JPH05276431A - Video camera - Google Patents

Abstract

(57) [Summary] [Object] To provide a video camera capable of obtaining a multiple-exposure still image separately from a moving image while recording the moving image. [Arrangement] An arithmetic circuit 8 to which an input video signal is supplied and a frame memory 9 for storing the output signal are provided. The output of the frame memory 9 is fed back to the arithmetic circuit 8 to obtain the feedback amount and the frame memory 9. The control circuit 10 controls writing and reading of the data. When the control circuit 10 takes in a total of N video signals at a rate of once on the M screen,
When the input video signal amount is K and the feedback amount is 1-K, control is performed to set K = 1, 1/2, 1/3, ..., 1 / N at M screen intervals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera capable of producing a multiple exposure still image.

[0002]

2. Description of the Related Art In order to realize a multiple exposure still image with a video camera, means for applying V reset of a CCD (solid-state image sensor) and means for providing a mechanical shutter are considered.

However, in the above means, since the image pickup signal itself outputted from the CCD is operated, there is a drawback that a still image of multiple exposure cannot be taken in while recording a moving image.

Therefore, an object of the present invention is to provide a video camera capable of obtaining a still image with a large amount of exposure even while recording a moving image.

[0005]

In order to achieve the above object, the video camera of the present invention is provided with a memory capable of storing a video signal for one screen, and supplies the output of an arithmetic circuit to this memory. An input video signal and a feedback signal from the memory are respectively supplied to the circuit, and a control circuit capable of controlling writing and reading of the memory and a feedback amount to the arithmetic circuit is provided, and the input video signal is supplied a plurality of times. The amount of feedback from the memory is controlled while being taken into the memory.

Further, when the control circuit fetches N video signals at a rate of once per M screens, M is required.
A video signal for one screen is taken into the memory at screen intervals, and the input video signal amount to the arithmetic circuit is K and the feedback amount is 1
Assuming −K, the control is performed so that K = 1, 1/2, 1/3, ..., 1 / N.

[0007]

Therefore, during recording of a moving image, a video signal of the moving image is guided to an arithmetic circuit and a memory, and the amount of feedback to the arithmetic circuit and the reading and writing of the memory are controlled to obtain a multiple-exposure still image. .. Also, the control circuit is K = 1,1
By controlling / 2, 1/3, ..., 1 / N, it is possible to obtain a multiple exposure still image image in which N still images have a uniform exposure amount.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an example in which the present invention is applied to a video camera of a standard called 8 mm video.

According to this standard, recording and reproduction are performed using a pair of rotary heads provided at an angular interval of 180 degrees with each other, and the tape is wound within a range of 221 degrees of the head rotation peripheral surface. And one of these 221 degrees
Recording and reproduction of the video signal is performed in the section of 80 degrees,
Recording and reproduction of a digital (PCM) and time-axis-compressed audio signal are performed in the remaining 36 degrees.

FIG. 4 shows a recording format on the tape 1. 4, the track T is divided into a video signal interval T _a and the audio signal interval T _b, a video signal obtained by continuously during video recording to the video signal interval T _a, respectively audio signals to the audio signal section T _b Record. When recording a still image, a video signal for one screen is set to 228 in the audio signal section T _b .
Record over track T.

FIG. 1 shows a circuit block diagram of a main part of a video camera. In FIG. 1, the image pickup signal from the solid-state image pickup device is A after being subjected to output processing such as sample hold.
It is supplied to the / D converter 2 and converted into a digital image pickup signal here. This digital image pickup signal is supplied to the camera process circuit 3, and the camera process circuit 3 extracts a luminance component (Y) and a color difference component (RY, BY) from the image pickup signal.

The video signals of the luminance component (Y) and the color difference components (RY, BY) output by the camera process circuit 3 are D /
After being converted into an analog signal by the A converter 4, it is supplied to the video process circuit 5. The video process circuit 5 converts the video signal into a video signal for recording, and the video signal is RF-converted.
It is supplied to the magnetic head 7 via the circuit 6. Magnetic head 7
Thus, the video signal is recorded in the video signal section T _a of the tape 1, and the video signal of one field is recorded per one track T.

