JPS6075877A - Improved character coloring circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a character/graphic color signal correction circuit, and is particularly applicable to a data display system that reproduces character/graphic data (hereinafter referred to as data) using a color television set. It is suitable for this purpose.

[Background technology and its problems]

2. Description of the Related Art In recent years, with the spread of color television receivers, data transmission systems have been developed that use color television sets as display devices to reproduce news and various other information. The first example is a cabtain system (which transmits data stored in a data center via a telephone line to a color television set installed in a subscriber's telephone terminal and reproduces color image information). Character and patte
rnTelepbone Access lnform
ation Network System). A second example is still image broadcasting, which utilizes television broadcasting and broadcasts data by inserting it into the blanking period of the television signal, and this data is received by a color television set and reproduced as color image information. .

By the way, when trying to produce color image information based on data using a color television set, when coloring a small area such as a line or part of a character (hereinafter referred to as a linear part), the tap root must become small. The color tends to become lighter as the color increases, and there is virtually no color in the linear portion with a width of one dot, which is the smallest unit of the display screen.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and is intended to improve the problem that color does not stick to thin linear parts.

[Summary of the invention]

In order to achieve such an object, the present invention provides that, when a color signal corresponding to a linear portion with a width of one dot, which is the minimum display on a display screen, arrives, the time width is changed to a linear portion with a width of two dots or more. Expand to a time width corresponding to .

〔Example〕

Embodiments in which the present invention is applied to a captain system will be described in detail below with reference to the drawings. As shown in Figure 1, this data transmission system uses a line switch (4) at the terminal of a telephone line (3) installed between a telephone subscriber's telephone (1) and a telephone exchange (2). This line switch (4
), data transmitted from the data center (5) through the telephone exchange (2) and telephone line (3) can be received and displayed by the information receiving device (6).

The information receiving device (6) receives information from a signal processing circuit (8) based on the information selection input from the keyboard (8) via the variable-modem (7) connected to the line switch (4). The command No. 16 obtained in step 9) is sent up the telephone line (3) as a data signal. At this time, the data returned from the data center (5) is again supplied to the modem (7) as a lower data signal through the telephone line (3), demodulated, and given to the signal processing circuit (9).

Here, the data is decoded in the image signal reproducing circuit (10) and color signals R, G, B, foreground type 5
It is converted into an image signal including the number YD and the like. Note that when the foreground signal YD is at the logic "1" level, the brightness and color of the area where characters are to be displayed (this is called the foreground) is changed from the brightness and color of the area where characters are not displayed (this is called the background) other than this area. The character signal is generated during the time width of the foreground signal YD. .

However, the decoded color signals R, G, and B are sent to the video signal forming circuit together with the foreground signal YD and the signal after the time width correction in the color signal correction circuit (11) having the configuration shown in FIG. A video signal obtained by RF modulation is input to and displayed on a television camera (13).

The color signal correction circuit (11) is connected to the television set (13).
) When the color signals R, G, and B arrive with a time width corresponding to a 1-bit linear portion on the display screen, the time width is expanded to a time width corresponding to a imaginary portion with a width of 3 dots. It has the following structure. That is, the color signal correction circuit (11) includes time width correction circuits (15R), (15G), (15B) corresponding to the color signals R, G, B and the foreground signal YD.
(15Y) and a color signal output circuit (16), each time width correction circuit m (15R).

(15G), (15B> and (15Y) are the sequential pulse generation circuit (17) and the logic output circuit (18), respectively.
).

As shown in FIG. 3, each J+@order pulse generation circuit (17) has a shift register circuit (22) having a four-stage circuit configuration that receives input signals I (consisting of R, G, B, and YD), respectively. When an input signal of logic "1" with a time width corresponding to one dot width arrives at the input terminal as shown in the 41st prisoner, the first
This logic "1" signal is read into the first stage circuit (23A) by the th clock pulse CL. This first stage circuit (
The logic "1" signal read into the second.
Every time the third... clock pulse CL arrives at the shift register circuit (22), the second stage circuit (23
B), the third stage circuit (230), and the fourth stage circuit (6D) are sequentially shifted, thus FIG. 4 ω), (C),
(Lll, shift register circuit (η) as shown in @
1st. Second. Third. 4th stage circuit (23A), (23B
), (23C), and (D) have a clock pulse C at the output terminal.
Output pulses S2, 83, with the same rising width as the period of L.
84, S5 is generated.

