KR20140073191A - 3D Display Including Back Light Unit Having Light Profile For Wide View Angle - Google Patents

Abstract

The present invention relates to a backlight unit having a wide viewing angle profile and a 3D image display device including same. The backlight unit according to the present invention includes a positive vertical viewing angle (θ=0); a front viewing angle range (0<θ<θ1) defined as a range between first angles (θ=θ1) in first and second directions from the positive vertical viewing angle; and a wide viewing angle range defined as a range between second angles (θ=θ2) in the first and second directions from the first angle, wherein the backlight emitted in the wide viewing angle range has a profile that the brightness thereof is larger than that of the backlight emitted in the front viewing angle range.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a three-dimensional image display device having a backlight unit having a wide viewing angle optical profile,

The present invention relates to a stereoscopic image display device having a backlight unit having a wide viewing angle profile. More particularly, the present invention relates to a stereoscopic image display apparatus having a backlight unit having an optical profile for compensating for a luminance drop due to a double black strip in a wide viewing angle range of a stereoscopic image display apparatus using a patterned retarder system.

2. Description of the Related Art In recent years, a display device capable of selectively implementing a 2D image and a 3D image has been emerging due to the development of various video contents. For 3D image implementation, the display device uses either a stereoscopic technique or an autostereoscopic technique.

As an example of the double-eyepiece system, there is a three-dimensional image display apparatus in which a patterned retarder is disposed on a display panel. The three-dimensional image display apparatus realizes a 3D image by using the polarization characteristics of the patterned retarder and the polarization characteristics of the polarizing glasses worn by the user, It has an advantage that the torque is small and the luminance is excellent and the image quality is excellent.

1 is an exploded perspective view showing a structure of a conventional three-dimensional image system of a pattern-retarder type. The three-dimensional image system of the pattern-dependent retarder method utilizes the polarization characteristics of the patterned retarder PR disposed on the display panel DP and the polarization characteristics of the polarizing glasses PG worn by the user Thereby realizing a stereoscopic image.

The pattern-reliader-type three-dimensional imaging system includes a display panel (DP) for realizing a 2D or 3D image, a patterned retarder (PR) attached to the front surface of the display panel (DP) And the like. The display panel DP is a display device for displaying a 2D image and 3D image data and may be a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (Plasma Display Panel) PDP), and flat panel display devices such as electroluminescence devices (EL) and electrophoresis (EPD) devices including an inorganic electroluminescent device and an organic light emitting diode (OLED) . Hereinafter, the display panel DP will be described mainly with reference to the display panel of the liquid crystal display element.

The display panel DP includes liquid crystal cells arranged in a matrix form by an intersection structure of data wirings and gate wirings. A pixel array including data wirings, gate wirings, TFTs, pixel electrodes, and storage capacitors is formed on the lower glass substrate SL of the display panel DP. The liquid crystal cells are driven by the electric field between the pixel electrodes connected to the TFT and the common electrode. On the upper glass substrate SU of the display panel DP, a black matrix, a color filter, and a common electrode are formed. An upper polarizing film PU and a lower polarizing film PL are attached to the outer sides of the upper glass substrate SU and the lower glass substrate SL of the display panel DP.

The pattern reliader PR is attached to the outside of the upper polarizing film PU of the display panel DP. The pattern reliader PR has unit retarders corresponding to each line whose basic unit is one row of pixels arranged in the horizontal direction of the display panel DP. For example, a unit retarder is allocated corresponding to a region of pixels commonly connected to each gate line. Particularly, the first retarder RT1 is assigned to the odd number lines of the pattern reliader PR and the second retarder RT2 is allocated to the even lines of the pattern reliader PR do. The first retractor RT1 transmits the first circularly polarized light by delaying the phase value of light from the display panel DP by +? / 4 (where? Is the wavelength of light). The second retarder RT2 delays the phase value of light from the display panel DP by -λ / 4 (actually, by 3? / 4) to transmit the second circularly polarized light. The light transmission axis of the first retarder RT1 and the light transmission axis of the second retarder RT2 are orthogonal to each other.

