JPS6250818A - Lcd display device - Google Patents

Abstract

PURPOSE:To simplify constitution and reduce its cost by dividing an LCD panel into two and connecting X-dot electrodes to each other in parallel, and driving them by a common driver and cascading and driving Y electrodes. CONSTITUTION:The panel is divided into two LCDs 2A and 2B, whose X electrodes are connected in parallel to the common X driver 6. The Y electrodes of the LCDs 2A and 2B are connected to a Y driver 7 so that a serial scan from the LCD 2A to the LCD 2B is possible; when a signal is inputted from a control system to the X driver 6, a shift register makes a shift successively and the result is latched in the X driver 6 when a shift is made by a half as many as the number of lateral dots, thereby driving the X electrodes of the LCDs 2A and 2B at the same time. The Y electrodes of the LCDs 2A and 2B are driven in series with the output of the Y driver 7, so the number of drivers of an LDC device wherein the number of Y dots is <=1/2 as large as the number of X dots is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an LCD display device used, for example, in a character display section of a document creation device.

[Technical background of the invention and its problems]

A conventional driving means for an LCD (liquid crystal) display device used in a document production device or the like will be explained with reference to FIGS. 1 and 5 to 1. Fig. 1 is a horizontal diagram showing the circuit configuration of an LCD display device and its surroundings, and the part within the broken line is the part targeted by the present invention. Fig. 5 shows the conventional structure within the broken line in Fig. 1 above. This is a circuit diagram showing the circuit configuration of the -LCD display device. Fig. 6 shows its specific operation timing diagram, and Fig. 7 also shows the relationship between the screen display position and the LCD-RAM address. It is a diagram.

Here, the LCD 2 shown in FIG. 5 is composed of m width and nY height, and as a specific example, here, the LCD 2 is 240P.
, n=321'y). The LCD control LSI (LCDC) 5 shown in Fig. 1 is a display memory (LCDC).
D.RAM) 4 is converted into serial data and input to the X driver 6... The data input to this Xr driver 46... is the shift clock for the X driver (S
CP) synchronize with the shift register in p lie/9 and use XP dry 4 at the end of the shift of m do, g. Output.

In the Y dry defense, the electrodes of the n lines are connected in parallel line by line, and the l to n lines are sequentially shifted and r-typed by the shift clock (hp) for the Y dry defense. As described above, the mXn dot LCD 2 is driven by m X drivers 6 . . . and n Y drivers 47 . . . to perform display. At this time, the display operation timing is as shown in Figure 6, and the display position and display memo IJ (L
The relationship between CD@RAM) addresses is shown in FIG. In addition, CDATA is a synchronization signal for YP Rai/4,
PR is a frame signal.

However, the driving means in the above-mentioned conventional LCD display device continuously drives the horizontal dots and dots of the LCD at a constant timing. , the number of drive output points (240 points in the above example) corresponding to the number of X-drivers is required, and therefore there is a problem that a large number of X-drivers are required. It is an object of the present invention to provide an LCD display device which can simplify the configuration and reduce the cost by reducing the number of LCD display drivers.

[Summary of the invention]

The present invention divides an LCD panel with a predetermined dot matrix configuration into left and right halves, connects the corresponding X electrodes on the left and right sides in parallel, and drives the parallel connected X electrodes with a common driver. , the Y electrodes of the left and right I, CD/buttons are driven in tandem on the left and right in line units, so that the number of YP and G is 1/2 of the number of X- and G. In a small LCD display device, the number of drivers can be reduced, and the configuration can be simplified and the cost can be reduced.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram showing an LCD display device and its peripheral circuit configuration according to the present invention.

In the figure, 1 is a processing unit (hereinafter referred to as C) that controls the entire system.
9.LCD control LSI (referred to as PU).
By connecting an LCDC, it is possible to perform display control from the same CPU J. 2 is a liquid crystal display element (hereinafter referred to as LCD) that visually outputs information. 3 is a character ROM (hereinafter referred to as CGROM) that stores the fonts of characters displayed on this device.
It is. 4 is a display memory (
(hereinafter referred to as LCD-RAM), and corresponds to V-RAM in a CRT display. 5 is an LCD control LSI that controls the display of LCD 2 (TL
(referred to as CDC). Drivers 6 and 7 convert display serial data from the LCD into parallel data and drive the LCD.