Here, the period of the clock pulse CL is equal to the time width corresponding to the width of the linear portion of one dot, that is, 175 ns.
(i.e. 5.727 MHz) and therefore the output pulses 82, S3, S4, S
The rising period of 5 corresponds to 4 dots which are sequentially applied to the dot corresponding to the input signal 2 when viewed on the display screen.

Input signal ■ at the input end of the shift register circuit (22);
Each stage circuit (23A), (23B), (zic
).

(23D) output pulses S2, S3, S4,
S5 is applied to a logic output circuit (18). The logic output circuit (18) receives the input No. 4N I as the first input signal 81 via the inverter (24A), and outputs the output signal of the first stage circuit (23A) as shown in FIG. a three-man power AND circuit (25) which receives directly as a second input signal S2 and receives the output pulse of the second stage circuit (-23B) as a third input signal S3 via an inverter (24B); The output pulse of the circuit (23B) is received as the first input signal S3 via the inverter (26A), the output pulse of the three-stage circuit (23C) is directly received as the second input signal S4, and the fourth stage circuit (23C) is directly received as the second input signal S4. 23D) via an inverter (26B) as a third input signal S5.

The outputs of the AND circuits (25) and (27) are the second stage circuit (
23B) along with the output pulse S3 of the three-person Chaor circuit (28
) through time width correction circuits (15R), (15G).

As the output of (15B) and (15Y), the color signal output circuit (
16) Given in (Fig. 2).

In this embodiment, the logic output circuit (18) actually consists of an inverter and a NAND circuit, as shown in FIG. 2 with the same reference numerals assigned to corresponding parts as in FIG. Incidentally, the three-person Chaor circuit (A) in Figure 3 is the NAND output function of the NAND circuit (31), which is the inverted output function of the NAND circuits (29A) and (29B) and the inverted output function of the inverter (3o) in Figure 2. By combining the two, OR output-like functionality is achieved as a whole.

Time width correction circuit (15R), (15G), (15B).

The output of (15Y) is provided in the color signal output circuit (16) by switching transistors (3
1R), (31G), (31B), (3
1Y) buffer (32K), (32G), (32B)
.

(32Y). However, the NPN emitter floor transistor of the foreground signal YD (
31Y), the output of the time width correction circuit (15Y) is hi
During OJ, the resistors (33R) and (33G) enter a high impedance state and transmit a relatively low voltage.

PNP type open collector transistor (31R) for color signals R, G, B via (33B), (31G)
.

(31B) to pull it down to a low voltage level. This transistor (31R).

(31G), (31B) reduce the internal impedance to a low level and send out the color signal ktLl (JL # BL) at a low voltage level (i.e. dark level) from the emitter, thereby determining the brightness and brightness of the background ground. Generate color.

On the other hand, the NPN transistor (31Y) of the fog ground signal YD enters a low impedance state when the output of the time width correction circuit (15Y) is logic "1" and transmits a relatively high voltage to the resistor (33R) ( 33G).

Transistors (31R) and (3
1G).

(31B). At this time, the transistors (31R), (31G), and (3113) are in a brown impedance state, and a positive voltage Reherno voltage is applied from the emitter side to a relatively slow level color signal %+01.
* Send as BL, which generates shift or ground brightness and color.

Thus, time width 16 positive circuits (15R), (15G).

After the color signals kcL+UI, +BL of the level corresponding to the logic "1" or "0" output of the (1541) are adjusted in brightness by the foreground signal K, the video signal is output from the color signal output circuit (16). (FIG. 1). The video signal forming port ri & (12) receives this logic "1" or "0" color signal Rx, r CrTJe B
rJ is received by a matrix to produce color difference signals R-Y and B-Y, each of which modulates a carrier wave with a double-balanced modulator. This modulated output is mixed with a luminance signal, a burst signal, and a signal to create a composite video signal, which is then modulated with, for example, a two-channel carrier wave using an RF modulator to create a high-frequency signal similar to a television broadcast wave. The output of the signal processing circuit (9) is applied to the television set (13), thus displaying an image based on the data.

In the above configuration, the time width correction circuits (15R) to (1
The Wtem output circuit (18) of the 5Y) outputs a logical output W expressed by the following logical formula to the outputs 81 to S5 of the 1-order pulse generation circuit (17) (FIG. 3).

