JPS5857748B2 - Display control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display control method, and more particularly to a control method for controlling the brightness of displayed characters in a CRT display device. Display devices are widely used.

Recently, there have been many display devices that can display not only alphanumeric characters and kana characters but also complex characters such as kanji.

For these characters or figures, one section, that is, the area required to display one character, is divided into m x n dots (m in the horizontal direction and n in the vertical direction), and the brightness of the dot position corresponding to the displayed character is increased. will be displayed.

When displaying characters with simple shapes such as alphanumeric characters and kana characters, the display brightness is approximately constant even if the characters are different, but when characters with simple shapes and complex shapes coexist, such as kanji. In some cases, the display brightness becomes thicker (changes) depending on the font.

Furthermore, even within one character, the brightness differs between parts with a high dot density and parts with a small dot density, making it extremely difficult to see.

In general, CRT display devices perform raster scanning in the horizontal direction and display by modulating the brightness of the corresponding positions of characters using dot signals, but video amplifiers for brightness modulation are usually relatively inexpensive to achieve low cost. A narrowband amplifier is used.

For horizontal line segments, a continuous dot signal is obtained, so the signal frequency is equivalently lower and sufficient brightness is obtained, but for vertical line segments or isolated dots, a single dot signal is obtained in the scanning direction. Since only dot signals are obtained, there is a drawback that corresponding line segments, isolated points, etc. become dark.

In order to eliminate this drawback, it is conceivable to increase the input signal to the video amplifier only when the dots are not continuous in the horizontal direction.

However, according to this idea, the diameter of the display dot is determined by the pulse width of the dot signal and is constant for all dots, so as shown in the display example of FIG. has the disadvantage that it is displayed as a dotted line and the brightness is also dark.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display control system that makes it easy to see displayed characters, and in particular, to provide a display control system that eliminates the disadvantage that isolated points and diagonal parts of displayed characters are difficult to see.

According to the present invention, the diameter of a dot in a particular part of a displayed character, such as an isolated dot or a diagonal part, is made larger than in other parts of the same character, thereby making the displayed character easier to see.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing an example of a display character according to an embodiment of the present invention, in which the diameter of the dots in the diagonal portion 1 of the display character is set to be fi times the diameter of the dots in the other portions.

That is, diagonal line segment 1 in FIG. 1 becomes diagonal line segment 1 in FIG. 2, and although the width of the diagonal line segment is thicker, it is easier to see than the displayed figure in FIG. 1.

FIG. 3 is an explanatory diagram for detecting dots forming diagonal line segments.

In Figure 3 a, b, and c, X-1, X, X+1 and Y-1, Y, Y+※※1 are the X coordinates of the dots, respectively.
Indicates the Y coordinate.

Scanning is performed in the direction of the arrow, and when a dot is detected, the dot signal is applied to the video amplifier in synchronization with the scanning signal.

The dot signal is expressed by X and Y coordinates. be done.

When the dot signal (Y) is at the intersection with a vertical line segment or a horizontal line segment, it is not an element of the diagonal segment There are no adjacent dots on the top, bottom, left and right sides of the dot, and there is at least one adjacent dot in the diagonal direction.

This condition can be expressed as a logical expression as shown in equation (1).

However, (X) means that there is no dot at the coordinates X and Y.

The symbols are logical product and logical sum symbols, respectively.

In FIG. 3A, the dot (X) of interest is an element constituting a diagonal line segment, since there is a dot () diagonally above and to the right of X+1, and no dots exist above, below, left and right -1.

The bit (Y) in FIG. 3 is also an element of a diagonal line segment.

However, the dragon in Figure 3C
X+1 Dot () has a dot () diagonally on the upper right side y-i X-1.

However, since there is a dot ( ) on the left, it does not satisfy equation 0) and cannot be an element of the diagonal line segment.

In this case, it is the intersection of the diagonal line segment and the horizontal line segment.

Only X+1 However, since dot () satisfies equation (1), it is diagonal -1 It becomes an element of a line segment.

If the diameter of a dot that satisfies equation (1) is expanded, for example, by eight times, it will become as shown in FIG.

