JP2003157017A - Front filter for plasma display - Google Patents

Abstract

(57) [Problem] To improve light place contrast under a fluorescent lamp without impairing light emission from a plasma display. SOLUTION: By providing an absorption band at around 490 nm, only light of a fluorescent lamp is selectively dropped, and light from a plasma display is effectively transmitted.
The spectral characteristics of the transmittance of the wavelength selective filter in the wavelength range of 380 to 780 nm are 4 to 380 nm.
The transmittance at 490 nm is above the straight line connecting the transmittance of 36 nm to the straight line connecting the transmittance of 436 nm to 547 nm, and 612n
It is configured to be on the upper side with respect to a straight line connecting the transmittance from m to 780 nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a large screen, thin type,
The present invention relates to a front filter of a plasma display known as a lightweight display device.

[0002]

2. Description of the Related Art Not only in a plasma display but also in a display, a front filter having a certain transmittance is indispensable in order to improve the contrast in a bright place.

This principle is as shown in FIG. For example, if there is a front filter 31 having a transmittance of 50%, the light 33 (intensity D) from the display 32 is:
50% of the light 34 passes through the front filter 31. Further, assuming that the external light 35 (intensity R) is totally reflected on the tube surface of the display device, the light returning again is the front filter 31.
The light passes through the light 36 to be reflected, and then reflected again to the front filter 31.
After passing through from the back side, it becomes light 37 and appears on the front side. as a result,
The intensity of the reflected light 37 is 25% at the original 50% × 50%.

Under bright lighting in a general home, the quality of black in a display is more controlled by the light reflected by a fluorescent lamp or the like and entering the eyes than the intensity of black emitted by the display. Works well. Therefore, the above 50
% Just by covering the front surface of the tube surface with the front surface filter, the contrast in the bright place is doubled as follows. Contrast without front filter D / R Contrast with front filter 0.5D / 0.25R = 2D
/ R In addition, in the case of the plasma display, neon is used as the gas to be enclosed, so that the orange emission peculiar to neon is strongly emitted in addition to the phosphor emission of RGB. Therefore, 585 nm of neon orange is selected selectively for the wavelength.
If the light emission in the vicinity is suppressed, the color purity of RGB light emission intended by the plasma display, especially the color purity of R is improved.

FIG. 10 shows the transmittance characteristics of a conventional front filter showing such an improving effect. As in the transmittance curve 41, for example, the transmittance is set to about 48% only in the vicinity of 585 nm, and the other region is set to about 56% over a wide range.
A filter is designed that can reduce the white brightness of a plasma display to about 55% after transmission.

Since such a filter selectively lowers the transmittance in a relatively narrow range, it can reduce the transmittance in a wide range even for a light source having a continuous spectral characteristic such as sunlight. The deterioration of the color of the reflected light of the filter is suppressed, and a relatively neutral shade is obtained. That is,
By adopting such a wavelength selective filter,
It is possible to increase the contrast in a bright place, to make the black color look relatively uncomfortable, and to improve the color purity of the emission color from the plasma display.

[0007]

However, in such a plasma display, the absorption band near 585 nm is not sufficient for obtaining bright place contrast under a fluorescent lamp. Further, there is a problem that the improvement of the color purity of green and blue is insufficient.

The present invention has been made in view of the above problems, and an object of the present invention is to improve a bright contrast under a fluorescent lamp without impairing light emission from a plasma display.

[0009]

In order to solve the above-mentioned problems, the front filter for plasma display of the present invention comprises:
A wavelength selective filter having an absorption band near 490 nm and a transmittance at 490 nm lower than that of white light of a plasma display is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION That is, the invention according to claim 1 of the present invention has an absorption band near 490 nm, and
A front filter for a plasma display, comprising a wavelength selective filter whose transmittance in nm is lower than that of white light of the plasma display.

