JPH04297197A - Display device of video camera - Google Patents

Abstract

PURPOSE:To combine and execute the title display and the blue-back in a video camera. CONSTITUTION:In a memory 8 for storing a luminance signal for a title display, it is stored in a state that the luminance signal exists in the whole period in accordance with a blue-back instruction from a microcomputer 10. Therefore, by reading out the data of said memory, a video signal of a single color can be obtained easily.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a display device for a video camera (camera-integrated VTR) for realizing a screen blueback, and in particular to inserting a title on the screen and bluebacking the screen. This invention relates to a display device for a video camera that can be used for both functions with one circuit.

0002

[Prior Art] Television receivers do not like the occurrence of noise on the screen when there is no signal, so-called "sand storm".
A so-called blueback is known in which the screen is switched to a single color (for example, blue) during such a period. Recently, this blue back function has been required for video camera viewfinders as well. Video cameras have conventionally been equipped with an LSI for an OSD (on screen display) that displays characters on the viewfinder screen for the purpose of displaying "REC in progress" or the time. Therefore, it is conceivable to perform blueback using the LSI. For example, horizontal and vertical synchronization signals are generated by a synchronization signal generator built into the LSI. Then, the frequency of the 4fsc (fsc is subcarrier frequency) signal used as the system clock of the LSI is divided,
Burst signal and blue signal (180 for burst signal
(inverted phase). Then, the synchronization signal, the burst signal and the blue signal are mixed at a predetermined ratio in a mixing circuit,
What is necessary is to generate a blue signal.

0003

However, the above method requires additional circuits (frequency dividing means and mixing circuit), and the structure of the synchronizing signal generator is complicated, which is not desirable. In particular, when displaying colors other than blue, it is necessary to provide a mixing circuit with a corresponding ratio and a circuit that generates a color signal of the hue of that color.

0004

[Means for Solving the Problems] The present invention has been made in view of the above points, and provides a luminance signal input terminal to which a luminance signal of a video signal to be displayed is applied, and an analog signal from the luminance signal input terminal. A/D that converts luminance signals into digital signals
a conversion circuit, a memory that stores digital signals from the A/D conversion circuit in accordance with instructions from the microcomputer;
, G, B primary color signals; a brightness designation circuit that generates a brightness signal corresponding to the color designated by the microcomputer during the output signal generation period of the memory; and an output signal of the color designation circuit. a luminance signal matrix circuit for producing a luminance signal to be displayed in accordance with the output signal of the luminance specifying circuit; and an output luminance signal of the luminance signal matrix circuit. and a luminance signal switch that selectively switches and outputs the luminance signal from the luminance signal input terminal, a color signal input terminal to which a color signal of the video signal to be displayed is applied, and a color signal from the color signal generation means. a color signal switch that selectively switches and outputs the signal and the color signal from the color signal input terminal; and a switching means that switches to a state in which all the luminance signal information stored in the memory exists in accordance with a command from a microcomputer. It is characterized by comprising:

[0005]

According to the present invention, the memory for storing the luminance signal for title display is stored in a state in which the luminance signal exists for the entire period in response to a blueback command from the microcomputer. Therefore, a single color video signal can be easily obtained by reading data from the memory.

[0006]

[Embodiment] FIG. 1 is a circuit diagram showing an embodiment of the present invention (
1) is a clamp circuit that clamps the luminance signal from the luminance signal input terminal (2), (3) is a 1-bit A/D converter that converts the clamped luminance signal into a digital signal, (
4) is a PLL circuit that locks to the horizontal and vertical synchronizing signals from terminal (5), (6) is a timing signal generation circuit that generates various timing signals according to the output signal of PLL circuit (4), and (7) is a S-P conversion (serial-parallel mutual conversion) converts the digital signal applied serially from the A/D converter (3) to a parallel signal and stores it in the memory (8), and performs the inverse conversion when reading. ) circuit, (9) is an address counter for the S-P conversion circuit (7), and (10) generates commands for storing and displaying title signals, commands for blue screen display, etc. Microcomputer (microcomputer), (
11) is a command decoder that generates various control signals to execute instructions from the microcomputer (10), and (12) is an S
- When the output signal of the P conversion circuit (7) is generated, R,
Color specification circuit that selects and outputs three primary color signals of G and B, (13) is R-Y matrix circuit, (14) is B-Y
Matrix circuit, (15) is the color signal carrier wave (3.58
a first modulator that modulates the R-Y signal at (1 MHz);
6) is a carrier wave whose phase differs by 90 degrees from the carrier wave, and B-Y
a second modulator that modulates the signal; (17) is an adder; (17) is an adder;
18) is a luminance signal that selects and outputs YR, YG, and YB signals for luminance that match the color specified by the output control signal of the command decoder (11) when the output signal of the S-P conversion circuit (7) is generated. The designated circuit (19) is the signal YR, YG, YB
a luminance signal matrix circuit that generates a luminance signal according to the
(20) is applied with the luminance signal from the clamp circuit (1) and the luminance signal matrix circuit (19), and when the luminance signal matrix circuit (19) generates a luminance signal, selects the signal; otherwise, the clamp circuit (1) ) side, and the luminance signal switch (21) selects the signal when the output color signal of the adder (17) is generated, and otherwise selects the color signal input terminal (21).
2) is a color signal switch that selects a color signal from 2).

First, the case where the circuit shown in FIG. 1 is used to display a title will be explained. Title display refers to capturing a still image such as a title in advance with a video camera, storing it in the memory within the camera, and then reading out the contents of the memory on another desired screen and displaying it in an overlapping manner. It is. The user of the video camera captures an image for the desired title with the camera and presses the storage switch.