W=S1 @S2・83 +S3 +S3・S4・S5
(1) However, based on the lower data signal from the modem (7), the output of the image signal reproducing circuit (10) is, for example, the decoded color signal R (therefore, the pulse S1). becomes logic “1” for a time corresponding to the linear part of 1 bit (see Fig. 4).
A>), the shift register circuit (22) performs a shifting operation every time corresponding to one bit. Therefore, the first stage circuit (Z3A) to the fourth stage circuit (Z(D) sequentially perform one dot equivalent time). Outputs 82 to S5 which become logic "1" are obtained during (
4th drawing) to ■), thereby causing the output terminal of the logic output circuit (18) to output a logic "L" for a period of 3 bits based on the above-mentioned formula (1) as shown in the 4th drawing. is sent out as the output of the time width correction circuit (15R). Therefore, the chrominance signal output circuit (16) outputs a chrominance signal RI whose rise time width is expanded to a time equivalent to 3 bits.

At the same time, in the time width correction circuit (15Y), if the logic level of the foreground signal YD becomes logic "1" for the time equivalent to 1 bit, the logic "1" for the time equivalent to 3 bits becomes "1".
By sending the output ``1'', the color signal RL of the character part is
*Foreground brightness can be added to GI, +BL.

Incidentally, regarding FIG. 4, the time T1 when the color signal R arrives
Outputs S2, 8 of the shift register circuit (22) sequentially from
3, time T when S4 and 85 are logic “1”
Logic output W at 2, T3, T4, T5
If we look at , 51=1 for time T1, so
W=1・0・0+0+0・0−0=0 ・・・−・・(
2) Since 52=1 for time T2, W=1・1
・1+0+1・0・1=1 ・・・・・・(3) Time T
Since 53=1 for 3, W=1・0・O+1+
0・0・1=1 (4) Since 54=1 for time T4 K, W=1・0・1+O+1・1・1
=1 ・・・・・・(5) Since 55=1 for time T5, W=1-0・1+O+1・0・0=0 ・・・・・・(
6). Therefore, the output W of the logic rlJ can be obtained during the time T2-T3.

On the other hand, if the decoded color signal R becomes the logic rlJ for a time corresponding to 2 dots, the output W will change to the dots of the decoded color signal R based on the output S3 of the sequential pulse generation circuit (17). logic rl for a time corresponding to the length of
It is possible to obtain an output W that is J.

The above operation is performed in exactly the same way for the decoded color signals G and B.

In the above description, an embodiment in which the present invention is applied to a captain system has been described, but the present invention is not limited to this, and can be widely applied to still image broadcasting and other applications where data is displayed using a color television set.

Furthermore, in the above description, the composite video signal VID obtained based on the output of the color signal correction circuit (11) is applied to the antenna terminal of the television set after RfI' modulation. Even if you connect it directly to the state detection output terminal of the television set without connecting it, you can obtain the same effect as in the case described above. You should give it to

〔Effect of the invention〕

As described above, according to the present invention, when a color signal corresponding to one dot arrives on the display screen, the width of the signal is expanded and displayed on the display screen. Even narrow linear parts of character figures can be reliably colored.

one! By expanding the time 1- to the equivalent of 3 bits as in the case of the above-mentioned embodiment, it is possible to reliably color even narrow linear parts without changing the color scheme of the laughing image. I can do it.

Note that in order to select a time width other than that corresponding to three dots, the logic conditions of the logic output circuit (18) may be changed as necessary, and the above-mentioned color correction effect can also be obtained in this way.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a data transmission system to which a character/figure color signal correction circuit according to the present invention is applied, Fig. 2 is a connection diagram showing the color signal correction circuit, and Fig. 3 shows its time width correction circuit. The connection diagram and FIG. 4 are signal forming diagrams for explaining the operation. (1)...telephone, (2)...-telephone exchange, (4)
... Line switch, (5) ...-Data center, (6
)...Information signal device, (7)...Modification v3 device, (
8)...keyboard, (9)...-signal processing circuit, (
10)...Image signal reproducing circuit, (11)...Color signal correction circuit, (12)...Video signal forming circuit, (13)...
...-Rikira Television Set, (15R) ~ (15
Y)...Time width positive circuit, (16)...Color signal output circuit, (17)...Sequential pulse generation circuit, (18)
...Logic output circuit, (21) ...Waveform shaping circuit. Applicant's agent 1) Kei Hajime

Claims (1)

[Claims] In a day/evening display system that displays a color image that complements the above data by creating a video signal from the image signal reproduced from the data and feeding it to the television station, a video signal is generated based on the color signal decoded from the above data. A sequential pulse generation circuit that generates a sequential pulse to each of a plurality of output terminals to sequentially syntify one dot on a display screen at each time, and a time for converting a dot to two or more dots using the output signals of the plurality of output terminals as input. 1. A character/figure color signal correction circuit comprising a logic output circuit that sends out a logic output that rises during a period of time, and uses the logic output as a primary color signal to obtain a color difference signal used in producing the video signal.