KR102316559B1 - Display Module and Display Device - Google Patents

Abstract

The present invention relates to a display module and a display device that can easily release a write protection function after assembling the device or after mass production, and the display module includes a display panel including a plurality of gate lines and data lines; , a memory mounted on a printed circuit board and having a write protection terminal, a timing controller mounted on the printed circuit board, a negative logic circuit mounted on the printed circuit board and connected to the write protection terminal, and and a connector connected to the input terminal of the negative logic circuit to receive a voltage signal from the outside.

Description

Display Module and Display Device

The present invention relates to a display device, and more particularly, to a display module and a display device capable of easily releasing a write protection function after assembling the device or after mass production.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms, and in recent years, a liquid crystal display (LCD), a plasma display panel (PDP), an organic electric field Various flat display devices such as an organic electroluminescent display device (OELD) are being used.

Among these flat panel display devices, the liquid crystal display device has the advantages of miniaturization, light weight, thinness, and low power driving, and has been widely used in recent years.

As a liquid crystal display device, an active matrix type liquid crystal display device in which a switching transistor is formed in each pixel arranged in a matrix form is commonly used.

In such an active matrix type liquid crystal display device, when the gate wiring is scanned, a scan pulse having a gate high voltage is applied to turn on the switching transistor. In synchronization with this, the data voltage is transmitted through the data line and applied to the corresponding pixel. Accordingly, the data voltage is applied to the pixel electrode of the corresponding pixel, and the corresponding light is emitted.

Such a liquid crystal display device includes a control circuit such as a timing controller, and a driving circuit provided in the liquid crystal display device is controlled through a control signal generated from the timing controller. In generating such a control signal, the timing controller reads timing data stored in an external memory (EEPROM: Electrically Erasable Programmable Read Only Memory), and a control signal is generated according to the timing data.

Meanwhile, the liquid crystal display may be driven by various driving methods. For example, a driving method called over driving may be used to improve a slow response speed of liquid crystal. Here, the overdriving method corresponds to a driving method of comparing image data of a previous frame input to one pixel with image data of a current frame, and modulating the image data of the current frame when a difference occurs. For example, when the image data value of the current frame is higher than the image data value of the previous frame, the image data value of the current frame is further increased, and when the image data value of the current frame is lower than the image data value of the previous frame In this case, the image data value of the current frame is further lowered.

In order to perform such overdrive, an overdrive circuit is provided in the liquid crystal display, and the overdrive circuit reads overdrive data stored in an external memory (EEPROM), and according to such overdrive data, image data of the current frame Overdrive processing is performed for .

As described above, driving data, such as timing data and overdrive data, used for driving the liquid crystal display device is stored in the external memory (EEPROM).

Meanwhile, after data is written in the external memory formed on the PCB, the external memory maintains a write protection state for stabilization of the supplied data or the generated timing signal. However, there are cases in which data change is required in an external memory to be used after assembling the device or after mass production. In a conventional liquid crystal display device, an external memory (EEPROM) is connected to a write protection terminal, so it is difficult to change the data. For example, the write-protection function is performed by physically shorting the write-protection terminal portion to release the write-protection function in the external memory, and connecting the physically short-circuited terminal portion again to perform the write-protection function. There is a problem in that it is difficult to change the data of

The present invention has been devised to solve the above problems, and relates to a display module and a display device capable of easily releasing a write protection function after assembling the device or after mass production.

A display device of the present invention for achieving the above object includes a display panel including a plurality of gate lines and data lines, a memory mounted on a printed circuit board and having a write protection terminal, and a memory mounted on the printed circuit board, a timing controller, a negative logic circuit mounted on the printed circuit board and connected to the write protection terminal, an interface for transmitting image data and a power voltage signal from the system, and a voltage signal output terminal of the interface and the negative logic circuit It is characterized in that it includes a connector for connecting a logic circuit.

The voltage signal output terminal of the interface selects and transmits a power supply voltage signal and a ground signal to the negative logic circuit, and transmits a power voltage signal only in a write state, and the voltage signal output terminal of the interface selects a power supply voltage signal and a ground signal in a write state. transmit a signal

The display module and display device of the present invention have the following effects.

