sensor group 17 by the ranging optical system 14, while a subject optical image is formed on the imaging surface of the line sensor group 18 by the ranging optical system 15. Then, based on the pixel signals output from the line sensor groups 17 and 18, the distance to the subject (subject distance) is detected by the principle of triangulation, which will be described later. A range captured by the line sensor group 17 (a range captured by the line sensor group 18) is displayed in the frame F on the LCD 5 and the EVF 9 as the distance measuring area AR2 of the distance measuring unit 11.

  As shown in FIGS. 4 and 5, the distance measurement area AR <b> 2 is vertically and horizontally with respect to the imaging range AR <b> 1 when the zoom lens 19 is positioned at the wide end position where the subject in the widest range is imaged on the imaging device 23. The horizontal length is set to, for example, 50%, that is, an area ratio of 25% (illustrated by a dotted line).

  This is because, when the zoom lens 19 is located at the wide end position, if distance measurement is performed also on a subject located in the periphery of the imaging range AR1, the number of out-of-focus images increases on the contrary. If it is confirmed and an attempt is made to provide a distance measuring unit having a distance measuring area AR2 that is substantially equivalent to the imaging range AR1 when the zoom lens 19 is positioned at the wide end position, the distance measuring sensor unit 16 in the distance measuring unit. As the occupation area (light receiving area) increases, the size of the image pickup apparatus 1 is increased, and the amount of information associated with the increase in the number of pixels causes a burden on the main control unit 46 (described later) (information processing amount). This is because of the increase.

  FIG. 6 is a diagram showing the relationship between the shooting areas AR1 and AR3 when the zoom lens 19 is located at the wide end position and the tele end position, and the distance measuring area AR2 of the distance measuring unit 11.

  As shown in FIG. 6, for example, at a position away from the imaging device 1 by a distance L, when the zoom lens 19 is positioned at the wide (wide angle) end position, the range indicated by the arrow A is the imaging range AR1 of the imaging device 23. When the zoom lens 19 is located at the tele (telephoto) end position, the range indicated by the arrow B is the imaging range AR3 of the image sensor 23, which is smaller than the imaging range AR1 at the wide end position (AR3 <AR1). On the other hand, the distance measurement area AR2 of the distance measurement unit 11 is set to an area ratio of about 25% with respect to the image pickup range AR1 of the image pickup device 23 when the zoom lens 19 is located at the wide end position as described above. It is set larger than the imaging range AR3 of the imaging device 23 at the tele end position.

  By the way, when the subject distance is relatively small (when the subject is relatively close to the imaging device 1), the optical axis L1 of the imaging optical system 2 and the optical axes La and Lb of the distance measuring optical systems 14 and 15 are the same. The difference between the optical image guided to the image sensor 23 via the imaging optical system 2 and the optical image guided to the distance sensor unit 16 via the distance measuring optical systems 14 and 15 of the distance measuring unit 11 ( (Parallax, parallax) occurs. In particular, the parallax is small and hardly causes a problem in a region farther than 3 to 5 m from the imaging device 1, but the parallax becomes relatively large in a region closer than that.

  Therefore, in the imaging apparatus 1, in order to reduce this parallax, the optical axes La and Lb of the distance measuring unit 11 intersect with the optical axis L1 of the imaging optical system 2 at, for example, 3 to 5 m ahead (intersection P). In other words, it is designed to be inclined slightly downward with respect to the optical axis L1 of the imaging optical system 2. As described above, the position of the intersection P is set, for example, 3 to 5 m away from the imaging device 1. The most important subject (main subject) is usually 3 to 5 m away from the imaging device 1 and is photographed. In many cases, the optical axis La, Lb of the distance measuring unit 11 is excessively inclined (the position of the intersection P is set closer to the imaging device 1), and the distance measurement unit 11 performs measurement. This is because there is a possibility that the focus adjustment cannot be reliably performed on the main subject because the distance area AR2 is shifted upward or downward from the center of the imaging range.

  As can be seen from FIG. 6, by driving the zoom lens 19 from the wide-angle side to the telephoto side, the imaging range of the imaging device 23 is narrowed, while the distance measuring area AR2 of the distance measuring unit 11 is constant. The distance measuring area AR2 of the distance unit 11 is relatively large with respect to the imaging range of the imaging device 23, for example, from the state shown in FIG. 5 to the state shown in FIG. The distance measuring unit 11 corresponds to the distance measuring means in the claims.

  Returning to FIG. 1, the flash 12 reflects an arc tube composed of a xenon tube or the like that is converted into light energy by discharging electric energy and outputs flash light (flash light) emitted from the arc tube 1 to the front of the imaging device 1. A reflector, a Fresnel lens that condenses or diffuses flash light within a predetermined range, etc., and when an exposure amount to the image sensor 23 is insufficient, discharge is caused in a discharge tube (not shown). This is a pop-up flash that illuminates with illumination light. The operation of the flash 12 is controlled by a dimming circuit 37 (see FIG. 8) that outputs electric energy to the discharge tube.

  The AF auxiliary light emitting unit 13 includes a light emitting element such as an LED, and outputs auxiliary light when distance measurement is performed even when the brightness and contrast of the subject are small.

  Next, a block configuration of the imaging apparatus 1 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the member etc. which are the same as FIGS.

  The photographic optical system 2 corresponds to the photographic optical system 2 shown in FIG. 1 and includes a zoom lens 19, a focus lens 20, and a diaphragm 21. The zoom lens 19 and the focus lens 20 are driven by the motors M1 and M2 in the direction of the optical axis L1 using a helicoid structure in the lens barrel 2a, and the diaphragm 21 is driven by the motor M3.

  In the photographic optical system 2, with respect to driving of the photographic lens, the photographic lens 2 shoots while being in sliding contact with the encode plate in which a plurality of code patterns are formed at a predetermined pitch in the optical axis L1 direction within the moving range of the photographic lens. A lens position detection unit 22 including an encoder brush that moves integrally with the lens is disposed. The lens position detection unit 22 detects the position of the photographing lens by reading the code pattern on the encoding plate with an encoder brush. The detected position of the photographing lens is used for calculating the focal length.

  The image sensor 23 has a plurality of photoelectric conversion elements, such as photodiodes, that are two-dimensionally arranged in a matrix. The light receiving surfaces of the photoelectric conversion elements have different spectral characteristics, for example, R (red) and G (green). ), B (blue) color filters with a Bayer array CCD (Charge Coupled Device) color area sensor having a 1: 2: 1 ratio. The image sensor 23 converts the light image of the subject formed by the photographing lens into analog electrical signals (image signals) of R (red), G (green), and B (blue) color components. Output as B color image signals. Note that the image sensor 23 may be configured by a solid-state image sensor such as a complementary metal-oxide semiconductor (CMOS).