That is, in the display pattern of FIG. 4, only the three dots forming the diagonal line segment are enlarged as shown by dotted lines.

Enlargement of the dot diameter can be easily achieved by controlling the focus control voltage of the CRT.

Next, a specific example of a circuit configuration for realizing equation (1) will be described with reference to FIG.

In FIG. 5, 51 is a shift register, 52 is an OR circuit, 53 is a NOR circuit whose output is II I If when all inputs are logic "10", and 54 is an AND circuit.

Dot information constituting characters or figures is stored in a known font memory (not shown), and dot information of characters or figures to be displayed is transferred from this font memory and stored in a refresh memory (not shown) for one screen. stored in ).

In a conventional CRT display device, dot information is transferred from the refresh memory to the video amplifier in bit series for each scanning line and displayed, but in the embodiment of the present invention, dot information is transferred from the refresh memory for each scanning line. is transferred to the shift register 51 in bit series.

Now, if the maximum number of characters displayed in the horizontal direction of the screen is 1, and the interval between character areas is d bits, then the shift register 51
The size of is 2(1(m+d)-d)+3 bits.

That is, 1(m+d)-d is the total number of bits on one scanning line.

The dot signal (y) to be displayed is 1 (m+d)- counted from the right end of the shift register 51 as shown in FIG.
It is taken out from the d+2nd position and applied to the video amplifier.

The left and right dot signals () and () adjacent to X-1 and X+1 are Y Y 1 (m
+d)-d-1-3 and l(m+d)-d-
It is taken out from the 1-1st position.

The vertically and diagonally adjacent dot signals are also taken out from the positions indicated in the shift register 51, respectively.

Therefore, the NOR circuit 53 selects the dot signal of interest (Y
), the output is II 1! It becomes l.

On the other hand, the OR circuit 52 selects at least one of the four dot signals at diagonal positions adjacent to the dot signal (Y) of interest.
If there is one, the output will be loud.

Therefore, the output of the AND circuit 54 becomes "1" only when the equation (1) holds true, that is, when the dot signal (Y) of interest is an element of a diagonal line segment (excluding intersection points).

This output controls the focus of the CRT display device to increase the diameter of the displayed dot.

The circuit configuration shown in Fig. 5 controls the diameter of the display dot, that is, the focal point, on the condition that there is no dot signal in the upper, lower, left, or right positions adjacent to the dot signal of interest, and that there is a dot signal in the adjacent diagonal position. However, only the condition that there are no dot signals at the adjacent upper, lower, left, and right positions may be used.

In this case, there is an advantage that not only the diameter of the diagonal line segment but also the diameter of the isolated point is enlarged, and the circuit configuration becomes slightly simpler as shown in FIG.

As explained above, according to the display control method of the present invention, when displaying complex characters and figures such as kanji on a CRT display device, the brightness of isolated points and diagonal lines is lower than that of horizontal lines, unlike in the past. It is possible to eliminate the drawback that the image is dark and difficult to see.

[Brief explanation of drawings]

FIG. 1 is a diagram showing -f11 of displayed characters when using a conventional CRT display device, FIG. 2 is a diagram showing an example of displayed characters when using the display control method of the present invention, and FIG. 3 is a diagram showing an example of displayed characters when using the display control method of the present invention. An explanatory diagram for detecting display dots constituting a diagonal line segment, FIG. 4 is a diagram showing an example in which only the diameter of the display dots constituting a diagonal line segment is enlarged, and FIGS. 5 and 6 are respectively FIG. 3 is a circuit diagram for realizing a display control method according to the present invention. 1.2 is the diagonal part of the character, and 51 is the shift register.

Claims (1)

[Claims] 1. In a CRT display device that displays characters or figures as a combination of dots by raster scanning, a shift register having a capacity of at least 2 scanning lines + 3 bits and into which information to be displayed is sequentially input, and a certain specific type of said shift register. With respect to the position, a detection circuit detects that the position of the register located at least on the top, bottom, left and right of the display screen stores that there is no display dot,
A display control method characterized in that a dot at the specific position is displayed larger than other dots in accordance with a detection signal from the detection circuit.