KR20070042634A - Liquid crystal display module - Google Patents

Abstract

The present invention is to block the light leakage of the backlight unit, the liquid crystal panel for displaying an image; A backlight unit including a light source unit for generating light and supplying light generated by the light source unit to the liquid crystal panel; Disclosed is a liquid crystal display module having a blocking film attached to a rear surface of the liquid crystal panel facing the light source unit to block light from the light source unit.

LED, light leak, blocking film

Description

Liquid Crystal Display Module {LIQUID CRYSTAL DISPLAY MODULE}

1 is a view illustrating a light leakage phenomenon of a conventional liquid crystal display module.

2 is an exploded perspective view of a liquid crystal display module according to an exemplary embodiment of the present invention.

3 is a cross-sectional view of the liquid crystal display module shown in FIG. 2.

<Description of Main Parts of Drawing>

10: image display unit 12, 20: liquid crystal panel

14, 30: backlight unit 16, 26: drive IC

18, 44: LED 19: light leakage portion

22: top plate 22: bottom plate

28: main FPC

32: mold frame 34: reflective sheet

36: light guide plate 38: optical sheet

40: light source unit 42: substrate

46: light source FPC 50, 52: blocking film

60, 62: polarizing sheet

The present invention relates to a liquid crystal display module, and more particularly, to a liquid crystal display module capable of blocking light leakage of a backlight unit.

The liquid crystal display displays an image by driving liquid crystal molecules according to an electric field to adjust light transmittance. To this end, the liquid crystal display includes a liquid crystal panel for displaying an image, a driving circuit for driving the liquid crystal panel, and a back light unit for irradiating light to the liquid crystal panel.

As a light source of the backlight unit, a cold cathode fluorescent lamp (CCFL), which is a cylindrical light emitting lamp, has been generally used, but recently, a light emitting diode (LED) is focused on a small liquid crystal panel used in a mobile phone. ) Is mainly used. However, in the case of a small liquid crystal panel, the distance between the LED and the image display unit is too short, so that light leakage occurs on one side of the image display unit adjacent to the LED.

1 is a view illustrating a light leakage phenomenon in a conventional small liquid crystal display module using LED as a light source of the backlight unit.

The liquid crystal display module shown in FIG. 1 includes a liquid crystal panel 12 having an image display unit 10 and a backlight unit 14 employing an LED 18 as a light source.

The liquid crystal panel 12 is formed by the upper and lower plates bonded together with the liquid crystal layer interposed therebetween and driven by the driving IC 16 mounted on the non-display portion of the lower plate to display an image through the image display unit 10. In this case, the driving IC 16 receives a driving signal from the outside through a flexible printed circuit (FPC) film (not shown) attached to the pad region of the lower plate.

The backlight unit 14 disposed below the liquid crystal panel 12 includes an LED 18 mounted on an LED circuit board and a light guide plate and a light guide plate for guiding light incident from the LED 18 toward the liquid crystal panel 12. Reflective sheet is installed on the lower surface and reflects the light leaking to the lower side, optical sheet provided on the upper surface of the light guide plate to collect and diffuse the light incident from the light guide plate to the liquid crystal panel 12. The backlight unit 14 is mounted on the mold frame and fixed.

However, in the case of the small liquid crystal panel 12, the distance between the LED 18 and the image display unit 10 is short, so that the margin that can sufficiently block the light leaking upward from the LED 18 is insufficient. Light leakage phenomenon 19 is generated at one side of the image display unit 10, thereby degrading the image quality of the liquid crystal display module.

Accordingly, an object of the present invention is to provide a liquid crystal display module that can block light leakage of the backlight unit.

In order to achieve the above object, the liquid crystal display module according to the present invention includes a liquid crystal panel for displaying an image; A backlight unit including a light source unit for generating light and supplying light generated by the light source unit to the liquid crystal panel; And a first blocking film attached to a rear surface of the liquid crystal panel facing the light source unit to block light from the light source unit.

In addition, the liquid crystal display module of the present invention further includes a second blocking film attached to an upper surface of the light source unit.

The first blocking film has a thickness thinner than that of the polarizing sheet attached to the rear surface of the liquid crystal panel.

The first blocking film has a wider width than the second blocking film.

