KR810001643B1 - Character indicator for liquid crystal - Google Patents

Abstract

This invention is related to the display device for HANGEUL, the korean character, in a combined letter type, chinese character, etc. The liquid crystal display device in dotmatrix type comprises segment scanning decoder(3) to which the display panel is connected, RAM(2) supplying the display panel with character information, computer system(4) and keyboard(5).

Description

LCD Display Device for Small Character Display

1 is an external view of a small portable Korean display device of the present invention.

2 is a view illustrating a conventional digit scanning display device.

2 is a connection diagram of a conventional segment scanning display apparatus.

3 is a schematic diagram of a keyboard scanning system of a display according to the present invention;

FIG. 3b is a timing diagram of the device of FIG.

3 is a graphic signal of a character stored in RAM.

3 is a configuration diagram and waveform diagram of a driving circuit of a liquid crystal plate.

4 is a schematic diagram of a telephone number storage device using the principles of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small liquid crystal display device that can display Korean characters, Chinese characters, or other characters. The present invention relates to a liquid crystal display device for displaying Korean characters and collecting other characters, such as Chinese characters, from a portable or desktop electronic device.

Conventionally, the small display device used is a display device using an LED, a liquid crystal display device, etc., but this is a display device for displaying only numbers or English letters, and it is very difficult to use it as a display device in Korean.

For example, in the case of Hangul, one collected Hangul letters must be larger than the size of English or numbers, so more display elements are required.

For English or numbers, 7-segment display method may be used, and in the case of DOR matrix method, 5 × 7 is enough to display one letter, but at least 10 × 13 is required for Korean. Done.

Therefore, there are many difficulties in displaying Korean characters in a conventional small display device.

Another problem for displaying Korean characters is as follows.

In other words, it is difficult to make the duty cycle less than 1/7 with the current liquid crystal display technology (in which case, the displayed characters are not clear) (DUTY CYCLE) becomes less than 1/7, and Hangul cannot be displayed properly.

In the case of Chinese characters, the above reason cannot be displayed clearly.

Disclosure of Invention An object of the present invention is to provide a liquid crystal display device having a duty cycle of 1/7 or more but capable of displaying Korean and Chinese characters clearly.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a typical Hangul phone number storage device composed of a plastic case 1, a keyboard 2, and a display 3 to which the present invention can be applied.

The keyboard consists of number keys (0-9), letter keys (aA, bB, cC, dD, etc.) and function keys (Korean, English, memory, playback), and the display has a 10 × 14 dot matrix. A liquid crystal display panel is used.

Previously, for products that can only display numbers or a few simple characters, such as calculators, 7-segment LED display tubes are used for digit scanning.The wiring is shown in Fig. 2 (a). same.

In brief, this method turns on and off the seven segments to display the desired number, and all segments of the same position of all letters are connected to the same terminal.

When voltage is applied to the cathode (common electrode) of each letter, the corresponding segment is turned on, so it appears alternately one by one from the left and appears repeatedly at high speed.

This method adopts low-cost 7-segment LED display, so it can display complex letters such as Hangul or Chinese characters, and if the number of characters is large, the duty cycle will be less than 1/7. There is a flaw that cannot be.

In addition, the dot matrix display employed in a portable product capable of displaying English characters performs segment scanning, and a calculator circuit composed of this segment scanning principle is shown in FIG.

This method consists of a dot element where each digit is arranged in 5 × 7, all letters (or numbers) are turned on at the same time, the top line is turned on next, and the second line is turned on. It is a way to repeat.

This method is very suitable for LED devices, but because of the high power consumption, it can be put into practical use in portable small electronic devices and LCD devices that cannot shorten the duty cycle cannot display more than seven lines with current technology.

It takes at least 13 lines to display Hangul and more lines to display Hanja, so you can't make a display panel that can display Hangul or Hanja in this way.

Also, Hangul is not the same shape when it is input with the key and when it is displayed on the display. That is, when entering the school, you should enter like ㅛ ＂ㅎ ㅏ, ㄱ, ㄱ ㅛ＂. However, when displayed, it is displayed as a collation, such as "school", the apparatus of the present invention should include a collation process that was not present in the conventional calculator or English letter product.

In the present invention, the CPU processes the write-in process by the program.

