JP2011022499A - Autofocus system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an autofocus system including an automatic AF frame tracking function, which enables an operator (cameraman or camerawoman) to instantaneously determine an operation state of the automatic AF frame tracking function while looking in a viewfinder, and also enables the operator to easily know an operation mode of the automatic AF frame tracking function selected at present. <P>SOLUTION: In the autofocus system including the automatic AF frame tracking function, a lens device 12 outputs information showing whether the automatic AF frame tracking function normally operates, and automatic AF frame tracking information including the operation mode of an automatic AF frame tracking means to a camera body 14 to thereby display the automatic AF frame tracking information on the viewfinder 36. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an autofocus system, and more particularly to an autofocus system having an AF frame automatic tracking function.

  Conventionally, for example, when shooting a scene where the subject is moving rapidly, such as in a sports broadcast, with a TV camera or the like, an AF frame auto-tracking function that automatically tracks the subject with an autofocus area (AF area) for the purpose of focusing on the subject An equipped autofocus system is known. In this specification, the term “AF frame” indicating the outline of the range of the AF area is mainly used as a term meaning the range of the subject to be focused in the same manner as the AF area.

  For example, Patent Document 1 includes a viewfinder that displays a captured image of a camera, and the viewfinder can distinguish between when the AF frame automatic tracking function is operating normally and when it is not operating normally. Describes an autofocus system in which an AF frame is displayed in a different manner. According to this autofocus system, it is possible to instantaneously determine whether or not the AF frame automatic tracking function is operating normally by a viewfinder in which the cameraman is constantly watching.

JP 2006-258943 A

  Meanwhile, some conventional autofocus systems have a plurality of operation modes as an AF frame automatic tracking function. As a plurality of operation modes, for example, a mode in which the face of a person detected by face detection processing is set as a tracking target to automatically track the AF frame (face detection tracking mode), a subject within the range of the AF frame ( There is a mode (object tracking mode) in which an AF frame is automatically tracked by pattern matching processing with an arbitrary object) as a tracking target.

  In such an autofocus system, a predetermined operation mode is selected from a plurality of operation modes according to the subject to be tracked, and the AF frame is automatically tracked.

  However, in the conventional autofocus system, the operation mode of the AF frame automatic tracking function that is currently selected is not displayed on the viewfinder, and the operator (cameraman) cannot recognize the operation mode instantaneously. As a result, for example, even if the face of a person appears to be tracked, the object tracking mode may actually be selected, and the tracking performance will deteriorate. Occurs. In addition, this failure often results in tracking failure (tracking is impossible).

  In order to solve the above problem, a display device different from the viewfinder may be provided to display the operation mode of the AF frame automatic tracking function on the display device. In order to confirm the operation mode, it is necessary to keep an eye on the viewfinder, which makes the operation complicated and causes a broadcast accident.

  The present invention has been made in view of such circumstances. In an autofocus system having a plurality of operation modes as an AF frame automatic tracking function, the operating state of the AF frame automatic tracking function while an operator looks at the viewfinder. It is an object of the present invention to provide an autofocus system that can instantly determine the operation mode of the currently selected AF frame automatic tracking function.

  In order to achieve the object, an autofocus system according to a first aspect of the present invention includes an imaging unit that captures a subject image formed by an optical system, and a predetermined AF frame among captured images captured by the imaging unit. Auto-focus means for adjusting the focus of the optical system so that the subject in the range is in focus, and an AF frame for automatically tracking the AF frame to the subject to be tracked so that the predetermined subject to be tracked is in focus Automatic tracking means, viewfinder control means for controlling display of a viewfinder that displays a photographed image taken by the imaging means, and AF frame information for displaying the AF frame on the viewfinder. AF frame information output means for outputting to the means, and automatic AF frame tracking by the AF frame automatic tracking means is normally performed. Information indicating whether it is, and is characterized in that and an automatic tracking information output means for the AF frame auto-tracking information and output to the viewfinder control means including an operation mode of the AF frame auto-tracking means.

  According to a second aspect of the present invention, in the invention according to the first aspect, the viewfinder control means changes the display mode of the AF frame based on the AF frame automatic tracking information, and the AF frame automatic tracking means. The operation mode is displayed.

  The autofocus system according to a third aspect is the invention according to the second aspect, wherein the viewfinder control means displays the operation mode of the AF frame automatic tracking means using characters, figures, or symbols. To do.

  According to a fourth aspect of the present invention, there is provided the autofocus system according to the second or third aspect, wherein the viewfinder control means is configured such that the AF frame automatic tracking by the AF frame automatic tracking means is normally performed. The AF frame is displayed in a different manner on the viewfinder so that it can be distinguished from a case where it is not normally performed.

