KR100589380B1 - Plasma display apparatus capable of enhancing light room contrast - Google Patents

Abstract

The present invention relates to a plasma display device capable of improving clear room contrast. The plasma display panel according to the present invention includes an upper substrate and a lower substrate disposed substantially parallel to each other at arbitrary intervals. A plurality of sustain discharge electrodes are disposed on a lower surface of the upper substrate, and an upper dielectric layer is formed on the lower front surface of the upper substrate while covering the sustain discharge electrodes. In addition, a protective film is coated on the upper dielectric layer. Meanwhile, a plurality of address electrodes are formed on the lower substrate facing the upper substrate, and a lower dielectric layer is formed on the upper front surface of the lower substrate while covering the address electrodes. In addition, a plurality of partition walls forming the discharge space are provided at a predetermined height with the lower dielectric layer, and a phosphor layer is formed in the discharge space. At this time, the upper and lower dielectric layers include a blue pigment. According to the present invention, the clear room contrast in the PDP can be improved without the bias on the color coordinates.

Plasma Display Panel, PDP, Clear Room Contrast, Dielectric, Blue Pigment, Gamma Correction

Description

Plasma display device that can improve contrast in clear room {PLASMA DISPLAY APPARATUS CAPABLE OF ENHANCING LIGHT ROOM CONTRAST}

1 is a schematic diagram of a structure of a plasma display panel according to an embodiment of the present invention.

2 is a view showing a relationship between pigment content ratio and panel reflection luminance in a plasma display panel according to an exemplary embodiment of the present invention.

3 is a view showing a relationship between pigment content versus peak white and clear room contrast in a plasma display panel according to an embodiment of the present invention.

4 is a diagram illustrating color coordinate characteristics of a plasma display panel according to an exemplary embodiment of the present invention.

5 is a block diagram of a plasma display device capable of improving contrast in a clear room according to an exemplary embodiment of the present invention.

6 is a diagram illustrating a gamma correction value in a conventional plasma display device.

7 illustrates a gamma correction value in the plasma display device according to an exemplary embodiment of the present invention.

FIG. 8 is a diagram illustrating sizes of R, G, and B image data output from an image signal processor of the plasma display apparatus of FIG. 5.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (hereinafter referred to as "PDP"), and more particularly, to a plasma display device capable of improving bright room contrast.

The PDP is a display device using a plasma phenomenon, and discharge occurs when at least one potential difference is applied between two spatially separated contacts in a non-vacuum gas atmosphere. This is called a gas discharge phenomenon. PDP is a flat panel display element which applied such gas discharge phenomenon to image display.

In PDP, bright room contrast is referred to as an index for making a bright and clear PDP. Image quality evaluation is performed not only in dark room contrast but also in contrast in bright room. This clear contrast can be expressed as Equation 1 below.

[Equation 1]

Here, the 1% peak luminance refers to the luminance of the portion corresponding to the 1% portion of the panel, and the panel reflection luminance is a luminance value measured when the power is turned off while setting the environment so that the external light condition is 150 lx vertically on the panel surface. Means.

As such, clear contrast is becoming more important as it is used as an image quality evaluation item in PDP, but there is no clear way to improve clear contrast, and PDP which can improve bright contrast in the future to obtain bright and clear screen It is required.

Therefore, the technical problem of this invention is providing the plasma display apparatus which improves a clear room contrast and provides a clear and clear screen.

PDP according to one feature of the present invention for achieving the above object,

An upper substrate and a lower substrate disposed substantially parallel at any interval; A plurality of sustain discharge electrodes disposed on a lower surface of the upper substrate; An upper dielectric layer formed on the entire lower surface of the upper substrate while covering the sustain discharge electrodes; A protective film coated on the upper dielectric layer; A plurality of address electrodes formed on the lower substrate opposite the upper substrate; A lower dielectric layer formed on the entire upper surface of the lower substrate while covering the address electrodes; A plurality of partition walls provided with the lower dielectric layer and having a predetermined height to form a discharge space; And a phosphor layer formed in the discharge space, wherein the upper and lower dielectric layers include a blue pigment.

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In addition, the dielectric layer preferably comprises 0.25% to 2.0% of the blue pigment.

Plasma display device according to another aspect of the present invention,

A PDP comprising a dielectric layer having a blue pigment added thereto to insulate the substrate; And a PDP driver configured to receive an input image signal from an external source and process the signal to match the characteristics of the PDP, and apply the PDP driver to the PDP, wherein the PDP driver is configured to adjust a color coordinate and a white color corresponding to the characteristics of the PDP. And correcting by outputting a corresponding video signal by dropping the weight of the gamma correction value corresponding to the color of the blue pigment added to the dielectric layer of the PDP.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

Hereinafter, a PDP with improved clear contrast in accordance with an embodiment of the present invention will be described.

