JPH11272250A - Computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a notebook type personal computer which can use an external flat panel display carrying a digital interface. SOLUTION: A digital interface connector 33 to which an external flat panel display monitor 41 can be connected and an analog RGB connector 32 to which an external analog CRT monitor 42 can be connected are provided on the computer main body 100 of a notebook type personal computer, and the external flat panel display monitor 41, the external analog CRT monitor 42, and a built-in flat panel display monitor 31 are controlled by the same display controller 13. Therefore, display control matching a service environment, as for simultaneous display on the built-in flat panel display monitor 31, the external flat panel display monitor 41, and the external analog CRT monitor 42 and their selective display, can be performed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a computer system such as a personal computer (hereinafter, referred to as a PC), and more particularly to a computer system improved to control various display monitors.

[0002]

2. Description of the Related Art In a conventional notebook PC, laptop PC, and desktop PC, an analog interface (R, B, and G are analog data) is mainly used as an external monitor interface. Therefore, when giving a presentation on a notebook PC, the analog C
Using an RT monitor, the analog CRT monitor and a built-in flat panel display are simultaneously displayed.

[0003] Recently, the environment in which a flat panel display is externally used as a monitor has been increasing due to a reduction in the price of a flat panel such as an LCD. Such an external flat panel display monitor is originally driven and controlled by a digital display signal, like the built-in flat panel display, but recently, by providing an analog / digital conversion function inside, A configuration that can be connected to an analog RGB connector has also been developed. However, this configuration involves two signal conversions, that is, conversion from a digital display signal to an analog RGB signal and conversion from an analog RGB signal to a digital signal for a flat panel display monitor. Cause.

Most digital interfaces for external flat panel display monitors are P
This is realized by a dedicated extended video card such as a CI card. In this method, a PCI expansion video card is mounted on a computer main body, and a digital display signal for an external flat panel display monitor is derived from the expansion video card. Therefore, its use is limited to desktop PCs, and cannot be used for notebook PCs and laptop PCs without expansion slots.

[0005]

As described above, conventional notebook PCs and the like only support an analog RGB interface as an interface for external monitoring, and are expected to rapidly expand into the market in the future. There were problems such as the inability to support a flat panel display monitor with a digital interface.

The present invention has been made in view of the above circumstances, and provides a computer system capable of efficiently using a flat panel display monitor equipped with a digital interface by improving an interface for an external monitor. The purpose is to:

[0007]

In order to solve the above-mentioned problems, a computer system according to the present invention comprises: a computer main body; a built-in flat panel display monitor connected to the computer main body; A digital interface connector to which a flat panel display monitor can be connected, and display control means for controlling both the built-in flat panel display monitor and the external flat panel display monitor using a digital display signal. .

In this computer system, a digital interface connector to which an external flat panel display monitor can be connected is provided on the computer body, and a built-in flat panel display monitor and an external flat panel display connected to the digital interface connector are provided. The monitor and the monitor are both controlled by the same display control means. As a result, both the built-in flat panel display monitor and the external flat panel display monitor can be efficiently controlled by one display control means, and simultaneous display of the built-in flat panel display monitor and the external flat panel display monitor can be performed. It becomes possible.

The display control means converts the multi-bit digital display data into serial data, and converts the serial data into a differential digital display signal for supplying to the external flat panel display monitor. Means for outputting the differential type digital display signal to the digital interface connector.

When a digital display signal is supplied to an external flat panel display monitor, the transmission path of the digital display signal is longer than in the case of the built-in flat panel display monitor. When supplied to a monitor, problems such as radio wave radiation are likely to occur, which may cause deterioration of display quality. In order to solve this problem, the display control means includes means for converting multi-bit digital display data into serial data by parallel-serial conversion and individually converting the serial data into a digital display signal in a differential format. As a result, the number of signal lines can be reduced, the signal voltage level can be reduced, and a failure due to radio wave radiation can be eliminated.

The display control means includes first signal conversion means for converting multi-bit digital display data into a differential first serial digital display signal for supplying the external flat panel display monitor. And a second signal converting means for converting the multi-bit display data into a differential second serial digital display signal for supplying the built-in flat panel display monitor. Thus, electromagnetic interference can be avoided not only for the external flat panel display monitor but also for the built-in flat panel display monitor. Further, by providing separate signal conversion means for the built-in flat panel display monitor and the external flat panel display monitor, signal conversion can be performed according to the characteristics of the built-in flat panel display monitor and the external flat panel display monitor.