FIG. 2 is a Zoroku diagram showing an embodiment of the present invention in the LCD display section shown by broken lines in FIG. 1. Here, assuming the matrix configuration of the LCDJ1mXnPy shown in FIG. 1 above, it is divided into two symmetrical panels of ry'2
, the other is LCD 2 B, and these LCD j
The corresponding X electrodes of A and 2 B are connected in parallel.

And the two X connected in parallel of the above LCDjA and JR
The connection configuration is such that the electrodes are each driven by a common r/4c (hereinafter referred to as an x driver) 6. Also, LCD l
The Y electrodes of A and 2B are supplied with separate drive signals for each line by a driver (hereinafter referred to as Y driver) 2 so that line scanning of -LCD j H is performed subsequent to line scanning of LCDJA. The structure is as follows.

FIG. 3 shows the operation timing of the above embodiment, and FIG. 4 shows the LCD display position and the LCD display position in the embodiment.
- A monomer indicating the relationship with the RAM address, here L
The number of dots in the X (horizontal) direction of CD2 (LCD2AILcD2B) is 2401'y, and the number of dots in the Y (vertical) direction is 32r.
), the home address is @Q QH%, and the number of area digits is @10. ”.

That is, here, the LCD 2 is a bilaterally symmetrical LCD 2 A having an XY-120X32 dot matrix.

LCDJA n line scanning (Y1 to Y
! When step 1) is completed, n-line scanning (Yn+1 to Y2n) of the LCD 2B is subsequently performed.

Here, the operation of one embodiment will be explained with reference to FIGS. 1 to 4.

Figure 1: cGROM s CPU J
Display stored in LCD-RAM 4 via f)J
? After the turn information is converted to serial data by the LCD 5, it is input to the X-Dry/96 shown in Figure 2, and the
The shift register in dry/f is sequentially shifted using the driver shift clock (cscp), and when the shift of rrv/2 do, g is completed, the
Latched by livero, 2 people on LCD.

Two BOX electric charges are driven at the same time. On the other hand, LCD2A,
The Y side electrode of 2B is connected to the Y) 1~n line outputs of the Y) life puff are connected to the Y electrode of the LCD 2A, and the n+1~2n line outputs are connected to the LCD 2B f) Y electrode jc7.
Shift clock (LP) Ic for Y17 Rai/4, L
CD2A Y electrode line Y1~Yns LCDjB
The Y electrode lines Yn+1 to Y2n are sequentially driven in this order.

By repeating the above operations, information is displayed on the LCDJ. In addition, CDATA in the figure is the synchronization signal for Ygeliper,
[8 indicates a frame signal.

Through this better LCD drive control, the number of y-lighter displays can be reduced. That is, for example, each of the drivers 6 and 7 has an I chip with 916 drive output points per l chip.
C, and as above, the LCD
22>EX= 2401't, P of Yx32pt
The conventional configuration shown in FIG. 5 requires a total of 17 chips, including 15 chips for the X driver/f #1c and 2,000 chips for the Y driver 7, but In the configuration of one embodiment shown in FIG.
8 chips in 6, 4 chips in Y driver 7, f total 12 chips,
f, and it becomes possible to drive a -P driver LCD, which requires fewer -P drivers than in the past.

〔Effect of the invention〕

As detailed above, according to the LCD display device of the present invention,
The LCD I4 channel with a predetermined dot matrix configuration is divided into left and right halves, and the corresponding X electrodes and G electrodes on the left and right sides are connected in parallel, respectively, and the parallel connected X electrodes are driven by a common driver. -The Y electrodes of each channel are arranged in rows on the left and right for each line to drive the LCD.
In the display device, the number of drivers can be reduced, and the configuration can be simplified and the cost can be reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a Zoroku diagram showing the structure of an LCD display device and its surroundings, which is the object of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. A diagram showing the operation timing of the embodiment, FIG. 4 is a diagram showing the screen display position and display memory (LVCD-RAM) 7 Yv:x(D relationship in the above embodiment, and FIG. 5 is a diagram of the conventional LCD display device. 6 is a block diagram showing the operation timing of FIG. 5 above, and FIG. 7 is a block diagram showing the screen display position and display memo IJ (LVCD-RAM) address according to the device configuration of FIG. 5 above. It is a diagram showing the relationship. 2, 2B...Liquid crystal display element (LCD), 6, 6.
Roe-(PI

Claims (1)

[Claims] An LCD panel that is divided into left and right halves and has corresponding X-dot electrodes on the left and right connected in parallel, an X driver that commonly drives the corresponding X-dot electrodes on the left and right of this LCD panel, and an An LCD display device comprising: a Y driver that sequentially drives Y electrodes in columns line by line.