JP2000276113A - Display controller and program recording medium for the controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a thinning pattern of a new gradation other than a fundamental gradation only by storing plural kinds of thinning patterns corresponding to fundamental gradation levels as fundamental gradation display patterns. SOLUTION: A fundamental gradation display pattern table 27 stores plural kinds of thinning patterns corresponding to the number of the frames as fundamental gradation display patterns in accordance with fundamental gradation levels 1/2, 1/4. A gradation level decoder 22 controls the gradation level of display data. A fundamental pattern readout part 23 reads out plural kinds of patterns for every frame from the table 27 based on a discriminated gradation level and a frame count value. An ON-dot decoder 28 generates a new thinning pattern other than the fundamental gradation by repeating an operation determining whether a dot which is indicated by a line count value and a dot count value is to be turned ON or OFF for every dot unit by referring the fundamental gradation display patterns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control device for performing gradation display control in accordance with a frame thinning method, and a program recording medium therefor.

[0002]

2. Description of the Related Art Conventionally, a gradation display control method realized by a simple matrix color STN liquid crystal display device or the like is as follows.
Frame Rate Cont
rol) are known. This frame thinning method is
Normally, each dot is repeatedly turned on about 120 to 150 times per second. On the other hand, brightness is controlled by reducing the number of times, and gradation display is controlled by changing the time of on display. It was made. For example, at four gradation levels, the scanning time of the entire screen is one frame,
With four frames as one cycle, a gray scale display is realized by lighting once in four frames in the case of 階 調 gray scale and three times in four frames in the case of 階 調 gray scale. by the way,
In the frame thinning method, "flickering" (flicker) is likely to occur in the display in order to thin out the number of on-displays.
The display is shifted for each of the three primary colors RGB and the line. In this case, in order to suppress “flicker”, the determination is made according to a thinning pattern indicating which dot in one line is to be displayed on.

FIG. 8 illustrates a thinning pattern of 16 gradations. A thinning pattern (16 lines × 16 dots) for 16 frames is stored in the pattern data memory for each gray level. Here, “line” indicates the vertical direction of the liquid crystal display screen, “dot” indicates the horizontal direction of the display screen, and black circles in the pattern indicate ON dots.
Here, in the thinning pattern of the first frame of the 1/16 gradation level, the first line is the first dot, the second line is the second dot,..., The 16th line indicates that the 16th dot is displayed ON. It has a pattern.

FIG. 9 shows a configuration of a conventional display control section for performing display control in accordance with such a frame thinning method. A line counter 1, a frame counter 2, and a dot counter 3 correspond to a corresponding line count signal and frame count signal. The number of lines, the number of frames, and the number of dots are obtained by counting the dot count signal. The count values of the line counter 1 and the frame counter 2 are given to the memory address generation unit 4. The memory address generation unit 4 generates a memory address based on display data (gradation level data) from the display controller 5 and the count values of the line counter 1 and the frame counter 2. The thinning pattern is read from the pattern table memory 6 by accessing 6. The pattern table memory 6 stores 256 types (16 × 16) of thinning patterns in the case of 16 gradation display, and 768 types (256 × 16) in the case of displaying a different pattern for each of the three primary colors of RGB.
3) Store the thinning pattern. Here, the memory address has a 12-bit configuration, and the value of the frame counter 2 (4
), The value of the line counter 1 (4 bits), and the gradation level data (4 bits), and a pattern for one line is read from the pattern table memory 6. The comparing unit 7 compares the count values of the line counter 1, the frame counter 2, and the dot counter 3 with the pattern data from the pattern table memory 6. According to the result of the comparison, thinned data indicating ON / OFF of the dots is obtained. Output.

[0005]

However, in the case of this type, in the case of 16 gradation display, it is necessary to store 768 types of pattern data in the pattern table memory 6 as described above. As the number increases, the number of patterns increases, so that there is a disadvantage that the memory capacity increases and a circuit for selecting a pattern in accordance with a gradation level becomes complicated. SUMMARY OF THE INVENTION An object of the present invention is to generate a new gradation thinning pattern other than the basic gradation simply by storing a plurality of types of thinning patterns corresponding to the basic gradation level as a basic gradation display pattern. That is.