Further, the display control means is a one-chip LSI.
Wherein the first and second conversion means are built in a chip of the display control means. Thereby, the mounting area can be reduced.

Further, the computer main body is further provided with an analog RGB interface connector, and the display control means converts the digital display signal into an analog signal and outputs the analog signal to the analog RGB interface connector. The analog RG
The apparatus further comprises means for controlling an external display monitor having an analog interface, which can be connected to the B interface connector. As a result, simultaneous display of three types of display systems can be performed as required, and an external analog monitor such as an analog CRT monitor or an LCD monitor of an analog interface can be used.
An external flat panel display monitor with a digital interface can be selectively used.
The selection between the external analog monitor and the external flat panel display monitor is automatically performed by detecting the presence or absence of the connection.

In order to reduce the mounting area of the connector, a single common connector to which both the external flat panel display monitor and the analog interface external display monitor can be selectively connected may be used. As a result, the user can connect the external display without being conscious of the type of the connector. When such a shared connector is used, the shared connector further includes a monitor determination unit that determines whether an external flat panel display monitor or an external display monitor of an analog interface is connected to the shared connector. The display signal to be output to the common connector may be switched according to the determination result.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a computer system according to an embodiment of the present invention. This computer system is a notebook or sub-notebook type portable personal computer, and comprises a computer main body and a built-in flat panel display 31 such as an LCD panel which is attached to the computer main body so as to be openable and closable.

A PCI bus 1, an ISA bus 2, a CPU module 1
1, a main memory 12, a display controller 13, a PCI interface bridge (PCI I / F) 15, an I / O controller 16, an HDD 17, a BIOS-ROM 18, a keyboard controller (KBC) 19, and the like.

The CPU module 11 controls the operation of the entire system and executes data processing.
Here, a CPU, a cache, and a memory controller for controlling the main memory 12 are mounted.

The main memory 12 is used as a main memory of the system, and includes an operating system,
An application program to be processed, user data created by the application program, and the like are stored. The main memory 12 is a synchronous DR.
This is realized by a semiconductor memory such as an AM.

The display controller 13 controls a built-in flat panel display monitor 31, an external CRT monitor, and an external flat panel display monitor used as a display monitor of the system. External CRT
The monitor is an analog RG provided on the computer body.
The external flat panel display monitor is connected to a digital interface connector 33 provided on the computer main body.

The display controller 13 includes a display controller 131 and a video memory (VRAM) 13 as shown in the figure.
2. D / A converter (DAC) 133 and conversion I
C134. Display controller 131
Controls the display of the data drawn on the VRAM 132 on the display monitor. The display controller 131 outputs a total of 24 bits of digital display data consisting of 6 bits for each of RGB, horizontal / vertical synchronization signals, A clock signal, a display enable signal, and the like are output.

The conversion IC 134 is connected to the display controller 13.
6 is converted to serial data for each of R, G, and B.
Each of the GB serial data is individually converted into a digital display signal of a differential format one bit at a time. The differential digital display signal is supplied to the built-in flat panel display monitor 31 and an external flat panel display monitor connected to the digital interface connector 33.

On the other hand, for an analog external monitor such as an analog CRT monitor connected to the analog RGB interface connector 32, a display controller 131 is provided.
Are output after being converted into analog signals by the DAC 133.

A PCI interface bridge (PCI
The I / F 15 is a gate array realized by a one-chip LSI, which has a built-in bridge function for bidirectionally connecting the PCI bus 1 and the ISA bus 2, a HDD 17, and An IDE controller for controlling various IDE devices (second HDD, CD-ROM drive, DVD drive, etc.) that can be selectively accommodated in the selectable bay 21 provided in the computer main body, and a USB device connected to a USB slot. A USB controller for controlling is also built in.

The I / O controller 16 is a gate array for controlling various I / O devices other than the IDE device and the USB device.
A function to control PC card of CARD BUS specification,
External FD connected via serial port, parallel port, infrared communication port (FIR), dedicated connector
D, and controls the FDD and the like accommodated in the selectable bay 21.

The BIOS-ROM 18 stores a system BIOS.
For storing S (Basic I / O System)
It is composed of a flash memory so that the program can be rewritten. The system BIOS systematizes a function execution routine for accessing various hardware in the system.

Keyboard controller (KBC) 19
Controls a keyboard (KB) and a pointing device such as a pointing stick (PS) or a mouse.

