JP2001013937A - Device and method for driving plural display devices to be chained, chainable display device and chained display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain easiness of extension by enabling many display devices to be chainingly connected in a state of which physical restrictions from respective devices are eliminated without changing the hardware of a system side. SOLUTION: This system is provided with a display driving device 1 outputting a video signal which is to be displayed with respect display areas and a chained display signal which is to be added to the video signal and also which uses at least the timing of one line, a first display device 2(1) capable of displaying a video with respect the display area of itself based on the video signal by inputting the video signal and the chained display signal and also by analyzing the chained display signal while being connected to the device 1 and a second display device 2(2) capable of displaying the video with respect to the display area of itself based on the video signal by inputting the video signal and the chained display signal and also by analyzing the chained display signal while being connected to the first display device 2(1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using an LCD panel or the like, and more particularly, to a driving method for driving a plurality of display devices to be chained, a driving device, and a display device capable of chain connection. , And a chain display system.

[0002]

2. Description of the Related Art In recent years, there has been proposed a technique in which a plurality of display panels are connected to a personal computer (PC), and small display panels are integrated into a plurality of display panels to be used as a display having one large screen as a whole.
At this time, according to the specification of the normal interface, only one display panel is displayed per one video chip. For example, when trying to display different images on four display panels, four video chips are required. . For this reason, even if an attempt is made to display a large number of display panels under a normal interface, only about 4 to 8 panels can be connected at the maximum due to the limitations of the space and slots in the PC housing and the number of connections. The expansion of the panel was also limited. In addition, the conventional method uses four video chips for four video chips.
When displaying different images on one display panel, for a certain period of time, the CPU in the PC only updates (UPDATE) the memory of one video chip. Therefore, during this time, the memories in the remaining three video chips only had the function of holding the screen.

Here, Japanese Patent Application Laid-Open No. Hei 9-319550 discloses a conventional technique for connecting a plurality of display devices (monitor devices) to one PC device. In this prior art, a plurality of display devices are used, and these display devices are connected in parallel to a PC device capable of processing a plurality of programs in parallel. Each display device uses a store instruction key provided in itself. Whether or not the video signal can be captured is selected by an operation or a store instruction signal sent from the PC device, and the video can be displayed based on the selection result. According to this technique, it is possible to display an image on each display device without limiting the number of parallel execution programs by the hardware configuration. Similarly, JP-A-9-274475 discloses a conventional technique for connecting a plurality of display devices to one PC. This publication discloses a technique in which ID information is inserted immediately before video data of the first line for each frame, and video data is taken in only when the ID matches a preset ID in each display device. . According to this technique, a plurality of display devices can be driven by one system output from the PC device, and wiring can be simplified.

On the other hand, in recent years, digital interfaces have been introduced mainly for notebook PCs, and at present, they are used only by connecting the PC and the display one-to-one. The technology for connecting multiple displays in a daisy chain state using this digital interface is described in Gigabit Video Interface by Sony Corporation.
(GVIF) application note. In the future, it is expected that the manner of connecting and using digital interfaces in a chained state will increase more and more.

[0005]

However, in the technique described in Japanese Patent Application Laid-Open No. 9-319550, since each display device is connected in parallel, an interface is provided between the PC device and the display device. And wiring becomes complicated. In addition, a store signal detection circuit must be provided for each display device, which complicates the hardware configuration. Further, in the technology described in Japanese Patent Application Laid-Open No. 9-274475, an ID setting circuit must be provided for each display device, and it is necessary to set an ID every time the number of units is changed. The operation in the device becomes complicated. Further, this publication merely discloses the collation of the ID information, and does not allow the PC device to perform different control for each display device.

Furthermore, in order to achieve the above-described GVIF technology, it is necessary to construct new hardware and provide a video port with a new display control circuit. Also,
When sending command information, such as how to write screen information to which display device and how to control the display device, to the chained display device, only the technology presented here is used. Then, it is necessary to send such information separately from the video signal. In such cases, not only software changes,
It is necessary to change hardware and increase the number of interface lines.

[0007] The present invention has been made to solve the above technical problems.
An object of the present invention is to make it possible to connect more display devices while excluding physical restrictions from each device, thereby facilitating expansion.

Another object of the present invention is to make it possible to transmit command information to a chain of display devices without changing hardware on the system side. Command information is transmitted by rewriting a register in the chip, and can be automatically transmitted without being distinguished from screen information.