The video signals of the luminance component (Y) and the color difference components (RY, BY) output by the camera process circuit 3 are supplied to the arithmetic circuit 8, and the output of the arithmetic circuit 8 is the first changeover switch. It is led to the a fixed contact of SW ₁ . The first changeover switch SW ₁ is configured to be able to selectively switch between the a fixed contact and the b fixed contact, and the still image processing circuit 1 is provided at the b fixed contact.
The video signal expanded by 2 is guided. The movable contact of the first changeover switch SW ₁ is connected to the input port of the frame memory 9.

The frame memory 9 is configured to be able to store a video signal for one frame, and the reading and writing of the frame memory 9 are controlled by the control circuit 10.
Read and write can be done simultaneously and independently,
The output of the frame memory 9 is fed back to the arithmetic circuit 8. The arithmetic circuit 8 is configured so that the amount of feedback from the frame memory 9 can be varied, and this amount of feedback is controlled by the control circuit 10. The control circuit 10 executes control based on the data from the setting unit 11, and the setting unit 11 can set how many fields (M) and how many (N) video signals are to be taken in total.

The output of the frame memory 9 is also supplied to the still picture processing circuit 12, which divides the video signal into blocks, performs ADRC compression on a quarter, and adds a synchronizing signal and the like. Output. Still image processing circuit 12
Output is led to a fixed contact of the second changeover switch SW ₂ . The second changeover switch SW ₂ is configured to be able to selectively switch between the a fixed contact and the b fixed contact, and the movable contact of the second changeover switch SW ₂ is connected to the PCM processing circuit 13. The PCM processing circuit 13 converts the video signal or the audio signal into PCM, and the PCM signal is the RF circuit 6.
Is supplied to the magnetic head 7 via. Magnetic head 7
Is recorded in the audio signal section T _b of the tape 1.

A circuit block diagram of the arithmetic circuit 8 is shown in FIG. In FIG. 2A, the arithmetic circuit 8 is composed of second and first multipliers 15 and 16 and an adder 17, and the input video signal is sent to the first multiplier 15 and the feedback signal is sent to the second multiplier 15.
It is input to each of the multipliers 16. First multiplier 15
And the outputs of the second multiplier 16 are added by the adder 17 and output. The respective coefficients of the first multiplier 15 and the second multiplier 16 are K and 1-K, and K is changed between 0 and 1. M
When it is set to obtain a total of N field images for each field, the control circuit sets K = 1 for each M field.
Coefficients are generated such as 1/2, 1/3, ..., 1 / N.

FIG. 2B shows a circuit block diagram of a modified example of the arithmetic circuit 8. In FIG. 2B, the arithmetic circuit 8 is composed of a multiplier 8 and first and second subtractors 19 and 20. The input video signal is the first and second subtractor 1
The feedback signals are input to the second subtractor 2 and the second subtractor 2 respectively.
It is entered as 0. The second subtractor 20 subtracts the feedback signal from the input video signal, and the subtracted signal is output to the multiplier 18. The multiplier 18 outputs the result of multiplication by the coefficient of 1-K to the first subtractor 19. The first subtractor 19 subtracts the output signal of the multiplier 18 from the input video signal and outputs it. Even with this configuration, the same calculation result as that of FIG. 2A can be obtained.

The operation of the above configuration will be described below. When the moving image recording mode is selected, the image pickup signal continuously output from the solid-state image pickup device is converted by the camera process circuit 3 into a video signal of a luminance component (Y) and a color difference component (RY, BY). , And is converted into a video signal for recording by the video process circuit 5. The converted video signal is supplied to the magnetic head 7 via the RF circuit 6 and the video signal section T _{a of the} tape 1 is supplied.
Continuously recorded in. The second changeover switch SW ₂ is connected to the b fixed contact side, and the audio signal is supplied to the PCM processing circuit 13 via the second changeover switch SW ₂ .
The audio signal converted into PCM by the PCM processing circuit 13 is R
It is supplied to the magnetic head 7 through the F circuit 6 and continuously recorded in the audio signal section T _b of the tape 1.

When the still image recording mode is selected during the moving image recording mode, both the first changeover switch SW ₁ and the second changeover switch SW ₂ are connected to the a fixed contact side. Then, the control circuit 10 outputs the coefficient 1 to the arithmetic circuit 8 for one frame period, and the video signal for one frame is supplied to the frame memory 9 through the arithmetic circuit 8 and the first changeover switch SW ₁ . 1 temporarily stored in the frame memory 9
The video signal for the frame is ¼ in the still image processing circuit 12.
And is supplied to the PCM processing circuit 13 via the second changeover switch SW ₂ . In this PCM processing circuit 13, P
The commercialized video signal is supplied to the magnetic head 7 via the RF circuit 6 and recorded in the audio signal section T _b of the tape 1. One frame of a video signal (still picture) is recorded using the voice signal section T _b of 228 tracks.

