KR20060093972A - Liquid crystal display device of having luminance corrector - Google Patents

Abstract

A liquid crystal display device having a luminance correction unit is disclosed. Optical sensor for detecting the light passing through the hole provided in the reflector plate to supply an electrical signal, a feedback controller for receiving the electrical signal to supply a luminance correction control signal, the optical sensor and the feedback controller An integrated luminance compensator having a printed circuit board for electrically connecting the optical sensor and the feed back controller and supplying the luminance correction control signal to a backlight controller while integrally mounted thereon. To improve the unevenness of brightness.

LCD, luminance correction unit, luminance correction control signal, ball grid

Description

Liquid crystal display device having a luminance correction unit {Liquid Crystal Display Device of having luminance corrector}

1 is a block diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

2A illustrates a liquid crystal display module according to an exemplary embodiment of the present invention.

2B is a view showing another liquid crystal display module according to an embodiment of the present invention.

2C is a view showing another liquid crystal display module according to an embodiment of the present invention.

2D is a view showing another liquid crystal display module according to an embodiment of the present invention.

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a luminance correction unit in which an optical sensor and a feedback controller are integrated to achieve uniform light intensity.

Recently, with the light weight and thinness of personal computers and TVs, display devices are also required to be lighter and thinner, and according to such demands, flat panel displays such as liquid crystal displays have been developed instead of cathode ray tubes (CRTs). have.

A liquid crystal display device applies an electric field to a liquid crystal material having anisotropic dielectric constant injected between two substrates, and adjusts the intensity of the electric field to adjust the amount of light transmitted from an external light source (backlight) to the substrate. It is a display device that obtains a desired image signal.

Such a liquid crystal display is a typical flat panel display that is easy to carry. Among them, a TFT-LCD using a thin film transistor (TFT) as a switching element is mainly used.

The liquid crystal display includes a liquid crystal display panel for displaying an image, a gate driver for supplying a scan signal to the liquid crystal display panel, a source driver for supplying a data signal to a pixel selected for the scan signal, and a liquid crystal display panel for the liquid crystal display panel. And a backlight controller for irradiating light, a backlight controller for controlling the backlight unit, and a timing controller for supplying control signals for controlling the liquid crystal display panel, the gate driver, the source driver, and the backlight controller.

However, the image displayed on the liquid crystal display panel is greatly affected by the surrounding environment, especially temperature, and thus it is difficult to maintain uniform luminance. Accordingly, a liquid crystal display device having various luminance correction units for maintaining uniform luminance has been disclosed. However, the present invention provides a liquid crystal display device having a brightness correction unit for maintaining a uniform brightness by integrating an optical sensor and a feedback controller.

SUMMARY OF THE INVENTION An object of the present invention for overcoming the above problem is to provide a liquid crystal display device having a luminance correction unit in which an optical sensor and a feedback controller are integrated to achieve uniform luminance.

According to an aspect of the present invention, a liquid crystal display panel having a plurality of pixels, a gate driver for supplying a scan signal to the liquid crystal display panel, and a data signal to a pixel selected by the scan signal are provided. And a source driver, a lamp, a light guide plate, and a reflecting plate for supplying the light source, a backlight unit for irradiating light to the liquid crystal display panel, and detecting light from the backlight unit to generate an electric signal, and to control luminance correction according to the electric signal. A brightness controller for supplying a signal, a backlight controller for supplying a driving voltage corrected according to the brightness correction control signal, and a timing controller for supplying control signals for controlling the gate driver, the source driver, and the backlight controller; It is to provide a liquid crystal display device comprising.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

Example

1 is a block diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display includes a liquid crystal panel 100, a gate driver 110, a source driver 120, a timing controller 130, a backlight controller 140, a backlight unit 150, and a luminance corrector. It consists of 160.

The liquid crystal panel 100 has pixels P ₁₁ -P _NM defined in an area where the data lines D ₁ -D _m intersect the scan lines G ₁ -G _n . The pixels P ₁₁ -P _NM have a liquid crystal C _LC for displaying an image.

The gate driver 110 supplies a scan signal to the pixels P ₁₁ -P _NM through the scan lines G ₁ -G _n . The thin film transistor MS of the pixel to which the scan signal is applied is selectively turned on, and the data signal can be written.

The source driver 120 supplies a data signal to the pixels P ₁₁ -P _NM through the data lines D ₁ -D _m . The liquid crystal C _LC of the pixel has a predetermined alignment state according to a data signal applied between the pixel electrode and the common electrode, and a gray level of an image is expressed according to the alignment state.

The timing controller 130 generates respective control signals S _g , S _d , and S _r for controlling the gate driver 110, the source driver 120, and the backlight controller 140.

