Display apparatus to detect a connecting state of a cable

This application claims the benefit of Korean Patent Application No. 2005-0057151, filed on Jun. 29, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

1. Field of the Invention

The present general inventive concept relates to a display apparatus, and more particularly, to a display apparatus connected to an external video source, such as a computer, through a video cable and to supply information about a connecting state of the video cable.

2. Description of the Related Art

Generally, a display apparatus displays an image on a screen based on a video signal supplied from an external video source as being connected with the external video source such as a computer. Here, the display apparatus and the computer are connected through a video cable.

In the display apparatus, a connector of the video cable connecting between the display apparatus and the computer may be not properly connected or may be disconnected from the computer or the display apparatus. In this case, the image is not displayed on the screen of the display apparatus.

However, a user of the display apparatus may misconceive that the display apparatus has a problem when the image is not displayed by a disconnection of the video cable as described above.

U.S. Pat. No. RE 38,537 discloses a controller sensing whether a display apparatus and a computer are normally connected. That is, in a state that the display apparatus and the computer are normally connected, a pin(P 1 ) which is connected to a SYNC GND terminal of a connector and allocated in a microprocessor of the display apparatus, is grounded at a ground of the computer, thereby becoming a ‘low’ state, and in a case that the connector is released or disconnected, power connected through a pull up resistance (R 1 ) is applied to the pin (P 1 ), thereby becoming a ‘high’ state. Accordingly, the controller senses that the display apparatus and the computer are normally connected, according to the ‘high’ state.

Recently, a two-way video connector which comprises a first cable connector for connecting the video cable connecting between the computer and the display apparatus to the computer, and a second cable connector for connecting the video cable to the display apparatus, has been used. However, a connection state of the first cable connector and the second cable connector cannot be detected.

The present general inventive concept provides a display apparatus capable of supplying information about a connecting state of a first cable connector and a second cable connector of a video cable connecting the display apparatus and an external video source

Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

The foregoing and other aspects of the present general inventive concept may be achieved by providing a display apparatus connected with an external video source through a video cable having a first cable connector and a second connector connected to the external video source, the display apparatus comprising a display connector having a plurality of signal pins to which the first cable connector is connected, a connecting sensor connected at least two or more the plurality of signal pins to output a first connecting sense signal to inform a first connecting state between the first cable connector and the display connector, and a second connecting sense signal to inform a second connecting state between the second cable connector and the external video source, and a controller to output information about a third connecting state between the first cable connector and the second cable connector based on the first and the second connecting sense signals from the connecting sensor.

The signal pins of the display connector may comprise a first signal pin released from a first ground when the first cable connector and the display connector is disconnected, and a second signal pin released from a second ground when the second cable connector and the external video source is disconnected.

The connecting sensor may comprise a first ground detector connected with the first signal pin to output the first connecting sense signal as a first logic value corresponding to whether the first signal pin is grounded, and a second ground detector connected with the second signal pin to output the second connecting sense signal as a second logic value corresponding to whether the second signal pin is grounded.

The signal pins of the display connector may further comprise a third signal pin grounded at a third ground provided in the display apparatus, and the first signal pin is grounded and connected to the third signal pin through the video cable in a state that the first cable connector is connected to the display connector.

The second signal pin may be grounded at the second ground provided in the external video source in a state that the first cable connector and the second cable connector are respectively connected to the display connector and the external video source.

The display apparatus may further comprise signal lines of the video cable which are respectively connected to the first signal pin and the second signal pin and independently grounded each other.

The display apparatus may further comprise a connecting state display part on which information about the connecting state of the first cable connector and the second cable connector is displayed by the controller.

The connecting state display part may comprise a display part on which the information about the connecting state of the first cable connecter and the second cable connecter is displayed as an image.

The first cable connector, the second cable connector, and the display connector have a D-sub connector connecting structure; and the second signal pin of the display connector may be a SYNC ground pin.

The foregoing and other aspects of the present general inventive concept may also be achieved by providing a display apparatus comprising a display connector having a first signal pin to be connected to a first signal line of an external cable to receive a first ground signal, a second signal pin to be connected to a second signal line of the external cable to receive a second ground signal, a third signal pin to be connected to a third signal line of the external cable, and a fourth signal pin to be connected to a fourth signal line of the external cable to receive one of data and a video signal, a first ground connected to the third signal pin so that the first signal pin receives the first ground signal through the first and third signal pins, and a controller having a first terminal connected to the first signal pin to receive the first ground signal and a second terminal connected to the second signal pin to receive the second ground signal to generate a connection state signal according to the first and second ground signal.