An embodiment of the present invention is to add a pigment to the dielectric in order to reduce the panel reflection brightness in the PDP and consequently increase the contrast contrast. In particular, a blue pigment participates in a dielectric.

When blue pigment is added to the dielectric, the panel reflection brightness and peak brightness are reduced, but the bright room contrast is improved. In particular, as the content of the blue pigment added to the dielectric increases, the clear room contrast increases. The content of the blue pigment added to the dielectric is preferably 0.25% to 2.0%, but the technical scope of the present invention is not limited thereto, and the content of the blue pigment may be any amount within the range in which the clear color contrast increases due to the increase of the pigment content.

An example of a PDP according to an embodiment of the present invention in which a blue pigment is added to a dielectric is shown in FIG. 1.

As shown in FIG. 1, a PDP according to an embodiment of the present invention includes an upper substrate 100 and a lower substrate 200 disposed substantially parallel to each other at random intervals.

An upper dielectric layer is formed on the lower surface of the upper substrate 100 to cover the plurality of sustain scan electrodes 110 and the sustain scan electrodes 110 on the lower surface of the upper substrate 100, and to add a pigment such as blue. 120 is formed. A passivation layer 130 including MgO is formed on the upper dielectric layer 120.

Meanwhile, a plurality of address electrodes 210 disposed on the lower substrate 200 opposite to the upper substrate 100 orthogonal to the sustain scan electrodes 110 formed on the upper substrate 100 is formed. The dielectric layer 220 is formed on the entire upper surface of the lower substrate 200 while covering the address electrodes 210, and a pigment such as blue is added thereto.

A plurality of barrier ribs 230 are formed on the lower dielectric layer 220 to form a discharge space, and the phosphor layer 240 is formed on the upper side of the lower dielectric layer 220 and the barrier wall 230. .

Hereinafter, examples and comparative examples of the present invention are described. However, the following examples are only examples of the present invention and the present invention is not limited to the following examples.

(Example 1)

On the upper substrate made of soda-lime glass, a sustain scan electrode was formed in a stripe shape using a conventional method using an indium tin oxide conductive material.

Subsequently, a blue pigment was added to the paste of lead-based glass, but the content of the blue pigment relative to the dielectric layer was 0.25%, thereby coating and baking the entire surface of the upper substrate on which the sustain scan electrode was formed to form a dielectric layer.

The upper substrate was manufactured by manufacturing a protective film including MgO on the dielectric layer by using a sputtering method.

(Example 2)

The same procedure as in Example 1 was conducted except that a dielectric layer having a blue pigment content of 0.50% was prepared.

(Example 3)

The same procedure as in Example 1 was carried out except that a dielectric layer having a blue pigment content of 1.0% was prepared.

(Example 4)

The same procedure as in Example 1 was carried out except that a dielectric layer having a blue pigment content of 1.5% was prepared.

(Example 5)

The same procedure as in Example 1 was carried out except that a dielectric layer having a blue pigment content of 2.0% was prepared.

 (Comparative Example 1)

The same procedure as in Example 1 was carried out except that a dielectric layer having a blue pigment content of 0.0%, that is, a dielectric layer without addition of a blue pigment was prepared.

The panel reflection luminance of five PDPs prepared according to Examples 1 to 5 and one PDP prepared according to Comparative Example 1 was measured and shown in the following [Table 1], and the pigment content ratio (B_Pig) to panel reflection was measured. As shown in FIG. 2, the relationship between the luminance Lr and the relationship with the peak white and the clear room contrast are graphically shown as shown in FIG. 3.

[Four 1]

As shown in [Table 1] and FIG. 2, the panel reflection luminance is reduced in Examples 1 to 5 in which the blue pigment is added to the dielectric layer, compared to Comparative Example 1 in which the blue pigment is not added to the dielectric layer. Able to know. In addition, it can be seen that the panel reflection brightness is further reduced as the content of the blue pigment added to the dielectric layers in Examples 1 to 5 increases. That is, it can be seen that the panel reflection brightness is inversely proportional to the blue pigment content. Referring to FIG. 2, the panel reflection brightness and the blue pigment content can be seen as shown in Equation 2 below.

[Equation 2]

Y = 13.23-5.26 × B_Pig

Here, Y is the panel reflection luminance and the unit is cd / m ² , and B_Pig is the content of the blue pigment added to the dielectric layer, which is%.

