JP5370299B2 - Fluorescent lamp - Google Patents

Description

  The present invention relates to a light source lamp used for manufacturing a liquid crystal panel, and more particularly to a fluorescent lamp used in a liquid crystal panel manufacturing process in which a liquid crystal containing a photoreactive substance is enclosed.

The liquid crystal panel has a structure in which liquid crystal is sealed between two light-transmitting substrates (glass substrates), and a number of active elements (TFTs) and liquid crystal driving electrodes are formed on one glass plate, An alignment film is formed thereon. On the other glass substrate, a color filter, an alignment film, and a transparent electrode (ITO) are formed. Then, liquid crystal is sealed between the alignment films of both glass substrates, and the periphery is sealed with a sealing agent.
In the liquid crystal panel having such a structure, the alignment film is for controlling the liquid crystal alignment in which the liquid crystal is aligned by applying a voltage between the electrodes.
Conventionally, the alignment film has been controlled by rubbing, but recently, a new alignment control technique has been tried (see Patent Document 1).

It reacts with light and a liquid crystal having an orientation that is aligned by applying a voltage between a first glass substrate provided with a TFT element and a second glass substrate facing the first glass substrate. The material mixed with the monomer that causes polymerization is sealed, and the liquid crystal panel is polymerized by irradiating light while applying voltage to the liquid crystal panel, and the direction of the liquid crystal in contact with the glass substrate (that is, approximately one molecular layer of the surface layer) By fixing this, a pretilt angle is imparted to the liquid crystal molecules.
This method eliminates the need for a projection having an inclined surface, which has been necessary for providing a pre-tilt angle in the prior art, so that the manufacturing process of the liquid crystal panel can be simplified. As a result, the aperture ratio is improved. As a result, the manufacturing cost and manufacturing time of the liquid crystal panel can be reduced, and further, the power consumption of the backlight can be reduced.

With reference to FIG. 11, a liquid crystal alignment regulation technique using this polymer will be described.
In the panel 90, electrodes 92 made of ITO or the like are formed on each surface of a light-transmitting substrate 91 made of glass, and a sealant (not shown) is applied, formed, and bonded to the periphery thereof. Liquid crystal is injected between the substrates 91. This liquid crystal is obtained by adding an ultraviolet curable monomer 93 in an appropriate ratio to a negative liquid crystal having negative dielectric anisotropy.
The panel 90 is subjected to voltage application and ultraviolet irradiation to regulate the alignment of the liquid crystal.

  As shown in FIG. 11A, when no initial voltage is applied, the liquid crystal molecules 94 are vertically aligned, and the monomer 93 is also present along the liquid crystal molecules in a monomer state. Here, when a voltage is applied as shown in (b), the liquid crystal molecules 94 are tilted in the direction of the fine pattern of the pixel electrode, and the monomer 93 is similarly tilted. When ultraviolet irradiation is performed in this state as shown in (c), the monomer 93 is polymerized with an inclination. In this way, the monomer 93 is polymerized with an inclination, whereby the alignment of the liquid crystal molecules 94 is regulated.

In the liquid crystal panel manufacturing technology that performs this new alignment control, the quality of the panel in the final product is largely related to whether or not the polymerization of the monomer is completed, and in the event that an uncured monomer remains, The liquid crystal panel will burn and cause defects.
For this reason, as is known from Patent Document 1 and the like, a two-stage ultraviolet irradiation process in which ultraviolet irradiation is divided into a plurality of stages is used. Specifically, as shown in FIG. 12, in the (A) primary irradiation step, the liquid crystal layer is irradiated with ultraviolet rays while a voltage is applied to the liquid crystal layer containing the liquid crystal material and the photopolymerizable monomer, and then ( B) In the secondary irradiation step, ultraviolet rays are irradiated in a state where no voltage is applied. As a result, in the state where the molecular alignment of the liquid crystal material is inclined in the primary irradiation step, the monomer in the vicinity of the alignment film is polymerized to form a polymer layer, and in the secondary irradiation step, the inclination direction of the liquid crystal molecules is stored in the polymer. . Through such a process, the monomer remaining in the liquid crystal material is completely polymerized and the monomer disappears.

