KR20220077059A - Backlight apparatus for display - Google Patents

Abstract

The present invention discloses a backlight device for a display providing a backlight, the backlight device comprising: a backlight driving board for providing column data for the backlight of the display; and a storage unit configured to store current deviation compensation data, a backlight board that provides the backlight and includes a plurality of light emitting blocks divided into a plurality of control units and current control circuits corresponding to the plurality of control units; The backlight driving board receives the current deviation compensation data of the storage unit and outputs the column data compensated by the current deviation compensation data.

Description

BACKLIGHT APPARATUS FOR DISPLAY

The present invention relates to a backlight device, and more particularly, to a backlight device for a display that provides a backlight for displaying an image on a display panel.

Among display panels, for example, an LCD panel requires a backlight device to display an image.

The backlight device provides a backlight for displaying an image on the LCD panel, and the LCD panel may display an image using the backlight by performing an optical shutter operation for each pixel.

The backlight device may include a backlight board, wherein the backlight board includes light emitting diode channels using an LED as a light source, and the light emitting diode channels may emit light to provide a backlight.

The backlight board includes light emitting diode channels to implement a backlight having a resolution different from that of the LCD panel image, and emission of the light emitting diode channels may be controlled by column signals and row signals.

In a conventional backlight device performing dimming control, it is difficult to maintain light emission of light emitting diode channels during one frame. If the light emitting diode channel does not sufficiently maintain light emission, flicker may occur. Therefore, the backlight device needs to adopt a design for reducing or eliminating flicker.

In addition, the backlight device needs to be designed to have an efficient control structure for realizing the backlight.

In addition, the backlight device is configured to use a large number of light emitting diode channels. The light emitting diode channels have a current deviation with respect to the light emitting input voltage. The current deviation may be understood to be caused by an input offset voltage acting on the light emitting input voltage, and the LED channels may emit light with different brightness even in the same column signal due to the current deviation.

The above-described current deviation may be large at a low current of 20 uA to 200 uA, which is controlled with respect to an input value of a low voltage of 1 mV to 100 mV.

Because the effect of the deviation of the input offset voltage on the light emission input voltage for dimming control is greater as the light emission driving voltage is lower, the current deviation due to the input offset voltage is higher than the light emission driving voltage in the high current band where the light emission driving voltage is high. It may appear relatively large in the low current band where the voltage is low.

The uniformity of the image quality of the backlight device may be evaluated as gray uniformity and dark uniformity which is darker than that.

Gray uniformity and dark uniformity are evaluated in the low current band. Therefore, the current deviation due to the input offset voltage may act as a cause of deterioration of gray uniformity and dark uniformity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight device for a display that reduces or eliminates flicker.

Another object of the present invention is to provide a backlight device for a display in which light emission of each light emitting diode channel for providing a backlight can be maintained for one frame.

Another object of the present invention is to provide a backlight device for a display capable of dividing light emitting diode channels of a backlight board into a plurality of control units and controlling driving currents of the light emitting diode channels for each control unit.

Another object of the present invention is to provide a backlight device for a display in which current deviation for a channel of a light emitting diode is improved, a method for compensating for a current deviation of the backlight device, and a compensation circuit.

Another object of the present invention is to provide a backlight device for a display in which a current deviation caused by an input offset voltage for a light emitting diode channel, which acts relatively large in a low current band, is resolved, a method for compensating for a current deviation of the backlight device, and a compensation circuit. is in

The present invention provides a method for compensating for a current deviation of a backlight device for a display, comprising: a first step of extinguishing all light emitting blocks of a backlight board and measuring a total leakage current; a second step of calculating partial leakage currents for the remaining light emitting blocks except for one light emitting block by using the total leakage current; A third step of providing a light-emitting input voltage for light emission of one light-emitting block and measuring the block light-emitting current of the emitted light-emitting block: a pure block light-emitting current obtained by subtracting the partial leakage current from the block light-emitting current a fourth step of calculating a block light emission voltage and estimating an equivalent input voltage corresponding to the pure block light emission voltage value; a fifth step of calculating a current deviation compensation voltage corresponding to a difference between a light emitting input voltage for one block and the equivalent input voltage corresponding to the block light emitting current; a sixth step of generating current deviation compensation data corresponding to the value of the current deviation compensation voltage and storing the current deviation compensation data corresponding to the light-emitting block; and a seventh step of generating and storing the current deviation compensation data of all the light emitting blocks by performing the third to the sixth steps for all the light emitting blocks.

A current deviation compensation circuit of a backlight device for a display according to the present invention includes: a sensing circuit for sensing a current supplied to a plurality of light emitting blocks and providing a digital value for a voltage corresponding to the current; a controller controlling the sensing of the current and generating current deviation compensation data for each light emitting block by using the digital value; and a storage unit for storing the current deviation compensation data for each light emitting block generated by the controller, wherein, in a state in which all of the light emitting blocks are extinguished, the sensing circuit is configured for the all light emitting blocks a first step of controlling to measure the total leakage current; a second step of calculating partial leakage currents for the remaining light emitting blocks except for one light emitting block by using the total leakage current; A third step of controlling the sensing circuit to measure the block emission current of the emitted light emitting block in a state in which the one light emitting block emits light by providing a light emitting input voltage: subtracting the partial leakage current from the block light emitting current a fourth step of calculating a pure block light emission voltage corresponding to one pure block light emission current and estimating an equivalent input voltage corresponding to the pure block light emission voltage value; a fifth step of calculating a current deviation compensation voltage corresponding to a difference between a light emitting input voltage for one block and the equivalent input voltage corresponding to the block light emitting current; a sixth step of generating current deviation compensation data corresponding to the value of the current deviation compensation voltage and storing the current deviation compensation data in the storage unit in response to the light-emitting block; and a seventh step of generating the current deviation compensation data of all the light emitting blocks by performing the third to sixth steps for all the light emitting blocks and storing the data in the storage unit.

In addition, a backlight device for a display of the present invention includes: a backlight driving board having a storage unit for storing current deviation compensation data, and providing column data for a backlight of the display; and a backlight board providing the backlight and having a plurality of light emitting blocks divided into a plurality of control units and current control circuits corresponding to the plurality of control units, wherein the current deviation compensation data is set for each light emitting block a value for compensating for a current deviation, the backlight driving board outputs the column data compensated for each light emitting block as the current deviation compensation data, and each of the current control circuits belongs to the control unit and the current deviation The light emitting input voltages corresponding to the compensated column data are sequentially received, and the sequential light emission of the light emitting blocks belonging to the control unit is controlled using the light emitting input voltages.

In addition, the backlight device for a display according to the present invention includes a backlight driving board for providing column data for the backlight of the display; and a backlight board having a storage unit for storing current deviation compensation data, a plurality of light emitting blocks for providing the backlight, divided into a plurality of control units, and current control circuits corresponding to the plurality of control units; The current deviation compensation data includes a value for compensating for a current deviation set for each light emitting block, and the backlight driving board receives the current deviation compensation data from the storage unit and stores the column data compensated by the current deviation compensation data. output, and each of the current control circuits sequentially receives the light emitting input voltages belonging to the control unit and corresponding to the column data for which the current deviation is compensated, and, as the light emitting input voltages, the light emitting blocks belonging to the control unit. It is characterized in that sequential light emission is controlled.

In addition, the backlight device for a display according to the present invention includes a backlight driving board for providing column data for the backlight of the display; and a backlight board having a storage unit for storing current deviation compensation data, a plurality of light emitting blocks for providing the backlight, divided into a plurality of control units, and current control circuits corresponding to the plurality of control units; The backlight board receives the column data, compensates the column data with the current deviation compensation data of the storage unit, and provides a light emitting input voltage corresponding to the compensated column data, and each of the current control circuits controls the The light emitting input voltages belonging to the unit are sequentially received, and the sequential light emission of the light emitting blocks belonging to the control unit is controlled by the light emitting input voltages.

The present invention may provide a backlight to the display panel, and the driving current of the LED channels may be controlled to maintain light emission for one frame by the sampling voltage of the column signal. Therefore, the present invention can sufficiently maintain the light emission of the light emitting diode channels for the backlight, thereby reducing or eliminating flicker.

In addition, the present invention divides the light emitting diode channels of the backlight board into a plurality of control units, and includes a current control circuit for each control unit. Therefore, according to the present invention, driving currents for light emission can be controlled for each control unit, and the design and manufacture of a backlight board for controlling driving currents of light emitting diode channels can be facilitated by application of the current control circuit.

In addition, the present invention can improve gray uniformity and dark uniformity evaluated in the low current band by resolving the current deviation of the light emitting diode channel due to the input offset voltage, which may act relatively large in the low current band.

Also, according to the present invention, the light emitting diode channels of the backlight device can emit light by compensating for the current deviation due to the input offset voltage by storing the current deviation compensation data in the storage unit and compensating the column data with the current deviation compensation data.

1 is a block diagram illustrating a partial configuration of a backlight board included in an embodiment of a backlight device for a display of the present invention.
Fig. 2 is a block diagram illustrating the current control circuit of Fig. 1;
3 is a block diagram illustrating an electrical connection relationship between a current control circuit and light emitting diode channels;
4 is a diagram illustrating arrangement of light emitting diode channels and control units;
5 is a diagram illustrating brightness of a column signal applied to channels of a light emitting diode;
Fig. 6 is a waveform diagram for explaining an example of the operation of the current control circuit;
7 is a detailed block diagram showing an example of a current control circuit.
8 is a circuit diagram for explaining a current deviation.
9 is a circuit diagram for explaining a method of compensating for a current deviation.
10 is a circuit diagram illustrating a method of generating current deviation compensation data using a compensation circuit;
11 is a flowchart illustrating a method of compensating for a current deviation of a backlight device for a display according to the present invention.
12 is a circuit diagram for explaining measuring the total leakage voltage.
Fig. 13 is a circuit diagram for explaining measuring a block light-emitting voltage;
14 is a block diagram illustrating an embodiment of a backlight device for a display according to the present invention.
15 is a detailed block diagram of a display board, a backlight driving board, and a backlight board of FIG. 12;
16 is a detailed block diagram illustrating an example of the column driver of FIG. 15;
17 is a detailed block diagram illustrating an example of the row driver of FIG. 15;
18 is a block diagram illustrating another embodiment of a backlight device for a display according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms used in the present specification and claims are not limited to a conventional or dictionary meaning, and should be interpreted in a meaning and concept consistent with the technical matters of the present invention.

