JP3477397B2 - A driving method, a driving device, a display device capable of being chained, and a chained display system for a plurality of display devices to be chained. - 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 device using an LCD panel or the like, and more particularly to a drive method for driving a plurality of chained display devices, a drive device, and a chainable display device. , And a chain display system.

[0002]

2. Description of the Related Art In recent years, a technique has been proposed in which a plurality of display panels are connected to a personal computer (PC), a plurality of small display panels are combined and used as a display having a large screen as a whole.
At this time, according to the normal interface specifications, only one display panel is displayed per one video chip. For example, if four display panels are to display different images, four video chips are required. . Therefore, even if many display panels are displayed under a normal interface, only 4 to 8 panels can be connected at maximum due to the restrictions in the space and slots in the PC housing, the number of connections, etc. There was a limit to the expansion of the panel. In addition, 4 video chips can
When displaying different images on one display panel, the CPU in the PC only updates (UPDATE) the memory of one video chip for a certain time. Therefore, during this time, the memory in the remaining three video chips had only the function of holding the screen.

Here, as a conventional technique for connecting a plurality of display devices (monitor devices) to one PC device, there is JP-A-9-319550. In this conventional technique, 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, and each display device has its own store instruction key. Whether to take in the video signal 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, as a conventional technique for connecting a plurality of display devices to one PC, there is JP-A-9-274475. This publication discloses a technique in which ID information is inserted immediately before the video data of the first line for each frame and the video data is fetched only when the ID information matches a preset ID in each display device. . According to this technique, a plurality of display devices can be driven by a single system output from the PC device, and wiring can be simplified.

On the other hand, in recent years, digital interfaces have been introduced mainly in notebook type PCs, and at present, they are used only by connecting the PC and the display in a one-to-one correspondence. For the technology to connect multiple displays in a daisy chain state with this digital interface, see the gigabit video interface by Sony Corporation.
(GVIF) application note. In the future, it is expected that the number of modes in which the digital interfaces are connected and used in a chained state will increase more and more.

[0005]

However, in the technique described in Japanese Patent Laid-Open No. 9-319550, since the display devices are connected in parallel, an interface is provided between the PC device and the display device. The wiring becomes complicated. Further, a store signal detection circuit must be provided for each display device, which also complicates the hardware configuration. Further, in the technique described in Japanese Patent Laid-Open No. 9-274475, it is necessary to provide an ID setting circuit for each display device, and it is necessary to set an ID every time the number of display devices is changed. The work in the device becomes complicated. Further, in this publication, only the disclosure of collation of ID information is merely disclosed, and it is not possible to perform different control for each display device by the PC device.

Furthermore, in order to achieve the above 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 that display device to a chained display device, only the technology presented here is used. Then, it is necessary to send these information separately from the video signal. In such a case, not only software changes,
It is necessary to change the hardware and increase the number of interface lines.

The present invention has been made in order to solve the above technical problems, and its purpose is to:
It is possible to connect more display devices in a state where physical restrictions from each device are removed, and to facilitate expansion.

Another object is to make it possible to send command information to display devices connected in a chain without changing the hardware on the system side, and more specifically, to video. By rewriting the register in the chip, the command information can be sent and automatically sent without being distinguished from the 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. More specifically, a large number of connected devices in a chain can be used. The screen information is individually displayed on the display device in an enlarged manner based on the command information.

In order to solve the above problems, the present invention provides
A driving method for driving a plurality of chained display devices, wherein a video signal generated at a display timing for visualizing in a display area of the display device is generated at a display timing not displayed in this display area. A video signal is added, and a control command for controlling the display device is written for the video signal generated at the added display timing, and this control command selects which display device from a plurality of chained display devices. It is characterized in that it includes selection information as to whether or not to select and control information of the selected display device.

The video signal generated at the display timing which is not displayed in the display area of this display device may be either the top, bottom, left or right in the display area, but blanking at the end of each line on the right side of the display area is used. According to the method described above or the method of using the predetermined line after the end of the frame corresponding to the lower side of the display area, since the display reference is generally at the left end, it is not necessary to change the display reference in this image display. In particular, it is preferable to use the video signal generated at the display timing of at least one line formed after the last line in this display area because blanking at the end of each line can be reduced.

