KR100877868B1 - Backlight unit - Google Patents

Abstract

The present invention relates to a liquid crystal display device, comprising: a mold frame having an open interior; A light emitting diode disposed at one end of the mold frame; A light guide member accommodated in the mold frame; An optical sheet unit disposed on the light guide member, and a color sensor provided at a position of the light guide portion of the light guide member.

LCD, Backlight Unit, Color Sensor

Description

Backlight unit

1 is an exploded perspective view of a liquid crystal display according to a first embodiment.

FIG. 2 is an exploded perspective view of the mold frame, the reflective sheet, and the main substrate of FIG. 1. FIG.

3 is a combined rear view of the liquid crystal display according to the first embodiment.

4 is a cross-sectional view taken along line II ′ of FIG. 3.

5 is an enlarged view of a portion C of FIG. 4;

6 is an exploded perspective view of a liquid crystal display according to a second embodiment.

FIG. 7 is an exploded perspective view of the mold frame, the reflective sheet, and the main substrate of FIG. 6. FIG.

8 is a combined rear view of the liquid crystal display according to the second embodiment.

FIG. 9 is a cross-sectional view taken along line II-II 'of FIG. 7.

FIG. 10 is an enlarged view of a portion D of FIG. 9; FIG.

<Explanation of symbols for the main parts of the drawings>

10,100: liquid crystal display device 11111: polarizer

12,112: liquid crystal panel 20,120: side light blocking member

30,130: optical sheet portion 40,140: light guide member

41,141: light emitting part 42,142: flexible substrate

43,143: light emitting diode 50,150: mold frame

57: sensor substrate cover 58: substrate support projection

59: light guide groove 60, 160: backlight unit

70,170: main board 72,172: sensor board

74: substrate support groove 80,180: color sensor

150a: Sensor storage groove

The present invention relates to a backlight unit and a liquid crystal display device having the same.

Recently released mobile communication terminals have enhanced a multimedia function such as a video service, a video communication, a camera and the like through a wireless internet, and have a large screen display device for providing a multimedia video screen.

As a display device of such a mobile communication terminal, a liquid crystal display (hereinafter referred to as LCD) element is mainly used. Since the LCD cannot emit light by itself, a back light unit using a light emitting diode is installed on the back of the LCD panel, and the light generated from the backlight is transferred to the liquid crystal layer of the LCD panel, and the red, blue, and green ( Hereinafter, the color is expressed by passing through a color filter including 'R / G / B /'.

In this case, the light emitting diode used in the backlight unit mainly uses a light emitting diode that emits white light by applying a yellow phosphor to a blue light emitting device.

However, the white light emitting diodes that generate light in the backlight unit do not include R / G / B wavelength characteristics, which are three primary colors of light used in the color filter, to reduce the color reproducibility of the liquid crystal display.

Therefore, in recent years, a backlight unit using a white light emitting diode including both R / G / B wavelength characteristics has been developed by mounting an R / G / B light emitting device in one package, but using such a R / G / B light emitting diode The liquid crystal display device employing the backlight unit has a problem in that the luminance of each of the R / G / B light emitting elements changes according to an external environment such as time and temperature, and thus the color balance is broken.

The present invention provides a backlight unit having a color sensor for detecting R / G / B at or near the light guide member of the light guide member, and a liquid crystal display having the same.

According to an exemplary embodiment of the present invention, a liquid crystal display may include a mold frame having an open interior; A light emitting diode disposed at one end of the mold frame; A light guide member accommodated in the mold frame; It includes an optical sheet disposed on the light guide member, and a color sensor provided at the light guide portion of the light guide member.

Liquid crystal display according to an embodiment of the present invention, the mold frame is open inside; An R / G / B light emitting diode disposed at one end of the mold frame; A light guide member accommodated in the mold frame; An optical sheet part disposed on the light guide member; And a color sensor disposed at the light guide portion of the light guide member, and a display panel disposed on the optical sheet portion.

Hereinafter, a liquid crystal display according to embodiments will be described with reference to the accompanying drawings.