  Conventionally, in the ultraviolet irradiation step, a fluorescent lamp that emits light in the ultraviolet region near a wavelength of about 300 to 400 nm called black light is used.

JP 2008-134668 A

  The emitted light from the black light contains a relatively large amount of ultraviolet rays having a short wavelength (for example, a wavelength of less than 310 nm). However, when the liquid crystal display panel is irradiated with such ultraviolet rays having a wavelength of 310 nm or less, the liquid crystal is damaged, resulting in a new problem that the reliability of the liquid crystal display panel is lowered. In order to cut off light of an unnecessary wavelength range, a filter is simply provided. However, since a fluorescent lamp is a diffused light source, it is usually necessary to use a filter having an absorption characteristic. However, in order to reliably block light having a wavelength of 310 nm or less, part of spectral light in the vicinity of 310 nm, for example, in the vicinity of 310 to 340 nm is also absorbed. That is, light in the wavelength region that contributes to the polymerization of the monomer is inevitably absorbed. As a result, there is a problem that light in a wavelength region necessary for polymerization cannot be efficiently irradiated, the polymerization rate is lowered, the ultraviolet irradiation time is lengthened, and mass productivity is deteriorated.

  Therefore, the problem to be solved by the present invention is to form a liquid crystal layer by filling a liquid crystal composition containing a polymerizable monomer between two substrates provided with electrodes, and polymerize the monomer while applying a voltage to the substrate. By providing a light source lamp that emits ultraviolet rays that can be suitably used in the monomer polymerization step in the manufacturing process of a liquid crystal display device that defines the tilt direction of liquid crystal molecules, specifically, An object of the present invention is to provide a fluorescent lamp having a maximum energy peak at 310 to 380 nm by reducing the intensity of ultraviolet rays having a wavelength shorter than 310 nm as much as possible in the spectrum.

In order to solve the above problems, a fluorescent lamp according to the present invention has the following features.
In the fluorescent lamp used in the manufacturing process of the liquid crystal panel containing the photoreactive substance, the phosphor layer formed inside the arc tube has cerium and lanthanum activated magnesium barium aluminate represented by the following general formula: It contains a phosphor .
(Ce _0.8 , La _x ) (Mg _0.8 , Ba _0.1 ) Al ₁₁ O _{18.6 + 3x}
However, 0 <x ≦ 0.06

  According to the present invention, in the wavelength of the light emitted from the fluorescent lamp, the ultraviolet intensity at a wavelength of 310 nm or less can be reduced without impairing the light intensity between 321 to 350 nm, so that the liquid crystal is damaged by 300 nm. It is possible to reduce the intensity of short-wavelength ultraviolet rays in the vicinity, reduce the damage to the liquid crystal, and reliably perform polymerization of the monomer, and the liquid crystal panel in which the liquid crystal containing the photoreactive substance is enclosed is contained. A fluorescent lamp that can be suitably used in the manufacturing process can be provided.

