JP3210195B2 - Display control device for liquid crystal display system - Google Patents

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 a liquid crystal display system, and more particularly, to a liquid crystal display device having a different number of display dots connected to a computer or the like in a replaceable manner. The present invention relates to a display control device of a computer system using the computer as a display monitor of a main body of the computer or the like. For example, in a device such as a computer designed in consideration of a plurality of products, the present invention is applied to display control of a computer system that can operate with the same control program even when the number of dots of display is different. .

[0002]

2. Description of the Related Art A display device and a computer main body can be separated from each other.
In JP-A-110492, means for setting output timing using an identification signal is used.

FIGS. 7A to 7E are configuration diagrams of a conventional liquid crystal display system, in which 11 is a computer main body, and 12a and 12a.
12b is a liquid crystal display device, 13a is a main body side connector, 13
b is a display device side connector, 14 is a liquid crystal display, 1
5 is an operation key.

The computer main body 11 and the liquid crystal display devices 12a, 1
As shown in FIG. 7 (a), a connector 13a is provided on the computer main body 11, and the liquid crystal display devices 12a and 12b are connected to the liquid crystal display devices 12a and 12b as shown in FIGS. 7 (b) and 7 (c). Are provided with connectors 13b, respectively. The connectors 13a and 13b have, in addition to display data terminals for outputting display data from the computer body 11 to the liquid crystal display devices 12a and 12b, one of the liquid crystal display devices 12a and 12b.
An identification signal terminal for providing an identification signal for identifying the number of horizontal line pixels from the liquid crystal display devices 12a and 12b to the computer main body 11 is provided.

More specifically, as shown in FIGS. 7 (d) and 7 (e), a plurality of types of liquid crystal display devices such as a liquid crystal display device 12a (dot number m) and a liquid crystal display device 12b (dot n) are attached to and detached from the computer main body 11. By connecting the main body side connector 13a and the display device side connector 13b, the identification signals in both connectors are connected, and the computer main body 11 is connected to the liquid crystal display device 12a.
The number of dots a and 12b can be detected.

FIG. 8 is a diagram showing a conventional example for setting the output timing of display data. In the figure, reference numeral 20 denotes a display controller, 21a and 21b denote oscillators, and other parts which operate in the same manner as in FIG. Are given the same reference numerals.

The liquid crystal display 12a has a number m of dots (horizontal lines), and the liquid crystal display 12b has a number n of dots.
(Horizontal line). The identification terminal T1 of the liquid crystal display device 12a is grounded via a resistor R1. On the other hand, the identification terminal T2 of the liquid crystal display device 12b is connected to the power supply line VCC via the resistor R2. The display controller 20 in the computer main body 11 is connected to be able to switch between the oscillators 21a and 21b. The oscillator 21a outputs a basic clock pulse of the liquid crystal display device 12a having a display of one horizontal line dot number m, and the oscillator 21b outputs a basic clock pulse of the liquid crystal display device 12b having a display of one horizontal line dot number n. Output.

When a ground level identification signal is input to the identification terminal, the display controller 20 detects that one horizontal line dot number of the liquid crystal display device 12a connected to the computer main body 11 is m. Is switched to the oscillator 21a based on this. Similarly, when the identification signal of the power supply level is inputted, it is detected that the number of dots of one horizontal line of the liquid crystal display device 12b is n, and the switching to the oscillator 21b is performed based on this.

Thus, the display controller 20 sets the timing suitable for the display of the connected liquid crystal display device based on the oscillation output of each of the oscillators 21a and 21b.
By outputting the display data in accordance with this timing, correct data display is performed on each pixel of the liquid crystal display 14 of the liquid crystal display devices 12a and 12b.

[0010]

As described above, in a conventional display control device of a liquid crystal display system, display control can be performed according to a liquid crystal display device having a different number of dots. Only a few liquid crystal displays can be connected. In other words, it is possible to detect and set the liquid crystal display device to the power of 2 as the number of the identification terminals, but it is not possible to cope with a liquid crystal display device with more than that and other than the setting. Therefore, it was necessary to increase the number of identification terminals in order to increase the types of liquid crystal display devices.

The present invention has been made in view of such circumstances, and does not increase the number of identification terminals and does not attach a special circuit as in the conventional example (in the conventional example, only one resistor is used). It is an object of the present invention to provide a display control device of a liquid crystal display system which detects the number of dots of a liquid crystal display device.