The embodiments described in this specification and the configurations shown in the drawings are preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents and modifications that can replace them at the time of the present application there may be

The backlight device for a display of the present invention provides a backlight to a display panel for displaying an image, and is implemented to include a backlight board for providing the backlight.

The backlight board of the present invention is implemented to have current control circuits to reduce or eliminate flicker caused by the backlight.

The above-described embodiment of the backlight device of the present invention may be understood with reference to FIG. 14 to be described later. Referring to FIG. 14 , a display device for displaying an image may be exemplified as including a display board 2 , a display panel 4 , a backlight driving board 6 , and a backlight board 40 .

An embodiment of the backlight device of the present invention may be understood to include a configuration for providing a backlight to the display panel 4 . That is, it can be understood that the backlight device of the present invention basically includes the backlight board 40 , and additionally it can be understood that it further includes at least one of the backlight driving board 6 and the display board 2 . have.

In order to understand the present invention, the configuration of the backlight board 40 basically included in the backlight device among the components included in the display device of the present invention will be described first.

The backlight board 40 may be implemented as shown in FIG. 1 , and may include a column driver 10 , a row driver 20 , light emitting diode channels, and current control circuits.

Here, the region in which the LED channels and current control circuits are formed may be defined as the backlight region 30 , and the column driver 10 and the row driver 20 may be formed outside the backlight region 30 . .

Also, in FIG. 1 , the LED channels are denoted by “CH11 to CH93”, and the current control circuits are denoted by “T11, T12, T13, T21, T22, T23, T31, T32, T33”.

The backlight board 40 of FIG. 1 is to provide a backlight for displaying an image to the display panel 4 , and in FIG. 1 , the backlight region 30 is backlit by light emission of the light emitting diode channels CH11 to CH93. It can be understood as an area that provides

With the above configuration, the backlight board 40 is configured to act as a surface light source by a set of light sources.

The embodiment of FIG. 1 includes light emitting diode channels CH11 to CH93 using LEDs as light sources as light sources. The light emitting diode channels CH11 to CH93 may be arranged in a matrix structure having columns and rows. Each of the light emitting diode channels CH11 to CH93 may be understood to include a plurality of LEDs connected in series, respectively.

According to an embodiment of the present invention, the light emitting diode channels CH11 to CH93 are divided into a plurality of control units, and in the embodiment, the control unit may be defined as including a predetermined number of light emitting diode channels continuously arranged on the same column. can

As an example, it may be defined that all of the LED channels CH11 to CH93 are divided into units of four LED channels consecutively arranged on the same column, and the control unit includes the divided four LED channels. .

That is, the light emitting diode channels CH11, CH21, CH31, CH41, the light emitting diode channels CH51, CH61, CH71, CH81, the light emitting diode channels CH12, CH22, CH32, CH42, the light emitting diode channels CH52 , CH62, CH72, CH82), light emitting diode channels CH13, CH23, CH33, CH43, and light emitting diode channels CH53, CH63, CH73, CH83 are each divided into one control unit.

In addition, the embodiment of the present invention includes current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 corresponding to one for each control unit. That is, the backlight board ( 40) is composed. In addition, the current control circuits T11, T12, T13, T21, T22, T23, T31, T32, and T33 are preferably formed of an integrated circuit.

More specifically, the current control circuit T11 is configured to control the driving currents of the light emitting diode channels CH11, CH21, CH31, and CH41, and the current control circuit T21 is configured to control the light emitting diode channels CH51, CH61, CH71. , CH81, the current control circuit T12 is configured to control the driving currents of the light emitting diode channels CH12, CH22, CH32, CH42, the current control circuit T22 is configured to configured to control the driving currents of the channels CH52, CH62, CH72, and CH82, and the current control circuit T13 is configured to control the driving currents of the light emitting diode channels CH13, CH23, CH33, CH43, The control circuit T23 is configured to control the driving currents of the light emitting diode channels CH53, CH63, CH73, and CH83.

The current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 are configured to receive column signals from the column driver 10 and receive row signals from the row driver 20 . The column signals are denoted by D1, D2, D3 ..., and the row signals are denoted by G1, G2, G3 ....

One backlight board 40 provides a backlight having a resolution determined by all of the light emitting diode channels CH11 to CH93, and is configured such that the brightness is controlled by data corresponding to one frame of the backlight. The data of the frame includes data of a plurality of horizontal periods.

The column driver 10 is configured to provide column signals corresponding to every horizontal period of the backlight. Exemplarily, the column driver 10 provides column signals D1 , D2 , and D3 corresponding to columns of the LED channels in units of a horizontal period. The signal lines to which the column signals D1, D2, and D3 are applied may be referred to as column lines.

The column driver 10 receives column data having a value for expressing brightness, and provides column signals D1, D2, and D3 of voltage level corresponding to the column data.

The row driver 20 is configured to receive the raw data and provide row signals G1, G2, ... G9 corresponding to rows of the light emitting diode channels in units of one frame of the backlight in response to the raw data. The raw signals G1, G2, ... G9 have a preset pulse width and are sequentially provided according to the horizontal period of the backlight. Signal lines to which the raw signals G1, G2, ... G9 are applied may be referred to as row lines.

Each of the current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 receives a column signal and a row signal of a control unit corresponding thereto.

To this end, the current control circuits T11, T21 and T31 share one column line to receive the column signal D1, and the current control circuits T12, T22, T32 to receive the column signal D2 in one column. It shares a line, and shares one column line so that the current control circuits T31 , T23 , T33 receive the column signal D3.

In addition, each of the current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 receives raw signals of a control unit. Current control circuits T11 , T12 , T13 ; T21 , T22 , T23 ; T31 , T32 , and T33 in the same row receive the same row signals and share row lines.

The current control circuits T11, T12, T13, T21, T22, T23, T31, T32, and T33 receive the column signal and the row signal corresponding to the control unit as described above and control the driving currents of the LED channels of the control unit. By controlling the light emission of the light emitting diode channels. Exemplarily, as described above, the current control circuit T11 receives the column signal D1, receives the row signals G1 to G4, and controls the driving currents of the light emitting diode channels CH11, CH21, CH31, and CH41 to emit light. Light emission of the diode channels CH11, CH21, CH31, and CH41 is controlled.

Each of the current control circuits T11, T12, T13, T21, T22, T23, T31, T32, and T33 as described above generates sampling voltages obtained by sequentially sampling column signals for each horizontal period as raw signals. It is possible to control light emission and maintenance of brightness of the light emitting diode channels of the control unit. Exemplarily, the current control circuit T11 generates sampling voltages by sampling the column signal D1 for each horizontal period as row signals G1 to G4 for each horizontal period that are sequentially provided, and belongs to the same control unit by the sampling voltages. Driving currents for light emission of the light emitting diode channels CH11, CH21, CH31, and CH41 are controlled.

In addition, each of the current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 may receive a zoom control signal CZ for controlling a driving current. A description of the zoom control signal CZ will be described later.

Each of the current control circuits T11 , T12 , T13 , T21 , T22 , T23 , T31 , T32 , and T33 configured in FIG. 1 described above may be specifically illustrated as in FIG. 2 . 2 illustrates a current control circuit T11.

The current control circuit T11 may be configured as an integrated circuit as shown in FIG. 2 .

The current control circuit T11 of FIG. 2 includes a column input terminal TD1, row input terminals TG1 to TG4, a zoom input terminal TCZ, a monitor terminal TMON, a ground terminal TGND, an operating voltage terminal TVCC, A feedback stage TFB and control stages T01 to T04 may be provided. Here, the column input terminal TD1 receives the column signal D1, the row input terminals TG1 to TG4 receive the row signals G1 to G4, and the zoom input terminal TCZ receives the zoom control signal CZ, and the monitor The terminal TMON outputs the monitor signal MON, the ground terminal TGND is connected to the ground GND, the operating voltage terminal TVCC receives the operating voltage VCC, and the feedback terminal TFB is a feedback signal FB is output, and the control terminals TO1 to TO4 receive driving currents O1 to O4 of the light emitting diode channels CH11, CH21, CH31, and CH41.

Electrical connection between the current control circuit T11 of FIG. 2 and the LED channels CH11, CH21, CH31, and CH41 corresponding to the control unit may be understood with reference to FIG. 3 .

The emission voltage VLED is applied to each of the LED channels CH11, CH21, CH31, and CH41, and includes a plurality of LEDs connected in series. Low-side driving currents O1 to O4 of each of the LED channels CH11, CH21, CH31, and CH41 are input to the current control circuit T11.

The configuration of the remaining current control circuits T12, T13, T21, T22, T23, T31, T32, and T33 may also be understood with reference to FIGS. 2 and 3 .

Meanwhile, FIG. 4 illustrates the arrangement of the LED channels and the division of control units. 4 shows a control unit C11 including light emitting diode channels CH11, CH21, CH31, and CH41, a control unit C12 including light emitting diode channels CH12, CH22, CH32, CH42, and a light emitting diode channel A control unit C13 including the channels CH13, CH24, CH34, CH44 and a control unit C14 including the light emitting diode channels CH14, CH24, CH34, CH44 are exemplified.

One column signal and four row signals are input to each control unit. In addition, column signals applied to respective light emitting diode channels may be provided to have voltage levels for brightness as shown in FIG. 5 .

More specifically, FIG. 5 shows that column signals D1, D2, D3, and D4 are provided at a level of “4, 5, 1, 2” in the first horizontal period in which the raw signal G1 is provided, and in the second horizontal period in which the raw signal G2 is provided. It is exemplified that it is provided at the level of “3, 1, 5, 5” in the horizontal period. Here, the level value of FIG. 5 may be understood as an exemplary value for expressing an amplitude rather than an actual voltage level. And, the value of the column signal is exemplified to be expressed between 8 levels divided into a range of 0 and 7. The value of the column signal may be expressed at various levels according to the resolution for expressing the brightness, and for example, may be expressed with a resolution such as 16 levels, 32 levels, or 64 levels.

