Display module and display device

Patent metadata

Field	Value
Publication number	US-12288516-B2
Application number	US-202218257385-A
Country	US
Kind code	B2
Filing date	Jun 24, 2022
Priority date	Jun 24, 2022
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

A display module includes a display panel, at least one bonding circuit board, a plurality of chip-on-films, and a plurality of buffer devices. The at least one bonding circuit board each include first differential lines, and a first differential line includes a P-polarity differential sub-line and an N-polarity differential sub-line. An end of a chip-on-film is connected to the first differential line, and the other end of the chip-on-film is connected to the display panel. The buffer devices are arranged on the bonding circuit board, a buffer device is connected to ends, proximate to the chip-on-film, of the P-polarity differential sub-line and the N-polarity differential sub-line, and the buffer device is configured to reduce signal reflection between the first differential line and the chip-on-film.

First claim

What is claimed is:

1. A display module, comprising:
a display panel;
at least one bonding circuit board, each including first differential lines, wherein a first differential line includes a P-polarity differential sub-line and an N-polarity differential sub-line;
a plurality of chip-on-films, wherein an end of a chip-on-film is connected to the first differential line, and an other end of the chip-on-film is connected to the display panel; and
a plurality of buffer devices, arranged on the bonding circuit board, wherein a buffer device is connected to ends, proximate to the chip-on-film, of the P-polarity differential sub-line and the N-polarity differential sub-line, and the buffer device is configured to reduce signal reflection between the first differential line and the chip-on-film; wherein
the chip-on-film includes a low-voltage differential signaling (LVDS) interface circuit, the LVDS interface circuit includes a first signal receiving terminal, a second signal receiving terminal, a signal output terminal and a second resistor, wherein
the first signal receiving terminal is connected to the P-polarity differential sub-line, the second signal receiving terminal is connected to the N-polarity differential sub-line, and the signal output terminal is connected to the display panel; an end of the second resistor is connected to the first signal receiving terminal, and an other end of the second resistor is connected to the second signal receiving terminal.

2. The display module according to claim 1 , wherein the buffer device includes a first resistor, an end of the first resistor is connected to the P-polarity differential sub-line, and an other end of the first resistor is connected to the N-polarity differential sub-line.

3. The display module according to claim 2 , wherein the first resistor satisfies one or more of:
that a resistance of the first resistor is substantially equal to an impedance of the first differential line;
that a value of the resistance of the first resistor is 100 ohms (Ω); and
that the first resistor includes a chip resistor, and a package size of the chip resistor is less than or equal to a 0402 package size.

4. The display module according to claim 1 , wherein the buffer device includes a low-voltage differential signaling (LVDS) buffer, and the LVDS buffer includes a first input terminal, a second input terminal, a first output terminal and a second output terminal; the chip-on-film is connected to the first differential line through the LVDS buffer, wherein
the first input terminal is connected to the P-polarity differential sub-line, the second input terminal is connected to the N-polarity differential sub-line, and the first output terminal and the second output terminal are connected to the chip-on-film.

5. The display module according to claim 1 , wherein a distance between the P-polarity differential sub-line and the N-polarity differential sub-line is less than or equal to a line width of each of the P-polarity differential sub-line and the N-polarity differential sub-line.

6. The display module according to claim 1 , wherein a resistance of the second resistor is substantially equal to an impedance of the first differential line; and the second resistor includes two sub-resistors connected in series, and resistances of the two sub-resistors are equal.

7. The display module according to claim 1 , wherein the display module comprises a plurality of bonding circuit boards, the plurality of bonding circuit boards are arranged at intervals along a first direction, and the first direction is parallel to a side edge of the display panel where the plurality of bonding circuit boards are located;
the display module further comprises:
a driving circuit board, configured to output differential signals; and
a plurality of flexible connectors, each bonding circuit board being connected to the driving circuit board through one or more flexible connectors, wherein
the plurality of flexible connectors each include a wiring layer, the wiring layer includes second differential lines, an end of a second differential line is connected to the driving circuit board, and an other end of the second differential line is connected to the first differential line.

8. The display module according to claim 7 , wherein in at least one flexible connector, each flexible connector further includes: at least one shielding layer, arranged on at least one side of a wiring layer included in the flexible connector along a thickness direction of the wiring layer, wherein the shielding layer covers second differential lines included in the wiring layer.

9. The display module according to claim 8 , wherein another at least one flexible connector each are not provided with a shielding layer therein, and a length of a flexible connector provided with a shielding layer is greater than a length of a flexible connector not provided with a shielding layer.

10. The display module according to claim 7 , wherein a dimension, along the first direction, of the driving circuit board is greater than a distance, along the first direction, between two bonding circuit boards of the plurality of bonding circuit boards at both ends; along a second direction, at least a portion of each bonding circuit board is opposite to the driving circuit board, and the first direction is perpendicular to the second direction; and
the portion of each bonding circuit board opposite to the driving circuit board is connected to the driving circuit board through the one or more flexible connectors.

11. The display module according to claim 10 , wherein lengths of the plurality of flexible connectors are substantially equal; and/or
an extension direction of a length of the flexible connector is substantially parallel to the second direction.

12. The display module according to claim 10 , wherein the driving circuit board includes a main body portion and extension portions located at two opposite sides of the main body portion along the first direction, and dimensions of the extension portions along the second direction each are less than a dimension of the main body portion along the second direction; and
the driving circuit board further includes a timing controller, arranged on the main body portion and configured to output the differential signals.

13. The display module according to claim 7 , wherein the plurality of bonding circuit boards include a first bonding circuit board and a second bonding circuit board arranged adjacent to each other; along a second direction, at least a portion of the first bonding circuit board is opposite to the driving circuit board, and the second bonding circuit board is staggered from the driving circuit board; the first direction is perpendicular to the second direction; and
the plurality of flexible connectors include a first flexible connector, a second flexible connector, and a third first flexible connector, wherein
the first bonding circuit board is connected to the driving circuit board through the first flexible connector and the second flexible connector; the first flexible connector is configured to transmit a differential signal required by a chip-on-film connected to the first bonding circuit board, and the second flexible connector is configured to transmit a differential signal required by a chip-on-film connected to the second bonding circuit board; and
an end of a third flexible connector is connected to the first bonding circuit board, and an other end of the third flexible connector is connected to the second bonding circuit board; and the differential signal transmitted by the second flexible connector is transmitted to the

Assignees

• Hefei Boe Joint Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Bao Wenchao
• Wu Yue
• Li Huihui
• Liu Miao
• Xu Cheng
• Xu Jingbo

Classifications

• G09G2370/14

  Use of low voltage differential signaling [LVDS] for display data communication · CPC title

• G09G2320/0219

  Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling · CPC title

• G09G2310/0291

  Details of output amplifiers or buffers arranged for use in a driving circuit · CPC title

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G3/3648 Primary

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title