The control command used here is composed of a command line consisting of a header block part and a command block part, and this header block part is a block containing header information required for chaining the display devices. Characteristically, command information such as how to write screen information to which display device and how to control that display device, etc., by changing software without changing hardware. Is preferable in that it can be transmitted. Further, this header information includes version information of the chain display control software, an automatically increasing ID that increases every time the display device is connected, and the like.

Further, according to this driving method, the same screen information is sent to a plurality of display devices for constructing a large screen by enlarging display, and the selection information is used for constructing a large screen by enlarging display. 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 a display device forming a large screen. Even when displaying, it is preferable because a new update action for one image is unnecessary. In particular, when a liquid crystal display (LCD) is used as a display device, it is excellent in that it is easy to connect each screen when forming a large screen by a plurality of display devices.

Further, the present invention is a driving method for driving a plurality of chained display devices, wherein a video signal generated at a display timing for visualizing in a display area of the display device is displayed in the display area. A video signal generated at a display timing that is not displayed is added, and a control command for controlling a display device is written for the added video signal generated at this display timing. If the display device loses its ID information at the time of initializing power ON / OFF of the device, for example, even if each display device loses its ID information, the ID information is updated every time it passes through the display device. It is preferable in that it can automatically have its own ID by receiving the control command. In particular, if the ID information is configured to be automatically added every time a plurality of linked display devices are passed,
This is effective in that the function can be achieved by simplifying the software.

Further, this display device is configured to recognize its own ID based on the ID information and to execute the display operation based on the instruction information of the ID to perform the display operation included in the control command. This is preferable in that it is possible to freely select each of the chained display devices and execute the display operation without individually setting the ID in each display device.

On the other hand, the present invention is a drive device for driving a plurality of chained display devices, and video signal generating means for generating a video signal for displaying a video image on a display area of the display device. A chained display signal generating means for generating a chained display signal using display timing not used for displaying a video image in this display area based on the generated video signal, and a chained display signal generated by the chained display signal generation means for generating a video signal. The output means adds the video signal generated by the means to the display device and outputs the chained display signal to any of the linked display devices.

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

Further, the chained display signal generated by the chained 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. It is also possible to configure such that the video signals are sent to all of the plurality of display devices in a chained manner. It is preferable to include control information for enlarging and displaying the video signal on each display device in that a plurality of display devices connected in a chain can be collectively formed into a large screen. The drive device according to the present invention can be realized in the form of, for example, an additional board or a video card connected to a connector inside the PC.

Furthermore, the present invention can be connected in a chain state to a display driving device that outputs a video signal for displaying on a chained display device and a control command for controlling the chained display device. And a digital receiver for inputting a video signal output from a display drive device and a control command formed in a video signal generated at a display timing that is added to the video signal and is not displayed, and a digital receiver Control circuit that analyzes the control command input by the receiver, frame memory that stores the video signal, digital transmission that outputs the video signal and the control command added to this video signal to the connected display device It is characterized by having a machine. By providing this frame memory on the display device side, rather than on the system side, which is the display drive device, having a memory for holding screen information, a single display control circuit can display images on multiple display devices. It becomes possible to do.

Further, in this display device, the control circuit determines whether or not to display the video signal on its own display device based on the analyzed control command, and the digital transmitter transmits the video signal made by this control circuit. It is preferable that the video signal and the control command are output to the next connected display device regardless of whether the display is performed or not, because the function as a simple buffer can be achieved. . Here, the control command output from this digital transmitter does not necessarily have to match the control command input by the digital receiver,
For example, the contents may be partially different such as added ID information. Similarly, the video signals do not necessarily have to match, but if the video signals are output to another display device as they are, it is not necessary to perform the video signal changing process.

