TWI442654B - Low-voltage differential signaling interface circuit - Google Patents

Description

Low voltage differential signal interface circuit

The present invention relates to a Low-Voltage Differential Signaling (LVDS) interface circuit, and more particularly to an LVDS interface circuit for data transmission between a motherboard and a display panel of a flat panel display.

LVDS interface circuit uses ultra-low voltage swing high-speed differential transmission data, low power consumption, low bit error rate, low crosstalk and low radiation, so it is widely used for signal integrity, low jitter and common mode requirements. In higher systems, such as data transfer between the motherboard and the display panel used in flat panel displays. Please refer to FIG. 1 , which is a circuit diagram of the motherboard 11 and the display panel 12 of the conventional flat panel display 1 using LVDS interface circuit 2 for transmitting data. The LVDS interface circuit 2 includes an output interface circuit 21 disposed on the main board 11, and an input interface circuit 22 disposed on the display panel 12. The output interface circuit 21 includes a first connector 111 and a differential signal transmitter 112, and the input interface The circuit 22 includes a second connector 121 and a differential signal receiver 122.

On the main board 11, the micro controller and the scaler 113 receive the analog or digital video input, and generate RGB image data for output to the differential signal transmitter 112 after processing such as analog to digital conversion, video decoding or image scaling. The differential signal transmitter 112 converts the RGB image data and some control signals into differential signals for output to the first connector 111 such that the main board 11 outputs a differential signal from the first connector 111. On the display panel 12, a differential signal is received from the second connector 121 and output to the differential signal receiver 122. The differential signal receiver 122 inversely converts the differential signals to reproduce the RGB image data and control signals for output to the timing control and row and column driver 123. The timing control and row and column driver 123 drives the pixel array 124 to display an image frame based on the reproduced RGB image data and control signals.

The motherboard 11 of the existing flat panel display 1 and the connector of the LVDS interface circuit 2 used by the display panel 12 (ie, the first connector 111 for outputting differential signals on the main board 11 and the second for receiving differential signals on the display panel 12) There are two types of connectors 121), one is an FFC/FPC connector, and the other is a wafer connector. The FFC is an abbreviation of Flexible Flat Cable, and the FPC is a Flexible Printed Circuit. Abbreviation for printed circuit board).

When the non-display panel production company develops the flat panel display of the first generation or the previous generations, the connectors of the LVDS interface circuit used in the main board and the display panel are usually the same type, so that the data can be directly connected through the existing connection line for data transmission. . For example, referring to FIG. 2, the first connector 111 on the main board 11 and the second connector 121 on the display panel 12 are all FFC connectors, so that the main board 11 and the display panel 12 can directly pass through the existing FFC connecting line 23. connection. The FFC connecting line 23 includes a body 231 and connectors 232 and 233 disposed at two ends of the body 231. The body 231 is an FFC, and the connectors 232 and 233 are both FFC connectors and can be respectively connected to the first connector 111 and the first connector. The two connectors 121 are connected.

However, as the flat panel display has been developed for many generations or the display panel is in short supply, the connectors of the LVDS interface circuit used in the main board and the display panel are often not the same type, so the wiring of the main board needs to be redesigned to use the same type. Connectors, or the development of adapter boards to provide switching between the motherboard and the display panel, thereby increasing design and manufacturing costs and extending the development cycle. For example, referring to FIG. 3, the first connector 111 on the main board 11 and the second connector 121' on the display panel 12 are respectively FFC connectors and strip connectors, so the main board 11 and the display panel 12 need an adapter board. 24 transfer. The adapter plate 24 is provided with connectors 241 and 242 which are electrically connected to each other, and the connectors 241 and 242 are an FFC connector and a bar connector, respectively. The first connector 111 on the main board 11 is connected to the connector 241 on the interposer 24 via the FFC connecting line 23, and the second connector 121' on the display panel 12 passes through the twisted pair cable 25 and the interposer board 24. The connector 242 is connected, so that the main board 11 and the display panel 12 are electrically connected by being transferred through the adapter board 24. The FFC connecting line 23 includes a body 231 and connectors 232 and 233 disposed at two ends of the body 231. The body 231 is an FFC, and the connectors 232 and 233 are both FFC connectors and can be respectively connected to the first connector 111. The device 241 is connected. The twisted pair cable 25 includes a body 251 and connectors 252 and 253 disposed at opposite ends of the body 251. The body 251 is a twisted pair, and the connectors 252 and 253 are strip connectors and can be respectively connected to the connector 242 and the first The two connectors 121' are connected.

