JPS63287828A - Liquid crystal display controller - Google Patents

Abstract

PURPOSE:To eliminate drop-out of display data and to enable exact reading of a display by executing a gradation display by a flickering display at the respective dots of a liquid crystal by shifting gradation pattern signals at every frame period and executing an area modulation display over the entire part of an image plane. CONSTITUTION:A memory control part (memory control means) 1 forms memory control signals 4 and memory address signals 5 by using the timing signal 3 sent from a timing forming part 2 and reads the display data 12 successively from a display memory 6 in which the display patterns are stored. On the other hand, said control part forms a liquid crystal control signal 8 from the timing signal 3 sent from the timing forming part 2. A gradation pattern forming part 9 forms a gradation pattern signal (area modulation signal) 10 by the liquid crystal control signal 8. A gradation selecting part 11 selects gradation display data 15 from the gradation pattern signal 10 is compliance with the value of the display data (display information) read out of the display memory 6. The gradation display which eliminates the drop-out of the display and decreases flickering is thereby enabled and the excellent functions are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display control device that performs gradation display of a liquid crystal display length [(hereinafter abbreviated as LCD).

[Conventional technology]

Conventionally, the following methods have been used to display floor vL4 on an LCD.

First of all, as an example, the Japanese Patent Application Publication No. 58-57192
There is one that uses a blinking display as described in the @ gazette.

As shown in Figure 7, this is displayed every time according to the frame period (vertical period) ((α) in the same figure), and 2 times every 3 times.
The visual display can be improved by blinking the display twice ((b) in the same figure) or once every two times ((C) in the same figure). , This is a method that takes advantage of the fact that the image appears to have a difference in shading (gradation), as shown in the bottom row of (c).

Another method is to use area modulation display.

This corresponds to the density of the black display area as shown in Figure 8 by taking advantage of the fact that due to the difference in the density of the black display area that occupies the display area, there is a visual gradation difference (C gradation). This is a method of displaying gradations using a display pattern (however, the coordinates of the black portion are fixed). Same figure (α)
are 1/1 and 2/3 of the total pixels that make up the display area *
By driving 1/2, light and shade is displayed, and in the same figure (b), by driving 1/112/3, 172 of the pixels for letter A, the letter A with #light is displayed. It shows.

[Problem that the invention attempts to solve]

The above conventional technology has the following problems.

First, the blinking display method uses large LCDs (640 dots x 200 dots, 640 x 400 dots, etc.) that are currently in use, and the Q-frame period is usually about 60 to 80 Hz. Therefore, the blinking cycle in the case shown in CC) of Fig. 7 is 30H.
z~aoHz, the blinking cycle in the case shown in (b) of the same figure is as low as 20Hz~2711z, so even considering the response speed of the LCD, it is possible to recognize the blinking of the display, and this is the flickering of the display. There was a problem that it appeared as a flicker.

It also uses area modulation display. In the method, the above-mentioned FIG. 8Cb
), when trying to display details such as character patterns, part or all of the character pattern 7, etc. is missing, so it cannot be displayed correctly as shown in the middle row of the same figure. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display control device TIL that has less flickering in the display and can display gradation without any trouble even in the case of a sharp display such as a character pattern.

[Means for solving problems]

The above purpose is to display data using a data transfer clock (hereinafter referred to as shift clock) and a horizontal periodic signal (hereinafter referred to as line clock) of the liquid crystal control value g (hereinafter referred to as LCD control signal). = Multiple V@ corresponding to K (gradation)
A means (gradation pattern generation unit) is provided for generating tone pattern individual numbers and shifting each tone pattern signal for each frame period, and area modulation display is performed using the shifted tone pattern signals. It is achieved by doing.

However, the way the gradation pattern signal is shifted is that in one gradation, no matter which dot (pixel) on the entire screen is targeted, it blinks with the same period and waveform, only the phase of the blinking differs.

[Effect]

In the present invention, by shifting the gradation pattern signal every frame period, when focusing on each dot on the LCD, a gradation display is performed by blinking display, and when focusing on the entire screen, an area modulation display is performed. Become.

Therefore, even in a detailed display such as a character pattern, there is no omission of displayed data, so the display can be read accurately.