  The autofocus system according to a fifth aspect is the invention according to any one of the first to fourth aspects, wherein the automatic tracking information output means is configured so that the viewfinder control means performs the AF frame automatic tracking information according to the AF frame automatic tracking information. When the function of changing the display mode of the AF frame is not provided, the AF frame automatic tracking information is not output to the viewfinder.

  According to the present invention, it is possible to instantaneously determine whether or not the AF frame automatic tracking function is operating normally in a viewfinder that an operator such as a cameraman is constantly viewing, and the currently selected AF frame. The operation mode of the automatic tracking function can be easily grasped.

1 is an external view showing an embodiment of a television camera system to which the present invention is applied. The block diagram which showed the whole structure of the AF frame automatic tracking system applied to the television camera system of FIG. Illustration of AF frame (AF area) External view of focus demand The figure which showed an example of the screen displayed on a liquid crystal display with a touch panel The figure which showed an example of the aspect which changes the display form of AF frame according to AF frame automatic tracking information

  Hereinafter, an autofocus system according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an external view showing an embodiment of a television camera system to which the present invention is applied. As shown in the figure, a television camera 10 is a television camera mainly used for broadcasting or business use. The television camera 10 includes a lens device 12 and a camera body 14 and is mounted on a pedestal stand 16. It is supported by.

  The pan head 18 is extended with two left and right bread bars 22 and 24, and a focus demand (focus controller) 26 is installed on the grip part 22 </ b> A of the right bread bar 22 with a mounting clamp 38, and the left side A zoom demand (zoom controller) 28 is installed in the grip portion of the pan bar 24.

  The focus demand 26 is provided with a rotatable focus knob 30. When focus control is performed by manual focus (MF), when the focus knob 30 is rotated, a focus corresponding to the rotation position is obtained. A focus control signal for instructing movement of the focus (focus lens) with the position as the target position is given from the focus demand 26 to the lens device 12. As a result, the focus lens of the lens device 12 moves to the target position commanded by the focus control signal.

  The zoom demand 28 is provided with a rotatable thumb ring 34. When the thumb ring 34 is rotated in the left-right direction, the zoom (zoom lens) is moved with a zoom speed corresponding to the rotation position as a target speed. A zoom control signal to be commanded is given from the zoom demand 28 to the lens device 12. As a result, the zoom lens of the lens device 12 moves at the target speed commanded by the zoom control signal.

  Although not shown in the figure, the focus demand 26 is provided with various operation members related to autofocus (AF), and control of an AF frame indicating a subject range (AF target range) to be focused by AF ( An AF frame control device (AF frame automatic tracking device) for performing a change in position and the like is incorporated, and various operation members of the AF frame control device are also provided in the focus demand 26.

  Further, as shown in the figure, a liquid crystal display (LCD) 40 with a touch panel is installed on the upper part of the focus demand 26 as a constituent element of the AF frame control device, and is connected to the focus demand 26 by a cable (not shown).

  In the following description, the LCD 40 is simply referred to as the LCD 40 with a touch panel. The LCD 40 can be installed at any position other than the upper part of the main body of the focus demand 26. For example, it may be installed beside the viewfinder 36.

  A viewfinder 36 that is a display device is installed on the camera body 14. Since the viewfinder 36 displays an image of the subject photographed by the television camera 10, the cameraman operates the focus demand 26 and the zoom demand 28 while viewing the image, thereby selecting the subject with a desired composition. You can shoot. In the following description, the term “captured video” or “captured image” refers to a video or image currently captured by the television camera 10.

  In addition, an image of the AF frame indicating the position, size, and shape (aspect ratio) where the AF frame is currently set is superimposed on the captured image displayed on the viewfinder 36. When focus control is performed by AF, it is possible to know which range of subjects in the captured image can be focused. The focus control of MF and AF can be switched by a mode switch or the like provided in the focus demand 26.

  FIG. 2 is a block diagram showing an overall configuration of an autofocus system applied to the television camera system.

  The autofocus system 1 shown in FIG. 1 shows the lens device 12, the camera body 14, and the viewfinder 36 of the television camera 10 shown in FIG. 1. Further, as components of the focus demand 26 in FIG. 1, a focus operation unit 50, an image processing unit 58 and an AF frame operation unit 60 constituting an AF frame control device (AF frame automatic tracking device) incorporated in the focus demand 26. It is shown.

  The television camera 10 includes a camera body 14 composed of an HD camera compatible with a high-definition television [HD (High Definition) TV] system, and a lens device 12 having a photographing lens (optical system) attached to a lens mount of the camera body 14. It consists of.