  The image pickup device 23 performs image pickup operations such as start and end of the exposure operation of the image pickup device 23 and reading of output signals of each pixel (horizontal synchronization, vertical synchronization, transfer) in the image pickup device 23 by a timing control circuit 26 described later. Be controlled. The imaging element 23 corresponds to the imaging means in the claims.

  The signal processing unit 24 performs predetermined analog signal processing on the analog image signal output from the image sensor 23. The signal processing unit 24 includes a CDS (correlated double sampling) circuit and an AGC (auto gain control) circuit, reduces noise of the image signal by the CDS circuit, and adjusts the level of the image signal by the AGC circuit.

  The A / D conversion unit 25 converts the analog R, G, B image signals output from the signal processing unit 24 into a plurality of bits (for example, 10 bits) based on a clock CLK2 output from a timing control circuit 26 described later. Bits) are converted into digital image signals.

  The timing control circuit 26 generates clocks CLK1 and CLK2 based on a reference clock CLK0 output from a main control unit 46, which will be described later. The clock CLK1 is used as the image sensor 23, and the clock CLK2 is used as the A / D conversion unit 25. By outputting each of them, the operations of the image sensor 23 and the A / D converter 25 are controlled.

  The image processing unit 27 converts a black level to a reference black level for each of the R, G, and B digital signals A / D converted by the A / D conversion unit 25 and a light source corresponding to the light source. A white balance circuit (WB circuit) 29 that performs digital signal level conversion of each color component of R (red), G (green), and B (blue) based on a white standard, and R (red) and G (green) ) And B (blue) are provided with a γ correction circuit 30 for correcting the γ characteristics of the digital signals of the respective colors.

  The image memory 31 temporarily stores the image data output from the image processing unit 27 in the photographing mode, and is also used as a work area for performing processing to be described later by the main control unit 46 on the image data. It is. Further, in the reproduction mode, the memory temporarily stores image data read from an image storage unit 35 described later.

  The VRAM 32 has a pixel signal recording capacity corresponding to the number of pixels of the LCD 5, and is a buffer memory between the main control unit 46 and the LCD 5. The VRAM 33 has a pixel signal recording capacity corresponding to the number of pixels of the EVF 9. And a buffer memory between the main control unit 46 and the EVF 9. LCD5 and EVF9 correspond to LCD5 and EVF9 shown in FIG. 2, respectively.

  The drive unit 34 includes motors M1 and M2 that drive the zoom lens 19 and the focus lens 20 in the direction of the optical axis L1, respectively, a motor M3 that drives the diaphragm 21, and the like.

  The image storage unit 35 includes a memory card, a hard disk, and the like, and stores an image generated by the main control unit 46.

  The input operation unit 36 includes the mode setting dial 3, the shutter button 4, the cross operation unit 6 and the push button 7 described above, and inputs operation information to the main control unit 46.

  The light emission control unit 37 controls light emission of the flash 12 based on the light emission control signal output from the main control unit 46, and includes a light control circuit 38 and a light control sensor 39. The light emission control signal includes a light emission preparation instruction, a light emission timing, and a light emission amount.

  The dimming circuit 38 charges a main capacitor (not shown) to emit light when a light emission preparation instruction signal is sent from the main control unit 46, and further synchronizes with the timing signal when a light emission timing signal is sent. Thus, the accumulated charge in the main capacitor is discharged, and the flash 12 is caused to emit light. The light control sensor 39 receives reflected light from the subject simultaneously with the start of exposure during flash photography. When the amount of reflected light received by the light control sensor 39 reaches a predetermined light emission amount, the main control unit 46 sends a light emission stop signal to the light control circuit 38. The light control circuit 38 stops the discharge of the main capacitor in response to the light emission stop signal, whereby the flash 12 emits light with a required light emission amount.

  The distance measuring unit 11 corresponds to the distance measuring unit 11 shown in FIG. 1, and includes the distance measuring optical systems 14 and 15, the distance measuring sensor unit 16, and the sub-control unit 40. The sub-control unit 40 controls the imaging operation by the distance sensor unit 16 and executes subject distance calculation processing using image data obtained by the imaging operation of the distance sensor unit 16. As shown in FIG. 3, the extraction unit 41, the correlation calculation unit 42, the corresponding position detection unit 43, the distance detection unit 44, and the reliability determination unit 45 are functionally configured.

  Here, the subject distance calculation process performed by the distance measuring unit 11 will be described. 9 to 11 are diagrams for explaining the principle of distance calculation by the external light passive method (triangular distance measurement method).

  As shown in FIG. 10, in the distance calculation by the external light passive method, each pixel of each line sensor L1 to L14 is divided into X (pieces) blocks for the left and right line sensor groups 17 and 18, respectively. With respect to a pair of blocks corresponding to each other between the line sensor group 17 and the right line sensor group 18, a pixel shift amount (number of pixels) with matching pixel data is derived, and the subject distance is determined for each block based on the shift amount. Is to be calculated. Specifically, the following processing is performed.

  The extraction unit 41 performs a process of extracting each pixel signal from a predetermined number of pixels including some or all of the pixels corresponding to the left line sensor group 17 and the right line sensor group 18.

  FIG. 11 illustrates the state of each pixel signal extracted from a predetermined number of pixels. The circles in FIG. 11 indicate the level of the pixel signal of each pixel constituting the left and right line sensor groups 17 and 18. It is shown as an example. FIG. 11 shows that extraction processing is performed a predetermined number of times, in this embodiment, 10 times.

  On the left line sensor group 17 side, a predetermined number of pixel data are extracted twice from the pixels located at a predetermined position inside, and the predetermined number of pixel data shifted outward by one pixel in the next two times. This operation is sequentially performed twice every two times, that is, a total of ten times while shifting one pixel every odd number of times. Similarly, on the right line sensor group 18 side, a predetermined number of pieces of pixel data are extracted once from pixels located at a predetermined position inside, and then a predetermined number of pieces of pixel data shifted outward by one pixel are converted into 2 pieces. These operations are sequentially performed every two times, that is, a total of ten times while shifting the pixel by one every even number of times. Hereinafter, a predetermined number of pixel data is referred to as partial image data.

  As described above, the extraction unit 41 extracts partial image data while sequentially switching from the left and right line sensor groups 17 and 18 from the first time to the tenth time shown in FIG. The correlation calculation unit 42 calculates the difference between the corresponding pixel data of the left and right line sensor groups 17 and 18 from the pixel data on the head side (for example, from the left side in FIG. 11) of the partial image data delivered each time. Find and calculate the sum.