Further, the invention according to claim 2 of the present invention is the transmittance at each peak of red (hereinafter referred to as R), green (hereinafter referred to as G), and blue (hereinafter referred to as B) of the spectral characteristics of the three-wavelength fluorescent tube. Is within ± 4% with respect to the average value of the transmittance at the above three wavelengths, the wavelength for R among the three wavelengths is 612 nm, the wavelength for G is 547 nm, and the wavelength for B is 436 nm. It is equipped with.

The invention according to claim 3 of the present invention is
The spectral characteristic of the transmittance of the wavelength selective filter in the wavelength range of 380 to 780 nm, which is generally called visible light, is above the straight line connecting the transmittances of 380 nm to 436 nm, and the transmittance of 436 nm to 547 nm. It is characterized in that the transmittance at 490 nm is on the lower side with respect to the straight line connecting the lines and the line is on the upper side with respect to the straight line connecting the transmittances from 612 nm to 780 nm.

Further, the invention according to claim 4 of the present invention is a plasma display panel in which a pair of substrates are opposed to each other so that a discharge space is formed between the substrates and an electrode group is arranged on the substrates, and the plasma display panel. A chassis member arranged on the back side of the display panel, and a display drive circuit block arranged on the chassis member for applying a signal to the plasma display panel to perform display, and on the front side of the plasma display panel. , 49
A plasma display having a front filter having an absorption band near 0 nm and a wavelength selective filter having a transmittance at 490 nm lower than the transmittance of white light of a plasma display panel. .

A plasma display and its front filter according to an embodiment of the present invention will be described below with reference to FIG.
8 will be described with reference to FIG. 8, but the embodiment of the present invention is not limited to this.

First, the structure of the plasma display panel in the plasma display device will be described with reference to FIG. As shown in FIG. 1, a plurality of stripe-shaped display electrodes 2 forming pairs of scan electrodes and sustain electrodes are formed on a transparent front substrate 1 such as a glass substrate and cover the electrode group. Thus, the dielectric layer 3 is formed, and the protective film 4 is formed on the dielectric layer 3.

A plurality of columns covered with an overcoat layer 6 are formed on the rear substrate 5 facing the front substrate 1 so as to intersect the display electrodes 2 of scan electrodes and sustain electrodes. Stripe-shaped address electrodes 7 are formed. A plurality of partition walls 8 are arranged on the overcoat layer 6 between the address electrodes 7 in parallel with the address electrodes 7, and a phosphor layer 9 is provided on a side surface between the partition walls 8 and a surface of the overcoat layer 6. There is.

The substrate 1 and the substrate 5 are a display electrode 2 and an address electrode 7 which are scan electrodes and sustain electrodes.
Are arranged so as to be substantially orthogonal to each other, and are opposed to each other with a minute discharge space interposed therebetween, and the periphery is sealed, and one kind of helium, neon, argon, and xenon or a mixed gas is discharged into the discharge space. It is enclosed as a gas. Further, the discharge space is partitioned into a plurality of partitions by partition walls 8 to provide a plurality of discharge cells at which the intersections of the display electrodes 2 and the address electrodes 7 are located, and each of the discharge cells has red, green, and blue. The phosphor layers 9 are sequentially arranged for each color so that

FIG. 2 shows the electrode arrangement of this plasma display panel. As shown in FIG. 2, the scan electrodes, the sustain electrodes and the address electrodes have a matrix structure of M rows × N columns and are arranged in the row direction. M rows of scan electrodes SCN1 to SCNM and sustain electrodes SUS1 to
Address electrodes D1 of N columns in which the SUSMs are arranged in the column direction
~ DN are arranged.

In the plasma display panel having such an electrode structure, by applying a write pulse between the address electrode and the scan electrode, an address discharge is generated between the address electrode and the scan electrode, and after selecting a discharge cell. , Between the scan electrode and the sustain electrode,
By applying a periodic sustain pulse that is alternately inverted, a sustain discharge is generated between the scan electrode and the sustain electrode, and a predetermined display is performed.

