JPH06351044A - Digital video camera device - Google Patents

Abstract

PURPOSE:To simplify the circuit configuration of a digital video camera device by which either one of the video signal from a digital video camera and the video signal from an external input terminal is selected and the signal is made to be recorded on a recording medium. CONSTITUTION:The circuitry which is necessary for selecting either one of the both of the video signal inputted from a digital video camera and the video signal inputted from an external input terminal and recording the signal on a recording medium 22 is simplified by transmitting the luminance signal transmitted from a solid-state image pickup element 2 and the luminance signal from the external input terminal, in an analog state and transmitting a color difference signal in a digital signal state, when the signal from the solid-state image pickup element 2 is transmitted to a digital signal recording device 21 and is recorded in the recording medium 22 after an A/D conversion is performed for the signal and the signal is processed in a digital area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video camera device, and more particularly, to a video camera device which converts an analog video signal obtained from an image pickup device into a digital video signal and digitally performs signal processing. It is suitable.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of a video camera device in which an analog signal output from a solid-state image pickup device is A / D converted and signal processing is performed in a digital domain. In FIG. 3, the video signal obtained through the lens element 1, the solid-state imaging device 2, the correlated double sampling circuit 3, and the gain adjusting circuit 4 is sampled by the A / D converter 5 to be a digital signal.

Then, the sampled digital signal is applied to the digital signal processing circuit 6. The digital signal processing circuit 6 generates a digital luminance signal and a digital color difference signal from the input digital signal. The digital luminance signal generated by the digital signal processing circuit 6 passes through the D / A converter 12 and the low-pass filter 13 and is converted into a band-limited analog luminance signal.

Further, the digital color difference signals pass through the D / A converters 35 and 36 and the low pass filters 37 and 38, and are converted into band-limited analog color difference color signals. And
Further, it is given to the modulator 39, converted into an analog color signal, and sent to the digital signal recording device 21 together with the analog luminance signal. The processing up to this point is performed at the sampling frequency of the image sensor.

On the other hand, the video signal input from the outside is Y
In the case of the C separated input, it is directly input to the switch circuits 8 and 9. In the case of the composite video signal Video, the luminance / color separation circuit 7 separates it into luminance / color signals, which are input to the switch circuits 8 and 9. Either the YC separated input or the composite video signal is selected by the switch circuits 8 and 9.

The analog luminance / color difference signals from the camera thus obtained and the analog luminance / color difference signals from the outside are selected by the switch circuits 14 and 15. And
The band of the analog luminance signal is limited by the low-pass filter 17, is given to the A / D converter 18, and is converted into the digital luminance signal by the A / D converter 18.

Further, the analog color signal is converted into an analog color difference signal by the demodulation device 40, and then A / D converters 41 and 4 are provided.
At 2, it is converted into a digital color difference signal. At that time, A / D
The sampling frequency of the conversion is adapted to be the sampling frequency of the digital VTR. The digital signal recording device 21 records the digital luminance / color difference signal converted as described above on the magnetic tape 22. As a result, the digital video signal is recorded.

At this time, the switch circuits 25 and 26 are switched to the REC side, and the analog luminance signal and the analog color signal are selected by the switch circuits 25 and 26 and output. The EVF 33 displays the brightness signal and the color signal output in this way, and is useful for monitoring during shooting.

During reproduction, the digital signal recording device 21
Generates a digital reproduction luminance / color difference signal from the signal reproduced from the magnetic tape 22. Of these signals,
The reproduced luminance signal is converted into an analog luminance signal by the D / A converter 23 operating at the sampling frequency of the digital VTR, and then the band is limited by the low pass filter 24 to become an analog reproduced luminance signal.

On the other hand, the digital color difference signal is digital V
D / A converter 2 operating at the sampling frequency of TR
It is converted into an analog color difference signal in 8 and 29, and thereafter, the band is limited in low pass filters 30 and 31 to become an analog reproduced color signal, which is further modulated in a modulator 32.

The switch circuits 25 and 26 are switched to the PB side at this time, whereby the modulated analog reproduction color signal is selected together with the analog reproduction luminance signal and output as a reproduction video signal.

[0012]

In the case of the conventional digital video camera device shown in FIG. 3, a digital luminance / color difference signal from the camera and an analog luminance / color difference signal from the outside are used.
In order to record and reproduce both the color difference signal,
A large number of A / D converters and D / A converters were required. Therefore, the circuit scale for constructing the digital video camera device becomes large, and it is difficult to reduce the cost.

In view of the above problems, the present invention selects a video signal from a digital video camera or a video signal from an external input terminal and records the selected signal on a recording medium. The purpose is to enable simplification of the configuration.

[0014]

A digital video camera device according to the present invention has a digital signal processing circuit and a digital signal recording device, converts an analog video signal obtained from an image pickup device into a digital video signal, and performs this conversion. The digital video signal is supplied from the digital signal processing circuit to the digital signal processing circuit, and the digital signal recording apparatus performs predetermined signal processing to record on a recording medium. Among the signals sent to the signal recording device, the luminance signal is sent in the state of an analog signal and the color signal is sent in the state of a digital signal.

