Display device and source driver

Abstract

To provide a display device which reduces the number of signal lines connected to a source driver and the source driver, source drivers being cascaded by serial communication regarding the display device and the source driver.SOLUTION: A plurality of source drivers is connected to the same display panel and drives pixels of the display panel. The source driver comprises: a cascade connection section which cascades the source driver with the other source driver via a serial communication line; and a communication control section which uses a horizontal synchronizing signal acquired from the outside as a synchronizing signal of a serial communication to perform the serial communication with the other source driver via the cascade connection section.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a display device and a source driver. [Background technology]

[0002] Patent Document 1 describes a display device including a display panel having a plurality of data lines and a plurality of gate lines, and a plurality of pixel switches and a plurality of pixel units arranged in a matrix at each of the intersections of the plurality of data lines and the plurality of gate lines, a display controller that outputs a video data signal, a gate driver that supplies gate signals to the plurality of gate lines that control the pixel switches to be on, and a plurality of source drivers that are arranged along the extension direction of the gate lines, each of which receives a video data signal from the display controller and generates a grayscale voltage signal to be supplied to each of the plurality of pixel units based on the video data signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-135394 A Summary of the Invention [Problem to be solved by the invention]

[0004] A plurality of source drivers for driving a display panel of a display device are connected to each other in a cascade configuration.

[0005] This makes it possible, for example, when an abnormality occurs in one of the source drivers, to notify the other source drivers of the abnormality, and to simultaneously control all source drivers connected to the display panel in the event of an abnormality.

[0006] If communication between source drivers via cascade connection is performed using parallel communication, the number of signal lines between the source drivers will be large. Therefore, in order to reduce the number of signal lines connected to the source drivers, it is possible to perform communication between source drivers via cascade connection using serial communication.

[0007] However, in order to perform serial communication between multiple source drivers, it is necessary to connect a signal line to each source driver to supply a synchronizing signal for serial communication, which creates a problem in that the number of signal lines connected to the source drivers increases by the number of signal lines for supplying the synchronizing signals for serial communication.

[0008] In consideration of the above circumstances, the present invention aims to provide a display device and a source driver in which source drivers are cascade-connected via serial communication, and in which the number of signal lines connected to the source drivers is reduced. [Means for solving the problem]

[0009] The display device of the present disclosure comprises a display panel having pixels arranged in a matrix, a plurality of gate lines extending in the row direction of the matrix, and a plurality of source lines extending in the column direction of the matrix, a gate driver that applies a scanning signal to the gate lines based on a horizontal synchronization signal to select pixels, and a plurality of source drivers that drive pixels of the display panel via the source lines based on the horizontal synchronization signal, each of the plurality of source drivers comprising a cascade connection unit that cascade connects with other source drivers via serial communication lines, and a communication control unit that performs serial communication with the other source drivers via the cascade connection unit using a horizontal synchronization signal obtained from outside as a synchronization signal for serial communication.

[0010] The source driver of the present disclosure is a source driver that is connected in multiple instances to the same display panel and drives pixels of the display panel, and includes a cascade connection unit that cascade connects to other source drivers via a serial communication line, and a communication control unit that performs serial communication with the other source drivers via the cascade connection unit using a horizontal synchronization signal obtained from outside as a synchronization signal for serial communication. Effect of the Invention

[0011] According to the display device and source driver of the present disclosure, it is possible to provide a display device and source driver in which the source drivers are cascade-connected via serial communication, and in which the number of signal lines connected to the source drivers is reduced. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating a configuration of a liquid crystal display device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a schematic configuration of a source driver. [Diagram 3] 2 is a block diagram showing a schematic configuration of a cascade signal control circuit; [Figure 4] FIG. 4 is a diagram for explaining signals during serial communication. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the overall configuration of a liquid crystal display device 1 according to one embodiment of the present invention.

[0014] 1, a liquid crystal display device 1 according to this embodiment includes a liquid crystal display panel 100, a gate driver 10, a plurality of source drivers 20, and a system controller 30. The liquid crystal display device 1 is an example of a display device in the technology of the present disclosure.

[0015] The liquid crystal display panel 100 includes liquid crystal pixels 110 arranged in a matrix, a plurality of gate lines 111 extending in the row direction of the matrix, and a plurality of source lines 112 extending in the column direction of the matrix. The liquid crystal display panel 100 is an example of a display panel in the technology of the present disclosure.

[0016] The gate driver 10 sequentially applies scanning signals to the gate lines 111 based on gate control signals supplied from a source driver 20 (described later) to set the liquid crystal pixels 110 in a selected state.

[0017] Based on a horizontal synchronization signal supplied from a system controller 30 described below, the source driver 20 supplies a display signal voltage corresponding to a video data signal provided from the system controller 30 to each liquid crystal pixel 110 selected by the gate driver 10 via a source line.