FIG. 2 shows a state in which an external display monitor is connected to the computer system of the present embodiment. From the system board, the built-in flat panel display monitor 31 displays a dedicated harness or LCD
Flexible or flat cables are derived, and the built-in flat panel display monitor 31 has:
The above-described differential serial digital display signal is supplied through such internal wiring.

External flat panel display monitor 4
Reference numeral 1 denotes an LCD or the like equipped with a digital interface, which is used by connecting to a digital interface connector 33 of the computer main body 100 as shown in the figure. The above-described serial digital display signal of the differential format is supplied to the external flat panel display monitor 41 via the digital interface connector 33 and the connection cable.

The external analog CRT monitor 42 is used by being connected to the analog RGB interface connector 32. The aforementioned analog display signal is supplied to the external analog CRT monitor 42 via the analog RGB interface connector 32 and the connection cable.

FIG. 3 shows an external flat panel display monitor 41 and an external analog CRT monitor 42.
FIG. 3 is an external view in the case where is connected. According to the present embodiment,
A digital interface connector 33 to which an external flat panel display monitor 41 can be connected, and an analog RGB connector 32 to which an external analog CRT monitor 42 can be connected are provided on the computer main body 100 of the notebook PC. Display monitor 41 and external analog CRT monitor 4
2 and the built-in flat panel display monitor 31
It is controlled by the same display control device 13. Therefore,
It is possible to efficiently perform display control according to the use environment, such as simultaneous display of the built-in flat panel display monitor 31, the external flat panel display monitor 41, and the external analog CRT monitor 42, and selection display thereof.

Further, instead of directly supplying the digital display data to the external flat panel display monitor 41, the conversion IC 134 converts the multi-bit digital display data into a serial digital display signal of a differential format and then supplies the digital display data. The multi-bit digital display data is directly transmitted to the external flat panel display monitor 4.
Compared with the case of supplying to 1, the number of signal lines can be reduced, and the signal voltage level of the display signal can be reduced, so that an obstacle due to radio wave radiation can be eliminated.

Here, the case where the digital interface connector 33 and the analog RGB connector 32 are provided separately has been described. However, the digital interface connector 33 and the analog RGB connector 32 are combined to realize them as one unified connector. It is also possible. FIG. 4 shows the shape of the unified connector.

This unified connector is used as a common connector to which both the external flat panel display monitor 41 and the external analog CRT monitor 42 can be connected, and the digital interface connector 33
Signal pin and analog RGB connector 3
2 is realized as a D-SUB connector having the same signal pins as those in the second embodiment. Of course, the ground pins and the like can be shared to reduce the number of pins in the unified connector.

The signal pin (33) for the digital interface connector is used for transmitting the serial digital display signal of the above-mentioned differential type, and the signal pin (32) for the analog RGB connector is used for transmitting the analog RGB signal. .

Whether to output a digital display signal or an analog RGB signal to the unified connector is determined by the flat panel monitor detection circuit 135 and the CRT monitor detection circuit 13.
6 is controlled based on the respective detection result signals DET1 and DET2. Flat panel monitor detection circuit 135
Detects whether the external flat panel display monitor 41 is connected to the unified connector by monitoring the voltage of a predetermined signal pin in the signal pin (33) for the digital interface connector. The external flat panel display monitor 41 is basically connected only to the signal pins (33) for the digital interface connector among the signal pins in the unified connector. Therefore, by monitoring the voltage of a specific signal pin (33), the external flat panel display monitor 41 is monitored.
Can be detected.

Similarly, the CRT monitor detection circuit 136
Detects whether the external CRT display 42 is connected to the unified connector by monitoring the voltage of a predetermined signal pin in the signal pin (32) for the analog RGB connector.

The display controller 13 supplies one of a digital display signal and an analog RGB signal to the unified connector based on the detection results of the flat panel monitor detection circuit 135 and the CRT monitor detection circuit 136.

It is to be noted that a USB connector is additionally provided in the unified connector.
Port, P1394, or DDC (Display Data C
For example, a signal pin for a hannel) may be included, thereby realizing a connector having higher versatility.

Even when the digital interface connector 33 and the analog RGB connector 32 are separately provided, the presence or absence of connection of an external monitor to each connector is determined by the flat panel monitor detection circuit 135 and the CRT monitor detection circuit 136. Is detected, and the output and non-output of each of the digital display signal and the analog display signal can be switched according to the detection result.

FIG. 5 shows a second example of the configuration of the display control device 13. In FIG. 5, the aforementioned conversion IC 1
34 and the DAC 133 are integrated on the same chip as the display controller 131. Thus the transformation I
By integrally forming the C134 on the same chip as the display controller 131, it is possible to support the external flat panel display unit 41 without increasing the mounting area on the system board.