Another feature of the present invention is that
The color signal is sent as a digital signal sampled at the frequency of the clock of the image sensor.

Another feature of the present invention is that the luminance signal input from the outside is sent as an analog signal and the chrominance signal input from the outside is sent as a digital signal sampled at a frequency four times as high as the subcarrier. I am trying.

[0017]

According to the present invention, after the signal from the solid-state image pickup device is A / D converted and processed in the digital area, the luminance signal and the external signal sent from the solid-state image pickup device when connecting to the existing digital recording device. The input luminance signal is sent in an analog state, and the color difference signal sent to the digital signal recording device is a digital color difference signal of the sampling frequency of the solid-state image pickup device, and the external input color signal is sampled at a frequency four times that of the subcarrier. Then, by converting and transmitting the digital color difference signal, it is possible to select either the video signal input from the digital video camera or the video signal input from the external input terminal and record it on the recording medium. The configuration of the circuit required to achieve this is simplified.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital video camera device of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a video camera showing a first embodiment of the present invention. As shown in FIG. 1, the video signal obtained through the lens element 1, the solid-state imaging device 2, the correlated double sampling circuit 3, and the gain adjusting circuit 4 is clocked by the A / D converter 5 in the clock of the solid-state imaging device 2. Sampled at frequency (MCLK),
Converted to digital signal.

The digital signal processing circuit 6 generates a digital luminance signal and a digital color difference signal. The digital luminance signal and the digital color difference signal are then supplied to the switch circuit 14 as a band-limited analog luminance signal after passing through the D / A converter 12 and the low pass filter 13. Further, the digital color signal is applied to the switch circuits 15 and 16, respectively.

On the other hand, the video signal input from the outside is Y
In the case of C separation input, it is input to the switch circuits 8 and 9 as it is, and in the case of a composite video signal, it is input to the switch circuits 8 and 9 after being separated into the brightness / color signals by the brightness / color separation circuit 7. These switch circuits 8 and 9 are
Are provided for selecting the luminance signal Y, and the switch circuit 9 is provided for selecting the color signal C.

The color signal selected by the switch circuit 9 is given to the A / D converter 10. Then, it is converted into a digital signal by the A / D converter 10 at a frequency four times as high as that of the sub-carrier, and then supplied to the demodulating device 11, where the demodulating device 1
1 is converted into a digital color difference signal.

The analog luminance signal and the digital color difference signal from the camera and the analog luminance signal and the digital color difference signal input from the outside, which are obtained in this way, are selected by the switch circuits 14 to 16, respectively. Then, the band of the analog luminance signal is limited by the low pass filter 17, and then the analog luminance signal is given to the A / D converter 18, where it is converted into a digital luminance signal. At this time, the sampling frequency is the sampling frequency of the digital VTR.

The digital color difference signal is converted by the sampling frequency conversion circuits 19 and 20 from the clock frequency (MCLK) of the solid-state image pickup device 2 or the frequency four times as high as the subcarrier to the sampling frequency of the digital VTR.

The digital luminance / color difference signal thus converted is applied to the digital signal recording device 21,
It is recorded on the magnetic tape 22 by the operation of the digital signal recording device 21. That is, the digital video is recorded by this.

At this time, the switch circuits 25 to 27 are RE
It is switched to the C side, and the analog luminance signal is output as it is. Also, the digital color difference signal is a D / A converter 2 which operates at the sampling frequency of the digital VTR.
After being converted into an analog color signal in 8 and 29, the modulator 32
It is output after being converted into a color signal modulated by. EV
F33 displays the output luminance signal and color signal,
It is used for monitoring during shooting.

Further, during reproduction, the reproduced signal is received from the digital signal recording device 21 magnetic tape 22 and
Generate a digital reproduction luminance / color difference signal. Of these reproduced signals, the reproduced luminance signal becomes an analog luminance signal in the D / A converter 23 which operates at the sampling frequency of the digital VTR, and thereafter, the band is limited by the low pass filter 24 to become the analog reproduced luminance signal. Become.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, components that operate in the same manner as in FIG. 1 are given the same numbers. The video signal obtained through the lens element 1, the solid-state imaging device 2, the correlated double sampling circuit 3, and the gain adjusting circuit 4 is sampled by the A / D converter 5 at the clock frequency (MCLK) of the solid-state imaging device 2 and digitally Become a signal.

The digital signal processing circuit 6 generates a digital luminance signal and a digital color difference signal. After that, the digital luminance signal passes through the D / A converter 12 and the low-pass filter 13 and is sent as a band-limited analog luminance signal to the digital signal recording device 21 together with the digital color difference signal.

On the other hand, the video signal input from the outside is YC
In the case of separate inputs, they are directly input to the switch circuits 8 and 9. In the case of the composite video signal Video, the brightness /
After being separated into luminance / color signals by the color separation circuit 7, they are input to the switch circuits 8 and 9. Then, one of these video signals is selected by the switch circuits 8 and 9 and sent to the circuit in the subsequent stage.