Further, the chained display system according to the present invention is a chained video signal generated in a display area and a chained display timing of at least one line which is added to the video signal and is not used for video display. A display drive device that outputs a display signal, and a video signal and a chain display signal that are connected to the display drive device are input, and the chain display signal is analyzed, and based on this video signal, a display area of its own is displayed. A first display device capable of displaying an image on the other hand, and a video signal and a chain display signal which are connected to the first display device are input, and the chain display signal is analyzed. And a second display device capable of displaying an image on its own display area based on the above. Here, the image display on each display device does not necessarily have to be the entire image signal, and may be a partial display. In particular, when a magnified display is performed using four or more display devices, the divided video may be magnified and displayed. In addition, the chain display signal input to the first display device and the chain display signal input to the second display device are
As described above, they do not necessarily have to match, and there is no problem even if they include different information such as added ID information.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment Hereinafter, the present invention will be described in detail based on the embodiments shown in the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a chained display system to which the present invention is applied.
In FIG. 1, reference numeral 1 is a personal computer.
(PC) and has a role as a driving device for driving the display device in this embodiment. In the personal computer 1, reference numeral 12 is an input / output circuit including a keyboard and a mouse, and 13 is an RA including a hard disk or an IC or the like in which data such as a video signal is stored.
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 be a video signal generated by an external device. Reference numeral 11 denotes a CPU, which executes the execution processing of the personal computer 1 based on a control program from the ROM 14 and a user's instruction from the input / output circuit 12. Further, reference numeral 15 is 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 brightness control. This is a circuit that controls the display device such as whether to generate a command line containing control commands and adds this command line to the video signal (screen information) and outputs it to the display panel described later. .

Further, in FIG. 1, reference numerals 2 (1) to 2 (n)
Is a display panel, and in the present 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)-
In 2 (n), reference numeral 21 is a digital receiver for receiving a video signal (screen information) and a chain display signal (control command), and 22 is a digital receiver for outputting the screen information and control command to a connected display panel. It is a 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
Digital transmitter 2 on display panel 2 (1) of
Received output from 2. 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 transmitters / receivers enable a chained state as a system.

Reference numeral 23 is 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 24 is received by the digital receiver 21. A frame memory for storing screen information, a liquid crystal display control circuit 25 for sequentially extracting information for one screen stored in the frame memory 24 and controlling a liquid crystal display circuit 26 described later, 26
Is controlled by the liquid crystal display control circuit 25,
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.
It is explanatory drawing which shows the relationship of the screen information and control command transmitted with respect to 2 (n). In this embodiment, the command line 32, which is a control command, is sent after the last line of the display area 31 that is 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 x 768
aphics Array), 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 769th line, which is next to the 768 line, is formed. In the command line 32, as described above, the display panels 2 (1) to 2 (n) to which the screen information should be written
And a control command indicating how to control the selected display panel are formed. Upon receiving the screen information of the display area 31 and the control command formed on the command line 32, the display panels 2 (1) to 2 (n) analyze the control command and display the presence / absence of the display on its own panel. I have decided how.

FIG. 3 shows the format of the command line in this embodiment. The command line in the present embodiment has two parts, a header block 41 and a command block 42, which are roughly divided in a video signal generated at one display timing. This header block 41 is used for the total number of commands (CHECKS) used for version information and noise check.
UM), automatic increase ID, and so on, which corresponds to so-called header information, and has a fixed length in the present embodiment. On the other hand, the command block 42 is composed of a set of 2 dots and expresses one command in units of 2 dots. This first dot is the ID number that executes the command,
The command number, whether the command is unique, whether the ID command is valid (enable state), and other commands are included. The next second dot stores the data value corresponding to the first dot command. There is. If the beginning of the command line is the 0th dot, even-numbered dots in the command block 42 are arranged with the command corresponding to this 1st dot, and odd-numbered dots are arranged with their values corresponding to the 2nd 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). In the present embodiment, LS is used.
B2 bit is reserved. Also, since there are three data of red (R), green (G), and blue (B) for each dot of the display, a maximum of 6 can be set for one dot.
It is possible to express the command information for each dot using 18 bits of × 3. Furthermore, in the present embodiment,
The 0 to 15th dot of the command line is the header block 41, and the 16th and subsequent dots are the command block 4
2 In addition, unused portions of both blocks are reserved. In the present embodiment, different display screens can be displayed on a plurality of display panels by the interface using this command line, and the format based on these concepts can be changed to MDA (Multipl).
e Display Architecture).

