JP2009177460A - Viewfinder display circuit and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a viewfinder (VF) display circuit and method capable of easily performing focusing by providing a video signal that facilitates focusing during focusing in a television camera. <P>SOLUTION: A camera signal processing section 105 creates a video signal and a contour correcting signal from an inputted optical signal. A focus area setting section 106 sets a focus area within a screen of a color VF 112. In focal point adjustment of an optical lens, VF processing sections 107, 108, 109 decrease a signal level of the video signal inside the focus area, keep as it is the signal level of the video signal outside the focus area, and create a mixing signal of the video signal and the contour correcting signal. A luminance signal creating section 110 creates a luminance signal from the mixing signal. In focal point adjustment of the optical lens, a lens control section 104 changes over a switcher 111 so as to provide the luminance signal to the color VF 112. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a viewfinder display circuit and method for displaying a video signal on a viewfinder of a television camera when focus adjustment is performed by manually rotating an optical lens of a television camera used in a studio of a broadcasting station or the like.

  In the studio of a broadcasting station, a clear broadcast video is sent out by operating an optical lens of a broadcasting television camera by a cameraman. The broadcast television camera has three types of solid-state imaging devices (CCD: Charge Coupled Device) for R channel, G channel, and B channel, and is based on imaging signals obtained by these three types of solid-state imaging devices. The contour correction signal is generated, and the generated contour correction signal (DTL: Detail) is added to the imaging signal and transmitted.

  Conventionally, a viewfinder display circuit has been proposed for a cameraman operating a broadcast television camera to display a video signal on a viewfinder and perform focus adjustment and other adjustment operations while viewing the video signal displayed on the viewfinder. (For example, Patent Document 1). The video signal displayed on the viewfinder is generally a video signal whose contour has been corrected, that is, an imaging signal to which the created contour correction signal has been added.

  FIG. 8 is a block diagram of a conventional viewfinder display circuit. This viewfinder display circuit includes a CCD unit 801, a camera signal processing unit 802, a peaking processing unit 803, an amplifier 804, a mixer 805, a viewfinder (VF: View Finder) 806, and a lens control unit 807. With

  The CCD unit 801 has three types of solid-state image sensors for R channel, G channel, and B channel. The camera processing unit 802 creates a video signal from the output of the CCD unit 801 and outputs the created video signal as a camera output signal. The camera processing unit 802 also creates a contour correction signal DTL based on the output from the CCD unit 801.

  The peaking processing unit 803 performs peaking processing on the input video signal. The amplifier 804 amplifies the input contour correction signal DTL to a predetermined level. The mixer 805 mixes the video signal subjected to the peaking process and the amplified contour correction signal DTL. The VF 806 displays the mixed video signal. That is, the contour-corrected video signal is displayed on the VF 806.

The cameraman adjusts the level according to the volume of the peaking processing unit 803 and the volume of the amplification unit 804, and makes it easy to focus by looking at an image with an emphasized outline displayed on the VF 806. Adjust the focus. Note that the focus adjustment portion of the VF 806 is generally the center of the screen, which is an easily viewable portion of the screen.
JP 2002-185821 A

  As already described, the cameraman displays an easy-to-focus image on the VF 806 while adjusting the level of the peaking processing unit 803 and the level of the amplification unit 804. Since the level of the peaking processing unit 803 is processed only with the horizontal component in an analog manner, steep filter processing cannot be performed. If the level of the peaking processing unit 803 is increased too much, not only DTL but also emphasis is given. Even signals that do not have to be emphasized (for example, noise) may be emphasized, which makes the video difficult to view.

  The peaking processing unit 803 makes it easy to see the contour signal so that a contrast difference between the video signal and the contour signal is generated, and only the contour correction signal DTL is emphasized only by adjusting the level of the amplification unit 804 of the contour correction signal DTL. Can not. That is, considerable skill is required to adjust the level of the contour correction signal DTL while balancing the level adjustment of the peaking processing unit 803 and to emphasize only the contour correction signal DTL.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a viewfinder display circuit and method capable of providing a video signal that can be easily focused and focusing easily in focusing of a television camera.