1 is an exploded perspective view of a liquid crystal display according to a first embodiment, and FIG. 2 is an exploded perspective view of a mold frame, a reflective sheet, and a main substrate according to the first embodiment.

1 and 2, the liquid crystal display 10 includes an upper / lower polarizer 11, a liquid crystal panel 12, a backlight unit 60, and a main substrate 70.

In the liquid crystal panel 12, a liquid crystal layer is formed between the TFT substrate and the color filter substrate, and upper and lower polarizing plates 11 are attached to both surfaces thereof to polarize incident light.

The backlight unit 60 includes a side light blocking member 20, an optical sheet unit 30, a light guide member 40, a light emitting unit 41, a mold frame 50, and a reflective sheet 53.

The side light blocking member 20 may be formed of a double-sided black tape, and may be attached between the liquid crystal panel 12 and the mold frame 50 to block light leaking into a region other than the light emitting region 21. In addition, both sides of the side light blocking member 20 may be attached to the circumferential surface of the lower polarizing plate of the liquid crystal panel 12 and the locking step 51 of the mold frame 50.

The optical sheet unit 30 may have one or more optical sheets stacked on the light guide member 40. The optical sheet unit 30 may be stacked, for example, the diffusion sheet 31, the prism sheets 32 and 33, and the protective sheet 34, and the diffusion sheet 31 diffuses the incident light. The prism sheets 32 and 33 may be composed of one or more prism sheets, for example, a horizontal and / or vertical prism sheet and a brightness enhancing film, to focus the diffused light into the light emitting region. The protective sheet 34 protects the prism acid on the prism sheet.

The light guide member 40 uniformly irradiates the light emitted from the light emitting diode 43 of the light emitting part 41 toward the liquid crystal panel. That is, it is emitted by the surface light source.

The light emitting part 41 includes a flexible substrate 42 and a light emitting diode 43, and at least one light emitting diode 43 is mounted on the flexible substrate 42, and a driving signal is supplied through one terminal part 46. Take input. Here, the substrate 42 may also be configured by a hard PCB or other electrical connection means, and the light emitting diode 43 may include a R / G / B light emitting diode chip as a single package or each as a separate package. It may be configured.

The reflective sheet 53 attached to the lower portion of the light guide member 40 reflects the light transmitted from the light guide member 40 again.

In addition, the mold frame 50 has an open inside, and locking jaws 51 and 54 are formed around the mold frame 50. The light guide member 40 and the light emitting part 41 are supported and received by the locking projections 51 and 54 in the mold frame, and the optical sheet part 30 is disposed above the light guide member 40. ) Is laminated and the side light shielding member 20 is attached to the outside thereof, and the reflective sheet 53 is attached to the lower portion of the light guide member 40 to complete the backlight unit 60. The liquid crystal panel 12 is coupled to the upper side of the optical sheet unit 30 of the backlight unit 60.

The main substrate 70 is mounted behind the rear reflective sheet 53 of the mold frame 50. The main substrate 70 may be formed of a flexible substrate or a hard PCB, and a sub substrate 71 for driving the liquid crystal panel 12 is provided on one side thereof, and the flexible substrate 42 of the light emitting part 41 is provided. ).

In addition, a sensor substrate 72 is formed at the other corner portion (eg, left and right corners) of the main substrate 70, and the luminance of each red / green / blue light emitting diode 43 is provided on the upper surface of the sensor substrate 72. A color sensor 80 for detecting each is mounted, and a substrate support groove 74 is formed around the sensor substrate.

Specifically, referring to FIG. 2, a sensor substrate cover 57 is formed at a bottom surface corner of the mold frame 50, and the mold frame 50 and the light guide portion A2 of the light guide member 40 contact each other. The light guide groove 59 for guiding light is formed in the corner portion. Here, the light guide groove 59 is formed to be inclined so that some light guided by the light guide member 40 can escape through the light guide portion.