By providing a negative logic circuit connected to the write protection terminal of the memory (EEPROM) on the printed circuit board, the write protection can be easily released by changing the voltage level at the interface side. That is, even when the printed circuit board is assembled and maintained as a write protection function by being covered by a cover shield, etc., it is possible to rewrite the memory only by changing the voltage state in the interface side on the outside of the display panel or display module. Even after mass production, data correction is possible if necessary. It is possible to significantly reduce the cost and time required for rework compared to the method of dismantling the conventional cover shield, shorting the resistance terminal of the write protection terminal, and repairing it.

1 is a diagram schematically showing a display device according to the present invention;
FIG. 2 is a circuit diagram illustrating a sub-pixel of FIG. 1 ;
3 is a diagram illustrating an example of writing data in a memory;
4 is a view showing a connection in a test state after writing data in the display module of the present invention;
5 is a diagram illustrating a connection when data is changed in the display module of the present invention;
6 is a view illustrating a connection state between an interface and a display module after final data change in the display device of the present invention;

Hereinafter, a display module and a display device of the present invention will be described in detail with reference to the drawings.

Although a liquid crystal display device is mentioned as an example of the display device described below, the present invention is not limited thereto, and all flat panel display devices in which data is written through a memory may be applied.

Also, as described below, a 'display module' includes a display panel and a driver for lines formed thereon, and a 'display device' is a SET such as a system and an interface in addition to the display module.

In addition, when a separate light source is required, like a liquid crystal display device, the liquid crystal display module may further include a backlight unit.

FIG. 1 is a diagram schematically illustrating a display device according to the present invention, and FIG. 2 is a circuit diagram illustrating a sub-pixel of FIG. 1 .

1 and 2, the display device of the present invention includes first and second substrates 100 and 200 bonded to each other, a liquid crystal layer (not shown) filled therebetween, and the first substrate ( A thin film transistor (TFT) for driving the gate lines GL1 to GLn and the data lines DL1 to DLm crossing each other and the liquid crystal cell Clc formed at the intersection is formed on the 100 ). The display panel 1000 including the display panel 1000 , the data driver 120 for supplying data signals to the data lines DL1 to DLm of the display panel 1000 , and the gate lines GL1 to GL1 to DLm of the display panel 100 . GLn) includes a gate driver 110 for supplying a scan signal, and a timing controller 130 for controlling the gate driver 110 and the data driver 120 .

In addition, the timing controller 130 is mounted on the printed circuit board 160 , the memory 140 having a write protection terminal WP on the printed circuit board 160 , and the write protection terminal WP on the write protection terminal WP. It includes a connected negative logic circuit (not gate) 155 .

In addition, an interface 250 for transmitting image data and a power voltage signal from the external system 300 and a connector 180 connecting the voltage signal output terminal of the interface 250 and the negative logic circuit 155 are It is located outside the printed circuit board 160 .

In the illustrated display device, writing to the memory 140 has been completed and included in the set. In this case, the interface 250 includes a voltage supply source therein, and the ground terminal of them is connected to the connector 180 and the connector 180 . connected, and a ground signal is applied to the input terminal of the negative logic circuit. That is, in the display device, the input of the negative logic circuit 155 goes to a low level, the output thereof goes to a high level, and a high level signal is actually applied to the write protection terminal WP, so that the final write protection mode is executed. it has been

Meanwhile, the memory 140 is written in the state of the display module during the manufacturing process of the display device. A specific example will be described below with reference to FIG. 4 .

Although not shown in the drawings, the display device includes a DC-DC converter (not shown) that generates various power voltages for driving the display panel 1000 using power supplied from the outside, and a data driver by generating a gamma reference voltage. It further includes a gamma voltage generator (not shown) for supplying the 120 .

In the display panel 1000 , a thin film transistor (TFT) is formed as a switching element for each liquid crystal cell. A gate electrode of the thin film transistor TFT is connected to the gate lines GL1 to GLn, a source electrode is connected to the data lines DL1 to DLm, and a drain electrode is a pixel electrode and a storage capacitor of the liquid crystal cell Clc. (Cst) is connected to one electrode. A common voltage Vcom is supplied to the common electrode of the liquid crystal cell Clc, and the storage capacitor Cst charges the data voltage supplied from the data lines DL1 to DLm when the thin film transistor TFT is turned on. It serves to keep the voltage of the liquid crystal cell Clc constant.