  Specifically, among the partial image data extracted by the extraction unit 41 at a certain point in time (any of the first to tenth times), L (i) is the 1st to mth from the left line sensor group 17 side. When each pixel data is (i = 1 to m) and R (j) is each pixel data from 1 to n-th (j = 1 to n) on the right line sensor group 18 side (n = m) Alternatively, the correlation calculation unit 42 calculates the correlation coefficient expressed by the following equation 1 when the number of pixel data of the partial image data is expressed as k.

  The correlation coefficient calculated in this way is temporarily stored in an internal storage unit (not shown) in the sub-control unit 40. Then, correlation coefficient sequences (total 10 correlation coefficient sequences) for each extracted pattern are created. The corresponding position detection unit 43 specifies the number of extractions having the highest degree of correspondence, that is, the smallest correlation coefficient from the correlation coefficient string. In FIG. 11, the fifth extraction is the specific result.

  The distance detection unit 44 converts this identification result into a subject distance from the relationship between the correspondence position (extraction position) and the subject distance that are associated with each other in advance and are tabulated, for example. The lens position stored in advance in association with the calculated subject distance is read out from a table or the like. The reliability determination unit 45 determines that the distance cannot be detected when the contrast of the subject is low or the corresponding position cannot be detected. The above processing is performed for each block, and the subject distance for each block is calculated. Therefore, as shown in FIG. 10, if the line sensor groups 17 and 18 of the distance measuring unit 11 each have Y line sensors and each line sensor is divided into X blocks, the distance measuring unit 11 has X × Y (pieces) distance measuring points.

  Returning to FIG. 8, the main control unit 46 includes a microcomputer in which a storage unit 47 including, for example, a ROM that stores a control program, a flash memory that temporarily stores data, and the like is incorporated, and the imaging apparatus 1 illustrated in FIG. 8. The drive of each member is controlled in association with each other. In the present embodiment, the main control unit 46 functionally includes a mode setting unit 48, an AF control unit 49, and a display control unit 50.

  The mode setting unit 48 receives an operation signal from the mode setting dial 3 and sets a shooting mode for shooting a subject and a playback mode for playing back and displaying a shot image on the LCD 5 or the like. In addition to these functions, the mode setting unit 48 of the present embodiment can receive an operation signal from the push button 7 and focus on an arbitrary subject (designate a point to be focused). Set to FFP mode. The mode setting unit 48 corresponds to the mode setting means in the claims.

  The AF control unit 49 controls the operation of the motor M2 to position the focus lens 20 at the focal position. The imaging apparatus 1 according to the present embodiment is obtained by the function of performing focus adjustment by the external light passive method using the distance measuring unit 11 and the imaging operation of the imaging element 23 until the imaging operation for obtaining the recording image is performed. And a function of performing focus adjustment by a so-called hill-climbing detection method, which will be described later, using the contrast of the image (one parameter indicating the clarity of the image).

  When performing focus adjustment by the external light passive method, the AF control unit 49 instructs the distance measurement unit 11 (sub control unit 40) to perform a distance measurement operation, and the distance measurement value of each block calculated by the sub control unit 40 Based on the distance measurement value obtained by the external light passive method by the distance measurement unit 11, for example, the technique disclosed in Japanese Patent Laid-Open No. 14-298138 proposed by the present applicant is adopted and considered to be the most important. The main subject (mainly a person) to be detected is detected. That is, a three-dimensional coordinate system is set in which the horizontal direction of the shooting area is the X axis, the vertical direction is the Y axis, and the subject distance is an axis perpendicular to the XY plane (Z axis), and the subject distance corresponding to each block is set. Is plotted in this coordinate system to generate a three-dimensional distance image. Then, a person is detected from the distance image based on the ratio of the actual human face width and body width.

  When there is one person in the shooting area, the AF control unit 49 recognizes the person as a main subject, and in addition to the main subject, a position relatively close to the imaging device 1 (a position where the subject distance is relatively small). If a subject other than a person (for example, a car or a building) exists, the subject is determined to be a sub-subject. Further, when there are two or more persons separated from each other in the shooting area, the AF control unit 49 has a small subject distance because the main subject is often closer to the imaging device 1 than the sub-subject. Since the subject (subject located closer to the imaging device 1) is set as the main subject, and then the main subject is considered to be located closer to the center of the shooting area than the sub subject, Then, the person located closer to the center in the shooting area is set as the main subject.

  In addition, the imaging apparatus 1 of the present embodiment has an FFP mode in which a focus position (focusing point) can be designated. When the focus position is designated in the FFP mode, the main device as described above. Regardless of the subject discrimination method, the subject present at the designated position is set as the main subject, and the other person is set as the sub-subject.

  On the other hand, when performing focus adjustment by the hill-climbing detection method, the AF control unit 49 performs the following processing. FIG. 12 is an explanatory diagram of focus adjustment by the hill-climbing detection method, and shows the relationship between the position of the focus lens 20 in the direction of the optical axis L1 and the contrast of the image obtained by the imaging operation of the imaging device 23.

As shown in FIG. 12, the contrast waveform with respect to the position of the focus lens 20 generally has the highest contrast when the focus lens 20 is positioned at a certain lens position, that is, the captured image is sharpest, and the focus is determined from the lens position. As the lens 20 moves toward the image side and subject side in the direction of the optical axis L1, a mountain-shaped waveform is obtained in which the contrast decreases. FIG. 12 shows that the contrast is maximized when the focus lens 20 is located at the lens position _Xmax when a certain subject is photographed by the imaging apparatus 1.

  The AF control unit 49 divides the entire area or a part of the image after A / D conversion into minute areas, detects the brightness for each area, and determines the difference in brightness between adjacent areas, that is, the contrast. To detect. This process is performed for each captured image while moving the focus lens 20 in the direction of the optical axis L1 to find a position where the contrast is maximum, and the focus lens 20 is positioned at that position.

That is, in FIG. 12, assuming that the focus lens 20 is located at a position X _{1 in the} optical axis direction (hereinafter referred to as a reference position X ₁ ) immediately after the power of the imaging apparatus 1 is turned on, the shutter button 4 is When half-pressed, the AF control unit 49 causes the image sensor 23 to capture a subject image with the focus lens 20 positioned at the position X ₁ and derives the contrast C (X ₁ ) from this image data. Next, the AF control unit 49 moves the focus lens 20 to, for example, the optical axis L1 direction image side by a preset movement pitch Δx, and performs imaging in a state where the focus lens 20 is located at the position X ₂ that is the movement destination. The image of the subject is picked up by the element 23, and the contrast C (X ₂ ) is derived from this image data. At this time, as can be seen from FIG. 12, since C (X ₁ )> C (X ₂ ), the AF control unit 49 does not increase the contrast even if the focus lens 20 is moved from the position X ₁ to the image side. And move from this position X ₂ to the subject side by the movement amount 2Δx (from the reference position X ₁ to the subject side by the movement pitch Δx).

