JPH10319307A - Video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm a distance to a position which is in a focusing condition by a focus adjusting means even though the line of sight is averted from an image display means. SOLUTION: A microprocessor 18 arithmetically calculates distance data from a video camera which is in the focusing condition and can perform photographig of a subject based on the absolute position data of a focusing ring 4 detected by a potentiometer 9. The microprocessor 18 converts the distance data into character data 20, and writes the data into a character signal generator 19. The generator 19 outputs a character signal 22 and a border signal 23 in accordance with the written data 20. The signals are displayed on a view finder 2 with a subject image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera provided with image display means for displaying a photographed image.

[0002]

2. Description of the Related Art Generally, a video camera for capturing a moving image is provided with, for example, a viewfinder as image display means for displaying a captured image. The user shoots a target subject while viewing the shot image displayed by the viewfinder.

[0003] Commercial video cameras used in news gathering are used with the camera body resting on the shoulders of the user. For this reason, the viewfinder of this professional video camera is arranged such that the eyepiece is located at the position of the user's eye when the camera body is placed on the shoulder of the user.

A lens portion of a professional video camera has a focus ring for manually driving a focus lens as a focus adjusting means for focusing, and a user looks at a viewfinder. The focus ring is adjusted by rotating the focus ring so that the image on the viewfinder is in an appropriate focus state, that is, a focused state. A scale corresponding to the distance is engraved on the focus ring. When the distance from the video camera to the subject is known, the user can roughly adjust the focus by adjusting the distance scale of the focus ring to the corresponding distance.

[0005]

However, when the user rotates the focus ring to adjust the scale, the user must remove his / her line of sight from the viewfinder to see the scale engraved on the focus ring. However, there is a problem that the photographing operation is temporarily interrupted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a video camera in which an image display means is provided integrally with a camera body, without having to remove a line of sight from the image display means. It is an object of the present invention to provide a video camera capable of confirming a distance to a position brought into a focused state by adjusting means.

[0007]

SUMMARY OF THE INVENTION A video camera according to the present invention has an optical system for forming an image of a subject, a photographing means for photographing the subject, and a photographing means for photographing the subject by the photographing means. An image display unit for displaying an image, a focus adjustment unit for driving an optical system in the imaging unit to adjust a distance to a subject that can be imaged in a state where the imaging unit is in focus, and a focus adjustment unit for Detecting means for detecting a state; distance information generating means for generating information on a distance to a subject which can be photographed in a focused state by the photographing means based on a detection output of the detecting means; And distance information display control means for displaying the obtained information using the image display means.

In the video camera of the present invention, the optical system in the photographing means is driven by the focus adjusting means, and the distance to the subject to which the photographing means can photograph in the focused state is adjusted. At this time, the state of the focus adjusting means is detected by the detecting means, and the distance information generating means obtains information on the distance to the subject which can be photographed in the focused state by the photographing means based on the detection output of the detecting means. Generated.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 2 is a side view showing an appearance of a video camera according to a first embodiment of the present invention. The video camera 1 is connected to a camera body 1a, a front end portion of the camera body 1a, a lens unit 3 for capturing a subject image, and an image provided on an upper part of the camera body 1a for displaying a captured image. And a viewfinder 2 as display means. The viewfinder 2 has a CRT (cathode ray tube) or a liquid crystal display device, and an eyepiece pad 7 is provided at the tip of the viewfinder 2 for a user to contact around the eyes when viewing the viewfinder 2. ing. The lens unit 3 has a focus ring 4 for adjusting a focus as a focus adjusting unit. The camera body 1a is provided with a lens connector 6, and the lens unit 3 is electrically connected via the lens cable 5 and the lens connector 6.

FIG. 3 is an explanatory diagram showing the internal configuration of the lens unit 3. The lens unit 3 includes a focus lens 31 for adjusting a focus, a zoom lens 32 for performing zooming, and a stop 33 for adjusting the amount of light. A focusing lens driving unit 34 that drives the focusing lens 31 is provided below the focusing lens 31. Focusing lens driving unit 34 based on the control signal S ₀₁ output from the camera main body 1a,
While moving the focus lens 31 to a position fit focus, and outputs a focus position signals S ₁ representing the focus position information corresponding to the position of the focusing lens 31. Further, a zoom lens driving unit 35 that drives the zoom lens 32 is provided below the zoom lens 32. Zoom lens driving unit 35, based on a control signal S ₀₂ output from the camera main body 1a, thereby moving the zoom lens 32, a zoom position signal S ₂ representative of the position data of the zoom lens 32
Is output. Further, an aperture driving unit 36 that opens and closes the aperture 33 is provided below the aperture 33. With diaphragm driver 36, based on the control signal S ₀₃ output from the camera main body 1a, drives the aperture 33,
And outputs a position signal S ₃ stop such opening data of the throttle 33. The control signals S ₀₁ , S ₀₂ , S
₀₃ is sent from the camera body 1a to each of the driving units 34, 35, 36 via the lens connector 6 and the lens cable 5. Further, each of the driving units 34, 35,
The position signals S ₁ , S ₂ , and S ₃ from the camera body 1 a are transmitted via the lens cable 5 and the lens connector 6.
To be sent to