For example, the first retarder RT1 of the patterned retarder PR may be implemented to pass only the left-handed circularly polarized light. And the second retarder RT2 may be implemented with a polarization filter to pass only right circularly polarized light. Therefore, the light of the image displayed on the odd line of the display panel DP passes through the first retarder RT1 and is converted into the first circularly polarized light (i.e., the left circularly polarized light) The light of the displayed image passes through the second retarder RT2 and is converted into second circularly polarized light (i.e., right circularly polarized light).

The polarizing glasses PG are provided with a left eye shading LG having a first polarizing filter P1 and a right eye shading RG having a second polarizing filter P2. The first polarizing filter P1 has the same polarization characteristic as the first retarder RT1 of the pattern retarder PR. The second polarizing filter P2 has the same polarization characteristic as the second retarder RT2 of the pattern retarder PR. For example, the first polarizing filter P1 of the polarizing glasses PG can be selected as a left circular polarization filter, and the second polarizing filter P2 of the polarizing glasses PG can be selected as a right circularly polarizing filter.

In such a structure, a three-dimensional image can be realized by displaying the left eye image in the pixels corresponding to the first retarder RT1 and the right eye image in the pixels corresponding to the second retarder RT2. Thus, the stereoscopic image display apparatus as shown in FIG. 1 can differentiate the polarization characteristic of the left eye image and the polarization characteristic of the right eye image, thereby realizing a 3D image by spatially dividing the left eye image and the right eye image viewed by the user.

In the 3D image display device using the film-type pattern-type retarder, the left-eye image and the right-eye image are alternately displayed in units of horizontal pixel columns, so that a cross-talk phenomenon may occur in the upper and lower viewing angles . FIG. 2 is a cross-sectional view taken along the cutting line A-A 'of FIG. 1, showing a case where crosstalk occurs in the 3D image display apparatus of FIG.

Referring to FIG. 2, when viewing from above (or below) the front direction, the left eye image L1 and the right eye image R1 can be simultaneously output through the first retarder RT1. As a result, a crosstalk phenomenon occurs simultaneously in which the left eye image L1 and the right eye image R1 pass simultaneously through the left eye window LG of the polarizing glasses PG. Although the black matrix BM is formed for each pixel unit constituting the flat panel display device, the size of the black matrix BM does not have a sufficient size to solve the crosstalk.

In the stereoscopic image display apparatus, it is preferable that the left eye image has a structure in which the left eye image is irradiated only with the right eye, and the right eye image is irradiated with only the right eye. However, the viewer is not fixed at the front of the display device, but a plurality of viewers may be distributed within a certain range, and a viewer may view the images while changing positions. Therefore, it is important to have a structure that prevents cross-talk between the left-eye and right-eye even when the position of the spectator changes.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above problems and to provide a stereoscopic image display apparatus capable of compensating for a reduced luminance in a wide viewing angle range of a patterned retarder type stereoscopic display apparatus having a double black strip structure in order to solve a 3D cross- And a backlight unit. Another object of the present invention is to provide a backlight unit having a light profile having a higher luminance in a wide viewing angle range than a front viewing angle range.

In order to achieve the object of the present invention, a stereoscopic image display apparatus according to the present invention includes a top plate, a black strip disposed on a front surface of the top plate, a black matrix disposed on the back surface of the top plate, A display panel provided with a lower plate which is adhered to and opposed to the upper plate; A normal viewing angle (? = 0), which is disposed on the back surface of the display panel and extends in the normal direction of the front of the display panel; (0 &lt;?&Lt;? ₁ ) defined as a range between a first angle (? =? ₁ ) in the first direction and a second direction at the normal viewing angle; And a wide viewing angle range (? ₁ <? <? ₂ ) defined as a range between the first angle and the second angle (? =? ₂ ) in the first direction and the second direction, Wherein the backlight unit includes a backlight unit having a backlight profile having a luminance greater than a luminance of the backlight emitted in the front viewing angle range, wherein the first angle (? =? ₁ ) , is the angle between the vertical extension, and to each other by extending the one end of one side end and the black strip of the black matrix in the same direction as the front direction first extension line of the display panel, wherein the second angle (θ = θ ₂₎ Is an angle between the first extension line and a second extension line extending from the other end of the black matrix in the opposite direction and the one end of the black strip in the front direction.

