Adapter

A display adapter includes first and second conversion circuits, a switch unit, and a video graphics array (VGA) interface. The first conversion circuit includes a digital to analog (D/A) converter and a coupler. The second conversion circuit includes an analog to digital (A/D) converter and a decoupler. When the switch unit connects the first conversion circuit to the VGA interface, the D/A converter converts a digital signals representing VGA data into a first analog form data for coupling with a first alternating current (AC) voltage. When the switch unit connects the second conversion circuit to the VGA interface, the decoupler decouples and separates a second analog form data into the second analog form data. The A/D converter converts the second analog form data into digital signals representing VGA data, and outputs the digital signals representing VGA data to the VGA interface for use by another VGA display device.

CROSS-REFERENCE TO RELATED APPLICATIONS

Relevant subject matter is disclosed in the co-pending U.S. patent application Ser. Nos. 13/442,937, 13/442,953, 13/442,956, 13/442,959, 13/442,965, 13/442,970, 13/442,977, 13/442,981, 13/442,988, and 13/442,994 having the same title and assigned to the same assignee as named herein.

TECHNICAL FIELD

The present disclosure relates to adapters, and particularly, to a display adapter.

DESCRIPTION OF RELATED ART

If media such as videos in a first room are shared to other displays in a second room, a conversion device needs to be connected between the displays in the first and second rooms through cables. This is troublesome, untidy, and inconvenient.

DETAILED DESCRIPTION

Referring toFIGS. 1 to 3, an embodiment of a display adapter100includes an enclosure10, an alternating current (AC) power plug20, a video graphics array (VGA) interface30, a first conversion circuit40, a second conversion circuit50, a switch unit60, and a voltage conversion circuit200. The AC power plug20is mounted on the enclosure10to be connected to an AC power socket70. The VGA interface30is mounted on the enclosure10to be connected to a display80. The switch unit60is connected between the VGA interface30and each of the first and second conversion circuits40and50, to connect either the first conversion circuit40or the second conversion circuit50to the VGA interface30. When the display80which is connected to the display adapter100functions as a signal transmission terminal, the switch unit60connects the first conversion circuit40to the VGA interface30. When the display80which is connected to the display adapter100functions as a signal receiving terminal, the switch unit60connects the second conversion circuit50to the VGA interface30. In the embodiment, the switch unit60is a manual switch.

The first conversion circuit40includes a compression control chip41, a digital to analog (D/A) converter42, a coupler43, and a first AC filter44. The second conversion circuit50includes a decompression control chip51, an analog to digital (A/D) converter52, a decoupler53, and a second AC filter54.

The compression control chip41is connected to the switch unit60. The D/A converter42is connected between the compression control chip41and the coupler43. The coupler43is connected to the AC power plug20through the first AC filter44. The AC power plug20is also connected to the decoupler53through the second AC filter54. The A/D converter52is connected between the decoupler53and the decompression control chip51. The decompression control chip51is connected to the switch unit60.

The voltage conversion circuit200includes a third AC filter210, an alternating current to direct current (AC/DC) converter220, a voltage adjustor230, and a DC filter240. In view of the likelihood of random noise in the AC voltage, the third AC filter210is connected to the AC power plug20to receive the AC voltage, and filters the noise from the AC voltage. The AC/DC converter220is connected between the third AC power filter210and the voltage adjustor230, to convert the AC voltage into a DC voltage, and outputs the DC voltage to the voltage adjustor230. The voltage adjustor230adjusts the received DC voltage. In view of the possibility of random noise in the adjusted DC voltage, the DC filter240is connected between the voltage adjustor230and the VGA interface30to filter the noise from the adjusted DC voltage and output the filtered DC voltage to the VGA interface30, to power the display80connected to the VGA interface30.

Referring toFIGS. 4 and 5, an example describes a working principle of the display adapter100. A first display adapter101is inserted into a first AC power socket71in a first room300. A second display adapter102is inserted into a second AC power socket72in a second room400. The first AC power socket71is connected to the second AC power socket72through a commercial AC power line90. The first and second display adapters101and102have the same function and structure as the above-mentioned display adapter100. A first display81is connected to the VGA interface30of the first display adapter101in the first room300. A second display82is connected to the VGA interface30of the second display adapter102in the second room400.

When the first display81in the first room300functioning as a signal transmission terminal communicates with the second display82in the second room400functioning as a signal receiving terminal, the switch unit60of the first display adapter101is switched to connect the first conversion circuit40to the VGA interface30of the first display adapter101, and the switch unit60of the second display adapter102is switched to connect the second conversion circuit50to the VGA interface30of the second display adapter102.

The first display81outputs a digital signal representing VGA data to the VGA interface30of the first display adapter101. The compression control chip41receives the digital signal representing VGA data through the switch unit60, compresses the digital signal representing VGA data into one or more data packets, and outputs the one or more data packets to the D/A converter42. The D/A converter42converts the one or more data packets into an analog form (analog form data) suitable for transmission over an AC voltage which functions as a carrier wave, and outputs the analog form data to the coupler43. The coupler43couples the analog form data to an AC voltage and outputs the AC voltage coupled with the analog form data to the first AC power socket71. The first AC filter44filters the noise from the AC voltage coupled with the analog form data, and outputs the AC voltage coupled with the analog form data to the AC power line90through the AC power plug20and the AC power socket71.

The AC power line90transmits the AC voltage coupled with the analog form data to the second AC filter54through the AC power socket72and the second power plug20in the second room400. The second filter54filters any noise from the AC voltage coupled with the analog form data, and outputs the filtered AC voltage coupled with the analog form data to the decoupler53. The decoupler53decouples and separates the AC voltage coupled with the analog form data e into the AC voltage and the analog form data, and outputs the analog form data to the A/D converter52. The A/D converter52converts the analog form data into the one or more data packets, and outputs the one or more data packets to the decompression control chip51of the second display adapter102. The decompression control chip51decompresses the data packet into the digital signals representing VGA data, and outputs the digital signals representing VGA data to the second display82through the switch unit60and the VGA interface30in the second room400. Therefore, the first display101in the first room300and the second display102in the second room400can freely share VGA data through any commercial AC power line90.