It is explanatory drawing which shows the ultraviolet irradiation device carrying the fluorescent lamp concerning this invention. It is explanatory drawing of the fluorescent lamp which concerns on the 1st Embodiment of this invention. It is a figure which shows the spectrum of wavelength 250-450nm of each fluorescent lamp of 1st Embodiment, a prior art example, and a comparative example. It is a figure which shows the relationship between the relative value of the integrated intensity | strength of light, and the cerium density | concentration of the damage wavelength area | region and effective wavelength area | region of the fluorescent lamp which concerns on 1st Embodiment. It is a figure which shows the spectrum of wavelength 250-450nm of each fluorescent lamp of 2nd Embodiment, a prior art example, and a comparative example. It is a figure which shows the relationship between the relative value of the integrated intensity | strength of light, and the gadolinium density | concentration of the damage wavelength area | region and effective wavelength area | region of the fluorescent lamp which concern on 2nd Embodiment. It is a figure which shows the spectrum of wavelength 250-450nm of each fluorescent lamp of 3rd Embodiment, a prior art example, and a comparative example. It is a figure which shows the relationship between the relative value of the integrated intensity | strength of light, and the cerium density | concentration of the damage wavelength area | region and effective wavelength area | region of the fluorescent lamp which concern on 3rd Embodiment. It is a figure which shows the spectrum of wavelength 250-450nm of each fluorescent lamp of 4th Embodiment, a prior art example, and a comparative example. It is a figure which shows the relationship between the relative value of the integrated intensity | strength of light, and the lanthanum density | concentration of the damage wavelength area | region and effective wavelength area | region of the fluorescent lamp which concern on 4th Embodiment. It is a figure explaining the manufacturing process of the liquid crystal panel which enclosed the liquid crystal containing a photoreactive substance inside. It is a figure explaining the manufacturing process of the liquid crystal panel which enclosed the liquid crystal containing a photoreactive substance inside.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies an ultraviolet irradiation device and a fluorescent lamp for liquid crystal production for embodying the technical idea of the present invention, and the present invention specifies the fluorescent lamp as follows. do not do.
FIG. 1 is a schematic explanatory diagram of an ultraviolet irradiation apparatus 100 for polymerizing a monomer as a photoreactive substance in a manufacturing process of a liquid crystal panel in which a liquid crystal containing a photoreactive substance is enclosed. On the work stage S, the liquid crystal panel 30 that has been carried by an appropriate transport device such as a roller is placed directly under the light irradiation unit. For example, the liquid crystal panel 30 has a frame-like sealant 32 applied between two substrates 31 made of glass and having light transmission properties, and an unreacted photoreactive substance (monomer) inside thereof. ) Containing liquid crystal 33 is injected and configured.
Each of the substrates 31 is provided with an electrode (not shown in the figure), and each electrode is connected to a mechanism for applying a voltage. Although not shown here, the ultraviolet irradiation device of the ultraviolet irradiation device 34 having a mechanism for applying such a voltage is provided.

  A light irradiation unit 20 for irradiating ultraviolet rays is formed on the liquid crystal panel 30. The light source is a fluorescent lamp 10, and here, a plurality of lamps (five in the figure) are arranged side by side. A mirror 21 that reflects light from the lamp toward the stage is provided behind the fluorescent lamp.

FIG. 2 is an explanatory diagram of a fluorescent lamp. FIG. 5A is a perspective view, FIG. 5B is a cross-sectional view perpendicular to the tube axis of the lamp, and FIG. 5C is a cross-sectional view in the tube axis direction taken along line AA in FIG.
A fluorescent lamp 10 according to an embodiment of the present invention will be described in detail. A phosphor layer 12 formed by laminating phosphors is formed on the inner wall of a light-transmitting hermetic container 11 made of a dielectric material such as glass. A discharge medium made of a rare gas such as xenon is sealed inside the hermetic container 11, and a pair of external electrodes 13 and 14 are disposed on the outer surface of the hermetic container 11. When a high frequency high voltage is applied between the pair of external electrodes 13 and 14 via the lead wires 15 and 16, a discharge is formed through the dielectric wall formed by the hermetic vessel 11, and xenon is formed. The ultraviolet light of 172 nm which is the spectrum is emitted.
The phosphor layer 12 used in the present invention emits long-wavelength ultraviolet light having an emission peak wavelength in a wavelength region of 310 to 380 nm when irradiated with such short-wavelength ultraviolet light, for example, 172 nm ultraviolet light emitted from xenon. Has a body.