An embodiment of the present invention can be operated by column signals and raw signals provided as shown in FIGS. 4 and 5, and it is shown in FIG. 6 that a column signal is sampled by raw signals according to an embodiment of the present invention. can be understood by reference.

In FIG. 6 , FR1 and FR2 indicate a frame period of the backlight, HL1 to HL4 indicate a horizontal period of the backlight, D1 indicates a column signal, and G1 to G4 indicates a raw signal. And, “4, 3, 1, 5” of the column signal D1 indicates the level, ie, the amplitude, of the column signal shown in FIG. 5 .

In this case, the embodiment of the present invention controls the driving current by the level, that is, the amplitude of the column signal that is a pulse, which is that the driving current is controlled by pulse amplitude modulation (hereinafter, referred to as “PAM”). can be understood

6 is a waveform diagram illustrating an operation of a current control circuit according to PAM.

Referring to FIG. 6 , the column signal D1 is provided to the current control circuit T11 at level “4” in the horizontal period HL1 of the frame FR1, and the raw signal G1 is set at the level for sampling (exemplarily “high” in the horizontal period HL1). ") is provided. In this case, the current control circuit T11 generates a sampling voltage obtained by sampling a column signal having a level “4” using the raw signal G1, and a driving current O1 having a level “4” corresponding to the level of the sampling voltage for light emission. It is controlled so that it flows through this light emitting diode channel (CH11). The sampling voltage of the current control circuit T11 is maintained until the horizontal period HL1 of the next frame FR2. Therefore, the current control circuit T11 maintains the driving current O1 of the light emitting diode channel CH11 of level "4" until the horizontal period HL1 of the next frame FR2.

The column signal D1 is changed to levels "3", "1" and "5" The current control circuit T11 generates a sampling voltage by sampling the column signal using the raw signals G2, G3, and G4 sequentially provided for each horizontal period, and driving currents O2 and O3 corresponding to the level of the sampling voltage for light emission. , to control O4 to flow.

The sampling voltages generated using the respective raw signals G2, G3, and G4 of the current control circuit T11 are maintained until the horizontal periods HL2, HL3, HL4 of the next frame FR2. Therefore, the current control circuit T11 maintains the levels of the driving currents O2, O3, and O4 of the light emitting diode channel CH11 to maintain the brightness of the level corresponding to the column signal D1 of each horizontal period until the next frame FR3.

In addition, the sampling voltages sampled by each row signal G2, G3, and G4 of the current control circuit T11 are maintained for one frame period as described above and are reset to have a level corresponding to the current column signal in units of frame periods. can be understood as

That is, the current control circuit T11 generates sampling voltages for each of the light emitting diode channels CH11, CH21, CH31, and CH41 in response to the column signal D1 and the row signals G1 to G4, and uses the sampling voltages to generate each light emission. Controls the driving current between the control terminals TO1 to TO4 corresponding to the low side of the diode channels CH11, CH21, CH31, and CH41 and the ground GND.

For the above-described operation, the current control circuit T11 may be implemented as shown in FIG. 7 .

Referring to FIG. 7 , the current control circuit T11 includes a buffer BF, driving current control units 101 to 104 , a feedback signal providing unit 300 , a monitor signal providing unit 400 , and a temperature detecting unit 500 . is configured to include

The buffer BF receives the column signal D1 through the column input terminal TD1 and is configured to provide the received column signal D1 to the driving current controllers 101 to 104 in common. The buffer BF is exemplified as being commonly configured to the driving current controllers 101 to 104, but may be designed to be mounted inside each of the driving current controllers 101 to 104.

Each of the driving current controllers 101 to 104 generates a sampling voltage VC by sampling the column signal D1 as the raw signal G1 to G4 of the corresponding light emitting diode channel, and is connected to the control terminals TO1 to TO4 using the sampling voltage VC. It is configured to control the driving currents O1 to O4 of the light emitting diode channels CH11, CH21, CH31, and CH41.

By referring to the driving current control unit 101 as a representative, the configuration and operation of the driving current control units 101 to 104 will be described. The configuration of the driving current controllers 102 to 104 may be understood to be the same as that of the driving current controller 101 .

First, the driving current control unit 101 is configured to receive the column signal D1, the raw signal G1, the temperature detection signal TP, and the zoom control signal CZ, and control the driving current O1.

The driving current controller 101 includes an internal circuit 200 and a channel detector 210 .

In the case of FIG. 7 , the internal circuit 200 includes a holding circuit 202 and a channel current controller 204 .

The holding circuit 202 is configured to generate a sampling voltage VC that has sampled the column signal D1 as the raw signal G1, and hold the sampling voltage VC. To this end, the holding circuit 202 includes a switch SW that switches the transmission of the column signal D1 by the raw signal G1 and a capacitor C that generates a sampling voltage VC that samples the column signal D1 transmitted through the switch SW. ) is included. The capacitor C performs sampling to charge the column signal D1 transmitted through the switch SW while the raw signal G1 is enabled, and stores and generates a sampling voltage VC corresponding to the sampling result. In addition, the capacitor C may provide the sampling voltage VC to the channel current controller 204 while maintaining the sampling voltage VC.

The channel current controller 204 is configured to control the amount of the driving current O1 for light emission of the light emitting diode channel CH11 connected to the control terminal TO1 by using the sampling voltage VC of the capacitor C. Referring to FIG. The channel current controller 204 may be configured to have a dependent current source gm that controls the flow of the driving current O1 to have an amount controlled to the level of the sampling voltage VC. In addition, the dependent current source gm may receive the temperature detection signal TP and the zoom control signal CZ, and the flow of the driving current is blocked by the temperature detection signal TP or the amplified driving current flows according to the level of the zoom control signal CZ. It can be configured to

Meanwhile, the channel detector 210 may be configured to provide the first detection signal CD1 and the second detection signal CD2 by detecting a voltage between the control terminal TO1 and the ground GND.

Here, the first detection signal CD1 determines whether the voltage between the control terminal TO1 and the ground GND is equal to or less than the first level, and the second detection signal CD2 is the voltage between the control terminal TO1 and the ground GND. It is judged whether it is lower than the 2nd level lower than this 1st level. The first detection signal CD1 and the second detection signal CD2 may be provided to have a high level when a condition is satisfied.

The driving current O1 may be decreased when the emission voltage VLED applied to the light emitting diode channel CH11 is lower than the lowest emission voltage. Therefore, when the emission voltage VLED is regulated to be equal to or higher than the minimum emission voltage, the driving current O1 is also regulated, and as a result, the brightness of the LED channel CH11 may be constantly maintained. The detection signal CD1 is for the regulation of the above-described driving current O1, and is activated to a high level when the voltage between the control terminal TO1 and the ground GND is lowered to a preset level (eg, 0.5V) or less. can be provided. The first detection signal CD1 may be provided to the feedback signal providing unit 300 .

When an open or short occurs in the light emitting diode channel CH11, the driving current O1 may be blocked or an abnormally large amount may flow. In this case, when the voltage between the control terminal TO1 and the ground GND is lowered to a preset level (eg 0.2V) lower than the first level, the second detection signal CD2 is activated to a high level to be provided. can The second detection signal CD2 may be provided to the monitor signal providing unit 400 .

Meanwhile, the feedback signal providing unit 300 controls the feedback signal FB by controlling the current between the feedback terminal TFP and the ground GND in response to each of the first detection signals CD1 of the driving current control units 101 to 104 . is configured to

To this end, the feedback signal providing unit 300 may include an OR gate and a current driving transistor, and the OR gate is current driven in response to at least one of the first detection signals CD1 of the driving current control units 101 to 104 . for controlling the gate of the transistor, the current driving transistor may control the feedback signal FB to a low level in response to the high level output of the OR gate and control the feedback signal FB to a high level in response to the low level output of the OR gate have.

That is, the feedback signal providing unit 300 may control the feedback signal FB to a low level when the driving current of at least one of the driving current controllers 101 to 104 is lower than a preset level.

In addition, the temperature detection unit 500 is configured to provide a temperature detection signal TP sensing the temperature of the current control integrated circuit T11 configured as a chip. For example, when the current control integrated circuit T11 rises to a temperature greater than or equal to a preset temperature, the temperature detection unit 500 may provide the temperature detection signal TP activated to a high level.

When the temperature detection signal TP is activated by the temperature detection unit 500 detecting a temperature greater than or equal to a preset temperature, the current flow of the dependent current source gm is blocked by the activated temperature detection signal TP. Conversely, when the temperature detection signal TP is deactivated by the temperature detection unit 500 detecting a temperature lower than a preset temperature, the current flow of the dependent current source gm is not affected by the temperature detection signal TP. The temperature detection unit 500 protects the integrated circuit and the backlight device from overheating by controlling to block or release the driving current flowing through the light emitting diode channel.

In addition, the monitor signal providing unit 400 receives the second detection signals CD2 and the raw signals G1 to G4 of the driving current controllers 101 to 104 , and receives the raw signal of the at least one driving current controller 104 and It is configured to control the monitor signal MON by controlling the current between the monitor terminal TMON and the ground GND when the second detection signal CD2 is in the active state of the high level.

Also, the monitor signal providing unit 400 is configured to control the monitor signal MON by controlling the current between the monitor terminal TMON and the ground GND according to the temperature detection signal TP.

To this end, the monitor signal providing unit 400 may include an OR gate circuit and a current driving transistor. Here, the OR gate circuit may be configured to turn on the current driving transistor when the raw signal of the at least one driving current controller and the second detection signal CD2 are in an activated state at a high level or when the temperature detection signal TP is in an activated state at a high level. have. To this end, the OR gate circuit includes first NAND gates comparing the raw signal of each driving current controller 101 to 104 with the second detection signal CD2, a second NAND gate comparing outputs of the first NAND gates, and a second An OR gate may be provided that orally combines the output of the NAND gate and the temperature detection signal TP. Since the above-described OR gate circuit may be variously implemented by a manufacturer, a detailed description of the configuration and operation of the drawings will be omitted. In addition, the current driving transistor may be configured using an NMOS transistor.