A viewfinder display circuit according to claim 1 comprises:
A viewfinder that displays video signals to adjust the focus of the optical lens of the TV camera;
A video signal and a contour correction signal creating means for creating a video signal and a contour correction signal from the optical signal input through the optical lens;
A focus area setting means for setting a focus area in the viewfinder screen;
At the time of focus adjustment of the optical lens, the signal level in the focus area of the video signal created by the video signal and the contour correction signal creating unit is reduced and the video created by the video signal and the contour correction signal creating unit Mixed signal creating means for creating a mixed signal of the video signal and the contour correction signal created by the video signal and the contour correction signal creating means while leaving the signal level outside the focus area of the signal;
A luminance signal creating means for creating a luminance signal from the mixed signal;
Control means for controlling the luminance signal to be supplied to the viewfinder at the time of focus adjustment of the optical lens.

A viewfinder display circuit according to claim 2 comprises:
The mixed signal generating means is
An attenuator for attenuating the video signal created by the video signal and the contour correction signal creating means;
A first input unit to which the video signal created by the video signal and the contour correction signal creation unit is input and a second input unit to which the video signal attenuated by the attenuator is input, and the focal point of the optical lens When the adjustment is performed and the subject is within the focus area, the video signal attenuated by the attenuator is output. When the focus of the optical lens is not adjusted or the subject is outside the focus area, the video signal and the contour are output. A first switch for switching so as to output the video signal created by the correction signal creating means;
A mixer for mixing the output of the first switch and the contour correction signal;
A first input unit to which an output of the first switch is input and a second input unit to which an output of the mixer is input; and when the focus of the optical lens is adjusted, the output of the mixer is output; And a second switching unit that performs switching so as to output the output of the first switching unit when not adjusting the focus of the optical lens.

A viewfinder display circuit according to claim 3 comprises:
The video signal is a digital video signal, and the attenuator is a shift register.

A viewfinder display circuit according to claim 4 comprises:
The focus adjustment of the optical lens may be performed when the focus ring of the optical lens is rotated or when focus adjustment is selected by an operation item of the television camera.

A viewfinder display circuit according to claim 5 comprises:
The focus area may be variable up to the entire screen with reference to the center of the viewfinder screen.

A viewfinder display circuit according to claim 6 comprises:
A viewfinder that displays a video signal to adjust the focus of the optical lens of the TV camera;
A video signal and contour correction signal creating means for creating a video signal and a contour correction signal from an optical signal input through the optical lens;
A focus area setting means for setting a focus area on the viewfinder screen;
A luminance signal creating means for creating a luminance signal from the video signal;
When the focus of the optical lens is adjusted, the signal level of the luminance signal in the focus area is reduced, and the signal level of the luminance signal outside the focus area is left as it is, and the luminance signal and the contour correction signal are A mixed signal creating means for creating a mixed signal;
Control means for controlling the mixed signal to be supplied to the viewfinder when adjusting the focus of the optical lens.

A viewfinder display circuit according to claim 7 comprises:
The mixed signal generating means is
An attenuator for attenuating the luminance signal created by the luminance signal creating means;
A first input unit to which the luminance signal generated by the luminance signal generation unit is input; and a second input unit to which the luminance signal attenuated by the attenuator is input. The luminance signal attenuated by the attenuator is output when the subject is in the focus area, and is generated by the luminance signal generating means when the focus of the optical lens is not adjusted or when the subject is outside the focus area. A first switch for switching to output a luminance signal;
A mixer for mixing the output of the first switch and the contour correction signal;
A first input unit to which an output of the first switch is input, and a second input unit to which an output of the mixer is input, and outputs the output of the mixer during focus adjustment of the optical lens, And a second switch for switching so as to output the output of the first switch when the focus of the optical lens is not being adjusted.

A viewfinder display circuit according to claim 8 comprises:
The video signal is a digital video signal, and the attenuator is a shift register.

A viewfinder display circuit according to claim 9 comprises:
The focus adjustment of the optical lens may be performed when the focus ring of the optical lens is rotated or when focus adjustment is selected by an operation item of the television camera.

A viewfinder display circuit according to claim 10 comprises:
The focus area may be variable up to the entire screen with reference to the center of the viewfinder screen.