Specifically, the phosphor is a phosphor in which any one of magnesium barium aluminate, gadolinium phosphate / yttrium phosphate and magnesium aluminate / lanthanum is used as a mother crystal, and each mother crystal is activated by cerium (Ce). include. In particular, Ce can take trivalent and tetravalent valences, but in the present invention, it exists as a trivalent cation. Such phosphors may be mixed and used at an appropriate ratio, but since the number of work steps increases, it is preferable to use them alone in practice. Hereinafter, each phosphor will be described in detail based on examples.
In the following description, the manufacturing process of a liquid crystal panel in which a liquid crystal containing a photoreactive substance is sealed will be described in comparison with a so-called black light that has been conventionally used for the reaction of a photoreactive substance. Although there are various phosphors used for black light, here we will explain using a cerium-activated lanthanum phosphate, which is a general phosphor, as a comparative example. A black light using this cerium-activated lanthanum phosphate phosphor is referred to as “Conventional Example 1”.
The general formula of the cerium-activated lanthanum phosphate phosphor is as follows.
General formula of cerium-activated lanthanum phosphate phosphor: (La, Ce) PO ₄

[Embodiment 1]
In the fluorescent lamp according to the first embodiment, the phosphor layer 12 is mainly made of a cerium-activated magnesium barium aluminate (Ce—Mg—Ba—Al—O) phosphor. The phosphor layer 12 is a phosphor whose general formula is represented by the following formula (1), and in particular, has a molar ratio (x) of cerium (Ce) in the range of 0.6 to 0.8. .

Equation _{(1): Ce x (Mg} 1-y-z, Ba y-z) Al 11 O 19- (3 (1-x) + 2z) / 2

  In the above formula (1), Ce as an activating metal element ideally exists as a trivalent cation. By setting the molar ratio of cerium in the range of x = 0.6 to 0.8, the ultraviolet light in a region effective for the manufacturing process of a liquid crystal panel in which a liquid crystal containing a photoreactive substance is enclosed is increased. Can be made.

  Hereinafter, the present embodiment will be described in more detail by way of examples.

(Comparative Example 1)
A cerium-activated barium / magnesium aluminate phosphor (abbreviated as CAM phosphor) represented by the following formula (2) is generally known as a phosphor having a wavelength of 310 nm or less, particularly a wavelength of 300 nm or less, which emits less ultraviolet radiation.

Formula (2): CeMgAl ₁₁ O ₁₉
In formula (2), the number of moles of cerium (Ce) is 1.

  The emission spectrum waveform in the wavelength range of 250 to 450 nm of the fluorescent lamp using the CAM phosphor of the formula (2) is shown by the curve of Comparative Example 1 in FIG. Conventional example 1 in the figure is a cerium-activated lanthanum phosphate phosphor emission spectrum waveform. Thus, the peak value of the emission spectrum in the curve of Comparative Example 1 is in the vicinity of a wavelength of 360 to 370 nm, and in the manufacturing process of the liquid crystal panel in which the liquid crystal containing the photoreactive substance is enclosed, the reaction of the photoreactive substance is performed. It was confirmed that the intensity of the spectrum region (wavelengths 321 to 350 nm; referred to as “effective wavelength band”) used in the above is large.

However, it is considered that there is room for improvement in the intensity of the effective wavelength band, and the present inventor has determined the wavelength based on the cerium-activated magnesium barium aluminate (Ce—Mg—Ba—Al—O) phosphor. An attempt was made to increase ultraviolet light in the wavelength range of 310 to 380 nm.
In the verification, in the manufacturing process of the liquid crystal panel in which the liquid crystal containing the photoreactive substance is enclosed, the spectral range used for the reaction of the photoreactive substance, that is, the effective wavelength band (wavelengths 321 to 350 nm). And the spectral range (wavelength 300 to 310 nm; hereinafter referred to as “damage wavelength band”) that damages the liquid crystal, and the spectral range (wavelength 311 to 320 nm) between them, and the integrated light quantity of each region Was compared with that of the black light according to the prior art.