On the other hand, referring to Figure 3, due to the increase in the content of the blue pigment added to the dielectric layer it can be seen that not only decreases the panel reflection brightness, but also decreases the peak white together, the contrast contrast increases inversely.

For example, in Example 3 in which the blue pigment content of the dielectric layer was applied at 1.0%, the peak white was reduced by about 33.4% compared to the case of Comparative Example 1, but the clear contrast was improved to about 53.4%.

As described above, the PDP according to the embodiment of the present invention can increase the brightness contrast by adding a pigment, especially a blue pigment, to the dielectric layer, thereby providing brighter and clearer picture quality. In addition, since the clear room contrast increases simultaneously with the increase of the content of the added pigment, it is possible to satisfy the required clear room contrast by adjusting the content of the pigment according to the characteristics of the PDP to be produced.

On the other hand, when the blue pigment is added to the dielectric layer of the PDP as in Examples 1 to 5 to improve the clear room contrast, the color coordinates are shifted toward the blue side as shown in FIG. In particular, in FIG. 4, when the content of the blue pigment is increased to 1.0% (2), 1.5% (3) and 2.0% (3) compared to the case in which no blue pigment is added (1: 0.0%), the color coordinate is moved toward the blue color. The problem arises that the bias is greater.

5 is a block diagram of a plasma display device capable of improving contrast in a clear room according to an exemplary embodiment of the present invention.

As shown in FIG. 5, the plasma display device according to an exemplary embodiment of the present invention includes an image signal processor 100, a gamma correction unit 200, an error diffusion unit 300, a memory controller 400, and an address driver 500. ), A sustain scan pulse driving control unit 600, a sustain scan pulse driving unit 700, and a PDP 800.

First, as described above with reference to FIG. 1, the PDP 800 is a PDP that adds a pigment, particularly a blue pigment, to the dielectric layer to improve bright room contrast.

The image signal processor 100 digitizes an image signal input from the outside to generate corresponding digital image data.

The gamma correction unit 200 receives the digital image data output from the image signal processing unit 100 and corrects the gamma values to adjust the color coordinates and the white color corresponding to the characteristics of the PDP 800 to generate and output corresponding image data. . In this case, the gamma correction unit 200 typically gamma-corrects and outputs the corresponding RGB image data according to the gamma correction value shown in FIG. 6 with respect to the input RGB image data. As shown in FIG. 6, in a conventional plasma display apparatus, a panel gamma correction is performed by detecting and setting weights of R, G, and B data satisfying a target color coordinate on a panel with respect to the same data value. In the example, as shown in the accompanying FIG. 7 to correct the bias toward the blue in the color coordinates by adding a pigment, in particular a blue pigment, to the dielectric layer of the PDP 800, the B weight applied to the B image data is lower than the conventional one. Drop.

Meanwhile, the gamma correction unit 200 stores the gamma correction values for the input image data in R, G, and B as shown in FIG. 7 in a specific pattern gamma correction table to input the R, G, and B image data. Corresponding pattern gamma correction values are output so that color coordinates of R, G, and B input image data can be corrected.

When the error diffusion unit 300 receives the image data output from the gamma correction unit 200 and converts the image data into a gray scale that can be expressed by the PDP 800, the error diffusion unit 300 performs diffusion processing on the surrounding pixels.

On the other hand, as shown in FIG. 8, it can be seen that the color coordinates are shifted toward the blue color through the image data output without the gamma value correction by receiving the digital image data output from the image signal processing unit 100.

When the blue pigment is added, the output gradation is saturated too quickly compared to the input gradation compared to the existing panel, and thus the general panel gamma correction method cannot express the gradation properly. This selects only grayscales that can be used through experiments in the actual panel, and uses only input grayscales that produce linear outputs, not input grayscales that produce saturated outputs in the gamma correction unit 200.

The size of the B image data is the same as that of the R and G image data, but the change of the output is more than twice as large as that of the R and G image data. For example, referring to FIG. 8, when the B image data is linearly outputted relative to the input, the R image data is output per input gradation step when the R image data is changed by 4 steps per input gradation step. These eight steps change. In order to solve this problem, the gamma correction unit 200 increases the output gray level of the B image data to N + 1 bits, and the error diffusion unit 300 sets the error value for the B image data to M + 1 bits, thereby reducing the display error. Diffusion processing of the pixels satisfies the level equivalent to the magnitude of the output change for each input gray level of the R and G image data.

Meanwhile, the memory controller 400 generates the subfield data corresponding to the subfield array structure output from the sustain scan pulse driving controller 600 while maintaining the grayscale data output from the error diffusion unit 300.