[0006]

The means of the present invention are as follows. According to the first aspect of the present invention, there are provided a plurality of types in which the ON display timing indicating which dot in one line is to be displayed ON is shifted for each of the number of frames and the number of lines in order to suppress "flickering" of the display according to the frame thinning method. In a display control device that performs gradation display control using a thinning pattern, a plurality of types of thinning patterns corresponding to the number of frames corresponding to a predetermined basic gradation level are stored as basic gradation display patterns. Pattern storage means, determination means for determining the gradation level of display data called as a display target, frame counting means for counting the number of frames, and display data gradation level and the frame determined by the determination means Based on the number of frames counted by the counting means, a plurality of basic floors are stored from the pattern storage means. A pattern readout unit for reading a display pattern for each frame unit, and a plurality of basic tone display patterns read by the pattern readout unit, which are sequentially processed in time series for each frame unit, thereby obtaining other than the basic tone. Pattern generating means for obtaining a new gradation thinning pattern. The present invention may be as follows. (1) There is provided definition information storage means for storing read definition information for defining a read order for reading out the plurality of types of basic tone display patterns at a predetermined timing for each of various tone levels. The definition information storage unit is searched based on the gradation level of the display data determined by the determination unit, and the basic gradation display pattern is obtained by referring to the corresponding reading order. Are sequentially read out according to. In this case, the definition information storage means defines read timings of a plurality of types of basic gradation display patterns and defines insertion of all dot-off patterns or insertion of all dot-on patterns between the basic gradation display patterns. It may be. Furthermore, the insertion position of the all-dot-off pattern may be defined so that the all-dot-off pattern does not continue for a predetermined number of frames. (2) When the thinning pattern for one screen is formed by repeating a common pattern element, the pattern storage means stores a matrix pattern forming the common pattern element as a basic gradation display pattern. (3) When a plurality of types of thinning patterns are stored in the pattern storage means for each of a plurality of types of gradation levels,
The pattern reading means selectively reads out each of the thinning patterns corresponding to a plurality of types of gradation levels for each frame unit according to a predetermined order.

According to the present invention, the gradation level of display data called as a display target is determined,
A plurality of basic tone display patterns are read out from the pattern storage means for each frame unit based on the tone level and the frame count value, and the read plurality of basic tone display patterns are read out for each frame unit. A thinning-out pattern of a new gradation other than the basic gradation is generated by sequentially processing in time series. Therefore, by simply storing a plurality of types of thinning patterns corresponding to the basic grayscale levels as basic grayscale display patterns, a new grayscale thinning pattern other than the basic grayscale can be generated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the data processing device. The CPU 11 is a central processing unit that controls the overall operation of the data processing device according to various programs. The storage device 12 includes a storage medium 13 in which an operating system, various application programs, a database, character font data, and the like are stored in advance, and a drive system thereof. The storage medium 13 is fixedly provided or removably mountable, and includes a magnetic / optical storage medium such as a floppy disk, a hard disk, an optical disk, a RAM card, and the like, and a semiconductor memory.
The programs and data in the storage medium 13 are loaded into the RAM 14 under the control of the CPU 11 as needed. Further, the CPU 11 receives programs and data transmitted from another device via a communication line or the like and stores them in the storage medium 13 or stored in a storage medium provided in the other device. Existing programs and data can be used via a communication line or the like. The CPU 11
The input device 15, the display device 16, and the printing device 17, which are input / output peripheral devices, are connected via a bus line, and the CPU 11 controls the operation according to an input / output program. The input device 15 has a pointing device such as a keyboard and a mouse for inputting character string data and the like and for inputting various commands. The display device 16 is a simple matrix color STN liquid crystal display device that performs full color display, and the display control unit 18 controls the display operation of the display device 16.