A viewfinder display method according to claim 11 comprises:
A video signal and contour correction signal creating step for creating a video signal and contour correction signal from an optical signal input through an optical lens of a television camera;
A focus area setting step for setting a focus area in a viewfinder screen on which a video signal is projected to adjust the focus of the optical lens;
When adjusting the focus of the optical lens, the signal level in the focus area of the video signal created in the video signal and contour correction signal creation step is reduced, and the video created in the video signal and contour correction signal creation step A mixed signal creating step for creating a mixed signal of the video signal and the contour correction signal created in the video signal and the contour correction signal creating step while leaving the signal level outside the focus area of the signal;
A luminance signal creating step of creating a luminance signal from the mixed signal;
A control step for controlling the luminance signal to be supplied to the viewfinder when the focus of the optical lens is adjusted.

A viewfinder display method according to claim 12 includes:
A video signal and contour correction signal generation step for generating a video signal and a contour correction signal from an optical signal input through an optical lens of a television camera;
A focus area setting step for setting a focus area in a viewfinder screen on which a video signal is projected to adjust the focus of the optical lens;
A luminance signal creating step of creating a luminance signal from the video signal;
At the time of focus adjustment of the optical lens, the signal level of the luminance signal in the focus area is reduced, and the signal level of the luminance signal outside the focus area is left as it is, and the video signal and the contour correction signal are A mixed signal creation step for creating a mixed signal;
A control step for controlling the luminance signal to be supplied to the viewfinder when the focus of the optical lens is adjusted.

  According to the viewfinder display circuit of the first aspect, when the focus of the optical lens is adjusted, that is, when the optical lens of the TV camera is manually rotated and the focus adjustment is performed while viewing the output video signal of the TV camera's viewfinder, The signal level in the focus area of the video signal created by the video signal and contour correction signal creating means is reduced, and the signal level outside the focus area of the video signal created by the video signal and contour correction signal creating means is left as it is. Thus, a mixed signal of the video signal and the contour correction signal created by the video signal and contour correction signal creation means is created. Thereafter, a luminance signal is created from the mixed signal, and the created luminance signal is supplied to the viewfinder when the focus of the optical lens is adjusted. Thus, since a luminance signal with a signal level reduced only in the focus area can be obtained, it is possible to provide a luminance signal that can be easily focused in focusing of the television camera, and to perform focusing easily. In addition, since a luminance signal is supplied during focus adjustment, the image displayed on the viewfinder becomes a black and white image, the gradation is easy to understand, and the contour portion is also easy to understand. Can do.

  According to the viewfinder display circuit of the second aspect, since the output of the mixer is output at the time of adjusting the focus of the optical lens, the viewfinder is displayed with a video signal with a clear contour correction signal. Thus, there is an effect that a clearer image can be obtained. Further, when it is not during the focus adjustment of the optical lens, the video signal to which the contour correction signal is not added is displayed, so that the video signal is further easily seen.

  According to the viewfinder display circuit of the third aspect, the video signal can be attenuated by 50% by shifting the video signal to the right by the shift register, and the focus area becomes clearer. In the case of a digital video signal, the circuit can be simplified because it can be handled by a 1-bit shift.

  According to the viewfinder display circuit of the fourth aspect, by adjusting the focus of the optical lens to the rotation of the focus ring of the optical lens, it is possible to obtain an adjustment image following the focus operation of the optical lens. In addition, by adjusting the focus of the optical lens when selecting the focus adjustment by the operation item of the TV camera, even if the focus adjustment of the optical lens does not correspond to the rotation of the focus ring of the optical lens, the focus adjustment of the optical lens can be performed. Become useful.

  According to the viewfinder display circuit of the fifth aspect, since the focus area is variable up to the entire screen with reference to the center of the viewfinder screen, it is possible to focus at the optimum position of the subject. A clear image can be obtained.

  According to the viewfinder display circuit of the sixth aspect, when the focus of the optical lens is adjusted, the signal level in the focus area of the luminance signal is reduced and the signal level outside the focus area of the luminance signal is left as it is. Create a mixed signal with the contour correction signal. The mixed signal is supplied to the viewfinder when adjusting the focus of the optical lens. Thus, since a luminance signal with a signal level reduced only in the focus area can be obtained, it is possible to provide a luminance signal that can be easily focused in focusing of the television camera, and to perform focusing easily. In addition, since a luminance signal is supplied during focus adjustment, the image displayed on the viewfinder becomes a black and white image, the gradation is easy to understand, and the contour portion is also easy to understand. Can do.