In addition, a sensor support protrusion 58 protruding downward is formed in the sensor substrate cover 57. The sensor substrate cover 57 may have a thickness greater than that of the color sensor 80, and the width and length of the sensor substrate cover 57 may be longer than the width and length of the color sensor 80.

In addition, the corner 53a of the reflective sheet 53 placed between the mold frame 50 and the main substrate 70 is cut into a predetermined shape, for example, an “L” shape, so that the light guide corner of the light guide member 40 is cut. Allow parts to be exposed to the outside.

The combination process of the color sensor installation structure is as follows. FIG. 3 is a combined rear view of the liquid crystal display according to the first embodiment, FIG. 4 is a cross-sectional view taken along line II ′, and FIG. 5 is an enlarged view of portion C of FIG. 4.

1 and 3 to 5, the reflective sheet 53 and the main substrate 70 are stacked on the rear surface of the mold frame 50. The sensor substrate 72 of the main substrate 70 is located at the corner of the mold frame 50, and the substrate support groove 74 of the sensor substrate 72 is disposed in the substrate support protrusion 58 of the sensor substrate cover 57. Is fitted. Accordingly, the sensor substrate 72 is suppressed from being exposed or flowed out of the mold frame.

In this case, the sensor substrate 72 is spaced apart from the rear surface of the reflective sheet 53 or the mold frame 50 and seated on the sensor substrate cover 57. At this time, the flexible connection portion 73 is formed between the main substrate 70 and the sensor substrate 72 so that the movement of the sensor substrate 72 can be facilitated by the space.

In addition, the color sensor 80 is positioned inside the sensor substrate cover 57. At this time, the color sensor 80 is guided by the light guide portion and the light guide groove 59 of the light guide member 40, as shown in Figure 5 to obtain the light intensity of each R / G / B light emitting diode Each will be detected. At this time, the CMOS sensor 81 is positioned inside the color sensor 80 and receives light through the glass substrate 81 outside the CCD or the CMOS sensor.

In addition, an adhesive member (not shown) may be attached to the corner portion of the reflective sheet 53 so as to support the sensor substrate 72 so that the sensor substrate 72 may be in close contact with the reflective sheet 53.

In the initial stage of power supply, the R / G / B light-emitting diode 43 is sequentially turned on by the drive signal of the main substrate 70, and then the generated R / G / B light is driven by the light guide member 40. It is guided and input to the color sensor 80 through the light guide groove 59 of the light processing unit. In this case, the sensor substrate cover 57 also performs a function of blocking external light from entering the color sensor 80.

Accordingly, the color sensor 80 detects an electrical signal corresponding to the brightness of the input light and then transmits the electrical signal to the main board 70 so that the brightness of the R / G / B light is based on the main board 70. Each color correction is performed so that brightness can be achieved. When the color correction for the R / G / B light emitting diode is completed, the driving current value at that time is stored and the entire light emitting diode is driven to maintain the color coordinates of the backlight unit.

Second Embodiment

6 is an exploded perspective view of a liquid crystal display according to a second embodiment, and FIG. 7 is an exploded perspective view of a mold frame and a reflective sheet according to the second embodiment.

6 and 7, the liquid crystal display device 100 includes an upper / lower polarizer 111, a liquid crystal panel 112, a backlight unit 160, and a main substrate 170.

The liquid crystal panel 112 has a liquid crystal layer formed between the TFT substrate and the color filter substrate, and upper and lower polarizers 111 are attached to both surfaces thereof to polarize the incident light.

The backlight unit 160 includes a side light blocking member 120, an optical sheet unit 130, a light guide member 140, a light emitting unit 141, a mold frame 150, and a reflective sheet 153.

The side light blocking member 120 may be formed of a double-sided black tape, and may be attached between the liquid crystal panel 112 and the mold frame 150 to block light leaking into a region other than the light emitting region 121. In addition, both sides of the side light blocking member 120 may be attached to the peripheral surface of the lower polarizer of the liquid crystal panel 112 and the locking step 151 of the mold frame 150.