Still another object is to enable enlarged display using a large number of display devices connected in a chain by a simple software change, and more specifically, a large number of display devices connected in a chain. The screen information is individually divided and enlarged and displayed on the display device based on the command information.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a driving method for driving a plurality of display devices to be chained, the display method comprising: In addition, a display timing that is not displayed in this display area is added, and a control command for controlling the display device is written in response to the added display timing. It is characterized by including selection information for selecting a device and control information of the selected display device.

The display timing that is not displayed in the display area of the display device may be any of up, down, left and right in the display area, but there is a method using a blanking at the end of each line corresponding to the right side of the display area, According to the method of using the predetermined line after the end of the frame corresponding to the lower side, since the display standard is generally at the left end, there is no need to change the display standard in this image display. In particular, it is preferable to use timing for forming at least one line formed after the last line in the display area since blanking at the end of each line can be reduced.

The control command used here is constituted by a command line including a header block portion and a command block portion, and the header block portion is a block including header information required for linking the display devices. Characteristically, command information such as how to write screen information to which display device and how to control the display device by changing software only without changing hardware. Is preferable in that it can be transmitted. Further, the header information includes version information of the chain display control software, an automatic increase ID that increases each time the display device is connected to the connected display device, and the like.

Further, in this driving method, the same screen information is sent to a plurality of display devices for forming a large screen by enlarged display, and the selection information is used for forming a large screen by enlarged display. If the control information includes selection information for selecting all of the plurality of display devices, and the control information is characterized in that the screen information is individually enlarged and displayed on the display device constituting the large screen, for example, the resolution is increased by increasing the resolution. It is preferable that a new update operation for one image is not required for display. In particular, using a liquid crystal display (LCD) as a display device is advantageous in that connection of each screen is easy when a large screen is formed by a plurality of display devices.

Further, the present invention is a driving method for driving a plurality of display devices to be linked, wherein a display timing for visualizing an image in a display area of the display device is provided.
A display timing that is not displayed in the display area is added, and a control command for controlling the display device is written for the added display timing, and the control command is updated each time the display device passes through a plurality of display devices to be chained. If each display device loses its own ID information at the time of initializing, for example, turning on / off the power of the device, the control command is received by receiving this control command. ID
Is preferred because it can be automatically provided. In particular, if the ID information is configured to be automatically added each time it passes through a plurality of linked display devices, it is effective in that the software can be simplified and the function can be achieved.

Further, the display device is configured to recognize its own ID based on the ID information and execute the display operation based on the instruction information of the ID to be displayed included in the control command. This is preferable in that a display operation can be executed by freely selecting each chained display device without individually setting an ID in each display device.

On the other hand, the present invention relates to a driving device for driving a plurality of display devices to be chained, wherein a video signal generating means for generating a video signal for displaying a video on a display area of the display device; Chain display signal generating means for generating a chain display signal using display timing not used for video display of the display area based on the video signal to be generated, and generating a chain signal by the chain display signal generation means by the video signal generation. Output means for adding to the video signal generated by the means and outputting the chained display signal to any of the chained display devices.

In particular, the chain display signal generated by the chain display signal generating means is a chain display signal using at least one line of timing not used for video display of the display area based on the generated video signal. Is preferable because it is not necessary to change the display reference in the image display, and the display devices connected in a chain can be controlled by adding a simple display timing.
Further, the chain display signal generated by the chain display signal generating means includes selection information of which display device is to be selected from a plurality of chained display devices, and control information for controlling the selected display device. The feature is that it is possible to specify an arbitrary device from the chained display device only by changing the software and execute the video display without changing the hardware or increasing the number of interface lines. Become.

The chain display signal generated by the chain display signal generating means includes selection information for selecting all of the plurality of display devices to be chained, and the same video signal generated by the video signal generating means is chained. The plurality of display devices may be configured to be transmitted in a chain to all of the plurality of display devices. It is preferable to include control information for enlarging and displaying the video signal on each display device, since a plurality of display devices connected in a chain can be combined to form a large screen. The driving device according to the present invention can be realized as an aspect of a video card or the like, such as an additional board or the like connected to a connector inside the PC.