  According to the viewfinder display circuit of the seventh aspect, since the output of the mixer is output at the time of adjusting the focus of the optical lens, the viewfinder is displayed with a brightness signal having a clear contour correction signal, so that focusing can be easily performed. Thus, there is an effect that a clearer image can be obtained. Further, when not adjusting the focus of the optical lens, since the luminance signal to which the contour correction signal is not added is displayed, the luminance signal is further easily seen.

  According to the viewfinder display circuit of the eighth aspect, the video signal can be attenuated by 50% by shifting the video signal to the right by the shift register, and the focus area becomes clearer. In addition, in the case of a digital video signal, it can be handled by a 1-bit shift, so that the circuit can be simplified.

  According to the viewfinder display circuit of the ninth aspect, by adjusting the focus of the optical lens to the rotation of the focus ring of the optical lens, it is possible to obtain an adjustment image following the focus operation of the optical lens. In addition, by adjusting the focus of the optical lens when selecting the focus adjustment by the operation item of the TV camera, the focus adjustment of the optical lens can be adjusted even when the focus adjustment of the optical lens does not correspond to the rotation of the focus ring of the optical lens. Become useful.

  According to the viewfinder display circuit of the tenth aspect, since the focus area is variable up to the entire screen with reference to the center of the viewfinder screen, it is possible to focus at the optimum position of the subject. A clear image can be obtained.

  According to the viewfinder display method of claim 11, when the focus of the optical lens is adjusted, that is, when the optical lens of the TV camera is manually rotated and the focus adjustment is performed while viewing the output video signal of the TV camera's viewfinder, Reduce the signal level in the focus area of the video signal created in the video signal and contour correction signal creation step, and leave the signal level outside the focus area of the video signal created in the video signal and contour correction signal creation step as it is. Thus, a mixed signal of the video signal and the contour correction signal created in the video signal and contour correction signal creation step is created. Thereafter, a luminance signal is created from the mixed signal, and the created luminance signal is supplied to the viewfinder when the focus of the optical lens is adjusted. Thus, since a luminance signal with a signal level reduced only in the focus area can be obtained, it is possible to provide a luminance signal that can be easily focused in focusing of the television camera, and to perform focusing easily. In addition, since a luminance signal is supplied during focus adjustment, the image displayed on the viewfinder becomes a black and white image, the gradation is easy to understand, and the contour portion is also easy to understand. Can do.

  According to the viewfinder display method of the twelfth aspect, at the time of focus adjustment of the optical lens, the signal level in the focus area of the luminance signal is reduced and the signal level outside the focus area of the luminance signal is left as it is. Create a mixed signal with the contour correction signal. The mixed signal is supplied to the viewfinder when adjusting the focus of the optical lens. Thus, since a luminance signal with a signal level reduced only in the focus area can be obtained, it is possible to provide a luminance signal that can be easily focused in focusing of the television camera, and to perform focusing easily. In addition, since a luminance signal is supplied during focus adjustment, the image displayed on the viewfinder becomes a black and white image, the gradation is easy to understand, and the contour portion is also easy to understand. Can do.

An embodiment of a viewfinder display circuit and method according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of a first embodiment of a viewfinder display circuit according to the present invention. This viewfinder display circuit is used in a three-screen broadcasting television camera, and includes an R channel CCD 101, a G channel CCD 102, a B channel CCD 103, a lens control unit 104, a camera signal processing unit 105, and a focus. An area setting unit 106, VF processing units 107, 108, and 109, a luminance signal creation unit 110, a video switcher 111, and a color VF112 are provided.

  In this embodiment, the color VF 112 constitutes a viewfinder, and the R channel CCD 101, the G channel CCD 102, the B channel CCD 103, and the camera signal processing unit 105 constitute a video signal and contour correction signal creating means, and focus. The area setting unit 106 constitutes a focus area setting unit, the VF processing units 107, 108, and 109 constitute a mixed signal creation unit, the luminance signal creation unit 110 constitutes a luminance signal creation unit, and the lens control unit 104 and The switch 111 constitutes a control means.