The foregoing and other aspects of the present general inventive concept may also be achieved by providing display apparatus comprising a display connector having first, second, third, and fourth signal pins, a first ground connected to the third signal pin, a cable having first and second cable connectors connected through first, second, third, and fourth signal lines, which are respectively connected to the first, second, third, and fourth signal pins of the display connector, the second cable connectors connected to an external apparatus, and a controller having a first terminal connected to the first signal pin and a second terminal connected to the second signal line to generate a connecting state according to signals from the first and second signal pins.

The above and other features and advantages of the present general inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 illustrates connecting relations between a display apparatus and a computer according to an embodiment of the present general inventive concept;

FIG. 2 illustrates a connecting structure of a connector of the display apparatus of FIG. 1 ;

FIG. 3 illustrates a connecting state of the connector according to a pin state of a controller of the display apparatus of FIG. 2 ; and

FIGS. 4A and 4B illustrate an error message to be displayed on the display apparatus of FIGS. 1 and 2 .

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present invention by referring to the figures.

Referring to FIG. 1 , a display apparatus 20 according to an embodiment of the present general inventive concept is connected with an external video source (i.e., a computer 10 ) through a video cable 30 .

The video cable 30 includes a first cable connector 31 connecting to a display connector 21 provided in the display apparatus 20 , a second cable connector 32 connected to a main body connector 11 provided in the computer 10 , and a signal line part 33 connecting the first cable connector 31 and the second cable connector 32 .

Referring to FIG. 2 , the display apparatus 20 according to the present embodiment includes a display part 24 on which an image is displayed, the display connector 21 to which the first cable connector 31 of the video cable 30 is connected so as to receive the video signal, a video processor 23 to convert the video signal received through the video cable 30 and the display connector 21 into a signal which is formatted so as to allow the display part 24 to display and applying the signal to the display part 24 , and a controller 25 to control the display part 24 , the display connector 21 , and the video processor 23 .

A D-Sub connector connecting structure may be used as the main body connector 11 , the first cable connector 31 , the second cable connector 32 and the display connector 21 according to the present embodiment.

The display connector 21 includes a plurality of signal pins connected with the first cable connector 31 . For example, with the connecting structure of the D-Sub connector, the signal pins of the first cable connector 31 may include a signal pin for an R, G, and B video signal, a signal pin for a horizontal and vertical synchronous signal, a ground pin, and extra pins.

The display apparatus 20 according to the present embodiment includes a connecting sensor 22 connected to two or more of the plurality of signal pins of the first cable connector 31 to output a first connecting sense signal to inform a user of a first connecting state between the first cable connector 31 and the display connector 21 , and a second connecting sense signal to inform the user of a second connecting state between the second cable connector 32 and the main body connector 11 of the computer 10 .

The controller 25 senses a third connecting state of the first cable connector 31 and the second cable connector 32 based on the first and the second connecting sense signals from the connecting sensor 22 . The third connection state may include at least one of the first and second connecting states.

Referring to FIG. 2 , the signal pins of the display connector 21 include a first signal pin 21 a released (or disconnected) from a first ground when the first cable connector 31 and the display connector 21 are released (or disconnected), and a second signal pin 21 b released (or disconnected) from a second ground when the second cable connector 32 and the main body connector 11 of the computer 10 are released (or disconnected).

The second signal pin 21 b is grounded at the second ground provided in the computer 10 in a state that the first cable connector 31 and the second cable connector 32 are respectively connected to the display connector 21 and the main body connector 11 of the computer 10 .

The first signal pin 21 a is grounded at the first ground provided in the display apparatus 20 though a third signal pin 21 c of the display connector 21 in a state that the first cable connector 31 and the display connector 21 are connected. The second signal pin 21 b is grounded at the second ground provided in the computer 10 . Signal lines of the video cable 30 respectively connected to the first signal pin 21 a and the third signal pin 21 c may be connected with each other by being grounded at the signal line part 33 of the video cable 30 in common (refer to a portion ‘A’ of FIG. 2 ). Although the first signal pin 21 a and the third signal pin 21 c are electrically connected through the portion A of the signal lines of the video cable 30 , the signal line having the portion A may not be connected to the second ground disposed in the computer 10 . According to an embodiment of the present general inventive concept, the signal line having the portion A is connected to the second ground disposed in the computer 10 . Accordingly, the first signal pin 21 a may be grounded and connected with the third signal pin 21 c through the video cable 30 in the state that the first cable connector 31 and the display connector 21 are connected. The first signal pin 21 a is released (or disconnected) from the first ground when the first cable connector 31 and the display connector 21 are disconnected.