FIG. 3A is a system diagram of the present invention, where 1 is a display panel in which liquid crystal display elements are arranged in a dot matrix form, and 2 is a random access memory (RAM) for supplying character information to the display panel. (3) is a segment scanning decoder for supplying a signal for scanning a display panel segment, (4) is a computer system including a CPU and ROM RAM, and (5) is a keyboard.

Computer system. The built-in CPU collects the characters to be displayed and combines them according to the writing program, and stores the graphic signals in the display RAM 2, and converts the Chinese characters and other characters into graphic signals and stores them in the RAM 2 as well.

It also supplies segment information to the segment scanning decoder 8 so that this information can be decoded to scan the keyboard and display panel. A device for collecting and writing Korean character information input from a keyboard is described in detail in Korean Patent Publication No. 80-276.

Referring to the wiring of FIG. 3 (a), the line of information from the segment scanning decoder 3 is connected to a dot display device corresponding to two or more rows per line, and the RAM 2 storing display information. The output lines from are connected to the arcs divided into several of the dot display devices. According to such a configuration, as shown in the timing diagram of FIG. 3 (b), seven segment scanning decoder outputs are maintained to maintain a duty cycle of 1/7, and the graphic output information is divided into several pieces in the RAM 2 in which display information is stored. By properly supplying each part, it is possible to display Hangul kanji and other characters.

The graphic signal of the characters stored in the RAM as described above is shown in FIG.

In other words, when a Hangul character called “Ga” is stored, the upper half of information is sequentially outputted to odd-numbered data lines, and the lower half of information is sequentially outputted to even-numbered data lines. Korean characters can be displayed without reducing the duty cycle.

At this time, the RAM 2 must simultaneously output BIT corresponding to the number of divided driving parts × number of dots in one line of display elements in one line of the display panel, and this output should be continued until the next command. It includes. For example, if a 10 × 14 dot matrix is used for a liquid crystal display and two division driving is performed, it should be output when 2 × 10 = 20BIT operation.

Since the CPU cannot process all these bits at the same time, after one line is displayed, the graphic signal corresponding to the next line is created and stored in the RAM (2) in order and displayed at once.

Therefore, the RAM 2 is not a ROM (Read Only Memory) normally used for dot matrix driving, but a display RAM having a display latch, and the capacity of the latch is the number of divided driving portions x the number of dots BIT per line. In addition, if a liquid crystal display device operated with a small duty cycle is developed due to the technical innovation of the liquid crystal display device, a display device capable of displaying more character information by modifying a program with the same electronic circuit may be developed.

FIG. 3 (d) shows a circuit configuration and waveforms for the driving capacity to be displayed, and the liquid crystal panel is driven at an AC voltage of 20H ₃ -10KH ₃ , eliminating the shortening of the lifetime by electrolysis.

This AC voltage is not shown in FIG.

That is, an alternating voltage as shown in FIG. 3 (d) is equally applied to the liquid crystal plate.

4 is a schematic diagram of a telephone number storage device that stores a number and an owner name of a frequently dialed phone and can easily remember it.

(1) is CPU, 2 is ROM with built-in program, (3) is RAM (RAM1) for storing phone numbers, (4) is keyboard, (5) is segment scanning decoder, and (6) is display RAM (RAM2), and (7) is a liquid crystal plate.

CPU1 determines the input from Keyboard 4 and stores it in RAM3 according to the program recorded in ROM 2.

The CPU 1 again stores the stored signals in the display RAM 6 in combination according to a known write-out program recorded in the ROM 2.

On the other hand, the CPU 1 sends the segment information to the segment scanning decoder so that the Hangul can be displayed on the display panel 7.

The present invention is to be used as a portable by minimizing the power consumption by allowing the LCD panel to use the character display device of the small electronic device as described above.

Claims (1)

Keyboard and CPU of well-known small portable electronic device. RAM. In the dot matrix liquid crystal display panel having ROM, segment scanning decoder and more than 13 lines The liquid crystal display panel 1 is divided into two columns of seven rows, and the order of each row is connected in parallel to connect to the output of the segment scanning decoder 3, and each column is connected to the output of the RAM 2, so that the duty cycle is 1/7. A liquid crystal display device for small character display, which drives a liquid crystal display plate as follows.

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