[0012]

According to the present invention, there is provided a liquid crystal display comprising: a plurality of liquid crystal displays having different numbers of display pixels;
In an electronic device that can be used by attaching and detaching the display part and adopting a simple matrix system as a liquid crystal display system, a data shift clock is used for a liquid crystal display driver using a cascade connection signal of a liquid crystal driving driver. Department
Given to the minute of the segment driver, a first monitor means for monitoring a cascade signal from the final element of the segment driver while counting the number of said clock pulses, the data bits to the number of clocks when the cascade signal is output The first to detect the number of horizontal dots by multiplying the number
And a line shift pulse to the mounted liquid.
Given to the common driver of crystal display portion, a second monitor means for monitoring a cascade signal from the final element of the common driver while counting the number of said clock pulses, the number of clocks when the cascade signal is output have a second detecting means for detecting that the number of dots vertically
And the number of horizontal dots detected by the first detecting means.
And the number of vertical dots detected by the second detection means
Drive control of the mounted liquid crystal display part according to
It is characterized by having done so.

[0013]

The display control device of the liquid crystal display system according to the present invention having the above-mentioned configuration pays attention to the operation of the liquid crystal driver in the liquid crystal display device and the signals used, and utilizes the normal operation signal of the liquid crystal driver. Solved. Using the cascade connection signal of the liquid crystal drive driver, apply a data shift clock to the segment driver, monitor the cascade signal from the last element of the segment driver while counting the number of clock pulses, and when the signal is output The number of horizontal dots is detected by multiplying the number of clocks by the number of data bits, and a line shift pulse is applied to the common driver.The cascade signal from the last element of the common driver is counted while counting the number of clock pulses. The number of clocks at the time when the signal is output is detected as a vertical dot number (pixel number).

[0014]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a display control device of a liquid crystal display system according to the present invention.
Is an LCD (Liquid Crystal Display) panel, 2a
2c is a segment driver, 3a to 3b are common drivers, and 4 is a connector.

The last stage EIO 2 of the segment drivers 2a to 2c and the last stage DI of the common drivers 3a and 3b
It is designed to connect O2 to the main body. The display controller of the main body outputs DIO1, EIO1, LP, and XCK in the following procedure in order to detect the number of dots before displaying. XCK is a data shift clock,
This is a clock for taking display data into the segment drivers 2a to 2c.

LP is a line shift pulse, which is used for generating a selection pulse for the common drivers 3a and 3b and for clearing the segment drivers 2a to 2c (starting data fetch for one line). DIO1 is a start signal of one screen of the common drivers 3a and 3b. The selection pulse width of one line is from the fall of LP after the signal becomes "H" to the fall of LP. Also, 2
The common drivers 3a and 3b in the subsequent stages are connected to the DIOs in the preceding stage.
2 and used as a cascade signal.

DIO2 is used for cascade connection of the common drivers 3a and 3b, is connected to the next stage DIO1, and is taken into the next stage when LP falls. In the embodiment of the present invention, DIO2 at the last stage is used for detecting the number of vertical dots. The EIO1 is fetched at the start of the one-line fetch of the segment drivers 2a to 2c (fall of LP), and is used to shift and fetch data. In the second and subsequent stages, an EIO2 indicating that the data acquisition of the preceding stage has been completed is connected and used to know the timing of data acquisition.

The EIO 2 has segment drivers 2a to 2
c for cascade connection, connected to the next stage EIO1, X
Captured at the falling edge of CK. In the embodiment of the present invention, EIO2 at the last stage is used for detecting the number of horizontal dots. M is used to convert the driver output into an alternating current so that no direct current is applied to the liquid crystal. D0 to D7 are signals for providing data for display to the segment drivers 2a to 2c.

FIGS. 2A to 2D show that the number of horizontal dots is three.
It is a time chart which performs detection in the case of 60 dots and a data bus width of 8 bits. In order to detect the number of horizontal dots, “H” is output to EIO1 as shown in FIG. 2A, and the line shift pulse L is output as shown in FIG. 2B.
P is output by one pulse. Next, while monitoring EIO2 and counting the number of data shift clocks, FIG.
As shown in FIG. 2C, the data shift clock XCK continues to be output, and as shown in FIG.
Know the value of XCK at the time of. This number is multiplied by the number of bits of the data bus to detect the number of dots in the horizontal direction.

FIGS. 3A to 3C show that the number of vertical dots is two.
It is a time chart which performs detection of 40 dots. next,
In order to detect the number of dots in the vertical direction, as shown in FIG. 3A, "H" is output to DIO1, DIO2 is monitored, and while the number of line shift pulses is counted, FIG. As shown in FIG. 3, the line shift pulse LP is continuously output, and as shown in FIG.
Know the value of LP at the time This value is the number of dots in the vertical direction. Thereby, actual display is performed by adjusting various settings inside the display controller to the numbers of horizontal and vertical dots.

FIG. 4 is a block diagram of a liquid crystal display device of a simple matrix system, and reference numerals in the drawing are the same as those in FIG. The display device includes an LCD panel 1 for performing actual display, and segment drivers 2a to 2 for performing horizontal display.
c (in the case of using three) and common drivers 3a and 3b (in the case of using two) for displaying in the vertical direction. The segment drivers 2a to 2c include display data buses D0 to D7.
(In the present embodiment, eight lines of an 8-bit configuration), data shift clock XCK, line shift pulse LP, frame inversion signal M, data enable signal EIO1 (input), EI
O2 (output) and the like are connected.