According to the above configuration, the monitor signal providing unit 400 controls the corresponding driving current control units 101 to 104 when at least one of the raw signals G1 to G4 among the driving current control units 101 to 104 is enabled at a high level. ) of the second detection signal CD2 is activated to a high level, the monitor signal MON may be controlled to a low level by turning on the current driving transistor. Also, when the temperature detection signal TP is activated to a high level, the monitor signal providing unit 400 may control the monitor signal MON to a low level by turning on the current driving transistor.

The above-described monitor signal MON may be provided to a timing controller (not shown) or a separate application, and thus may be used to control the backlight device during abnormal operation.

On the other hand, the zoom control signal CZ is for controlling the resolution of the low driving current region of the light emitting diode channel controlled by the sampling voltage VC. It may be understood that when the resolution of the driving current is increased by the zoom control signal CZ, the resolution of the brightness that can be expressed by the driving current is increased.

The zoom control signal CZ may be provided outside the current control circuit T11.

The zoom control signal CZ may be provided as the same value to all of the LED channels of the backlight board 40 or the LED channels of the control unit.

Also, the zoom control signal CZ may be provided for each light emitting diode channel to have a value corresponding to data for light emission, ie, a column signal for each light emitting diode channel.

In addition, the brightness range expressed by the column signal may be divided into a high current region that is brighter than a predetermined reference brightness and a current region that is lower than the reference brightness, and the zoom control signal CZ is different for a high current region and a low current region. It can be provided as a value.

That is, the zoom control signal CZ may be provided to have a value for controlling the driving current so that the low current region has a higher resolution than the high current region.

For example, the zoom control signal CZ may be provided as 0V with respect to a driving current of 10 mA or more having a high brightness level, and the zoom control signal CZ may be provided as 5V with a driving current of less than 10 mA having a low brightness level. When the zoom control signal CZ is provided as 0V, the driving current may be controlled in the basic current range corresponding to the basic voltage range of the column signal D. In addition, when the zoom control signal CZ is provided as 5V, the driving current may be finely controlled to a driving current ranging from 0 mA to 10 mA in a voltage range wider than the basic voltage range of the column signal D. That is, when the zoom control signal CZ is provided as 5V, the amount of the low-brightness driving current can be more finely controlled to have a high resolution.

As described above, the zoom control signal CZ has a value for controlling to have a first resolution with respect to a driving current corresponding to a current region greater than or equal to a predetermined standard, and has a value higher than the first resolution for a driving current corresponding to a current region less than the reference. It may be provided to have a value controlling to have the second resolution.

That is, the resolution of the expression range of the brightness of a specific driving current may be increased by the zoom control information CZ.

1 to 7, the brightness level of the light emitting diode channel can control the driving current of the light emitting diode channel according to the level, that is, the amplitude of the column signal.

An operation of the backlight board 40 of the backlight device of the present invention can be understood by the above description of FIGS. 1 to 7 .

The backlight device of the present invention may include a plurality of backlight boards 40 for providing a backlight, and each backlight board 40 includes a plurality of current control circuits and a plurality of light emitting diode channels.

Then, the column signal is input to the current control circuit of the backlight board 40, and the light emitting diode channel emits light to have brightness according to the current control of the current control circuit corresponding to the column signal.

All light emitting diode channels should emit light to have the same brightness for the same column data. However, the brightness of the LED channels may vary with respect to the same column data due to a current deviation.

Hereinafter, for convenience of description, a column signal corresponding to column data may be understood as a light emission driving voltage VD, and ultimately, a light emission input voltage Dout may be described as being input to the current control circuit of the backlight board 40 . .

The current deviation is equivalent to generating an input offset voltage on a path through which the light emitting input voltage Dout of the backlight board 40 is transmitted, or an equivalent generating an input offset voltage inside the current control circuit T11 including the buffer BF. It can be understood as occurring due to an enemy configuration or the like.

The above-described input offset voltage may be formed differently for each light emitting diode channel, and acts as a cause of causing a current deviation with respect to the current for light emission of the light emitting diode channels of the backlight board 40 . As a result, the LED channels may emit light with different brightness corresponding to the same column data.

The current deviation for each LED channel generated for the above reason may have a relatively greater effect than the high current band when the driving of the LED channel is controlled by the current in the low current band. That is, the above-described current deviation may have a greater effect on the brightness of the LED channel for the current of the low current band than the current of the high current band.

The present invention discloses an embodiment for compensating for the above-described current deviation.

A light emitting block may be defined for the description of the present invention. The light emitting block is a basic unit for controlling dimming, and may be understood to include at least one light emitting diode channel included in a preset zone on the backlight board 40 . The embodiment of the present invention is exemplified as one light emitting diode channel forming one light emitting block for convenience of description. In the example above, the light emitting diode channel is described as a block of light. And, it may be understood that the light emitting blocks have the above-described current deviation.

The current deviation is calculated by calculating the input offset voltage that affects the light emitting current for each light emitting block and compensating the column data to be provided to the light emitting block, that is, the light emitting input voltage Dout as current deviation compensation data having a value corresponding to the input offset voltage. can solve

A method of compensating for the above-described current deviation will be described in detail with reference to FIGS. 8 and 9 .

8 and 9 , the light emitting block CH11, the current control circuit T11, and the dimming voltage control unit DVT are exemplified.

The dimming voltage controller DVT corresponds to a configuration that provides a column signal and a ROW signal, and the column signal is indicated by a light emitting input voltage "Dout" by the light emission driving voltage VD, and the ROW signal is indicated by "G1". For example, it may be understood to correspond to one of the column driver 10 of FIG. 1 , the column driver 10 of FIGS. 15 and 18 , the communication module 42 , and the controller 60 .

The dimming voltage control unit DVT is briefly and equivalently illustrated as including the light emission driving voltage VD for the purpose of explaining a current deviation and a method of compensating the same.

The current control circuit T11 includes a buffer BF and a driving current control unit 101 , and the driving current control unit 101 includes a holding circuit 202 and a channel current circuit 204 , and a channel current circuit 204 . ) is shown including the dependent current source gm. The above-described current control circuit T11, driving current control unit 101, holding circuit 202, and channel current circuit 204 are schematically illustrated equivalently, and the specific configuration and operation will be understood with reference to FIG. can

The buffer BF is exemplified as an internal offset voltage DTH for the purpose of quenching or the like is formed on a negative input terminal (-) and an input offset voltage Voffset is formed on a positive input terminal (+).

Therefore, the voltage applied to the positive input terminal (+) of the buffer BF can be expressed as the equivalent input voltage DCH. In FIG. 8 , it may be understood that the equivalent input voltage DCH corresponds to a value obtained by subtracting the light emitting input voltage Dout by the input offset voltage Voffset.

The block light emitting current iLED includes a leakage current, and the pure block light emitting current iLED_CH used for light emission of the light emitting block CH11 can be seen as having removed the effect of the leakage current.

And, the relationship between the pure block light emitting current iLED_CH and the equivalent input voltage DCH can be defined as in Equation 1 below.

In Equation 1, Dmax is the maximum value of the light emission input voltage Dout, and iLEDmax is the maximum value of the block light emission current iLED. Here, the maximum value Dmax of the light emission input voltage DOUT, the maximum value iLEDmax of the block light emission current iLED, and the internal offset voltage DTH are known values.

And, an equation for obtaining the equivalent input voltage DCH can be derived as shown in Equation 2 below using Equation 1 above.

A current deviation for each light emitting block may also occur due to a difference in internal characteristics (eg, a gain difference) of components included in the holding circuit 202 and the channel current circuit 204 in the driving current controller 101 . The pure block light emission current iLED_CH has an amount controlled by the driving current controller 101 . Therefore, it can be understood that the current deviation due to the difference in the internal characteristics of the driving current controller 101 is reflected in the pure block light emitting current iLED_CH.

The input offset voltage Voffset may vary for each light emitting block. That is, each light emitting block has a deviation of the input offset voltage Voffset, and has a current deviation due to the deviation of the input offset voltage Voffset with respect to the same light emitting input voltage Dout.

The above-described current deviation for each light emitting block can be resolved by removing the input offset voltage Voffset for each light emitting block.

That is, as shown in FIG. 9 , when the dimming voltage control unit DVT is configured to have a current deviation compensation voltage Doffset at the same level as the input offset voltage Voffset, the input offset voltage Voffset of the current control circuit T11 is the dimming voltage control unit DVT ) can be removed by As a result, the current deviation for each light emitting block can be resolved.

The current deviation compensation voltage Doffset may be set by estimating the input offset voltage Voffset, and the input offset voltage Voffset may be estimated by measuring the current flowing for each light emitting block. The estimated input offset voltage Voffset may be set to have the same value as the current deviation compensation voltage Doffset.

Measurement of the input offset voltage Voffset for each light emitting block may be described using FIG. 10 .

10 illustrates a compensation circuit 700 for estimating an input offset voltage Voffset.

In FIG. 10 , the light emitting blocks CH11 , CH12 , CH13 , and CH14 belong to one control unit and are connected to the current control circuit T11 , and may be understood to represent the entire light emitting block. VLED indicates a light-emitting voltage applied to all light-emitting blocks, and may be understood as a reference voltage of a level to be set in advance for measurement.

The compensation circuit 700 includes a sensing circuit 710 and a controller 720 .

The sensing circuit 710 includes a resistor R, a buffer SB, a switch SWC, and an analog-to-digital converter (hereinafter, referred to as ADC) 712 .

A resistor R is configured on a current path that supplies current to all light emitting blocks.

The buffer SB has a first input terminal and a second input terminal connected to both ends of the resistor R, and a current-to-voltage conversion for outputting a voltage corresponding to a potential difference between both ends of the resistor R, that is, a current flowing through the resistor R is a circuit

The switch SWC is configured to selectively form a bypass path for the resistor R. When sensing is unnecessary, the switch SWC is turned on to provide a current path bypassing the resistor R, and is turned off when sensing is required to form a current path through the resistor R.

The ADC 712 is for converting the level of the voltage output from the buffer SB into a digital value.

The controller 720 is configured to provide a control signal for controlling a switching state to the switch SWC for current sensing control.