Wherein the display panel further comprises a first pattern drifter and a second pattern drifter disposed on the front surface of the upper plate, wherein the black strip is formed between the first pattern drifter and the second pattern drift As shown in FIG.

The backlight profile has a reference value corresponding to a length of the pattern reliader minus a width of the black strip in the front viewing angle range; At the second angle ([theta] = [theta] ₂ ), has a maximum value larger than the reference value; Wherein a difference between the reference value and the maximum value is equal to or greater than a luminance reduction value corresponding to a width of the black matrix; And the brightness of the backlight linearly increases as the angle value increases in the wide viewing angle range.

The backlight profile is characterized by following an M-shaped Gaussian function curve having the maximum value at the second angle.

Wherein the backlight profile includes a first Gaussian function curve having the maximum value at the second angle in the first direction and a second Gaussian function curve having the maximum value at the second angle in the second direction, . &Lt; / RTI &gt;

According to another aspect of the present invention, there is provided a stereoscopic image display device including: a display panel; A normal viewing angle (? = 0), which is disposed on the back surface of the display panel and extends in the normal direction of the front of the display panel; Each of the positive first angle (θ = θ ₁₎ a front viewing angle range (0 <θ <θ ₁ and -θ ₁ <θ <0) is defined as a range from a vertical viewing angle in a first direction and a second direction; And a wide viewing angle range (θ ₁ <θ <θ ₂ -θ and ₂ <θ, which is defined by the first angle in the range between the respective second angle (θ = θ ₂₎ in the first direction and the second direction < -θ ₁ ), wherein the brightness of the backlight emitted in the wide viewing angle range includes a backlight unit having a backlight profile having a value greater than the brightness of the backlight emitted in the front viewing angle range.

Wherein the display panel comprises: an upper plate and a lower plate which are joined together and facing each other; A first pattern reliader and a second pattern drifter disposed on a front surface of the upper plate; A black strip disposed between the first pattern relieving device and the second pattern relieving device; And selectively displaying 2D and 3D images including a black matrix having a width smaller than that of the black strip, disposed on the back surface of the upper plate.

The first angle? =? ₁ is an angle between a vertical extension line of the display panel and a first extension line extending in the front direction from one end of the black matrix and the other end of the black strip in the same direction ; The second angle (? =? ₂ ) is an angle between the first extension line and a second extension line extending from the other end of the black matrix and the one end of the black strip opposite to each other in the front direction .

The backlight profile has a reference value corresponding to a length of the pattern reliader minus a width of the black strip in the front viewing angle range; At the second angle ([theta] = [theta] ₂ ), has a maximum value larger than the reference value; Wherein a difference between the reference value and the maximum value is equal to or greater than a luminance reduction value corresponding to a width of the black matrix; And the brightness of the backlight linearly increases as the angle value increases in the wide viewing angle range.

The backlight profile is characterized by following an M-shaped Gaussian function curve having the maximum value at the second angle.

Wherein the backlight profile includes a first Gaussian function curve having the maximum value at the second angle in the first direction and a second Gaussian function curve having the maximum value at the second angle in the second direction, . &Lt; / RTI &gt;

The backlight unit according to the present invention has an optical profile in which the luminance in the wide viewing angle range by the double black strip has a value at least greater than the luminance in the front viewing angle range. Therefore, the 3D cross-talk can be solved in the stereoscopic display device of the patterned retarder system having the double black strip structure, and at the same time, the luminance at least equal to the front view angle can be ensured even at the wide viewing angle. Further, it is possible to provide a backlight having at least the same luminance as the front viewing angle in a wider viewing angle range outside the wide viewing angle range. The backlight unit according to the present invention provides a backlight unit capable of providing the best display quality in a stereoscopic display device of the pattern-driven retarder system.