Still further, according to the present invention, a display driving device that outputs a video signal to be displayed on a chained display device and a control command for controlling the chained display device can be connected in a chained state. A digital receiver for inputting a video signal output from a display driving device and a control command added to the video signal and formed at a display timing that is not displayed, and a digital signal input from the digital receiver. A control circuit for analyzing a control command; a frame memory for storing a video signal; and a digital transmitter for outputting the video signal and a control command added to the video signal to a connected display device. It is characterized by. Instead of having a memory for holding screen information on the system side, which is a display drive device,
By providing this frame memory on the display device side, it is possible to display images on a large number of display devices with a single display control circuit.

In this display device, the control circuit determines whether or not to display a video signal on its own display device according to the analyzed control command, and the digital transmitter converts the video signal generated by the control circuit into a video signal. Regardless of the determination as to whether or not to display, it is preferable that the video signal and the control command are output to the next connected display device in that they can function as a simple buffer. . Here, the control command output from the digital transmitter does not necessarily need to match the control command input by the digital receiver,
For example, the contents may be partially different, such as the added ID information. Similarly, the video signals do not necessarily have to match, but if the video signals are output to other display devices as they are, there is no need to perform the video signal change processing.

Further, the chain display system according to the present invention comprises a video signal to be displayed on a display area and a chain display signal which is added to the video signal and uses at least one line timing not used for video display. And a display driver connected to the display driver and inputting a video signal and a chained display signal, analyzing the chained display signal, and based on the video signal, with respect to its own display area. The first to enable video display
And a display device connected to the first display device for inputting a video signal and a chain display signal, analyzing the chain display signal, and displaying an image on its own display area based on the video signal. And a second display device capable of performing the operation. Here, the video display on each display device does not necessarily need to be the entire video signal, and may be a partial display. In particular,
When enlarged display is performed using four or more display devices, the divided video may be enlarged and displayed. Also, the first
The chained display signal input to the display device and the chained display signal input to the second display device do not necessarily have to match as described above, and different information such as added ID information may be used. There is no problem even if it includes.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 Hereinafter, the present invention will be described in detail based on an embodiment shown in the accompanying drawings. FIG. 1 is a block diagram showing one embodiment of a chain display system to which the present invention is applied.
In FIG. 1, reference numeral 1 denotes a personal computer.
(PC), which has a role as a driving device for driving the display device in the present embodiment. In the personal computer 1, reference numeral 12 denotes an input / output circuit including a keyboard and a mouse, and reference numeral 13 denotes an RA including a hard disk or an IC storing data such as a video signal.
M and 14 are ROMs in which control programs are stored.
The video signal used for display may be created by the personal computer 1 itself in the present embodiment, or may take in a video signal generated externally. Reference numeral 11 denotes a CPU, which executes an execution process of the personal computer 1 based on a control program from the ROM 14, a user instruction from the input / output circuit 12, and the like. Further, reference numeral 15 denotes a display control circuit. The display control circuit 15 is controlled by the CPU 11 and controls how to write a video signal (screen information) to the connected display panel and how to control the display panel such as a brightness control. This is a circuit that controls a display device such as a display device, and generates a command line including a control command, and adds this command line to a video signal (screen information) and outputs it to a display panel described later. .

Further, in FIG. 1, reference numerals 2 (1) to 2 (n)
In this embodiment, a liquid crystal panel (LCD) is used, and a plurality of display panels 2 (1) to 2 (n) are connected and connected in a chain state (daisy chain state). This display panel 2 (1) ~
2 (n), reference numeral 21 denotes a digital receiver for receiving a video signal (screen information) and a chain display signal (control command), and 22 denotes a digital receiver for outputting the screen information and the control command to a connected display panel. Transmitter. Here, the digital receiver 21 in the first display panel 2 (1) receives the output from the display control circuit 15 of the personal computer 1, and the digital receiver 21 in the second display panel 2 (2) First
Transmitter 2 on display panel 2 (1)
2 is being received. Similarly, the digital receiver 21 of the n-th display panel 2 (n) receives the output from the digital transmitter 22 of the (n-1) -th display panel 2 (n-1) not shown, These transceivers enable a chained state as a system.

Reference numeral 23 denotes a control circuit for controlling each of the display panels 2 (1) to 2 (n) based on the control command received by the digital receiver 21, and reference numeral 24 denotes a control circuit which is received by the digital receiver 21. A frame memory 25 for storing the screen information stored therein; a liquid crystal display control circuit 25 for sequentially taking out information for one screen stored in the frame memory 24 and controlling a liquid crystal display circuit 26 described later;
Is controlled by the liquid crystal display control circuit 25 and LC
This is a liquid crystal display circuit that actually displays an image on the screen of D.