Then, the controller 720 receives the digital value provided from the ADC 712 , and uses it to perform a process of estimating the current deviation compensation data for resolving the current deviation, and outputs the current deviation compensation data generated as a result of the process is configured to

The storage unit DCM is to store the current deviation compensation data provided from the controller 720 .

In the above configuration, the compensation circuit 700 may be configured in a test facility used for testing after manufacturing the backlight board 40 , and the storage unit DCM may be understood as a memory of the test facility.

In this case, the storage unit DCM may store the current deviation compensation data for each light emitting block in the form of a look-up table. In addition, the lookup table of the storage unit DCM is initialized before the test, and after the test is completed, a separate storage unit (DCM of FIG. 15 or FIG. 18 ) mounted on the backlight board 40 or the backlight driving board 6 ) can be stored in

In addition, some or all of the compensation circuit 700 and the storage unit DCM may be mounted on the backlight board 40 or the backlight driving board 6 configured in the backlight device for the display of the present invention.

In this case, the controller 720 of the compensation circuit 700 may generate current deviation compensation data for each light emitting block at a preset time point and update the current deviation compensation data in the storage unit DCM. The preset time point may be exemplarily understood as a power-on system initialization time of the display.

In the embodiment of the present invention, the controller 720 of the compensation circuit 700 may be understood to correspond to the controller 60 of FIG. 15 or FIG. 18 to be described later. In this case, only the sensing circuit 710 of the compensation circuit 700 is mounted on the backlight board 40 or the backlight driving board 6 , and the current deviation compensation data is converted to the current deviation by the controller 60 of FIG. 15 or 18 . It may be updated in the compensation data storage unit DCM.

In addition, the controller 720 may be configured separately from the controller 60 of FIGS. 15 and 18 according to the intention of the manufacturer.

A method of generating current deviation compensation data for each light emitting block using the above-described compensation circuit 700 may be described with reference to FIGS. 11 to 13 .

The lookup table data of the current deviation compensation data storage unit DCM is in an initialized state in which the current deviation compensation voltage Doffset is 0 V before being updated through the first current deviation compensation process.

The flowchart of FIG. 11 is a step-by-step description of a method of generating current deviation compensation data.

The block light-emitting current iLED supplied to the light-emitting block CH11 that emits light includes a leakage current. Therefore, in order to accurately compensate the current deviation for the light emitting block CH11, the leakage current included in the block light emitting current iLED must be removed. In this case, the leakage current corresponds to a current provided to the light emitting blocks CH12 to CH14 other than the light emitting block CH11.

To this end, the step S10 of measuring the total leakage current iLEDOFF and the step S12 of generating the partial leakage current iLEDOFFm of the light emitting blocks CH12 to CH14 other than the light emitting block CH11 using the measured total leakage current iLEDOFF will be performed. can

12 is a circuit diagram illustrating measuring the total leakage current iLEDOFF in step S10.

The controller 720 controls the switch SWC to maintain the turn-on state in a normal state, and controls the switch SW to be turned off during a period of sensing the total leakage current iLEDOFF to perform step S10.

Then, in order to perform step S10, all of the light emitting blocks CH11 to CH14 are extinguished, and at this time, the light emission input voltage Dout and the row signals G1 through the light emission driving voltage VD provided by the dimming voltage controller DVT It can be understood that G4 is all in an inactive state.

When the light emitting voltage VLED is applied to all the quenched light emitting blocks CH11 to CH14, the total leakage current iLEDOFF may flow through all the light emitting blocks CH11 to CH14.

The total leakage current iLEDOFF flows through the resistor R, and the buffer SB senses and outputs the voltage applied to the resistor R. That is, the buffer SB outputs the total leakage voltage VLEDOFF corresponding to the total leakage current iLEDOFF.

The ADC 712 generates total leakage data having a digital value corresponding to the measured total leakage voltage VLEDOFF, and the controller 720 temporarily stores the total leakage data of the ADC 712 .

Thereafter, a partial leakage voltage VLEDOFFm may be generated in step S12 using the total leakage voltage VLEDOFF generated in step S10 by the controller 720 .

The partial leakage voltage VLEDOFFm corresponds to the partial leakage current iLEDOFFm flowing to the other light emitting blocks except for one light emitting block.

The total leakage current iLEDOFF corresponds to the sum of the leakage currents flowing through all the light emitting blocks CH11 to CH14.

The partial leakage current iLEDOFFm flowing to the other light emitting blocks except for one light emitting block may be generated by Equation 3 below.

In Equation 3, N is the total number of light emitting blocks.

The partial leakage voltage VLEDOFFm may be generated as in Equation 4 below using the relationship between the total leakage current iLEDOFF and the partial leakage current iLEDOFFm.

The controller 720 may generate and store partial leakage voltage data corresponding to the partial leakage voltage VLEDOFFm by using the temporarily stored total leakage data using the relationship of Equation 4 above.

When one light emitting block emits light, a leakage current included in the block light emitting current iLED may be calculated by the above-described steps S10 and S12.

After generating and storing partial leakage voltage data corresponding to the partial leakage voltage VLEDOFFm as described above, the controller 720 may perform step S14 of measuring the block emission voltage VS of one light emitting block that is emitted.

In step S14, one light-emitting block is emitted by providing the light-emitting input voltage Dout, and the block light-emitting voltage VS of the emitted light-emitting block is measured.

13 is a circuit diagram illustrating measurement of the block emission voltage VS of one light emitting block in step S14. 13 illustrates that only the light-emitting block CH11 emits light and the remaining light-emitting blocks CH12, CH13, and CH14 are extinguished.

The controller 720 turns off the switch SWC during a period for sensing the block light emitting current iLED of one light emitting block to perform step S14.

In this case, light emission or extinction of the light emitting blocks CH11 , CH12 , CH13 , and CH14 may be controlled by a corresponding ROH signal and a light emission input voltage Dout. More specifically, it may be understood that the light emitting input voltage Dout is activated to have a preset level for testing. The lookup table data of the current deviation compensation data storage unit DCM is in an initialized state in which the current deviation compensation voltage Doffset is 0 V before being updated through the current deviation process for the first time. Therefore, the light emission input voltage Dout becomes the light emission driving voltage VD.

The raw signal G1 may also be activated to correspond to the time when the switch SWC is turned on. It can be understood that all of the remaining raw signals G2 to G4 are in an inactive state.

When only the light emitting block CH11 emits light, the block light emitting current iLED may be defined as including the pure block light emitting current iLED_CH and the partial leakage current iLEDOFFm as shown in Equation 5 below.

Using Equation 5 above, the pure block light emitting current iLED_CH can be defined as Equation 6 below.

When only the light-emitting block CH11 emits light, the block light-emitting current iLED flows through the resistor R, and the buffer SB senses and outputs the voltage applied to the resistor R. That is, the buffer SB outputs the block light emission voltage VS corresponding to the block light emission current iLED.

The block emission voltage VS output from the buffer SB may be defined as in Equation 7 below.

In Equation 7, RS is the resistance value of the resistor R, and K is the gain of the buffer SB.

The ADC 712 generates block emission voltage data having a digital value corresponding to the block emission voltage VS measured as described above, and the controller 720 temporarily stores the block emission voltage data of the ADC 712 .

When the block emission voltage VS is measured as described above, step S16 may be performed.

Step S16 is to generate a pure block light emission voltage VCH in which the influence of the partial leakage voltage VLEDOFFm is removed from the block light emission voltage VS.

The block light emission voltage VS may be understood to include a pure block light emission voltage VCH and a partial leakage voltage VLEDOFFm with reference to Equation 5, and may be defined as Equation 8 below.

Using Equation 8 above, the pure block emission voltage VCH can be defined as Equation 9 below.

The controller 720 uses the block light emission voltage data corresponding to the block light emission voltage VS and the partial leakage voltage data corresponding to the partial leakage voltage VLEDOFFm according to Equation 9 above to obtain pure block light emission voltage data corresponding to the pure block light emission voltage VCH can be created and temporarily stored.

The controller 720 may perform step S18 after generating the pure block light emission voltage VCH as described above.

Step S18 is to generate an equivalent input voltage DCH corresponding to the pure block emission voltage VCH with respect to the emitted light emitting block CH11.

To this end, the controller 720 may generate an equivalent input voltage DCH for the emitted light emitting block CH11 by using the pure block light emission voltage data corresponding to the pure block light emission voltage VCH.

The equivalent input voltage DCH corresponds to the input voltage obtained by resolving the input offset voltage Voffset.

First, the pure block light emission voltage VCH may be defined as in Equation 10 below.

The pure block light emission current iLED_CH can be defined as Equation 11 below by modifying Equation 10 above.

In Equation (11), the pure block light emission voltage VCH is a known value obtained by Equation (9). Therefore, the value of the pure block light emission current iLED_CH is also known.

The equivalent input voltage DCH is defined in Equation 2 above.

In Equation 2, the pure block light emission current iLED_CH is obtained from Equation 11, and the maximum value Dmax of the light emission input voltage DOUT, the maximum value iLEDmax of the block light emission current iLED, and the internal offset voltage DTH are known values.

Therefore, the equivalent input voltage DCH can be generated by Equation (2).

That is, the controller 720 obtains and temporarily stores the pure block light emitting current data corresponding to the pure block light emitting current iLED_CH by Equation 11, and stores an equivalent input voltage with respect to the light emitting block CH11 emitted by Equation 2 It is possible to generate and temporarily store equivalent input voltage data corresponding to the DCH.

Thereafter, the controller 720 may generate a current deviation compensation voltage Doffset by performing step S20.

The current deviation compensation voltage Doffset should be set equal to the input offset voltage Voffset.

Therefore, in order to define the current deviation compensation voltage Doffset, it is necessary to define the light emitting input voltage Dout as in Equation 12 below.

As in Equation 12, the light emission input voltage Dout may be expressed as the sum of the input offset voltage Voffset and the equivalent input voltage DCH of the block.

By Equation 12, the input offset voltage Voffset may be defined as Equation 13 below.

That is, the input offset voltage Voffset may be obtained as a difference between the light emitting input voltage Dout of one block and the equivalent input voltage DCH.