  The operation of this embodiment will be described. The R channel CCD 101, the G channel CCD 102, and the B channel CCD 103 each photoelectrically convert an optical signal input through an optical lens (not shown). The camera signal processing unit 105 converts a signal obtained by photoelectrically converting the optical signal into an R-channel video signal RV, a G-channel video signal GV, and a B-channel video signal BV and contour correction. A signal DTL is created. The video signals RV, GV, and BV are output as camera output signals, the video signal RV and the contour correction signal DTL are input to the VF processing unit 107, the video signal GV and the contour correction signal DTL are input to the VF processing unit 108, The video signal BV and the contour correction signal DTL are input to the VF processing unit 109.

  The contour correction signal DTL is generated using a conventional contour correction signal generation circuit (not shown) included in the camera signal processing unit 105. The VF processing units 107, 108, and 109, which will be described in detail later, switch the output of the video signal level and the outline correction signal DTL by the control from the focus area setting unit 106 and the lens control unit 104, and perform output.

  The lens control unit 104 outputs a signal indicating that the optical lens is operating when the focus ring of the optical lens is rotating, that is, a signal indicating the time of focus adjustment. As will be described in detail later, the focus area setting unit 106 sets the focus area with reference to the center portion of the imaging screen, and the size of the focus area can be changed by an external volume (not shown) or the like. it can. Further, the focus area can be changed according to the subject.

  The luminance signal creation unit 110 creates a luminance signal Y from the outputs of the VF processing units 107, 108, and 109. Since the VF processing units 107, 108, and 109 output the R signal, the G signal, and the B signal, respectively, the luminance signal generation unit 110 outputs the signals of the VF processing units 107, 108, and 109 at a predetermined ratio of luminance signal generation. The luminance signal Y is created by mixing.

  The video switcher 111 supplies the luminance signal Y to the color VF 112 when the lens control unit 104 outputs a signal indicating the focus adjustment, and in other cases, the video switching unit 111 outputs the luminance signal Y to the color VF 112. Switching is performed so that the output is supplied to the color VF112.

  FIG. 2 is a block diagram of a second embodiment of the viewfinder display circuit according to the present invention. This viewfinder display circuit is used in a three-screen broadcasting television camera, and includes an R channel CCD 201, a G channel CCD 202, a B channel CCD 203, a lens control unit 204, a camera signal processing unit 205, and a luminance. A signal creation unit 206, a focus area setting unit 207, a VF processing unit 208, a video switcher 209, and a color VF 210 are provided.

  In this embodiment, the color VF 210 constitutes a viewfinder, the R channel CCD 201, the G channel CCD 202, the B channel CCD 203, and the camera signal processing unit 205 constitute a video signal and contour correction signal creating means, and focus. The area setting unit 207 constitutes a focus area setting unit, the luminance signal creation unit 206 constitutes a luminance signal creation unit, the VF processing unit 208 constitutes a mixed signal creation unit, and the lens control unit 204 and the switch 209 include The control means is configured.

  The operation of this embodiment will be described. The configuration and operation of the R channel CCD 201, the G channel CCD 202, the B channel CCD 203, the lens control unit 204, the camera signal processing unit 205, and the focus area setting unit 207 are as follows. This is the same as the CCD 103 for the B channel, the lens control unit 104, the camera signal processing unit 105, and the focus area setting unit 106.

  The luminance signal generation unit 110 generates the luminance signal Y by mixing the video signals RV, GV, and BV, which are the video outputs of the camera signal processing unit 205, at a predetermined ratio of luminance signal generation. As will be described later in detail, the VF processing unit 208 operates under the control of the lens control unit 204 and the focus area setting unit 207 using the luminance signal Y and the contour correction signal DTL as input signals.

  The image switcher 209 supplies the output of the VF processing unit 208 to the color VF 210 when the lens control unit 204 outputs a signal indicating the focus adjustment, and otherwise outputs the output of the camera signal processing unit 205. Switching is performed so that a certain video signal RV, GV, BV is supplied to the color 210.