FIG. 1 is an exploded perspective view showing the structure of a conventional three-dimensional image system of a pattern-retarder type. FIG.
FIG. 2 is a cross-sectional view taken along the cutting line A-A 'in FIG. 1, showing a case where crosstalk occurs in the 3D image display apparatus of FIG.
3 is a cross-sectional view showing a structure of a 3D image display apparatus further including a black strip for solving the cross-talk in a vertical viewing angle in the front direction according to the present invention.
FIG. 4 is a cross-sectional view of a double black strip structure according to FIG. 3 in detail; FIG.
5 is a cross-sectional view schematically illustrating how the luminance is determined according to the viewing angle change in the stereoscopic image display apparatus of FIG.
6 is a graph showing a luminance distribution according to a change in viewing angle when a backlight having a general optical profile (Kp) is used in the display device according to Figs. 4 and 5. Fig.
FIG. 7 is a graph illustrating a backlight profile for compensating for a rate of decrease in luminance caused by the double black strip structure according to the present invention. FIG.
8 is a graph showing an M-shaped Gaussian function curve obtained by arithmetically combining a first Gaussian function curve and a second Gaussian function curve.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a detailed description of known technologies or configurations related to the present invention will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured.

First, referring to FIG. 3, a stereoscopic image display apparatus in which a black strip (BS) is further added between unit pattern deliters is described to solve the viewing angle problem in the vertical vertical direction on the front surface of the display panel. 3 is a cross-sectional view illustrating a structure of a 3D image display apparatus further including a black strip for solving cross-talk at an upper and lower viewing angle in a front view direction of a display panel according to the present invention.

Referring to FIG. 3, a black strip BM overlapped with the black matrix BM is further formed on the outer surface of the upper substrate SU on which the black matrix BM is formed. The black strip BS is positioned on the optical path in which the right eye image R1 is projected onto the first retractor RT1 so that the right eye image R1 is prevented from being projected onto the first retractor RT1. As a result, when viewing from the front of the display device and moving in the vertical direction, the crosstalk does not occur within a certain range.

Particularly, when the width of the black strip BS is made wider than the width of the black matrix BM and the black strip BS is disposed so as to completely cover the black matrix BM, a wider viewing angle Crosstalk can be effectively prevented in a range of a wide viewing angle). However, since the black strip (BS) and the black matrix (BM) are both observed in the wide viewing angle range, the light shielding area is wider. Therefore, the brightness of the light may be lowered in the wide viewing angle range. That is, there is an advantage in that the 3D crosstalk in the wide viewing angle range is solved by the black matrix (BM) and the black strip (BS) formed on the back and front surfaces of the upper glass substrate, respectively, but the brightness may be lowered.

Hereinafter, with reference to FIGS. 4 to 6, it will be described how the luminance value of a patterned retarder type stereoscopic image display device having a double black strip structure according to the first embodiment of the present invention is. 4 is a cross-sectional view of the double black strip structure of FIG. 3 in detail. FIG. 5 is a cross-sectional view briefly showing how the brightness is determined according to the viewing angle change in the stereoscopic image display apparatus of FIG. 6 is a graph showing a luminance distribution according to a change in viewing angle when a backlight having a general optical profile (Kp) is used in the display device according to Figs. 4 and 5. Fig.

4 is an enlarged view of the structure of a stereoscopic display apparatus having a double black strip structure according to the present invention. The stereoscopic image display device according to the present invention may be a liquid crystal display device having an upper substrate SU, a lower substrate SL and a liquid crystal layer LC interposed therebetween. On the rear surface of the upper substrate SU, a plurality of color filters CF are arranged in a matrix manner in accordance with the pixel arrangement scheme. A black matrix BM is disposed between the respective color filters CF.