(Comparative Examples 2 and 3)
First, in the general formula of CAM phosphor (formula (1)) without changing the mixing ratio of cerium, a part of magnesium which is a divalent metal ion is replaced with barium which is also a divalent metal ion, The phosphors according to Comparative Example 2 and Comparative Example 3 were produced. Hereinafter, general formulas of the respective phosphors are shown.

Comparative Example 2 Ce (Mg _0.95 , Ba _0.05 ) Al ₁₁ O ₁₉
Comparative Example 3 Ce (Mg _0.9 , Ba _0.1 ) Al ₁₁ O ₁₉

The phosphor applied to the fluorescent lamp of Comparative Example 2 is a phosphor manufactured by substituting magnesium with the addition amount of barium being 0.05 mol and the phosphor applied to the fluorescent lamp of Comparative Example 3 being 1 mol of barium. is there. In manufacturing these phosphors, Ce, Mg, Ba, and Al were mixed at a molar ratio represented by the general formula and then fired.
Using these phosphors, fluorescent lamps according to Comparative Example 2 and Comparative Example 3 were manufactured according to the configuration shown in FIG.
The fluorescent lamp thus manufactured was turned on by applying a predetermined voltage, and the light emission intensity of the lamp was measured. As a result, no significant improvement was observed due to the addition of barium. However, the fluorescent lamp according to Comparative Example 2 had a wavelength peak value shifted to a shorter wavelength side than the fluorescent lamp according to Comparative Example 3, and the emission intensity. Was found to be slightly higher.

(Comparative Example 4)
Subsequently, among the phosphors substituted with barium, an attempt was made to change the addition amount of cerium by adopting 0.1 mol of barium. Here, the molar ratio of cerium was 0.5. The phosphor was prepared by mixing Ce, Mg, Ba, and Al at a molar ratio represented by the general formula, and then firing the mixture to produce a fluorescent lamp having the configuration shown in FIG. The fluorescent lamp was turned on and the emission spectrum was verified.
As a result, it was found that the fluorescence peak was further shifted to the short wavelength side, the emission intensity was increased, and the fluorescence peak was greatly improved.
Therefore, phosphors with different cerium (Ce) concentrations were manufactured.

(Examples 1-3)
As Examples 1 to 3, phosphors were manufactured by adjusting the values of x in the above formula (2) to 0.6, 0.7, and 0.8 in this order. In addition, the cerium density | concentration of each Example is 0.6 mol, 0.7 mol, and 0.8 mol.

  A lamp shown in FIG. 2 was constructed using the obtained phosphor, turned on by applying a predetermined voltage, and its emission spectrum was verified. As a result, the absolute value of the peak intensity increased and a good emission spectrum was obtained. In these Examples 1 to 3, the photoreactive substance was reduced while reducing the integrated intensity of the wavelength band from 300 to 310 nm to 1/10 or less as compared with the configuration of the black light used in Conventional Example 1. In the manufacturing process of the liquid crystal panel in which the contained liquid crystal is enclosed, it is possible to emit more ultraviolet wavelengths having a wavelength of 320 to 350 nm, which is particularly effective.

In FIG. 3, the emission spectrum waveform of the prior art example 1, the comparative examples 1-4, and Examples 1-3 is shown collectively. Table 1 below shows the phosphor compositions according to the conventional example, the comparative example, and the examples, and the integrated values of the spectral intensities of the respective lamps having the wavelength of 300 to 310 nm, the wavelengths of 311 to 320 nm, and the wavelengths of 321 to 350 nm. .
In Table 1, the “measured value” column on the left side is an actual measurement value of this integrated intensity of a spectrum measured by a spectroscope at a position 25 mm from the arc tube. The right side shows the integrated intensity as a relative value with the integrated value of each wavelength region in the lamp of Conventional Example 1 being 100.

