JPS60140990A - Video tape recorder incorporating camera - Google Patents

Abstract

PURPOSE:To allow prevention of signal deterioration due to simplification of a circuit and short of a signal path by constituting in such a way that a line sequential color different signal obtained from a video camera is synchronized before it is modulated by the prescribed carrier and a low band conversion is executed by utilizing directly a low band converting carrier after the synchronization. CONSTITUTION:A color different signal is directly balanced and modulated by a low band converting carrier, thereby becoming a low band converted signal. Namely, it is directly balanced and modulated not by a chrominance subcarrier of 3.58mHz but by a low band converting carrier in modulating circuits 22 and 23 connected to a coincidence circuit 11. As a result, the low band converting chrominance signal obtained in an adder 14 has a quality equal to that formed in a popular video tape recorder without camera; therefore a video tape recorder incorporating a camera 21 need not execute frequency separation, low band conversion, etc., which are necessary for recording on a magnetic tape after an NTSC system color television signal has been formed as in the conventional video tape recorder without camera.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a camera-integrated video recorder using a line-sequential imaging type solid-state imaging device.

Background Art A color video camera that uses a solid-state image sensor (COD) that has no afterimages or burn-in in place of the conventional image pickup tube has been proposed, and various improvements have been made to obtain more natural color reproduction and higher image quality. be. For this type of COD color video camera, the color separation method is the key to obtaining the required resolution, and various methods such as the phase separation method, frequency separation method, and step energy method, which are considered to be highly practical, are also available. The current situation is that each has its advantages and disadvantages. for example.

When the frequency separation method is combined with the frame accumulation mode, there are problems such as equivalent afterimages caused by interlacing and flicker near the vertical limit resolution, so a negative impact on image quality cannot be avoided. In this case, there was a problem in that the vertical resolution was inferior to that in the frame accumulation mode due to the fact that vertical correlation was not used.

In particular, when using a line-sequential imaging type solid-state image sensor in field accumulation mode, the signal charges of two pixels in the vertical direction are mixed, which limits the flexibility of the one-color multiplexing method. When using the mode and readout color filters for the second line, it is not possible to obtain the color signals necessary for color reproduction. Therefore, when performing single-chip colorization using the field accumulation mode, two pixels in the vertical direction Even if the signal charges of 2 are mixed, there is a problem in that a color filter configuration is required that provides equal luminance signals in each field and each line, and at least two types of color signals can be obtained in each horizontal line.

In an attempt to meet this issue, 9, for example, TV E7 Academic Journal Vol. J7, A, /θ(/Riri (7)
A color video camera using a 2-pixel mixed readout color filter is introduced in a paper titled "Single-chip color conversion method for 7-f-/'-domain storage mode COD." FIGS. 1A and 1B are a schematic circuit diagram showing an example of this type of conventional color video camera and a diagram showing an arrangement pattern of color filters of the conventional color video camera, respectively.

In the conventional color video camera shown in FIG.
This color filter λ has a repeating arrangement pattern of two columns and rows, as shown in FIG. In Figure 1 (13), 1M represents magenta, Oy represents cyan, and Ye represents yellow. In relation to the three primary colors of light, R (red), G (green), and IB (blue),
M=R1B, Cy=G+B.

Yθ=G0R. The arrangement pattern of the color filter λ is
If the 7th line is a repetition of M, G, M, G...

The 7th line is a repetition of Oy, Ye, Cy, Ye..., and the 3rd line is the opposite of the 7th line, with G,
M, G, M... are repeated, and the 4th line is the same as the 2nd line, p C7*Yθ, Oy, Ye...
will be repeated.

Here, the luminance signals of the n line and n+/line in the A field are YAn I, and the color signal of YAn+b is CAnt
OAn+/ # Luminance signals of n lines and n+/ lines in B field adjacent to A field as YBn
+YBn-1-/s Color signal CBn l CBn
+ /, then the signal output Sn of n line and n + /
Line signal output Sn+hama, respectively Sn=Yn+0nsinωct 8n+/=Yn+/+C'n+/8in (ω(,1
+π). However, ωC is the solid-state image sensor 3
This is the carrier wave angular frequency of the color signal determined by the readout cycle of the color signal.

Note that each luminance signal component Yn+Yn-1-/ and each color signal component On, On+/ are as follows.

Yn=(Ye+Mg)+(Oy×G)=,2
R-1-j G-4-2B Yn+/=(Ye 10Mg) + (Cy +')=
2R+JG+2B On=(Ye+Mg)-(Oy+G)=-R-G On+/mi(Oy+Mg)-(Y8+G)=2B-G, so between each field and each line.

The luminance signal components Yn and Yn+/ take equal values.

