JP2010152135A - Safe area warning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe area warning device that properly warns a camera operator so that a subject does not move outside a safe area by tracking the subject to be imaged, using an AF frame automatic tracking function in a TV camera with the AF frame automatic tracking function. <P>SOLUTION: In a TV camera system 1, an AF unit 40 is mounted on the lens device 12 of the TV camera 10. The system 1 has an AF frame automatic tracking device 18 for causing an AF frame showing a range of the subject to be automatically focused by the AF unit 40 to follow a predetermined subject. In the AF frame automatic tracking device 18, a safe area limiting the range of the field angle for imaging a subject to a predetermined range is specified and set by a safe area specifying section 60. In this case, when the subject to be tracked by the AF frame is likely to move outside the safe area, a lamp is turned on by a safe area warning display section 62, thereby giving a warning. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a safe area warning device, and more particularly to a television camera system having an AF frame automatic tracking function for automatically tracking a desired subject in an AF area (AF frame) that is a target range for focusing in autofocus (AF). The present invention relates to an applied safe area warning device.

  Currently, most of the broadcast TV cameras are high-definition TV cameras (HD cameras), and HD cameras shoot HD (high definition) image quality (HD images) and have a screen size (resolution) of 16: 9 aspect ratio. HD video signal corresponding to video of 1920 × 1080) is output.

  On the other hand, there are many general users who still use televisions that support SD (standard) image quality (SD video) with a screen size (resolution: 640 × 480) having an aspect ratio of 4: 3.

  When viewing a video shot with an aspect ratio of 16: 9 shot using an HD camera on a TV with an aspect ratio of 4: 3 (screen size), the video at the left and right ends of the shot video is displayed on the screen. Is not displayed.

  For this reason, when shooting using an HD camera, the cameraman can shoot in a field of view range corresponding to an aspect ratio of 4: 3 so that the subject to be shot is displayed on a TV with an aspect ratio of 4: 3. In some cases, it is necessary to perform an angle-of-view operation (pan / tilt operation, etc.) so that the subject can be accommodated.

  On the other hand, a shot image with an aspect ratio of 16: 9 is displayed on the viewfinder of the HD camera, but the angle of view range (shooting range) with an aspect ratio of 4: 3, that is, an aspect ratio of 16: 9 is superimposed on the screen. An aspect marker that indicates the angle of view when the maximum range with an aspect ratio of 4: 3 is cut out from the center of the angle of view range of 9 and is actually displayed on the screen than the angle of view range with an aspect ratio of 4: 3. Display a safe area marker indicating the range of angle of view in which the subject is reliably displayed on a TV with an aspect ratio of 4: 3, which can narrow the field of view of the captured video. By operating the camera so that it is within the angular range, the cameraman is alerted so that only the person viewing the HD video screen can see the subject for shooting. What was Unishi is known.

  Note that the safe area marker is an aspect marker that indicates a field angle range corresponding to the screen size with a predetermined aspect ratio, and may be cut when a captured image in the field angle range is displayed on the TV. This is a range excluding the area of the part, and is set as a field angle range that is reliably displayed on an arbitrary television. For example, the safe area marker is set to a predetermined ratio (for example, 95%) with respect to the field angle range of the aspect marker, and the ratio can be changed by the user within the predetermined range. . In this specification, the field angle range of the safe area marker is referred to as a safe area, and the field angle range of the aspect marker, that is, the field angle range corresponding to a predetermined aspect ratio is not set in the safe area marker. It shall correspond to what is called.

  Conventionally, in an autofocus (AF) system that automatically adjusts the focus of a camera, the camera must be instructed where to focus. At this time, in a general camera or the like, the position to be focused is fixed at the center of the shooting range, and for example, the person in the center of the shooting range is focused.

  However, when shooting a moving subject, it is inconvenient if the focus position is fixed in this way. Therefore, for example, when shooting a scene where the subject is moving rapidly, such as sports, using a TV camera or the like, there is an AF frame automatic tracking system that automatically tracks an AF area (AF frame) to the subject for the purpose of focusing on the subject. It is known (see, for example, Patent Document 1). In this specification, an 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.

Also, an image representing a person's face is detected from the captured image, and the face that is the subject is automatically focused, or the area representing the detected face is enlarged. A digital camera that automatically changes the zoom magnification is known (for example, see Patent Document 2).
JP 2006-267221 A JP 2004-320286 A

  By the way, when shooting with the subject to be shot as the tracking target of the AF frame, the cameraman checks the view angle operation with the safe area marker of the viewfinder so that the subject to be shot does not go outside the safe area. Even if this is done, attention may be paid to other operations and the like, and the subject to be photographed may move out of the safe area carelessly.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a safe area warning device that can appropriately alert a photographer so that a subject to be photographed does not move outside the safe area. To do.

  In order to achieve the object, a safe area warning device 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 among captured images captured by the imaging unit. Auto-focus means for adjusting the focus of the optical system so that the subject within the frame is in focus, and AF for automatically tracking the AF frame so that the subject to be tracked is in focus so as to focus on the subject to be tracked A safe area warning device used in a television camera system provided with a frame auto-tracking means, and an angle-of-view range for photographing a subject to be photographed with respect to an angle-of-view range of an entire captured image captured by the imaging means Safe area setting means for setting the predetermined angle of view range as a safe area when limiting the predetermined angle of view range to the predetermined angle of view range, and the AF frame outside the safe area Determining means for determining whether or not there is a risk of moving to the safe area; and warning means for giving a warning to the effect when the AF means determines that the AF frame may move outside the safe area It is characterized by having.

  A safe area warning device according to a second aspect of the present invention is the safe area warning device according to the first aspect of the invention, wherein the determining means determines that the AF frame when the frame line of the AF frame approaches the frame line of the safe area within a predetermined distance. Is determined to be likely to move outside the safe area.

  The safe area warning device according to a third aspect is the invention according to the first or second aspect, wherein the warning means gives the warning by lighting a lamp, vibration by a vibration means, or displaying information on a view funder. It is characterized by doing.

  According to a fourth aspect of the present invention, there is provided a safe area warning device that focuses on a subject within a predetermined AF frame out of a captured image captured by an imaging unit that captures a subject image formed by an optical system. An autofocus unit that adjusts the focus of the optical system so as to match, and a face of a person is detected from the photographed image as a subject to be tracked by face detection processing, and the AF is adjusted so that the detected face is in focus A safe area warning device used in a television camera system provided with an AF frame automatic tracking unit that automatically tracks a frame to the detected face, with respect to a field angle range of an entire captured image captured by the imaging unit Safe area setting means for setting the predetermined angle of view range as a safe area when the angle of view of the subject to be imaged is limited to the predetermined angle of view range; Face detection means for detecting a human face from the captured images picked up by the image pickup means by face detection processing in the AF frame automatic tracking means, and a face detected by the face detection means outside the safe area. A determination means for determining whether or not there is a risk of movement; a warning means for giving a warning to that effect when the determination means determines that the face may move outside the safe area; It is characterized by having.

  According to the present invention, it is possible to appropriately alert the photographer so that the subject to be photographed does not move outside the safe area.

  The best mode for carrying out a safe area warning device according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing the overall configuration of a television camera system to which the present invention is applied. The television camera system 1 shown in the figure includes, for example, a television camera 10 for broadcasting or business use, an AF frame automatic tracking device 18 and the like.

  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, a viewfinder 16 is installed in the camera main body 14, and a captured image of the television camera 10 is displayed on the viewfinder 16. The viewfinder 16 displays various types of information other than the captured video. For example, an image (frame image) showing the currently set AF frame range (position, size, shape). ) Is superimposed on the captured video and displayed. The AF frame indicates a range (outline) of a subject to be focused by autofocus (AF).

  The lens device 12 includes a photographic lens (zoom lens) attached to the lens mount of the camera body 14, and the subject forms an image on the imaging surface of the imaging element of the camera body 14 by the photographic lens. ing. Although not shown, the photographic lens 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. The 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 40, a lens CPU 42, and the like. The lens CPU 42 performs overall control of the entire lens device 12. The AF unit 40 is a processing unit for acquiring information necessary for performing focus control (automatic focus adjustment) by AF, and is configured from an AF processing unit, an AF imaging circuit, and the like (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 element, subject light branched from subject light incident on the imaging element of the camera body 14 is imaged by a half mirror or the like disposed on the optical path of the photographing lens. 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 42 acquires AF frame information (AF frame information) indicating the range (contour) of the AF area from the AF frame automatic tracking device 18 as will be described later, and within the AF frame designated by the AF frame information. The range is designated as an AF area to the AF processing unit. 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. 2, the AF area 200 is set as a rectangular area with respect to the imaging area 202 (or imaging range) of the imaging element in the camera body 14. A frame 204 indicating the outline of the AF area 200 indicates an AF frame, and a subject photographed in an angle of view range of the AF area 200 (in the AF frame 204) is a target to be focused by AF.