The light source unit includes a light emitting diode for generating the light; A circuit board on which the light emitting diode is mounted is provided.

The second blocking film is attached to the circuit board.

The first blocking film has a larger area than the light source unit.

The first blocking film is widely attached to the rear surface of the non-display unit facing the light source unit of the liquid crystal panel so as to be adjacent to the polarizing sheet.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 and 3.

2 is an exploded perspective view illustrating a liquid crystal display module according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating a portion of the liquid crystal display module illustrated in FIG. 2.

The liquid crystal display module illustrated in FIGS. 2 and 3 includes a liquid crystal panel 20 displaying an image, a backlight unit 30 disposed below the liquid crystal panel 20, a liquid crystal panel 20, and a backlight unit 30. The seated mold frame 32, the liquid crystal panel 20 seated on the mold frame 32, and an upper chassis 25 for capturing the periphery of the backlight unit 30 are provided. However, in FIG. 3, the upper chassis 25 and the mold frame 32 will be omitted for convenience.

The liquid crystal panel 20 has a structure in which an upper plate 22 having a color filter and a lower plate 24 having a thin film transistor are bonded to each other with a liquid crystal interposed therebetween. In addition, the liquid crystal panel 20 further includes upper and lower polarizing sheets 60 and 62 attached to the upper surface of the upper plate 22 and the rear surface of the lower plate 24, respectively, as shown in FIG. 3. In the liquid crystal panel 20, liquid crystal cells driven independently by a thin film transistor are arranged in a matrix form, and each of the liquid crystal cells has a common voltage supplied to the common electrode and a data signal supplied to the pixel electrode through the thin film transistor. The image is displayed by controlling the light transmittance by controlling the liquid crystal array in accordance with the difference voltage. In this case, since the liquid crystal panel 20 is a non-light emitting device, light generated from the backlight unit 30 is used.

In addition, a flexible printed circuit board is mounted on a non-display portion of the lower plate 24 protruding from the driving IC 26 for driving the liquid crystal panel 20, and supplies a driving signal from the outside to the driving IC 26. A printed circuit board (FPC) 28 is connected to one side of the lower plate 24. The driving IC 26 drives the liquid crystal panel 20 using an external driving signal input from the FPC 28. In the drawing, only the case where the driving IC 26 is connected to the lower plate 24 in the form of a chip on glass (COG) method, but may be connected in other ways such as a chip on film (COF) or a tape carrier package (TCP). . It is also possible for the driving IC 26 to be formed on the lower plate 24 together with the thin film transistor in the wiring formation process.

The backlight unit 30 is mounted on the LED circuit board 42 to move the light source unit 40 including the LED 44 to generate light, and the light incident from the LED 44 toward the liquid crystal panel 20. The light guide plate 36, the reflective sheet 34 reflecting the light traveling to the lower portion of the light guide plate 36, and the plurality of optical sheets that collect and diffuse the incident cut light from the light guide plate 36 to the liquid crystal panel 20. (38).

The light source unit 40 has an LED 44 mounted on the top or the back of the LED circuit board 42, which is shown only in the case where it is mounted on the back. In addition, an FPC 46 for supplying a drive signal from the outside is connected to the LED circuit board 42. The LED 44 is driven by driving signals via the FPC 46 and the LED circuit board 42 to generate light.

The light guide plate 36 converts light having an optical distribution in the form of a line light source generated from the LED 44 into light having an optical distribution in the form of a surface light source. As the light guide plate 36, a wedge type plate or a parallel flat plate may be used. The light guide plate 36 may be disposed to be spaced apart from or in contact with the light source unit 40 at a predetermined interval, or may be partially overlapped with the light source unit 40.

The reflective sheet 34 has a high light reflectance and serves to reduce light loss by re-reflecting light incident through the rear surface of the light guide plate 36 toward the light guide plate 36.

The plurality of optical sheets 38 include a diffusion sheet, a brightness enhancing sheet, a polarizing sheet, and the like, and are disposed on the light guide plate 36 to uniform the luminance distribution of the light emitted from the light guide plate 36 and improve light efficiency.

