JPH11231994A - Display device and controlling method for acquiring information related to display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of executing display suited to the device itself by executing display data channel(DDC) communication and acquiring correct extended display identification data(EDID) when the EDID information of a flat panel display is required. SOLUTION: The EDID information of the flat panel display 17 is stored in the display 17 itself or a display controller 16. When the EDID information of the display 17 is required and an OS outputs a request for the EDID information to the controller 16, the controller 16 switches a DDC interface to a register for storing the EDID information of the display 17 through a DDC interface selection control circuit 18 and acquires the EDID information of the display 17. Consequently the emulation of a basic input/output system(BIOS) can be omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly to acquisition of control information for a flat panel display.

[0002]

2. Description of the Related Art In a computer system such as a personal computer, displaying an image on a display requires information such as the resolution of the display.
The display-specific information such as the display resolution and the manufacturer name is stored in EDID (Extend).
ed Display Identification
Data) information. Also, the communication method for acquiring EDID information from the display is DDC (Disp.
layer Data Channel) communication, and DD
The interface for C communication is called a DDC interface.

[0003] For EDID information and DDC communication, VESA (Video Electronics) is used.
Standards Association) has a standard (“DISPLAY DATA CHANNEL S”).
TANDARD ”Version 1.0 Rev
issue 1.0, 1995)
The technical content is disclosed therein. With this communication method,
The computer system can obtain the EDID information from the display.

[0004] In the case of a flat panel display mainly used in a notebook computer, the flat panel display itself did not hold EDID information because it was not originally assumed that the flat panel display was removed. When the EDID information on the flat panel display is needed to display on the flat panel display, the OS does not actually perform DDC communication with the flat panel display,
BIOS (Basic Input Output S)
(system), the EDID information previously held inside the system was read. Such a method is disclosed in Japanese Patent Application Laid-Open No. Hei 8-2412.
No. 61 discloses it.

Conventionally, how a computer system obtains this EDID information is shown in FIG.
This will be described below with reference to FIG. FIG. 6 is a block diagram of a notebook computer, which is one of the conventional computer systems. Reference numeral 61 denotes a CPU for performing calculations and the like. A main memory 62 is used by the OS and applications. Reference numeral 63 denotes a BIOS which stores EDID information for a flat panel display.
Reference numeral 64 denotes a CMOS memory, which holds information on what display is currently displaying and is referred to when the display is switched. An HDD (Hard Disk Drive) 65 stores an OS and applications. A display controller 66 controls display on a display device. Reference numeral 67 denotes a flat panel display provided as a display device in the notebook computer. As described above, the flat panel display 67 itself does not hold EDID information, and the EDID information of the flat panel display 67 is BIO
It is stored in S63. 68 is a CR used as an optional display in this notebook computer.
T. This CRT 68 is a type of memory EEP
A built-in ROM holds its own EDID information in a built-in EEPROM. Display controller 66 and C
The dotted line connecting to the RT 68 represents the DDC interface.

The acquisition of EDID information of a conventional flat panel display will be described below with reference to a flowchart of FIG. One of the situations where EDID information is required is when the system is started. This will be described as an example. At the time of system startup, BIOS6
3 determines the type of display used at the time of startup. Note that several types of display determination methods have already been put to practical use, and the methods are not specified. The information on the display at the time of startup may be stored in the BIOS 63 in advance, or the type of display may be set by a user's key input or the like at the time of startup. BI
OS63 uses CMO to determine what display to use.
It is stored in the S memory 64 (step 71). Then OS
Reads the type of display from the CMOS memory 64 (step 72). The next display to use is CR
It is determined whether it is T68 (step 73). CR
If it is determined that T68 is to be used, the OS requests the display controller 66 for EDID information of the CRT 68. The display controller 66 performs DDC communication with the CRT 68,
The EDID information is read from the EEPROM built in the RT 68 (Yes in Step 73 to Step 74).
When it is determined that the display to be used is not the CRT 68, the flat panel display 67 is used as the display device. In this case, the OS uses the EDI
D information is read (No from Step 73 to Step 7)
5). Whether the display is a CRT 68 or a flat panel display 67, the OS performs display based on the acquired EDID information (step 76).

