JP3291438B2 - VTR - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a VT R, in particular for example in consumer VTR or the like having a S terminal, blanking Rubakku signal for outputting a color signal of a blue back signal or the like during the setting of the signal no input or when the system V with processing circuit
Regarding TR .

[0002]

2. Description of the Related Art In a conventional blue-back signal processing circuit of this type, when a circuit (or IC) that outputs a blue-back signal can output only a composite signal,
A simple filter or the like for Y / C separation of a blue-back signal, which is a composite signal, is provided at an output stage, and after performing Y / C separation by the simple filter, an S terminal is output.

More specifically, referring to FIG. 3, a composite signal input from a video input terminal is supplied to a Y / C separation circuit 3 via a switch 1a and a luminance signal processing circuit 2, where the composite signal is converted. Y / C separation is performed. A luminance signal for recording and a chroma signal for recording are generated in the luminance signal processing circuit 2 and the chroma signal processing circuit 4, respectively, for the luminance (Y) signal and the chroma (C) signal which have been Y / C separated. Also, the luminance signal processing circuit 2
The chroma signal processing circuit 4 outputs a luminance signal, a chroma signal, and a composite signal as through signals. If the input is from the S terminal, for example, the luminance signal processing circuit 2 generates a composite signal from the luminance and chroma signals.

When a composite signal is supplied to the OSD circuit 5, the OSD circuit 5 outputs a character signal of character information and a blank signal in synchronization with the composite signal. By supplying the character signal and the blank signal of the character information to the superimposing circuits 6a and 6b, the luminance signal processing circuit 2 and the chroma signal processing circuit 4
The character information is superimposed on the luminance and chroma signals output as through signals from.

When the blue-back mode is designated, a blue-back signal is output from the OSD circuit 5, and the blue-back signal is transmitted to the LPF 7 and the BPF 8
After Y / C separation by the simple filter described above, the signal is output to the S terminal via the switches 1c and 1d. In the prior art shown in FIG. 4, an OSD IC (integrated circuit) 9 for inputting a luminance signal, a chroma signal, and a composite signal, which are through signals, is provided.
In IC9, superimposition of characters and Y /
C separation was performed.

[0006]

In the prior art shown in FIG. 3, filters (LPF7 and BPF8) and switches (1c and 1d) are required at the output stage, so that the cost is increased and the luminance is reduced by a simple filter. The high frequency component of the signal is missing, and the outline of the character becomes dull or the character becomes difficult to see due to blurring or the like.

On the other hand, the prior art shown in FIG. 4 has a problem that there are few types of ICs satisfying required performance, it is difficult to obtain desired specifications, and the cost is high. Another object of the present invention can improve the character of the sharpness at the blue back signal output by a simple circuit construction, to provide a VT R.

[0008]

According to the present invention, a recording mode is provided.
Receives the composite signal and converts it into a luminance signal and a chroma signal.
In a VTR equipped with a Y / C separation circuit for separation,
A first output means for outputting a back signal;
Blue back signal in recording mode in
Display output by giving to the used Y / C separation circuit
-Back luminance signal and blue-back
VTR characterized in that a VTR signal is generated.
It is.

[0009]

When the blue-back mode is designated, a blue-back signal is output from the first output means. The blue-back signal, which is a composite signal, is supplied to a Y / C separation circuit via a switching unit, where it is separated into a luminance signal and a chroma signal. Then, the luminance signal and the chroma signal are output to the S terminal via the superimposing means. In the blue-back mode, even if the character information signal is output from the second output means, the superimposing means does not superimpose the character information signal. The blue-back luminance signal and the blue-back chroma signal that have been subjected to the C separation are output.

[0010]

According to the present invention, when the Y / C separation circuit for the input video signal is not used in the main circuit block of the system, that is, in the blue-back mode, the Y / C separation circuit is provided. In the above, the blue-back signal is Y / C-separated, so that a signal separation filter such as an LPF or a BPF for the blue-back signal is not required, so that the cost can be reduced and the luminance signal component can be prevented from being lost.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0012]

Referring to FIG. 1, a blue-back signal processing circuit 10 of this embodiment has, for example, an S-VH
S video tape recorder built-in
Including input terminals 12a and 12b, in this embodiment,
A luminance (Y) signal is input from the S input terminal 12a, and a chroma (C) signal is input from the other S input terminal 12b. The luminance signal input from the S input terminal 12a is supplied to the changeover switch 14a, and the input to the luminance signal processing circuit 18 is selected together with the composite signal from the video input terminal 16.

When the composite signal from the video input terminal 16 is selected by the changeover switch 14a, the composite signal is sent to the Y /
It is provided to the C separation circuit 20. The composite signal supplied to the Y / C separation circuit 20 is separated there into a luminance signal and a chroma signal, and the luminance signal is again supplied to the luminance signal processing circuit 18 and subjected to emphasis and then FM modulation. And the like. And Y
/ C separation circuit 20 outputs the chroma signal
4b, is supplied to the chroma signal processing circuit 22.
Predetermined signal processing such as frequency conversion is performed.

