JP2002170524A - Fluorescent lamp and color liquid crystal display using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-mercury fluorescent lamp having the same color reproduction area as that of a color CRT, suitable for achieving a color liquid crystal display with high color temperature, and also provide a color liquid crystal display using the above fluorescent lamp. SOLUTION: Y2 O3:Eu, Zn2 SiO4:Mn, BaMg2 Al16O27:Eu is used as a fluorescent material, each mixing ratio of which is [49.8-61.6]:[17.5-22.8]:[20.0-27.4] gravity, respectively. This fluorescent material is emitted by vacuum ultraviolet light radiated from excited noble gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device, and more particularly to a fluorescent lamp suitable as a light source for a backlight of a color liquid crystal display device, and a color liquid crystal display device using the same.

[0002]

2. Description of the Related Art Color liquid crystal display devices are expected to generate great demand in personal computers, especially notebook personal computers, and are expected to be developed into desktop personal computers, monitors, and televisions. So far, most of the color liquid crystal display devices are transmissive color liquid crystal display devices. However, in the transmissive color liquid crystal display device, light from a backlight light source provided behind the color liquid crystal display device is used. Light is transmitted through the color filter pixels of the three primary colors so that a color image is displayed.

[0003] As a backlight light source, a fluorescent lamp is often used, but since mercury is sealed in this fluorescent lamp, disposal of the mercury is a problem from the viewpoint of environmental conservation. Fluorescent lamp manufacturers are considering collecting and recycling fluorescent lamps. However, regarding the disposal of mercury, a drastic solution has been demanded, not by methods such as collection and recycling.

The demand for display colors of a color liquid crystal display device used in the notebook personal computer, portable terminal, and the like is that from the viewpoint of power consumption, saturation, that is, lightness (transmittance) even if the color reproduction range is somewhat inferior. ) Is high, and a color filter having a high lightness (transmittance) corresponding to this demand has been demanded.

On the other hand, among the display colors of a color liquid crystal display device used for a monitor, a television, etc., a demand for a color gamut is as follows. For example, a color reproduction area on a chromaticity diagram is set to be the same as a color CRT. In addition, among the display colors of the color liquid crystal display devices used for monitors, televisions, and the like, white, that is, as a demand for color temperature, a high color temperature, for example,
9000K or more.

[0006]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned demands for a drastic solution to the disposal of mercury and the demands for the display colors of color liquid crystal display devices used in monitors, televisions and the like. This is a fluorescent lamp in which mercury is not sealed, and on a CIE chromaticity diagram, NTSC (Na
Tional Television System
Provided is a fluorescent lamp as a light source for a backlight, which is suitable for realizing a color liquid crystal display device having a color gamut equivalent to the color gamut of the standard value of the (Committee) system and having a high color temperature. Is the subject.
Another object of the present invention is to provide a color liquid crystal display device having the above color reproduction range and a high color temperature, using the fluorescent lamp.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a fluorescent lamp in which an electrode is sealed in a sealed body provided with a phosphor coating on an inner surface and a rare gas is filled therein, wherein Y2O3 is used as a phosphor constituting the phosphor coating. : Eu, Zn2SiO4: Mn,
BaMg2Al16O27: Eu was used, and the mixing ratio was [49.8-61.6]: [17.5-22.
8]: A fluorescent lamp having a weight of [20.0 to 27.4], wherein the phosphor emits light by vacuum ultraviolet rays emitted by the excited rare gas.

The present invention is also the fluorescent lamp according to the above invention, wherein the rare gas is any one of xenon, krypton, argon, neon, helium, or a mixture thereof.

The present invention also relates to the fluorescent lamp according to the present invention, wherein the emission spectrum of the phosphor is Y.
This fluorescent lamp is characterized in that the emission intensity at the peak wavelength of 2O3: Eu is higher than the emission intensity at the peak wavelength of another phosphor.

[0010] The present invention also provides the fluorescent lamp according to the above invention, wherein the color temperature is in the range of 6500K to 15000K.

Further, the present invention is a color liquid crystal display device using the fluorescent lamp according to the present invention.

[0012]

Embodiments of the present invention will be described below in detail. As a backlight light source provided behind a color liquid crystal display device, for example, a fluorescent lamp such as a three-wavelength fluorescent lamp is often used. This fluorescent lamp stimulates a phosphor with ultraviolet rays having a wavelength of 253.5 nm obtained by discharging mercury sealed in an enclosure to emit visible light.

On the other hand, in the fluorescent lamp according to the present invention, no mercury is sealed in the envelope, but a rare gas is sealed, and the fluorescent lamp is illuminated by vacuum ultraviolet rays having a wavelength of about 200 nm or less obtained by discharging the excited rare gas. It stimulates the body to emit visible light. Thus, in the fluorescent lamp according to the present invention, mercury is not used,
This is a fluorescent lamp that has drastically solved the disposal of mercury.

A color CRT for a color television receiver is also provided.
Is within the triangle surrounded by three chromaticity points on the chromaticity diagram of the three primary colors emitted by the red (R), green (G), and blue (B) phosphors. . For example, NTS
C (National Television Sys)
The area of a triangle on the chromaticity diagram surrounded by three chromaticity points according to the standard value of the (temCommittee) method is the color reproduction range in the NTSC method.