The object of the present invention is to provide an LVDS interface circuit, which can directly connect the main board and the display panel directly when the connector of the LVDS interface circuit used in the main board of the flat display and the display panel is different, and the wiring of the main board is not required to be redesigned. Or develop an adapter plate for transfer.

To achieve the above object, the present invention provides an LVDS interface circuit for data transmission between a motherboard and a display panel of a flat panel display. The LVDS interface circuit includes an output interface circuit disposed on the main board, an input interface circuit disposed on the display panel, and a composite connection line for electrically connecting the output interface circuit and the input interface circuit. The output interface circuit includes a first connector and a differential signal transmitter, wherein the differential signal transmitter receives the first signal on the main board and converts the first signal into a differential signal for output to the first connector. The input interface circuit includes a second connector and a differential signal receiver, wherein the differential signal receiver receives the differential signal through the second connector and converts the differential signal into a second signal on the display panel. The composite cable includes a twisted pair and a third connector and a fourth connector disposed at two ends of the twisted pair, wherein the first connector and the third connector are a male and a female first connector, The two connectors and the fourth connector are a male and female second type connectors, and the first type connector and the second type connector are different types of connectors.

In an embodiment of the invention, the first type of connector is an FFC connector or an FPC connector, and the second type of connector is a strip connector.

In one embodiment of the invention, the first type of connector is a strip connector and the second type of connector is an FFC connector or an FPC connector.

In an embodiment of the invention, the first connector is a male first type connector and the third connector is a female first type connector.

In an embodiment of the invention, the first connector is a female first type connector and the third connector is a male first type connector.

In an embodiment of the invention, the second connector is a male second type connector and the fourth connector is a female second type connector.

In an embodiment of the invention, the second connector is a female second type connector and the fourth connector is a male second type connector.

In an embodiment of the invention, the flat panel display is a liquid crystal display, a plasma display or an organic light emitting diode display.

The invention adopts a composite connecting cable, which comprises a twisted pair cable and different types of connectors disposed at two ends of the twisted pair cable, so that the connector of the LVDS interface circuit used on the main board and the display panel can be combined by different types. The cable is directly connected to the main board and the display panel. It is not necessary to redesign the wiring of the main board or develop the adapter board for switching, which solves the limitations of the display panel, thereby reducing the design and manufacturing cost and shortening the development cycle.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Please refer to FIG. 4 , which is a perspective view of an LVDS interface circuit 4 for data transmission between the main board 31 and the display panel 32 of the flat panel display 3 according to an embodiment of the invention. The flat panel display 3 can be a liquid crystal display, a plasma display or an organic light emitting diode display, which includes a main board 31 and a display panel 32. The main board 31 includes a first connector 311, a differential signal transmitter 312, and a micro controller and a scaler 313. The display panel 32 includes a second connector 321, a differential signal receiver 322, a timing control and row and column driver 323, and a pixel. Array 324.

The LVDS interface circuit 4 is used for data transfer between the main board 31 of the flat panel display 3 and the display panel 32. The LVDS interface circuit 4 includes an output interface circuit 41 disposed on the main board 31, an input interface circuit 42 disposed on the display panel 32, and a composite connection line 43 for electrically connecting the output interface circuit 41 and the input interface circuit 42. The output interface circuit 41 is composed of a first connector 311 and a differential signal transmitter 312. The input interface circuit 42 is composed of a second connector 321 and a differential signal receiver 322, and the composite connection line 43 includes a twisted pair. 431 and a third connector 432 and a fourth connector 433 disposed at two ends of the twisted pair 431.

