JPH0215427Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a video tape recorder equipped with a novel video camera, and in particular, to a video camera and an auto white balance circuit for automatically taking the white balance of the video camera. , relates to a video tape recorder equipped with a video camera that integrally includes an auto white balance switch that starts the operation of the auto white balance circuit, and a recording section that records the output of the video camera; A videotape equipped with a new video camera that prevents the auto white balance circuit from accidentally touching the auto white balance switch or otherwise causing a distorted image to be recorded. It is intended to provide a recorder.

Background technology and its problems Some video cameras are equipped with an auto white balance function. Auto white balance automatically adjusts so that when a white subject looks red or blue due to the lighting, it will appear white. If you take a picture at full screen and operate the white balance switch in that state, the white balance will be automatically adjusted.

By the way, this white balance should generally be done before starting shooting, but if you accidentally operate or touch the white balance switch during shooting, the auto white balance circuit will adjust the white balance. Sometimes I end up doing this. When the auto white balance circuit performs a white balance operation, color shift occurs for one to several seconds, resulting in an extremely unsightly image. Furthermore, since portable video tape recorders that combine a video camera and recording device are often used by amateur photographers, there is a risk of accidentally operating the white balance switch, and the white balance switch is designed to be easy to operate. It is often located on the left side of the video tape recorder when viewed from the back, making it easy to touch. Therefore, if you accidentally touch the auto white balance switch while recording, the white balance circuit will take action to adjust the white balance, resulting in a hard-to-read image with color shift, which will significantly reduce the value of your video work. The possibility of this happening cannot be ignored.

Purpose of the Invention The present invention provides a video camera, an auto white balance circuit for automatically adjusting the white balance of the video camera, an auto white balance switch for starting the operation of the auto white balance circuit, and an auto white balance switch for starting the operation of the auto white balance circuit. In a video tape recorder equipped with a video camera that integrally includes a recording unit that records the output of the video camera,
If you accidentally operate the auto white balance switch or touch it during recording, the white balance circuit will take action to correct the white balance, which will prevent you from recording an image that is difficult to see with color misalignment. The purpose is to

Summary of the invention In order to achieve the above object, the video tape recorder equipped with the video camera of the invention includes a video camera, an auto white balance circuit for automatically taking the white balance of the video camera, and the auto white balance circuit. A video tape recorder equipped with a video camera that integrally includes an auto white balance switch that starts the operation of the video camera, and a recording section that records the output of the video camera, wherein the recording section is performing a recording operation. The present invention is characterized in that a prohibition means is provided for prohibiting the white balance operation of the auto white balance circuit.

Embodiments Hereinafter, a video tape recorder equipped with a video camera of the present invention will be described in detail according to embodiments shown in the accompanying drawings. FIG. 1 is a circuit block diagram showing the main parts of an embodiment of a video tape recorder equipped with a video camera of the present invention. In the drawing, 1
is an image pickup tube, 2 is an aperture, 3 is a preamplifier that amplifies the video signal output from the image pickup tube 1, and 4 is an average value or a peak value of the output signal of the preamplifier 3, and the aperture 2 is controlled according to that value. It is an iris controller. Note that if the amount of light is a constant value (for example,
100 lux) or less, a low light signal Sl1 is sent from the iris controller 4 to a system controller to be described later.
5 is an auto gain controller that automatically controls the gain according to the magnitude of the average value of the video signal; 6
is a low-pass filter that passes the luminance signal Y, and plays the role of extracting the luminance signal Y from the video signal output from the auto gain controller 5. 7 is a synchronizing signal to the luminance signal Y that has passed through the low pass filter 6
This is a sync signal mixing circuit that mixes Sync, and the output of the sync signal mixing circuit 7 is sent to the pre-emphasis circuit 8.
The signal is input to the FM modulator 9 via the FM modulator 9. The signal FM modulated by the FM modulator 9 is amplified by a luminance signal recording amplifier 10 and sent to an adder circuit 11.