  FIG. 3 is a block diagram of a third embodiment of a viewfinder display circuit according to the present invention. This viewfinder display circuit is used in a three-screen broadcasting television camera, and includes an R channel CCD 301, a G channel CCD 302, a B channel CCD 303, a lens control unit 304, a camera signal processing unit 305, and a focus. An area setting unit 306, a VF processing unit 307, a video switching unit 308, and a color VF 309 are provided.

  In this embodiment, the color VF 309 constitutes a viewfinder, and the R channel CCD 301, the G channel CCD 302, the B channel CCD 303, and the camera signal processing unit 305 constitute a video signal and contour correction signal creating means for focusing. The area setting unit 306 constitutes a focus area setting unit, the VF processing unit 307 constitutes a mixed signal creation unit, and the lens control unit 304 and the switch 308 constitute a control unit.

  In the first and second embodiments, the luminance signal generated from the RGB signal is input to the color VF directly or through the VF processing unit. However, in this embodiment, the luminance signal is generated. First, processing is performed on one of the RGB signals, and the processed signal is input to the color VF.

  The operation of this embodiment will be described. The configurations and operations of the R channel CCD 301, the G channel CCD 302, the B channel CCD 303, the lens control unit 304, the camera signal processing unit 305, and the focus area setting unit 306 are the same as those of the R channel CCD 101, the G channel CCD 102, FIG. This is the same as the CCD 103 for the B channel, the lens control unit 104, the camera signal processing unit 105, and the focus area setting unit 106.

  As will be described in detail later, the VF processing unit 307 operates under the control of the lens control unit 304 and the focus area setting unit 306 using the video signal GV and the contour correction signal DTL as input signals.

  The video switcher 308 supplies the output of the VF processing unit 307 to the color VF 309 when the lens control unit 204 outputs a signal indicating the focus adjustment, and otherwise outputs the output of the camera signal processing unit 305. Switching is performed so that certain video signals RV, GV, and BV are supplied to the color VF 309.

  When not adjusting the focus of the optical lens, normal video signals RV, GV, and BV are input to the color VF 309. On the other hand, when the focus of the optical lens is adjusted, the output of the VF processing unit 307 is input to the color VF 309 simultaneously for three channels. The GV signal becomes a processed signal when the focus of the optical lens is adjusted, and is output from the VF processing unit 307 as a normal video signal when the focus of the optical lens is not adjusted.

  FIG. 4 is a diagram illustrating the VF processing unit in detail. The VF processing unit includes an attenuator 401, a first switch 402, a mixer 403, and a second switch 404. The video signal obtained from the camera signal processing unit or the luminance signal obtained from the luminance signal creation unit is input to one input unit of the first switch 402. The video signal or the luminance signal is also input to the attenuator 401, attenuated to a predetermined level, and then input to the other input unit of the first switch 402.

  The first switch 402 selects an input attenuated to a predetermined level when the focus of the optical lens is adjusted and the subject is in the focus area, and is not when the focus of the optical lens is adjusted or the subject is out of the focus area. Sometimes, switching is made so that a video signal that does not attenuate is selected.

  The video signal switched by the first switch 402 is directly input to one input unit of the second switch 404, and the contour correction signal DTL is input to the other input unit of the second switch 404 by the mixer 403. The added video signal is input.

  The second switch 404 selects a signal to which the contour correction signal DTL has been added when the focus of the optical lens is being adjusted, and selects a signal to which no contour correction signal DTL has been added when not being the focus adjustment of the optical lens. Output. When the video signal is supplied as a digital signal, the attenuator 401 can attenuate the video signal or the luminance signal by 50% by performing a right shift with a shift register.

  FIG. 5 is a diagram for explaining the focus area of the VF screen. In FIG. 5, the outermost frame represents a VF screen, and the solid line frame at the center of the screen represents a focus area for focusing the optical lens.

  Usually, the photographing is performed so that the portion of the subject to be photographed is in the center of the screen, so the central portion of the screen is set as the focus area. The focus area can be made variable like a dotted line portion and can be expanded to the maximum screen.

  FIG. 6 is a diagram showing a VF screen before and after processing according to the present invention for a part of the screen. By performing processing using the central portion of the screen shown in FIG. 6A as a focus area, the contour correction portion in the frame becomes clear as shown in FIG. 6B.