On the main board 31, the micro controller and the scaler 313 receive an analog or digital video input, and generate RGB image data for output to the differential signal transmitter 312 after processing such as analog to digital conversion, video decoding or image scaling. The differential signal transmitter 312 converts the RGB image data and some control signals (collectively referred to as first signals) into differential signals for output to the first connector 311, so that the main board 31 outputs a differential signal from the first connector 311. On the display panel 32, a differential signal is received from the second connector 321 and output to the differential signal receiver 322. The differential signal receiver 322 inversely converts the differential signal to reproduce the RGB image data and the control signal (collectively referred to as the second signal) for output to the timing control and row and column driver 323. The timing control and row and column driver 323 drives the pixel array 324 to display an image frame based on the reproduced RGB image data and control signals.

The first connector 311 on the main board 31 and the third connector 432 of the composite connecting line 43 are a male-type first type connector connectable to each other, and the second connector 321 and the composite on the display panel 32. The fourth connector 433 of the type connection cable 43 is a male and female second type connector connectable to each other, and the first type connector and the second type connector are different types of connectors. Therefore, by connecting the third connector 432 of the composite connection line 43 with the first connector 311 on the main board 31, and the fourth connector 433 of the composite connection line 43 and the second connector on the display panel 32 The 321 connection can electrically connect the output interface circuit 41 on the main board 31 and the input interface circuit 42 on the display panel 32, thereby providing data transmission between the main board 31 and the display panel 32, so that the main board 31 and the display panel 32 can pass directly. The composite connecting wires 43 are electrically connected.

In this embodiment, the first connector 311 and the third connector 432 are first type connectors, that is, FFC connectors or FPC connectors, wherein the first connector 311 is a socket fixed on the main board 31. A jack connector is a female connector using socket contacts, and a third connector 432 is a plug connector provided at one end of the twisted pair 431 of the composite connecting line 43. (plug connector) and is a male connector using pin contacts. The second connector 321 and the fourth connector 433 are both a second type connector, that is, a strip connector, wherein the second connector 321 is a socket connector fixed on the display panel 32 and is in contact with the pin. The male connector of the piece, and the fourth connector 433 is a plug connector provided at the other end of the twisted pair 431 of the composite connecting wire 43 and is a female connector using the jack contact. However, this embodiment does not limit the present invention. For example, the first connector may be replaced with a male connector and the third connector may be replaced with a female connector, or the second connector may be replaced with a female connector and the fourth connector may be used instead. Male connector.

In another embodiment, referring to FIG. 5, the first connector 311' and the third connector 432' are both first type connectors, that is, strip connectors, wherein the first connector 311' is fixed. The socket connector on the main board 31 is a male connector using a pin contact member, and the third connector 432' is a plug connector provided at one end of the twisted pair 431 of the composite connecting line 43 and is a jack Female connector for the contact. The second connector 321 ′ and the fourth connector 433 ′ are both a second type connector, that is, an FFC connector or an FPC connector, wherein the second connector 321 ′ is a socket connector fixed on the display panel 32 . And it is a female connector using a jack contact, and the fourth connector 433' is a plug connector provided at the other end of the twisted pair 431 of the composite connecting line 43 and is a male connector using a pin contact. However, this embodiment does not limit the present invention. For example, the first connector may be replaced with a female connector and the third connector may be replaced with a male connector, or the second connector may be replaced with a male connector and the fourth connector may be used instead. Female connector.

In summary, the present invention adopts a composite connecting cable, which comprises a twisted pair cable and different types of connectors disposed at two ends of the twisted pair cable, so that the connectors of the LVDS interface circuit used on the main board and the display panel are different types. The motherboard and the display panel can be directly connected through the composite cable, and the layout of the display panel can be reduced without redesigning the wiring of the motherboard or developing the adapter board to reduce the design and manufacturing cost and shorten the development cycle.