Then, the AF control unit 49 causes the image sensor 23 to capture a subject image in a state where the focus lens 20 is located at the position X ₃ that is the movement destination, and derives the contrast C (X ₃ ) from this image data. At this time, since the contrasts C (X ₁ ) and C (X ₃ ) at the positions X ₁ and X ₃ are C (X ₁ ) <C (X ₃ ) as shown in FIG. control unit 49 determines from the position X ₁ by moving the focus lens 20 on the object side and the contrast is increased, moving further by movement pitch Δx from the position X ₃ of the focusing lens 20 on the object side.

Then, the AF control unit 49 causes the image sensor 23 to capture a subject image in a state where the focus lens 20 is located at the position X ₄ that is the movement destination, and derives the contrast C (X ₄ ) from this image data. At this time, since the magnitudes of C (X ₃ ) and C (X ₄ ) at the positions X ₃ and X ₄ are C (X ₃ ) <C (X ₄ ) as can be seen from FIG. 12, the AF control unit 49 moves the focus lens 20 from the position X ₄ to the subject side by the movement pitch Δx.

Thereafter, similarly, the AF control unit 49 repeatedly performs the derivation of the contrast, and the contrast C (X _n ) at the _nth derived position X _{n and} the contrast at the (n + 1) th derived position X _{n + 1} . When C (X _{n + 1} ) <C (X _n ) is compared with C (X _{n + 1} ), the position X _n is determined as the in-focus position, and the focus lens 20 is moved to the position X _n . Fix it. Thereby, the focus adjustment process by the hill-climbing detection method is completed. When C (X _{n + 1} ) = C (X _n ), it is determined that there is a maximum contrast value between the position X _n and the position X _{n + 1.} For example, the position X _n The focus lens 20 is positioned at an intermediate position between the position X _{n + 1} and the position X _{n + 1} .

  As described above, in the imaging apparatus 1 of the present embodiment having two types of focus adjustment functions, focus adjustment is performed by combining these focus adjustment functions depending on the situation, or focus adjustment is performed by one of the focus adjustment functions alone. It has the feature in the place where it is done.

  That is, the focus adjustment method using the external light passive method can perform the focus adjustment in a short time compared to the focus adjustment using the hill-climbing detection method, but as described above, there is a structural problem (for example, the distance measurement unit 11). Depending on the focal length, the distance measuring unit 11 may not be able to measure the entire area of the image obtained by the imaging optical system 2 and the imaging element 23, depending on the focal length. On the other hand, the focus adjustment method using the hill-climbing detection method has high focus adjustment accuracy and can focus on any subject in the imaging range, but it is more focused than the external light passive method. It takes a long time.

  On the other hand, when the FFP mode is set and the designated focus position (focusing point) is outside the distance measuring area AR2 of the distance measuring unit 11, focus adjustment by the external light passive method cannot be performed at the designated position. .

  Therefore, in the present embodiment, when the FFP mode is set and the designated focus position is within the distance measuring area AR2 of the distance measuring unit 11, the subject distance detected by the distance measuring unit 11 is used to focus roughly. After the adjustment, fine focus adjustment is performed by the hill-climbing detection method (the external light passive method and the hill-climbing detection method are used in combination). In this way, the focus adjustment is performed in a short time compared with the case where the focus adjustment is performed by the hill-climbing detection method alone, and the focus is adjusted with higher accuracy than the case where the focus adjustment is performed by the outside light passive method alone. For example, when the main subject is located outside the distance measuring area AR2 of the distance measuring unit 11, or the main subject is located between subjects imaged by the line sensor of the distance measuring unit 11, for example. Even when the subject measured by the distance measuring unit 11 is not the main subject, the focus adjustment can be reliably performed by performing the focus adjustment by the hill-climbing detection method.

  In addition, when the FFP mode is set, if the designated focus position is outside the distance measuring area AR2 of the distance measuring unit 11, focus adjustment is performed by the hill climbing detection method alone.

  Furthermore, when the FFP mode is not set, when the focus designated position is within the distance measuring area AR2 of the distance measuring unit 11, both focus adjustment methods are used together for the same reason as described above.

  In accordance with this, the AF control unit 49 sets the focus designated position (cursor) determined by re-operation of the push button 7 as shown in FIG. 13A when the FFP mode is not set and when the FFP mode is set. When the position of the CSR is within the distance measurement area AR2 (frame F) of the distance measurement unit 11, pixel data output from the A / D conversion unit 31 after the focus measurement of the passive method by the distance measurement unit 11 is performed. The focus adjustment is performed by the hill-climbing detection method using the contrast of the image constituted by the above.

  However, even if the designated position of the focus is within the distance measurement area AR2 of the distance measuring unit 11, if the subject distance of the subject corresponding to the designated position is equal to or less than the threshold value L, the subject is close to the imaging device 1. The parallax increases, and it is considered that the designated position of the focus is likely to deviate from the distance measurement area AR2 of the distance measurement unit 11. Therefore, the external light passive focus adjustment using the distance measurement unit 11 is not performed, and the imaging range Focus adjustment is performed only by the hill-climbing detection method in which the entire region is the focus adjustment target area.

  Further, as shown in FIG. 13B, the AF control unit 49 causes the designated focus position determined by operating the push button 7 to be outside the distance measurement area AR2 of the distance measurement unit 11 when the FFP mode is set. In some cases, focus adjustment is performed by the hill-climbing detection method alone.

  Note that it is determined whether or not the designated focus position is within the distance measuring area AR2 of the distance measuring unit 11, and the designated focus position when the designated focus position is within the distance measuring area AR2 of the distance measuring unit 11. The block corresponding to is determined using the subject distance and the focal length.

  In other words, when the focus designated position is fixed, if the focal length is varied, the subject corresponding to the designated focus position changes, while the subject to be measured by the distance measuring unit 11 does not change. The correspondence relationship between the designated focus position (the position of the cursor CSR) and the blocks set in the line sensors L1 to L14 in the distance measuring unit 11 changes according to the focal length. Further, as can be seen from FIG. 6, since the distance measurement area AR2 of the distance measurement unit 11 with respect to the imaging range of the imaging optical system 2 changes (moves up and down) according to the subject distance, the above-described correspondence relationship is the subject distance. It also changes depending on. As described above, the correspondence between the designated focus position and the block set in the distance measuring unit 11 changes using the subject distance and the focal length as parameters.

  Therefore, the case where the photographing lens is located on the widest angle side and the subject is present at the subject distance corresponding to the intersection P between the optical axes La and Lb of the distance measuring unit 11 and the optical axis L1 of the imaging optical system 2 is used as a reference. The above-described determination can be made from the relationship between the reference subject distance and focal length and the actual subject distance and focal length (when imaging). The AF control unit 49 corresponds to an evaluation unit, first and second control units, and a switching unit in the claims.