The standard values of the NTSC red (R), green (G), and blue (B) three primary colors in the chromaticity diagram of the CIE 1931 standard display system are shown below. Rx = 0.67, Ry = 0.33 Gx = 0.21, Gy = 0.71 Bx = 0.14, By = 0.08

In the following, there is shown a formula for calculating a color reproduction range (an area (S) of a triangle formed by three chromaticity points) in the NTSC standard value on the chromaticity diagram of the CIE1931 standard display system. . S = | Ry (Gx-Bx) + Gy (Bx-Rx) + By (Rx-Gx) | /2=0.1582

On the other hand, a display color in a transmission type color liquid crystal display device is determined by a spectral distribution of a light source used as a backlight light source, a spectral transmittance of three primary colors of a color filter, and chromaticity coordinates obtained from a color matching function. It is represented. Therefore, the range of colors that can be reproduced by the transmission type color liquid crystal display device is red (R) of the color liquid crystal display device,
It is inside a triangle surrounded by three chromaticity points on the chromaticity diagram of the three primary colors, green (G) and blue (B).

The present invention is based on the CIE chromaticity diagram.
T's NTSC (National Television)
The present invention provides a fluorescent lamp suitable for realizing a color liquid crystal display device having a high color temperature and a color reproduction range equivalent to the color reproduction range of the standard value of the System Committee (System Committee) system. % Of the color gamut of a certain color filter (i) with respect to the color gamut 100% of the standard value of the NTSC system when a fluorescent lamp according to
TSC ratio) is determined by the following equation.

(Si / S) × 100 where: Si: CI of a certain color filter (i)
The area of the triangle on the E chromaticity diagram S: 0.1582 Further, Si is obtained by the following equation. Si = | Ryi (Gxi-Bxi) + Gyi
(Bxi-Rxi) + Byi (Rxi-Gxi
) | / 2 where Rxi, Ryi, Gxi, Gyi, B
xi and Byi are chromaticity coordinates of a certain color filter (i)

[0020] In the fluorescent lamp according to the present invention, the phosphor constituting the phosphor coating provided on the inner surface of the envelope includes:
Eu activated Y2O3 for red, Mn activated Zn2 for green
SiO4, Eu activated BaMg2 Al16O2 for blue
7, and the mixing ratio of each phosphor was [49.8 to 61.
6]: [17.5 to 22.8]: [20.0 to 27.
4] It is heavy. The light obtained by stimulating the phosphor with vacuum ultraviolet light is suitable for realizing a color liquid crystal display device having the above color reproduction range and a high color temperature.

[0021]

EXAMPLES <Example 1> (Preparation of Fluorescent Lamp) The red phosphor was 59.7 in weight ratio, the green phosphor was 20.0 in weight ratio, and the blue phosphor was 20 in weight ratio.
3 and mixed with a mixer. The mixed phosphor was put into butyl acetate in which nitrocellulose was dissolved and mixed well to form a suspension. This was applied to the inner wall of a glass tube having a diameter of 32 mm, and the phosphor was dried.
And a lower sealing step was performed, and then a rare gas was sealed in an exhaust step. Furthermore, the surface of the lead wire of the electrode was plated with solder to produce a 40 watt straight tube fluorescent lamp. The color temperature of the obtained fluorescent lamp was 7,500K. FIG. 1 shows the emission spectrum (spectral distribution) of this fluorescent lamp.

(Preparation of photosensitive coloring composition) Acrylic resin (20 parts of methacrylic acid, 30 parts of butyl acrylate, and 50 parts of butyl methacrylate) were dissolved in 300 parts of ethyl cellosolve, and 0.75 parts of azobisisobutylnitrile was added under a nitrogen atmosphere. Was added and the acrylic resin obtained by the reaction at 70 ° C. for 5 hours was diluted with ethyl cellosolve so that the resin concentration became 20%. Pigment 1 for 50 g of this diluted resin
3 g, dispersant 0.6 g, cyclohexanone 3 as a solvent
6.4 g was added, and the mixture was sufficiently kneaded with three rolls to produce a red colored resin. Similarly, pigment 1 is added to 50 g of the diluted resin.
1 g, dispersant 1.0 g, cyclohexanone 3 as solvent
8.0 g was added, and the mixture was sufficiently kneaded with three rolls to prepare a green colored resin. Then, 9.5 g of a pigment, 1.0 g of a dispersant, and 39.5 g of cyclohexanone were added to 50 g of the diluted resin, and the mixture was sufficiently kneaded with a three-roll mill to prepare a blue colored resin.