In addition, the backlight unit 30 is mounted on a seating portion provided inside the mold frame 32. The LED circuit board 42 is mounted on the circuit board seating portion provided on one side of the mold frame 32, and the LED 44 mounted on the rear surface of the LED circuit board 42 in the groove provided between the circuit board seating portions. Is inserted. The reflective sheet 34, the light guide plate 36, and the optical sheet 38 are stacked and seated in a sheet seating portion surrounding the periphery of the mold frame 32.

Then, the liquid crystal panel 20 is seated on the mold frame 32 in which the backlight unit 30 is accommodated, and the upper chassis 25 is fastened thereon, so that peripheral portions of the liquid crystal panel 20 and the backlight unit 30 are formed. Captured by the upper chassis 25. In this case, the FPC 28 attached to the liquid crystal panel 20 is bent backwards as shown in FIG. 3 and positioned on the rear surface of the backlight unit 30. In addition, the liquid crystal panel 20 may be attached and fixed to the upper optical sheet 38 of the backlight unit 30 through a double-sided tape surrounding the peripheral portion. Here, the double-sided tape serves to block light leakage through the peripheral portion of the optical sheet 38 by using a dark color such as black. The mold frame 32 and the upper chassis 25 prevent the flow of the liquid crystal panel 20 and the backlight unit 30 accommodated therein, and serve to protect against external impact.

In addition, the liquid crystal display module of the present invention further includes at least one blocking film for blocking light leakage that travels upward from the light source unit 40 toward the light guide plate 36.

For example, the first blocking film 50 is attached to the back of the liquid crystal panel 20 positioned above the light source unit 40, that is, to the back of the non-display portion of the lower plate 24. The first blocking film 50 is formed wider than the light source unit 40 so as to block all light traveling upward from the light source unit 40 without interfering with the image display part of the liquid crystal panel 20. In addition, when the LED 44 is mounted on the rear surface of the LED circuit board 42, the second blocking film 52 is attached to the upper surface of the LED circuit board 42. In this case, the first and second blocking films 50 and 52 may be attached to each of the liquid crystal panel 20 and the LED circuit board 42 by having an adhesive surface on one or both surfaces thereof. As the first and second blocking films 50 and 52, various tapes capable of blocking light such as dark colored tapes that block light, such as black, and metal tapes such as aluminum or copper foil, may be used. have. In this case, the first and second blocking films 50 and 52 are preferably thin so as not to affect the module thickness or the horizontality of the liquid crystal panel 20. As shown in FIG. 3, the first and second blocking films 50 and 52 may be thinner than the lower polarizing sheet 62. It is preferable to form thin. In addition, the first blocking film 50 attached to the rear surface of the liquid crystal panel 20 has a wider width than the second blocking film 52 attached to the upper surface of the LED circuit board 42. This is to block light leakage between the second blocking film 42 and the optical sheet 38 defined by the width of the LED circuit board 42. The second blocking film 42 has a wide width adjacent to the lower polarizing sheet 62 while blocking all of the non-display portions facing the light source unit 40, thereby advancing from the light source unit 40 to the liquid crystal panel 20. The light leakage can be completely blocked.

As described above, the liquid crystal display module according to the present invention includes a blocking film on the rear surface of the liquid crystal panel facing the light source unit and / or on the upper surface of the light source unit to block light leakage that proceeds upward from the light source unit, thereby causing image quality due to light leakage. The fall can be prevented.

In the detailed description of the present invention described above with reference to the preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge of the present invention described in the claims to be described later It will be understood that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

A liquid crystal panel which displays an image; A backlight unit including a light source unit for generating light and supplying light generated by the light source unit to the liquid crystal panel; And a first blocking film attached to a rear surface of the liquid crystal panel facing the light source unit to block light from the light source unit. The method of claim 1, And a second blocking film attached to an upper surface of the light source unit. The method of claim 1, The first blocking film has a thickness thinner than that of the polarizing sheet attached to the rear surface of the liquid crystal panel. The method of claim 2, The first blocking film has a wider width than the second blocking film. The method of claim 2, The light source unit A light emitting diode for generating the light; And a circuit board on which the light emitting diode is mounted. The method of claim 5, And the second blocking film is attached to the circuit board. The method of claim 1, The first blocking film has a larger area than the light source unit. The method of claim 3, wherein And the first blocking film is widely attached to a rear surface of the non-display unit facing the light source unit of the liquid crystal panel so as to be adjacent to the polarizing sheet.

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