Before the initial current deviation compensation, since the current deviation compensation voltage Doffset is 0V, the light emission input voltage Dout is equal to the light emission driving voltage VD.

Therefore, the input offset voltage Voffset before the initial current deviation compensation may be defined as in Equation 14 below.

In Equation 14, the equivalent input voltage DCH is generated by Equation 2, and the light emission driving voltage VD is a known value.

As a result, the input offset voltage Voffset can be obtained by Equation 14, and the current deviation compensation voltage Doffset must be set equal to the input offset voltage Voffset. As a result, the current deviation compensation voltage Doffset can be calculated as in Equation 15 below.

DCH After that, the controller 720 performs step S22 to generate current deviation compensation data corresponding to the current deviation compensation voltage Doffset and store it in the current deviation compensation data storage unit (DCM) in the form of lookup table data for the light emitting block. have.

The controller 720 may subsequently perform step S24. That is, the controller 720 may generate and store current deviation compensation data for all the light emitting blocks by performing the above-described steps S14 to S22 while emitting light one by one of the remaining light emitting blocks CH12 to CH14.

In this way, the controller 720 may complete the process of storing the current deviation compensation data respectively corresponding to all the light emitting blocks in the storage unit DCM.

The current deviation compensation data for all the light emitting blocks secured as described above may be used to resolve the current deviation acting on all the light emitting blocks configured in the backlight board 40 .

The backlight device for a display according to an embodiment of the present invention may be configured to compensate column data as current deviation compensation data and provide a column signal corresponding to the compensated column data.

In this case, it may be understood that the column signal has a level compensated for by a level corresponding to the current deviation compensation voltage Doffset.

More specifically, the column data may be summed with the current deviation compensation data to compensate for the current deviation, and by the compensated column data, the column signal is set to a level higher by the current deviation compensation voltage Doffset than the level represented by the original column data. can be provided.

When the column signal based on the compensated column data is exemplarily input to the buffer BF of the current control circuit T11, the level of the column signal is subtracted by the input offset voltage Voffset.

As a result, the input offset voltage Voffset acting on the column signal can be canceled by the current deviation compensation voltage Doffset.

Therefore, since the column signal is input to the buffer BF after the influence of the input offset voltage Voffset is canceled, the light emitting blocks can emit light by a current that faithfully corresponds to the column data.

In the present invention, the current deviation compensation data for each light emitting block, that is, look-up table data stored in the storage unit DCM of FIG. 10 is stored in the memory mounted on the backlight board 40 or the backlight driving board 6 . can

According to the present invention, the current deviation for the light emitting diode channel can be improved by compensating column data using the current deviation compensation data. For this purpose, an embodiment of a backlight device for a display will be configured as shown in FIGS. can

For reference, in the description of FIGS. 14 to 18 , the light emitting block may be understood as corresponding to the light emitting diode channel, and the column signal may be understood as corresponding to the above light emitting input voltage Dout.

14 and 15 illustrate an embodiment of configuring the storage unit DCM in the backlight driving board 6 .

14, the display board 2, the display panel 4, the backlight driving board 6 and the backlight board 40 are configured. The embodiment of the backlight device of the present invention basically includes a backlight board 40 , and may additionally include a backlight driving board 6 and a display board 2 .

First, the display panel 4 may be configured using an LCD panel.

The display panel 4 interfaces with the display board 2 through the transmission line 3 , and receives the display data of the display board 2 through the transmission line 3 . The display panel 4 includes pixels (not shown) for implementing a pre-designed resolution, and each pixel performs an optical shutter operation in response to display data, so that an image can be displayed using a backlight.

The display data provided to the display panel 4 includes data for displaying an image in units of frames, for example, data indicating the brightness of a pixel, a horizontal sync signal for dividing a horizontal line, and a frame for dividing a frame It may include a vertical synchronization signal and the like. Among them, the vertical sync signal may be denoted as “Vsync” in the description to be described later.

Meanwhile, the display board 2 receives display data transmitted from a video source (not shown).

The display board 2 may include components (not shown) configured to form display data into packets and provided to the display panel 4 , and may provide display data for displaying an image to the display panel 4 . .

Components configured to form display data into packets and provided to the display panel 4 are for implementing a function of a timing controller generally employed in a display device, and a description thereof will be omitted.

In addition, the display board 2 may include a luminance data providing unit 1 for providing luminance data corresponding to the display data, and may provide the luminance data to the backlight driving board 6 .

The resolution of the display panel 4 for expressing an image and the resolution of the backlight board 40 providing the backlight are different. Also, a gray range and a gray value for the backlight may be set differently. Therefore, the backlight board 40 requires backlight data including resolution and gray values for expressing backlight.

One frame of the backlight of the backlight board 40 includes a plurality of horizontal periods, and each horizontal period means a period in which backlight data is provided to columns of one horizontal line in one frame. The backlight data includes column data corresponding to columns of horizontal periods included in one frame.

The luminance data providing unit 1 may generate luminance data satisfying the resolution and gray value of the backlight by using the display data. For example, the luminance data providing unit 1 may provide the display data as luminance data as it is, or may provide the luminance data obtained by converting the display data to have a resolution and a gray value corresponding to the backlight.

The display board 2 is configured to generate luminance data configured in a format that can be received by the backlight driving board 6 , and provide the luminance data to the backlight driving board 6 through the transmission line 5 .

In addition, the display board 2 may provide the above-described vertical synchronization signal Vsync to the backlight driving board 6 through the transmission line 5a. The vertical synchronization signal Vsync is provided to the backlight driving board 6 to synchronize the operations of the display panel 4 and the backlight board 40 .

The backlight driving board 6 receives the luminance data and the vertical synchronization signal Vsync from the display board 2, and provides the backlight data to the backlight board 40 through a transmission line 7 having a plurality of transmission channels, and provides vertical synchronization and provide the signal Vsync to the backlight board 40 via the transmission line 7a.

The backlight board 40 is configured to receive the backlight data of the backlight driving board 6 and the vertical synchronization signal Vsync, and provide backlight to the display panel 40 by emitting light emitting diode channels in response to the backlight data. In addition, the backlight board 40 is configured to use the vertical synchronization signal Vsync to drive the LED channels in horizontal period units.

The backlight driving board 6 and the backlight board 40 of FIG. 14 may be described in more detail with reference to FIG. 15 .

The backlight driving board 6 may be configured to include a controller 60 , a conversion memory 62 , and a storage unit DCM.

The controller 60 receives the luminance data transmitted through the transmission line 5 and generates column data and raw data corresponding to the resolution of the backlight by using the luminance data, and backlight data including the column data and raw data is configured to provide to the backlight board 40 via the transmission line 7 .

The controller 60 may generate column data and raw data corresponding to a horizontal period of the backlight by using the vertical synchronization signal Vsync, and configure the backlight data to include the column data and raw data. In this case, the controller 60 may time-divide the frequency of the vertical synchronization signal Vsync to generate column data and row data for each horizontal period of the backlight.

The conversion memory 62 may include conversion data. The converted data may be used to generate column data using the luminance data of the controller 60 . The converted data corresponds to the luminance data and may have the number and value of bits suitable for the resolution and brightness scale of the backlight.

The storage unit DCM may store current deviation compensation data. Here, the current deviation compensation data includes a value for compensating for a current deviation set for each light emitting block. The current deviation compensation data may be understood as having a value for compensating for a current deviation set for each light emitting block according to the description with reference to FIGS. 11 to 13 .

The controller 60 generates column data by selecting the converted data of the conversion memory 62 corresponding to the luminance data for each light emitting diode channel in the process of generating the column data, and then stores the column data for each light emitting diode channel to compensate for current deviation Compensated column data for each LED channel is generated by selecting the current deviation compensation data of the DCM and adding the selected current deviation compensation data to the column data.

The backlight driving board 6 may transmit the backlight data generated by the controller 60 into a packet and then transmit it to the backlight board 40 through the transmission line 7 . It may be understood that column data included in the backlight data transmitted from the backlight driving board 6 is compensated for current deviation compensation. In addition, the backlight driving board 6 may further include a transmission module (not shown) that configures and transmits the backlight data into packets.

On the other hand, the backlight board 40 includes a communication module 42 that receives backlight data and a vertical synchronization signal Vsync, a column driver 10 that provides a column signal corresponding to the column data, and a row signal that provides a row signal corresponding to the row data. The row driver 20 may include a plurality of light emitting diode channels providing a backlight, and current control circuits disposed for each of a plurality of control units for dividing the plurality of light emitting diode channels.

Among them, light emitting diode channels are denoted by “CH11 to CH23” and omitted in comparison with FIG. 1 , and current control circuits are denoted by “T11 to T13” by omitting in comparison with FIG. 1 . In addition, the region in which the LED channels and current control circuits are formed is defined as the backlight region 30 , and the column driver 10 , the row driver 20 and the communication module 42 are formed in the backlight region ( 30) may be formed on the outside.

The communication module 42 receives the backlight data through the transmission line 7 and receives the vertical synchronization signal Vsync through the transmission line 7a.

The communication module 42 generates a column control signal LEN and a row control signal DMS which are toggled in units of a horizontal period of the backlight in response to the vertical synchronization signal Vsync. The communication module 42 is configured to provide the column control signal LEN to the column driver 10 and provide the row control signal DMS to the row driver 20 .

In addition, the communication module 42 is configured to distinguish column data and raw data from the received backlight data, provide the column data to the column driver 10 , and provide the row data to the row driver 20 . The communication module 42 may have a function of restoring column data and raw data from the backlight data transmitted as a packet. In addition, the communication module 42 may provide the column data and the row data to the column driver 10 and the row driver 20 in units of horizontal periods, respectively, by using the vertical synchronization signal Vsync.

In addition, the column driver 10 is configured to receive column data in units of a horizontal period and perform digital-to-analog conversion of converting column data for each column of the backlight into an analog column signal using the column control signal LEN.

In addition, the row driver 20 is configured to receive raw data in units of a horizontal period and sequentially output a row signal corresponding to the raw data for each horizontal period of the backlight using the row control signal DMS.

The column signal of the column driver 10 and the row signal of the row driver 20 may be provided to the current control circuits T11 to T13 for light emission of the light emitting diode channels CH11 to CH23.