  In the present 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. It is assumed that the range of the AF frame is changed when at least one of the three elements of position, size, and shape is changed.

  The lens device 12 is connected to the camera body 14 via a cable or directly, and various information can be exchanged between the lens device 12 and the camera body 14. As a result, information on the AF frame currently set in the AF unit 40 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 16 by processing in the camera body 14. The image of the AF frame corresponding to the size and shape is superimposed and displayed.

  The AF frame automatic tracking device 18 is a device that mainly performs AF frame automatic tracking function processing (AF frame automatic tracking processing), and performs safe area warning function processing (safe area warning processing) using this function. Device. The AF frame automatic tracking device 18 is arranged as an external device with respect to the lens device 12 and the camera body 14. Then, it is connected to the lens device 12 by a cable or the like, and various signals can be exchanged with the lens CPU 42 by serial communication or the like. Thereby, AF frame information for specifying the range of the AF frame is given from the AF frame automatic tracking device 18 to the lens CPU 42 of the lens device 12, and the AF frame range in the AF unit 40 is set based on the AF frame information. . The AF frame automatic tracking device 18 may be installed in the lens device 12 or the camera body 14 or may be built in.

  The AF frame automatic tracking device 18 is provided with a video input connector for capturing a video signal, and the video output connector of the camera body 14 is connected to the video input connector with a cable. As a result, the video signal of the captured video output from the video output connector of the camera body 14 is input to the AF frame automatic tracking device 18.

  Note that the video signal output from the video output connector of the camera body 14 is an HDTV signal of HD quality video, but considering the required image quality and processing burden in the AF frame automatic tracking device 18, SD quality video is sufficient. It is. Therefore, the HDTV signal output from the camera body 14 is converted (down-converted) into a standard television [NTSC (National Television System Committee)] video signal (SDTV signal) by a down converter, and the AF frame automatic tracking device 18 You may make it input into a video input connector.

  When executing the AF frame automatic tracking process, the AF frame automatic tracking device 18 sequentially captures one frame of the captured image from the video signal input from the camera body 14 and selects a predetermined subject to be tracked from the captured image. The process which detects 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 42 of the lens apparatus 12 as AF frame information.

  As shown in the figure, the AF frame automatic tracking device 18 includes a CPU 50, an AF frame operation unit 52, a tracking start switch 54, a tracking stop switch 56, a decoder 58, a safe area designation unit 60, a safe area warning display unit 62, and the like. ing.

  The CPU 50 is an arithmetic processing unit that performs overall processing in the AF frame automatic tracking device 18, and details of the processing will be described as appropriate.

  The AF frame operation unit 52 includes an operation member for a user to manually operate the range of the AF frame, and a detector that electrically detects the setting state of the operation member. For example, the AF frame operation unit 52 performs AF for an imaging area (shooting range). Position operation member (for example, joystick, trackball, etc.) for changing the position of the frame by manual operation, size operation member (for example, knob) for changing the size of the AF frame by manual operation, shape of the AF frame ( A shape operation member (for example, a knob) or the like for changing the (aspect ratio) manually is provided. The setting states of these operation members are detected by the detector and given to the CPU 50. When the AF frame automatic tracking process is not executed, the CPU 50 determines the range (position, size, shape) of the AF frame based on the setting state of each operation member, and indicates the AF frame range. The frame information is transmitted to the lens CPU 42 of the lens device 12.

  The tracking start switch 54 is a switch for the user to instruct the start of AF frame automatic tracking, and the tracking stop switch 56 is a switch for the user to instruct to stop the AF frame automatic tracking. The CPU 50 starts or stops the AF frame automatic tracking process according to the state of the switches 54 and 56.

  The decoder 58 is a circuit for converting the video signal of the video captured by the television camera 10 input from the camera body 14 to the AF frame automatic tracking device 18 into data that can be digitally processed by the CPU 50 or the like.