  FIG. 4 shows the relative values of the integrated intensities of the comparative examples and examples in Table 1 shown above in coordinates, where the vertical axis represents the relative value and the horizontal axis represents the cerium concentration. Curve (A) shows the effective wavelength band, and curve (A) shows the damage wavelength band. As can be seen from the figure, the damage wavelength band shifts in the vicinity of 10 in relative value, but the light output in the effective wavelength band is large in the range of cerium concentration of 0.6 to 0.8 mol. However, it can be seen that the efficiency decreases when the number of moles of cerium is increased to 1 mole.

  As can be seen from the above results, all of Examples 1 to 3 can reduce the intensity of the damaged wavelength band to 10 or less with respect to Conventional Example 1, and can increase the intensity of the effective wavelength band to 80 or more. Therefore, in the above formula, it was found that when the value of x is in the range of 0.6 to 0.8, light emission in the damaged wavelength band is small and light emission in the effective wavelength band is large.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described.
The fluorescent lamp according to this embodiment uses a cerium-activated gadolinium phosphate / yttrium phosphate (Gd—Y—P—O: Ce) phosphor as the phosphor layer 12 of the fluorescent lamp shown in FIG. is there. The phosphor layer 12 is a phosphor having a general formula represented by the following formula and formula (3), and in particular, a gadolinium (Gd) molar ratio (x) in a range of 0.1 to 0.5. is there

Equation _{(3) :( Y 1-x} , Gd x) PO 4: Ce ( where, 0.1 ≦ x ≦ 0.5)

  In the above formula (3), Ce as an activating metal element ideally exists as all trivalent cations. By setting the molar ratio of gadolinium in the range of x = 0.1 to 0.5, the cerium-activated gadolinium phosphate / yttrium (Gd—Y—P—O: Ce) -based phosphor can be used as a photoreactive substance. In the manufacturing process of the liquid crystal panel in which the liquid crystal containing is contained, the ultraviolet light in an effective region can be increased.

Hereinafter, the present embodiment will be described in more detail by way of examples.
In the following description, a black light using a cerium-activated lanthanum phosphate phosphor as a lamp according to the conventional example is referred to as Conventional Example 1.

(Comparative Example 5)
As a phosphor having a wavelength of 310 nm or less, particularly a wavelength of 300 nm or less, and a small amount of ultraviolet radiation, a cerium-activated yttrium phosphate (YPO: Ce) phosphor (abbreviated as YPC phosphor) represented by the following formula (4) Are known.

Formula (4): YPO ₄ : Ce

  This formula (4) cerium-activated yttrium phosphate (Y—P—O: Ce) phosphor, in particular, has a light intensity in the effective wavelength region of less than half that of Conventional Example 1 and is inefficient. Based on this phosphor, the present inventor tried to amplify ultraviolet light in the wavelength range of 310 to 380 nm in order to improve efficiency.

(Comparative Example 6)
First, a part of yttrium (Y) of the phosphor of formula (4) was replaced with gadolinium (Gd) to produce a phosphor, and a fluorescent lamp according to Comparative Example 6 was produced.

Comparative Example 6 (Y _0.95 , Gd _0.05 ) PO ₄ : Ce

  In the phosphor according to the fluorescent lamp of Comparative Example 6, the number of moles of gadolinium is 0.05 mole and the number of moles of yttrium is 0.95 mole. In manufacturing the phosphor, Gd, Y, P, and Ce were mixed at a molar ratio represented by the general formula and fired. A fluorescent lamp according to Comparative Example 6 was manufactured using this phosphor. The fluorescent lamp thus manufactured was lit by applying a predetermined voltage to obtain an emission spectrum waveform and intensity in the wavelength range of 250 to 450 nm of the emitted light from the fluorescent lamp. The result is shown by the curve of Comparative Example 6 in FIG.

(Examples 4 to 7)
As Examples 4 to 7, phosphors were manufactured by adjusting the value of x in the above formula (3) to be 0.1, 0.2, 0.3, and 0.5. The cerium concentration is 0.05 mol for all the total values of yttrium (Y) and gadolinium (Gd) of 0.95 mol.