FIG. 6 shows a third example of the configuration of the display control device 13. In FIG. 6, a conversion IC 134a for the built-in flat panel display monitor 31 and a conversion IC 134 for the external flat panel display unit 41 are shown.
Two conversion ICs with C134b are provided.

As described above, the built-in flat panel display monitor 31 and the external flat panel display unit 41 have different electrical environments, such as the length of the signal transmission path and whether or not the signal is transmitted via the connector. different. Further, since the type of panel used for the built-in flat panel display monitor 31 is determined by the system maker, a unique signal conversion format or the like suitable for the type can be used. The user can select any of these panels arbitrarily, so it is necessary to adopt a highly versatile signal conversion format. By providing two conversion ICs 134a and 134b as shown in FIG. 6, such a condition can be satisfied.

FIG. 7 shows an example of a specific configuration of each of the conversion ICs 134a and 134b. FIG. 7A shows a conversion IC.
134a, and includes a parallel-serial conversion circuit 201, a PLL 202, and differential signal line drivers 203 to 206 as shown.
The 6-bit R data is supplied to the parallel-serial conversion circuit 20.
1 is converted to serial data. A horizontal synchronization signal HSYNC, a vertical synchronization signal VSYNC, and a data enable signal ENAB indicating a valid display data period are superimposed on the serial data string of the R data and sent to the differential signal line driver 203. In the differential signal line driver 203, "1" / "0" is set for each bit of the serial data.
Is converted to a differential signal and output.

Similarly, the 6-bit G data and the 6-bit B data are also converted into serial data by the parallel-serial conversion circuit 201, respectively.
The corresponding differential signal line drivers 204 and 205 convert the data into a digital display signal of a differential format for each bit.

The clock signal CLK is applied to the PLL 202
After the frequency conversion by the differential signal line driver 20
6 is output in parallel with the data from the differential signal line drivers 203 to 205.

FIG. 7B corresponds to the conversion IC 134b. As shown, the parallel-serial conversion circuit 301, the encoder 302, and the differential signal line driver 30 are provided.
3 to 306.

7A is different from FIG. 7A in that serial data is converted to a differential signal before encoding to improve the noise resistance, and that the horizontal synchronization signal HSYNC,
The point is that the vertical synchronization signal VSYNC and the data enable signal ENAB indicating the valid display data period are superimposed on the clock signal CLK.

As shown in FIG. 8, the conversion ICs 134a and 134b are preferably formed integrally with the DAC 133 on a chip of the display controller 131.
FIG. 9 shows detection signals D from the flat panel monitor detection circuit 135 and the CRT monitor detection circuit 136, respectively.
A configuration example for switching between output / non-output of a digital display signal to the digital interface connector 33 and output / non-output of an analog display signal to the analog RGB interface connector 32 using ET1 and DET2 is shown.

FIG. 9 shows an example in which the present invention is applied to the configuration of the display control device 13 shown in FIG. 6, and a detection signal DET is provided between the conversion IC 134b and the digital interface connector 33.
1 is provided, and a detection signal DET2 is also provided between the DAC 333 and the analog RGB interface connector 32.
There is provided a switch circuit 138 that is turned on / off by the switch. With this configuration, a display signal (digital display signal or analog display signal) corresponding to the connector can be supplied only to the connector to which the external monitor is connected. Of course, simultaneous display is also possible.

The configuration shown in FIG. 9 can be similarly applied to a case where a unified connector is used. Although the above embodiment has been described taking a notebook PC as an example, the present invention can be applied to a desktop PC. In this case, a flat panel display monitor with a digital interface can be used as a display monitor without using a dedicated expansion card or the like. The user can selectively use an analog CRT monitor and a flat panel display monitor with a digital interface.

[0051]

As described above, according to the present invention,
One display control device can support various types of monitors including an external flat panel display monitor equipped with a digital interface. In particular, note P
In C, since a digital display signal equivalent to that of the built-in flat panel display monitor is led out through the connector, an external flat panel display monitor with a digital interface can be used without using a dedicated expansion card or the like. Further, by using a serial digital display signal of a differential type, problems such as radio wave interference can be avoided. Further, by adopting a connector structure in which a digital interface connector for an external flat panel display monitor and an analog RGB connector are unified, it is possible to avoid an increase in a connector mounting area.