After that, the color signal is converted into a digital signal by the A / D converter 10 at a frequency four times as high as the subcarrier, and converted into a digital color difference signal by the demodulator 11.
The analog luminance signal and the digital color difference signal from the camera and the analog luminance and the digital color difference signal from the outside, which are obtained in this manner, are switched by the switch circuits 14 to
16 and is selected here and sent to the circuit in the subsequent stage.

The analog luminance signal is band-limited by the low-pass filter 17, and then converted into a digital luminance signal by the A / D converter 18. At this time, the sampling frequency is the sampling frequency of the digital VTR.

Further, the digital color difference signal is supplied to the solid-state image pickup device 2 by the sampling frequency conversion circuits 19b and 20b.
Clock frequency (MCLK) or 4 of subcarrier
The doubled frequency is converted into the sampling frequency of the digital VTR.

At this time, the switch circuit 34 selects whether the connected one is a digital camera or an external input, and the sampling frequency conversion circuit 19b,
20b changes the coefficient so as to convert from MCLK to the sampling frequency of the digital VTR or from four times the frequency of the subcarrier to the sampling frequency of the digital VTR.

Thus, even if MCLK is not equal to the frequency four times as large as the subcarrier (for example, in the case of NTSC using a solid-state image sensor with 250,000 pixels), frequency conversion should be performed appropriately. You can

The digital signal recording device 21 records the thus converted digital luminance / color difference signal on the magnetic tape 22. As a result, digital video recording is performed. Further, the switch circuits 25 to 27 are switched to the REC side at this time, and the analog luminance signal is output as it is.

The digital color difference signal is digital V
D / A converter 2 operating at the sampling frequency of TR
After being converted into an analog color signal in 8 and 29, the band is limited in low pass filters 30 and 31, and then the modulator 3
The color signal modulated by 2 is output. EVF33
Is displayed by the output luminance signal and color signal, and is used for monitoring during shooting.

Further, during reproduction, the reproduced signal is received from the digital signal recording device 21 magnetic tape 22 and
Generate a digital reproduction luminance / color difference signal. Of these reproduced signals, the reproduced luminance signal becomes an analog luminance signal in the D / A converter 23 which operates at the sampling frequency of the digital VTR, and thereafter, the band is limited by the low pass filter 24 to become the analog reproduced luminance signal. Become.

At this time, the switch circuits 25 to 27 are switched to the PB side, the analog luminance signal is unchanged, and the digital color difference signal is converted into the analog color difference signal by the D / A converters 28 and 29 operating at the sampling frequency of the digital VTR. , Becomes a color signal modulated by the modulator 32, and is output as a reproduced video signal together with a luminance signal.

[0039]

As described above, according to the present invention, a video signal after A / D conversion of a signal output from a solid-state image sensor and processing in a digital area and a video signal input from an external input terminal are When sending to a digital recording device for recording on a recording medium, the luminance signal sent to the digital signal recording device and the external input luminance signal are sent in the state of analog signals, and the color signals are sent in the state of digital signals. Therefore, it is possible to simplify the circuit configuration of the digital video camera device that can select and record on the recording medium either the video signal from the digital video camera or the video signal from the external input terminal. ,
The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital video camera device showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a digital video camera device showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing an example of a conventional digital video camera device.

[Explanation of symbols]

 1 lens element 2 solid-state image sensor 3 correlated double sampling circuit 4 gain adjustment circuit 5 A / D converter 6 digital signal processing circuit 7 luminance color signal separation circuit 8 switch circuit 9 switch circuit 10 A / D converter 11 demodulator 12 D / A converter 13 Low pass filter 14 Switch circuit 15 Switch circuit 16 Switch circuit 17 Low pass filter 18 A / D converter 19 Sampling frequency converter 19b Sampling frequency converter 20 Sampling frequency converter 20b Sampling frequency converter 21 Digital Signal Recording Device 22 Magnetic Tape 23 D / A Converter 24 Low Pass Filter 25 Switch Circuit 26 Switch Circuit 27 Switch Circuit 28 D / A Converter 29 D / A Converter 30 Low Pass Filter 31 Low Pass Filter 31 32 modulator 3 electronic viewfinder 34 switch circuits

Claims (3)

[Claims] 1. A digital signal processing circuit and a digital signal recording device, wherein an analog video signal obtained from an image pickup device is converted into a digital video signal, and the converted digital video signal is supplied to the digital signal processing circuit. In a digital video camera device adapted to perform a predetermined signal processing by the digital signal recording device and record it on a recording medium, among the signals sent from the digital signal processing circuit to the digital signal recording device, a luminance signal is an analog signal. A digital video camera device characterized in that color signals are sent in the form of signals and color signals are sent in the form of digital signals. 2. The digital video camera device according to claim 1, wherein the color signal is sent as a digital signal sampled at a frequency of a clock of an image pickup device. 3. The digital video camera device, wherein the luminance signal input from the outside is sent as an analog signal and the chrominance signal input from the outside is sent as a digital signal sampled at a frequency four times as high as the subcarrier. The digital video camera device according to claim 1, wherein