[0007] In this system, since the BIOS emulates the EDID information, the capacity increases. In addition, the burden on the BIOS is large. In order to display correctly, it is necessary to change the EDID information in the BIOS every time the type of the flat panel display to be mounted is changed, but this takes time and effort.

[0008]

According to the above-described prior art, information prepared in advance in the BIOS is read in order to obtain EDID information of the flat panel display, so that the capacity of the BIOS increases and the load on the BIOS also increases. There was a problem.

On the other hand, in the CRT, it is a standard technology in the world to acquire EDID information by DDC communication and to perform display suitable for a display. Flat panel display is not emulation in BIOS,
It is important to return EDID information via the DDC interface to ensure compatibility with the CRT.

Therefore, the present invention has been made to solve the above-mentioned problem. Instead of emulating by BIOS, EDID information is held in a flat panel display or a display controller, and the EDID information of the flat panel display is required. When it becomes, D
An object is to provide a device that performs DC communication, acquires correct EDID information, and performs display suitable for a display.

[0011]

SUMMARY OF THE INVENTION The present invention provides a flat panel display, means for storing information about the flat panel display, a communication interface circuit for acquiring information about the flat panel display, and the communication interface. Through the circuit,
Means for acquiring information on the flat panel display. According to such a configuration, when EDID information is required, by performing DDC communication and acquiring correct EDID information, a display suitable for a display can be performed. Also, BI
Since emulation of OS can be eliminated, B
It is possible to reduce the capacity of the IOS and reduce the load on the BIOS.

Further, the present invention is characterized by comprising a flat panel display, an apparatus for controlling the flat panel display, and a circuit for holding information on the flat panel display. According to such a configuration, when EDID information is needed, DD
By performing C communication and acquiring correct EDID information,
Display suitable for the display can be performed.

Further, the present invention is characterized by comprising a step of determining a display to be displayed and a step of switching a communication interface to a storage unit for storing information of the determined display. According to such a configuration, when EDID information is needed,
By performing DDC communication and acquiring correct EDID information, a display suitable for a display can be performed. Further, since the emulation of the BIOS can be eliminated, the capacity of the BIOS can be reduced, and the burden on the BIOS can be reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Regarding the first embodiment, FIG.
This will be described below with reference to FIG. 11 is a CPU. Reference numeral 12 denotes a main memory. Reference numeral 13 denotes a BIOS.
14 is a CMOS memory. Reference numeral 15 denotes an HDD. 1
Reference numeral 6 denotes a display controller. Reference numeral 17 denotes a flat panel display, which in this embodiment incorporates EDID information. Examples of the built-in method include a means such as an EEPROM, but the method is not limited to this. 18
Is a DDC interface selection control circuit, which is a device for connecting the DDC interface to a display performing DDC communication from among a plurality of displays. 19
Is a CRT. Unless otherwise stated, each function is the same as that described in the section of the prior art. For example,
Although not shown, the CRT 19 has a built-in EEPROM. Dotted lines represent the DDC interface as in FIG.

The operation of the apparatus according to the first embodiment will be described with reference to FIG. 2 by taking a system start-up as an example in the same manner as the related art. At system startup, the BIOS 13 determines the type of display to be used at startup. This may be stored in the BIOS 13 in advance, or the type of display may be set by a user's key input or the like at startup.
The BIOS 13 determines which display to use by C
It is stored in the MOS memory 14 (step 21). CM
After storing the type of display to be used in the OS memory 14, the BIOS 13 restarts the system, and
The type of display is read from the S memory 14 (step 22). In accordance with the type of display stored in the CMOS memory 14, the BIOS 13 instructs the DDC interface selection control circuit 18 to connect an interface to the display to be used (step 23). Subsequently, the display controller 16 performs DDC communication with the display connected by the DDC interface selection control circuit 18 and reads out the EDID information (step 24). This reading is performed through the DDC interface. The OS performs a display suitable for the display, such as determining the resolution based on the read EDID information (step 25).