12 is a color difference signal decoder that generates color difference signals R-Y and BY from the output signal of the auto gain controller 5; 13 is a white balance circuit that processes the color difference signals R-Y and BY to automatically perform white balance. It is. This white balance is used to ensure that when an object that is white under sunlight becomes more reddish or bluish due to differences in illumination light, the object will be reproduced as white. When the white balance switch 14 is pressed while a white subject is being photographed, a white balance command signal Swhi is received and the white balance is automatically adjusted. Specifically, the color signals R, G, and B are extracted from the color difference signals R-Y and B-Y, the color tendency of the light from the subject is memorized, and the color difference is adjusted so that the subject appears white according to that tendency. Signal R-Y, B-Y
Achieve the state of adjusting the level.

15 is an encoder, white balance circuit 1
The color difference signals R-Y and B-Y output from 3 are used to amplitude-modulate the subcarriers Sc whose phases are different from each other by 90 degrees,
The two amplitude modulated signals are added together. A chroma signal recording amplifier 16 amplifies the modulated color signal output from the encoder 15, and this output signal is sent to the adder circuit 11. Then, in the adding circuit 11, the luminance signal from the luminance signal recording amplifier 10 and the chroma signal from the chroma signal recording amplifier 16 are added, and the output signal of the adding circuit 11 is sent to the video head 17.

Reference numeral 18 denotes a white balance prohibition switch connected in series with the white balance switch 14, which is controlled by the system controller 19 and is not manually operated. Therefore, it is not exposed to the outside. 20 is a recording switch, and when this is turned on, recording starts. When the recording switch 20 is turned on and the video tape recorder is in the recording state, or when receiving the low light signal Sll from the iris controller 4, the system controller 19 sends a white balance prohibition signal Sinh to the white balance prohibition switch 18. Send. The white balance prohibition switch 18 is configured to turn off when it receives the white balance prohibition signal Sinh, and to turn on when it does not receive the white balance prohibition signal Sinh.

FIG. 2 is a perspective view of a video tape recorder, and the circuit shown in FIG. 1 is built into this video tape recorder. The white balance switch 14 is arranged at the front of the left side of the video tape recorder main body 21 when viewed from the rear side, along with the autofocus switch 22. This video tape recorder consists of two video tape recorder bodies.
The user grasps the grip 23 provided on the bottom of the lens with his right hand, places his eye on the eyecup 24, looks through the viewfinder 25, and uses his left hand to perform zooming, aperture adjustment, and other operations while taking pictures. There is a possibility that the white balance switch 14 may be touched by mistake when the user moves his left hand to operate the lens unit 26 in order to do so. However, in this video tape recorder, the white balance prohibition switch 18 remains off during recording, and even if the white balance switch 14 is pushed, the white balance command signal Swhi instructs the white balance circuit 13 to perform a white balance operation. cannot be entered.

Therefore, the white balance switch 1 must be set during recording.
Even if 4 is pressed by mistake, there is no risk of color misregistration, and there is no risk of recording an image that is extremely difficult to see.

Effects of the Invention As stated above, the video tape recorder equipped with the video camera of the present invention includes a video camera,
An auto white balance circuit for automatically taking the white balance of the video camera, an auto white balance switch for starting the operation of the auto white balance circuit, and a recording section for recording the output of the video camera are integrated. A video tape recorder equipped with a video camera having a video camera, characterized in that a prohibition means is provided for prohibiting the white balance operation of the auto white balance circuit when the recording section is performing a recording operation. It is something.

Therefore, with the tape recorder equipped with the video camera of the present invention, there is no fear that the auto white balance circuit performs a white balance operation during recording, resulting in a hard-to-see image with color shift being recorded. be able to.

[Brief explanation of drawings]

1 and 2 show an example of implementation of a video tape recorder equipped with a video camera of the present invention. FIG. 1 is a circuit block diagram showing the main parts, and FIG. 2 is a perspective view of the video tape recorder. be. Explanation of symbols, 1 to 4...Video camera, 13...
...Auto white balance circuit, 14...Auto white balance switch, 17...Recording section, 1
8, 19, 20... Prohibition means for prohibiting the operation of taking white balance.

Claims (1)

[Scope of utility model registration request] a video camera; an auto white balance circuit for automatically adjusting the white balance of the video camera; an auto white balance switch for starting the operation of the auto white balance circuit; and a recording section for recording the output of the video camera. , wherein the video tape recorder is equipped with a video camera that integrally has a video camera, and is provided with a prohibition means for prohibiting the white balance operation of the auto white balance circuit when the recording section is performing a recording operation. A videotape recorder equipped with a video camera characterized by: