JPH06189193A - Video camera - Google Patents

Abstract

PURPOSE:To perform character insertion without color impurity and a fading processing by inexpensive constitution with the small number of parts. CONSTITUTION:An video camera is provided for adder 15 for blanking mixing control use for adding composite blanking signals and character masking signals, a luminance signal path and a chrominance signal path respectively. Further, two blanking mixing circuits 2 and 3 for setting luminance signals and chrominance signals in both a composite blanking period and a character masking period to a black level by the output signals of the adder 15 are provided and a mixer 16 for fader control use for mixing analog fader control signals with character white signals for character display use is provided in the rear state of both the blanking mixing circuits 2 and 3 respectively. Also, two variable gain amplifiers 4 and 5 for a fader use controlled by the output signals of the mixer 16 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera having a fade processing function and a character insertion function.

[0002]

2. Description of the Related Art Conventionally, in a portable video camera such as a home-use 8 mm video camera, a fade processing function for performing fade-in or fade-out on an image pickup output and a character such as date, time and title are inserted. Some have a character insertion function. An example of this type of conventional video camera having a fade processing function and a character insertion function is configured as shown in FIG. 6, and the image pickup output of the camera unit 1 shown in FIGS. The luminance signal Yi and the color signal Ci are supplied to the blanking mixing circuits 2 and 3, respectively.

Both mixing circuits 2 and 3 are provided with a composite blanking signal C.C. The BLK sets the portion of the composite blanking period A in which the luminance signal Yi and the chrominance signal Ci are subjected to blanking mixing and each synchronizing signal is added to the black level (pedestal level). The output signals of both mixing circuits 2 and 3 are the fader variable gain amplifiers 4 and
5, the amplifiers 4 and 5 are fed to the video tape recorder section (hereinafter referred to as the VTR section) 6, and the gain is 0 when the fade-in is performed by the analog fader control signal FD of the fader control signal generator 7. The gain gradually decreases from 1 to 0, and the gain gradually decreases from 1 to 0 at the time of fading out.

The luminance signal Y is controlled by this gain increase / decrease control.
i, the color signal Ci is subjected to a fade process, and the output signals of the amplifiers 4 and 5 subjected to this process are the sync signal adding circuit 8 and
It is supplied to the burst signal adding circuit 9. Then, the sync signal adding circuit 8 performs setup addition, white clipping, and sync signal addition processing on the luminance signal Yi to obtain the luminance signal Yi as a luminance signal Y '(camera luminance signal) shown in FIG. 7C, for example.
Then, the burst signal adding circuit 9 adds the burst signal to the color signal Ci to form a color signal C '(camera color signal) shown in FIG. 7 (j).

Incidentally, FIG. 7 (c) shows a waveform when the fade processing function is off. Further, the luminance signal Y'of the synchronizing signal adding circuit 8 is V because V is used for character insertion.
The sync chip clamper 10 of the TR section 6 applies the sync chip clamp to the analog switch circuit 11 having two inputs. Further, the character generator 12 of the VTR unit 6 responds to the character by displaying the character white signal CHR. W and the character masking signal CHR.
Generate BLK.

Then, the character white signal CHR. W is supplied to the adder 13 and supplied to the color synchronization signal C.C.
SYNC is added, and the output signal MIXa of the adder 13 shown in FIG. 3F is supplied to the analog switch circuit 11 via the sync chip clamper 14.

This analog switch circuit 11 uses the character masking signal CHR. This signal CHR. In the non-masking period when BLK becomes low level (hereinafter referred to as L), the luminance signal Y ′ of the sync chip clamper 10 is selected and output, and the character masking signal CHR. The output signal MIXa of the sync chip clamper 14 is selected and output in the character masking period B for character insertion in which BLK becomes high level (hereinafter referred to as H).

Therefore, the luminance signal Y ″ after character insertion output from the analog switch circuit 11 is shown in FIG.
As shown in (h), the character white signal CHR. W = H
When the character blanking signal CHR. BLK = H and character white signal CHR. When W = L, the black level for edging is set, and the character blanking signal CHR. When BLK = L, the original luminance signal Y ′ is obtained. Then, the luminance signal Y ″ of the analog switch circuit 11 and the color signal C ′ of the burst signal adding circuit 9 form a video signal of an image pickup output, and the monitor display and recording of this signal are performed.

[0009]

In the case of the conventional video camera of FIG. 6, two variable gain amplifiers 4 and 5 for performing fade processing, two sync chip clampers 10 and 14 for performing character processing, and an analog switch. The circuit 11 and the adder 13 are required, the number of parts is large, and there is a problem that the cost becomes high. Moreover, since the color signal C'is not subjected to character insertion processing, the subject color of the photographed image affects the character in the character blanking period B and its edging, causing so-called character turbidity and impairing the image quality.

In the conventional video camera of this type having the fade processing function and the character insertion function, the color signal C'is also subjected to character insertion processing to fix its level to prevent the above-mentioned character turbidity. There is also
In this case, the number of parts is larger than that in FIG. 6 and the cost is higher. An object of the present invention is to enable fading processing and character insertion without character turbidity with an inexpensive configuration having a small number of parts.