In the still image recording mode, the setting unit 1
If M = 2 and N = 4 are set in 1, the control circuit 1
0 outputs a coefficient as shown in FIG. 3 to the arithmetic circuit 8, and a video signal for one field is taken in four times at a rate of once every two fields. As shown in FIG. 3, since the feedback rate is zero in the section of the coefficient 1, the video signal of the P ₁ field is taken into the frame memory 9, and the feedback rate is 1/2 in the section of the coefficient 1/2. The frame memory 9 takes in a video signal in which the P ₁ field and the P ₃ field are uniformly mixed. Further, since the feedback ratio is 2/3 in the section of the coefficient ⅓, the video signal in which the P ₁ field, the P ₃ field and the P ₅ field are uniformly mixed is taken into the frame memory 9, and the coefficient ¼ Since the feedback ratio is 3/4 in the section of, the frame memory 9 has P ₁ field, P ₃ field,
A video signal in which the P ₅ field and the P ₇ field are uniformly mixed is captured. In this way, the frame memory 9
The video signal captured by the still image processing circuit 1 is the same as above.
2, second changeover switch SW ₂ , PCM processing circuit 13, R
The F circuit 6 and the magnetic head 7 are guided in this order and recorded in the audio signal section T _b of the tape 1. Therefore, a moving image and a multiple-exposure still image are recorded at the same time.

When the still image reproduction mode is selected, the first changeover switch SW ₁ is a fixed b contact and the second changeover switch SW _{2 is}
Are respectively connected to the fixed contacts a. The video signal in the audio signal section T _b picked up by the magnetic head 7 is supplied to the PCM processing circuit 13 via the RF circuit 6, where P
The CM signal is decoded and output to the still image processing circuit 13. The still image processing circuit 13 expands the video signal four times,
The expanded video signal is supplied to the frame memory 9 via the first changeover switch SW ₁ . The video signal for one frame fetched in the frame memory 9 is repeatedly read, and the read video signal is output to a display device (not shown) to display a still image on the display device.

The still image of the multiple exposure is the still image P ₁ ,
Since the video signals of the P ₃ , P ₅ and P ₇ fields are uniformly mixed, a uniform exposure amount is projected.

In this embodiment, the multiple-exposure still image is obtained by signal-processing the video signal in the unit of one field. However, it may be constructed so as to be obtained by processing the image signal in the unit of one frame. good.

[0024]

As described above, according to the present invention, an arithmetic circuit to which an input video signal is guided and a memory for storing the output of this arithmetic circuit are provided, and the output signal of this memory is sent to the arithmetic circuit. By feeding back and controlling the amount of this feedback, the video signals mixed for several screens are taken into the memory, so that a multiple-exposure still image can be obtained separately from the moving image even during recording of the moving image. Has the effect.
Further, by increasing the amount of feedback to the arithmetic circuit stepwise under a certain law, it is possible to obtain a multiple exposure still image in which a plurality of still images have a uniform exposure amount.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a video camera (embodiment).

2A is a circuit block diagram of an arithmetic circuit, and FIG. 2B is a circuit block diagram of a modified example of the arithmetic circuit (embodiment).

FIG. 3 is a time chart diagram (example).

FIG. 4 is a diagram showing a recording format of a tape (example).

[Explanation of symbols]

 8 ... Arithmetic circuit 9 ... Frame memory (memory) 10 ... Control circuit

Claims (2)

[Claims] 1. A memory capable of storing a video signal for one screen is provided, the output of an arithmetic circuit is supplied to this memory, and an input video signal and a feedback signal from the memory are supplied to this arithmetic circuit, respectively. A control circuit capable of controlling writing and reading of the memory and a feedback amount to the arithmetic circuit is provided, and the input video signal is taken into the memory a plurality of times and the feedback amount from the memory is controlled. And a video camera. 2. When the control circuit fetches N video signals at a rate of once per M screens, the control circuit fetches video signals for one screen at M screen intervals into the memory. The control is performed so that K = 1, 1/2, 1/3, ..., 1 / N, where K is an input video signal amount to the arithmetic circuit and 1-K is a feedback amount. The video camera described in 1.