FIG. 2 is a block diagram showing the configuration of the display control unit 18. As shown in FIG. The display controller 21 controls the display operation based on the display data called as a display target. The gradation level decoder 22 determines the gradation level of the display data, outputs data indicating the gradation levels 1/8, 5/12, etc. according to the result of the determination, and supplies the data to the basic pattern reading unit 23. The frame counter 24, the line counter 25, and the dot counter 26 count the frame count signal, the line count signal, and the dot count signal generated and output from the display controller 21, and the count value of the frame counter 24 is stored in the basic pattern reading unit 23. Given to. The basic pattern reading unit 23 accesses the basic gradation display pattern table 27 based on the decoding result (gradation level) from the gradation level decoder 22 and the frame count value from the frame counter 24 to read the basic gradation display pattern. It is acquired and given to the ON dot decoder 28. The basic gradation display pattern table 27 stores a plurality of types of thinning patterns corresponding to the number of frames corresponding to predetermined basic gradation levels as basic gradation display patterns. A plurality of types of basic tone display patterns read out from the table 27 for each frame unit are given to the ON dot decoder 28. The configuration of the basic gradation display pattern table 27 and the contents of the basic gradation display pattern will be described later in detail. The ON dot decoder 28 thins out new gradations other than the basic gradation by sequentially processing a plurality of types of basic gradation display patterns read from the basic gradation display pattern table 27 in a time series for each frame unit. Generate a pattern. That is, line counter 2
5. A thinning pattern is generated by repeating an operation of determining for each dot unit whether the dot indicated by the count value from the dot counter 26 is turned ON or OFF by referring to the basic gradation display pattern, and the display controller Give to 21.

FIG. 3 shows a basic gradation display pattern table 27.
FIG. 3 is a diagram showing the configuration of FIG. The basic gradation display pattern table 27 stores the basic gradation display patterns corresponding to the basic pattern numbers. In this example, the basic pattern numbers “0”, “1”,. Display patterns "0", "1", "1 / 2A", "1 / 2B", "1 /
"4A", "1 / 4B", "1 / 4C", and "1 / 4D" are associated with each other. Here, “0” is an all dot off pattern indicating that all dots are displayed off, and “1” is an all dot on pattern indicating that all dots are displayed on.
As shown in FIG. 4, the basic gradation display patterns of "1 / 2A" and "1 / 2B" are two types of thinning patterns corresponding to the number of frames corresponding to the basic gradation level 1/2. It is composed of a 2 × 2 minimum matrix pattern. This minimum matrix pattern is a matrix pattern constituting the common pattern element when the thinning pattern for one screen is constituted by repetition of the common pattern element, and when the basic gradation level is "1/2". , A 2 × 2 matrix pattern is stored in the basic gradation display pattern table 27 as a basic gradation display pattern. Similarly, "1 / 4A",
The basic gradation display patterns of “１ ／ B”, “１ ／ C”, and “１ ／ D” have the basic gradation level 1 as shown in FIG.
Four types of thinning patterns corresponding to the number of frames corresponding to / 4, and are constituted by a 4 × 4 minimum matrix pattern.

FIG. 6 shows a read definition information table RDT provided in the basic pattern reading section 23. In the basic pattern reading section 23, a plurality of read definition information tables RDT are provided for each gradation level. ing. Here, (A), (B) and (C) in FIG.
This is an example of the contents of the read definition information tables RDT of 4, 1/8, and 5/12. The basic pattern reading section 23 has various read definition information tables RDT corresponding to other gradation levels. . Read definition information table RDT
Is a configuration in which definition information defining a "basic pattern number" corresponding to a "frame number" is stored for each frame, and the "frame number" of the read definition information table RDT is sequentially accessed by the count value of the frame counter 24. Each time, the basic pattern reading section 23 reads the corresponding basic pattern number, searches the basic gradation display pattern table 27 based on the basic pattern number, sequentially reads the corresponding basic gradation display pattern, and turns it on. This is given to the dot decoder 28. Here, in the case of the gradation level 1/8, if the contents of the read definition information table RDT are the definition information for reading only the pattern of the basic gradation level 1/2 as shown in FIG.
In the frames and the sixth to eighth frames, all dot-off patterns are continuous for three frames,
This may cause "flickering" of the display. Therefore, when the gradation level is 1/8 so that all the dot-off patterns do not continue three times or more, the basic gradation level 1 as shown in FIG. This is the definition content for reading out only the pattern of / 4. In the case of the gradation level 5/12, FIG.
As shown in (C), the basic gradation levels 1/2 and 1 /
4 are defined.