The backlight controller 140 receives the control signal S _r from the timing controller 130 and supplies a control signal for controlling the backlight unit 150 to the backlight unit 150, and also provides the luminance compensation. The luminance correction control signal is supplied from the government unit 160, and a control signal for applying an optimized driving voltage to the backlight unit 150 is supplied to the backlight unit 150.

The backlight unit 150 includes a lamp, a reflector, a light guide plate, a diffusion sheet, a prism sheet, and a mold frame.

The lamp serves as a light source for irradiating light to the liquid crystal display panel, and a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED) are used. Particularly in the field sequential driving liquid crystal display device, R, G, and B light emitting diodes are used as the lamps.

The light guide plate acts as a kind of optical lens for injecting light from the lamp into the inside to emit a uniform surface light source to the upper surface.

The diffusion sheet uniformly diffuses the light from the light guide plate on the screen to widen the viewing angle and conceal the pattern formed on the light guide plate.

The prism sheet increases the front luminance by refracting and condensing the light emitted from the diffusion. The prism sheet serves to enhance the brightness of the light by focusing the light again using two sets of almost horizontal and vertical sheets.

The reflector is located at the rear of the light guide plate to reflect the light emitted from the lamp to the front to prevent the loss of light generated at the bottom of the light guide plate to increase the brightness. Light irradiated from the lamp is supplied to the luminance corrector through the reflector.

The luminance corrector 160 detects light emitted from the lamp to generate an electrical signal, and supplies a luminance correction control signal to the backlight controller 140 according to the electrical signal.

2A illustrates a liquid crystal display module according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, the liquid crystal display includes a liquid crystal display panel 200, a backlight unit 250, and a luminance corrector 260.

The liquid crystal display panel 200 displays an image with a plurality of pixels defined in an intersection area of a plurality of scan lines and a plurality of data lines.

The backlight unit 250 irradiating light to the liquid crystal display panel 200 may include a lamp housing 251, a lamp 252, a reflecting plate 253, a light guide plate 254, a diffusion sheet 255, and a prism sheet 256. ). The reflector 253 includes at least one hole 257, and the light irradiated from the lamp 252 through the at least one hole 257 is transmitted to the luminance corrector 260. .

The luminance corrector 260 is located behind the backlight unit 250 and receives the light passing through the at least one hole 257 provided in the reflective plate 253 to convert the light into an electrical signal. The luminance correction control signal is supplied to the backlight controller according to the electrical signal.

The luminance corrector 260 includes an optical sensor 262, a feedback controller 263, and a printed circuit board 261.

The optical sensor 262 is located behind the backlight unit 250, detects the light passing through the at least one hole 257 provided in the reflector 253, and converts the light into the electrical signal. The signal is supplied to the feedback controller 263. The optical sensor 262 may be composed of a photo diode or a photo transistor.

The feedback controller 263 receives the electrical signal to compare and determine the electrical signal with a reference signal to supply the luminance correction control signal to the backlight controller. The reference signal is stored in the feedback controller 263 in the form of a lookup table.

In this case, the optical sensor 262 and the feed back controller 263 are integrally mounted on the printed circuit board 261, and the optical sensor 262 and the feed back controller 263 are wire bonded. bonding). The luminance correction control signal is supplied to the backlight controller through the printed circuit board 261.

2B is a view showing another liquid crystal display module according to an embodiment of the present invention.

Referring to FIG. 2B, the liquid crystal display includes a liquid crystal display panel 300, a backlight 350, and a luminance corrector 360.

The liquid crystal display panel 300 displays an image with a plurality of pixels defined in an intersection area of a plurality of scan lines and a plurality of data lines.

The backlight unit 350 irradiating light to the liquid crystal display panel 300 may include a lamp housing 351, a lamp 352, a reflector 353, a light guide plate 354, a diffusion sheet 355, and a prism sheet 356. ). The reflector 353 includes at least one hole 357, and the light emitted from the lamp 352 is transmitted to the luminance corrector 360 through the at least one hole 357. do.

The luminance corrector 360 is located behind the backlight 350 and receives the light passing through the at least one hole 357 to convert the light into an electrical signal, and controls the luminance correction according to the electrical signal. Supply the signal to the backlight controller.

The luminance corrector 360 includes an optical sensor 361, a feedback controller 362, a first printed circuit board 363, a ball grid 364, and a second printed circuit board 365. do.

The optical sensor 361 is positioned behind the backlight unit 350, and detects the light passing through the at least one hole 357 provided in the reflector 353 to convert the light into the electrical signal, and converts the electrical signal into the electrical signal. A signal is supplied to the feedback controller 362. The optical sensor 361 may be configured as a photo diode or a photo transistor.