FIG. 4 shows the focus ring 4 shown in FIG.
Is enlarged. Focus ring 4
The lens barrel 3 of the lens unit 3 is used for adjusting the focus by manually driving the focusing lens 31.
Is provided at the tip of the camera. A scale 42 is engraved on the focus ring 4, and an index line 43 is provided on the boundary tube 41. When manually adjusting the focus, the user turns the focus ring 4 to adjust the focus, and when the focus is achieved, the focus ring 4 is adjusted.
Stop the rotation of. At this time, the numerical value of the scale 42 at the position of the index line 43 (about 2.2 m in FIG. 4) is the distance to the subject that can be photographed in the focused state. When the user knows the distance to the subject in advance, the user can turn the focus ring 4 and adjust the numerical value of the desired distance on the scale 42 to the index line 43 to roughly adjust the focus. .

FIG. 1 is a block diagram showing a configuration of a video camera 1 according to the present embodiment. This video camera 1
Is a spectral prism system 12 that splits incident light from the focusing lens 31 into three color lights of R (red) light, G (green) light, and B (blue) light, for example, a dichroic mirror, and a light from the spectral prism system 12. Image sensors 13R, 13G, which receive R light, G light, and B light, respectively, and perform photoelectric conversion.
13B and the R, G, and B signals from the imaging devices 13R, 13G, and 13B are converted into amplifiers 28R, 28G, and 28B.
, A luminance signal (Y) and a color difference signal (RY, BY) are generated based on these signals, a monitor signal 17 for displaying a captured image on the viewfinder 2, and a monitor signal 17. A signal processing circuit 14 for generating a test signal for monitoring the signal, the G signal, and the B signal; a color encoder 15 for receiving a luminance signal and a color difference signal from the signal processing circuit 14 and generating a composite video signal 16; , The composite video signal 16 to the amplifier 3
8a and a video out terminal 8 for receiving the signal via the resistor 37 and outputting the received signal to the outside.

The video camera 1 also includes a signal processing circuit 1
A signal changeover switch 39 for switching between a monitor signal 17 (for example, a black-and-white signal) or a test signal and a character signal for displaying the distance to the subject, and a signal passing through the signal changeover switch 39 Viewfinder 2 receiving via amplifier 38b
And

The focusing lens driving unit 34 in the lens unit 3 of the video camera 1
And a potentiometer 9 for detecting the absolute position of the focus ring 4 as a detecting means.

The video camera 1 further includes a drive circuit 27 for driving a focus motor 34a, and a microprocessor 1 for controlling the entire system of the video camera 1.
8 and a dedicated processor 26 that outputs a focus position signal S ₁ input to the lens connector 6 in response to a request from the microprocessor 18.

The microprocessor 18, the autofocus operation, the control signals S _0, the drive circuit 27
Is controlled to drive the focus motor 34a to bring it into a focused state. Potentiometer 9 is
The focus position signal S ₁ representing the absolute position of the focus ring 4 is output to the lens connector 6. Focus position signal S ₁ input to the lens connector 6 is outputted to the dedicated processor 26, in response to a request of the microprocessor 18, and is output to the microprocessor 18. Microprocessor 18
Calculates distance data to a subject that can be photographed in a focused state based on the focus position signal S ₁ , generates character data 20 representing the distance data, It is output together with a clock 21.

The video camera 1 also generates a character signal 22 and a border signal 23 representing the boundary of the character based on the character data 20 and the clock 21 output from the microprocessor 18, and outputs the character signal. 19, a switch 24 for switching on / off the character signal 22 from the character signal generator 19 based on the viewfinder character control signal 29, and an on / off switch for the border signal 23 in the same manner as the character signal 22. And a changeover switch 25.