When the scan pulse is sequentially supplied to the gate lines GL1 to GLn, the thin film transistor TFT is turned on to form a channel between the source electrode and the drain electrode to transmit the voltage on the data lines DL1 to DLm to the liquid crystal cell. (Clc) is supplied to the pixel electrode. At this time, the liquid crystal molecules of the liquid crystal cell Clc change the arrangement by the electric field between the pixel electrode and the common electrode to modulate the incident light.

The data driver 120 supplies the data signal to the data lines DL1 to DLm in response to the data driving control signal DCS supplied from the timing controller 130 . In addition, the data driver 120 samples and latches the image data (R, G, B Data) inputted from the timing controller 130 , and then the display panel 1000 based on the gamma reference voltage supplied from the gamma voltage generator. It is converted into an analog data voltage capable of expressing grayscale in the liquid crystal cell Clc of , and supplied to the data lines DL1 to DLm.

Here, the data driving control signal DCS supplied from the timing controller 130 includes SSP, SSC, SOE, POL, and the like.

The gate driver 110 sequentially generates a scan pulse according to the gate driving control signal GCS supplied from the timing controller 130 , that is, the gate driver 110 sequentially generates a scan pulse to the gate lines GL1 to GLn. supplied with

Here, the gate driving control signal GCS supplied from the timing controller 130 includes GSP, GSC, GOE, and the like.

The timing controller 130 provides a vertical/horizontal synchronization signal (Vsync/Hsync), a data enable signal (DE), a clock signal (Clk), and data signals (R, G) supplied from the system 300 through the interface 250 . , B Data) to control the data driver 120 and the gate driver 110 .

In addition, the interface 250 converts data and timing signals from the system 300 to the timing controller 130 to a level suitable for a corresponding display panel, and the interface 250 is printed through the connector 180 . It is connected to the circuit board 160 . In addition, in the input/output terminal for transmitting the voltage of the connector 180 , the voltage signal output terminal of the interface 250 is connected to the input terminal of the connector 180 , and the output terminal of the connector 180 is connected to the negative logic circuit ( 155) is connected to the input terminal.

3 is a diagram illustrating an example of writing data in a memory.

The example of FIG. 3 is a comparative example, and shows a state in which data is changed after writing to the memory.

In this case, the memory has a write-protect terminal 7, a serial clock signal terminal 6, a serial data terminal 5, and a power supply voltage/ground voltage terminal 1, 2, 3, 4, 8. In a state in which writing is executed to the memory, a high-level signal is applied to the write protection terminal 7 to execute write protection, and data is held.

At this time, in the comparative example, in order to change data, the resistor connected to the write protection terminal 7 of the memory is short-circuited to put the terminal in a floating state, the write protection is released, and the serial clock signal terminal 6 The serial clock signal and serial data signal are transmitted to the and serial data terminal 5, respectively.

However, after the data writing protection state is already set, it is often the case that the printed circuit board is adhered to the back side of the display panel and the cover shield is covered. By shorting the device and executing the data change, a physical operation was necessary to change the data.

Unlike this comparative example, in the display module and display device of the present invention, the change after data writing is performed by changing the voltage level applied by the display module driving board without physical change on the printed circuit board, and the time required for data change rework can reduce

Hereinafter, a normal state and a data change state of the display device of the present invention will be described with reference to the drawings.

In the vicinity of the memory represented in the drawings below, the memory on the printed circuit board 160 and the negation logic circuit 155 connected thereto are shown, and one side of the connector is connected to apply a voltage signal to the negation logic circuit 155 . 180 and the interface 250 or the display module driving board 350 connected to the other side of the connector 180, and the remaining parts are omitted.

4 is a diagram illustrating a connection in a test state after writing data in the display module of the present invention, and FIG. 5 is a diagram illustrating a connection when data is changed in the display module of the present invention.

4 and 5 , in the display module of the present invention, a memory 140 is provided on a printed circuit board 160 , and the memory 140 has a total of eight terminals. The number of the terminals may be increased or decreased.

The 1st, 2nd, and 8th terminals of the memory receive the power voltage signal Vcc, and the 3rd and 4th terminals of the memory are grounded (the ground signal GND is applied).