  The camera body 14 is equipped with an image sensor (for example, a CCD), a required signal processing circuit, and the like. The image formed by the photographing lens of the lens device 12 is photoelectrically converted by the image sensor and then subjected to signal processing. Necessary signal processing is performed by the circuit and output as an HDTV video signal (HDTV signal) from the video signal output terminal of the camera body 14 to the outside.

  In addition, as shown in FIG. 1, a video captured by the television camera 10 is displayed on the viewfinder 36 installed on the upper part of the camera body 14 or the like. Various information other than the captured video is displayed on the viewfinder 36. For example, an image indicating the currently set AF frame range (position, size, shape) is superimposed on the captured video. Has been displayed.

  The lens device 12 includes a photographic lens (zoom lens) 64 attached to a lens mount of the camera body 14, and the subject 56 forms an image on the imaging surface of the image sensor of the camera body 14 by the photographic lens 64. It is like that. Although not shown, the photographing lens 64 is provided with movable parts for adjusting photographing conditions such as a focus lens group, a zoom lens group, and a diaphragm as its constituent elements. Servo mechanism) is electrically driven. For example, the focus lens group and the zoom lens group move in the optical axis direction, the focus (subject distance) adjustment is performed by moving the focus lens group, and the focal length (zoom magnification) is adjusted by moving the zoom lens group. Adjustments are made.

  In the AF-related system, it is sufficient that at least the focus lens group can be driven electrically, and other movable parts may be driven only manually.

  The lens device 12 includes an AF unit 66 and a lens CPU (not shown). The lens CPU controls the entire lens device 12 and controls the state (position, speed) of a control target that is electrically driven by a motor such as a focus lens group, a zoom lens group, and a diaphragm by driving the motor. The AF unit 66 is a processing unit for acquiring information necessary for performing AF focus control (automatic focus adjustment), and is configured from an AF processing unit, an AF imaging circuit, and the like, although not shown. Has been.

  The AF imaging circuit is disposed in the lens device 12 to acquire an AF processing video signal, and an output signal from an imaging device such as a CCD (referred to as an AF imaging device) or an AF imaging device is output in a predetermined format. A processing circuit for outputting as a signal is provided. The video signal output from the AF imaging circuit is a luminance signal.

  On the imaging surface of the AF imaging device, subject light branched from subject light incident on the imaging device of the camera body 14 is imaged by a half mirror or the like disposed on the optical path of the photographing lens 64. . The shooting range and subject distance (distance of the subject in focus) with respect to the imaging area of the AF imaging element are configured to match the shooting range and subject distance with respect to the imaging area of the imaging element of the camera body 14. The subject image captured by the image sensor coincides with the subject image captured by the image sensor of the camera body 14. It should be noted that the shooting ranges of the two do not need to be completely the same. For example, the shooting range of the AF imaging element may be a larger range including the shooting range of the imaging element of the camera body 14.

  The AF processing unit acquires a video signal from the AF imaging circuit, and based on the video signal, calculates a focus evaluation value indicating the level of contrast of the subject image within an AF area (AF frame) that is an AF target range. calculate. For example, a high frequency component signal is extracted from a video signal obtained from an AF image sensor by a high-pass filter, and then a range corresponding to an AF area set as described later in the high frequency component signal. Are integrated for each screen (one frame). The integrated value obtained for each screen in this manner indicates the level of contrast of the subject image in the AF area, and the integrated value is given to the lens CPU as a focus evaluation value.

  The lens CPU acquires AF frame information (AF frame information) indicating the range (contour) of the AF area from the image processing unit 58 as described later, and the range within the AF frame specified by the AF frame information is obtained. The AF area is designated as the AF area. Then, the focus evaluation value obtained from the image (video signal) in the AF area is acquired from the AF processing unit.

  In this way, every time a video signal for one screen is acquired from the AF imaging circuit (each time the focus evaluation value is obtained by the AF processing unit), the focus evaluation value is acquired from the AF processing unit, and the acquired focus is obtained. The focus lens group is controlled so that the evaluation value is maximum (maximum), that is, the contrast of the subject image in the AF frame is maximum. For example, a hill-climbing method is generally known as a control method for a focus lens group based on a focus evaluation value, and the focus evaluation value starts to decrease by moving the focus lens group in a direction in which the focus evaluation value increases. Is detected, the focus lens group is set at that position. Thereby, the subject in the AF frame is automatically focused.

  Note that the above-described AF processing unit obtains a video signal from the AF image sensor mounted on the lens device 12 in order to calculate the focus evaluation value, but the video imaged by the image sensor of the camera body 14 The video signal may be obtained from the camera body 14. Also, any AF means for automatically focusing on the subject within the AF frame may be used.

  Here, as shown in FIG. 3, the AF area 200 is set as a rectangular area with respect to the imaging area 202 of the imaging device in the camera body 14, and a frame 204 indicating the outline indicates an AF frame, A subject photographed in the range of the AF area 200 (within the AF frame 204) is an object to be focused by AF.