FIG. 2 shows a display panel 2 (1) generated by the display control circuit 15 of the personal computer 1.
FIG. 4 is an explanatory diagram showing the relationship between screen information and control commands sent to .about.2 (n). In the present embodiment, the command is transmitted with a command line 32 as a control command added after the last line of the display area 31 actually displayed on the display panels 2 (1) to 2 (n). . In the present embodiment, as shown in FIG.
XGA (eXtended Gr) with a display resolution of 024 × 768
aphics Array) and display area 3
1 is 1024 dots in the data line direction and 7 in the gate line direction.
The command line 32 is formed by 68 lines, and the command line 32 is formed on the 769th line next to the 768 line. As described above, this command line 32 includes display panels 2 (1) to 2 (n) to which screen information is to be written.
, And a control command indicating how to control the selected display panel, and the like. The display panels 2 (1) to 2 (n), which have received the screen information of the display area 31 and the control command formed on the command line 32, analyze the control command and determine whether or not there is display on its own panel. Have decided how.

FIG. 3 shows a format of a command line according to the present embodiment. The command line in this embodiment has two parts, a header block 41 and a command block 42, in one display timing. The header block 41 is a portion corresponding to so-called header information such as version information, a total number of instructions (CHECK SUM) used for noise check, and an automatic increase ID, and has a fixed length in the present embodiment. On the other hand, the command block 42
Is composed of a set of two dots, and expresses one command in units of two dots. The first dot includes an ID number for executing the command, a command number, whether or not the command is unique, whether or not the ID command is valid (enabled), and the like. The data value corresponding to the command of the dot is stored.
Assuming that the beginning of the command line is the 0th dot, even-numbered dots are arranged in the command block 42 to correspond to the first dot, and odd-numbered dots are arranged to correspond to the second dot.

Further, at present, a 6-bit digital interface is predominant, and when considering an 8-bit digital interface, it is preferable not to use 2 bits of LSB (least significant bit).
The B2 bit is reserved. Further, since three data of red (R), green (G), and blue (B) exist for each dot of the display, a maximum of 6
It is possible to express command information for each dot using 18 × 3 bits. Further, in the present embodiment,
The 0th to 15th dots of the command line are defined as a header block 41, and the 16th and subsequent dots are defined as a command block 4
It is 2. Unused portions in both blocks are reserved. In the present embodiment, different display screens can be displayed on a plurality of display panels by the interface using the command line, and the format based on these concepts is defined as MDA (Multipl.
e Display Architecture).

Here, the header block 41 in the present embodiment includes the following items. (1) Name (MDA id with MDA on valid) (1 dot) (2) Version information (Version) (1 dot) (3) Horizontal resolution (1 dot) (4) Vertical resolution (Vertical resolution) (1 dot) (5) Auto increment ID (1 dot) (6) MDA command line enable / disable instruction (MDA command lin)
e enable) (1 dot) (7) Command line total number (1)
(8) Check sum of MDA line (1 dot) (9) Test mode enable / disable (1 dot) (10) Reserve (7 dots)

The name (1), which is the first dot of the header block 41, indicates that this format is MDA, and is used to confirm whether the MDA instruction line is valid or invalid. The following (2) version information is used when the MDA format is changed, and (3) horizontal resolution and (4) vertical resolution indicate a resolution of 1024 × 768 in the present embodiment. Also, (5) the automatic increase ID is displayed on the display panels 2 (1) to 2 (1) connected in a chain from the personal computer 1 side.
It is a value that automatically increases each time 2 (n) is passed, and each display panel can automatically have its own ID without having to specially set its own ID. This auto increment ID
Thus, even if the user loses his / her ID information at the time of the initial state such as when the power is turned off / on, the MD
A format automatically receives your I
D can be recognized.

(6) The MDA command line valid / invalid instruction is used for protection during updating of the MDA command line and the like, and the data on the chained digital signal is parallelized. When the data is converted into serial data, error transfer of data due to a delay in following is prevented, and the information is automatically time-limited. next
(7) The total number of MDA instructions is used when increasing the number of MDA command lines, and the number of MDA command lines is not limited to one as in this embodiment. Can be sent. (8) The total number of MDA instructions is a check performed by adding whether or not the information is correct and whether there is noise on the command line and the data is not garbled. This embodiment is particularly effective in this embodiment because it is easy. Regarding the next (9) test mode valid / invalid, a test item can be entered by setting this bit, and can be used for, for example, confirmation of connection. The next (1
0) is a spare part.