  Returning to FIG. 8, the display control unit 50 transfers the image data of these images to the VRAMs 32 and 33 in order to display the live view image and the recorded image stored in the image storage unit 35 when the shooting mode is set. At the same time, when the playback mode is set, the image data in the image file stored in the image storage unit 35 is read and subjected to a predetermined expansion process, and the image indicated by the image data is reproduced and displayed on the display screen of the LCD 5. The image data is transferred to the VRAM 32.

  When the FFP mode is set, the display control unit 50 superimposes the cross-shaped cursor CSR and the frame F indicating the distance measurement area AR2 of the distance measurement unit 11 on the display image as shown in FIG. And the display position of the cursor CSR is changed according to the operation of the cross operation unit 6.

  14 and 15 are flowcharts showing a series of processing of the imaging apparatus 1. In addition, although the imaging device 1 of this embodiment can display an image on both LCD5 and EVF9, it shall display an image only on LCD5 here.

  As shown in FIG. 14, when the power of the imaging apparatus 1 is turned on (YES in step # 1), the main control unit 46 determines whether or not the photographing mode is set (step # 2). When the playback mode is set (NO in step # 2), the main control unit 46 performs a process of playing back and displaying the image stored in the image storage unit 35 on the LCD 5 (step # 3), and enters the shooting mode. When it is set (YES in step # 2), the display control unit 50 displays on the LCD 5 an image obtained by the image pickup operation of the image pickup device 23 performed on the image pickup device 23 at a predetermined cycle (for example, 1/30 second). It is displayed as a view image (step # 4).

  The AF control unit 49 determines whether or not the FFP mode has been set by the push button 7 until the shutter button 4 is half-pressed (NO in steps # 5 and # 6). When the push button 7 is not set to the FFP mode (NO in step # 5) and the shutter button 4 is half-pressed (YES in step # 6), the main control unit 46 performs the photometry operation on the photometry unit 9. (Step # 7).

  Further, the AF control unit 49 causes the distance measuring unit 11 to perform a distance measuring operation to detect the distance to the subject (steps # 8 and # 9). Here, the main subject detection process as described above is not performed, and the subject distance of the main subject is detected on the assumption that the main subject exists in the center of the shooting range. Then, the display control unit 50 displays an unillustrated mark representing the distance measuring point superimposed on the live view image on the display screen of the LCD 5 in order to indicate the set distance measuring point (here, the center position) (step S40). # 10). The AF control unit 49 drives the focus lens 20 to the lens position corresponding to the distance measurement value (step # 11), and then performs focus adjustment by the hill-climbing detection method (step # 12). As described above, by using the external light passive method using the distance measuring unit 11 and the hill-climbing detection method in combination, it is possible to perform focus adjustment that balances time and accuracy.

  The main control unit 46 and the like repeatedly perform the processing from step # 6 to # 12 until the shutter button 4 is fully pressed (NO in step # 13), and the shutter button 4 is fully pressed. If this is the case (YES in step # 13), an image pickup operation is performed on the image sensor 23 with the exposure control value derived by photometry in step # 7 with the focus lens 20 positioned at the position set in step # 12. The image obtained by the imaging operation is stored in the image storage unit 35 (step # 14).

  Then, the main control unit 46 and the like repeatedly perform the processing from step # 2 to # 14 until the power of the imaging apparatus 1 is turned off (NO in step # 15), and when the power is turned off (step # 15). And YES), a series of processing ends.

  On the other hand, when the FFP mode is set by push button 7 in step # 5 (YES in step # 5), display control unit 50 displays cursor CSR, frame F, and the like on the display screen of LCD 5, as shown in FIG. Is superimposed on the live view image and displayed (step # 16). When the cross operation unit 6 is operated (YES in step # 17), the display position of the cursor CSR is changed in the direction corresponding to the operation (step # 18), and when the cross operation unit 6 is not operated (step # 18). In step # 17, NO), the cursor CSR is displayed at a fixed position.

  Until the push button 7 is pressed again (NO in step # 19), the processes of steps # 17 and # 18 are repeated, and when the push button 7 is pressed again (step # 19). If YES in # 19), the AF control unit 49 changes the cursor CSR position in step # 16 if the cursor CSR position is not changed in step # 17, and changes the cursor position in step # 17. If it is determined, it is determined whether or not the position of the previous cursor CSR changed in step # 18 is within the distance measuring area AR2 of the distance measuring unit 11 (step # 20).

  As a result, when the position of the cursor CSR is within the distance measuring area AR2 of the distance measuring unit 11 (YES in step # 20), the AF control unit 49 reaches the subject in the predetermined area including the position of the cursor CSR. The distance is detected using the distance measuring unit 11 (step # 21). Then, the AF control unit 49 determines whether or not the detected subject distance is greater than a predetermined threshold L (step # 22), and when the subject distance is greater than the threshold L (YES in step # 22), the focus The lens 20 is driven to the lens position corresponding to the subject distance (step # 23).

  Then, the AF control unit 49 repeats the processes of steps # 17 to # 23 until the half-pressing operation of the shutter button 4 is performed (NO in step # 24), and the half-pressing operation of the shutter button 4 is performed. (YES in step # 24), until the full press operation of the shutter button 4 is performed (NO in step # 27), the main control unit 46 causes the photometry unit 9 to perform a photometric operation (step # 25), and the step Focus adjustment by the hill-climbing detection method is performed using the image of the subject corresponding to the position of the cursor CSR set at # 16 or # 18 (step # 26). When the shutter button 4 is fully pressed (YES in step # 27), the exposure derived by photometry in step # 25 with the focus lens 20 positioned at the position set in step # 26. The image sensor 23 is caused to perform an imaging operation with the control value, and an image obtained by the imaging operation is stored in the image storage unit 35 (step # 28).

  In step # 20, when the position of the cursor CSR is outside the distance measurement area AR2 of the distance measurement unit 11 (NO in step # 20), the AF control unit 49 sets the cursor CSR set in step # 18. Focus adjustment by the hill-climbing detection method is performed using the image of the subject corresponding to the position (step # 29). Even when the detected subject distance is equal to or smaller than the predetermined threshold L in step # 22 (NO in step # 22), the AF control unit 49 does not perform focus adjustment using the distance measuring unit 11, Only focus adjustment of the hill-climbing detection method using the image of the subject corresponding to the position of the cursor CSR set in step # 16 or # 18 is performed (step # 29). This is because, when the position of the subject is close to the imaging device 1, the above-described parallax increases, so that there is a high possibility that the designated focus position will be out of the distance measurement area AR2 of the distance measurement unit 11.