[0011]

In order to achieve the above object, in the video camera of the present invention, a blanking mixture control for adding a composite blanking signal and a character masking signal to perform fade processing and character processing. For each of the luminance signal path and the chrominance signal path for setting the luminance signal and the chrominance signal in the composite blanking period and the character masking period to the black level by the output signal of the blanking mixing control adder Blanking mixing circuit, a fader control mixer that mixes an analog fader control signal and a character white signal for character insertion, and the output of the fader control mixer that is provided after each of the blanking mixing circuits. And two variable gain amplifiers for faders whose gain is controlled by signals.

[0012]

In the video camera of the present invention configured as described above, the luminance signal and the chrominance signal are synchronized with each other by the blanking mixing of both blanking mixing circuits based on the output signal of the blanking mixing control adder. The composite blanking period to be inserted and the character masking period to insert the character are both set to the black level for cleaning, and unnecessary brightness and color of the character insertion part are removed in advance.

Further, by the signal amplification of the variable gain amplifiers for both faders based on the output signal of the fader control mixer, the brightness signal and the chrominance signal through both blanking mixing circuits are faded by the fader control signal. At the same time, the character insertion portion of the character masking period is fixed by the character white signal and the character insertion processing is performed. Therefore, the fade processing and the character insertion without color turbidity can be performed with a configuration having a smaller number of parts and a lower cost than the conventional video camera which performs the character insertion processing only on the luminance signal.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment will be described with reference to FIGS. In FIG. 1, the same reference numerals as those in FIG. 6 indicate the same or corresponding ones, except that the two sync chip clampers 10 and 14 and the analog switch circuit 1 in FIG.
1, the adder 13 is omitted, and a blanking mixing control adder 15 and a fader control mixer 16 are provided.

The adder 15 comprises a logic circuit of an inverter 15a and an AND gate 15b as shown in FIG. 2, and the mixer 16 has a transistor 16 as shown in FIG.
It is composed of a high level selection circuit of a, 16b and a resistor 16c. In addition, + B is a DC power supply terminal of + 5V, for example.

The luminance signal Yi and the color signal Ci of the image pickup output shown in FIGS. 4A and 4H are the same as in the case of FIG.
It is supplied to the blanking mixing circuits 2 and 3 provided on the luminance signal path and the color signal path of the camera unit 1, respectively. In addition, the composite blanking signal C. BLK is adder 1
5 is supplied to the AND gate 15b and the character masking signal CHR. BLK is the inverter 1 of the adder 15
It is inverted by 5a and supplied to the AND gate 15b.

Then, the composite blanking signal C. BLK
And character masking signal CHR. The output signal M of the adder 15 is obtained by AND gate processing with the inverted signal of BLK.
IX _1, as shown in FIG. 4 (d) to each IH (H is horizontal scanning period), composite blanking signal C. Compound blanking period A and character masking signal C based on BLK
HR. L during character masking period B based on BLK
become.

Further, the output signal MIX ₁ is supplied to the blanking mixing circuits 2 and 3, and H and L of this signal MIX ₁ are supplied.
Thus, the gains of both mixing circuits 2 and 3 are changed to 1 and 0, and the luminance signal Yi and the color signal Ci are subjected to blanking mixing.
Therefore, the luminance signal Ya and the color signal Ca output from the blanking mixing circuits 2 and 3 are both black in the composite blanking period A and the character masking period B as shown in FIGS. 4 (e) and 4 (i). It is set to the level and cleaned.

The luminance signal Ya and the color signal Ca are supplied to the fader variable gain amplifiers 4 and 5. Next,
Fader control signal FD of the fader control signal generator 7
And the character white signal CHR. W is mixed by the mixer 16.

At this time, the fader control signal FD is as shown in FIG.
As shown in (a), it gradually decreases from H to L at the time of fade-in and gradually increases from L to H at the time of fade-out.
It should be noted that T ₁ , T ₂ , T ₃ , T ₄ , and T ₅ in FIG. 5 indicate periods of recording standby _, fade-in _, normal recording, fade-out, and recording standby accompanying the mode transition of the video camera during recording.

Then, for example, the mixer 1 with fade-in
The output signal MIX ₂ of FIG. 6 is, as shown in FIG. 5B, which is an enlarged view of the periods τa and τb of FIG. The waveform is a composite of high levels of W. It should be noted that 1V in the figure indicates a field scanning period. The output signal MIX ₂ is supplied to the amplifiers 4 and 5 and the synchronizing signal adding circuit 8, and the gains of the amplifiers 4 and 5 are 1 (maximum) when the output signal MIX ₂ is L and 0 (minimum) when the output signal MIX ₂ is H. The output signal MIXb changes according to the output signal MIXb.