While the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

1, 3. . . Flat panel display

11, 31. . . Motherboard

111, 311, 311'. . . First connector

112, 312. . . Differential signal transmitter

113, 313. . . Micro controller and scaler

12, 32. . . Display panel

121, 121', 321, 321'. . . Second connector

122, 322. . . Differential signal receiver

123, 323. . . Timing control and row and column drivers

124, 324. . . Pixel array

2, 4. . . LVDS interface circuit

21, 41. . . Output interface circuit

22, 42. . . Input interface circuit

23, 25. . . Cable

231, 251. . . Ontology

232, 233, 252, 253. . . Connector

twenty four. . . Adapter plate

241, 242. . . Connector

43. . . Composite cable

431. . . Twisted pair

432, 432’. . . Third connector

433, 433’. . . Fourth connector

FIG. 1 is a circuit diagram of a motherboard and a display panel of a conventional flat panel display using LVDS interface circuits for transmitting data.

2 is a perspective view showing the connector of the LVDS interface circuit used in the main board and the display panel of FIG. 1 in the same type.

FIG. 3 is a perspective view showing the connector of the LVDS interface circuit used in the main board and the display panel of FIG. 1 in different types.

4 is a perspective view of an LVDS interface circuit for data transmission between a motherboard and a display panel of a flat panel display according to an embodiment of the invention.

FIG. 5 is a perspective view of an LVDS interface circuit for data transmission between a main board and a display panel of a flat display according to another embodiment of the present invention.

3. . . Flat panel display

31. . . Motherboard

311. . . First connector

312. . . Differential signal transmitter

313. . . Micro controller and scaler

32. . . Display panel

321. . . Second connector

322. . . Differential signal receiver

323. . . Timing control and row and column drivers

324. . . Pixel array

4. . . LVDS interface circuit

41. . . Output interface circuit

42. . . Input interface circuit

43. . . Composite cable

431. . . Twisted pair

432. . . Third connector

433. . . Fourth connector

Claims (8)

A low voltage differential signal interface circuit for data transmission between a main board and a display panel of a flat display, the low voltage differential signal interface circuit comprising:
An output interface circuit is disposed on the motherboard, including a first connector and a differential signal transmitter, wherein the differential signal transmitter receives a first signal on the motherboard and converts the first signal into a differential signal Output to the first connector;
An input interface circuit is disposed on the display panel, and includes a second connector and a differential signal receiver, wherein the differential signal receiver receives the differential signal through the second connector and converts the differential signal into the a second signal on the display panel; and a composite cable including a twisted pair and a third connector and a fourth connector disposed at two ends of the twisted pair, wherein the first connector and the first connector The third connector is a male and female first type connector, the second connector and the fourth connector are a male and a female second type connector, and the first type connector and the second type Connectors are different types of connectors. The low voltage differential signal interface circuit according to claim 1, wherein the first type connector is a flexible cable connector or a flexible printed circuit board connector, and the second type connector is a strip connector. The low voltage differential signal interface circuit according to claim 1, wherein the first type connector is a strip connector, and the second type connector is a flexible cable connector or a flexible printed circuit board connector. The low voltage differential signal interface circuit of claim 1, wherein the first connector is a male first type connector, and the third connector is a female first type connector. The low voltage differential signal interface circuit of claim 1, wherein the first connector is a female first type connector, and the third connector is a male first type connector. The low voltage differential signal interface circuit of claim 1, wherein the second connector is a male second type connector, and the fourth connector is a female second type connector. The low voltage differential signal interface circuit of claim 1, wherein the second connector is a female second type connector, and the fourth connector is a male second type connector. The low voltage differential signal interface circuit according to claim 1, wherein the flat display is a liquid crystal display, a plasma display or an organic light emitting diode display.