  When the shutter button 4 is half-pressed (YES at step # 30), the main controller 46 instructs the photometry unit 9 until the shutter button 4 is fully pressed (NO at step # 32). When the photometry operation is performed (step # 31) and the shutter button 4 is fully pressed (YES in step # 32), the step is performed with the focus lens 20 positioned at the position set in step # 29. The imaging device 23 is caused to perform an imaging operation with the exposure control value derived by the photometry of # 31, and an image obtained by the imaging operation is stored in the image storage unit 35 (step # 28). If it is determined in step # 30 that the shutter button 4 is not half-pressed (NO in step # 30), the process returns to step # 17.

  The main control unit 46 and the like repeatedly perform the processing from step # 2 to # 32 until the power of the imaging apparatus 1 is turned off (NO in step # 33), and when the power is turned off (step # 33). And YES), a series of processing ends.

  As described above, when the FFP mode is set, the designated position is measured by the distance measuring unit 11 in a state where the subject corresponding to the designated position (focus point) of the focus is separated from the imaging device 1 by the distance L. When set in the distance area AR2, since the focus adjustment of the external light passive method using the distance measuring unit 11 and the focus adjustment of the hill climbing detection method are used together, either the external light passive method or the hill climbing detection method is used. On the other hand, as compared with the case where the focus adjustment is performed alone, the focus adjustment in which the accuracy and time of the focus adjustment are compatible can be performed. The same effect can be obtained by performing the same operation even when the FFP mode is not set.

  Further, when the FFP mode is set, the designated focus position is set outside the distance measuring area AR2 of the distance measuring unit 11, and the designated focus position is within the distance measuring area AR2 of the distance measuring unit 11. However, when the subject distance of the subject corresponding to the designated position is equal to or less than the threshold value L, the outside light passive focus adjustment using the distance measuring unit 11 is not performed, and the mountain climbing is performed with the entire imaging range as the focus adjustment target region. By performing focus adjustment only by the detection method, accurate focus adjustment can be performed.

  In addition to the first embodiment, or in place of the first embodiment, the present invention can employ modified embodiments described in the following embodiments (1) to (9).

  (1) In the first embodiment, as shown in step # 22 of FIG. 15, when the FFP mode is set, the external light passive method using the distance measuring unit 11 and the hill-climbing detection method are used in combination. The focus adjustment method or the hill-climbing detection method alone focus adjustment method is changed according to the distance measurement value (subject distance), but instead of or in addition to this, the focal length is small or large The focus adjustment method may be changed according to the above.

  That is, when the zoom lens 19 is driven from the wide angle side to the telephoto side, the imaging range of the image sensor 23 becomes narrow, while the ranging area AR2 of the ranging unit 11 with respect to the imaging range changes according to the focal length. As described above, the distance measurement area AR2 of the distance measurement unit 11 is relatively large with respect to the imaging range of the image sensor 23 because the distance measurement area AR2 of the distance measurement unit 11 is constant (see FIGS. 5 and 7). ).

  Therefore, when the zoom lens 19 is driven from the wide-angle side to the telephoto side, as shown in FIG. 16, the interval H between the subjects imaged by the line sensors L1 to L14 of the distance measuring unit 11 increases. Thus, when the interval H is increased, the designated position of the focus determined by the push button 7 is often set to the gap H between the subjects imaged by the line sensors L1 to L14. When the designated position is set to the gap H, the external light passive type focus adjustment by the distance measuring unit 11 cannot be performed.

  Therefore, when it is considered that there is a high possibility that the designated focus position is set to the gap H, that is, when the focal length is larger than a predetermined threshold value, the external light passive focus adjustment by the distance measuring unit 11 is performed. It is preferable to perform focus adjustment by the hill-climbing detection method without performing the above.

  When the imaging apparatus 1 is equipped with a function for executing this processing, a routine for determining whether or not the focal length at that time is smaller than the threshold value f between steps # 20 and # 21 in FIG. It is preferable that the process of step # 21 is executed when the focal distance is smaller than the threshold f, and the process of step # 29 is executed when the focal distance is greater than or equal to the threshold f.

  In addition, an electronic zoom function (a part of an image obtained by the imaging operation of the imaging device 23 is extracted (trimmed) in the imaging device 1, and the extracted image is enlarged and displayed on the entire display screen such as the LCD 5. If the predetermined electronic zoom magnification is exceeded for the same reason as described above, the outside light passive focus adjustment is not performed by the distance measuring unit 11 and the hill-climbing detection method is used. It is recommended to adjust the focus.

  (2) In the first embodiment, when the focus designated position (the position of the cursor CSR) is outside the distance measuring area AR2 of the distance measuring unit 11, only the focus adjustment by the hill-climbing detection method is performed. Instead of this form, if it is a principle to perform focus adjustment that balances the focus adjustment time and the focus adjustment accuracy, it is prohibited to change the position of the cursor CSR outside the distance measurement area AR2 of the distance measurement unit 11. The position change of the cursor CSR may be permitted only within the distance measuring area AR2 of the distance measuring unit 11.

  FIG. 17 is a flowchart showing a series of processes in the imaging apparatus 1 of the present embodiment. In the present embodiment, as in the first embodiment, the processing in steps # 1 to # 15 in FIG. 14 is performed. On the other hand, the processing when the FFP mode is set is performed in the first embodiment. Since it is different from the form, only processing different from the first embodiment will be described with reference to FIG.

  As shown in FIG. 17, when the FFP mode is set by the push button 7 (YES in step # 5, see FIG. 14), the display control unit 50 displays the cursor CSR and the frame F on the display screen of the LCD 5 as a live view image. (Step # 40). When the cross operation unit 6 is not operated (NO in step # 41), the cursor CSR is displayed at a fixed position. When the cross operation unit 6 is operated (YES in step # 41), the main control is performed. The unit 46 determines whether or not the current position of the cursor CSR is located at the end of the distance measurement area AR2 (step # 42).

  If the position of the cursor CSR is not located at the end of the distance measuring area AR2 (NO in step # 42), the display position of the cursor CSR is changed in the direction corresponding to the operation (step # 43). When the position of the cursor CSR is located at the end of the distance measuring area AR2 (YES in step # 42), the main control unit 46 (corresponding to the prohibiting means in the claims) further outwards. The movement of the cursor CSR is prohibited, and the display control unit 50 causes the cursor CSR to blink to notify that fact (step # 44). After the processing of step # 41 or # 44, the main control unit 46 determines whether or not the push button 7 has been operated again (step # 45), and until the push button 7 is operated again (NO in step # 45). ) Steps # 41 to # 44 are repeated.