And a pattern reliader (PR) arranged on the front surface of the upper substrate, one for each pixel row in the horizontal direction. In particular, the first (left eye) pattern reliader RT1 and the second (right eye pattern) retarder RT2 are alternately arranged. A black stripe (BS) for preventing 3D cross-talk is disposed between the first pattern reliator (RT1) and the second pattern reliator (RT2). However, unlike the black matrix BM arranged in both the horizontal direction and the vertical direction, the black strip BS is disposed only in the horizontal direction.

The black strip BS and the black matrix BM have a structure in which they are overlapped with each other. In particular, the black strip (BS) preferably has a width equal to or greater than the black matrix (BM). The structure in which the black strip BS and the black matrix BM are arranged on the front and rear surfaces of the upper substrate SU in a superimposed manner is referred to as a double black strip structure.

In such a display device having a double black strip structure, the main elements that interfere with the brightness (luminance) of the backlight are the black strip (BS) and the black matrix (BM). Only the black strip BS may be observed, or both the black strip BS and the black matrix BM may be observed, depending on the viewer's position at the front. In addition, a portion of a black matrix (BM) and a black strip (BS) may be observed. It is necessary to divide the viewing angle and the viewing angle range into such areas.

For example, the traveling direction of the vertical extension line VL of the display panel DP, that is, the direction in which [theta] = 0 can be referred to as a normal viewing angle. A line extending from the right end of the black matrix BM to the right end of the black strip BS and continuing in the direction in which the spectator is located can be referred to as a first extension line 100. The line extending from the left end of the black matrix BM to the right end of the black strip BS and continuing in the direction in which the spectator is located can be referred to as a second extended line 200. And a vertical extension line (VL) and a first extension (100) is the angle formed at a first angle (θ = θ _1), the vertical extension line (VL) and a second extension 200 is an angle formed by the second angle (θ = &amp;thetas; ₂ ).

In this state, the viewing angle range 0 <? <? ₁ , which is a region between the normal extension line VL and the first extension line 100, can be regarded as the front viewing angle range. And it may be referred to as the first extension 100 and second extension 200, between the area of the viewing angle (θ) range of θ ₁ <θ <θ ₂ a wide viewing angle range.

In FIG. 4, only the viewing angle with respect to the first direction (upper direction) is shown, but the viewing angle of the patterned retarder according to the present invention is in a vertically symmetrical relationship. In FIG. 4, the viewing angle with respect to the viewing angle in the second direction (downward direction) is omitted for convenience. Therefore, the front view angle range (θ) includes both the 0 <θ <θ ₁ and -θ ₁ <θ <0. Here, the sign (-) does not mean a negative value, but means that the direction is opposite. And the range of the wide viewing angle? Includes both of? ₁ <? <? ₂ and? ₂ <? <-Θ ₁ .

The first angle? ₁ and the second angle? ₂ can be obtained by the thickness of the upper substrate SU, the width of the black matrix BM and the width of the black strip BS. That is, when the thickness of the upper substrate SU is t, the width of the black matrix BM is y, and the width of the black strip BS is y, the first angle? ₁ is determined by the following equation 1 . Further, the second angle? ₂ can be determined by the following equation ( ₂ ).

Referring to FIG. 5, how the luminance varies with the change of the viewing angle will be described. Here, L is the width of the pattern reliader (PR). This corresponds to the length of the pixel. x is the width of the black strip (BS), and y is the width of the black matrix (BM).

Looking at the display panel DP at the front viewing angle range of -θ ₁ <θ <θ ₁ , only the black strip BS is observed. Therefore, the luminance value in the front viewing angle range has a value corresponding to the length of Lx. However, as the viewing angle is gradually increased from the first angle? ₁ , the black matrix (BM) hidden behind the black strip (BS) begins to be seen slightly. Accordingly, the luminance value gradually decreases as the viewing angle is gradually increased from? ₁ . Then, when the viewing angle becomes the second angle? ₂ , both the black strip (BS) and the black matrix (BM) are observed. At least at the second angle of view angle? ₂ , the luminance is most disturbed. That is, the luminance value has a value corresponding to the length of Lxy.