Although the system startup has been described as an example, after the system starts up, in a system in which a display can be switched by a specific key operation or a specific multiple key simultaneous depressing, that is, a hot key input, a hot switch is used. After receiving a key input, EDID information can be acquired and displayed according to the flowchart of FIG. In the case of switching by hot key input, switching is performed without restarting the system during system setup.

According to this embodiment, the OS is also pseudo-ED from the BIOS for the flat panel display.
Instead of reading the ID information, the correct ED of the flat panel display connected by DDC communication
ID information can be obtained. As a result, BIOS
And the load on the BIOS can be reduced.

The second embodiment will be described as follows with reference to FIG. 301 is a CPU. 302
Is the main memory. 303 is a BIOS. Reference numeral 304 denotes a CMOS memory. Reference numeral 305 denotes an HDD. 306
Is a display controller. A flat panel display 307 does not hold EDID information as in the related art. A register 308 holds EDID information of the flat panel display 307. The flat panel display 307 and the register 308 are provided in the form of a flat panel display module 309, and are connected to the display controller 306 and a DDC interface selection control circuit 310 described later. 310 is DD
This is a C interface selection control circuit. 311 is a CRT
It is. The function of each device is the same as that of the corresponding device in the first embodiment unless otherwise specified. OS
Is the same as that of the first embodiment for reading the register in order to obtain the EDID information. The point that the register can be handled separately from the flat panel display is different from the first embodiment in which the flat panel display has a built-in register.

Also in the second embodiment, the OS is a BIO
EDID of flat panel display from S
Instead of reading the information, the correct EDID information of the connected flat panel display can be obtained by DDC communication. Further, in this embodiment, the ED
The device that holds the ID information is a DD
The register 308 connected to the C interface selection control circuit 310 is realized in the form of a module. In this way, even for a display that does not internally hold the EDID information as in the related art, a module of the register 308 storing the EDID information of the display device is provided later and connected to the DDC interface selection control circuit 310. By doing so, E of the display device by DDC communication
DID information can be obtained, and display suitable for a display can be performed. Further, the capacity of the BIOS can be reduced, and the burden on the BIOS can be reduced.

In the illustration of the present invention, the DDC interface selection control circuit is shown separately from the display controller. However, it is of course possible to incorporate the DDC interface selection control circuit in the display controller.

The first and second embodiments also provide a flat panel display to be used when a user intends to make a notebook personal computer, and an E-data stored in the BIOS.
There is an advantage that it is not necessary to consider the possibility that the DID information does not correspond.

The third embodiment will be described below with reference to FIGS. FIG. 4 is a block diagram of a computer system for implementing the present embodiment. The configuration is the same as that described in the section of the second embodiment except that the DDC interface selection control circuit 409 and the EDID information storage register 408 are incorporated in the display controller 406. The EDID information storage register 408
It is also possible to divert and use a part of a VRAM (not shown). The third embodiment is based on the prior art BIO
S emulated EDID information,
The emulation is performed by the display controller 406. When the system is started, BIOS 403 is CMOS
The type of display to be used is read from the memory 404, and EDID information for the flat panel display 407 is set in the EDID information storage register 408 inside the display controller 406. This will be described below with reference to the flowchart of FIG.

When the system is started, the BIOS 403
Determines the type of display to be used at startup. This is similar to the first embodiment in that the BIOS 40
3 may be stored, or the type of display may be set by a user's key input or the like at startup. The BIOS 403 stores the type of display to be used in the CMOS memory 404 (step 51). After storing the type of display to be used in the CMOS memory 404, the BIOS 403 restarts the system and reads the type of display from the CMOS memory 404 (step 52). Next, BIOS 403
Stores EDID information corresponding to the display in the EDID information storage register 408 (step 53). In step 53, the display controller 406 may store the EDID information in the EDID information storage register 408 instead of the BIOS 403. Next, CM
In accordance with the type of display stored in the OS memory 404, the BIOS 403 instructs the DDC interface selection control circuit 409 to connect an interface to the display to be used (step 54).
Subsequently, the display controller 409 performs DDC communication with the connected EDID information storage register 408 or CRT 410 to read out the EDID information (step 55). This reading is performed through the DDC interface. O
S performs display suitable for the display, such as determining the resolution based on the read EDID information (step 5).
6).