Here, the header block 41 in this embodiment is composed of the following items. (1) Name (MDA id with MDA on valid) (1 dot) (2) Version information (Version) (1 dot) (3) Horizontal resolution (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) MDA command total number (Command line total number) (1
(Dot) (8) MDA command total number (Check sum of MDA line) (1 dot) (9) Test mode enable / disable (Test mode enable) (1 dot) (10) Reserve (7 dots)

The first dot (1) name of the header block 41 is an indication that this format is MDA, and is used to confirm whether the MDA command 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 display a resolution of 1024 × 768 in this embodiment. Further, (5) the automatically increasing ID is displayed on the display panels 2 (1) to
It is a value that automatically increases every time 2 (n) is passed, and each display panel can automatically have its own ID without having to be specially set. This automatic increase ID
Therefore, even if you lose your ID information at the time of initializing when turning the power off / on, for example, MD
By receiving A format, I
It becomes possible to recognize D.

Further, (6) MDA command line valid / invalid instruction is used for protection while updating the MDA command line and the like, and data on digital signals connected in a chain are parallel. When the data is converted from serial to serial, error transfer of data due to delay in tracking is prevented, and the information has automatic time limitation. next
(7) The total number of MDA commands is used to increase the number of MDA command lines, and the number of MDA command lines is not limited to one line as in the present embodiment, and the number of lines is increased to increase chain command information. Can be sent. In addition, (8) MDA command total number is a check to see if the information is correct, and whether the command line is garbled due to noise. Since it is easy, this embodiment is particularly effective. Regarding the following (9) test mode valid / invalid, a test item can be inserted by setting this bit, and it can be used, for example, for confirmation of connection. 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 made up of the above items contains values as shown in FIG. 4, for example. The 0 dot on the left side of FIG. 4 has R as the above (1) name.
The names of M (2Dh), D (24h) and A (21h) are entered using the upper 2 bits (2 bits from the most significant bit (MSB)) and the lower 4 bits of the data, G data and B data. ing. Further, in the next one dot on the right side in FIG. 4, version information using R, G, B data as the above (2) version information is entered.

Next, the command block 42 in this 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 saving mode-Backlight off
and LCD logic off) (6) Screen information retention and screen information update (Freeze and Refres
h) (7) Display enable / disable (blue when disabled) (Display disable / enabl
e, blue back) (8) Expansion ratio (horizontal / vertical) (Expansion ratio (H / V)) (9) to (12) Input data acquisition start position and end position
(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 SVGA are displayed on UXGA (Four SVGA to
UXGA)

The first item of the command block 42, (1) brightness control and (2) contrast control, adjusts and controls the brightness and contrast of the display panels 2 (1) to 2 (n) which perform a display operation. (3) Gamma control is L according to the γ correction curve for input / output adjustment.
It is for giving a reference voltage to the CD. Further, (4) white adjustment is a white point adjustment value that determines a tint level, and (5) power saving mode is an item related to power saving mode settings such as backlight turning off and LCD circuit power supply cutoff. Also, (6) Screen information retention and screen information update indicate the time when MDA command is not accepted even if given, and (7) Display valid / invalid (blue when invalid) is appropriate by itself when an improper signal is received. It is a command to select to output black or blue. (8) Enlargement display ratio shows the enlargement ratio in the horizontal and vertical directions. Further, (9) to (12) input data fetching start position and end position are registers for setting which portion of the data sent from the display device is to be fetched, and (13) to (16). The display start (end) position on the LCD is a register that sets up to where the captured data is displayed on the LCD. In addition, (17) extra frame part, valid / invalid is VGA (Video g
resolution such as raphics Array) (640 x 480) is XGA
This is a register for setting whether or not to color the remaining portion when displaying (1024 × 768). Furthermore,
(18) Displaying four SVGAs on UXGA is SVGA (s
input data of upr VGA) (800 x 600) and UXGA (1
This is a register used when displaying (600 × 1200).