The pigments and dispersants are shown below. -[Red] (1) Pigment Rubin TR (CI Pigment Red 2 manufactured by Ciba-Geigy)
64) 13 g. (2) Dispersant Compound having the following structure

[0024]

Embedded image

[For green] (1) Pigment (CI Pigment Green 7 manufactured by Toyo Ink) 6.5
g of LY2311 (CI Pigment Yellow 13 manufactured by Toyo Ink). (2) Dispersant The following copper phthalocyanine derivative CuPC [SO2N (C18H37) 2] 2

[For blue] (1) Pigment Lionol Blue ES (TOYO INK CI Pigment Blue 15: 6) 10.0 g and Lionogen Violet HR (Toyo Ink CI Pigment Violet 23) A mixture with 0.5 g. (2) Dispersant The following copper phthalocyanine derivative

[0027]

Embedded image

For 50 g of each colored resin, 4 g of dipentaerythritol acrylate and 2-methyl-1- (4-
0.8 g of (methylthio) phenyl) -2-morpholinopropan-1-one, methoxystyryltriazine 0.1 g.
2 g, 3 g of the previously synthesized diluting resin, and 41 g of propylene glycol dimethyl acetate were further added and stirred well to obtain a photosensitive coloring composition of each color.

(Preparation of Color Filter) First, a red photosensitive coloring composition was spin-coated on a substrate on which a black matrix was formed and dried. After prebaking at 70 ° C. for 20 minutes, exposure was performed at 400 mJ / cm 2 using a mask having the same pixel size as one pixel of the liquid crystal display element. It was developed with an aqueous solution of 2.5% sodium carbonate, washed with water, further washed with water, dried, and then dried at 230 ° C. for 30 minutes to solidify the pattern. The film thickness after baking was 2.4 μm. Next, the green photosensitive coloring composition was spin-coated and dried. Thereafter, a green pattern having a thickness of 2.4 μm was obtained by the same process as for red. Further, a blue photosensitive coloring composition was spin-coated and dried. Thereafter, a blue pattern having a film thickness of 2.4 μm was obtained by the same process as the previous color.

(Measurement of color gamut and color temperature) The chromaticity coordinates of each color using the fluorescent lamp produced as described above are x = 0.6700 for red, y = 0.3245, and x = 0.2 for green.
104, y = 0.7100, blue is x = 0.411, y
= 0.0800, NTSC ratio was 99.96%.

Using this color filter, 140 nm of ITO was formed on the color filter and dried at 220 ° C. for 1 hour, and then an alignment film was applied to 50 nm and dried. A color liquid crystal panel was obtained by partially laminating a TFT substrate that had been prepared in advance, injecting liquid crystal from the remaining portion, and finally laminating injection. A backlight system incorporating the fluorescent lamp produced as described above was mounted from the back to complete a color liquid crystal display.

[0032]

Since the present invention is a fluorescent lamp that does not use mercury, it is a fluorescent lamp that has drastically solved the disposal of mercury. In addition, Y2O3: Eu,
Zn2SiO4: Mn, BaMg2 Al16O2
7: Eu, and the mixing ratio thereof was [49.8-61.
6]: [17.5 to 22.8]: [20.0 to 27.
4] Since it is a fluorescent lamp that is heavy and emits fluorescent light by vacuum ultraviolet rays emitted by the excited rare gas, it has a color reproduction range equivalent to the color reproduction range of the NTSC standard of a color CRT, and The fluorescent lamp is suitable as a backlight light source for realizing a color liquid crystal display device having a high color temperature.

By using the fluorescent lamp, a color liquid crystal display device having a color reproduction range equivalent to the color reproduction range of the NTSC standard of a color CRT and having a high color temperature can be obtained.

[Brief description of the drawings]

FIG. 1 shows an emission spectrum (spectral distribution) of a fluorescent lamp according to the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/13357 G02F 1/13357 G09F 9/00 334 G09F 9/00 334 336 336F H01J 61/16 H01J 61 / 16 NF term (reference) 2H091 FA43Z FD24 LA15 4H001 CA07 XA08 XA12 XA13 XA14 XA30 XA39 XA56 YA25 YA63 5C015 PP01 PP02 PP03 PP04 PP05 5C043 AA01 AA20 BB04 CC16 CD01 DD28 EB04 EC06 EC20 5G435 A12

Claims (5)

[Claims] 1. A fluorescent lamp in which an electrode is sealed in a sealed body provided with a phosphor coating on an inner surface and a rare gas is sealed, wherein Y2O3: Eu, Z is used as a phosphor constituting the phosphor coating.
n2SiO4: Mn, BaMg2Al16O27: Eu
And the mixing ratio is [49.8-61.6]:
[17.5 to 22.8]: A fluorescent lamp having a weight of [20.0 to 27.4], wherein the phosphor emits light by vacuum ultraviolet rays emitted by the excited rare gas. 2. The fluorescent lamp according to claim 1, wherein said rare gas is any one of xenon, krypton, argon, neon, and helium, or a mixture thereof. 3. An emission spectrum of the phosphor, wherein Y
3. The fluorescent lamp according to claim 1, wherein the emission intensity of the peak wavelength of 2O3: Eu is higher than the emission intensity of the peak wavelength of another phosphor. 4. The fluorescent lamp according to claim 1, wherein the color temperature is from 6500 K to 15000.
A fluorescent lamp characterized by being in the range of K. 5. A color liquid crystal display device using the fluorescent lamp according to any one of claims 1 to 4.