The feedback controller 362 receives the electrical signal, compares and determines the electrical signal with a reference signal, and supplies the luminance correction control signal to the backlight controller. The reference signal is stored in the feedback controller 362 in the form of a lookup table.

In this case, the optical sensor 361 and the feed back controller 362 are integrally mounted on the first printed circuit board 363, and the optical sensor 361 and the feed back controller 362 are wire bonded. (wire bonding).

The ball grid 364 maintains a constant distance between the reflective plate 353 and the first printed circuit board 363, and transmits the luminance correction control signal to the second printed circuit board ( 365). The ball grid 364 is mounted on a printed circuit board by surface mounted technology as a surface mounted device.

The second printed circuit board 365 is positioned between the ball grid 364 and the reflecting plate 353, and the backlight is connected to the second printed circuit board 365 through wirings mounted on the second printed circuit board 365. The backlight controller receives the brightness correction control signal and supplies a control signal for applying an optimized driving voltage to the backlight unit 350.

2C is a view showing another liquid crystal display module according to an embodiment of the present invention.

Referring to FIG. 2C, the liquid crystal display includes a liquid crystal display panel 400, a backlight 450, and a luminance corrector 460.

The liquid crystal display panel 400 displays an image with a plurality of pixels defined in an intersection area of a plurality of scan lines and a plurality of data lines.

The backlight unit 450 irradiating light to the liquid crystal display panel 400 includes a lamp housing 451, a lamp 452, a reflecting plate 453, a light guide plate 454, a diffusion sheet 455, and a prism sheet 456. ). The light irradiated from the lamp 452 is transmitted to the luminance corrector 460 through the reflector 454. In this case, the reflective plate 453 does not have a hole.

The luminance corrector 460 is located behind the backlight unit 450, receives the light passing through the reflector 453, converts the light into an electrical signal, and converts the luminance correction control signal according to the electrical signal. Supply to the backlight controller.

The luminance corrector 460 includes an optical sensor 461, a feedback controller 462, and a printed circuit board 463.

The optical sensor 461 is positioned behind the backlight 450, detects the light passing through the reflector 453, converts the light into the electrical signal, and supplies the electrical signal to the feed back controller 462. do. The optical sensor 461 may be configured as a photo diode or a photo transistor.

The feedback controller 462 receives the electrical signal, compares the electrical signal with a reference signal, determines the luminance signal, and supplies the luminance correction control signal to the backlight controller. The reference signal is stored in the feedback controller 462 in the form of a lookup table.

In this case, the optical sensor 461 and the feedback controller 462 are integrally mounted on the printed circuit board 463, and the optical sensor 461 and the feedback controller 462 are wire bonded. bonding). The luminance correction control signal is supplied to the backlight controller through the printed circuit board 463.

2D is a view showing another liquid crystal display module according to an embodiment of the present invention.

Referring to FIG. 2D, the liquid crystal display includes a liquid crystal display panel 500, a backlight 550, and a luminance corrector 560.

The liquid crystal display panel 500 displays an image with a plurality of pixels defined in an intersection region of a plurality of scan lines and a plurality of data lines.

The backlight unit 550 irradiating light to the liquid crystal display panel 500 may include a lamp housing 551, a lamp 552, a reflecting plate 553, a light guide plate 554, a diffusion sheet 555, and a prism sheet 556. ). The light irradiated from the lamp 552 is transmitted to the luminance corrector 560 through the reflector 553. In this case, the reflective plate 553 does not have a hole.

The luminance corrector 560 is located behind the backlight unit, receives the light passing through the reflector, converts the light into an electrical signal, and supplies a luminance correction control signal to the backlight controller according to the electrical signal.

The luminance corrector 560 includes an optical sensor 561, a feedback controller 562, a first printed circuit board 563, a ball grid 564, and a second printed circuit board 565. do.

The optical sensor 561 is located behind the backlight, detects the light passing through the reflector 553, converts the light into the electrical signal, and supplies the electrical signal to the feedback controller 562. The optical sensor 561 may be configured as a photo diode or a photo transistor.

The feedback controller 562 receives the electrical signal, compares the electrical signal with a reference signal, determines the luminance signal, and supplies the luminance correction control signal to the backlight controller. The reference signal is stored in the feedback controller 562 in the form of a lookup table.

In this case, the optical sensor 561 and the feed back controller 562 are integrally mounted on the first printed circuit board 563, and the optical sensor 561 and the feed back controller 562 are wire bonded. (wire bonding).