FIG. 5 shows an example of command insertion in the command block 42. In this embodiment, two dots form one command as shown in FIG.
The first dot (2n dot) represents the command, the next dot
(2n + 1 dot) describes the parameter. In the example of FIG. 5, the first bit from the MSB of the R data indicates whether or not the command is valid (Valid or Invalid), and the next bit indicates the command in each display panel 2
In (1) to 2 (n), is it common or is it unique to each display panel (Common or Uniqu)
e) is shown. Command of this bit (Common or Uni
que) is a command effective when displaying and outputting the same image on each of the plurality of display panels 2 (1) to 2 (n). Next, the lower bit and the G data are used to identify
A command is formed, and a maximum of 256 display panels can be selected by 8 bits of ID7 to ID0. The 6th bit from the MSB in the next B data indicates where in the display register the data is given.
The internal register addresses in the control circuit 23 of the display panels 2 (1) to 2 (n) shown in FIG.

In the next dot of 2n + 1 dots shown in FIG. 5, the value corresponding to the command of 2n dots is stored. That is, in the display panel having the ID designated by 2n dots, the data indicating what is to be executed is described for the designated internal register address, and the upper rank in each data of R, G, B is described. All 6 bits are used and the actual display is performed on the display panels 2 (1) to 2 (n) based on the data of 2n + 1 dots. 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 these 2n and 2n + 1 dots are used as the start position at the display position on the LCD. ing.

The flow of displaying screen information on the display panel of No. 3, for example, using the MDA format adopting the header block 41 and the command block 42 in the command line 32 as described above is mainly shown in FIG. This will be described using 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, the ID of the 2n dot command in the command block 42 is set to 3, and A5 to A0 is set to 6 (Freeze and Refresh). The content of the data in 2n + 1 dots is set to, for example, 1 (Refresh when 1 is set).

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

Similarly, the command line 3 together with the screen information is displayed.
In the display panel 2 (2) which received 2 by the digital receiver 21, the control circuit 23 recognizes that its own ID is 2 by the contents of the (5) automatic increment ID of the header block 41 sent. To do. Further, since the ID in the command block 42 is 3, it recognizes that it is not a command for itself, does not fetch data and the like, and operates only as a buffer function using the frame memory 24. Further, for the next display panel 2 (3) not shown in the figure, 3 is added to the (5) automatic increment ID of the header block 41, 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.
In the display panel 2 (3) that received the message from the digital receiver 21, the control circuit 23 causes the contents of the (5) automatic increment ID of the header block 41 sent to
Recognize that your ID is 3. Also, since the ID in the command block 42 is 3, the command is recognized as a command for itself, refresh is performed according to the content of the command, that is, data is fetched, and the liquid crystal display control circuit 25 controls the liquid crystal display. Display is performed by the display circuit 26. Of course, it also works as a buffer function. Further, for the next display panel 2 (4) (not shown) that has been chained, 4 is added to (5) automatic increment ID of the header block 41, and the digital transmitter 2
The command line 32 is sent from 2 together with the screen information.

On the display panel 2 (4), the ID of the user's own ID is 4 when the contents of the header block 41 sent are seen.
And for the next panel +
Set 1 to 5 and send it. Further, since the ID in the command block 42 is 3, the command block 42 recognizes that it is not a command for itself and does not fetch data or the like, and operates only as a buffer function. As described above, the control in the MDA format is executed for the display panels 2 (1) to 2 (n) connected in a chain by the ID flow described above.

FIG. 6 shows an enlarged display application using the MDA format according to this embodiment. In FIG. 6, reference numeral 51 is a video card, which is a so-called M, in which the video driver software is changed so that a video signal generated at a display timing not used for displaying one line is added to the end of the original display screen.
A drive program using the DA format is stored and inserted into a PC to function as a drive device for a display panel. Reference numeral 52 is a display panel which displays screen information by a single panel. Also, 53
Is a first display panel group, and four display panels enable enlarged display, and display panels 53 constituting the first display panel group 53.
(1) is chain-connected to the display panel 52. Reference numeral 54 denotes a second display panel group, which enables enlarged display by nine display panels, and the display panel 54 (1) forming the second display panel group 54 forms the first display panel group 53. The display panel 53 (4) is connected in a chain.