With reference to FIG. 6, the change in the brightness due to the double strip structure will be described according to the change of the viewing angle. In FIG. 6, the solid line curve represents the light profile (Kp) of a typical backlight, and the one-dot chain line curve represents the profile of the luminance varied by the double black strip structure.

A typical backlight profile (Kp) follows a Gaussian function curve. That is, it has a maximum value at a normal viewing angle, and has a backlight profile in which the brightness becomes progressively darker as the viewing angle increases. Particularly, in the front view angle range of -θ ₁ <θ <θ ₁ , the luminance value is close to the maximum value (100%).

The backlight having the profile according to the Gaussian function curve in the backlight unit is irradiated on the display panel and the brightness profile observed by the spectator is reduced by the double black strip structure described in Fig. That is, the luminance corresponding to the width L of the pattern reliader PR corresponding to the pixel length corresponds to 100% of the backlight luminance. Therefore, at the wide viewing angle range of? 1 <? <? 2, the viewing angle gradually increases between the maximum L-x and the minimum L-x-y. For example, it can be linearly reduced between a maximum L-x and a minimum L-x-y. Or may be reduced along the Gaussian function curve between the maximum L-x and the minimum L-x-y.

Importantly, when the backlight profile follows the Gaussian function curve, the luminance profile also has a maximum value that is reduced by a value corresponding to the x value at the backlight maximum value, but does not follow the Gaussian function curve at the same rate as the backlight profile . Rather, the y value further increases the Gaussian reduction rate.

For example, the luminance decay rate (M _? ) At an arbitrary position? ₁ <? <? ₂ within the wide viewing angle range can be expressed by the following equation (3).

Here, a is the length of the black matrix (BM) observed at an arbitrary viewing angle? (? ₁ <? <? ₂ ). For example, when? Is? ₁ , since a is 0, it is (Lx-0) / (Lx). Therefore, the luminance lowering rate M _? Is zero. That is, there is no luminance decreasing rate in the front view angle range. On the other hand, when? Is? ₂ , since a is y, (Lxy) / (Lx) has a minimum value. Therefore, the luminance lowering rate becomes the maximum. That is, the rate of decrease in luminance at? ₂ is the maximum rate of decrease, which can be expressed by the following equation (4).

In Equation (3), the a value is not easily measured. Therefore, using the equation (4), the rate of luminance lowering (M _? ) At an arbitrary position? ₁ <? <? ₂ within the wide viewing angle range can be expressed by the following equation (5).

The present invention provides a backlight unit capable of compensating for a decreased luminance in accordance with the viewing angle direction or the viewing angle range in order to compensate for the luminance lowering rate. That is, in a patterned retarder type stereoscopic image display apparatus having a double black strip structure, a backlight system having a backlight profile compensating for a luminance lowering rate occurring in a wide viewing angle range that reduces 3D crosstalk due to a double black strip structure .

The backlight profile can be adjusted by adjusting the light emission profile of the light source constituting the backlight unit. Alternatively, the light converging or diffusing profile of the light guide plate or the optical film, which is other elements constituting the backlight unit, can be adjusted and adjusted. Therefore, a characteristic of the backlight unit according to the present invention is that it has a specific backlight profile. In particular, the backlight unit according to the present invention is characterized by having a backlight profile that can compensate for the brightness lowered in the viewing angle direction.

Hereinafter, the backlight profile according to the present invention will be described with reference to FIG. FIG. 7 is a graph illustrating a backlight profile for compensating for the rate of decrease in luminance caused by the double black strip structure according to the present invention. The solid curve in Fig. 7 represents the backlight profile according to the present invention. The dotted curve represents a typical backlight profile. And the one-dot chain line represents the luminance profile observed at various viewing angles.