FIG. 4 shows an example of data insertion into the first 0 dot and 1 dot in the header block 41. The header block including the above-described items contains, for example, values as shown in FIG. Each of the 0 dots on the left side of FIG.
The names of M (2Dh), D (24h) and A (21h) are written using the upper 2 bits (2 bits from the most significant bit (MSB)) of data, G data and B data and the lower 4 bits. ing. Further, in the next one dot on the right side in FIG. 4, version information using R, G, B data is written as (2) version information.

Next, the command block 42 in the present embodiment will be described. In the command block 42 following the header block 41, for example, the following items are described. (1) Brightness control (2) Contrast control (3) Gamma control (4) White balance (5) Power save mode-Backlight off
and LCD logic off) (6) Freeze and Refres
h) (7) Display disable / enabl (Display disable / enabl)
e, blue back) (8) Expansion ratio (horizontal / vertical) (Expansion ratio (H / V)) (9)-(12) Start position and end position of input data capture
(Horizontal / Vertical) (Start (End) position of image H (V) written in fram
e memory) (13) to (16) Display start (end) position on LCD (horizontal /
(Vertical) (Display start (end) position H (V) in UXGA (SXGA, XG
(A) screen) (17) Extra frame part valid / invalid (Border color) (18) Four SVGAs are displayed on UXGA (Four SVGA to
UXGA)

The first items of the command block 42, (1) brightness control and (2) contrast control, adjust and control the brightness and contrast of the display panels 2 (1) to 2 (n) performing the display operation. (3) Gamma control is performed according to a gamma correction curve for input / output adjustment.
This is for giving a reference voltage to the CD. Further, (4) white adjustment is a white point adjustment value for determining a hue level, and (5) power saving mode is an item relating to power saving mode setting such as turning off a backlight and turning off an LCD circuit. (6) Screen information retention and screen information update indicate the time during which the MDA command is not accepted even if given, and (7) Display valid / invalid (blue when invalid) is appropriate when an inappropriate signal is received. (8) Enlarged display ratio indicates the enlargement ratio in the horizontal and vertical directions. Further, (9)-(12) input data capture start position and end position are registers for setting which portion of data sent from the display device is to be captured, and (13)-(16) The display start (end) position on the LCD is a register for setting where and how the captured data is displayed on the LCD. (17) The remaining frame portion, valid / invalid is determined by VGA (Video g
raphics Array) (640 x 480)
This register is used to set whether or not to color the surplus portion when displayed in (1024 × 768). Furthermore,
(18) The four SVGAs are displayed on the UXGA by the SVGA (s
upper VGA) (800 × 600) input data and UXGA (1
This register is used when displaying (600 × 1200).

FIG. 5 shows an example of command insertion in the command block 42. In this embodiment, one command is composed of two dots as shown in FIG.
The first dot (2n dot) represents the command, the next dot
(2n + 1 dot) describes the parameters. In the example of FIG. 5, the first bit from the MSB of the R data indicates whether the command is enabled (Valid or Invalid), and the next bit indicates whether the command is enabled on each display panel 2.
Whether it is common to (1) to 2 (n) or unique to each display panel (Common or Uniqu
e). Command of this bit (Common or Uni
que) is a command effective when the same image is displayed and output on a plurality of display panels 2 (1) to 2 (n). Next, the ID is determined by the lower bit and the G data.
A command is formed, and up to 256 display panels can be selected by 8 bits of ID7 to ID0. The 6 bits from the MSB in the next B data indicate where in the display register the data is to be applied.
3 shows internal register addresses in the control circuit 23 of the display panels 2 (1) to 2 (n).

In the next dot, 2n + 1 dot shown in FIG. 5, a value corresponding to a command of 2n dot is stored. In other words, a display panel having an ID specified by 2n dots describes data to be executed with respect to the specified internal register address, and the higher order in each of R, G, and B data is described. Actual display is performed on the display panels 2 (1) to 2 (n) based on the data of 2n + 1 dots using all 6 bits. For example, in the case of the above (13) command indicating the display start position on the LCD, the contents of the data stored in the internal register by the 2n and 2n + 1 dots are used as the start position in the display position on the LCD. ing.

The flow of displaying screen information on, for example, a display panel of No. 3 using the MDA format employing the header block 41 and the command block 42 in the command line 32 as described above will be described mainly with reference to FIG. This will be described with reference to a block diagram.