Then, in response to the switch, the microcomputer (10) and command decoder (11) operate, and the S-P
The conversion circuit (7) and address counter (9) are connected to the memory (8).
) is in the mode for writing to. The luminance signal of the title image is applied to the luminance signal input terminal (2), and its synchronization signal is sent from the terminal (5) to the PLL circuit (
4) is applied. The luminance signal clamped by the clamp circuit (1) is converted into a digital signal by the A/D converter (3), converted to a parallel signal by the S-P conversion circuit (7), and then converted to a parallel signal by the S-P conversion circuit (7). Stored in memory (8). The memory (8) has storage addresses corresponding to the entire area of the television screen.

Note that the title signal is taken in only for the luminance signal, and the color signal from the color signal input terminal (22) is not used. From this state, if the video camera user selects the background image on which he wants to display the title and presses the display switch, S
-P conversion circuit (7) and address counter (9) enter the mode for reading out the memory (8), and S-
The stored title signal is output as serial data from the P conversion circuit (7). At this time, the luminance signal in the video signal of the underlying screen on which the title is projected is sent to the luminance signal input terminal (2), and the color signal is sent to the color signal input terminal (2).
At 22), a synchronization signal is applied to terminal (5). Further, a control signal (color designation) for displaying a predetermined color, for example magenta color, is output from the command decoder (11) from the control terminals (23) and (24) to the color designation circuit (
12) and the brightness designation circuit (18). The color specifying circuit (12) generates R, G, and B signals necessary for magenta display while the signal is being applied from the S-P conversion circuit (7), and outputs the R-Y matrix circuit (13) and B signals. - applied to the Y matrix circuit (14). Then, the R-Y color difference signal is created in the R-Y matrix circuit (13), and the B-
A B-Y color difference signal is created in the Y matrix circuit (14), modulated by the carrier wave of the color signal in the first and second modulators (15) and (16), and further added in the adder (17). . As a result, the baseband color signal for title display is applied to the color signal switch (21), selectively switched with the color signal from the color signal input terminal (22), and output to the output terminal (25). .

On the other hand, the brightness designation circuit (18) generates R, G, and B signals for displaying the magenta color while the signal is being applied from the S-P conversion circuit (7), A brightness signal matrix circuit (19) converts the brightness signal into a brightness signal for displaying magenta, and applies the converted brightness signal to a brightness signal switch (20). As a result, the luminance signal for title display and the background luminance signal are selectively switched by the luminance signal switch (20) and output to the output terminal (26).

[0011] Therefore, by using the color signal and luminance signal of the output terminals (25) and (26), it is possible to display a desired title on the screen. Next, a case will be described in which the circuit shown in FIG. 1 performs blueback on the screen. The command in this case is
Generated from the microcomputer (10) and command decoder (11)
Each control signal is generated from That is, the S-P conversion circuit (7
) and the address counter (9) are in the write mode described above. Further, a signal is applied to the memory (8) so that all addresses are in a "signal present" state. For example, the reference power source (2
7) Switch the level to a high value. Then, memory (8
) signals will be stored at all addresses. When the storage in the memory (8) is completed, the command decoder (11) immediately controls the S-P conversion circuit (7) and the address counter (9) to switch to the read mode, and the S-P conversion circuit ( 7), a continuous "H" level signal is generated.

On the other hand, since the background color (for example, blue) is specified by the command decoder (11) to the color specifying circuit (12) and the brightness specifying circuit (18), R, G, and B corresponding to that color are specified. signal and YR, YG, YB signals are obtained. Therefore, regardless of the signal from the color signal input terminal (22), the color signal switch (21) outputs the blue color signal to the output terminal (22).
25). Furthermore, regardless of the signal from the luminance signal input terminal (2), the luminance signal switch (20) derives the luminance signal for blue to the output terminal (26).

Therefore, by using the color signal and luminance signal of the output terminals (25) and (26), it is possible to make the entire screen blue. In addition to switching the level of the reference power source (27), the level of the signal input terminal (- side) may be forcibly lowered, and various methods can be considered.

[0014]

As described above, according to the present invention, it is possible to provide a display device for a video camera that can perform both title display and blueback on the video camera. In particular, according to the present invention, even if the color of the blue background can be changed to various colors, no special circuit is required.
It is possible to provide a display device for a video camera that is multifunctional and has a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a display device for a video camera according to the present invention.

[Explanation of symbols]

(2) Brightness signal input terminal (3) A/D converter (8) Memory (10) Microcomputer (12) Color specification circuit (18) Brightness specification circuit (20) Brightness signal switch (21) Color signal switch (22) Color signal input terminal

Claims (2)

[Claims] 1. A luminance signal input terminal to which a luminance signal of a video signal to be displayed is applied, and an A/D that converts the analog luminance signal from the luminance signal input terminal into a digital signal.
a conversion circuit, a memory that stores digital signals from the A/D conversion circuit, a color designation circuit that generates R, G, and B primary color signals of predetermined colors during an output signal generation period of the memory, and the memory. a brightness designation circuit that generates a brightness signal corresponding to the predetermined color during an output signal generation period; a color signal creation means that creates a color signal to be displayed according to the output signal of the color designation circuit; A brightness signal matrix circuit that creates a brightness signal to be displayed according to an output signal of a designated circuit, and selectively switches and outputs the output brightness signal of the brightness signal matrix circuit and the brightness signal from the brightness signal input terminal. A luminance signal switch, a color signal input terminal to which a color signal of a video signal to be displayed is applied, and a color signal from the color signal generating means and a color signal from the color signal input terminal are selectively switched and output. a video signal on which a background signal is superimposed from the output signals of the color signal switch and the luminance signal switch; Or a display device for a video camera, characterized in that it obtains a single color video signal. 2. A display device for a video camera according to claim 1, wherein said switching means is means for changing a threshold value or an input terminal level of said A/D conversion circuit.