The address driver 500 generates address data corresponding to the subfield data generated by the memory controller 400 and applies the address data to the address address electrodes A1, A2,... Am of the PDP 800.

The sustain scan pulse driving controller 600 generates a subfield array structure corresponding to the image data output from the gamma corrector 200 and outputs the subfield array structure to the memory controller 500 and the sustain scan pulse driver 700.

The sustain scan pulse driver 700 generates sustain scan pulses and scan pulses based on the subfield array structure output from the sustain scan pulse drive controller 600 to scan electrodes X1, X2, .. Xn of the PDP 800. ) And sustain electrodes Y1, Y2, ..., Yn.

As described above, when the blue pigment is added to the dielectric layer in the PDP 800 to improve the clear room contrast, the gamma correction unit 200 reduces the weight applied to the B image data by gamma correction to reduce the bias toward the blue on the color coordinate. Can be.

In the above, the signal output from the gamma correction unit 200 is directly displayed on the PDP 800 by subfield mapping, but the image data output from the gamma correction unit 200 to suppress power consumption of the PDP 800. Image load by detecting the load rate, calculating the automatic power control (APC) level according to the detected load rate, calculating the maximum number of sustain discharge pulses corresponding to the calculated APC level, the address pulse width of each subfield, etc. It may further include means for field mapping and displaying on the PDP 800.

In addition, in the above description, only the use of a colored dielectric by adding a pigment of a specific color to the dielectric is described, but the technical scope of the present invention is not limited thereto, and the colored dielectric in which the dielectric itself has a specific color is used. It will be readily understood by one skilled in the art that the effect of the present invention as achieved is achieved.

In addition, in the above description, only the correction of the data through the gamma correction of the color coordinate shift problem caused by the use of the colored dielectric in which the pigment is added or the colored dielectric in which the dielectric itself has a specific color has been described. The problem of color coordinate shift caused by using an optical filter containing R / G / B colors or other factors can also be solved by performing data correction through gamma correction as described above. It will also be readily understood by those skilled in the art.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various other changes and modifications are possible.

According to the present invention, the clear room contrast in the PDP can be improved without the bias on the color coordinates.

Claims (9)

delete delete delete A plasma display panel including a dielectric layer having a blue pigment added thereto to insulate the substrate; And Plasma display panel driver for receiving an input image signal from the outside and processing the signal to match the characteristics of the plasma display panel to apply to the plasma display panel Including; The plasma display panel driver, A weight of the gamma correction value corresponding to the color of the blue pigment added to the dielectric layer of the plasma display panel is output by correcting the color coordinates corresponding to the characteristics of the plasma display panel and the gamma value to adjust the color of white. To correct by dropping Plasma display device, characterized in that. The method of claim 4, wherein The plasma display panel, An upper substrate and a lower substrate disposed substantially parallel at any interval; A plurality of sustain discharge electrodes disposed on a lower surface of the upper substrate; An upper dielectric layer formed on the entire lower surface of the upper substrate while covering the sustain discharge electrodes and to which the blue pigment is added; A protective film coated on the upper dielectric layer; A plurality of address electrodes formed on the lower substrate opposite the upper substrate; A lower dielectric layer formed on the entire upper surface of the lower substrate while covering the address electrodes and to which the blue pigment is added; A plurality of partition walls provided with the lower dielectric layer and having a predetermined height to form a discharge space; And Phosphor layer formed in the discharge space Plasma display device comprising a. The method of claim 4, wherein The plasma display panel driver, A gamma correction unit which receives an external input image signal and performs a gamma correction by dropping a weight of a gamma correction value corresponding to the color of the blue pigment added to the dielectric layer of the plasma display panel; A sustain / scan pulse driver for generating a subfield array according to the image signal output from the gamma correction unit, and generating and applying a control signal based on the generated subfield array to the plasma display panel; An error diffusion unit for diffusing a display error with respect to neighboring pixels to correct a gray level lost when the image signal output from the gamma correction unit is converted into a gray level that can be expressed by the plasma display panel; And The memory controller which receives the gray scale data output from the error diffusion unit, generates subfield data corresponding to the subfield array generated by the sustain / scan pulse driver, and applies the grayfield data to the plasma display panel. Plasma display device comprising a. The method of claim 6, The plasma display panel driver, Detects the load ratio of the image signal output from the gamma correction unit, calculates the APC (Automatic Power Control) level according to the detected load ratio, calculates the number of sustain discharge pulses corresponding to the calculated APC level, and maintains and scans the pulse. APC unit to output to the driver Plasma display device further comprising. delete The method according to any one of claims 4 to 7, And the dielectric layer comprises 0.25% to 2.0% of the blue pigment.

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