First, the display control circuit 15 in the personal computer 1 is controlled by a program executed by the CPU 11 to generate a command line 32 following the screen information. In the command line generated at this time, (5) Automatic increase ID (Aut
o Set 1 to increment ID). Further, 3 is set to the ID of the 2n dot command in the command block 42, and 6 (Freeze and Refresh) is set to A5 to A0. The data content at 2n + 1 dots is set to, for example, 1 (Refresh: rewrite when 1).

The display panel 2 receiving the command line 32 by the digital receiver 21 together with the screen information
In (1), the control circuit 23 recognizes that its own ID is 1 from the contents of (5) the automatic increment ID of the header block 41 sent. Further, since the ID in the command block 42 is 3, it is recognized that the command is not a command for itself, so that data or the like is not fetched, and it operates only as a buffer function using the frame memory 24. Further, (+1) +2 is set to the (5) automatic increment ID of the header block 41 for the next display panel 2 (2) in the chain, and the digital transmitter 22 sends out the command line 32 together with the screen information.

Similarly, the command line 3 together with the screen information
In the display panel 2 (2) which has received 2 by the digital receiver 21, the control circuit 23 recognizes that its own ID is 2 based on the contents of the (5) automatic increment ID of the header block 41 sent. I do. Further, since the ID in the command block 42 is 3, it is recognized that the command is not a command for itself, so that data or the like is not fetched, and it operates only as a buffer function using the frame memory 24. Further, (+1) +3 is set to the (5) automatic increment ID of the header block 41 for the next display panel 2 (3) (not shown), and the digital transmitter 22 sends the command line 32 together with the screen information.
Is sent.

Next, the command line 32 together with the screen information is displayed.
Is received by the digital receiver 21, the display circuit 2 (3) receives, in the control circuit 23, the content of the (5) automatic increase ID of the header block 41 sent.
It recognizes that its own ID is 3. In addition, since the ID in the command block 42 is 3, it is recognized that the command is for itself, and refreshing, that is, taking in of data and the like is performed according to the content of the command. The display is executed by the display circuit 26. Of course, it also operates as a buffer function. Further, +1 is added to the (5) automatic increment ID of the header block 41 for the next display panel 2 (4) not shown, which is linked, and the digital transmitter 2
2 sends a command line 32 together with the screen information.

On the display panel 2 (4), the content of the header block 41 sent thereto is checked, and
, And + for the next panel
Set 5 which is set to 1 and send it out. Further, since the ID in the command block 42 is 3, it is recognized that the command is not a command for itself, and it operates only as a buffer function without taking in data or the like. As described above, the control in the MDA format is performed on the chained display panels 2 (1) to 2 (n) by the flow of the ID as described above.

FIG. 6 shows an enlarged display application using the MDA format in the present embodiment. In FIG. 6, reference numeral 51 denotes a video card, which is a driving program using a so-called MDA format in which video driver software is modified so as to add display timing not used for displaying one line at the end of an original display screen. Is stored in the storage device, and is inserted into a PC to function as a driving device of the display panel. 52
Is a display panel displaying screen information by a single panel. Reference numeral 53 denotes a first display panel group, which enables enlarged display by four display panels. The display panels 53 (1) constituting the first display panel group 53 are connected in a chain to the display panel 52. ing. Reference numeral 54 denotes a second display panel group, which enables enlarged display by nine display panels, and the display panels 54 (1) constituting the second display panel group 54
Are cascaded to the display panel 53 (4) forming the first display panel group 53.

Further, in the present embodiment, the first display panel group 53 and the second display panel group 5
4 are formed of the same XGA (1024 × 76) as the display panel 52.
8) It has a resolution. Furthermore, the display panel 5
2, the first display panel group 53 and the second display panel group 54 are respectively connected in a chain, and the plurality of display panels constituting each display panel group are also in a chain connection in the present embodiment.

As shown in FIG. 6, the same screen information is transmitted to all display panels on the buses connected in a chain. At that time, the input screen information is output as it is on the display panel 52, but on each display panel constituting the first display panel group 53, the screen information is divided into quarters and held in each frame memory. A large screen is configured by enlarging and displaying the held screen information. Similarly, in each of the display panels constituting the second display panel group 54, the screen information is divided into 1/9, held in each frame memory, and the held screen information is enlarged and displayed to form a large screen. I have. Since the operation of each of these frame memories is controlled based on the command information described in the above-mentioned MDA format, it is possible to use a simple configuration without changing the hardware or increasing the number of interface lines. Enlarged display using a plurality of display panels can be performed.