[0018] A plurality of source drivers 20 are connected to the liquid crystal display panel 100. The plurality of source drivers 20 are arranged along the extension direction of the gate lines 111. The source drivers 20 are connected to each other by two serial communication lines 40. In this embodiment, an example in which two source drivers 20 are connected to the liquid crystal display panel 100 will be described.

[0019] The system controller 30 generates a vertical synchronizing signal and a horizontal synchronizing signal based on a synchronizing signal input from the outside, and supplies them to the source driver 20. The system controller 30 also generates a video data signal for displaying desired image information on the liquid crystal display panel 100 based on a video data signal supplied from the outside, and outputs the video data signal to the source driver 20. The system controller 30 also supplies each source driver 20 with a position information signal indicating the arrangement order of the source drivers 20 relative to the liquid crystal display panel 100.

[0020] The source driver 20 generates a gate control signal for controlling the gate driver 10 based on the vertical synchronization signal and horizontal synchronization signal received from the system controller 30, and operates in conjunction with the gate driver 10 based on this gate control signal to apply a display signal voltage to each liquid crystal pixel 110 at a predetermined timing, thereby controlling the liquid crystal display panel 100 to display the desired image information.

[0021] Next, the configuration of the source driver 20 will be described in detail. FIG. 2 is a block diagram showing a schematic configuration of the source driver 20. FIG. 3 is a block diagram showing a schematic configuration of a cascade signal control circuit. FIG. 4 is a diagram for explaining signals during serial communication. Note that in FIGS. 2 to 4, "cascade" is written as "CA." Also, in FIG. 3, "enable" is written as "EN."

[0022] As shown in FIG. 2, the source driver 20 includes a cascade signal control circuit 21, an IO (Input / Output) circuit 22, an output pad 23, an input pad 24, an abnormality detection circuit 25, a control signal generation circuit 26, and a processing circuit 27.

[0023] The cascade signal control circuit 21 is a control circuit for performing serial communication with other source drivers 20 via an output pad 23 and an input pad 24, using the horizontal synchronizing signal supplied from the system controller 30 as a synchronizing signal for serial communication. The cascade signal control circuit 21 is an example of a communication control unit in the technology of the present disclosure.

[0024] The IO circuit 22 is a circuit that inputs and outputs data between the cascade signal control circuit 21 and the output pad 23 and input pad 24. The output pad 23 and input pad 24 are an example of a cascade connection unit that cascade connects to another source driver 20 via a serial communication line 40. The output pad 23 of one source driver 20 and the input pad 24 of the other source driver 20 are mutually connected by the serial communication line 40. In addition, the input pad 24 of one source driver 20 and the output pad 23 of the other source driver 20 are mutually connected by the serial communication line 40.

[0025] The abnormality detection circuit 25 is a circuit for detecting an abnormality, such as a temperature abnormality, within the source driver 20. A plurality of abnormality detection circuits 25 may be provided according to the type of abnormality to be detected.

[0026] The control signal generating circuit 26 is a circuit that generates control signals for the source driver 20 itself or other source drivers 20, such as for synchronizing the lighting state of the liquid crystal display panel 100. A plurality of control signal generating circuits 26 may be provided depending on the types of control signals to be generated.

[0027] The processing circuit 27 is a circuit for carrying out processing within its own source driver 20 on the basis of a signal acquired from another source driver 20.

[0028] As shown in FIG. 3, the cascade signal control circuit 21 specifically includes a cascade output signal generating section 51, a cascade output enable signal generating section 52, a parallel-serial conversion section 53, and a serial-parallel conversion section .

[0029] The cascade output signal generation unit 51 generates parallel signals to be transmitted to other source drivers 20 based on input signals input, for example, from the abnormality detection circuit 25 and the control signal generation circuit 26, and a cascade output enable signal input from the cascade output enable signal generation unit 52.

[0030] In order to perform serial communication with other source drivers 20, the parallel-serial conversion unit 53 converts the parallel signal output from the cascade output signal generation unit 51 into a serial signal using the horizontal synchronizing signal supplied from the system controller 30 as a synchronizing signal for serial communication.

[0031] In order to perform serial communication with other source drivers 20, the serial-parallel conversion unit 54 converts the serial signal obtained from the other source driver 20 into a parallel signal, using the horizontal synchronizing signal supplied from the system controller 30 as a synchronizing signal for serial communication.

[0032] 4, the cascade output signal includes a plurality of signals [1] to [N]. Similarly, the cascade input signal includes a plurality of signals [1] to [N].

[0033] In the source driver 20 of this embodiment, the parallel-serial conversion unit 53 converts a parallel signal made up of a plurality of cascade output signals [1] to [N] into a serial signal based on the horizontal synchronization signal supplied from the system controller 30.

[0034] Specifically, the parallel-serial conversion unit 53 inserts a start pulse indicating that this is the first data in the serial signal at the timing of the rising edge of the horizontal synchronizing signal, and subsequently obtains and arranges the parallel signal data of the cascade output signals [1] to [N] in order at each rising edge of the horizontal synchronizing signal, thereby converting the parallel signal into a serial signal. After that, the parallel-serial conversion unit 53 repeatedly executes the above process.