As described above, the column driver 10 and the row driver 20 may generate the column control signal LEN and the row control signal DMS by using the row control signal DMS.

Therefore, the column control signal LEN and the row control signal DMS are output from the communication module 42 as described above and may have a frequency corresponding to the horizontal period of the backlight. The column control signal LEN and the row control signal DMS are the same in that they have a frequency corresponding to the horizontal period of the backlight, but may be distinguished by differences in enable timing and pulse duration.

With the above configuration, the column driver 10 provides column signals corresponding to column data in units of horizontal periods in synchronization with the column control signal LEN, and the row driver 20 synchronizes with the row control signal DMS for each horizontal period. The raw signals may be provided sequentially.

Meanwhile, the current control circuits T11 to T13 receive the column signal and the row signal of the corresponding control unit, sequentially sample the column signal by the row signal for each horizontal period of the backlight, and the light emitting diode according to the sampled voltage. and sequentially control the light emission of the channels. Here, the column signal corresponds to the light emitting input voltage Dout cited in the description of FIGS. 8 to 13 , and has a level for offsetting the input offset voltage Voffset by compensating the current deviation for column data of the controller 60 . can be understood

The configuration and operation of the current control circuits T11 to T13 and the light emitting diode channels CH11 to CH23 may be understood through the aforementioned FIGS. 1 to 11 .

Each of the current control circuits T11 to T13 receives the row signals and the column signal corresponding to the column data for which the current deviation is compensated.

The buffer BF provided in each of the current control circuits T11 to T13 receives the column signal, and the current for light emission of the light emitting diode channels CH11 to CH23 is to be controlled by the output of the buffer BF. can

The column signal is provided to the buffer BF to have a level for canceling the input offset voltage Voffset. Therefore, the input offset voltage Voffset of the buffer BF may be offset by the corrected level of the column signal.

As a result, the current control circuits T11 to T13 are sequentially input row signals and column signals having a level at which the current deviation is compensated, and can control sequential emission of light emitting diode channels belonging to the control unit without input deviation. .

A more detailed configuration of the column driver 10 may be described with reference to FIG. 16 .

The column driver 10 may include latches 12a, 14a, 16a ... and digital-to-analog converters 12b, 14b, 16b ... for each column of the backlight.

The latches 12a, 14a, 16a ... are configured to latch sequentially transferred column data column by column and receive the column control signal LEN.

When the column control signal LEN is provided, the latches 12a, 14a, 16a ... are synchronized with the enable time of the column control signal LEN to transfer the latched column data to the digital-to-analog converters 12b, 14b, 16b. ..) is configured to forward simultaneously.

The digital-to-analog converters 12b, 14b, 16b ... correspond to column data when column data of the latches 12a, 14a, 16a ... are simultaneously received in synchronization with the enable time of the column control signal LEN. It is configured to output the analog column signals D1, D2, D3 ... at the same time. Each of the digital-to-analog converters 12b, 14b, 16b ... may be understood as performing digital-to-analog conversion for converting column data into analog column signals.

The enable point of the column control signal LEN is repeated in units of the horizontal period of the backlight, and the digital-to-analog conversion of the column driver 10 converts column data for each column of the backlight into an analog column signal in synchronization with the column control signal LEN for the backlight. is repeated in units of a horizontal period of

In addition, a more detailed configuration of the row driver 20 may be described with reference to FIG. 17 .

The row driver 20 may be configured as a demultiplexer or decoder.

The row driver 20 may receive the row control signal DMS enabled in units of horizontal periods, and in synchronization with the row control signal DMS, row signals G1, G2, G3 .. corresponding to row data for each horizontal period of the backlight. . is configured to output sequentially.

The backlight device for a display of the present invention described with reference to FIGS. 14 to 17 transfers luminance data corresponding to the display data of the display panel 4 from the display board 2 to the backlight driving board 6 as described above. and the backlight driving board 6 is configured to provide backlight data corresponding to the luminance data to the backlight board 40 .

The column data of the backlight data may be generated by selecting the converted data of the conversion memory 62 corresponding to the luminance data for each light emitting diode channel by the controller 60 of the backlight driving board 6 , and then for each light emitting diode channel It may be converted to compensate for the current deviation by using the current deviation compensation data of the storage unit DCM.

In addition, in the backlight board 40 , the column signal of the column driver 10 and the row signals of the row driver 20 are provided to current control circuits for each control unit, and the current control circuits are pure with the input offset voltage Voffset cancelled. Light emission of the LED channels may be controlled in response to the block emission voltage DCH.

As a result. Current deviation for each LED channel due to the input offset voltage Voffset may be improved.

Meanwhile, the present invention may be implemented such that the backlight driving board 6 includes a part or the entirety of the compensation circuit 700 of FIG. 10 .

At this time, the compensation circuit 700 converts the output of the resistor (R) for sensing the current supplied to the backlight board, the buffer (SB) for outputting the voltage applied to the resistor (R), and the output of the buffer (SB) into a digital value. It may be configured to include an ADC 712 , a switch (SWC) and a controller 720 . Here, the ADC 712 may be understood as a component constituting an input terminal of the buffer SB or an output terminal of the controller 720 .

The configuration and operation of the resistor R, the buffer SB, the ADC 712 , the switch SWC, and the controller 720 can be understood with reference to FIG. 12 , and thus a redundant description thereof will be omitted.

In the above configuration, the controller 720 refers to the total leakage voltage measured when all of the light emitting diode channels are extinguished and the block light emitting voltage for each light emitting diode channel measured by sequentially emitting all the light emitting blocks one by one. It may be configured to generate star current deviation compensation data and update the current deviation compensation data to the storage unit DCM of the backlight driving board 6 .

The controller 720 may be understood to correspond to the controller 60 of the backlight driving board 6 , and generates current deviation compensation data for each light emitting diode channel when the display is powered on, and generates current deviation compensation data It may be configured to update the storage unit (DCM).

The generation of the current deviation compensation data by the controller 720 can be understood with reference to FIGS. 11 to 13 , and thus a redundant description thereof will be omitted.

Meanwhile, the present invention may be embodied in that the backlight board 40 includes a storage unit DCM as shown in FIG. 18 .

When the backlight board 40 includes a storage unit DCM for storing current deviation compensation data, compensation of column data for compensating the current deviation may be performed on the backlight driving board 6 or the backlight board 40 . have.

First, when the backlight driving board 6 compensates for column data, the backlight driving board 6 receives the current deviation compensation data of the storage unit DCM, and the backlight including the compensated column data as the current deviation compensation data. configured to output data.

More specifically, the controller 60 of the backlight driving board 6 receives the luminance data of the conversion memory 62 and the current deviation compensation data of the storage unit DCM of the backlight board 40, and uses the luminance data to The column data and raw data corresponding to the resolution of the backlight are generated, the column data is compensated with the current deviation compensation data of the storage unit (DCM), and the backlight data including the raw data and the compensated column data is output to the backlight board 40 . can be provided to

At this time, so that the communication module 42 of the backlight board 40 provides current deviation compensation data from the storage unit DCM to the backlight driving board 6 in response to the request of the controller 60 of the backlight driving board 6 . is composed

The operation of the backlight board 40 by compensating for the current deviation of the light emitting diode channels using the compensated column data can be understood with reference to the embodiments of FIGS. 14 to 17 , and thus a redundant description thereof will be omitted.

Meanwhile, when the backlight board 40 compensates for column data, the controller 60 of the backlight driving board 6 uses the luminance data of the conversion memory 62 to provide column data and raw data corresponding to the resolution of the backlight. and is configured to provide backlight data including raw data and column data to the backlight board 40 .

Correspondingly, the backlight board 40 is configured to compensate column data using the current deviation compensation data of the storage unit DCM and provide a column signal corresponding to the compensated column data.

To this end, the backlight board 40 is configured to include the communication module 42 and a storage unit DCM for storing the current deviation compensation data.

Then, the communication module 42 receives the column data and the raw data of the backlight data, receives the current deviation compensation data of the storage unit (DCM), generates the column data compensated by the current deviation compensation data, and the raw data and and output compensated column data.

The operation of the backlight board 40 by compensating for the current deviation of the light emitting diode channels using the compensated column data can be understood with reference to the embodiments of FIGS. 14 to 17 , and thus a redundant description thereof will be omitted.

Also, the present invention may be implemented such that the backlight board 40 includes a part or the entirety of the compensation circuit 700 of FIG. 10 .

At this time, the compensation circuit 700 converts the output of the resistor (R) for sensing the current supplied to the backlight board, the buffer (SB) for outputting the voltage applied to the resistor (R), and the output of the buffer (SB) into a digital value. It may be configured to include an ADC 712 , a switch (SWC) and a controller 720 . Here, the ADC 712 may be understood as a component constituting an input terminal of the buffer SB or an output terminal of the controller 720 .

The configuration and operation of the resistor R, the buffer SB, the ADC 712 , the switch SWC, and the controller 720 can be understood with reference to FIG. 12 , and thus a redundant description thereof will be omitted.

In the above configuration, the controller 720 uses the total leakage voltage measured when all of the light emitting diode channels are extinguished and the block light emitting voltage for each light emitting diode channel measured by sequentially emitting all the light emitting blocks one by one. It may be configured to generate star current deviation compensation data and update the current deviation compensation data to the storage unit DCM.

In addition, the controller 720 may be understood to be included in the communication module 42 or configured outside the communication module 42, and generates current deviation compensation data for each light emitting diode channel at the power-on time of the display, It may be configured to update the deviation compensation data in the storage unit DCM.

The generation of the current deviation compensation data by the controller 720 can be understood with reference to FIGS. 11 to 13 , and thus a redundant description thereof will be omitted.

As described above, in the present invention, the sampling voltage of the capacitor sampling the column signal is maintained during the frame period, and the driving current of the light emitting diode channel can be controlled to maintain light emission in units of frames by the sampling voltage maintained during the frame period. As a result, it is possible to reduce or eliminate flicker caused by the backlight device of the display.