In addition, the dots that blink in the same phase are evenly distributed over the entire screen and are dispersed to some extent, and furthermore, the dots that touch each other have a visual influence on each other. The screen flickering caused by each flash is reduced.

〔Example〕

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

FIG. 1 is a block diagram showing one embodiment of a liquid crystal display control device according to the present invention, in which 1 is a memory control section, 2 is a timing generation section, 3 is a timing signal, 4 is a memory control number 15,
5 is a memory address signal, 6 is a display memory, 7 is an LCD
a control section; 8, an LCD control signal; 9. 1 is a gradation pattern generation section, 10 is a gradation pattern signal, 11 is a gradation selection section,
12 is display data, 13 is a timing control unit, 14 is L
CD display data, 15 is gradation display data.

In the same figure, using a timing signal 3 sent from a timing generation section 2, a memory control section (storage control means) 1 generates a memory control 4a number 4 and a memory address signal 5, and stores a display pattern. The display data 12 is sequentially read from the display memory 6.

On the other hand, from the timing signal 3 sent from the timing generation section 2, the LCD control s7 generates an LCD control signal 8 that controls the timing of display on the LCD.

The gradation pattern generation section 9 generates a gradation pattern signal (area modulation signal) 10 based on the LCD control signal 8 .

The floor A selection unit 11 generates a gradation pattern signal 10 corresponding to the value of display data (display information) read out from the display memory 6.
Select gradation display data 15 from .

Furthermore, the timing control unit 13 converts the grayscale display data into the LC.
The LCD according to the display timing is controlled by the D control signal 8.
Send display data.

The embodiment shown in FIG. 1 realizes gradation display in a method generally called a graphic method.
Here, color display data is converted into gradation display data and displayed.

This is done by using the gradation tracing section 13 to select the gradation display data 15 corresponding to the color represented by the value of the color display data 12 read out from the display memory 6 out of the gradation pattern signal 1o.
The display is sent out in accordance with the display timing.

It should be noted that FIG. 1 only shows the display output system, and since the portions such as loading data into the display memory 6 are not the main point of the present invention, their explanation will be omitted.

Next, an example of the operation of the gradation pattern generation section 9, which is a feature of the present invention, will be explained using FIGS. 1 to 5.

Fig. 2 is a diagram showing a part of the screen when the entire screen is displayed in one gradation, and the figure (α) is a black display density of 1/1.
The display pattern in the same figure (, 6) is the display pattern with black display density 2/3, and the same figure (C) is the display pattern with black display @ degree 1/! This is the display pattern.

In the present invention, the gradation pattern (area modulation display pattern) is generated at each frame period [1 to 4] by the gradation pattern generation unit 9 in FIG. While performing gradation display, each dot is displayed in gradation by blinking.

The method of shifting the area modulation display pattern is shown in Figure 2 (α
) to (C), no matter which dot you focus on within the same gradation, the blinking period and waveform are the same, only the phase is different.7. need to be met.

FIG. 3 is a timing diagram showing an example of a gradation pattern signal corresponding to the display pattern shown in FIG. 2, and (α), (b), and (C) in FIG. α)
, Cb) and (C), respectively.

In the same figure, DoyD indicates the drive signal waveform, and the first
This is an example in which the data width is 4 as the gradation pattern signal 10 in the figure.

FIG. 4 is a timing diagram illustrating how the gradation pattern signal corresponding to the display pattern shown in FIG. To shift, one screen display period (frame period or vertical period) or a signal corresponding to this can be used.

Next, detailed display of character patterns and the like according to the present invention will be explained for row 516.

FIG. 5 is a diagram showing a part of the screen for explaining a case where a character pattern (letter A) is displayed in the gradation display pattern shown in FIG.

According to the invention, the conventional surface shown in FIG.
・Unlike the method using product modulation display, as shown in Figure 5,
Each dot forming a character is always illuminated at a certain period, so there are no omissions in the display.

Furthermore, unlike the conventional blinking method shown in FIG. 7, the display does not disappear for the entire period of one frame (the dots forming the letters are illuminated regularly and in an appropriate manner).

Therefore, adjacent dots exert a visual effect on each other, reducing display flicker.