Next, main operations of the video camera 1 according to the present embodiment shown in FIG. 1 will be described. In the video camera 1, first, the light that has passed through the lens unit 3 is split into three colors of R light, B light, and G light by the spectral prism system 12. The R light, the B light, and the G light are respectively transmitted to the
The signals are photoelectrically converted by 3B and 13G to become an R signal, a G signal, and a B signal. The R signal, the G signal, and the B signal are amplified by the amplifiers 28R, 28G, and 28B, respectively, and output to the signal processing circuit 14. The signal processing circuit 14 generates a luminance signal (Y) and a color difference signal (R
−Y, BY) and outputs it to the color encoder 15. The color encoder 15 generates a composite video signal 16 based on the input luminance signal and color difference signal, and outputs the composite video signal 16 to the video-out terminal 8 via an amplifier 38a and a resistor 37 of, for example, 75Ω. On the other hand, from the signal processing circuit 14, a monitor signal 17 or a test signal for the viewfinder 2 is obtained in addition to the luminance signal and the color difference signal. When the fixed contact 39a provided on the signal processing circuit 14 side and the movable contact 39d provided on the viewfinder 2 side are connected by the signal changeover switch 39, the monitor signal 17 is transmitted through the amplifier 38b. It is output to the finder 2 and displayed. In this way, the photographed subject image is displayed on the viewfinder 2.

In the present embodiment, it is possible to display the distance to a subject that can be photographed in focus with the viewfinder 2 together with the subject image. Therefore, in addition to the monitor signal 17 of the subject image described above, a signal for displaying the distance to the subject is transmitted to the viewfinder 2.
Output to The signal for displaying this distance and the monitor signal 17 are provided by a microprocessor 18
Is switched by the signal changeover switch 39 on the basis of the changeover control signal S _A.

Here, the distance from the video camera 1 which can be photographed in the focused state to the subject is obtained as follows. First, the potentiometer 9 is attached to the focus ring 4
Detecting the angular position, it outputs a focus position signals S ₁ corresponding to the angular position. Focus position signal S
₁ is output to the dedicated processor 26 as, for example, an analog value via the lens cable 5 and the lens connector 6. The dedicated processor 26 converts the input focus position signal S ₁ from an analog value to a digital value (AD
Conversion), and outputs the result to the microprocessor 18 in response to a request from the microprocessor 18. The microprocessor 18 calculates distance data to a subject that can be photographed in a focused state based on the input data, and converts the distance data into character data 20 corresponding to various display characters and symbols. , And writes them to the character signal generator 19 in synchronization with the clock 21. Character signal generator 19
Outputs a character signal 22 and a border signal 23 for displaying distance information to a subject by characters and symbols in accordance with the written character data 20.

FIG. 5 shows a character signal 22 and a border signal 23 when displaying a character. For example, a character "A" is displayed on the viewfinder 2 by a character signal 22 and a border signal 23 representing the character. The border signal 23 is a signal for indicating a boundary between the character portion displayed by the character signal 22 and another portion. The border signal 23 makes the character display clearer.

The character signal 22 and the border signal 23 output from the character signal generator 19 are respectively
Based on a viewfinder character control signal 29 indicating ON / OFF of display of a character on the viewfinder 2 input from an operation switch (not shown), fixed contacts 39b and 39c of a signal changeover switch 39 are operated by changeover switches 24 and 25. It is switched whether or not the input is made. On the other hand, the signal changeover switch 39, based on a switching control signal S _A from the microprocessor 18, monitor signal 17, and outputs the switched character signal 22 and a border signal 23. When the movable contact 39d and the fixed contact 39a are connected, the signal changeover switch 39 is a monitor signal 17 for displaying a subject image.
Through. The signal changeover switch 39 allows the character signal 22 to pass when the movable contact 39d and the fixed contact 39b are connected. Further, the signal changeover switch 39 allows the border signal 23 to pass when the movable contact 39d and the fixed contact 39c are connected. The signals passing through the signal changeover switches 39 are respectively supplied to the amplifiers 3
8b is displayed on the viewfinder 2. For example, when the viewfinder character control signal 29 is turned on, the monitor signal 17, the character signal 22, and the border signal 2
3 is instantaneously performed, and as shown in FIG. 6, focus position information 61 (in FIG. 6) for indicating the distance to the subject that can be photographed in the focused state by characters and symbols on the viewfinder screen 60. 2.2m) is synthesized with the subject image and displayed.

As described above, according to the video camera 1 according to the present embodiment, focus position information, that is, information on the distance to a subject that can be photographed in a focused state is displayed on the viewfinder 2 as characters and symbols together with the subject image. Since the display is performed, the user can look at the display of the character on the screen of the view finder 2 without focusing on the distance finder of the focus ring 4 by looking away from the view finder 2 to obtain a focused state. It is possible to check information on the distance to a photographable subject.

Further, for example, by increasing the resolution of the focus position information detected by the potentiometer 9, it is possible to display a distance finer than the distance scale on the focus ring 4, so that it is possible to accurately reach the subject in focus. You can know the distance.

Furthermore, whether or not the focus position information is displayed on the viewfinder 2 can be controlled by the changeover switches 24 and 25 based on the viewfinder character control signal 29. The user can determine whether to display the focus position information on / off according to the necessity of confirming the distance information to the subject while looking at the screen, thereby increasing the degree of freedom of work.