Further, in the present embodiment, the first display panel group 53 and the second display panel group 5
4 are 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 connected in a chain, respectively, and the plurality of display panels forming each display panel group are also in a connected state in the present embodiment.

The same screen information is sent to all display panels on the buses connected in a chain as shown in FIG. At that time, the display panel 52 outputs the inputted screen information as it is, but in each display panel constituting the first display panel group 53, the screen information is divided into 1/4 and held in each frame memory, A large screen is constructed by enlarging and displaying the held screen information. Similarly, in each display panel that constitutes the second display panel group 54, screen information is divided into 1/9 and held in each frame memory, and the held screen information is enlarged to form a large screen. There is. Since the operation of each of these frame memories is controlled based on the command information described in the above-mentioned MDA format, a simple configuration can be used without changing hardware or increasing the number of interface lines. Enlarged display can be performed using a plurality of display panels.

◎ Second Embodiment In the first embodiment, as shown in FIG. 2, XGA display resolution
In the display area 31 composed of (1024 × 768), the command line 32 was formed on the 769th line, which is next to the 768th line. In this embodiment,
The command is inserted using blanking for each line. The same components as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted here.

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 a display panel connected in chain to this command area. A control command is inserted. Specifically, as shown in FIG. 8, n-line screen information 62 formed of 1024 dots is displayed.
The blanking 64, which is a 320-dot blank area, exists between the n + 1 line screen information 63 and the n + 1 line screen information 63. By writing the control command 65 in the blanking 64, the blanking 64 is the same as the command line in the first embodiment. It is possible to add the control command information to the screen information. The content of the control command 65 uses a plurality of blankings formed between the lines to configure a header block 41 and a command block 42 similar to those in the first embodiment, and similar to the first embodiment. The MDA format for implementing the chain connection can be developed.

As described above, according to the present embodiments (1 and 2), it is not necessary to construct new hardware when connecting a plurality of display devices (display panels) to a PC device, and chain connection is possible. By sending the command information to the displayed display panel, the display operation can be executed on any display panel. Furthermore, by simply changing the software, it is possible to easily perform enlarged display using a large number of display panels connected in series. Furthermore, since each display panel has a screen information holding function, it is not necessary to retransmit the screen information as long as it has the same image. Therefore, the data values on the buses connected in a chain do not have a change point and do not have a change point except when updating the screen information, so that the occurrence of EMI (electromagnetic field interference) can be suppressed in advance. It will be possible.

Also, in the present embodiment (1 and 2), an LCD is used as a display device. When a large screen is generated by 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 thereof, and the header block and the command block are clearly separated, but the present invention does not necessarily have to be clearly separated as described above. It is needless to say that it is a matter that should be arbitrarily selected if it has these contents as a function.

[0049]

As described above, according to the present invention,
It is possible to connect a larger number of display devices in a chain in a state where physical restrictions from each device are removed, and it is possible to facilitate expansion.

[Brief description of drawings]

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

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

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

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

[Explanation of Codes] 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 command

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshiya Minami 1623 Shimotsuruma, Yamato-shi, Kanagawa 14 Yamato Works, IBM Japan, Ltd. (72) Hiroyuki Ikegami 1623 Shimotsuruma, Yamato-shi, Kanagawa Address 14 Japan IBM Co., Ltd. Yamato Works (72) Inventor Masayuki Hayata 1623 Shimotsuruma Yamato City, Kanagawa Prefecture 14 IBM Japan Co., Ltd. Yamato Works (56) References 9-274475 (JP, A) JP-A-4-329593 (JP, A) JP-A-11-126047 (JP, A) JP-A-62-163164 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 5/00 510

Claims (4)

