KR19990080023A - Display device for automatically adjusting image position according to display mode change and computer system using same - Google Patents

Abstract

The present invention relates to a method for automatically adjusting the image position of a display device, the host having a video controller that supports multiple display modes by the resolution and a driver (or application) for generating display mode information by changing the display mode And a display device for displaying a display mode corresponding to any one of the multiple display modes from the host, and an interface unit for transmitting the display mode information generated according to the display mode change from the host to the display device. The interface unit has a display data channel (USB) or display data channel (DDC) protocol and is provided in both the host and the display device. Therefore, the microcomputer of the display apparatus receives display mode information corresponding to the display mode to be changed through USB or DDC from a driver (or an application program) generating display mode information of the host. A synchronization signal is generated in response to the display mode information, thereby outputting the pixel clock and the sampling clock to the LCD driving circuit to accurately display the position of the image according to the change of the display mode.

Description

DISPLAY APPARATUS ADJUSTING IMAGE POSITION AUTOMATICALLY BY CHANGE OF DISPLAY MODE AND COMPUTER SYSTEM FOR USE WITH THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a computer system using the same, and more particularly to pixels or dots driven by digital video data, such as a liquid crystal display device. A display apparatus comprising: a host generating display mode information including a resolution and a pixel clock frequency according to a display mode change, and receiving the display mode information through a universal serial bus (USB) or a display data channel (DDC). A liquid crystal display device for automatically adjusting a position of an image according to a display mode.

As an example of a general display device having pixels for performing color display driven according to digital video data, the liquid crystal display device shown in FIG. 1 includes an LCD control device 20 and an LCD panel 30. In addition, horizontal and vertical synchronization signals Hsync and Vsync are received according to the display modes supported by the host 10 to display an image corresponding to the display modes.

In addition, the LCD panel 30 is provided with an LCD driving circuit 40. This drives the display panel 40 by receiving information corresponding to the display mode (for example, a sync signal according to the resolution or the number of display colors and the digital RGB signal) from the LCD control circuit 20.

The LCD control apparatus 20 includes a microcomputer (not shown), which receives horizontal and vertical synchronization signals (Hsync, Vsync) according to a change in the display mode provided from the host 10, and the resolution of the display mode. Determine. The pixel clock and the sampling clock of the determined display mode are generated.

However, the LCD controller 20 receives the horizontal and vertical synchronization signals (Hsync, Vsync) from the host 10 and infers the display mode that is closest to the corresponding display mode, thereby making it difficult to determine the exact display mode required by the host. Therefore, the image may not be displayed correctly in the center of the screen of the LCD panel 30.

Therefore, the user must adjust the position of the image to the center according to the changed display mode.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problem, and in a liquid crystal display having a multiple display mode according to a change of the display mode and a computer system using the same, corresponding to the display mode to be changed when changing the display mode. This is to implement a host that generates display mode information.

In addition, another object of the present invention is to implement a liquid crystal display device which receives the display mode information and automatically adjusts and displays the position of the image according to the display mode.

1 is a block diagram schematically showing the configuration of a general liquid crystal display device;

2 is a block diagram showing a connection configuration between a liquid crystal display device and a computer system according to an embodiment of the present invention;

3 is a block diagram showing a detailed configuration of an LCD control device of the liquid crystal display device shown in FIG. 2; And

4 is a flowchart illustrating a processing procedure according to an embodiment of the driver shown in FIG. 2.

* Description of symbols on the main parts of the drawings *

100: host 110: driver (or application)

200: liquid crystal display device 120, 210: interface unit

220: LCD control unit 222: microcomputer

224 PLL circuit 226 AD converter

228 scaling engine 230 LCD panel

240: LCD drive circuit

According to one aspect of the present invention for achieving the above object, in a computer system having a multiple display mode: generating the other display mode information according to the change of the display mode from one of the multiple display mode to another A host; A display device which receives the display mode information and performs a display operation corresponding to the display mode; The host and the display apparatus each include an interface unit for mutually transmitting the display mode information by a predetermined protocol.