Since two types of color signals 011sinωat and an-4-7sin (ωct+π) are obtained from the horizontal line,
Therefore, the signal output Sn s Sn+/ has 9 electrical signal components an, On+/ has an angular frequency ω(3(: 3.JJ').
After performing band P liquid processing with a center frequency of ωC and a bandwidth of /MHz.

If synchronous detection of angular frequency ωC is performed, 9 color difference signals JR-G
, 2B-G can be obtained.

The color difference signals 2R-G and 2B-4 thus obtained are modulated with color subcarriers with phases corresponding to 2R-G, 2B-G on the nine color coordinate axes, thereby obtaining the color signals necessary for colorization. It will be done. The video processing process that follows the outlined colorization method will be briefly explained below with reference to FIG.

First, the light from the subject is filtered using a lens and an infrared cut filter! After passing through a one-color filter λ, etc., the image is formed on the solid-state image sensor 3. The solid-state image sensor 3 is driven by a drive circuit 3a connected to a synchronization signal generation circuit B using a crystal oscillator. Among the outputs of the solid-state image sensor 3, the wideband luminance signal Y (=, 2R+jG-)-, 2B) is passed through the low-band P-wave circuit 7, and the color difference signal 0 (=2R-G
, , 2B-G) are separated and extracted by passing through a band p-wave circuit l and a synchronous detection circuit.

The color difference signal C is the white balance circuit 1 for two-color temperature correction.
After passing through 0, /delay the signal for the horizontal scanning period/
Two types of color difference signals JR are generated by the synchronization circuit /I in which the /H switching circuit //b with a switching period of 7 horizontal scanning periods is connected to the parallel connection circuit of the H delay circuit //a and the signal line.
-G, 2B-G. These color difference signals 2R-G,
JB-G is a modulation circuit/2. /3 and balanced modulation with a predetermined color subcarrier.

After being added by the adder /It, the signals are supplied to the adder /A for brightness mixing in one color via the chroma-gamma correction circuit /J. This color/luminance mixing adder/A receives the broadband luminance signal separated and extracted by the low-frequency p-wave circuit 7.

By adding the composite synchronization signal, an NTSO television signal is obtained from the adder 16.

The white balance circuit io is supplied with a narrowband luminance signal for white balance that has passed through a low-frequency p-wave circuit lZA and a correction circuit 19 for blanking processing, which is separate from the wideband luminance signal.

By the way, the above-mentioned conventional color video camera is...

Since the configuration is connected to a separate video tape recorder via a connection cable, the color video camera/
It is assumed that the output is an NTSO television signal, and in order to perform processing according to the magnetic tape recording format within the video tape recorder, the single color signal is low frequency converted and the luminance signal is frequency modulated. There is a need. For this reason.

Regarding color signals, the modulation circuit in the color video camera/2. /J performs quadrature co-phase modulation using a single color subcarrier, and then performs modulation over 1.2 degrees in the video tape recorder by performing low frequency conversion using a low frequency conversion carrier.

This has the disadvantage that the signal processing path is complicated and the signal is more likely to deteriorate.

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned drawbacks, and uses a line-sequential color difference signal obtained from the video camera to integrate a color video camera and a video tape recorder using a line-sequential imaging type solid-state image sensor. of.

Synchronization is performed before modulation with the required carrier wave, and after synchronization, low-frequency conversion is performed directly using a carrier wave for low-frequency conversion. This makes it possible to simplify the circuit configuration and prevent signal deterioration by shortening the signal path. The purpose of the present invention is to provide a camera-integrated video tape recorder.

To achieve this object, the present invention provides a line-sequential imaging type solid-state image sensor, a separation means for separating a luminance signal and a color signal according to the frequency band of the output of the solid-state image sensor, and a separation means for separating a luminance signal and a color signal according to the frequency band of the output of the solid-state image sensor. a synchronous detection circuit that detects a color signal generated by the synchronous detection circuit in synchronization with a readout cycle of the solid-state image sensor; and a synchronization circuit that synchronizes a line-sequential color difference signal that is an output of the synchronous detection circuit.

The output of the synchronization circuit is modulated with a carrier wave for low frequency conversion.

The gist of this invention is to provide a modulation circuit for obtaining a low frequency converted color signal that can be directly recorded on a video tape recorder integrated with a video camera.

According to the present invention, when integrating a color video camera and a video tape recorder using a solid-state image sensor of a line-sequential imaging method, line-sequential color difference signals obtained from the solid-state image sensor can be converted to This is because the configuration is such that synchronization is performed before modulation with a carrier wave, and after synchronization, low-frequency conversion is performed directly using a carrier wave for low-frequency conversion.