On the other hand, when the input is from the S terminal, that is, by the changeover switches 14a and 14b,
When the input signals from the S input terminals 12a and 12b are selected, the above-described predetermined processing is performed on the luminance signal in the luminance signal processing circuit 18 and on the chroma signal in the chroma signal processing circuit 22. Then, both signals subjected to the signal processing are supplied to a magnetic head (not shown) and recorded on a recording medium (not shown) as a luminance signal for recording and a chroma signal for recording.

The luminance signal processing circuit 18 and the chroma signal processing circuit 22 further output a through signal which has not been subjected to the above-described processing to the input signal. In this embodiment,
A through composite signal is output from the luminance signal processing circuit 18 to the OSD-IC 24, and a through luminance signal is output to the superimposition circuit 26b.
2 outputs a through chroma signal to the superimposing circuit 26a. When the input is from the S terminal, the through-composite signal generated from the luminance signal and the chroma signal in the luminance signal
-Output to IC24.

When the composite signal is supplied to the OSD-IC 24, the OSD-IC 24 outputs a character and a blank signal of character information synchronized with the composite signal. That is, the OSD-IC 24
Includes a sync separation circuit (not shown) in which vertical and horizontal sync signals are generated based on the composite signal from the luminance signal processing circuit 18. As a result, character information to be superimposed is positioned.
Then, the character and blank signal are transmitted to the superposition circuit 2
6a and 26b, where they are superimposed on the luminance signal and the chroma signal output from the luminance signal processing circuit 18 and the chroma signal processing circuit 22 as through signals.

The OSD-IC 24 further includes a superimposing circuit (not shown). In the superimposing circuit, a character string is output from the composite signal to be output based on the vertical and horizontal synchronizing signals generated by the synchronizing / separating circuit. Information is superimposed. As a reference (synchronization) signal for determining a character position, for example, a servo circuit (not shown)
The vertical and horizontal synchronizing signals generated in the above can also be used.

The OSD-IC 24 outputs a blue-back signal when the blue-back mode is designated, so that the OSD-IC 24 constitutes a first output means. In other words, the OSD-IC 24 has a clock generating means (not shown) for generating a reference clock, and the microcomputer (control means) (not shown) uses a clock generating means (not shown) regardless of the presence or absence of an input signal (a composite signal in this embodiment). A blue-back signal is generated and output according to the reference clock.
As the OSD-IC 24, for example, LC74781 manufactured by Sanyo Electric Co., Ltd. is used.
The method of generating the blue-back signal in the IC 24 is well known and insignificant, so that the detailed description thereof will be omitted.

The superimposing circuits 26a and 26b do not operate when the blue-back mode is designated, even if the character and blank signal of character information are output from the OSD-IC 24. That is, OSD-I
The character and blank signal of the character information output from C24 are applied to, for example, a gate circuit (not shown) and input to superimposing circuits 26a and 26b according to a gate pulse from a microcomputer (not shown) or a gate pulse created separately. Is controlled.

In operation, when a recording mode is designated and a composite signal is input from the video input terminal 16, the composite signal is sent to the Y / C separation circuit 20 via the changeover switch 14a and the luminance signal processing circuit 18.
Given to. After the Y / C separation circuit 20 separates the composite signal into a luminance signal and a chroma signal, the luminance signal is subjected to predetermined signal processing in a luminance signal processing circuit 18 and the chroma signal is subjected to predetermined signal processing in a chroma signal processing circuit 22. Are recorded on a recording medium by a magnetic head (not shown).

The luminance signal and the chroma signal separated by the Y / C separation circuit 20 are used as through signals.
The signals are supplied to the superimposing circuits 26a and 26b, respectively.
A composite signal obtained by passing through the composite signal input from 6 is output to the OSD-IC 24.
As described above, the OSD-IC 24 generates a vertical and horizontal synchronizing signal from the composite signal from the luminance signal processing circuit 18, and outputs a character and a blank signal of character information based on the synchronizing signal. The character and blank signals are provided to superimposing circuits 26a and 26b, superimposed on the through luminance signal and the through-chroma signal, and then output from S output terminals 32a and 32b. The composite signal output from the OSD-IC 24 is provided to the video output terminal 34.

On the other hand, when the blue-back mode is designated, a blue-back signal is output from the OSD-IC 24, and this blue-back signal is output to the video output terminal 3.
4 and to a Y / C separation circuit 20 via a changeover switch 14a and a luminance signal processing circuit 18. In the Y / C separation circuit 20, the blue-back signal, which is a composite signal, is subjected to Y / C separation, and the luminance signal passes through the luminance signal processing circuit 18 and passes through the superposition circuit 26b.
The chroma signal passes through the changeover switch 14b and the chroma signal processing circuit 22 and is supplied to the superimposing circuit 26a. As described above, since the superimposition circuits 26a and 26b stop operating when the blue-back mode is designated, the Y / C-separated blue-back luminance signal and the blue-back luminance signal are output from the S output terminals 32a and 32b. A blue back chroma signal will be output.