The ball grid 564 maintains a constant distance between the reflective plate 553 and the first printed circuit board 563, and transmits the luminance correction control signal to the second printed circuit board 565. To pass). The ball grid 564 is mounted on a printed circuit board by surface mounted technology as a surface mounted device.

The second printed circuit board 564 is positioned between the ball grid 564 and the reflecting plate 553, and the backlight is connected to the backlight via wirings mounted on the second printed circuit board 565. The backlight controller receives the brightness correction control signal and supplies a control signal for applying an optimized driving voltage to the backlight unit 550.

The present invention is located behind the backlight unit, the optical sensor for sensing the light passing through at least one hole provided in the reflector to supply an electrical signal, the feed for supplying the luminance correction control signal received the electrical signal Equipped with a printed circuit board and a ball grid for electrically connecting the optical sensor and the feed back controller while mounting a back controller, the optical sensor and the feed back controller, and supplying the brightness correction control signal to a backlight controller. Through the luminance correction unit, the uniformity of the luminance is achieved with a light and simple feed back system structure having no connection cable.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (14)

A liquid crystal display panel having a plurality of pixels and for displaying an image; A gate driver for supplying a scan signal to the liquid crystal display panel; A source driver for supplying a data signal to the pixel selected by the scan signal; A backlight unit including a lamp, a light guide plate, and a reflection plate, and configured to irradiate light to the liquid crystal display panel; A luminance correction unit for generating an electrical signal by sensing light from the backlight unit and supplying a luminance correction control signal according to the electrical signal; A backlight controller for supplying a driving voltage corrected according to the brightness correction control signal; And And a timing controller for supplying control signals for controlling the gate driver, the source driver, and the backlight controller. The method of claim 1, wherein the reflector provided in the backlight unit, A liquid crystal display device comprising at least one hole. The method of claim 2, wherein the brightness correction unit, An optical sensor positioned behind the backlight unit and configured to detect light passing through the hole provided in the reflector to supply the electrical signal; A feedback controller for receiving the electrical signal and supplying the luminance correction control signal; And And a printed circuit board configured to electrically connect the optical sensor and the feedback controller while mounting the optical sensor and the feedback controller, and to supply the luminance correction control signal to the backlight controller. The method of claim 3, wherein the optical sensor, And a photodiode or phototransistor. The method of claim 2, wherein the brightness correction unit, An optical sensor positioned behind the backlight unit and configured to detect light passing through the hole provided in the reflector to supply the electrical signal; A feedback controller for receiving the electrical signal and supplying the luminance correction control signal; And And a first printed circuit board to electrically mount the optical sensor and the feedback controller while mounting the optical sensor and the feedback controller, and to supply the luminance correction control signal to the backlight controller. The method of claim 5, wherein the brightness correction unit, A ball grid for maintaining a constant distance between the first printed circuit board and the reflector and supplying the brightness correction control signal to the backlight controller; And And a second printed circuit board positioned between the ball grid and the reflector and configured to supply the brightness correction control signal to the backlight controller. The liquid crystal display device according to claim 6, wherein the ball grid is mounted on the first printed circuit board by a Surface Mounted Technology (SMT) technique. The method of claim 5, wherein the optical sensor, And a photodiode or phototransistor. The method of claim 1, wherein the brightness correction unit, An optical sensor positioned behind the backlight unit and configured to detect light passing through the reflector to supply the electrical signal; A feedback controller for receiving the electrical signal and supplying the luminance correction control signal; And And a printed circuit board configured to electrically connect the optical sensor and the feedback controller while mounting the optical sensor and the feedback controller, and to supply the luminance correction control signal to the backlight controller. The method of claim 9, wherein the optical sensor, And a photodiode or phototransistor. The method of claim 1, wherein the brightness correction unit, An optical sensor positioned behind the backlight unit and configured to detect light passing through the reflector to supply the electrical signal; A feedback controller for receiving the electrical signal and supplying the luminance correction control signal; And And a first printed circuit board to electrically mount the optical sensor and the feedback controller while mounting the optical sensor and the feedback controller, and to supply the luminance correction control signal to the backlight controller. The method of claim 11, wherein the brightness correction unit, A ball grid for maintaining a constant distance between the first printed circuit board and the reflector and supplying the brightness correction control signal to the backlight controller; And And a second printed circuit board positioned between the ball grid and the reflector and configured to supply the brightness correction control signal to the backlight controller. The liquid crystal display device according to claim 12, wherein the ball grid is mounted on the first printed circuit board by a Surface Mounted Technology (SMT) technique. The method of claim 11, wherein the optical sensor, And a photodiode or phototransistor.

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