JP3061851B2 - Display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for character / graphic information such as teletext (teletext) and videotex.

2. Description of the Related Art A standard called Level A has already been put to practical use in teletext broadcasting by the coded transmission system, and its display screen is composed of a screen of 248 dots in the horizontal direction and 204 lines (dots) in the vertical direction. The minimum unit of the coloring unit is 4 × 4 dots vertically and horizontally of the dot pattern.

For character / graphic information such as teletext, a television receiver is usually used as a display device. For this reason, when displaying the above-mentioned screen, two methods are used.

The first method is a method of making a pseudo non-interlace by performing scanning twice per frame using only one of the first and second fields.

The second is a method called pairing for displaying the same screen in both the first and second fields.

Whereas a normal television receiver forms one frame with 525 scanning lines and generates it at a cycle of 30 Hz, an EDTV called clear vision generates a frame at a cycle of 60 Hz. For this reason, when the above-described level A screen is formed on an EDTV, the same signal is normally displayed twice for two scanning lines, which causes a problem such as flicker. However, it looks like a standard television receiver. In the second method.

FIG. 6 shows an example of an oblique line when the same signal is displayed twice as described above. When displaying on a display device such as a teletext or videotex, jaggedness peculiar to the digital processing screen occurs in diagonal lines as shown in FIG. For this purpose, a process called an interpolation process (smoothing or rounding) is performed to perform dot interpolation.

A smoothing method in a conventional display device will be described below with reference to FIG. FIG. 7 shows an example of a display interpolation device in Japanese Patent Application Laid-Open No. 63-59153.

In Figure 7, FI field indication signal, l ₁ is one of the display signals for any dot any line, CK1 is dot clock signal, a clock signal twice the frequency of the dot clock CK2. Reference numeral l2 denotes a display signal obtained by shifting the display signal l1 by one dot section by the dot clock signal CK1 in the shift register 1, l3 denotes a display signal obtained by delaying the display signal l1 by one line in the line memory 2, and l4 denotes the display signal l3 by the shift register 3. Is a display signal shifted by one dot section by the dot clock signal CK1. These field indication signal FI, display signals l1, l2, l3, l4 and dot clock signal C
The six kinds of signals of K1 are used as address signals of the storage means 4, and the storage means 4 changes the output pattern to change the display signal s.
Outputs 1, s2. The display signal s2 is shifted by one clock of the clock signal CK2 having twice the frequency of the dot clock signal CK1 by the shift register 5, and outputs a display signal s3 obtained by delaying the display signal s2 by 0.5 dot. This display signal s3
Is ORed with the display signal s1 by the OR circuit 5,
Outputs the interpolated signal s0.

When the oblique line pattern shown in FIG. 6 is interpolated by the apparatus shown in FIG. 7, the hatched portion is interpolated and displayed as shown in FIG.

In teletext broadcasting, a character display frame of 24 dots vertically and 16 dots horizontally is set for standard characters, and a coloring unit is set for a minimum of 4 × 4 dots. The coloring includes a foreground color (FG) for coloring the dot pattern and a background color (BG) for coloring other character frames.

FIG. 9 shows a conventional example of a display device in which a coloring function is added to the display interpolation device shown in FIG. In FIG. 9, reference numeral 7 denotes a block of FIG. 7, which is an interpolation signal generator. Reference numeral 8 denotes a dot pattern memory / generation unit that stores a dot pattern and performs readout generation in accordance with a synchronization signal, and generates a serial signal 11. 9 is a foreground color memory / generation unit.
The G, B, and luminance signals FR, FG, FB, and FZ are generated by matching the display timing with the serial signal l1. Reference numeral 10 denotes a background color memory / generation unit, and each of the R, G, B and luminance signals BR, B
G, BB and BZ are generated by matching the display timing with the serial signal l1. 11 indicates FR, FG, FB and FZ when the output signal s0 of the interpolation signal generator 7 is present, and BR, BG and BB when there is no output signal s0.
And BZ, and generates switching signals as SR, SG, SB and SZ. Reference numeral 12 denotes a video synthesizing unit that performs luminance conversion on the SR, SG, SB, and SZ signals and outputs the resulting signals as R, G, and B signals.

When the display device shown in FIG. 9 is used, interpolation as shown in FIG. 11 is performed in the case of a character pattern as shown in FIG.