7, the backlight profile according to the present invention is characterized in that the brightness of the backlight emitted in the wide viewing angle range (θ ₁ <θ <θ ₂ ) is within the front viewing angle range (0 <θ <θ ₁ ) And has a value larger than the luminance of the backlight to be emitted. And has a reference value (100%) which is the same luminance value as the maximum luminance of a general backlight unit in the front view angle range. And has a maximum luminance value capable of compensating the maximum luminance lowering rate at the second angle (? ₂ ) having the maximum luminance lowering rate. For convenience, the maximum luminance value is assumed to be 110%. That is, the maximum luminance reduction rate due to the double black strip structure is assumed to be 10%. In the wide viewing angle range, as the angle value increases, the brightness of the backlight preferably increases linearly or Gaussianly from the reference value to the maximum value.

For example, it is preferable to have an M-shaped distribution curve having the maximum luminance at the second angle? ₂ . In particular, it is more preferable to follow an M-shaped Gaussian function curve. Since it follows the Gaussian function curve, it has a profile that gradually decreases as the viewing angle increases or decreases with reference to the maximum luminance value at the second angle? ₂ .

As a result, when observed at various viewing angles of the display panel, a luminance distribution as shown by a one-dot chain line can be obtained. That is, the brightness measured by the black strip (BS) and the black matrix (BM) has a profile lower than that of the backlight. Particularly, in the front viewing angle range (0 &lt;?&Lt;? ₁ ), the luminance is lowered by the black strip BS. Since the luminance degradation due to the black strip (BS) and the black matrix (BM) is compensated by the backlight in the wide viewing angle range (? ₁ <? <? ₂ ), the reference value (100%), which is almost the same as in the front viewing angle range, The bright luminance can be obtained.

Further, a third angle? ₃ , which is the viewing angle direction in which the backlight profile according to the present invention meets the reference value of 100%, occurs. The third angle? ₃ is a viewing angle direction at an angle larger than the second angle? ₂ . In the luminance distribution based on the general backlight profile, the luminance at the third angle is less than half of the maximum value, but the luminance distribution according to the backlight profile according to the present invention has bright luminance close to the reference value (100%). That is, the backlight unit according to the present invention can provide brighter luminance values even in a wider viewing angle range.

The backlight profile following the M-shaped Gaussian function curve according to the present invention has a first Gaussian function curve having a maximum value at the second angle (? ₂ ) in the upper (first) direction and a first Gaussian function curve having the maximum value at the second And a second Gaussian function curve having a maximum value at two angles (? ₂ ). 8 is a graph showing an M-shaped Gaussian function curve obtained by arithmetically combining the first Gaussian function curve GA1 and the second Gaussian function curve GA2.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the present invention should not be limited to the details described in the detailed description, but should be defined by the claims.

DP: display panel SL: lower glass substrate
SU: upper glass substrate PL: lower polarizing film
PU: Upper polarizing film PG: Polarizing glasses
P1: first polarizing filter P2: second polarizing filter
RG: Wan Yongchang LG: left eye
PR: pattern-retarder RT1: first retarder
RT2: second retarder BM: black matrix
BS: Black strip CF: Color filter
L1: (first row) left eye image R1: (first row) right eye image
L2: (second row) left eye image R2: (second row) right eye image
Lp: (M-shaped) Backlight Profile Kp: (Gaussian) Backlight Profile
? ₁ : first angle? ₂ : second angle
VL: vertical extension line 100: first extension line
200: 2nd extension line

Claims (11)