(57) [Claims] 1. A driving method for driving a plurality of linked display devices, wherein a video signal generated at a display timing for visualizing the display area of the display device is not displayed in the display area. A video signal generated at display timing is added, and a control command for controlling the display device is written to the added video signal generated at the display timing. A video signal generated at the display timing that is not displayed in the display area of the display device includes selection information indicating which display device is selected from the devices and control information of the selected display device. The image generated at the display timing to visualize the area Formed after the signal line, the display data of the control command is filled out
The video signal generated by the aiming is received by the digital receiver of the chained display device, read into the buffer, and the control circuit transmits the control command to itself.
When it is recognized that the video signal is not received, the received video signal is sent from the digital transmitter to the next display device in the chain, and the control command in the control circuit sends the control signal to itself.
When it is recognized as a command , the display device is driven by the liquid crystal display circuit under the control of the liquid crystal display control circuit. 2. A drive device for driving a plurality of chained display devices, comprising: a video signal generating means for generating a video signal for displaying a video in a display area of the display device; A chained display signal generating means for generating a chained display signal using display timing which is not used for video display of the display area based on the video signal; and the chained display signal generated by the chained display signal generation means for generating the video signal. A chain display signal generated by the chain display signal generation unit, the output unit adding the chain display signal to the display device and outputting the chain display signal to any display device to be chained. Is information for selecting which display device to select from a plurality of display devices to be chained, and a control for controlling the selected display device. And a chained display signal generated by the chained display signal generating means is formed after a line of the video signal that is video-displayed in the display area of the display device, and the chained display signal is added. In the video signal generating means
The video signal generated by the above is received by the digital receiver of the display device to be chained, read into the buffer, and the chained display signal is displayed to the self in the control circuit.
If it is recognized that the video signal is not a signal , the received video signal is sent from the digital transmitter to the next display device in the chain, and the chained display signal is transmitted to itself in the control circuit.
When it is recognized as a display signal , the liquid crystal display circuit executes display under the control of the liquid crystal display control circuit. 3. A display device which is connectable in a chain state to a display drive device which outputs a video signal for displaying on the chained display device and a control command for controlling the chained display device. A digital receiver for receiving the video signal output from the display drive device and a control command formed in the video signal generated at display timing that is added to the video signal and is not displayed; A control circuit that analyzes the received control command, a frame memory that stores the video signal, and a digital transmission that outputs the video signal and the control command added to the video signal to a connected display device. And a control command is added after the line of the video signal to be displayed on the display device to be chained. Is not formed on the video signal generated by the display timing, the display Thailand Mi said control command is added
The video signal generated by the ringing is received by the digital receiver of the chained display device, read into the buffer, and the control command causes the control command to be transmitted to itself.
When it is recognized that the video signal is not received, the received video signal is sent from the digital transmitter to the next display device in the chain, and the control command in the control circuit sends the control signal to itself.
When the command is recognized, the display is executed by the liquid crystal display circuit under the control of the liquid crystal display control circuit. 4. A display drive device for outputting a video signal which is video-displayed in a display area and a chained display signal which is added to the video signal and is generated at a display timing not used for video display, It is possible to connect to a display driving device to receive the video signal and the chained display signal, analyze the chained display signal, and display a video on its own display area based on the video signal. A first display device, a video signal connected to the first display device, which is video-displayed in a display area, and a chained display generated at a display timing which is added to the video signal and is not used for video display It is possible to receive the signal and analyze the chained display signal and display an image on its own display area based on the image signal. And a second display device, the chain display signal, the formed after the line of the video signal displayed image relative to the display area, the video signal in which the chain display signal is added, the first
1 is received by the digital receiver of the display device , read into the buffer, and the chained display signal is chained to itself in the control circuit.
If it is recognized that the video signal is not a display signal , the received video signal is sent from the digital transmitter to the second display device connected to the first display device, and the chained display signal is sent by the control circuit. For myself
A chain display system in which display is executed by the liquid crystal display circuit under the control of the liquid crystal display control circuit when it is recognized as a chain display signal .