  In this specification, the range of the AF frame 204 (AF area 200) with respect to the imaging area 202 is determined by three factors including the position, size, and shape (aspect ratio) of the AF frame 204. The description of “changing the frame range” means changing at least one of the three elements of the position, size, and shape of the AF frame.

  The lens device 12 is connected to the camera body 14 via a cable or directly, and various kinds of information are transmitted through serial communication interfaces (SCI) 12a and 14a provided in the lens device 12 and the camera body 14, respectively. You can communicate. As a result, information on the AF frame currently set in the AF unit 66 is also transmitted to the camera body 14, and the position of the AF frame currently set in the captured image displayed on the viewfinder 36 by processing in the camera body 14. The image of the AF frame corresponding to the size and shape is superimposed and displayed.

  The focus operation unit 50 is a constituent element of the focus demand 26 and also shows constituent elements of a general focus demand. As the components of the focus operation unit 50, the focus knob 30 shown in FIG. 1, a mode switch (not shown) for switching between the AF mode and the MF mode and switching the AF mode type (continuous mode or momentary mode). And an operation member related to AF control contents and MF control, such as an AF start switch (not shown) for instructing the start of AF, and detecting the setting state of these operation members, and based on the detected setting state A processing circuit for sending control signals is provided.

  The focus demand 26 is provided with an interface (I / F) 52 for connecting to the lens device 12 with a cable. The focus operation unit 50 is connected to the lens device 12 via the I / F 52 and the cable, and the SCI 12a. Various signals can be exchanged through serial communication with the lens CPU.

  Accordingly, various control signals sent from the focus operation unit 50 are given to the lens CPU, and processing according to the control signals is executed by the lens CPU. For example, when an instruction for focus control (AF mode) by AF is given, focus control by AF is performed based on the focus evaluation value obtained from the AF unit 66 as described above, and focus control by MF (MF When an instruction of (mode) is given, focus control by MF is performed according to a focus position command signal given from the focus operation unit 50 based on the operation of the focus knob 30.

  The image processing unit 58 is a processing unit incorporated in the focus demand 26 as a component of the AF frame control device, and the range (position, size, shape (vertical and horizontal) of the AF frame set in the AF unit 66 of the lens device 12. A ratio)) is designated by a manual operation or AF frame automatic tracking process described later.

  The image processing unit 58 includes an SCI 70a. The SCI 70a is connected to the lens apparatus 12 via the I / F 52, and can exchange various signals with the lens CPU through the SCI 12a by serial communication. ing. Thereby, for example, AF frame information for designating the range of the AF frame is given from the image processing unit 58 to the lens CPU of the lens apparatus 12, and the range of the AF frame in the AF unit 66 is set based on the AF frame information. .

  The focus demand 26 is provided with a video input connector for taking a video signal into the image processing unit 58, and the video output connector of the camera body 14 is connected to the video input connector via a down converter 68 with a cable. The As a result, the HDTV signal output from the video output connector of the camera body 14 is converted (down-converted) into a standard television [NTSC (National Television System Committee)] video signal (SDTV signal) by the down converter 68. Are input to the image processing unit 58.

  When executing the AF frame automatic tracking process, the image processing unit 58 sequentially captures one frame of the captured image from the image signal of the captured image input from the camera body 14, and selects a predetermined tracking target from the captured image. The process of detecting the subject is performed. Then, the AF frame range is determined so that the subject can be focused by AF, and the determined AF frame range is transmitted to the lens CPU of the lens device 12.

  The AF frame operation unit 60 is integrally provided with the image processing unit 58 in the focus demand 26 as an AF frame control device, or a part or all of the AF frame operation unit 60 is a separate device from the focus demand 26, that is, image processing. The unit 58 is provided in a separate device and connected by a cable or the like. In the present embodiment, as shown in FIG. 1, the LCD 40 with a touch panel is provided separately from the focus demand 26 (image processing unit 58), and the other components are provided together with the image processing unit 58 on the focus demand 26. .

  The AF frame operation unit 60 is an operation unit for mainly performing operations related to control of the AF frame, and an operation member for an operator to manually input an AF frame range or an AF frame to a desired subject. There is provided an operation member for performing an operation related to AF frame automatic tracking to be automatically tracked.

  As shown in the external view of the focus demand 26 in FIG. 4, as the operation member of the AF frame operation unit 60, a position operation member 100 (for example, for moving the position of the AF frame up and down and left and right manually by the user) , A joystick or a trackball), a size operation member 102 (for example, a knob) for manually changing the size of the AF frame, and a shape operation member 104 (for example, a knob) for changing the shape of the AF frame by manual operation. ), A tracking start switch 108 for instructing start of AF frame automatic tracking, and a tracking stop switch 110 for instructing stop of AF frame automatic tracking are provided. Setting of these operation members 100, 102, 104, 108, 110 is provided. The state is read by the image processing unit 58 (CPU 78 of the main board 70 described later).