  When acquiring the contour correction portion as shown in FIG. 6B, a center window for defining the focus area appears with the focus ring of the focus area setting section being turned or while the function button is being pressed as a trigger. The video level is reduced to about 50% (variable), and the video mixed with the normal level contour correction signal is displayed in the center window. As a result, the contour correction signal is emphasized and the focus can be easily set. In addition, ON / OFF of the window marker and the size of the window can be set by operating the television camera.

  FIG. 7 is a diagram showing a VF screen before and after processing according to the present invention for the entire screen. By performing the process using the entire screen shown in FIG. 7A as the focus area, the entire screen becomes clear as shown in FIG. 7B.

The present invention is not limited to the above-described embodiment, and many changes and modifications can be made.
For example, in the above first to third embodiments, the case where the viewfinder display circuit and method are used for a three-broadcast television camera has been described. However, the viewfinder display circuit and method according to the present invention is a single-plate broadcast. It can also be used for television cameras.

  In the first to third embodiments, when the focus of the optical lens is adjusted, the lens control unit outputs the focus. However, when there is no output from the lens control unit, the focus adjustment is performed as an operation item of the television camera. It is also possible to provide such that the output during the focus adjustment of the optical lens is output from the television camera body.

  In the third embodiment, the VF processing is performed on the G channel. However, similar processing can be performed on other R channels or B channels.

  INDUSTRIAL APPLICABILITY The present invention is useful for a broadcast television camera that manually rotates an optical lens and adjusts the focus of the optical lens while viewing an output video signal of a viewfinder. The present invention is also useful for a television camera that performs contour correction. Even when the luminance level of a video signal is high and the contour correction portion is difficult to see, a focus adjustment item is provided and a captured image is viewed on a viewfinder or a monitor TV. By carrying out the present invention when focusing as described above, the focus adjustment of the optical lens becomes smooth.

1 is a block diagram of a first embodiment of a viewfinder display circuit according to the present invention. FIG. It is a block diagram of 2nd Embodiment of the viewfinder display circuit by this invention. It is a block diagram of 3rd Embodiment of the viewfinder display circuit by this invention. It is a figure which shows a VF process part in detail. It is a figure for demonstrating the focus area of a VF screen. It is a figure which shows the VF screen before and behind the process by this invention about a part of screen. It is a figure which shows the VF screen before and behind the process by this invention about the whole screen. It is a block diagram of a conventional viewfinder display circuit.

Explanation of symbols

101, 201, 301 R channel CCD
102, 202, 302 G channel CCD
103, 203, 303 B channel CCD
104, 204, 304 Lens control unit 105, 205, 305 Camera signal processing unit 106, 207, 306 Focus area setting unit 107, 108, 109, 208, 307 VF processing unit 110, 206 Luminance signal generation unit 111, 209, 308 Video switcher 112, 210, 309 Color VF
401 Attenuator 402 First switch 403 Mixer 404 Second switch

Claims (12)