Problems to be Solved by the Invention In the conventional display device, as shown in FIG. 12, the dot pattern is recorded by inverting the polarity by designating the pattern polarity, and the foreground and background colors are apparently inverted and displayed. In the interpolation process for displaying a character designated to be inverted (inverted character), the portion other than the inverted character is interpolated, and an interpolation process different from the original intention is performed as shown in FIG. However, there is a problem that the function for making the character easier to read has an adverse effect, and the readability of the character is significantly impaired.

In addition, in the case of the character broadcast level A, for example, in the case of the inverted character, a method of simply exchanging the foreground color and the background color by software processing and recording from the viewpoint of the flushing polarity, concealment display, and the like cannot be used.

Means for Solving the Problems In order to solve this problem, a display device of the present invention includes a memory for storing a character display frame indicating a polarity inversion character section, and a signal indicating a polarity inversion section from the memory. An interpolation signal generator having means for switching the interpolation processing method is provided.

Further, the display device of the present invention switches between the interpolation processing method when a memory indicating the presence / absence of flashing, the phase of flashing, the presence / absence of concealment, and the polarity inversion character section, and when a signal indicating the polarity inversion section is input from this memory. An interpolation signal generator having means is provided.

According to the present invention, with the above-described configuration, the interpolation processing method at the time of normal display and at the time of polarity inversion can be switched, so that the inverted characters at the time of polarity inversion become thin and difficult to see. Can be prevented.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a display device according to a first embodiment of the present invention, and FIG. 1 is an embodiment of an interpolation signal generator in the display device. In FIGS. 1 and 2, those having the same numbers as those of the conventional example shown in FIGS. 7 and 9 have the same functions, and detailed description thereof will be omitted.

In FIG. 2, reference numeral 13 denotes a means for storing signal contents for generating an interpolation pattern, and includes a field instruction signal FI, a display signal 11, a shift signal l2, l3, l4, and a dot clock signal CK.
Arbitrary output signals s1 and s2 are generated according to the input signal pattern of 1 and the POL signal indicating the inverted character display frame section. That is, the interpolation signal can be switched depending on the presence or absence of the inverted display character.

In more detail, if characters are displayed normally, POL
The signal is set to a low level (0), and the interpolation process employs a method of increasing the area of the FG, and interpolation is performed to fill the jagged portion of the FG. If the characters are highlighted, set the POL signal to high level (1), and in the interpolation process, reduce the area of the FG part and increase the area of the BG to reduce the jagged part of the FG further. Interpolation is performed.

FIG. 4 shows a specific example of interpolation at that time. In the case of FIG. 4 (a), the FG is an oblique line to the upper right, and the right side of the FG is cut off on the upper side and the left side of the FG is cut off on the lower side so as to reduce the area of the FG portion. Interpolate BG. In the case of FIG. 4 (b), the FG is a diagonal line descending to the right. In order to reduce the area of the FG portion, the left side of the FG is cut on the upper side and the right side of the FG is cut on the lower side. Interpolate BG.

In FIG. 1, reference numeral 14 denotes a character frame memory / generation unit that stores a character display frame in a polarity inversion section and generates a character frame signal synchronized with a dot pattern. Reference numeral 15 denotes an interpolation signal generator shown in FIG. When the POL signal output from the character frame memory / generator 14 is low level, the interpolation signal generator 15
Uses a normal character display interpolation method, and in the case of the pattern shown in FIG. 10, the interpolation shown in FIG. 11 is performed. When the POL signal output from the character frame memory / generation unit 14 is at a high level, the interpolation signal generation unit 15 employs an interpolation method for displaying inverted characters, and the storage means 13 of the interpolation signal generation unit 15 stores the fourth
The operations shown in FIGS. 12A and 12B are performed, and in the case of the pattern shown in FIG. 12, the interpolation shown in FIG. 5 is performed.

In this way, the character display frame of the polarity inversion section is stored and read out, and the character frame memory / generation unit 14 is provided, and the interpolation signal is switched and displayed according to the presence or absence of the inversion character. Interpolation processing method is switched, and conventionally, when performing solid character interpolation display with polarity inversion specified, the pattern that should become a character is not interpolated, and dots are missing or characters are seen thinner. This makes it possible to display characters and graphics more effectively.

FIG. 3 is a block diagram of a display device according to a second embodiment of the present invention, in which components having the same numbers as those of the conventional example shown in FIG. 9 have the same functions, and detailed descriptions thereof will be omitted. .