  Further, the LCD 40 of the AF frame operation unit 60 is configured such that settings such as a mode related to AF frame automatic tracking can be input by a touch operation (tap operation), and an image displayed on the LCD 40 by the CPU 78 of the image processing unit 58 is displayed. It can be switched appropriately according to the setting contents.

  In the present embodiment, the AF frame control device including the image processing unit 58 and the AF frame operation unit 60 is incorporated in the focus demand 26. However, the AF frame control device is different from the focus demand 26. It may be configured as a body device. In this case, a part or all of the AF frame operation unit 60 may be provided in an apparatus integrated with the image processing unit 58, or may be provided in a separate apparatus.

  Next, the configuration and processing contents of the image processing unit 58 will be described.

  The image processing unit 58 mainly includes a main board 70, a pattern matching processing calculation board 72, and a face recognition processing calculation board 74. Each of the main board 70, the pattern matching processing calculation board 72, and the face recognition processing calculation board 74 is equipped with CPUs 78, 90, and 92. Individual calculation processing is performed for each board, and each of the CPUs 78, 90, Reference numerals 92 are connected by a bus or a control line so that data can be exchanged or arithmetic processing can be synchronized with each other.

  The processing in the image processing unit 58 is performed on the main board 70 in an integrated manner. In addition to the CPU 78 that performs arithmetic processing, the main board 70 is equipped with an SCI 70a, a decoder (A / D converter) 76, a superimposer 82, a RAM 80, and the like.

  The SCI 70 a is an interface circuit for performing serial communication with the SCI 12 a of the lens device 12 as described above, and transmits the AF frame information and the like to the lens device 12.

  The decoder 76 is a circuit for converting a video signal (SDTV signal) of a video image taken by the television camera 10 input from the down converter 68 to the image processing unit 58 into data that can be digitally processed by the image processing unit 58. A / D conversion processing for converting an analog SDTV signal into a video signal of digital data is performed. The video signal of the captured video output from the decoder 76 is also sent to the pattern matching processing calculation board 72 and the face recognition processing calculation board 74, and the television camera 10 is also used in the pattern matching processing calculation board 72 and the face recognition processing calculation board 74. The captured video can be acquired as a captured image for each frame.

  The superimposer 82 is a circuit that synthesizes the video signal of the captured video obtained by the decoder 76 and the image signal generated by the CPU 78 and outputs and displays the synthesized video signal on the LCD 40. As a result, the image captured by the television camera 10 is displayed on the LCD 40 in the same manner as the viewfinder 36 installed in the camera body 14, and the AF indicating the currently set AF frame range is superimposed on the image captured. An image of the frame, a menu screen (menu image) that allows input operations on the touch panel, and the like are displayed on the LCD 40. Of course, it is also possible to display only the image generated by the CPU 78 without being superimposed on the captured video.

  The RAM 80 is a memory that temporarily stores data used in the arithmetic processing of the CPU 78.

  On the other hand, the pattern matching processing calculation board 72 and the face recognition processing calculation board 74 are calculation boards for individually performing pattern matching and face detection / recognition processing. In addition to the CPUs 90 and 92 that perform calculation processing, image data VRAM 94, 96, etc. are temporarily stored.

  Further, the image processing unit 58 is provided with a slot 115 into which a data card 114 is loaded as an external memory such as an SD (Secure Digital) card or a USB memory, and when detecting a face of a specific person by face recognition. Authentication data indicating the face of the specific person is stored in the data card 114 in advance, and the data card 114 is loaded into the slot 75, whereby the CPU 78 can read the authentication data necessary for face recognition from the data card 114. It is like that.

  Subsequently, control of the AF frame by the image processing unit 58 configured as described above will be described together with processing relating to display and operation of the LCD 40.

  As shown in FIG. 5, on the screen 40a of the LCD 40, a menu screen (menu image) composed of various buttons 300 to 310 superimposed on the video image taken by the TV camera 10, and an AF indicating the currently set AF frame range. A frame image 204 (simply referred to as AF frame 204) is displayed. Images to be superimposed on the captured video, such as the various buttons 300 to 310 on the menu screen and the AF frame 204, are generated by the CPU 78 of the main board 70 in the image processing unit 58 shown in FIG. The poser 82 is displayed on the LCD 40 so as to be superimposed on the video image taken by the television camera 10 output from the decoder 76. Note that the CPU 78 controls the display (display contents) on the LCD 40.