In addition, the 5th to 7th terminals of the memory can change the state of the applied signal. The 5th and 6th terminals are a serial data terminal and a serial clock terminal, respectively, and the 6th terminal is a write protection terminal (WP). In a normal state, the write protection terminal is maintained at a high level, so that signals from the serial data terminal and the serial clock terminal cannot be written into the memory 140 .

In addition, for stabilization of each terminal, a first resistor R11 is provided between the write protection terminal WP, which is the seventh terminal of the memory, and the ground terminal, and a second resistor R11 is provided between the sixth terminal, the serial clock terminal, and the power supply voltage terminal. A second resistor R12 is provided, and a third resistor R13 is provided between the fifth terminal, the serial data terminal, and the power voltage terminal. In addition, the write protection terminal WP of the memory may be connected to the write protection terminal provided on the printed circuit board 160 through the fourth resistor R14. In addition, a capacitor C11 may be provided between the power supply voltage terminal and the ground terminal. The first to fourth resistors R1 to R4 and the capacitor C11 may be omitted in some cases.

In addition, the negative logic circuit 155 connected to the write protection terminal WP may be provided on the printed circuit board 160 in the form of an IC, or may be circuitly formed on the printed circuit board 160 using transistors and resistors. By design, it can be done.

Meanwhile, in the display module, even when data writing is completed in the memory 140 , the connector 180 is connected to the display module driving board 350 to test the display state of the display module, and the test is performed.

In addition, once data writing is completed, a ground signal GND is output from the voltage supply source 355 provided in the display module driving board 350 to execute the write protection mode through the connector 180 . applied to the negative logic circuit 155 .

The write protection terminal WP is connected to a negation logic circuit 155 , and the negation logic circuit receives a ground signal ( GND) is approved. Accordingly, the output of the negative logic circuit 155 receiving the ground signal from the input terminal becomes a high level, and transmits it to the write protection terminal WP to set a writing protection mode of the memory 140 . will become

In this case, even if the write state in the memory 140 is completed and the assembly is completed after the write protection is set, and a cover shield (not shown) covers the printed circuit board 160 , the voltage of the negative logic circuit 155 is The signal application is performed on the interface 250 side, so that the write protection setting is possible even when the cover shield (not shown) is covered.

Meanwhile, although not shown, the memory 140 is connected to an I2C (Inter-IC), the write protection terminal WP provided on the printed circuit board 160 , a serial clock terminal, and a serial data terminal. Communication through a protocol may also be performed.

When data change is required during testing using the display module driving board, data write or data change is performed as shown in FIG. 5 . In some cases, data change may be required even after the write-protect mode has been set.

In this case, as shown in FIG. 5 , the external ROM writing device 400 and the display module driving board 350 are connected, and the display module driving board 350 is connected by the writing operation of the external ROM writing device 400 . ), a serial data signal and a serial clock signal are transmitted to the memory 140 through the connector 180 .

Before the write operation, it is necessary to release the write protect mode by applying a low level signal to the write protect terminal WP of the memory.

At this time, since the write protection terminal WP is connected to the negative logic circuit 155 , the voltage signal output from the voltage supply source 355 in the display module driving board 350 is converted to a high level (3.3V). Thus, it is applied to the input terminal of the negative logic circuit through the connector 180 . The output of the negative logic circuit 155 receiving the high level signal from the input terminal becomes a low level, and transmits it to the write protection terminal WP to release the writing protection mode of the memory 140, Accordingly, the serial clock signal and serial data signal are transmitted from the ROM writing device 400 to the serial clock terminal and serial data terminal of the memory 140 via the display module driving board 350 and the connector 180 . It is possible to change data stored in the memory 140 after being authorized.

Meanwhile, although not shown, the memory 140 may be connected to an I2C (Inter-IC) provided on the printed circuit board 160 , a serial clock terminal, and a serial data terminal to perform communication through an I2C protocol. .

6 is a diagram illustrating a connection state between an interface and a display module after final data change in the display device of the present invention.

Finally, after data writing into the memory is completed, the display panel is assembled into a set. In this case, the above-described display module driving board is separated from the display module, and the connector is connected to the interface 250 connected to the system.

At this time, the connector 180 receives a signal from the system (see 300 in FIG. 1 ) and is connected to the system 300 to convert a signal generated in the system 300 into a driving signal suitable for the display panel. The interface 250 is used, and one terminal of the terminals supplying the voltage of the interface 250 is connected to the connector, and a voltage signal applied to the input terminal of the negative logic circuit 155 is constantly converted to the ground signal (GND). Thus, it is possible to finally maintain the write-protected state.