FIG. 3 shows an example of the overall structure of a plasma display incorporating the panel having the structure described above. In the figure, a housing for accommodating the panel 10 is composed of a front frame 11 and a metal back cover 12. The front frame 11 is provided with a wavelength selective filter in the opening and also protects the panel 10. A front filter 13 made of glass or the like is arranged. Also, this front filter 1
3 is also provided with an unnecessary radiation suppression filter such as silver vapor deposition that suppresses unnecessary radiation of electromagnetic waves. Further, the back cover 12 is provided with a plurality of ventilation holes 12a for radiating the heat generated in the panel 10 and the like to the outside.

The panel 10 is held by adhering a heat conductive sheet 15 to the front surface of a chassis member 14 made of aluminum or the like, and a signal is applied to the panel 10 on the rear surface side of the chassis member 14. A plurality of circuit blocks 16 are attached as display drive circuit blocks that perform display. The heat conductive sheet 15 is
The heat generated in the panel 10 is efficiently transmitted to the chassis member 14 to radiate heat. The circuit block 16 includes an electric circuit for driving the display of the panel 10 and controlling the display. The electrode block extending to the edge of the panel 10 extends beyond the four edges of the chassis member 14. It is electrically connected by a plurality of extending flexible wiring boards (not shown).

On the rear surface of the chassis member 14, a boss portion 14a for attaching the circuit block 16 and fixing the back cover 12 is provided by projecting integrally by die casting or the like. The chassis member 14
May be constructed by fixing a fixing pin to an aluminum flat plate.

Next, the front filter for plasma display according to the present invention will be described with reference to FIGS.
The present invention is characterized by including a wavelength selective filter having an absorption band near 490 nm and having a transmittance at 490 nm lower than the transmittance of white light of a plasma display.

FIG. 5 shows a general fluorescent lamp (three-wavelength fluorescent tube).
Is a spectral characteristic of. As you can see from this, 43
There is a B peak near 6 nm, a G peak near 547 nm, and an R peak near 612 nm. On the other hand, FIGS. 6 to 8 show the spectral characteristics of each of the three primary colors of RGB of the plasma display. 585 nm for both RGB
A small peak is seen in the vicinity. This is the peak due to neon emission.

Generally, the wavelength of B having a high purity and a large contribution to luminance is around 450 to 460 nm, the wavelength of G with a high purity is around 520 to 530 nm, and the wavelength of R with a high purity is around 610 to 620. Is. Further, looking at FIG. 5, there is a broad peak near 490 nm.

That is, as shown in FIG. 4, the wavelength selective filter provided in the plasma display is
When the absorption band near 90 nm is provided, reflection from the fluorescent lamp is suppressed, light from the plasma display can be effectively transmitted, and the bright place contrast is improved. In addition, since the light of portions other than B and G is dropped, the color purity of B and G is improved. In this case, in order to obtain this effect as much as possible, it is sufficient that the transmittance at 490 nm is lower than the transmittance of white light from the plasma display.

Next, when the light of the fluorescent lamp is reflected by the plasma display and the color tones that come into the eyes is made as white as possible without any discomfort, the most light emission becomes the most dominant for each color. It suffices to keep the transmittance at the three peaks of high intensity shown in FIG. 5 at 436 nm, 547 nm and 612 nm substantially constant.