The signal lines of the video cable 30 respectively connected to the first signal pin 21 a and the second signal pin 21 b ay be independently grounded, thereby preventing the first signal pin 21 a and the second signal pin 21 b from being grounded at the same ground in the video cable 30 . The video cable 30 further includes other signal lines to transfer data and/or the video signal from the computer 10 to the display apparatus 20 .

Meanwhile, the connecting sensor 22 includes a first ground detecting part connected with the first signal pin 21 a of the display connector 21 to output the first connecting sense signal of the logic value corresponding to the ground of the first signal pin 21 a, and a second ground detecting part connected with the second signal pin 21 b to output the second connecting sense signal of the logic value corresponding to the ground of the second signal pin 21 b.

The first ground detecting part according to the present embodiment may include a first full up resistance R 1 branched (connected) from a line which connects between the first signal pin 21 a and a first terminal P 1 of the controller 25 , and a first power supplying terminal V 1 to supply power through the first full up resistance R 1 . Therefore, in a state that the first signal pin 21 a is grounded, the first terminal P 1 of the controller 25 becomes a ‘low’ state (L), and in a state that the first signal pin 21 a is released (or is not grounded), the first terminal P 1 is a ‘high’ state (H) since the power from the first power supplying terminal V 1 is applied to the first pin P 1 of the controller 25 through the first full up resistance R 1 .

And also, the second ground detecting part according to the present embodiment may include a second full up resistance R 2 branched (connected) from a line which connects between the second signal pin 21 b and a second terminal P 2 of the controller 25 , and a second power supplying terminal V 2 applying power through the second full up resistance R 2 . Therefore, in a state that the second signal pin 21 b is grounded, the second terminal P 2 of the controller 25 becomes a low state, and in a state that the ground of the second signal pin 21 b is released (or the second signal pin 21 b is not grounded), the second terminal P 2 is a high state since the power from the second power supplying terminal V 2 is applied to the second terminal P 2 of the controller 25 through the second full up resistance R 2 .

Hereinafter, a method that the controller 25 recognizes a ground state (or a connection state) of the first cable connector 31 and the second cable connector 32 according to the first terminal P 1 and the second terminal P 2 will be described with reference to FIGS. 3 and 4 .

The controller 25 recognizes that the first cable connector 31 and the second cable connector 32 are normally connected to the display connector 21 and the main body connector 11 of the computer 10 , respectively, when the controller 25 recognizes that both the first terminal P 1 and the second terminal P 2 are the ‘low’ state.

When the first cable connector 31 and the display connector 21 are normally connected, and the second cable connector 32 and the main body connector 11 of the computer 10 is not connected, the controller 25 recognizes that the first terminal P 1 is the ‘low’ state and the second terminal P 2 is the ‘high’ state. At this time, referring to FIG. 4A , the controller 25 controls the video processor 23 to inform a user of a first error message representing that the connection of the second cable connector 32 is released or display the image corresponding to the first error message at the display part 24 . The error message displayed at the display part 24 corresponds to an On Screen Display (OSD) image based on video data included in the video processor 23 . Although the present embodiment describes that the controller 25 recognizes that the first terminal P 1 is the ‘low’ state and the second terminal P 2 is the ‘high’ state when the second cable connector 32 and the main body connector 11 of the computer 10 is not connected, the present general inventive concept is not limited thereto. That is, it is possible that the controller 25 recognizes that the first terminal P 1 is the ‘high’ state and the second terminal P 2 is the ‘low’ state according to an arrangement of circuit components of the display connector 21 , the connecting sensor 22 , and the signal part 33 .

Further, when the connection of the first cable connector 31 and the display connector 21 is released, the controller 25 recognizes that both the first terminal P 1 and the second terminal P 2 are the ‘high’ state. At this time, referring to FIG. 4B , the controller 25 controls the video processor 23 to inform the user of a second error message representing that the connection of the first cable connector 31 is released or display the image corresponding to the second error message at the display part 24 . The first or second error message displayed at the display part 24 corresponds to an On Screen Display (OSD) based on the video data comprised in the video processor 23 .

The foregoing embodiment illustrates that the controller 25 displays the image corresponding to the received video signal and/or representing the information about the connection state of the first cable connector 31 and the second cable connector 32 through the display part 24 . Alternatively, the display apparatus 20 according to the present embodiment may comprise a respective connecting state display part on which the information about the connection state of the first cable connector 31 and/or the second cable connector 32 is displayed by controlling of the controller 25 . For example, the connecting state display part may be an LED which is on and off according to the connection state of the first cable connector 31 and/or the second cable connector 32 .

It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.