Next, the operation when gradation display control is performed in this data processing device will be described. Now, it is assumed that pattern data is registered in the basic gradation display pattern table 27. Here, when registering the pattern data in the basic gradation display pattern table 27, FIG.
Basic patterns 1 / 2A, 1 / 2B, 1/4 shown in FIG.
A, 1 / 4B, 1 / 4C, 1 / 4D are input and created.
At this time, a black circle in the figure is set as an ON dot, and when this ON dot is designated, “1” is set at the corresponding bit position.
(High level) is set. The basic gradation display pattern thus created is transferred from the CPU 11 to the display control unit 18 and written in the basic gradation display pattern table 27. In this case, it is sufficient to input and create a 2 × 2 or 4 × 4 minimum matrix pattern, and it is possible to create the pattern more efficiently than creating a pattern for one screen. In a state where the pattern thus input and created is registered in the basic gradation display pattern table 27, display target data is called and given to the display controller 21. Then, the gradation level decoder 22 determines the gradation level of the display data, and supplies the decoding result to the basic pattern reading unit 23.

Here, the basic pattern reading section 23 accesses the read definition information table RDT for each gradation level based on the decoding result from the gradation level decoder 22. If the gradation level is 1/4, the read definition information table RDT shown in FIG. 6A is accessed, and the basic pattern number corresponding to the frame number is read based on the count value of the frame counter 24. The basic gradation display pattern table 27 is searched based on the basic pattern number. In this case, if it is the first frame, the basic gradation display pattern 1 / 2A is read out and given to the ON dot decoder 28. Then, the ON dot decoder 28 compares the count values of the line counter 25 and the dot counter 26 with the basic gradation display pattern for each dot unit, and turns the dot ON.
It decides whether to turn off or to turn it off and returns it to the display controller 21 as a thinning pattern. In this case, since the basic gradation display pattern is a 2 × 2 minimum matrix pattern, a thinning pattern for one screen is obtained by repeatedly referring to this minimum pattern. In the second frame, “0” is extracted as the basic pattern number from the read definition information table RDT as shown in FIG. Since all the dots are read out and given to the ON dot decoder 28, all dots are OFF in the second frame.
Becomes Next, in the third frame, since the basic pattern number "3" is extracted from the read definition information table RDT, the basic gradation display pattern 1 / 2B is read from the basic gradation display pattern table 27, and furthermore, In the fourth frame, all dot off patterns are read. Eventually, the sum of the fourth frame is (1/2 × 2) / 4 = 1/4,
For each dot, gradation display control is performed so that ON display is performed once in four frames. In this way, a new pattern of the gradation level １ ／ is generated by the combination of the patterns of the basic gradation level １ ／.

Similarly, the gradation level of the display data is 1/8.
In the case of (1), the basic pattern reading section 23 performs the 1 / 4A pattern in the first frame, the 1 / 4B pattern in the third frame, and the 1 / B pattern in the fifth frame according to the contents of the read definition information table RDT shown in FIG. 4C pattern, 1 / 4D pattern is read out in the seventh frame, and other 2/4
Since all dot on / off patterns are read out at the 6.8th frame, the total of 8 frames is (1/4 × 4) / 8 = 1 /
The gradation display control is performed so that each dot is turned on once every eight frames. Thus, the basic gradation level 1
A new gradation level 1 /
8 patterns are generated. Further, when the gradation level of the display data is 5/12, the basic pattern reading unit 23 reads the basic gradation display pattern for each frame in accordance with the read definition information table RDT shown in FIG. Since the pattern of the basic gradation level １ ／ is read for four frames and the pattern of the basic gradation level ２ is read for four frames, the total of 12 frames is (フ レ ー ム × 4)
+ 1/2 × 8) / 12 = 5/12, and each dot is 1
Gradation display control for performing on display five times in two frames is performed. In this way, a new pattern of the gradation level 5/12 is generated by combining the patterns of the basic gradation levels 1/2 and 1/4.