Generally, it is said that the value which is visually perceived as having the same white color tone is such that the distance between chromaticity coordinates in the uv chromaticity coordinate system is within 0.005. To achieve this goal, the emission intensity of the RGB primary colors is calculated. Here, the conversion formula between the uv chromaticity coordinate and the xy chromaticity coordinate is (1)
And the equation (2), the xy coordinate values of the RGB primary colors and the luminance Y
(Value for R, value for xr, yr, Yr, G, x
The chromaticity coordinates and luminance of the combined color output when combining the values for g, yg, Yg, B, xb, yb, Yb) are given by equations (3) to (7), respectively. In addition,
xk, yk, and Yk are chromaticity coordinates and luminance for the colors that make up R and G, and the chromaticity coordinate obtained by combining the three colors is (x, y), and the luminance is Y. u = 4x / (-2x + 12y + 3) (1) v = 9y / (-2x + 12y + 3) (2) xk = (xr.Yr / yr + xg.Yg / yg) / (Yr / yr + Yg / yg) (3) yk = (Yr + Yg ) / (Yr / yr + Yg / yg) (4) x = (xb · Yb / yb + xk · Yk / yk) / (Yb / yb + Yk / yk) (5) y = (Yb + Yk) / (Yb / yb + Yk / yk) ( 6) Y = Yr + Yg + Yb (7) In order to keep the amount of change in chromaticity at the uv coordinate within 0.005 in diameter, the luminance of RGB may change by using equations (1) to (6). Calculate back. Then R
If any one of GB moves, it is within the above 0.005 circle even if it moves ± 4%, and it can be visually recognized as the same white. That is, 436n
m, 547 nm, 612 nm transmittance T436, T
547 and T612, three average values Ta = (T4
36 + T547 + T612) / 3, the transmittance of each of them should be within plus or minus 4%. Note that all of RGB move randomly, and under the worst condition, it becomes ± 2%.

That is, in the present invention, the RG of the spectral characteristic of the three-wavelength fluorescent tube is used as the characteristic of the wavelength selective filter.
The transmittance at each peak of B falls within ± 4% of the average value of the transmittance at the above three wavelengths, and the wavelength of R among the three wavelengths is 612 nm,
Wavelength for G is 547 nm, wavelength for B is 436
nm.

FIG. 4 shows an example of the transmittance characteristics of the wavelength selection filter used in the front filter for plasma display according to the present invention. FIG. 4 shows that the brightness ratio of the white light emission brightness of the plasma display with and without the filter (that is, the brightness transmittance of the plasma display for white light) is 55%.
It is an example of the spectral characteristics 21a and 21b of the transmittance in the case of. The above-mentioned luminance transmittance Tp may be expressed as Tp = Lf / Lp, where Lp is the luminance of the panel without a filter and Lf is the luminance measured through the filter when white is displayed on the plasma display panel. it can.

Here, the wavelength 38 which is generally called visible light is used.
Consider the region from 0 nm to 780 nm divided into four regions. The separated point is point A at 380 nm.
1, 436 nm point B1, 547 nm point C1, 612
A point D1 of nm and a point E1 of 780 nm.

First, in the region between 436 nm and 547 nm, a straight line 2 connecting the transmittances at 436 nm and 547 nm is provided in order to provide an absorption band at 490 nm and reduce the transmittance.
The transmittance value at 490 nm of the spectral characteristics for 3 is on the lower side. At this time, even if the transmittance near 436 nm or 547 nm is partially above the straight line 23, 490 nm
If there is a minimum value in the vicinity and it is smaller than the straight line 23, there is no particular problem. Further, the ultraviolet region and the infrared region cause malfunctions, and are therefore generally cut. In addition, between 547 nm and 612 nm, 585
A neon cut filter may be inserted to provide an absorption band near nm.

When the neon cut is put, the transmittance curve 21a is below the straight line 24 connecting the transmittances at 547 nm and 612 nm, and when there is no neon cut, the transmittance curve 21b is It is on the upper side of the straight line 24.

That is, in the present invention, the transmittance characteristics of the wavelength selection filter are shown by the transmittance curves 21a and 21 with respect to the straight line 22 connecting the transmittances of 380 nm and 436 nm.
b is on the upper side and the straight line 23 connecting the transmittances of 436 nm and 547 nm, the transmittance curves 21a and 21b are on the lower side, and the straight line 25 connecting the transmittances of 612 nm and 780 nm is the transmittance The curves 21a and 21b have a characteristic of being on the upper side. The positions of the transmittance curves 21a and 21b near 585 nm are 547 nm and 612 nm.
It depends on the presence or absence of a neon cut with respect to the straight line 24 connecting the transmittances.