A viewfinder that displays video signals to adjust the focus of the optical lens of the TV camera;
A video signal and a contour correction signal creating means for creating a video signal and a contour correction signal from the optical signal input through the optical lens;
A focus area setting means for setting a focus area in the viewfinder screen;
At the time of focus adjustment of the optical lens, the signal level in the focus area of the video signal created by the video signal and the contour correction signal creating unit is reduced and the video created by the video signal and the contour correction signal creating unit Mixed signal creating means for creating a mixed signal of the video signal and the contour correction signal created by the video signal and the contour correction signal creating means while leaving the signal level outside the focus area of the signal;
A luminance signal creating means for creating a luminance signal from the mixed signal;
A viewfinder display circuit comprising: control means for controlling the luminance signal to be supplied to the viewfinder during focus adjustment of the optical lens. The mixed signal generating means is
An attenuator for attenuating the video signal created by the video signal and the contour correction signal creating means;
A first input unit to which the video signal created by the video signal and the contour correction signal creation unit is input and a second input unit to which the video signal attenuated by the attenuator is input, and the focal point of the optical lens When the adjustment is performed and the subject is within the focus area, the video signal attenuated by the attenuator is output. When the focus of the optical lens is not adjusted or the subject is outside the focus area, the video signal and the contour are output. A first switch for switching so as to output the video signal created by the correction signal creating means;
A mixer for mixing the output of the first switch and the contour correction signal;
A first input unit to which an output of the first switch is input and a second input unit to which an output of the mixer is input; and when the focus of the optical lens is adjusted, the output of the mixer is output; 2. The viewfinder display circuit according to claim 1, further comprising a second switch for switching so as to output the output of the first switch when not adjusting the focus of the optical lens.   3. The viewfinder display circuit according to claim 2, wherein the video signal is a digital video signal, and the attenuator is a shift register.   4. The method according to claim 1, wherein the focus adjustment of the optical lens is performed when a focus ring of the optical lens is rotated or when focus adjustment is selected by an operation item of the television camera. 5. The viewfinder display circuit described.   5. The viewfinder display circuit according to claim 1, wherein the focus area is variable from the center of the viewfinder screen to the entire screen. A viewfinder that displays video signals to adjust the focus of the optical lens of the TV camera;
A video signal and a contour correction signal creating means for creating a video signal and a contour correction signal from the optical signal input through the optical lens;
A focus area setting means for setting a focus area in the viewfinder screen;
A luminance signal creating means for creating a luminance signal from the video signal;
At the time of focus adjustment of the optical lens, the signal level of the luminance signal in the focus area is reduced, and the signal level of the luminance signal outside the focus area is left as it is. A mixed signal creating means for creating a mixed signal;
A viewfinder display circuit comprising: control means for controlling the mixed signal to be supplied to the viewfinder when the focus of the optical lens is adjusted. The mixed signal generating means is
An attenuator for attenuating the luminance signal created by the luminance signal creating means;
When the focus of the optical lens is adjusted, the first input unit to which the luminance signal generated by the luminance signal generation unit is input and the second input unit to which the luminance signal attenuated by the attenuator is input. The luminance signal attenuated by the attenuator is output when the subject is in the focus area, and is generated by the luminance signal generating means when the focus of the optical lens is not adjusted or when the subject is outside the focus area. A first switch for switching to output a luminance signal;
A mixer for mixing the output of the first switch and the contour correction signal;
A first input unit to which an output of the first switch is input and a second input unit to which an output of the mixer is input; and when the focus of the optical lens is adjusted, the output of the mixer is output; 7. The viewfinder display circuit according to claim 6, further comprising a second switch for switching so as to output the output of the first switch when not adjusting the focus of the optical lens.   8. The viewfinder display circuit according to claim 7, wherein the video signal is a digital video signal, and the attenuator is a shift register.   9. The method according to claim 6, wherein the focus adjustment of the optical lens is performed when the focus ring of the optical lens is rotated or when focus adjustment is selected by an operation item of the television camera. The viewfinder display circuit described.   10. The viewfinder display circuit according to claim 6, wherein the focus area is variable from the center of the viewfinder screen to the entire screen. A video signal and contour correction signal creating step for creating a video signal and contour correction signal from an optical signal input through an optical lens of a television camera;
A focus area setting step for setting a focus area in a viewfinder screen on which a video signal is projected to adjust the focus of the optical lens;
When adjusting the focus of the optical lens, the signal level in the focus area of the video signal created in the video signal and contour correction signal creation step is reduced, and the video created in the video signal and contour correction signal creation step A mixed signal creating step for creating a mixed signal of the video signal and the contour correction signal created in the video signal and the contour correction signal creating step while leaving the signal level outside the focus area of the signal;
A luminance signal creating step of creating a luminance signal from the mixed signal;
And a control step for controlling the luminance signal to be supplied to the viewfinder at the time of adjusting the focus of the optical lens. A video signal and contour correction signal generation step for generating a video signal and a contour correction signal from an optical signal input through an optical lens of a television camera;
A focus area setting step for setting a focus area in a viewfinder screen on which a video signal is projected to adjust the focus of the optical lens;
A luminance signal creating step of creating a luminance signal from the video signal;
At the time of focus adjustment of the optical lens, the signal level of the luminance signal in the focus area is reduced, and the signal level of the luminance signal outside the focus area is left as it is. A mixed signal creation step for creating a mixed signal;
And a control step of controlling the mixed signal to be supplied to the viewfinder when adjusting the focus of the optical lens.