A display panel including a top plate, a black strip disposed on a front surface of the top plate, a black matrix disposed on the back surface of the top plate so as to overlap with the black strip, and a bottom plate cov- ered to be opposed to the top plate; And
A normal viewing angle (? = 0) disposed on the back surface of the display panel and extending in the normal direction of the front of the display panel; (0 &lt;?&Lt;? ₁ ) defined as a range between a first angle (? =? ₁ ) in the first direction and a second direction at the normal viewing angle; And a wide viewing angle range (? ₁ <? <? ₂ ) defined as a range between the first angle and the second angle (? =? ₂ ) in the first direction and the second direction, Wherein the backlight unit includes a backlight unit having a backlight profile having a luminance greater than a luminance of the backlight emitted in the front viewing angle range,
The first angle? =? ₁ is an angle between a vertical extension line of the display panel and a first extension line extending in the front direction from one end of the black matrix and the other end of the black strip in the same direction ,
The second angle (? =? ₂ ) is an angle between the first extension line and a second extension line extending from the other end of the black matrix and the one end of the black strip opposite to each other in the front direction Wherein the stereoscopic image display device is a stereoscopic image display device.
The method according to claim 1,
In the display panel,
Further comprising a first pattern reliader and a second pattern drifter disposed on the front surface of the upper plate,
The black strip may be formed,
Wherein the second pattern driver is disposed between the first pattern driver and the second pattern driver.
The method according to claim 1,
The backlight profile may include:
A reference value corresponding to a length of the pattern reliader minus a width of the black strip in the front viewing angle range;
At the second angle ([theta] = [theta] ₂ ), has a maximum value larger than the reference value;
Wherein a difference between the reference value and the maximum value is equal to or greater than a luminance reduction value corresponding to a width of the black matrix;
And the brightness of the backlight linearly increases as the angle value increases in the wide viewing angle range.
The method of claim 3,
The backlight profile may include:
And an M-shaped Gaussian function curve having the maximum value at the second angle is followed.
The method according to claim 1,
The backlight profile may include:
A first Gaussian function curve having the maximum value at the second angle in the first direction and a second Gaussian function curve having the maximum value at the second angle in the second direction. Dimensional image display device.
Display panel; And
A normal viewing angle (? = 0) disposed on the back surface of the display panel and extending in the normal direction of the front of the display panel; (0 &lt;?&Lt;? ₁ ) defined as a range between a first angle (? =? ₁ ) in the first direction and a second direction at the normal viewing angle; And a wide viewing angle range (? ₁ <? <? ₂ ) defined as a range between the first angle and the second angle (? =? ₂ ) in the first direction and the second direction, Wherein the brightness of the backlight emitted in the viewing angle range includes a backlight unit having a backlight profile having a value larger than the brightness of the backlight emitted in the front viewing angle range.
The method according to claim 6,
Wherein the display panel comprises: an upper plate and a lower plate which are joined together and facing each other;
A first pattern reliader and a second pattern drifter disposed on a front surface of the upper plate;
A black strip disposed between the first pattern relieving device and the second pattern relieving device; And
Wherein the display device selectively displays 2D and 3D images including a black matrix having a width smaller than that of the black strip, disposed on a back surface of the upper plate.
8. The method of claim 7,
The first angle? =? ₁ is an angle between a vertical extension line of the display panel and a first extension line extending in the front direction from one end of the black matrix and the other end of the black strip in the same direction ;
The second angle (? =? ₂ ) is an angle between the first extension line and a second extension line extending from the other end of the black matrix and the one end of the black strip opposite to each other in the front direction Wherein the stereoscopic image display device is a stereoscopic image display device.
9. The method of claim 8,
The backlight profile may include:
A reference value corresponding to a length of the pattern reliader minus a width of the black strip in the front viewing angle range;
At the second angle ([theta] = [theta] ₂ ), has a maximum value larger than the reference value;
Wherein a difference between the reference value and the maximum value is equal to or greater than a luminance reduction value corresponding to a width of the black matrix;
And the brightness of the backlight linearly increases as the angle value increases in the wide viewing angle range.
10. The method of claim 9,
The backlight profile may include:
And an M-shaped Gaussian function curve having the maximum value at the second angle is followed.
9. The method of claim 8,
The backlight profile may include:
A first Gaussian function curve having the maximum value at the second angle in the first direction and a second Gaussian function curve having the maximum value at the second angle in the second direction. Dimensional image display device.

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