FIG. 6 is a configuration diagram showing another embodiment of the present invention, 1
6 is a display code, 17 is attribute data, 18 is a floor-mask pattern signal, 19 is a data mask section, 20 is a display code memory, 21 is an attribute memory, and 22 is a display pattern generator, and the same reference numerals as in FIG. Corresponds to the same functional parts.

In the same figure, using the timing signal 3 sent from the timing generator 2, the memory 1 is a display code memory 20 that stores display codes and an attribute memory that stores attribute data that modifies each display code. A memory control signal 4 and a memory address signal 5 are generated in order to sequentially read out the display code 16 and attribute data 17 from 21.

Furthermore, the gradation selector 11 selects a gradation mask pattern signal 18 corresponding to the value of the attribute data 17 read from the attribute memory 21 from among the gradation pattern signals 1o.

Furthermore, the data mask section 19 generates a display pattern s2.
In step 2, the display data 12, which is the actual display pattern converted from the display code 16, is modified in gradation with the gradation mask pattern signal 18.

The example shown in FIG. 6 is to realize the display of floor B14 in a method generally called the CG (Character Generator) method.The attribute data 17 has modification information regarding the gradation, and the display data is converted into the attribute data. The display is modified using the gradation indicated by . Finally, the modification is realized by masking the display data 12 with the gradation mask pattern signal 18 indicated by the value of the attribute data 17.

In the actual mis shown in FIG. 6, the operating principle of the gradation pattern generation section 9 may be the same as that of the embodiment shown in FIG. 1, and the gradation display is the same as that shown in FIGS. It can be performed.

Therefore, in the embodiment shown in FIG. 6 as well, gradation display with no display missing and less flickering can be realized.

〔Effect of the invention〕

As described above, according to the present invention, a gradation display with no display missing and less flickering can be realized in a liquid crystal display device, and an excellent a-performance liquid crystal display control device can be obtained by eliminating the drawbacks of the above-mentioned conventional technology. can be provided.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing an embodiment of the present invention, Figure 2 is a diagram showing a part of the screen when the entire screen is displayed in one gradation, and Figure 3 is a diagram showing the display pattern of Figure 2. A timing diagram showing an example of a corresponding gradation pattern signal, a timing diagram illustrating how to shift the frame circumference M of a gradation pattern signal whose fourth factor corresponds to the display pattern shown in FIG. Figure 5 shows a part of the screen to explain the case where the character pattern is shown in the gradation display pattern shown in Figure 2.
FIG. 7 is a block diagram showing another embodiment of the present invention, FIG. 7 is a diagram showing the principle of gradation display using conventional blinking, and FIG. 8 is a diagram showing an example of gradation display using the area modulation method. 1... Memory control s 2... Timing generation section 3
...Timing signal 4...Memory control signal 5...
・Memory address signal 6...Display memory 7...LC
D control unit 8... LCD control signal 9... Gradation pattern generation 910... Gradation pattern 11... Gradation selection s 12... Display data 15... Timing control s 14... LCD display data 15...Gradation display data 16...Display code 17...Attribute data 18...Gradation mask pattern signal 19...Data mask section 12 ・Figure 2 (Q) ) Impatience Songan and Kuro Gokyo, 2 Fukyu Oken Sekyu X Demon 3
(2) Jl 4 Atsushi 5 Figure -7 (Q) (b) (c) Abusive 8
Figure (α) (shi)

Claims (1)

[Claims] 1. Storage means for storing display information such as characters and figures; storage control means for reading out the display information from the storage means; and timing control means for sending the display information read from the storage means to a liquid crystal display device. , a liquid crystal display control device comprising a liquid crystal control means for controlling the display of the liquid crystal display device, wherein a liquid crystal control signal from the liquid crystal control means is used to adjust the black display portion on the liquid crystal display device according to the display density. A gradation pattern generating means is provided for generating one or more gradation pattern signals defining density, and shifting the gradation pattern signal every one screen display period, and the shifted gradation pattern signal is read out from the gradation pattern signal. By selecting and displaying the displayed information according to the value of the displayed information, or by masking and displaying the read display information using a gradation mask pattern signal selected from the shifted gradation pattern signal, the gradation with less flickering can be achieved. A liquid crystal display control device characterized in that it is configured to perform display.