  On the other hand, the LCD 40 is provided with a touch panel, and when a touch operation with which a fingertip or the like touches the screen 40a of the LCD 40 is performed, position information indicating the touched position (coordinates) is given to the CPU 78. As a result, the position of the touch operation performed on the screen 40a of the LCD 40 and the type of operation (tap operation, double tap operation, etc.) are detected by the CPU 78. Then, processing according to the operation is executed by the CPU 78.

  As basic operations on the screen 40a of the LCD 40, there are an operation of inputting an instruction assigned in advance to each of the buttons 300 to 310 and an operation of designating a range of the AF frame 204. The former operation is performed by using the buttons 300 to 310. Is tapped with a fingertip or the like. The latter operation of designating the range of the AF frame 204 is performed, for example, by tapping the position where the AF frame 204 is to be moved on the screen 40a of the LCD 40 on which the captured image is displayed, so that the position becomes the center. The AF frame 204 can be moved. Also, the size and shape of the AF frame 204 can be changed by moving the position of the touched vertex or side to the position where the drag operation is performed by a drag operation of touching and sliding the vertex or side of the AF frame 204 with a fingertip or the like. it can.

  The position, size, and shape of the AF frame 204 can be changed by operating the position operation member 100, the size operation member 102, and the shape operation member 104 of the AF frame operation unit 60 (focus demand 26).

  The menu screen (menu image) displayed on the screen 40a of the LCD 40 will be described. In FIG. 5, a fixed mode selection button 300 displayed as “Fixed”, an object tracking mode selection button 302 displayed as “Object tracking”, A face detection tracking mode selection button 304 displayed as “face detection” and a face recognition tracking mode selection button 306 displayed as “face recognition” are buttons for selecting a control mode of the AF frame. By tapping any one of 306, a desired mode can be selected from the fixed mode, the object tracking mode, the face detection tracking mode, and the face recognition tracking mode.

  The fixed mode (manual mode) is a mode in which an operator designates a desired AF frame range (position, size, shape) by manual operation, and fixes the AF frame at the designated position. As a method for the operator to manually specify a desired AF frame range by a manual operation, in addition to a method of performing a touch operation on the screen 40a of the LCD 40, the position operation member 100 of the AF frame operation unit 60 (focus demand 26 in FIG. 4), It is also possible to operate the size operation member 102 and the shape operation member 104. The range of the AF frame specified in this way is transmitted as AF frame information to the lens CPU of the lens apparatus 12 by the SCI 70a and set as an AF frame in the AF unit 66.

  The object tracking mode is a mode for tracking an arbitrary type of object with the AF frame. In this mode, when the range of the AF frame is specified so that the operator includes an image of an arbitrary object that is desired to be a tracking target for the captured video, the object in that range is set as the tracking target. Then, the image to be tracked is registered as a reference pattern, and the CPU 90 of the pattern matching processing calculation board 72 performs pattern matching processing for detecting an image range that matches the reference pattern on the sequentially obtained captured images. Is called. The CPU 78 of the main board 70 determines the range in which the reference pattern is detected as the AF frame range and transmits it to the lens CPU of the lens device 12. When focus control by AF is not performed in the lens device 12 when AF frame automatic tracking is started (when AF mode is not set), AF is started in conjunction with the start of AF frame automatic tracking. Is also instructed.

  The face detection tracking mode is a mode for tracking the face of an arbitrary person using the AF frame. In this mode, first, a well-known face detection process for detecting a face image of an arbitrary person from a photographed image is performed by the CPU 92 of the face recognition processing calculation board 74. When the operator designates a face image to be tracked from the detected face images, the face image is set as the track target. Thereafter, the CPU 92 of the face recognition processing calculation board 74 performs face detection processing on the sequentially obtained photographed images, and the process of specifying the tracking target face image from the detected face images is the CPU 78 of the main board 70. Is done. The CPU 78 of the main board 70 determines the detected range of the face image to be tracked as the range of the AF frame and transmits it to the lens CPU of the lens device 12.

  The face recognition tracking mode is a mode in which a person's face registered in advance as authentication data is tracked with an AF frame. In this mode, authentication data of the face of the person to be tracked is fetched from the data card 114 loaded in the slot 115 shown in FIG. Then, face detection processing is performed in the CPU 92 of the face recognition processing calculation board 74 in the same manner as in the face detection tracking mode, and the face image to be tracked among the detected face images is known face recognition processing using authentication data. Is detected. The CPU 78 of the main board 70 determines the detected range of the face image to be tracked as the range of the AF frame and transmits it to the lens CPU of the lens device 12.