As described above, in this embodiment, a plurality of types of basic gradation display patterns are read out from the basic gradation display pattern table 27 for each frame based on the gradation level of the display data and the frame count value. Since a new gradation thinning pattern other than the basic gradation is generated by sequentially processing in time series, a plurality of kinds of thinning patterns corresponding to the basic gradation level are stored as the basic gradation display pattern. By simply doing so, a thinning-out pattern of a new gradation other than the basic gradation can be generated. Therefore, the data amount of the basic gradation display pattern table 27 is extremely small, a small-capacity memory is sufficient, and a multi-gradation frame thinning method can be realized without increasing the circuit scale. In this case, the basic gradation display pattern table 27 stores 1 /
Since patterns corresponding to 2, 1/4 are registered,
By combining them, multi-gradation control becomes possible.

Further, the basic pattern reading section 23 refers to the read definition information table RDT and reads the basic gradation display pattern at predetermined timings according to the contents of the definition, so that a circuit for selecting the pattern is simplified. If the contents of the read definition information table RDT are arbitrarily changed, various patterns can be displayed even at the same gradation level. In this case, by defining the insertion of all dot-off patterns and all dot-on patterns in the read definition information table RDT, it is possible to easily realize a multi-tone frame thinning method even if the number of basic gradation display patterns is small. . Here, since the insertion position of the all-dot-off pattern is defined so that the all-dot-off pattern does not continue for a predetermined number of frames, for example, three frames, "flickering" of the display can be prevented. . Further, when the basic gradation display pattern is not data for one screen, but data for one screen is constituted by repetition of a common pattern element, 2 × 2 or 4 × 4 constituting the common pattern element Since this is a dot pattern, the basic gradation display pattern table 27
Memory capacity can be reduced.

In the above-described embodiment, 2
Although the minimum pattern such as × 2, 4 × 4 is further stored in the basic gradation display pattern table 27, a pattern for one screen may be stored. Further, the functions of the gradation level decoder 22, the basic pattern reading unit 23, the frame counter 24, and the ON dot decoder 28 may be realized by program control. That is, a function of determining the gradation level of display data called as a display target, a function of counting the number of frames, and a plurality of types of thinning corresponding to the number of frames corresponding to a predetermined gradation level. A plurality of types of basic tone display patterns are determined from a pattern storage unit that stores the patterns as the basic tone display patterns for each frame unit based on the tone levels of the determined display data and the counted number of frames. Program control of the function to read out at the timing of and the function to obtain a new gradation thinning pattern other than the basic gradation by sequentially processing the read plural kinds of basic gradation display patterns in time series for each frame unit It may be realized by. here,
A program for realizing each function is stored in a storage medium 13 in the form of a readable program code, and the CPU 11 sequentially executes operations according to the program code.

[0018]

According to the present invention, a plurality of types of thinning-out patterns corresponding to the basic tone levels are stored as basic tone display patterns, and new tone thinning-out patterns other than the basic tone are stored. Since the data can be generated, the data amount is extremely small, a small-capacity memory is sufficient, and a multi-gradation frame thinning-out method can be realized without increasing the circuit scale.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a data processing device.

FIG. 2 is a diagram showing a detailed configuration of a display control unit 18 shown in FIG.

FIG. 3 is a diagram showing a configuration of a basic gradation display pattern table 27.

FIG. 4 is a view for explaining a basic gradation display pattern in the case of a basic gradation level of ２.

FIG. 5 is a diagram for explaining a basic gradation display pattern in the case of a basic gradation level of 1/4.