In FIG. 3, the interpolation signal generator 15 operates in the same manner as in FIG. 16 memorizes each attribute of flashing, concealment and inverted polarity character, and FLA determines whether flashing
A display attribute memory / generation unit that generates a signal, a flushing phase by an FPH signal, presence / absence of a concealment by a CON signal, and presence / absence of a polarity inversion character by a PLO signal. Reference numeral 17 denotes a flushing generation unit that generates a flushing signal of 1 Hz in accordance with the phase of the FPH signal when the FLA signal is on. Reference numeral 18 denotes a display attribute memory / generation unit 16 for displaying a signal from the interpolation signal generation unit
This is a gate for generating an appropriate signal from the switching unit 11 under the control of the CON signal from the controller and a signal from the flushing generation unit 17. In addition, the display attribute memory / generation unit 16
The PCL signal indicating the inverted character display frame section generated from is input to the interpolation signal generator 15, and as described above, the interpolation method is selected depending on the presence or absence of the inverted display character.

Normally, the display attribute signal generator of the teletext is the same as a 4 × 4 coloring unit, and each of the foreground and background memories stores 1-byte data of a 2-color block. However, the display attribute memory uses only 3 bits in one byte and 3 bits in total depending on the presence / absence of flushing, the presence / absence of concealment, and thus there is a margin of 1 bit per colored block.

Effect of the Invention As described above, according to the present invention, a memory for storing a character display frame to be displayed with polarity inversion is newly set, and an interpolation signal is switched and displayed according to the presence or absence of an inverted character.
When a character figure with polarity reversal specified as in the past is interpolated and displayed, the pattern that should become a character is not interpolated and dots are missing or characters are no longer seen thinner, making character figures more effective An extremely excellent effect such as display can be obtained.

It should be noted that the present invention does not specify the interpolation method itself, but has an object to effectively display a character or graphic whose polarity is inverted. Also, a display device performing an interlace display was used as an embodiment of the present invention,
It goes without saying that the present invention is also included in the case of double-speed scanning such as EDTV, so-called double-density display device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a display device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing an example of an interpolation signal generator in the display device, and FIG. FIG. 4 is a block diagram of a display device according to a second embodiment of the invention, FIG. 4 is a diagram for explaining an interpolation operation at the time of polarity inversion of the present invention, FIG. 5 is a diagram showing a display example at the time of polarity inversion, and FIG. FIG. 7 shows a conventional display example, and FIG.
FIG. 8 is a block diagram of a conventional example of an interpolation circuit, FIG. 8 is a diagram showing a conventional interpolated display example, FIG. 9 is a block diagram of a conventional display device, FIG. FIG. 11 is a diagram showing a display example after interpolation, FIG. 12 is a diagram showing a display example before interpolation of reversed characters, and FIG. 13 is a diagram showing a display example after interpolation of reversed characters. 1, 3, 5 ... shift register, 2 ... line memory, 6 ...
... OR circuit, 8... Dot pattern memory / generation unit,
9: Foreground color memory / generation unit, 10: Background color memory / generation unit, 11: Switching unit, 12: Image synthesis unit, 13: Storage means, 14: Character frame memory / generation unit, 15 …… Interpolation signal generator, 16… Display attribute memory and generator, 17… Flashing generator, 18… Gate.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-208795 (JP, A) JP-A 64-23094 (JP, U) Television technology, 34, July issue, July 1, 1986 , Electronic Technology Publishing Co., Ltd., p27-31

Claims (2)

(57) [Claims] 1. A first memory for storing and displaying and reading out a dot pattern such as a character graphic, and a second memory for storing and displaying and reading out a coloring (foreground color) when a dot pattern is present in an arbitrary coloring unit. A third memory for storing and displaying and reading out the coloring (background color) when there is no dot pattern in an arbitrary coloring unit; and a fourth memory for storing and displaying and reading out a character display frame indicating an inverted character section in an arbitrary coloring unit. And interpolating signal generating means for outputting an interpolating signal for interpolating the same dot pattern read out from the first memory in both fields of the first field and the second field for each field. Interpolation signal generation means generates an interpolation signal according to a character display frame signal read out from the fourth memory for each field, and displays a character indicating the inverted character section. An interpolation signal in the absence of a signal is subjected to interpolation processing to increase the area of the foreground color signal read from the second memory, and an interpolation signal in the presence of the character display frame signal is stored in the third memory. The area of the background color signal read from the second memory is increased, and the area of the foreground color read from the second memory is reduced, so that interpolation processing suitable for each of normal time and polarity inversion is performed. Display device. 2. The memory according to claim 1, wherein the fourth memory stores information on the presence / absence of flushing, a flushing phase and a concealment, which are display attributes, in arbitrary coloring units, and a character display frame indicating an inverted character section, and reads and displays the character display frame. The display device according to claim 1.