  In FIG. 5, a set button 308 displayed as “SET” and a reset button 310 displayed as “RESET” are buttons for instructing start and stop of AF frame automatic tracking. 310 is displayed only when a control mode (object tracking mode, face detection mode) in which the operator instructs to start or stop AF frame automatic tracking is selected. The set button 308 and the reset button 310 are buttons that operate in the same manner as the tracking start switch 108 and the tracking stop switch 110 (see FIGS. 2 and 4) of the AF frame operation unit 60.

  In the autofocus system of the present embodiment, the image of the AF frame is displayed on the captured image displayed on the viewfinder 36, and information indicating whether or not the AF frame automatic tracking function is operating normally. , And information indicating the operation mode of the currently selected AF frame automatic tracking function (hereinafter, these pieces of information are collectively referred to as “AF frame automatic tracking information”) can be displayed on the viewfinder 36. Hereinafter, a configuration for realizing this will be described.

  The CPU 78 of the main board 70 in the image processing unit 58 has a function of sending the AF frame automatic tracking information to the lens CPU of the lens device 12. Whether or not the AF frame automatic tracking function is operating normally may be determined based on the processing results of the above-described pattern matching processing and face detection / face recognition processing, for example.

  The AF frame auto-tracking information may be sent from the CPU 78 to the lens CPU at regular intervals, or only when the operation state of the AF frame auto-tracking function (tracking success / tracking failure) or the operation mode changes. Also good. Alternatively, it may be sent only when the transmission of AF frame information tracking information is requested from the lens CPU.

  The lens CPU of the lens device 12 acquires AF frame automatic tracking information from the image processing unit 58 (CPU 78 of the main board 70) and uses the communication between the lens device 12 and the camera body 14 to obtain the image processing unit. The AF frame automatic tracking information acquired from 58 is sent to the camera body 14.

  In general, in a television camera system for broadcasting or business use, the lens device 12 and the camera body 14 are manufactured by different manufacturers, and thus the camera body 14 has a function of displaying AF frame automatic tracking information on the viewfinder 36. There are cases with and without.

  Therefore, the lens CPU of the present embodiment determines that the camera body 14 has a function of displaying the AF frame automatic tracking information on the viewfinder 36 when the camera body 14 requests transmission of AF frame automatic tracking information. Thus, the AF frame automatic tracking information is transmitted to the camera body 14.

  Whether or not the camera body 14 has a function of displaying the AF frame automatic tracking information on the viewfinder 36 is determined by a method other than the determination method based on whether or not there is a transmission request for the AF frame automatic tracking information from the camera body 14. Also good. For example, a mechanical or electronic switch is provided in the lens device 12 or various operation units (the focus operation unit 50, the AF frame operation unit 60, etc.) connected thereto, and the presence or absence of the function is determined according to the state of the switch. You may make it judge. In this case, the AF frame automatic tracking information can be transmitted from the lens CPU to the camera body 14 even if the camera body 14 does not request transmission of the AF frame automatic tracking information.

  When the camera body 14 having the function of displaying the AF frame automatic tracking information on the viewfinder 36 is used, the camera body 14 communicates with the lens device 12 to the lens CPU of the lens device 12 and the AF frame. A request is made to transmit automatic tracking information, and AF frame automatic tracking information is acquired from the lens CPU. The camera body 14 also acquires AF frame information along with AF frame automatic tracking information from the lens CPU.

  The signal processing circuit (corresponding to the viewfinder control means) of the camera body 14 indicates the range (outline) of the AF area in the video signal of the photographed video output to the viewfinder 36 based on the AF frame information acquired from the lens CPU. The image signal of the AF frame is synthesized and displayed.

  Further, the signal processing circuit of the camera body 14 displays the AF frame when the AF frame automatic tracking function is operating normally based on the AF frame automatic tracking information acquired from the lens CPU (when tracking is in progress). ) And the case where the camera is not operating normally (when tracking fails), the display mode of the AF frame displayed on the viewfinder 36 is changed so that the photographer can identify it, and the currently selected AF frame automatic tracking function Displays the operation mode.

  The method of changing the display mode of the AF frame is not particularly limited as long as the cameraman can identify whether or not the AF frame automatic tracking function is normally performed. For example, characters, figures, symbols, etc. It may be used to display AF frame automatic tracking information.

  In the present embodiment, from the viewpoint of enabling the cameraman to easily identify the state of the AF frame automatic tracking function, an aspect in which the display interval, display color, shape, and the like of the AF frame are changed is preferably used. Of course, some or all of these aspects may be combined.

  As a mode of changing the display interval of the AF frame, for example, the AF frame is blinked when tracking is successful, and the AF frame is lit (non-flashing) when tracking fails. As a mode of changing the display color of the AF frame, for example, green is displayed when tracking is successful, and red is displayed when tracking is unsuccessful. Further, as a mode of changing the display shape of the AF frame, as in the example shown in FIG. 6, the AF frame 204A shown in (a) is displayed when tracking is successful, and (b) when tracking fails. The AF frame 204B is displayed.