When the recording mode is designated and the input is made by the S terminal, the S input terminal 12a
Is supplied to the luminance signal processing circuit 18 via the changeover switch 14a, and is subjected to a process for generating a recording luminance signal as in the case where the above-described composite signal is input. . The same applies to the chroma signal input from the S input terminal 12b. The input chroma signal is supplied to the chroma signal processing circuit 22 via the changeover switch 14b, and is subjected to processing such as frequency conversion.

The luminance signal and the chroma signal input to the S terminal are converted into through signals as superimposition circuits 26a and 26b.
And a luminance signal processing circuit 18
Thus, a composite signal generated from the luminance signal and the chroma signal is output to the OSD-IC 24.
As a result, the OSD-IC 24 outputs a character and a blank signal of character information synchronized with the composite signal. The character and blank signals are supplied to the superimposing circuits 26a and 26b, superimposed on the through luminance signal and the through-chroma signal, and then output from the S output terminals 32a and 32b.

When the blue-back mode is designated, a blue-back signal is output from the OSD-IC 24, and the blue-back signal is separated into a Y / C signal via the changeover switch 14a and the luminance signal processing circuit 18. Circuit 2
0 and Y / C separated. The luminance signal is output from the S output terminal 32a as a blue-back luminance signal via the luminance signal processing circuit 18 and the superimposing circuit 26b, and the chroma signal is transmitted to the changeover switch 14b, the chroma signal processing circuit 22, and the superimposing circuit 26a. Through the S output terminal 32b, the signal is output as a blue back chroma signal.

As described above, in a system in which the recording mode and the blue-back mode are not compatible at the same time, when the blue-back mode is set, the Y / C separation circuit which does not operate the blue-back signal which is a composite signal at that time. Since the signal separation is performed at step 20, it is not necessary to provide a filter for signal separation at the output stage as in the prior art shown in FIG. 3, so that the cost can be reduced and the Y level can be reduced without lowering the image quality. / C separation can be performed.

In a VTR which can be set on a blue-back screen while recording, a blue-back display and a blue-back display are set only when there is no signal input, and when there is an input signal, superimposed characters such as superimpose are superimposed. This can be realized by using a mode. FIG. 2 shows a blue-back signal processing circuit 10 according to another embodiment.
0 is provided before the luminance signal processing circuit 18;
The composite signal input from the video input terminal 16 is supplied to the Y / C separation circuit 20 via the changeover switch 14a.
Given to. The Y / C separated luminance signal and chroma signal are supplied to superimposing circuits 26a to 26d, and a character information signal is superimposed on the luminance signal and the chroma signal.
Whether or not to superimpose the character information signal in the superimposing circuits 26a to 26d is controlled by the control circuit 30. For example, when the luminance and chroma signals in which the character information is superimposed are recorded on a recording medium, the control circuit 30 , Superimposing circuits 26c and 26d are activated.

The luminance signal output from the superimposing circuit 26c is supplied to the luminance signal processing circuit 18 and the luminance signal shown in FIG.
Is supplied to the OSD-IC 24 as a signal for synchronization, as in the above-described embodiment. Then, in the blue-back mode, the blue-back signal output from the OSD-IC 24 is separated into a luminance signal and a chroma signal by the Y / C separation circuit 20, and the S output terminal 32a via the superimposing circuits 26a and 26b. And 32b, as well as being provided to the adder 28, so that a composite signal is output from the video output terminal 34.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional technique.

FIG. 4 is a block diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Blue back signal processing circuit 12a, 12b ... S input terminal 14a, 14b, 14c ... Changeover switch 16 ... Video input terminal 18 ... Luminance signal processing circuit 20 ... Y / C separation circuit 22 ... Chroma signal processing circuit 24 ... OSD- IC 26a, 26b ... superimposition circuit 32a, 32b ... S output terminal 34 ... video output terminal

Claims (3)

(57) [Claims] 1. A luminaire which receives a composite signal in a recording mode.
Equipped with a Y / C separation circuit for separating into a degree signal and a chroma signal
A VTR that includes a first output unit that outputs a blue-back signal, and outputs the blue-back signal in a blue-back mode.
To the Y / C separation circuit used in the recording mode
The blue-back luminance signal for display output.
And blue-back chroma signal
A VTR characterized by the following . 2. A second output means for outputting the character information signal, Contact
Preliminary further comprising a superimposing means for superimposing the character information signal to the Brightness signal and the click Loma signal, the superimposing means the character information in the blueback mode
It does not overlap the broadcast signals, according to claim 1, wherein VT R. 3. The apparatus further comprises control means for executing an output control instruction of the blue-back signal, wherein the control means outputs a blue-back output instruction.
The first output means outputs the blue-back signal;
VT R of claim 1 or 2 wherein.