Embodiment 2 In Embodiment 1, the XGA display resolution is set as shown in FIG.
In the display area 31 composed of (1024 × 768), the command line 32 was formed on the 769th line next to the 768th line. In the present embodiment,
Commands are inserted using blanking for each line. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

In this embodiment, as shown in FIG. 7, a command area 61 is provided outside the display time existing in the scanning direction of the formed display area 31, and the display area of the display panel which is cascade-connected to the command area is provided. A control command has been inserted. Specifically, as shown in FIG. 8, n-line screen information 62 formed by 1024 dots
A blanking 64, which is a blank area of 320 dots, exists between the image data 63 and the (n + 1) th line screen information 63. By writing a control command 65 into the blanking 64, the blanking 64 is similar to the command line in the first embodiment. It is possible to add control command information to the screen information. The contents of the control command 65 form a header block 41 and a command block 42 similar to the first embodiment using a plurality of blankings formed between the lines. An MDA format for implementing a chain connection can be developed.

As described above, according to the present embodiment (1 and 2), it is not necessary to construct new hardware when connecting a plurality of display devices (display panels) to the PC device. By transmitting command information to the displayed display panel, it is possible to execute a display operation on an arbitrary display panel. Furthermore, enlarged display using a large number of continuously connected display panels can be easily performed by a simple software change. Furthermore, since each display panel has a function of retaining screen information, there is no need to retransmit the screen information as long as the image is the same. Therefore, the data values on the chained buses do not have a change point, and do not have a change point except when updating the screen information, so that occurrence of EMI (electromagnetic interference) can be suppressed beforehand. It becomes possible.

Further, in the present embodiment (1 and 2), the explanation has been made using the LCD as the display device. When a large screen is generated by a chain connection, the LCD is excellent in that connection for each screen is easy.
The present invention is not limited to D, but can be applied to other electronic displays including light-emitting displays such as CRTs. Further, in the present embodiment, the MDA format is used as one example, and the header block and the command block have been clearly described. However, the present invention does not necessarily need to be clearly separated. Needless to say, it is a matter that should be arbitrarily selected if it has these contents as functions.

[0049]

As described above, according to the present invention,
In a state where physical restrictions from each device are removed, it is possible to chain and connect more display devices, thereby facilitating expansion.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a chain display system according to the present embodiment.

FIG. 2 is an explanatory diagram showing a relationship between screen information and a control command according to the first embodiment.

FIG. 3 is an explanatory diagram showing a format of a command line according to the first embodiment.

FIG. 4 is an explanatory diagram showing an example of data insertion in a header block.

FIG. 5 is an explanatory diagram showing an example of command insertion in a command block.

FIG. 6 is an explanatory diagram showing an enlarged display application using the MDA format in the present embodiment.

FIG. 7 is an explanatory diagram showing a relationship between screen information and a control command according to the second embodiment.

FIG. 8 is an explanatory diagram showing a command insertion timing according to the second embodiment.

[Explanation of symbols]

1. Personal computer (PC), 2 (1) to 2 (n) ...
Display panel, 11 CPU, 12 input / output circuit, 13 RAM, 14 ROM, 15 display control circuit, 21 digital receiver, 22 digital transmitter, 2
3 Control circuit, 24 Frame memory, 25 Liquid crystal display control circuit, 26 Liquid crystal display circuit, 31 Display area, 32 Command line, 41 Header block, 42 Command block, 51 Video card, 5
2 display panel, 53 first display panel group, 54 second display panel group, 61 command area, 62 n-line screen information, 63 n + 1-line screen information, 64 blanking, 65 control commands

Continued on the front page (72) Inventor Toshiya Minami 1623-14 Shimotsuruma, Yamato-shi, Kanagawa Japan Inside the Yamato Office of IBM Japan, Ltd. (72) Inventor Hiroyuki Ikegami 1623-14 Shimotsuruma, Yamato-shi, Kanagawa Japan Inside the Yamato Office of IBM Corporation (72) Inventor Masayuki Hayata 1623-14 Shimotsuruma, Yamato City, Kanagawa Prefecture CA33 CB01 DA87 MM05

Claims (16)