  The safe area designating unit 60 allows the user to set a predetermined angle of view range (the range of shooting of the TV camera 10) with respect to the angle of view of the entire shot image of the TV camera 10 shot by the image pickup area of the image pickup device of the camera body 14. This is an operation unit for designating the (shooting range) as a safe area. The safe area indicates an angle of view range (shooting range) in which the shot video is reliably displayed on the screen of the assumed display device when the shot video of the TV camera 10 is displayed on a display device such as a television. By performing the angle of view operation (pan / tilt operation, zoom operation, etc.) so that the photographer shoots the subject to be photographed within the field angle range of the safe area, it is ensured with the display device that the subject to be photographed is assumed. It is guaranteed to be displayed. Details will be described later.

  The safe area warning display unit 62 is a display for turning on a lamp such as an LED as a warning when a subject to be photographed is about to move outside from an angle of view range designated as a safe area by the safe area designating unit 60. For example, it is installed beside the screen of the viewfinder 16 or the like.

  Processing contents in the AF frame automatic tracking device 18 having the above-described components will be described. First, an example of the AF frame automatic tracking process among the AF frame automatic tracking process and the safe area warning process will be described. When the AF frame automatic tracking is not performed, the user operates the AF frame operation unit 52 while looking at the screen of the viewfinder 16, operates the angle of view, and performs AF so as to surround the shooting target subject to be tracked. Set the frame range. Then, the tracking start switch 54 is turned on.

  The CPU 50 appropriately captures a frame-unit (one-frame unit) captured image by the video signal input from the TV camera 10 via the decoder 58, and applies the captured image when the tracking start switch 54 is turned on. A known face detection process is executed to determine whether or not a person's face (face image) is included in the AF frame range. If a face is included, the face is set as a tracking target, and the range of the detected face (face image) is changed as the AF frame range. Then, AF frame automatic tracking processing by face detection processing is started.

  When the AF frame automatic tracking process by the face detection process is started, the CPU 50 sequentially captures the captured images of the television camera 10 and detects a human face image from the captured captured images by the face detection process. Then, the face image range closest to the current AF frame range is changed as a new AF frame range. Thereby, the tracking target face is tracked by the AF frame.

  On the other hand, if the face of the AF frame when the tracking start switch 54 is turned on does not include a human face, the image within the range of the AF frame is stored as a reference pattern. Then, AF frame automatic tracking processing by pattern matching processing is started.

  When the AF frame automatic tracking process by the pattern matching process is started, the CPU 50 sequentially captures the captured images of the television camera 10 and detects an image range that matches the reference pattern from the captured captured images by a known pattern matching process. Then, the detected image range is changed as a new AF frame range. Thereby, the tracking target object other than the face is tracked by the AF frame.

  When the AF frame automatic tracking process by the face detection process or the pattern matching process is being performed, if the user turns on the tracking stop switch 56, the AF frame automatic tracking process of the CPU 50 is stopped and the AF frame automatic tracking is not performed.

  Note that the content of the AF frame automatic tracking process described above is an example, and a face or an arbitrary object other than the face may be tracked by the AF frame according to other processing content.

  Next, the safe area warning process in the AF frame automatic tracking device 18 will be described. The video captured by the TV camera 10 is an HD (high definition) image quality (HD video). In this case, as shown in FIG. 3, the screen (view angle range) 300 of the entire captured video has an aspect ratio of 16: 9. It will be of the screen size.

  On the other hand, when an image captured by the TV camera 10 having an aspect ratio of 16: 9 is displayed on a display device having a screen size of 4: 3, the field angle range (photographing range) displayed on the screen of the display device is The captured image has a field angle range indicated by a broken line frame 302 in FIG.

  If the subject is photographed in consideration that the subject to be photographed is surely displayed on a display device having a screen size of 4: 3 aspect ratio, the photographer views the subject to be photographed in the image of the broken line frame 302 in FIG. It is necessary to perform an angle-of-view operation (pan / tilt operation, etc.) so as not to go out of the angle range.

  In addition to such a case, the field angle range of the photographed image displayed on the display device with respect to the field angle range of the entire photographed image photographed by the television camera 10 (the field angle range of the television camera 10) is not limited. When limited to a small range, it is necessary to perform an angle-of-view operation so that a subject to be imaged is captured within the limited range of angle of view.

  Thus, when it is desired to limit the field angle range for capturing the subject to be captured in this way to a predetermined field angle range, the user uses the safe area designating unit 60 in FIG. By designating, the CPU 50 sets the safe area according to the designation.