[Brief description of the drawings]

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

FIG. 2 is an exemplary view showing a state where an external display monitor is connected to the computer system of the embodiment.

FIG. 3 is an exemplary view showing the appearance when an external display monitor is connected to the computer system of the embodiment.

FIG. 4 is an exemplary view showing an example of a shared connector used in the computer system of the embodiment.

FIG. 5 is an exemplary view showing a second configuration example of the display control device provided in the computer system of the embodiment.

FIG. 6 is an exemplary view showing a third configuration example of the display control device provided in the computer system of the embodiment.

FIG. 7 is an exemplary block diagram showing an example of a specific configuration of a conversion IC provided in the computer system of the embodiment.

FIG. 8 is an exemplary view showing a fourth configuration example of the display control device provided in the computer system of the embodiment.

FIG. 9 is an exemplary view showing an example of a display signal switching circuit provided in the computer system of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... CPU module 12 ... Main memory 13 ... Display control device 31 ... Built-in flat panel display monitor 32 ... Digital interface connector for external flat panel display monitor 33 ... Analog RGB connector 41 ... External flat panel display monitor 42 ... External analog CRT monitor 131 ... Display controller 132 ... VRAM 133 ... DAC 134 ... Conversion IC 134a ... Conversion IC for built-in flat panel display monitor 134b ... Conversion IC for external flat panel display monitor

Claims (11)

[Claims] 1. A computer main body, a built-in flat panel display monitor provided in the computer main body, a digital interface connector provided in the computer main body and connectable to an external flat panel display monitor, and a digital display signal. And a display control means for controlling both the built-in flat panel display monitor and the external flat panel display monitor. 2. The display control means converts a multi-bit digital display data into serial data, and converts the serial data into a differential digital display signal to be supplied to the external flat panel display monitor. 2. The computer system according to claim 1, further comprising a conversion unit for outputting the digital display signal in the differential format to the digital interface connector. 3. The display control means converts multi-bit digital display data into serial data, and converts the serial data into a first digital display signal in a differential format for supplying to the external flat panel display monitor. First signal converting means for converting; converting the multi-bit display data into serial data;
2. The computer system according to claim 1, further comprising second signal conversion means for converting the serial data into a second digital display signal in a differential format for supplying the serial data to the built-in flat panel display monitor. 4. The display control means according to claim 3, wherein said display control means is constituted by a one-chip LSI, and said first and second conversion means are built in a chip of said display control means. Computer system as described. 5. The computer according to claim 1, wherein said computer has an analog R
An analog interface connectable to the analog RGB interface connector by converting the digital display signal into an analog signal and outputting the analog display signal to the analog RGB interface connector; The computer system according to claim 1, wherein the computer system controls an external display monitor having: 6. A means for detecting presence / absence of connection of an external display monitor for each of the digital interface connector and the analog RGB interface connector, based on the detection result, the digital interface connector and the analog RGB interface connector 6. The computer system according to claim 5, further comprising means for controlling supply / interruption of a display signal. 7. The digital interface connector and the analog RGB interface connector include a signal pin in the digital interface connector and a signal pin in the analog RGB interface connector, and the external flat panel display monitor and the external display of the analog interface. 6. The computer system according to claim 5, wherein both monitors are constituted by one common connector that can be selectively connected. 8. A monitor discriminating means for discriminating which of the external flat panel display monitor and the external display monitor of the analog interface is connected to the common connector, and according to a discrimination result of the monitor discriminating means. 6. The computer system according to claim 5, wherein a display signal output to said common connector is switched. And a shared connector provided on the computer body and selectively connectable to both an external flat panel display monitor of a digital interface and an external display monitor of an analog interface. Monitor determining means for determining which of the external flat panel display monitor and the external display monitor of the analog interface is connected; and a digital display signal and an analog display signal transmitted to the shared connector according to the determination result of the monitor determining means. A computer system comprising: display control means for supplying one of them. 10. A computer main body, an analog RGB interface connector provided on the computer main body and connectable to an external display monitor of an analog interface, and a digital interface provided on the computer main body and connectable to an external flat panel display monitor A computer system, comprising: a connector; an external display monitor connected to the analog RGB interface connector; and a display control means for controlling both an external flat panel display monitor connected to the digital interface connector. 11. A means for detecting presence / absence of connection of an external display monitor for each of the digital interface connector and the analog RGB interface connector, based on the result of the detection, for the digital interface connector and the analog RGB interface connector. 11. The computer system according to claim 10, further comprising means for controlling supply / interruption of a display signal.