On the other hand, LP, M, etc. are connected to the common drivers 3a and 3b as in the case of the scan start signals DIO1 (input) and DIO2 (output) segments. Among these signals, EIO1 and EIO2 are transmitted from the horizontal segment driver 2a to 2b and 2c, and when the data for one line is completely captured, the EIO of the segment driver 2c is output.
2 and can be used to detect the number of dots in the horizontal direction. Similarly, DIO1 and DIO2 are transmitted from the vertical common drivers 3a to 3b, and when the vertical display is completed (one screen is completed), the DIO of the common driver 3b is transmitted.
2 and can be used to detect the number of dots in the vertical direction.

FIGS. 5A to 5G are timing charts when the display data is taken into the segment driver. As shown in FIG. 5B, when the line shift pulse LP falls, as shown in FIG. 5A, the "H" level is taken into the EIO1 of the segment driver 2a in FIG. As shown in FIG. 5), when the data shift clock XCK falls, as shown in FIG. 5D, the values of the display data buses D0 to D7 are taken in the driver, and the "H" level taken in from the EIO1 changes. It is shifted by an internal shift register. When this repetition is repeated (the number of dots of the segment driver / the number of data bits) times, as shown in FIG.
"H" level is output to IO2. This EIO2 is
It is connected to the EIO1 of the next-stage segment driver 2b, and is shifted by an internal shift register at the next data shift clock, as shown in FIG. Similarly,
As shown in FIG. 5 (g), the segment driver 2c
When the IO1 signal is shifted and data for one line is completed, an "H" level is output to EIO2. Normally, EIO1 and EIO2 are for cascade connection, and the last stage EIO2 is not connected anywhere.

FIGS. 6A to 6D are time charts of signals to the common driver when a selection pulse is output. As shown in FIG. 6A, "H" level is given to DIO1 connected to the common driver 3a at the beginning of one screen, and as shown in FIG. 6B, the falling edge of the line shift pulse LP Sometimes, it is fetched internally and a selection pulse is output on the first line. This “H” level is shifted by the internal shift register at each falling edge of the line shift pulse, the selection pulse shifts to the second line and the third line, and the line shift pulse reaches the output number of the common driver. After that, as shown in FIG.
2 outputs an “H” level to the common driver 3 in the next stage.
b is taken in from DIO1. The common driver 3b is similarly shifted. When the line shift pulse for one screen is output, the “H” level is applied again to DIO1 of the common driver 3a in the first stage. As shown in FIG. 6D, the DIO2 at the last stage of the common driver is the EIO2 at the last stage of the segment driver.
Similarly, it is not connected anywhere.

[0025]

As is apparent from the above description, according to the present invention, the signal already in the driver is used without using a special identification signal as in the prior art.
Not only does it not require a special circuit, but it can also use a free dot size as long as it can be displayed by the controller in the main body, so that the range of application is widened.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a display control device of a liquid crystal display system according to the present invention.

FIG. 2 is a timing chart for detecting the number of horizontal dots in the present invention.

FIG. 3 is a timing chart for detecting the number of vertical dots in the present invention.

FIG. 4 is a block diagram of a simple matrix system according to the present invention.

FIG. 5 is a timing chart for capturing segment driver data according to the present invention.

FIG. 6 is a timing chart for generating a common driver selection pulse according to the present invention.

FIG. 7 is an external view of a case where a conventional display device and a main computer are detachable.

FIG. 8 is a diagram showing a conventional example for setting output timing of display data.

[Explanation of symbols]

1 LCD panel, 2a to 2c segment driver,
3a to 3b: Common driver, 4: Connector.

Claims (1)

(57) [Claims] 1. A plurality of liquid crystal display portions having different numbers of display pixels
In an electronic device which can be used by attaching and detaching, and using a simple matrix system as a liquid crystal display system, a data shift clock is used for a liquid crystal display portion of the mounted liquid crystal display portion using a cascade connection signal of a liquid crystal drive driver . applied to segment <br/> instrument driver, a first monitor means for monitoring a cascade signal from the final element of the segment driver while counting the number of said clock pulses, the number of clocks when the cascade signal is output the liquid crystal display unit and the first detecting means for detecting the number of horizontal dots by a value obtained by multiplying the number of data bits, the line shift pulse which is the mounting on
Given to minute common driver, and the second monitor means for monitoring a cascade signal from the final element of the common driver while counting the number of said clock pulses, the number of clocks when the cascade signal is output vertical Second detecting means for detecting the number of dots ,
The number of horizontal dots detected by the first detection means and
Match the number of vertical dots detected by the second detection means
Drive control of the mounted liquid crystal display part.
A display control device for a liquid crystal display system.