In a preferred embodiment of this aspect, the host includes a driver (or application) for generating the display mode information.

In this embodiment, the display mode information includes the resolution and the dot clock rate of the display mode to be changed.

In this embodiment, the interface unit includes a Universal Serial Bus (USB) or Display Data Channel (DDC) protocol.

In a preferred embodiment of this aspect, the display apparatus includes a microcomputer that receives the display mode information and generates a synchronization signal corresponding to the display mode.

According to another aspect of the present invention for achieving the above object, a display apparatus for use with a host that generates display mode information in accordance with a display mode change: an interface unit for accepting the display mode information by a predetermined protocol and; A control circuit for receiving the display mode information from the interface unit and generating a synchronization signal and a pixel clock corresponding to the display mode; And a display unit to be displayed in the corresponding display mode in response to the synchronization signal and the pixel clock.

In a preferred embodiment of this aspect, the control circuit comprises: a microcomputer that receives the display mode information and generates a synchronization signal corresponding to the display mode; A clock generation circuit for generating a pixel clock and a sampling clock for displaying the display mode in response to the synchronization signal; An AD converter which receives the analog video data and generates a digital video signal synchronized with the sampling clock; And a scaling engine that receives information corresponding to the display mode information from the microcomputer and digital video data from the AD converter, and outputs a synchronization signal and a pixel clock according to the display mode.

In a preferred embodiment of this aspect, the interface unit has a Universal Serial Bus (USB) or Display Data Channel (DDC) protocol.

Therefore, according to the present invention, display mode information corresponding to the display mode to be changed is generated as the display mode is changed from a driver or an application program that drives the display mode of the host. It is then transmitted to the display device via an interface unit such as USB or DDC. The display mode information is received by the interface unit having the same protocol, and the display mode information is transmitted to the microcomputer. The microcomputer generates a synchronization signal corresponding to the display mode information. The PLL circuit then generates a pixel clock and a sampling clock corresponding to the synchronization signal. As a result, the scaling engine provides the digital video signal, the synchronization signal, and the pixel clock corresponding to the display mode to the LCD driving circuit. Thus, the LCD panel displays video information according to the display mode in the center of the screen.

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

2 shows a configuration of a computer system having a host and a liquid crystal display device according to an embodiment of the present invention.

Referring to the drawings, the computer system is connected to the USB root hub 120 through a host 100 having a root USB hub 120 and a USB hub 210 to display an image 200. Include.

The host 100 includes a video controller (not shown) that supports multiple display modes according to resolution and a driver (or application) 110 that generates display mode information according to a change of display mode. And an interface unit 120 having a USB protocol or a DDC protocol for transmitting video information (eg, RGB signals, horizontal and vertical synchronization signals) and display mode information to the liquid crystal display apparatus 200. Accordingly, video information and horizontal and vertical synchronization signals are transmitted to the liquid crystal display device through the transmission path 130 having the USB protocol or the DDC protocol.

For example, as shown in FIG. 4, the driver 110 follows the following control procedure. That is, if the display mode change is requested from the user in step S112, the request is accepted. In step S114, the display mode to be changed is determined. Subsequently, display mode information (e.g., resolution and pixel clock frequency, etc.) corresponding to the display mode determined in step S116 is generated.

Therefore, when the display mode needs to be changed, the driver 110 can operate the control procedure at any time. The driver 110 may be provided as a driver of a video controller (not shown), a device controller of a window type operating system program, and the like, and may also be provided as an application program.

Referring back to FIG. 2, the liquid crystal display device 200 includes a USB hub 210, an LCD control device 220, and an LCD panel 230.

The USB hub 210 receives video information, horizontal and vertical synchronization signals, and display mode information input from the host 100 through the transmission path 130 and transmits the received information to the LCD controller 220. It processes information that is input by the same protocol as that of 120 of the host 100 (eg, USB or DDC, etc.).

The LCD control circuit 220 generates a pixel clock and a sampling clock corresponding to the display mode information.

The LCD panel 230 includes an LCD driving circuit 240.

