JPS5827B2 - Iroshingo Hatsuseisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that generates color signals for characters and symbols displayed on a color display device or the like.

Generally, when an image is displayed in color, the color subcarrier of 3.58 MHz is set to a phase corresponding to each color, as in NTSC color television broadcasting.

Television broadcast stations use automatic broadcast control devices that control broadcast signals according to predetermined broadcast programs.

A color display device that displays broadcast programs is used to monitor or set control operations of this automatic broadcast control device.

In this color display device, even when displaying characters in red or blue, color subcarriers are used as in the above-mentioned television broadcast.

When displaying characters in color using this color subcarrier, a special color signal generation device is required.

That is, since the character to be displayed is thin, the character signal obtained by scanning this character is derived as a narrow signal.

In order to display this character signal in color, the color subcarrier must be set at a phase corresponding to a predetermined color within this narrow width.

Conventionally, a color signal generating device shown in FIG. 1 has been used to display this character signal in color.

That is, the phase of the 3.58 MHz color subcarrier introduced into the input terminal 2 is matched with the phase corresponding to colors such as red, green, blue, yellow, etc. by the plurality of phase shifters 4, and the color signal and the legate circuit 6 be introduced.

A control signal specifying each color is derived from a control signal generator 8 to this gate circuit 6, and the gate circuit 6 of a predetermined color is made conductive and a color signal is introduced into the mixer 10.

In this device, when the character "A" shown in FIG. 2A is displayed in red, a character signal specifying the color red is generated from the control signal generator 8, and the gate circuit 6 for red is made conductive.

Therefore, in this device, all color signals corresponding to display colors are generated in advance, and these color signals are derived by character signals to obtain color signals.

However, in this color signal generation device, phase shifters 4 and gate circuits 6 are required for each color that can be displayed, and phase shifters 4 and gate circuits 6 for colors other than those for display colors must also be operated at all times. However, there are disadvantages in that the circuit configuration is complicated and a large amount of power is required.

This invention eliminates this drawback, and uses color designation signals for characters (including numbers, symbols, etc.) to be displayed.
The phase of the color subcarrier is made to match the phase of the displayed color by a variable phase shifter, and this color subcarrier is selectively derived using a character signal.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6.

FIG. 3 shows the circuit configuration of the control signal generator 12.
is provided with three input terminals 121, 122° and 123.

Each of these input terminals receives digital color designation signals 14, 16, 16, and 14 indicating the primary colors of red R1 green G and blue B shown in FIG.
18 will be introduced.

This color designation signal is formed from the signal 22 in FIG. 2 corresponding to the frame 20 of the character "A" shown in FIG. 2a, and is generated in accordance with the displayed character color.

Note that FIG. 2c shows the character signal 2 obtained by scanning 23 in FIG. 2a.
It is 4.

Therefore, when the display color is red, the red designation signal 14 shown in FIG. 5 is introduced into the red input terminal 121 of the control signal generator 12.

Further, in the case of yellow display, a red designation signal 14 and a green designation signal 18 are respectively introduced.

This control signal generator 12 is constructed as shown in FIG.

The color designation signals from each input terminal 121, 122, 123 are introduced into the color display signal generation circuit 124, and from this color designation signal, red R1 green G, blue B, yellow Y, cyan C, magenta M
Each display color signal is generated, and this display color signal is introduced into each color drive circuit 126.

The output of each color drive circuit 126 operates a switch element 130 in a series circuit of a resistor 128 and a switch element 130 provided separately.

Note that the resistance value of each resistor 128 is set corresponding to each color.

One end of each resistor 128 is connected in common, and the common resistor 1
32 to a predetermined potential source, and an output terminal 134 is provided from the common connection point.

Therefore, in this control signal generator 12, a display color signal corresponding to the color of the color designation signal is generated, and by operating the switch element 130 according to this display color, the output terminal 134 is connected to the resistor 128. A predetermined voltage corresponding to the display color is introduced by voltage division with the resistor 132.

The output voltage from this control signal generator 12 is applied to a control terminal 30 of a variable phase shifter 28 to which the 3.58 MHz color subcarrier from the oscillator is introduced at the input terminal 26.

This phase shifter 28 has input and output terminals 26 as shown in FIG.
．． A coil 170 in which a variable capacitance diode 168 is connected between capacitors 164 and 166 respectively connected to
A variable delay line device is used in which a control terminal 30 is provided between a capacitor 164 and a coil 170.

When the output voltage of the control signal generator 12 is applied to the control terminal 30, the capacitance of the variable capacitance diode 168 changes and the color subcarrier is delayed.

In other words, the phase of the color subcarrier is matched with the phase corresponding to the display color.

The color subcarrier that matches the phase of this display color is introduced into the gate circuit 34.

This gate circuit 34 has a control terminal 36 into which a character signal 24 of a character to be displayed as shown in FIG. Ru.

The color subcarrier at the output terminal 38 is combined with the character luminance signal and introduced into a color display device (not shown) to display the character in color.

Therefore, when the character "A" shown in FIG. 2A is to be displayed this spring, the control signal generator 12 receives the digital red designation signal 14 shown in FIG. 2S at the optical input terminal 121.

Since only the red designation signal 14 is introduced by the control signal generator 12, the red drive circuit 126 operates, and an output voltage corresponding to the red color set by the resistor 128 and the common resistor 132 is derived.

This output voltage causes the phase of the color subcarrier to shift to the phase shifter 28.
The gate circuit 3 matches the phase corresponding to the red display.
4 will be introduced.

In the gate circuit 34, a color subcarrier is derived according to the character signal, and a red "A" is displayed on the color display device.
Characters are displayed.

Further, when displaying the letter "A" in yellow in FIG.
operates, and an output voltage corresponding to yellow is derived.

The operation of the phase shifter 28 based on this output voltage is performed in the same manner as described above, and a color subcarrier having a phase matching that of yellow is derived from the gate circuit 34.

Therefore, according to the present invention, a signal whose phase of a color subcarrier should match the phase of a display color is obtained from a color designation signal of a text color to be displayed, and this color subcarrier is selectively derived from a character signal. This eliminates the need to provide a large number of phase shifters 28 for setting the phase of color subcarriers and gate circuits 34 for deriving color subcarriers based on character signals, corresponding to the display colors, and the circuit configuration can be simplified. Text can be displayed in color without requiring power consumption.

In addition, in the above explanation, the display of characters was explained, but the display is not necessarily limited to this character display.
It is obvious that this method can be applied to displaying numbers, symbols, etc.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a conventional color signal generating device, FIG. A circuit diagram showing an embodiment of the color signal generating device according to the invention, FIG. 4 is a circuit diagram showing a part of FIG. 3 in detail, and FIG.
A waveform diagram explaining the operation of the device shown in FIG. 3, and FIG.
It is a circuit diagram showing a part of the figure in detail. In the figure, 12 is a control signal generator, 16 is a variable phase shifter,
20 is a gate circuit.

Claims (1)

[Scope of Claims] 1. A control signal generator into which a color designation signal of a character to be displayed is introduced and which derives a control signal corresponding to the phase of the display color of this character, and the control signal and color from this generator. a variable phase shifter for introducing a subcarrier and shifting the phase of the color subcarrier to the phase of the display color according to the control signal; and a gate circuit for selectively deriving the color signal according to the character signal of the character.