Further, the output signal of the amplifier 4 is supplied to the synchronizing signal adding circuit 8 and set up to 7.5% (minimum) when the output signal MIX ₂ is L and 100% (maximum) when it is H. After that, white clip and sync signal addition processing is performed. Therefore, the output signal of the synchronization signal adding circuit 8 is a signal obtained by increasing the output signal of the amplifier 4 by 7.5% when the output signal MIX ₂ is L, and the output signal of the amplifier 4 is 100% when the output signal MIX ₂ is H. The white level saturation signal is increased by%.

To simplify the explanation, consider a case where the fader control signal FD is fixed to L and the fade processing function is turned off, as in the periods T ₁ , T ₃ , and T ₅ in FIG. The output signal MIX ₂ is the character white signal CHR. It becomes H only when H of W, and L otherwise.
Since the sync signal adding circuit 8 holds the setup level of the character white signal CHR. In the border portion where W becomes L, 7.5%, and the character white signal CHR. The character portion in which W becomes H becomes 100%, and its output signal is, as shown in FIG. 4 (g), a white character with a black border is inserted, which is similar to the luminance signal Y ″ in FIG. 6 (h). It becomes the luminance signal Y ₀ .

When the fader control signal FD is changed and the fade processing function is turned on during the periods T ₂ and T ₄ in FIG. 5, the output signal MIX ₂ changes to the character white signal CH.
R. It becomes H when W is H, and changes in accordance with the fader control signal FD at other times, so the output signal of the sync signal adding circuit 8 becomes a signal in which the character is fixed to white and faded. . On the other hand, the output signal of the amplifier 5 is supplied to the burst signal adding circuit 9, which adds the burst signal to the output signal of the amplifier 5 to form the color signal C ₀ .

At this time, the output signal of the amplifier 5 is fixed to the black level in the character masking period B, and the character white signal CHR. Since the gain of the amplifier 5 becomes 0 when W is H, the color signal C ₀ is fixed at the black level during the character masking period B as shown in FIG. Then, the luminance signal Y ₀ and the color signal C ₀ are used for monitor display, video recording, etc. At this time, a white character with a black outline is displayed in the character masking period B without being influenced by the subject.

Therefore, a fade process and character insertion without color turbidity can be performed by an inexpensive structure having a smaller number of parts as compared with FIG. Of course, it can be applied to various video cameras having a fade processing function and a character insertion function.

[0027]

Since the present invention is configured as described above, it has the following effects. A composite blanking period in which a synchronizing signal of a luminance signal and a chrominance signal is inserted by blanking mixing of the blanking mixing circuits 2 and 3 for the luminance signal path and the chrominance signal path based on the output signal of the blanking mixing control adder 15 and Both the character masking period portion in which the character is inserted can be set to the black level for cleaning, and further, the fader variable gain amplifiers 4 for the luminance signal and the chrominance signal based on the output signal of the fader control mixer 16 are used. By the signal amplification of 5, it is possible to perform the fade processing by the fader control signal on both the blanking-mixed signals, and perform the character insertion processing by fixing the level of the character portion in the character masking period by the character white signal. Therefore, the fade processing and the character insertion without color turbidity can be performed by the inexpensive structure having a smaller number of parts than the conventional video camera which performs the character insertion processing only on the luminance signal.

[Brief description of drawings]

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

FIG. 2 is a detailed connection diagram of the blanking mixture control adder of FIG.

3 is a detailed connection diagram of the fader control mixer of FIG. 1. FIG.

4 (a) to (j) are waveform diagrams of respective parts for explaining the operation of FIG.

5A and 5B are fader control signals of FIG.
It is explanatory drawing of the output signal of the mixer for fader control.

FIG. 6 is a block diagram of a conventional example.

7A to 7J are waveform diagrams of respective parts for explaining the operation of FIG.

[Explanation of symbols]

 2,3 Blanking mixing circuit 4,5 Variable gain amplifier for fader 15 Blanking mixing control adder 16 Fader control mixer

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[Procedure amendment]

[Submission date] February 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Then, the character white signal CHR. W is supplied to the adder 13 to output the composite sync signal C.C. Adder 13 shown in (f) of FIG.
Output signal MIXa is supplied to the analog switch circuit 11 via the sync chip clamper 14.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

[Action] When the video camera of the invention constructed as described above, the blanking mixing of both blanking mixing circuit based on the output signal of the blanking mixing control adder, the luminance signal and the color signal double Gaube Both the ranking period and the part of the character masking period in which the character is inserted are set to a black level for cleaning, and unnecessary brightness and color of the character insertion part are removed in advance.

Claims (1)

[Claims] 1. A blanking mixing control adder for adding a composite blanking signal and a character masking signal, and a composite provided by an output signal of the blanking mixing control adder provided in each of a luminance signal path and a chrominance signal path. Two blanking mixing circuits that set the luminance signal and color signal in the blanking period and the character masking period to a black level, and a fader control mixer that mixes an analog fader control signal and a character white signal for character display. And a fader variable gain amplifier that is provided in each stage after the both blanking mixing circuits and whose gain is controlled by the output signal of the fader control mixer.