The optical sheet unit 130 is formed by stacking one or more sheets on the light guide member 140. For example, the diffusion sheet 131, the prism sheets 132 and 133, and the protective sheet 134 may be sequentially stacked. Here, the diffusion sheet 131 diffuses the incident light, and the prism sheets 132 and 133 may be formed of one or more prism sheets, for example, horizontal and / or vertical prism sheets, and brightness enhancement films. The diffused light is focused to the light emitting area. The protective sheet 134 protects the prism acid on the prism sheet.

The light guide member 140 uniformly irradiates the light emitted from the light emitting diode 143 of the light emitting unit 141 toward the liquid crystal panel. That is, it is emitted by the surface light source.

The light emitting unit 141 includes a flexible substrate 142 and a light emitting diode 143, and at least one light emitting diode 143 is mounted on the flexible substrate 142 and transmits a driving signal through one terminal unit 146. Take input. Here, the substrate 142 may also be configured as a hard PCB or other electrical connection means, the light emitting diode 143 is a R / G / B LED chip is composed of a single package, each LED chip is an independent package It can be configured as.

The reflective sheet 153 attached to the lower portion of the light guide member 140 re-reflects the light transmitted from the light guide member 140.

In addition, the mold frame 150 has an open inside, and locking jaws 151 and 154 are formed around the inside of the mold frame 150. The light emitting part 141 and the light guide member 140 are coupled to one side and the other side of the mold frame in a state of being supported by the locking projections 151 and 154. In addition, the optical sheet part 130 is stacked on the upper part of the light guide member 140 and the side light blocking member 120 is attached to the outside thereof, and the reflective sheet 153 is attached to the lower part of the light guide member 140. The backlight unit 160 is completed. The liquid crystal panel 112 is coupled to the upper side of the optical sheet unit 130 of the backlight unit 160.

The main substrate 170 is mounted behind the rear reflective sheet 153 of the mold frame 150. The main substrate 170 may be formed of a flexible substrate or a hard PCB, and a sub substrate 171 for driving the liquid crystal panel 112 is provided at one side thereof, and the flexible substrate 142 of the light emitting unit 141 is provided. ).

The color sensor 180 is provided inside the backlight unit in the liquid crystal display to detect the luminance of each R / G / B light emitting diode, and then perform color correction so as to become a reference luminance.

In addition, a sensor substrate 172 is formed at the other corner portion (eg, left and right corners) of the main substrate 170, and the luminance of each R / G / B light emitting diode 143 is provided on the upper surface of the sensor substrate 172. The color sensor 180 for detecting each is mounted.

In addition, a sensor accommodating groove 150a is formed at the other corner (eg, the left corner or the right corner) of the mold frame 150 to secure a space in which the color sensor 180 can be accommodated, and the sensor accommodating groove ( Corner portions of the optical sheet portion 130 and the light guide portion A2 of the light guide member 140 corresponding to 150a are cut. That is, the other end corners of the diffusion sheet 131, the prism sheets 132 and 133, and the protective sheet 134 of the optical sheet unit 130 have a predetermined shape, for example, L-shaped cutting grooves 131a, 132a, 133a, and 134a. These are formed, respectively, and the cutting groove 140a is formed in the light-corner corner part of the light guide member 140. As shown in FIG. The cutting groove 140a may be formed from the light guide member 140 to the prism sheets 132 and 133 or the protective sheet 134 according to the thickness of the color sensor 180.

The cutting grooves 131a, 132a, 133a, 134a, and 140a secure a space for accommodating the color sensor 80 together with the sensor accommodating groove 50a.

In addition, a cutting groove 153a into which the color sensor 180 can be inserted into the sensor accommodating groove 150a is formed in a predetermined shape, for example, an “L” shape, at the other corner of the reflective sheet 153.

The combination process of the color sensor installation structure is as follows. FIG. 8 is a combined rear view of the liquid crystal display according to the second exemplary embodiment, FIG. 9 is a cross-sectional view of II-II ′, and FIG. 10 is an enlarged view of portion D of FIG. 9.