The present embodiment has an advantage that the reaction is quick because there is no need to directly perform DDC communication with the flat panel display. In addition, diverting VRAM to ED
When the ID information storage register is set, the circuit can be simplified. Also in this embodiment, similarly to the other embodiments, the capacity of the BIOS can be reduced, and the burden on the BIOS can be reduced.

[0025]

As described above, according to the present invention,
From the BIOS, a pseudo flat panel display E
Instead of reading out the DID information, it is possible to obtain the EDID information of the flat panel display by DDC communication.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a computer system according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating switching control of a DDC interface control circuit and acquisition of EDID information from a flat panel display according to the first embodiment of the present invention.

FIG. 3 is an exemplary block diagram showing a system configuration of a computer system according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a system configuration of a computer system according to a third embodiment of the present invention.

FIG. 5 is a flowchart illustrating switching control of a DDC interface control circuit and acquisition of EDID information from an EDID information storage register according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a conventional computer system.

FIG. 7 is a flowchart showing acquisition of EDID information in which a conventional BIOS notifies an OS of EDID information of a flat panel display.

[Explanation of symbols]

11 CPU, 12 main memory, 13 BIOS, 14
... CMOS memory, 15 ... HDD, 16 ... Display controller, 17 ... Flat panel display, 18 ... DD
C interface selection control circuit, 19 ... CRT, 301
… CPU, 302… main memory, 303… BIOS, 30
4. CMOS memory, 305 HDD, 306 display controller, 307 flat panel display, 3
08: register, 309: flat panel display module, 310: DDC interface selection control circuit, 311: CRT, 401: CPU, 402: main memory, 403: BIOS, 404: CMOS memory, 40
5 HDD, 406 display controller, 407 flat panel display, 408 EDID information storage register, 409 DDC interface selection control circuit,
410 CRT, 61 CPU, 62 main memory, 63
... BIOS, 64 ... CMOS memory, 65 ... HDD, 6
6 display controller, 67 flat panel display, 68 CRT

Claims (10)

[Claims] A flat panel display; means for storing information about the flat panel display; a communication interface circuit for acquiring information about the flat panel display; and the flat panel display via the communication interface circuit. Means for acquiring information about the display. 2. The display device according to claim 1, wherein the means for storing information on the flat panel display forms a part of the flat panel display. 3. The display device according to claim 1, wherein the means for storing information on the flat panel display forms a part of a module of the flat panel display. 4. A flat panel display according to claim 1, further comprising means for switching said communication interface circuit to said second display when using a second display. The display device according to the above. 5. A display device, comprising: a flat panel display; a device for controlling the flat panel display; and a circuit for holding information on the flat panel display. 6. The display device according to claim 1, further comprising: a communication interface circuit for acquiring information on the flat panel display; and a unit for acquiring information on the flat panel display via the interface circuit. Item 6. The display device according to Item 5. 7. A computer system to which a plurality of displays can be connected, comprising: a step of determining a display to be displayed; and a step of switching a communication interface to storage means for storing information of the determined display. A control method for acquiring display information. 8. The control method for acquiring display information according to claim 7, wherein the step of determining a display to be displayed includes determining a display selected by a user. 9. The method according to claim 1, wherein the step of determining the display to be displayed includes the step of recognizing the determined display, and the switching of the communication interface is performed by a storage unit that stores information on the recognized display. The control method for acquiring information on a display according to claim 7, characterized in that: 10. The display device according to claim 9, further comprising a step of storing information about the display in a storage unit for storing information of the display after the step of determining the display to perform the display. Control method to obtain information.