[Second Embodiment] FIG. 7 is a block diagram showing a configuration of a video camera according to a second embodiment of the present invention. In the video camera according to the present embodiment, a character signal representing the focus position information, a border signal, and a monitor signal of the subject image are all added to form a composite image, which is then output to a viewfinder. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The video camera according to the present embodiment includes a character adder 70 instead of the signal changeover switch 39 in the video camera 1 according to the first embodiment. The character adder 70 adds the character signal 22 and the border signal 23 that are turned on by the changeover switches 24 and 25 to be input, and the monitor signal 17 from the signal processing circuit 14 to generate a combined image signal, and outputs the combined image signal via the amplifier 38b. Output to the viewfinder 2.

Next, main operations of the video camera according to the present embodiment will be described. When the viewfinder character control signal 29 turns on the display of the character on the viewfinder 2, the changeover switches 24 and 25 are turned on and the character signal 22 and the border signal 23 are input to the character adder 70. The character adder 70 adds the monitor signal 17, the character signal 22, and the border signal 23 input from the signal processing circuit 14, and generates a synthesized image signal in which a character representing the subject image and the focus position information is synthesized, and the amplifier 3
The composite image is output to the viewfinder 2 via the display 8b.

Other configurations, operations and effects in the present embodiment are the same as those in the first embodiment.

[0031] The present invention is not limited to the foregoing embodiments, for example, in the above embodiment, the focus position signal S ₁ output from the lens connector 6 to the dedicated processor 26 has been set to analog signals , Analog signals and digital signals can be applied. When a digital signal is used, it can be encoded in advance by the lens unit 3.

In each of the above embodiments, the dedicated processor 26 responds to a request from the microprocessor 18 to
Although the focus position information has been output to the microprocessor 18, the dedicated processor 26 may be omitted. In this case, the processing of the focus position information is directly performed by the microprocessor 18.

Further, the display format of the focus position information on the viewfinder 2 may be a numerical display in meters or a numerical display in feet, or a bar display using segments instead of numerical display.

The video camera according to the present invention is applicable to both an auto-focus video camera for automatically focusing on a subject and a manual video camera for manually focusing. When used in an autofocus video camera, information generated by the distance information generating means can be used as auxiliary information for determining a focused distance.

[0035]

As described above, claims 1 to 4
According to the video camera described in any of the above, the state of the focus adjustment means is detected, and based on the detection output, information on the distance to a subject that can be photographed in a focused state is generated, and this information is displayed as an image. Since the information is displayed by the means, the user can confirm the distance to the subject without taking his / her eyes off the image display means, and the effect of improving the work efficiency of photographing can be obtained.

Further, according to the video camera of the present invention, it is determined whether or not the distance to the object which can be photographed in the focused state is displayed on the image display means based on an arbitrarily set control signal. Since the user can control the distance, the user can determine whether to display the distance on or off according to the necessity of confirming the distance to the subject while watching the screen displayed on the image display means. This has the effect of increasing the degree of freedom of work.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video camera according to a first embodiment of the present invention.

FIG. 2 is a side view of the video camera according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for describing an internal configuration of a lens unit of the video camera in FIG. 2;

FIG. 4 is an enlarged view for explaining a focus ring of the video camera of FIG. 2;

FIG. 5 is an explanatory diagram for explaining a character signal and a border signal.

FIG. 6 is an explanatory diagram for explaining a display mode on a viewfinder screen.

FIG. 7 is a block diagram showing a configuration of a video camera according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Video camera, 2 ... Viewfinder, 3 ... Lens part, 4 ... Focus ring, 5 ... Lens cable, 6 ...
Lens connector, 9 potentiometer, 12 spectral prism system, 13R, 13G, 13B image sensor, 14
Signal processing circuit, 18 microprocessor, 19 character signal generator, 24, 25 switch, 2
6: dedicated processor, 29: viewfinder character control signal, 31: focus lens, 34a: focus motor, 39: signal switch.

Claims (4)

[Claims] A photographing means for photographing a subject; an image display means for displaying an image of the subject photographed by the photographing means; A focus adjustment unit for driving the optical system in the imaging unit to adjust a distance to a subject that can be imaged in the in-focus state by the imaging unit; a detection unit that detects a state of the focus adjustment unit; Distance information generating means for generating information on a distance to a subject which can be photographed by the photographing means in a focused state based on the detection output of the detecting means; and information generated by the distance information generating means, A video camera, comprising: distance information display control means for displaying using a display means. 2. The video camera according to claim 1, wherein the distance information generating means generates a signal for displaying the distance information by characters and symbols. 3. The video camera according to claim 1, wherein the distance information display control means can select whether or not to display the distance information. 4. The distance information display control means combines the image of the subject and an image indicating the information of the distance, and displays the combined image using the image display means. The video camera according to claim 1.