  The method of displaying the operation mode of the currently selected AF frame automatic tracking function is not particularly limited as long as the cameraman can easily grasp the operation mode. , Graphics, symbols, etc. may be used for display. Further, the display form of the AF frame may be changed according to the currently selected operation mode.

  In the example shown in FIG. 6, “object tracking” is displayed below the AF frames 204A and 204B, indicating that the operation mode of the currently selected AF frame automatic tracking function is the object tracking mode. Has been.

  On the other hand, when the camera body 14 that does not have the function of displaying the AF frame automatic tracking information on the viewfinder 36 is used, the camera body 14 requests the lens CPU to transmit the AF frame automatic tracking information. Therefore, the AF frame automatic tracking information is not erroneously transmitted from the lens CPU to the camera body 14.

  As described above, in the autofocus system according to the present embodiment, when the camera body 14 having the function of displaying the AF frame automatic tracking information on the viewfinder 36 is used, the lens CPU is communicated between the lens device 12 and the camera body 14. The display mode of the AF frame displayed on the viewfinder 36 is changed in accordance with the AF frame automatic tracking information acquired from the above, and the operation mode of the currently selected AF frame automatic tracking function is displayed. . As a result, the cameraman can instantaneously determine whether or not the AF frame automatic tracking function is operating normally in the viewfinder 36 that is constantly viewed, and the operation mode of the currently selected AF frame automatic tracking function. Can be easily grasped.

  In addition, since AF frame automatic tracking information can be transmitted and received using existing lines (between the image processing unit 58 and the lens device 12 and between the lens device 12 and the camera body 14), cost increase can be suppressed. It can be realized easily.

  In addition, when the camera body 14 that does not have the function of displaying the AF frame automatic tracking information on the viewfinder 36 is used, the AF frame automatic tracking information is not sent from the lens device 12 to the camera body 14. 14 malfunctions can be prevented.

  The autofocus system of the present invention has been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the scope of the present invention. Of course.

DESCRIPTION OF SYMBOLS 1 ... Autofocus system, 10 ... Television camera, 12 ... Lens apparatus, 14 ... Camera body, 26 ... Focus demand, 36 ... Viewfinder, 40 ... Liquid crystal display (LCD) with a touch panel, 50 ... Focus operation part, 58 ... Image Processing unit 60 ... AF frame operation section 66 ... AF unit 68 ... Down converter 70 ... Main board 72 ... Pattern matching processing calculation board 74 ... Face recognition processing calculation board 76 ... Decoder 78, 90, 92 ... CPU, 82 ... Superimposer, 114 ... Data card, 115 ... Slot, 200 ... AF area, 204 ... AF frame, 300 ... Fixed mode selection button, 302 ... Object tracking mode selection button, 304 ... Face detection tracking mode selection Button 306 ... face recognition tracking mode selection button, 08 ... set button, 310 ... reset button

Claims (5)

Imaging means for imaging a subject image formed by an optical system;
Auto focus means for adjusting the focus of the optical system so that a subject within a predetermined AF frame is in focus among the captured images captured by the imaging means;
AF frame automatic tracking means for automatically tracking the AF frame to the tracking target subject so as to focus on a predetermined tracking target subject;
Viewfinder control means for controlling display of a viewfinder for displaying a photographed image taken by the imaging means;
AF frame information output means for outputting AF frame information for displaying the AF frame on the viewfinder to the viewfinder control means;
Information indicating whether or not the AF frame auto-tracking by the AF frame auto-tracking unit is normally performed, and AF frame auto-tracking information including the operation mode of the AF frame auto-tracking unit are sent to the viewfinder control unit. Automatic tracking information output means for outputting;
An autofocus system characterized by comprising   2. The auto finder according to claim 1, wherein the viewfinder control unit changes the display mode of the AF frame and displays an operation mode of the AF frame automatic tracking unit based on the AF frame automatic tracking information. Focus system.   3. The autofocus system according to claim 2, wherein the viewfinder control means displays the operation mode of the AF frame automatic tracking means using characters, figures, or symbols.   The viewfinder control means may identify the AF in the viewfinder so that it can be discriminated whether the AF frame automatic tracking by the AF frame automatic tracking means is normally performed or not. The autofocus system according to claim 2 or 3, wherein the frame is displayed in a different manner.   When the viewfinder control means does not have a function of changing the display mode of the AF frame in accordance with the AF frame automatic tracking information, the automatic tracking information output unit includes the AF frame automatic tracking in the viewfinder. 5. The autofocus system according to claim 1, wherein information is not output.

Images