[Claims] 1. A driving method for driving a plurality of display devices to be chained, wherein a display timing not displayed in a display area of the display device is added to a display timing to be visualized in a display area of the display device. A control command for controlling the display device is written with respect to the added display timing, and the control command includes selection information indicating which display device is to be selected from the plurality of chained display devices, and the selected command. A method for driving a display device, comprising control information of the display device. 2. The display timing which is not displayed in a display area of the display device is at least one display timing formed after a last line in the display area.
The method according to claim 1, wherein the timing is for forming a line. 3. The control command is configured by a command line including a header block portion and a command block portion, and the header block portion is a block including header information required for chaining display devices. The method for driving a display device according to claim 1 or 2, wherein: 4. The same screen information is sent to a plurality of display devices for forming a large screen by enlarged display, and the selection information is a plurality of display devices for forming a large screen by enlarged display. 2. The drive of the display device according to claim 1, wherein the control information includes displaying the screen information individually and enlarging the display information on the display device forming a large screen. 3. Method. 5. A driving method for driving a plurality of display devices to be chained, wherein a display timing not displayed in the display area is added to a display timing for visualizing the display area in the display device, A control command for controlling the display device is written with respect to the added display timing, and the control command includes ID information updated each time the display device passes through a plurality of display devices to be chained. A method for driving a display device. 6. The display device according to claim 1, wherein the display device recognizes its own ID based on the ID information and executes a display operation based on instruction information of an ID to be displayed, which is included in the control command. The method for driving a display device according to claim 5, wherein: 7. A driving device for driving a plurality of display devices to be chained, comprising: a video signal generating means for generating a video signal for displaying a video on a display area of the display device; Chain display signal generating means for generating a chain display signal using display timing not used for video display of the display area based on a video signal; and generating the video signal by the chain display signal generated by the chain display signal generation means. Output means for adding to the video signal generated by the means and outputting the chained display signal to any of the chained display devices. 8. A chain display signal generated by the chain display signal generation means is a chain display signal using timing of at least one line not used for video display of the display area based on the generated video signal. The driving device for a display device according to claim 7, wherein: 9. A chain display signal generated by the chain display signal generation means controls selection information of which display device is to be selected from a plurality of display devices to be chained, and controls the selected display device. The drive device for a display device according to claim 7, further comprising control information. 10. A chain display signal generated by said chain display signal generation means includes selection information for selecting all of a plurality of display devices to be chained, and includes the same video signal generated by said video signal generation means. 8. The driving device for a display device according to claim 7, wherein the transmission is performed in a chain to all of the plurality of display devices to be chained. 11. The chain display signal causes the plurality of display devices to divide the video signal individually,
11. The driving device for a display device according to claim 10, further comprising control information for enlarging and displaying the divided video signal on each display device. 12. A display device that can be connected in a chained state to a display drive device that outputs a video signal to be displayed on the chained display devices and a control command for controlling the chained display devices. A digital receiver that inputs the video signal output from the display driving device and a control command added to the video signal and formed at a display timing that is not displayed, and the control command input by the digital receiver. Control circuit for analyzing the video signal, a frame memory for storing the video signal, and a digital transmitter for outputting the video signal and a control command added to the video signal to a connected display device. A display device characterized by the above-mentioned. 13. The control command includes ID information that is updated each time the display device passes through a chained display device, and the control circuit controls the ID information included in the control command input by the digital receiver. The display device according to claim 12, wherein the digital transmitter outputs the ID information updated by the control circuit to a next connected display device. 14. The control circuit according to claim 1, wherein said ID is updated.
14. The display device according to claim 13, further comprising recognizing the own ID based on the information, and comparing the recognized own ID with ID instruction information included in the control command. 15. The control circuit determines whether to display the video signal on its own display device based on the analyzed control command, and the digital transmitter displays the video signal provided by the control circuit. 13. The display device according to claim 12, wherein the display device outputs the video signal and the control command to the next connected display device regardless of whether or not to perform the determination. 16. A display driving device for outputting a video signal to be displayed on a display area and a chain display signal added to the video signal and using at least one line timing not used for the video display. It is possible to input the video signal and the chain display signal while being connected to the display driving device, analyze the chain display signal, and display an image on its own display area based on the video signal. A first display device that is connected to the first display device, and a video signal that is displayed on a display area and is displayed on the display area, and a timing of at least one line that is added to the video signal and is not used for video display. Inputting the used chain display signal and analyzing the chain display signal, and displaying an image on its own display area based on the video signal. Chain display system characterized by comprising a second display device according to ability, the.