In addition, according to the present invention, since the current control integrated circuit is configured for each control unit including a plurality of light emitting diode channels, it is possible to ensure the convenience of designing and manufacturing for controlling the driving currents of the light emitting diode channels on the backlight board.

In addition, the present invention can improve gray uniformity and dark uniformity evaluated in the low current band by resolving the current deviation of the light emitting diode channel due to the input offset voltage, which may act relatively large in the low current band.

Also, according to the present invention, the light emitting uniformity can be improved by storing the current deviation compensation data in the storage unit and compensating the column data with the current deviation compensation data to compensate the current deviation due to the input offset voltage of the LED channels of the backlight device. .

Claims (21)

a backlight driving board that provides column data for a backlight of a display; and
A storage unit for storing current deviation compensation data, a backlight board providing the backlight and having a plurality of light emitting blocks divided into a plurality of control units and current control circuits corresponding to the plurality of control units;
The current deviation compensation data includes a value for compensating for a current deviation set for each light emitting block,
The backlight driving board receives the current deviation compensation data of the storage unit and outputs the column data compensated by the current deviation compensation data;
Each of the current control circuits belongs to the control unit and sequentially receives light emitting input voltages corresponding to the column data for which the current deviation is compensated, and sequentially emits light of the light emitting blocks belonging to the control unit as the light emitting input voltages. A backlight device for a display, characterized in that for controlling the. According to claim 1,
each of the current control circuits has a buffer for receiving the light emitting input voltage, and controls a current for light emission of the light emitting block by an output of the buffer;
The current deviation compensation data is set to have a value for compensating for a deviation of an input offset voltage by the current control circuit including the buffer. According to claim 1,
The current deviation compensation data corresponds to a value obtained by subtracting the equivalent input voltage corresponding to one block light emission current from the light emission input voltage of the block;
The equivalent input voltage is a value calculated using a pure block light-emitting voltage,
The pure block light emission voltage corresponds to a value obtained by subtracting the partial leakage voltage from the block light emission voltage,
The block emission voltage is a value generated by measuring the block emission current when one designated light emitting block emits light by the light emission input voltage,
The partial leakage voltage is a value calculated using a total leakage current when all of the light emitting blocks are extinguished. According to claim 1,
The backlight driving board further includes a compensation circuit,
The compensation circuit is
a resistor for sensing a current supplied to the backlight board;
a buffer for outputting a voltage applied to the resistor; and
The current deviation compensation data for each light emitting block is obtained by using the equivalent voltage corresponding to the total leakage current measured when all the light emitting blocks are extinguished and the block light emission voltage for each light emitting block measured by sequentially emitting all the light emitting blocks one by one a controller to generate; and
The controller is configured to update the current deviation compensation data to the storage unit. 5. The method of claim 4,
The controller generates the current deviation compensation data for each light emitting block when the display is powered on, and updates the current deviation compensation data to the storage unit. 5. The method of claim 4, wherein the controller,
A partial leakage current corresponding to the partial leakage current for the remaining light emitting blocks except for one light emitting block is generated using the total leakage current when all of the light emitting blocks are extinguished,
Measure the block emission current when one designated light emitting block emits light by the light emission input voltage,
generating a pure block light-emitting voltage by subtracting a partial leakage current from the block light-emitting current;
An equivalent input voltage of the light-emitting block is calculated using the pure block light-emitting voltage,
The current deviation compensation data is generated by the current control circuit from the equivalent input voltage generating the current deviation compensation data corresponding to a value obtained by subtracting the equivalent input voltage corresponding to one block light emission current from the light emission input voltage of the block A backlight device for a display that generates the current deviation compensation data corresponding to a value obtained by subtracting the equivalent input voltage corresponding to one block light emission current by . According to claim 1,
The backlight driving board receives luminance data for the backlight, generates column data and raw data corresponding to the resolution of the backlight using the luminance data, receives the current deviation compensation data of the storage unit, and A backlight device for a display that compensates the column data using current deviation compensation data and provides the backlight data including the raw data and the compensated column data to the backlight board. 8. The method of claim 7,
The backlight driving board,
a conversion memory containing conversion data; and
and a controller receiving the luminance data and the current deviation compensation data of the storage unit and outputting the column data,
The controller is
selecting the converted data of the conversion memory corresponding to the luminance data;
generating the column data and the raw data corresponding to the resolution of the backlight as the conversion data;
Compensating the column data with the current deviation compensation data,
A backlight device for a display outputting the raw data and the compensated column data. The method of claim 7, wherein the backlight board,
the storage unit for storing the current deviation compensation data;
the plurality of light emitting blocks;
the current control circuits;
a column driver receiving the column data of the backlight data and providing the light emitting input voltages corresponding to the column data as column signals; and
a row driver receiving the raw data of the backlight data and providing raw signals corresponding to the raw data;
Each of the current control circuits sequentially receives the light emitting input voltages and the raw signals belonging to the control unit, samples the light emitting input voltage by the raw signal for each horizontal period of the backlight, and receives the sampled voltage. and controlling light emission of the light emitting blocks belonging to the control unit by a backlight device. 10. The method of claim 9,
The backlight board further includes a communication module for receiving the backlight data and a vertical synchronization signal for the display, and providing the current deviation compensation data from the storage unit to the backlight driving board,
The communication module provides the current deviation compensation data of the storage unit to the backlight driving board in response to a request from the backlight driving board, outputs the column data and the row data included in the backlight data, and the vertical synchronization generating and outputting a column control signal and a row control signal having a frequency corresponding to the horizontal period of the backlight using the signal;
the column driver provides the light emitting input voltage corresponding to the column data in units of the horizontal period in synchronization with the column control signal;
The row driver is configured to provide the row signal corresponding to the row data in units of the horizontal period in synchronization with the row control signal. a backlight driving board that provides column data for a backlight of a display; and
A storage unit for storing current deviation compensation data, a backlight board providing the backlight and having a plurality of light emitting blocks divided into a plurality of control units and current control circuits corresponding to the plurality of control units;
The backlight board receives the column data, compensates the column data with the current deviation compensation data of the storage unit, and provides a light emitting input voltage corresponding to the compensated column data,
Each of the current control circuits sequentially receives the light emitting input voltages belonging to the control unit, and controls the sequential light emission of the light emitting blocks belonging to the control unit with the light emission input voltages. Device. 12. The method of claim 11,
each of the current control circuits has a buffer for receiving the light emitting input voltage, and controls a current for light emission of the light emitting block by an output of the buffer;
The current deviation compensation data is set to have a value for compensating for a deviation of an input offset voltage by the current control circuit including the buffer. 12. The method of claim 11,
The current deviation compensation data corresponds to a value obtained by subtracting the equivalent input voltage corresponding to one block light emission current from the light emission input voltage of the block;
The equivalent input voltage is a value calculated using a pure block light-emitting voltage,
The pure block light emission voltage corresponds to a value obtained by subtracting the partial leakage voltage from the block light emission voltage,
The block emission voltage is a value generated by measuring the block emission current when one designated light emitting block emits light by the light emission input voltage,
The partial leakage voltage is a value calculated using a total leakage current when all of the light emitting blocks are extinguished. 12. The method of claim 11,
The backlight driving board further includes a compensation circuit,
The compensation circuit is
a resistor for sensing a current supplied to the backlight board;
a buffer for outputting a voltage applied to the resistor; and
A controller configured to generate the current deviation compensation data for each light emitting block by using the total leakage current measured when all the light emitting blocks are all extinguished and the block light emitting current for each light emitting block measured by sequentially emitting all the light emitting blocks one by one; do,
The controller is configured to update the current deviation compensation data to the storage unit. 15. The method of claim 14,
The controller generates the current deviation compensation data for each light emitting block when the display is powered on, and updates the current deviation compensation data to the storage unit. 15. The method of claim 14,
The controller is
A partial leakage current corresponding to the partial leakage current for the remaining light emitting blocks except for one light emitting block is generated using the total leakage current when all of the light emitting blocks are extinguished,
Measure the block emission current when one designated light emitting block emits light by the light emission input voltage,
generating a pure block light-emitting voltage by subtracting a partial leakage current from the block light-emitting current;
An equivalent input voltage of the light-emitting block is calculated using the pure block light-emitting voltage,
The current deviation compensation data generates the current deviation compensation data corresponding to a value obtained by subtracting the equivalent input voltage corresponding to one block light emission current from the light emission input voltage of the block. 12. The method of claim 11,
The backlight driving board receives luminance data for the backlight, generates column data and raw data corresponding to the resolution of the backlight by using the luminance data, and the backlight data including the raw data and the column data A backlight device for a display to provide the backlight board. 18. The method of claim 17,
The backlight driving board,
a conversion memory containing conversion data; and
and a controller for receiving the luminance data and outputting the column data,
The controller is
selecting the converted data of the conversion memory corresponding to the luminance data;
generating the column data and the raw data corresponding to the resolution of the backlight as the conversion data;
A backlight device for a display outputting the raw data and the column data. 19. The method of claim 18,
The controller receives a vertical synchronization signal for the display, and generates the column data and the row data by using the vertical synchronization signal. The method of claim 17, wherein the backlight board,
a communication module for receiving the backlight data and a vertical synchronization signal for the display; and
Including; the storage unit for storing the current deviation compensation data,
The communication module receives the column data and the raw data of the backlight data, receives the current deviation compensation data of the storage unit, generates the column data compensated by the current deviation compensation data, the raw data and A backlight device for a display that outputs the compensated column data and generates and outputs a column control signal and a row control signal having a frequency corresponding to the horizontal period of the backlight by using the vertical synchronization signal. The method of claim 17, wherein the backlight board,
the plurality of light emitting blocks;
the current control circuits;
a column driver receiving the column data and the column control signal and providing the light emitting input voltages corresponding to the column data as column signals in synchronization with the column control signal in units of the horizontal period; and
a row driver receiving the row data and the row control signal and providing row signals corresponding to the row data in units of the horizontal period in synchronization with the row control signal;
Each of the current control circuits sequentially receives the light emitting input voltages and the raw signals belonging to the control unit, samples the light emitting input voltage by the raw signal for each horizontal period of the backlight, and receives the sampled voltage. and controlling light emission of the light emitting blocks belonging to the control unit by a backlight device.

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