6A and 6B show specific examples of the basic gradation display pattern table 27. FIG. 6A shows a gradation level of 1/4, FIG. 6B shows a gradation level of 1/8, and FIG. 6C shows a gradation level of 5/12. FIG.

FIG. 7 is a diagram exemplifying the contents of a basic gradation display pattern table 27 when all dot-off patterns continue three or more times in a row.

FIG. 8 is a diagram showing the contents of a conventional pattern table memory.

FIG. 9 is a diagram showing a configuration of a conventional display control unit.

[Explanation of symbols]

 Reference Signs List 11 CPU 12 storage device 13 storage medium 14 RAM 16 display device 18 display control unit 21 display controller 22 gradation level decoder 23 basic pattern reading unit 24 frame counter 25 line counter 26 dot counter 27 basic gradation display pattern table 28 ON dot decoder

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H093 NA07 NA55 NA64 NC21 NC50 ND06 ND10 ND49 NF13 5C006 AA01 AA14 AF04 AF13 AF44 AF47 AF53 BB12 BF02 BF14 BF15 BF22 BF26 EC01 FA23 FA44 FA56 5C080 AA05 BB05 DD06 DD22 JJ06

Claims (7)

[Claims] 1. A plurality of types of thinning patterns in which on-display timings indicating which dots in one line are to be displayed on in order to suppress display "flickering" in accordance with a frame thinning method are shifted by the number of frames and the number of lines. A display control device for performing gradation display control using a plurality of thinning patterns corresponding to the number of frames corresponding to a predetermined basic gradation level, as a basic gradation display pattern. Determining means for determining the gray level of display data called as a display target; frame counting means for counting the number of frames; and gray scale level of display data determined by the determining means and the frame counting means. Based on the counted number of frames, a plurality of basic gradation display patterns are stored from the pattern storage means. A pattern readout unit for reading a turn for each frame unit, and a plurality of basic tone display patterns read out by the pattern readout unit are sequentially processed in a time series for each frame unit to thereby obtain a new pattern other than the basic tone. And a pattern generating means for obtaining a thinned-out pattern with a suitable gradation. 2. A pattern reading means, comprising: definition information storage means for storing reading definition information for defining a reading order for reading out the plurality of basic gradation display patterns at a predetermined timing for each of various gradation levels; Is a frame obtained by searching the definition information storage means based on the gradation level of the display data determined by the determination means and referring to a corresponding reading order to obtain a basic gradation display pattern by the frame counting means. 2. The display control device according to claim 1, wherein the data is sequentially read according to the number. 3. The definition information storage means defines read timings of a plurality of types of basic gradation display patterns and defines insertion of all dot-off patterns or insertion of all dot-on patterns between basic gradation display patterns. The display control device according to claim 2, wherein 4. The display control device according to claim 3, wherein an insertion position of said all-dot-off pattern is defined such that said all-dot-off pattern does not continue for a predetermined number of frames. 5. The pattern storage means according to claim 1, wherein when a thinning pattern for one screen is formed by repeating a common pattern element, a matrix pattern constituting said common pattern element is stored as a basic gradation display pattern. The display control device according to claim 1, wherein: 6. When a plurality of kinds of thinning patterns are stored for each of a plurality of kinds of gradation levels in said pattern storage means, said pattern reading means stores the plurality of kinds of thinning patterns corresponding to the plurality of kinds of gradation levels. 6. The display control device according to claim 1, wherein the data is selectively read for each frame unit according to a predetermined order. 7. A recording medium having a program code read by a computer, comprising: a function of determining a gradation level of display data called as a display target; a function of counting the number of frames; A plurality of types of basic gradation display patterns are stored as a basic gradation display pattern by storing a plurality of types of thinning patterns corresponding to the number of frames corresponding to the tone levels. A function of reading out at a predetermined timing for each frame unit based on a tone level and the counted number of frames, and sequentially processing a plurality of kinds of read basic tone display patterns in a time series for each frame unit. Having a program code for realizing the function of obtaining a new gradation thinning pattern other than the basic gradation Medium.