Specifically, referring to FIG. 3, the LCD control circuit 220 according to an embodiment includes a novel microcomputer 222. And an AD converter 226, a PLL circuit 224, and a scaling engine 228.

The microcomputer 222 receives horizontal and vertical synchronization signals Hsync and Vsync from the USB hub 210 and outputs respective horizontal and vertical synchronization signals Hneg and Vneg having a specific polarity. For example, when the LCD device 200 has a characteristic of being operated in synchronization with a negative polarity vertical and horizontal synchronizing signal, the LCD device 200 outputs a negative horizontal synchronizing signal Hneg and a vertical synchronizing signal Vneg. . In addition, the display mode information (Mod_inf) is received and information (Mod_inf ') corresponding to the display mode currently supported by the host 100 is provided to the scaling engine 228 through the I ² C bus 232.

The AD converter 226 converts each of the analog R, G, and B video signals into digital R, G, and B video signals, and converts each of the R, G, and B signals into odd and even signals (Odd, Even). And print them separately.

The PLL circuit 224 receives the negative horizontal synchronization signal Hneg provided from the microcomputer 222 to each pixel clock W_Dclk and R_Dclk according to a write / read operation of a line memory (not shown). Is generated and provided to the scaling engine 228. The pixel clock R_Dclk according to the readout is provided to the sampling clock Sample_clk of the AD converter 226.

The scaling engine 228 may internally output the digital video signals Odd and Even provided from the AD converter 226 in response to a plurality of control signals provided from the microcomputer 222 and the PLL circuit 224. It is stored in a line memory (not shown) provided in the. In this case, the scaling operation is performed according to the information Mod_inf 'corresponding to the display mode information Mod_inf provided from the microcomputer 222. A digital video signal, a synchronization signal, and a pixel clock are provided to the LCD panel.

Subsequently, the LCD driving circuit 240 outputs the digital video signals digits R, G, and B and the synchronization signal Hsync 'outputted from the LCD controller 220 by the pixel clock D_clk and the sampling clock Sample_clk. , Vsync ') and operate to display the LCD panel 230.

As a result, the image corresponding to the display mode to be changed is accurately displayed on the LCD panel 230 in the center of the screen.

As described above, the present invention includes a host for outputting display mode information according to a change of the display mode, receives display mode information corresponding to the display mode to be changed from the host, and displays the corresponding display mode through the information. It is located in the center of the screen.

Claims (8)

In a computer system with multiple display modes: A host for generating the other display mode information according to the change of the display mode from one of the multiple display modes to the other; A display device which receives the display mode information and performs a display operation corresponding to the display mode; And the host and the display device each include an interface unit for mutually transmitting the display mode information by a predetermined protocol. The method of claim 1, The host includes a driver (or application) for generating the display mode information. The method according to claim 1 and 2, The display mode information includes a resolution and a dot clock rate of the display mode to be changed. The method of claim 1, The interface unit is a computer system having a Universal Serial Bus (USB) or Display Data Channel (DDC) protocol. The method of claim 1 And the display device includes a microcomputer that receives the display mode information and generates a synchronization signal corresponding to the display mode. A display apparatus for use with a host that generates display mode information according to a change of display mode: An interface unit which receives the display mode information by a predetermined protocol; A control circuit for receiving the display mode information from the interface unit and generating a synchronization signal and a pixel clock corresponding to the display mode; And a display unit to be displayed in a corresponding display mode in response to the synchronization signal and the pixel clock. The method of claim 6, The control circuit is: A microcomputer which receives the display mode information and generates a synchronization signal corresponding to the display mode; A clock generation circuit for generating a pixel clock and a sampling clock for displaying the display mode in response to the synchronization signal; An AD converter which receives the analog video data and generates a digital video signal synchronized with the sampling clock; And a scaling engine that receives information corresponding to the display mode information from the microcomputer and digital video data from the AD converter, and outputs a synchronization signal and a pixel clock according to the display mode. The method of claim 7, wherein The interface unit is a display device having a Universal Serial Bus (USB) or Display Data Channel (DDC) protocol.