6 shows a state in which the memory 140 and the timing controller 130 share a serial data signal terminal and a serial clock signal terminal. Data and clocks written in the memory 140 from the actual printed circuit board 160 Indicated to cause information to be supplied to the timing controller 130 .

Accordingly, the display device according to the present invention includes a negative logic circuit connected to the write protection terminal of the memory (EEPROM) on the printed circuit board, so that the write protection can be easily released by changing the voltage level at the interface side. That is, even when the printed circuit board is assembled and maintained as a write protection function by being covered by a cover shield, etc., it is possible to rewrite the memory only by changing the voltage state in the interface side on the outside of the display panel or display module. Even after mass production, data correction is possible if necessary. It is possible to significantly reduce the cost and time required for rework compared to the method of dismantling the conventional cover shield, shorting the resistance terminal of the write protection terminal, and repairing it.

On the other hand, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those of ordinary skill in the art.

100: first substrate 110: gate driver
120: data driver 130: timing controller
140: memory 155: negative logic circuit
160: printed circuit board 180: connector
200: second substrate 250: interface
300: system 350: display module driving board
355: voltage source
400: ROM writing device

Claims (8)

a display panel including a plurality of gate lines and data lines;
a memory mounted on a printed circuit board and having a write protection terminal, a power supply voltage terminal, and a ground terminal;
a timing controller mounted on the printed circuit board;
a negative logic circuit mounted on the printed circuit board and connected to the write protection terminal;
a power supply voltage signal supply source and a ground signal supply source respectively connected to the power supply voltage terminal and the ground terminal of the memory on the printed circuit board;
a connector connected to the input terminal of the negative logic circuit through a wiring on the printed circuit board to receive a voltage signal from the outside; and
a cover shield covering the memory, the timing controller, the negative logic circuit, the power supply voltage signal supply source and the ground signal supply source on the printed circuit board;
The connector is selectively connected to any one of an external display module driving board and an interface,
The display module driving board and the interface each have a voltage supply source connected to the connector. The method of claim 1,
The connector is connected to a voltage signal output terminal of the display module driving board through an internal wiring, and applies the voltage signal through the internal wiring through the voltage source and the voltage signal output terminal of the display module driving board under,
The connector selectively transmits a power voltage signal and a ground signal to an input terminal of the negative logic circuit through the wiring on the printed circuit board and transmits the voltage signal as the voltage signal. 3. The method of claim 2,
The voltage signal output terminal of the display module driving board is
When data is written and changed in the memory, the power supply voltage signal is output as the voltage signal,
a display module configured to output the ground signal as the voltage signal when the display module is tested. 3. The method of claim 2,
The display module driving board transmits the power voltage signal to the connector only in the write state of the memory. 3. The method of claim 2,
The display module driving board transmits the ground signal to the connector other than the write state of the memory. 5. The method of claim 4,
In the write state of the memory, the display module driving board has one side temporarily connected to the connector and the other side connected to a ROM writing device. a display panel including a plurality of gate lines and data lines;
a memory mounted on a printed circuit board and having a write protection terminal, a power supply voltage terminal, and a ground terminal;
a timing controller mounted on the printed circuit board;
a negative logic circuit mounted on the printed circuit board and connected to the write protection terminal;
a power supply voltage signal supply source and a ground signal supply source respectively connected to the power supply voltage terminal and the ground terminal of the memory on the printed circuit board;
a connector connected to an input terminal of the negative logic circuit through a wiring on the printed circuit board;
a cover shield covering the memory, the timing controller, the negative logic circuit, the power supply voltage signal source, and the ground signal source on the printed circuit board; and
Transmitting image data and voltage signals from the system, comprising an interface connected to the connector,
The interface is outside the cover shield and includes a voltage supply source to apply a selected signal from among a ground signal and a power voltage signal to an input terminal of the negative logic circuit through the connector. 8. The method of claim 7,
The connector is connected to the interface through an internal wiring, and receives the ground signal and the power supply voltage signal from the voltage source of the interface through the internal wiring,
The connector selectively transmits the power supply voltage signal and the ground signal to an input terminal of the negative logic circuit through the wiring on the printed circuit board.

Images