  For example, in the safe area designating unit 60, a characteristic field angle range can be designated by the safe area designating unit 60, and one of them is a display device having a screen size with an aspect ratio of 4: 3. As shown in FIG. 3, an angle of view range of 4: 3 aspect ratio (broken line frame 302; hereinafter, angle of view range 302) can be designated as a safe area as shown in FIG. In addition, even in a display device having a screen size with an aspect ratio of 4: 3, there may be a case where a peripheral portion of a captured image in the field of view range 302 is not displayed on the screen. %) Field angle range 304 can also be designated and set as a safe area. The ratio may be selected from predetermined values (percent values such as 95, 90, 85, 80, etc.), or an arbitrary value may be designated.

  Similarly to the display on the display device having the screen size of 4: 3, the television camera 10 is considered in consideration of the display on the display device having the same screen ratio of 16: 9 as the captured image of the television camera 10. The angle of view range 300 may be designated as a safe area, or a predetermined angle of view angle range may be designated as the safe area.

  When the CPU 50 sets the safe area designated by the safe area designating unit 60 as described above, the subject to be tracked is regarded as the subject to be photographed when the AF frame automatic tracking process is being executed, and the subject to be tracked When there is a possibility that the AF frame that tracks is moved to the outside of the safe area, the safe area warning display unit 62 notifies the cameraman of that fact.

  For example, it is assumed that an angle of view range 302 having an aspect ratio of 4: 3 is set as the safe area 310 with respect to the angle of view range 300 of the television camera 10. At this time, as shown in FIG. 4, when the frame line of the AF frame 204 is in contact with the frame line of the safe area 310, the lamp of the safe area warning display unit 62 is turned on.

  Specifically, the upper left vertex of the view angle range 300 is the origin, the horizontal direction is the x axis, the vertical direction is the y axis, and the coordinates of the four corner vertices of the view angle range 300 are the upper left vertex (0, 0) and upper right, respectively. It is assumed that the vertex (X, 0), the lower left vertex (0, Y), and the lower right vertex (X, Y). In addition, the coordinates of the four corner vertices of the safe area 310 are respectively an upper left vertex (xL, yT), an upper right vertex (xR, yT), a lower left vertex (xL, yB), and a lower right vertex (xR, yB). However, in the example of FIG. 3, yT = 0 and yB = Y.

If the coordinates of the center of the AF frame 204 are (x0, y0), the horizontal width of the AF frame 204 is m, and the vertical width is n, the following four conditional expressions (1) to (4),
xL <x0-m / 2 (1)
xR> x0 + m / 2 (2)
yT <y0-n / 2 (3)
yB> y0 + n / 2 (4)
When the condition is satisfied, the AF frame is within the safe area 310, and the frame line of the AF frame 204 is not in contact with the frame line of the safe area 310. At this time, the CPU 50 turns off the lamp of the safe area warning display unit 62.

  On the other hand, when any one of the conditional expressions (1) to (4) is not satisfied, the frame line of the AF frame 204 is in contact with the frame line of the safe area 310 (or further outward). Moving state). At this time, the CPU 50 turns on the lamp of the safe area warning display unit 62 to notify that there is a possibility that the subject to be photographed may move outside the safe area.

A warning is issued before the border of the AF frame 204 is in contact with the border of the safe area 310, that is, when the border of the AF frame 204 approaches the border of the safe area 310 within a predetermined distance. For example, the conditional expressions (1) to (4)
xL + α <x0−m / 2 (1)
xR-α> x0 + m / 2 (2)
yT + β <y0−n / 2 (3)
yB-β> y0 + n / 2 (4)
(However, α and β are positive values)
Instead, the lamp of the safe area warning display unit 62 may be turned on when any one of the conditional expressions (1) to (4) is not satisfied.

  Further, the present invention is not limited to the case where it is determined that the AF frame 204 (photographing subject) may move outside the safe area based on the conditional expressions (1) to (4) as described above. For example, it may be determined that the AF frame 204 may move outside the safe area in consideration of the moving direction of the AF frame 204 and the like.

  As described above, in the above embodiment, the subject within the range of the AF frame when the AF frame automatic tracking process is being performed (the subject to be tracked) is regarded as the subject for shooting, but the AF frame automatic tracking process is performed. Even if not, face detection may be performed, and all detected faces or the face selected by the user from among them may be taken as a subject for photographing, and the face range may move outside the safe area. If it is determined that there is, the lamp of the safe area warning display unit 62 may be turned on.