  When the push button 7 is operated again (YES in step # 45), the distance measuring unit 11 moves to a subject in a predetermined area including the position of the cursor CSR set in step # 40 or # 43 or # 44. The distance is detected (step # 46), and the AF control unit 49 drives the focus lens 20 to the lens position corresponding to the subject distance (step # 47).

  The main control unit 46 repeats the processes from step # 41 to # 47 until the shutter button 4 is half-pressed (NO in step # 48), and when the shutter button 4 is half-pressed (step # 48). Until the shutter button 4 is fully pressed (NO in step # 51) until the shutter button 4 is fully pressed (NO in step # 48), the main control unit 46 causes the photometry unit 9 to perform a photometric operation (step # 49), and the AF control unit In step # 40, focus adjustment is performed by the hill-climbing detection method using the image of the subject corresponding to the position of the cursor CSR set in step # 40 or # 43 or # 44 (step # 50).

  When the shutter button 4 is fully pressed (YES in step # 51), the exposure derived by photometry in step # 49 with the focus lens 20 positioned at the position set in step # 50. The imaging device 23 is caused to perform an imaging operation with the control value, and an image obtained by the imaging operation is stored in the image storage unit 35 (step # 52).

  When the power of the imaging device 1 is not turned off (NO at step # 53), the main control unit 46 and the like return to the process at step # 2 of FIG. 14 and when the power is turned off (YES at step # 53). ), A series of processing ends.

  (3) In the modification (2), when the position of the cursor CSR is located at the end of the distance measurement area AR2, to notify that the cursor CSR is not allowed to move further outside, Although the cursor CSR is displayed in a blinking manner, the present invention is not limited to this, and the fact may be notified by changing the display color of the cursor CSR or outputting a sound. Moreover, the form which alert | reports combining these may be sufficient.

  (4) In the first embodiment, when the FFP mode is set, when the focus designated position (the position of the cursor CSR) is outside the distance measuring area AR2 of the distance measuring unit 11, the hill climbing detection method alone The focus adjustment is performed in the above. However, when the FFP mode is set, when it is thought that focusing on the position designated as the focus position should be given the highest priority, the focus designated position (the position of the cursor CSR) Regardless of whether or not is within the distance measuring area AR2 of the distance measuring unit 11 or outside the distance measuring area AR2, when the FFP mode is set, focus adjustment may always be performed by the hill-climbing detection method alone.

  FIG. 18 is a flowchart showing a series of processes in the imaging apparatus 1 of the present embodiment. In the present embodiment, as in the first embodiment, the processing in steps # 1 to # 15 in FIG. 14 is performed. On the other hand, the processing when the FFP mode is set is performed in the first embodiment. Since it is different from the form, only processing different from the first embodiment will be described with reference to FIG.

  As shown in FIG. 18, when the FFP mode is set by the push button 7 (YES in step # 5, see FIG. 14), the display control unit 50 superimposes the cursor CSR on the live view image on the display screen of the LCD 5. Display (step # 60). In this step # 40, the frame F may also be displayed on the LCD 5, but in this embodiment, focus adjustment is performed by the hill-climbing detection method alone regardless of the position of the cursor CSR. Since no special effect is obtained, the frame F is not displayed on the LCD 5.

  When the cross operation unit 6 is not operated (NO in step # 61), the display control unit 50 displays the cursor CSR at a fixed position, and when the cross operation unit 6 is operated (step # 61). YES), the display position of the cursor CSR is changed in the direction corresponding to the operation (step # 62). The main control unit 46 and the like repeat the processes of steps # 61 and # 62 until the push button 7 is pressed again (NO in step # 63), and the push button 7 is pressed again. When it is performed (YES in step # 63), the AF control unit 49 performs focus adjustment by the hill-climbing detection method using the image of the subject corresponding to the position of the cursor CSR set in step # 60 or # 62 ( Step # 64).

  Then, the AF control unit 49 repeatedly performs the processes from step # 61 to # 64 until the shutter button 4 is half-pressed (NO in step # 65). When the half-press operation of the shutter button 4 is performed (YES in step # 65), the main control unit 46 instructs the photometry unit 9 until the full-press operation of the shutter button 4 is performed (NO in step # 67). When the photometry operation is performed (step # 66) and the shutter button 4 is fully pressed (YES in step # 67), the step is performed with the focus lens 20 positioned at the position set in step # 64. The imaging device 23 is caused to perform an imaging operation with the exposure control value derived by the photometry of # 66, and an image obtained by the imaging operation is stored in the image storage unit 35 (step # 68).

  When the power of the imaging device 1 is not turned off (NO at step # 69), the main control unit 46 and the like return to the process at step # 2 of FIG. 14 and when the power is turned off (YES at step # 69). ), A series of processing ends.

  (5) Although the cursor CSR and the frame F are displayed when the FFP mode is set in the first embodiment and the modification (2), the frame F is not necessarily displayed.

  (6) In the hill-climbing detection method, the position of the focus lens 20 is determined based on the contrast of the image. However, the present invention is not limited to this, and the position of the focus lens 20 is determined based on the spatial frequency of the image. May be.

  (7) The operation means for changing the display position of the cursor CSR is not limited to the configuration having the pressing portions 4a to 4d and the corresponding contacts provided as described above. It is also possible to have a configuration that includes a lever that can swing 360 ° with a detecting point as a fulcrum, and a detector that detects the tilt direction of the lever.

  (8) The ranging sensor unit 16 of the ranging unit 11 is configured by a plurality of line sensors (L1 to L14), but is not limited thereto, and may be configured by, for example, an area sensor. In this case, the present invention is applied similarly to the first embodiment by regarding the area sensor as a plurality of line sensors extending in the X direction shown in FIG. 4 and arranged adjacent to each other in the Y axis direction. be able to.

  (9) In the first embodiment, the photometric unit 10 is provided to detect the subject luminance. However, the photometric unit 10 is not provided, and the subject luminance is determined based on the outputs of the distance measuring unit 11 and the image sensor 23. The exposure control value may be determined based on the detected object brightness.

  The imaging apparatus 1 described above includes the inventions shown in the following supplementary notes 1 to 3 in addition to those described in the claims.

[Supplementary Note 1] An image display unit that displays an image obtained by the output of the imaging unit;
And a display control unit configured to superimpose and display a range that can be measured by the ranging unit on an image displayed on the image display unit when the manual focusing mode setting mode is set. Item 5. The imaging device according to any one of Items 1 to 4.

  According to the present invention, when the in-focus manual setting mode is set, the range that can be measured by the distance measuring unit is displayed superimposed on the image displayed on the image display unit. The range in which the distance can be measured can be visually confirmed.

  [Supplementary Note 2] The imaging apparatus according to claim 6, further comprising a notification unit configured to notify a prohibition state by the prohibition unit.