The advantage of integrating a video camera and video tape recorder can be utilized.2 For example, after modulating the color difference signal with a color subcarrier specific to the NT-NEC system, the color difference signals can be synchronized using a C-type filter, etc. It is possible to eliminate the need for processes such as converting the color signal mixed with the luminance signal, or converting the color signal mixed with the luminance signal to low frequency, thereby simplifying the circuit configuration and preventing signal deterioration due to shortening of the signal path. It has some excellent effects.

DISCLOSURE OF THE INVENTION Two embodiments of the present invention will now be described with reference to FIG. 2 and the following figures. FIG. 2 is a schematic circuit diagram showing a main part of an embodiment of a camera-integrated video tape recorder according to the present invention.

In Fig. 2, the camera-integrated videotape recorder 2/ is
Since there is no need to create an NTSO color television signal, the two-color difference signal is directly used for low-frequency conversion. This is a configuration in which frequency multiplexing is performed on the luminance signal. Namely.

Unlike the conventional method, the modulation circuit 2 connected to the synchronization circuit/I
2. ．． In 2J, 3. Therefore, the low-frequency conversion color signal obtained by the adder/≠ can be directly balanced modulated not with the color subcarrier of The low frequency conversion color signal formed is of the same quality.

For this reason, the camera-integrated video tape recorder 21.

Unlike the conventional camera-separate type, there is no need to perform frequency separation, low frequency conversion, etc. necessary for recording on a magnetic tape after once forming an NT-NichiC color television signal.

Moreover, the camera-integrated videotape recorder 21 is.

Amplifier circuits 2'l, 23.2, etc. are placed everywhere.

The amplifier circuit Δ provided between the band E wave circuit ♂ and the synchronous detection circuit and the amplifier circuit U provided between the correction circuit /D and the white balance circuit 10 are arranged so that the gain can be varied for each horizontal scanning period. A pair of variable gain resistors RA* with different resistance values are connected via switches 23a and ua, which are respectively switched by the horizontal synchronizing signal of the synchronizing signal generation circuit.
RB, rA, and rB are connected.

Also, a synchronous detection circuit? and the white balance circuit 10, there is a low frequency p for suppressing the carrier wave used for synchronous detection.
The wave circuit 27 is connected. On the other hand, for wideband luminance signals, two gamma correction circuits are provided at the next stage of the low-frequency P wave circuit 70 to perform gamma correction.
Furthermore, a contour correction circuit 29 is provided at the next stage of the gun and ma correction circuit 2g.
a vertical edge correction circuit, which is operated by the output of the correction circuit 19 described above; 0 is contour correction circuit 2? This is a configuration for controlling.

In addition, in this embodiment, the color filters 2 having the arrangement pattern shown in FIG.
For example, the color filter 3 with the array pattern shown in FIG.
You may also use In FIG. 3, W// represents -R+G+B, and ye represents G+7R. In integrating a color video camera and a video tape recorder using a solid-state image sensor 3.

A line-sequential color difference signal obtained from the solid-state image sensor 3.

Synchronization is performed before modulation with a required carrier wave, and after synchronization, low frequency conversion is performed directly using a carrier wave for low frequency conversion, so the advantage of integrating a video camera and a video tape recorder can be utilized. For example, NT80
After modulating the color difference signal with a color subcarrier specific to the method, the color difference signal is synchronized using a comb filter, etc., or the color signal mixed with the luminance signal is separated and then low-frequency conversion is performed. This makes it possible to simplify the circuit configuration and prevent signal deterioration due to the shortening of the signal path.

[Brief explanation of drawings]

FIGS. 1A and 1B are a schematic circuit diagram showing an example of a conventional color video camera and an arrangement pattern of color filters of a conventional color video camera, respectively.
501 Figure 1 is a schematic circuit configuration diagram showing essential parts of an embodiment of the camera-integrated video tape recorder of the present invention;
The figure shows an arrangement pattern of a modified example of the color filter shown in FIG. 2. 32...color filter, 3...solid-state image sensor, ?
... band p-wave circuit, ri... synchronous detection circuit, /l.
...Synchronization circuit, 22. Phantom...modulation circuit. Patent applicant: NEC Home Electronics Co., Ltd.) - Hajime/Hiroshi -

Claims (1)

[Claims] A solid-state image sensor of a line-sequential imaging method, a separation means for separating the output of the solid-state image sensor into a luminance signal and a color signal according to a frequency band, and a readout of the color signal separated by the separation means from the solid-state image sensor. A synchronous detection circuit that detects signals in synchronization with the period, a synchronization circuit that synchronizes the line-sequential color difference signals output from the synchronous detection circuit, and a synchronization circuit that modulates the output of the synchronization circuit with a carrier wave for low-frequency conversion to generate a video signal. A camera-integrated video chip recorder is provided with a modulation circuit for obtaining a low-frequency converted color signal that can be directly recorded on the video chip recorder integrated with the camera.