[0035] Furthermore, in the source driver 20 of this embodiment, the serial-parallel conversion unit 54 converts a serial signal acquired from another source driver 20 into a parallel signal composed of multiple cascade input signals [1] to [N] based on the horizontal synchronization signal supplied from the system controller 30.

[0036] Specifically, the serial-parallel conversion unit 54 detects a start pulse at the timing of the rising edge of the horizontal synchronization signal, and separates the data following the start pulse into the data of the cascade input signals [1] to [N] at each timing of the rising edge of the horizontal synchronization signal, thereby converting the serial signal into a parallel signal. After that, the serial-parallel conversion unit 54 repeatedly executes the above process.

[0037] That is, serial communication between the source drivers 20 in cascade connection is performed by a full-duplex communication method in which transmission and reception are performed by different serial communication lines 40 .

[0038] This makes it possible to reduce the number of signal lines for cascade connection between the source drivers 20, as compared to the case where parallel signals are transmitted directly through parallel signal lines.

[0039] For example, if the cascade output signal is composed of four signals [1] to [4] and the cascade input signal is composed of four signals [1] to [4], when transmitting via parallel communication, eight signal lines are required for cascade connection between the source drivers 20. However, as described above, when transmitting via serial communication using the full-duplex communication method, only two signal lines are required.

[0040] In addition, a horizontal synchronization signal is commonly supplied to each of the multiple source drivers 20 from the system controller 30, and the cascade signal control circuit 21 of each source driver 20 performs serial communication using the horizontal synchronization signal supplied from the system controller 30 as a synchronization signal for serial communication.

[0041] Therefore, it is not necessary to connect a separate signal line to the source driver 20 for supplying a synchronous signal for serial communication.

[0042] As a result, in the source driver 20 of this embodiment, the number of signal lines required for cascade connection, which are connected to the source driver 20, can be reduced.

[0043] [Variations] Although the liquid crystal display device 1 according to one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment and can be modified as appropriate.

[0044] For example, the display panel is not limited to the liquid crystal display panel 100 described above, but may be any type of display panel that is driven using a plurality of source drivers 20, such as an OLED (Organic Light Emitting Diode) display panel.

[0045] In addition, in the above embodiment, the serial communication through cascade connection between the source drivers 20 was a full-duplex communication method in which transmission and reception were performed using different serial communication lines 40, but it may also be a half-duplex communication method in which transmission and reception are performed using the same serial communication line.

[0046] In addition to the above, appropriate modifications may be made to the description and illustrations shown above, such as deleting unnecessary parts, adding new elements, or making substitutions, within the scope of the gist of the technology disclosed herein. [Explanation of symbols]

[0047] 1 LCD display device 10 Gate Driver 20 Source Driver 21 Cascade signal control circuit 22 IO circuit 23 Output Pad 24 Input Pad 25 Abnormality detection circuit 26 Control signal generation circuit 27 Processing Circuit 30 System Controller 40 Serial communication line 51 Cascade output signal generator 52 Cascade output enable signal generator 53 Parallel serial conversion section 54 Serial-to-parallel conversion section 100 Liquid crystal display panel 110 LCD pixels 111 Gate Line 112 Source Line

Claims

1. a display panel having pixels arranged in a matrix, a plurality of gate lines extending in a row direction of the matrix, and a plurality of source lines extending in a column direction of the matrix; a gate driver that applies a scanning signal to a gate line based on a horizontal synchronization signal to select a pixel; a plurality of source drivers for driving pixels of the display panel through source lines based on a horizontal synchronization signal; Each of the plurality of source drivers a cascade connection unit that cascade-connects to other source drivers via a serial communication line; a communication control unit that performs serial communication with another source driver via the cascade connection unit by using a horizontal synchronizing signal obtained from an external source as a synchronizing signal for serial communication. Display device.

2. The communication control unit a parallel-serial conversion unit that converts a parallel signal into a serial signal for serial communication with another source driver; a serial-to-parallel conversion unit that converts a serial signal acquired from another source driver into a parallel signal in order to perform serial communication with the other source driver; The display device according to claim 1 .

3. A source driver connected to a single display panel for driving pixels of the display panel, a cascade connection unit that cascade-connects to other source drivers via a serial communication line; a communication control unit that performs serial communication with another source driver via the cascade connection unit by using a horizontal synchronizing signal obtained from an external source as a synchronizing signal for serial communication. Source driver.

4. The communication control unit a parallel-serial conversion unit that converts a parallel signal into a serial signal for serial communication with another source driver; a serial-to-parallel conversion unit that converts a serial signal acquired from another source driver into a parallel signal in order to perform serial communication with the other source driver; The source driver according to claim 3 .

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