  In addition to or in combination with the safe area warning display unit 62, a cameraman extending a vibration generating device that generates vibration to a mount (such as a pedestaldry) on which the TV camera 10 is mounted is provided. When it is installed on a gripping operation stick or the body of a photographer and it is determined that the subject to be photographed may move outside the safe area, a vibration is generated by the vibration generator, and this is indicated to the photographer. May be notified.

  Further, instead of or in combination with the safe area warning display unit 62, a warning is displayed on the screen of the viewfinder 16 that there is a possibility that the subject to be photographed may move outside the safe area. Also good. The warning display in this case may be made to turn on a lamp in the screen (switch to a color different from that at the time of non-warning at the time of warning), as with the safe area warning display section 62, or use characters, symbols, figures, etc. The warning may be given by displaying any information.

  In addition to a safe area marker (warning line) for displaying a warning, a warning line is provided slightly inside, and when there is a possibility that the subject to be photographed may move outside the warning line You may make it call attention by a method (display etc.). For example, in addition to the left and right warning lines, a warning line may be provided slightly before that so that a warning warning is issued.

  In the above embodiment, the safe area is specified and set by the safe area specifying unit 60 of the AF frame automatic tracking device 18. For example, the safe area is set in the camera body 14 and the safe area is set in the viewfinder 16. If there is a function for displaying a safe area marker or the like indicating the field angle range, the AF frame automatic tracking device 18 may acquire the information from the camera body 14 and set the safe area.

[BRIEF DESCRIPTION OF THE DRAWINGS] It is the block diagram which showed the whole structure of the television camera system with which this invention is applied. It is explanatory drawing used for description of AF frame. It is explanatory drawing used for description of a safe area. It is explanatory drawing used for description of a safe area warning display process. It is explanatory drawing used for description of this process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Television camera system, 10 ... Television camera, 12 ... Lens apparatus, 14 ... Camera apparatus, 16 ... Viewfinder, 18 ... AF frame automatic tracking apparatus, 42 ... Lens CPU, 50 ... CPU, 52 ... AF frame operation part, 54 ... Tracking start switch, 56 ... Tracking stop switch, 58 ... Decoder, 60 ... Safe area designation part, 62 ... Safe area warning display part

Claims (4)

An imaging unit that captures a subject image formed by the optical system, and a focus adjustment of the optical system is performed so that a subject within a predetermined AF frame is in focus among the captured images captured by the imaging unit. A safe area warning device used in a television camera system including an autofocus unit and an AF frame automatic tracking unit that automatically tracks the AF frame to the subject to be tracked so that a predetermined subject to be tracked is in focus. There,
The predetermined field angle range when the field angle range for capturing a subject to be captured is limited to a predetermined field angle range as a safe area with respect to the field angle range of the entire captured image captured by the imaging unit. Safe area setting means,
Determination means for determining whether or not the AF frame may move outside the safe area;
Warning means for giving a warning to that effect when the determination means determines that the AF frame may move outside the safe area;
A safe area warning device characterized by comprising:   The determination means determines that the AF frame may move outside the safe area when the frame line of the AF frame approaches the frame line of the safe area within a predetermined distance. The safe area warning device according to claim 1.   3. The safe area warning device according to claim 1, wherein the warning means performs the warning by lighting a lamp, vibration by a vibration means, or displaying information on a view funder. An imaging unit that captures a subject image formed by the optical system, and a focus adjustment of the optical system is performed so that a subject within a predetermined AF frame is in focus among the captured images captured by the imaging unit. An autofocus unit and an AF that automatically detects the face of a person from the photographed image as a tracking target subject by face detection processing and automatically tracks the detected AF frame so that the detected face is in focus A safe area warning device used in a television camera system equipped with automatic frame tracking means,
The predetermined field angle range when the field angle range for capturing a subject to be captured is limited to a predetermined field angle range as a safe area with respect to the field angle range of the entire captured image captured by the imaging unit. Safe area setting means,
A face detection unit for detecting a human face from a photographed image captured by the imaging unit by a face detection process in the AF frame automatic tracking unit;
Determining means for determining whether or not the face detected by the face detecting means may move outside the safe area;
Warning means for giving a warning to that effect when it is determined by the determining means that the face may move outside the safe area;
A safe area warning device characterized by comprising:

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