[0035]

As is apparent from the above description, according to the present invention, the emission of light from a fluorescent lamp in the vicinity of 490 nm is selectively suppressed, so that the light emission from the plasma display is not impaired, and the bright light under the illumination of the fluorescent display is maintained. The contrast can be improved and the blue and green color purity of the plasma display can be improved.

Further, by defining the transmittance at three peaks of the spectral characteristic of the three-wavelength fluorescent tube to be substantially constant, neon that suppresses the absorption band near 490 nm and the neon orange emission peculiar to the plasma display. Even when the cut filter is strongly inserted, the black color due to the reflection of external light can be made white without any discomfort, and the three-primary-color light emission of the plasma display, especially the red color purity can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a panel of a plasma display according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an electrode array of the plasma display panel.

FIG. 3 is an exploded perspective view showing an arrangement structure inside the plasma display.

FIG. 4 is a characteristic diagram showing an example of a wavelength selection filter used as a front filter of the plasma display.

FIG. 5 is a characteristic diagram showing an example of spectral characteristics of a three-wavelength fluorescent tube.

FIG. 6 is a characteristic diagram showing an example of a red monochromatic spectral characteristic of a plasma display.

FIG. 7 is a characteristic diagram showing an example of monochromatic green spectral characteristics of a plasma display.

FIG. 8 is a characteristic diagram showing an example of monochromatic blue spectral characteristics of a plasma display.

FIG. 9 is a schematic diagram for explaining the role of a front filter.

FIG. 10 is a characteristic diagram showing an example of a conventional front filter transmittance.

[Explanation of symbols]

10 panels 13 Front filter 14 Chassis member 16 circuit blocks

Claims (6)

[Claims] 1. An absorption band near 490 nm, and 4
A front filter for a plasma display, comprising a wavelength selective filter having a transmittance at 90 nm lower than that of white light of the plasma display. 2. The spectral characteristics of a three-wavelength fluorescent tube are red, green,
The transmittance of each of the blue peaks is within ± 4% of the average value of the transmittances of the above three wavelengths, and the wavelength of red among the three wavelengths is 612n.
The front filter for a plasma display according to claim 1, further comprising a wavelength selective filter having a wavelength of 547 nm for m and green, and a wavelength of 436 nm for blue. 3. The wavelengths 380 to 7 of the wavelength selective filter.
The spectral characteristic of the transmittance in the region of 80 nm is 380 n.
It is on the upper side with respect to the straight line connecting the transmittances from m to 436 nm, and on the lower side with respect to the straight line connecting the transmittances from 436 nm to 547 nm, and on the lower side with the transmittance from 612 nm to 780 nm. The front filter for plasma display according to claim 1, wherein the front filter is on the upper side with respect to the connected straight line. 4. A plasma display panel in which a pair of substrates are opposed to each other so that a discharge space is formed between the substrates and an electrode group is arranged on the substrates, and a chassis member arranged on the back side of the plasma display panel. A display driving circuit block disposed on the chassis member and applying a signal to the plasma display panel to perform display, and having an absorption band near 490 nm and a wavelength of 490 nm on the front side of the plasma display panel. A plasma display, comprising: a front filter having a wavelength selective filter having a transmittance lower than that of white light of a plasma display panel. 5. The red, green, and spectral characteristics of a three-wavelength fluorescent tube
The transmittance of each of the blue peaks is within ± 4% of the average value of the transmittances of the above three wavelengths, and the wavelength of red among the three wavelengths is 612n.
5. The plasma display according to claim 4, further comprising a wavelength selective filter having a wavelength of 547 nm for m and green and 436 nm for blue. 6. The wavelengths 380 to 7 of the wavelength selective filter.
The spectral characteristic of the transmittance in the region of 80 nm is 380 n.
It is on the upper side with respect to the straight line connecting the transmittances from m to 436 nm, and on the lower side with respect to the straight line connecting the transmittances from 436 nm to 547 nm, and on the lower side with the transmittance from 612 nm to 780 nm. The plasma display according to claim 4, wherein the plasma display is on the upper side with respect to the connected straight line.