6 and 8 to 10, the reflective sheet 153 is attached to the rear surface of the mold frame 150, and the main substrate 170 is attached to the rear surface of the reflective sheet. In this case, the main substrate 170 and the sensor substrate 172 connected to the end thereof are placed on the same plane, and the color sensor 180 mounted on the upper surface of the sensor substrate 172 is formed of the mold frame 150. It is accommodated in the sensor accommodating groove 150a. In this case, the color sensor 180 is placed in the sensor accommodating groove 150a, the optical sheet unit 130, and the cutting grooves 131a, 132a, 133a, 134a, and 140a of the light guide member 140.

In this case, as shown in FIG. 10, the color sensor 180 receives light guided by the light guide member 140 and light diffused and collected by the optical sheet unit 130, thereby emitting R / G / B light. The intensity of light of each diode is detected. At this time, the color sensor 180 is a CCD or CMOS sensor is located inside, and receives the light through the glass substrate 181 on the outside.

In addition, an adhesive member (not shown) may be attached to a corner portion of the reflective sheet 153 so that the sensor substrate 172 may be in close contact with the reflective sheet 153.

In the initial stage of power supply, the R / G / B light emitting diode 143 is sequentially turned on by the drive signal of the main substrate 170, and then the generated red / green / blue light is generated by the light guide member 140 and the optical. The color sensor 180 is input along the sheet unit 130. Accordingly, the color sensor 180 detects an electrical signal corresponding to the brightness of the input light and then transmits the electrical signal to the main board 170 so that the brightness of the red / green / blue light is based on the main board 170. Each color correction is performed so that brightness can be achieved. When the color correction for the R / G / B light emitting diode is completed, the driving current value at that time is stored and the entire light emitting diode is driven to maintain the color coordinates of the backlight unit.

Although the above description has been made with reference to the embodiments, these are merely examples and are not intended to limit the present invention, and those of ordinary skill in the art to which the present invention pertains should not be exemplified above without departing from the essential characteristics of the present invention. It will be appreciated that many variations and applications are possible. For example, each component shown in detail in the embodiment of the present invention may be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the light unit and the liquid crystal display having the same according to an embodiment of the present invention, a sensor for detecting the light intensity of each R / G / B light emitting diode is provided under the backlight unit to correct the light intensity of each diode. As a result, the color balance of the liquid crystal display device can be kept constant, thereby realizing a liquid crystal display device having high color reproducibility and color balance.

Claims (12)

delete delete delete delete delete A mold frame open inside; A light guide member accommodated in the mold frame; A light emitting diode disposed on one side of the light guide member; An optical sheet part disposed on the light guide member; A color sensor disposed to correspond to a part of a corner of the other light facing part of the light guide member; A reflective sheet formed on a rear surface of the light guide member and having a corner portion of the other side thereof cut; It includes a main substrate formed on the back of the reflective sheet, The light emitting diode includes a red, green, blue light emitting diode, The backlight unit includes a sensor substrate cover formed to support the periphery of the sensor substrate, and a protrusion and a groove formed to correspond to each other on the sensor substrate cover and the sensor substrate to prevent flow of the sensor substrate at some corners of the other side of the mold frame. . delete delete A mold frame open inside; A light guide member accommodated in the mold frame; A light emitting diode disposed on one side of the light guide member; An optical sheet part disposed on the light guide member; It includes a color sensor disposed to correspond to a part of the corner of the other large light portion of the light guide member, The light emitting diode includes a red, green, blue light emitting diode, The color sensor is disposed at a part of the other side of the inside of the mold frame to sense the light exiting to the other side of the light guide portion and the optical sheet of the light guide member, And a sensor accommodating groove formed at a part of the other side of the inside of the mold frame, at a part of the other side of the light guide member and the optical sheet to accommodate the color sensor. delete The method of claim 9, The optical sheet portion includes a diffusion sheet, at least one prism sheet positioned on the diffusion sheet, and a protective sheet positioned on the prism sheet, And the sensor accommodating groove is formed in some or all sheets of the optical sheet part. delete

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