  According to the present invention, since the prohibition state by the prohibition unit is notified, the position specified as the focal point by the operation unit is prohibited from being set in the range where the distance measurement unit cannot measure the distance. Can be recognized by the user of the imaging apparatus.

  [Supplementary Note 3] The display control unit displays an index indicating a position designated as a focal point by the operation unit so as to be superimposed on an image displayed on the image display unit, and can be measured by the ranging unit. It is characterized in that the prohibition state by the prohibiting means is notified by changing the display form of the indicator depending on whether it is located at the end of the range or at a position other than the end within the range. The imaging apparatus according to Appendix 2.

  According to the present invention, the prohibited state can be visually recognized.

It is a front view which shows the structure of the imaging device which concerns on this invention. It is a rear view of an imaging device similarly. (A) is a figure which shows the cursor displayed superimposed on an image on the display screen of LCD or EVF, (b) is a figure which shows a mode that the cursor moves. (A) is sectional drawing which shows the internal structure of a ranging part, (b) is a figure which shows the structure of the ranging sensor part in a ranging part when it sees from the arrow Q in (a). It is a figure which shows the relationship between an imaging range and the ranging area of a ranging part when a zoom lens is located in a wide end position. It is the figure which showed the relationship between the imaging | photography area | region when a zoom lens is located in a wide end position and a tele end position, and the ranging area of a ranging part. FIG. 6 is a diagram illustrating a relationship among an imaging range, a distance measurement unit, and a distance measurement area when the zoom lens is driven from the wide angle side to the telephoto side from the state illustrated in FIG. 5. It is a block diagram which shows the structure of an imaging device. It is a figure for demonstrating the principle of the ranging calculation by an external light passive system (triangular ranging system). It is a figure for demonstrating the principle of the ranging calculation by an external light passive system (triangular ranging system) similarly. It is a figure for demonstrating the principle of the ranging calculation by an external light passive system (triangular ranging system) similarly. It is a figure which shows the relationship between the position of the focus lens in an optical axis direction, and contrast. (A) shows the state where the cursor is set within the distance measuring area of the distance measuring unit, and (b) shows the state where the cursor is set outside the distance measuring area of the distance measuring unit. It is a flowchart which shows a series of processes of an imaging device. It is a flowchart which similarly shows a series of processes of an imaging device. FIG. 5 is a diagram illustrating a state in which the zoom lens is driven from the wide-angle side to the telephoto side to increase the interval between the subjects imaged by the line sensors of the distance measuring unit, and the cursor is set in the gap. It is a flowchart which shows another series of processes in an imaging device. It is a flowchart which shows another series of processes in an imaging device.

Explanation of symbols

2 Imaging optical system 5 LCD
6 Cross control unit (operation means)
7 Push button (operation means)
9 EVF
11 Ranging section (ranging means)
14, 15 Ranging optical system 16 Ranging sensor units 17, 18 Line sensor groups L1 to L14 Line sensor 19 Zoom lens 20 Focus lens (focus adjusting means)
L1, La, Lb Optical axis 23 Imaging element (imaging means)
48 Mode setting section (mode setting means)
49 AF control section (evaluation means, first control means, second control means, switching means)
50 Display controller

Claims (6)

Imaging means for photoelectrically converting a light image of a subject;
An imaging optical system that includes a focus adjustment unit for focusing the focal position of the imaging lens on the imaging surface of the imaging unit, and forms a subject image on the imaging surface of the imaging unit;
Evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means;
A pair of distance measuring optical systems, and an external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to each distance measuring optical system and having a plurality of distance measuring points;
A mode setting means for setting to an in-focus manual setting mode capable of inputting an in-focus point from the imaging area of the imaging means;
An operation means for performing input for designating a focal point;
First control means for causing the focus adjustment means to perform a focusing operation using the evaluation by the evaluation means;
Second control means for causing the focus adjusting means to perform a focusing operation using the subject distance detected by the distance measuring means and the evaluation by the evaluating means;
Switching means for switching between the control by the first control means and the control by the second control means in accordance with the position designated as the focus by the operating means when the in-focus manual setting mode is set; An imaging apparatus comprising:   The second control unit causes the focus adjustment unit to perform a focusing operation using the subject distance detected by the distance measurement unit, and then focuses the focus adjustment unit using the evaluation by the evaluation unit. The imaging apparatus according to claim 1, wherein an operation is performed.   The switching means is set to control by the second control means when the position designated as the focal point by the operation means is within the distance measuring range of the distance measuring means, and the distance measuring means of the distance measuring means is set. 3. The image pickup apparatus according to claim 1, wherein when it is out of a possible range, the control by the first control means is set.   2. When the subject distance is smaller than a predetermined threshold value, the switching means sets the control by the first control means regardless of the position designated as the focal point by the operation means. 4. The imaging device according to any one of 3 to 3. Imaging means for photoelectrically converting a light image of a subject;
An imaging optical system that includes a focus adjustment unit for focusing the focal position of the imaging lens on the imaging surface of the imaging unit, and forms a subject image on the imaging surface of the imaging unit;
Evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means;
A pair of distance measuring optical systems, and an external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to each distance measuring optical system and having a plurality of distance measuring points;
A mode setting means for setting to an in-focus manual setting mode capable of inputting an in-focus point from the imaging area of the imaging means;
An operation means for performing input for designating a focal point;
First control means for causing the focus adjustment means to perform a focusing operation using the evaluation by the evaluation means;
Second control means for causing the focus adjusting means to perform a focusing operation using the subject distance detected by the distance measuring means and the evaluation by the evaluating means;
A prohibiting unit for prohibiting the position designated by the operating unit from being set as a focal point when the manual focusing point manual setting mode is set;
An image pickup apparatus comprising: a setting unit configured to set control by the first control unit when the setting is prohibited by the prohibiting unit. Imaging means for photoelectrically converting a light image of a subject;
An imaging optical system that includes a focus adjustment unit for focusing the focal position of the imaging lens on the imaging surface of the imaging unit, and forms a subject image on the imaging surface of the imaging unit;
Evaluation means for evaluating the clarity of an image obtained by the imaging operation of the imaging means;
A pair of distance measuring optical systems, and an external light passive type distance measuring means provided with a plurality of distance measuring sensors provided corresponding to each distance measuring optical system and having a plurality of distance measuring points;
A mode setting means for setting to an in-focus manual setting mode capable of inputting an in-focus point from the imaging area of the imaging means;
An operation means for performing input for designating a focal point;
First control means for causing the focus adjustment means to perform a focusing operation using the evaluation by the evaluation means;
Second control means for causing the focus adjusting means to perform a focusing operation using the subject distance detected by the distance measuring means and the evaluation by the evaluating means;
An imaging apparatus comprising: setting means for setting control by the first control means when the in-focus manual setting mode is set.

Images