  The lamp shown in FIG. 2 was constructed using the obtained phosphor, and the emission spectrum was verified by applying a predetermined voltage and turning on the lamp. As a result, the absolute value of the peak intensity increased and a good emission spectrum was obtained. In these Examples 4 to 7, the photoreactive substance is reduced while reducing the integrated intensity of the wavelength band from 300 to 310 nm to 1/10 or less as compared with the configuration of the black light used in Conventional Example 1. In the manufacturing process of the liquid crystal panel in which the contained liquid crystal is enclosed, it is possible to emit more ultraviolet wavelengths having a wavelength of 320 to 350 nm, which is particularly effective.

In FIG. 5, the emission spectrum waveform of the prior art example 1, the comparative example 6, and Examples 4-7 is shown collectively. Table 2 below shows the phosphor compositions according to the conventional example, the comparative example, and the examples, and the integrated values of the spectral intensities of the respective lamps having the wavelength of 300 to 310 nm, the wavelengths of 311 to 320 nm, and the wavelengths of 321 to 350 nm. .
The left column of Table 2 shows the measured values of the integrated intensity. The right side shows the integrated intensity as a relative value when the integrated value of each wavelength region in the lamp of the conventional example 1 is 100.

  FIG. 6 shows the relative values of the integrated intensities of the comparative examples and examples in Table 1 shown above in coordinates, where the vertical axis represents the relative value and the horizontal axis represents the cerium concentration. Curve (A) shows the effective wavelength band, and curve (A) shows the damage wavelength band. As can be seen from the figure, the light output in the effective wavelength band increases as the number of moles of gadolinium increases. However, at the same time, the relative value of the damaged wavelength band also increases as the light output in the effective wavelength band increases. Therefore, the range of 0.1 to 0.5 mol is a practical range for the amount of gadolinium added. Particularly preferred is when gadolinium is 0.3 mole.

  From the above results, it was confirmed that all of Examples 4 to 7 can reduce the intensity of the damaged wavelength band with respect to Conventional Example 1 to 10 or less, and can further increase the intensity of the effective wavelength band. Therefore, in the above formula (3), it was found that when the value of x is in the range of 0.1 to 0.5, light emission in the damaged wavelength band is small and light emission in the effective wavelength band is large.

[Embodiment 3]
Next, Embodiment 3 of the present invention will be described.
The fluorescent lamp according to the present embodiment uses a cerium-activated magnesium aluminate / lanthanum (La—Mg—Al—O: Ce) phosphor as the phosphor layer 12 of the fluorescent lamp shown in FIG. is there. The phosphor layer 12 is a phosphor having a general formula represented by the following formula and formula (5), and in particular, having a molar ratio (x) of cerium (Ce) in the range of 0.07 to 0.12. is there

Formula (5): (La _1-x , Ce _x ) MgAl ₁₁ O ₁₉ (where 0.07 ≦ x ≦ 0.12)

  In the above formula (5), Ce as an activating metal element ideally exists as all trivalent cations. By setting the molar ratio of cerium in the range of x = 0.07 to 0.12, photoreactivity is achieved in a cerium-activated magnesium aluminate / lanthanum (La—Mg—Al—O: Ce) phosphor. In the manufacturing process of the liquid crystal panel in which the liquid crystal containing the substance is enclosed, the ultraviolet light in an effective region can be increased.

Hereinafter, the present embodiment will be described in more detail by way of examples.
In the following description, a black light lamp using a cerium-activated lanthanum phosphate phosphor as a lamp according to the conventional example is referred to as Conventional Example 1. The number of moles of cerium (Ce) in the cerium-activated lanthanum phosphate phosphor (general formula: LaPO ₄ : Ce) is 0.05 mol.

(Examples 8 to 11)
As Examples 8 to 11, phosphors were manufactured by adjusting the value of x in the above formula (5) to 0.07, 0.09, 0.1, and 0.12. The number of moles of cerium in each example is 0.07 mol, 0.09 mol, 0.1 mol, and 0.12 mol.

  The lamp shown in FIG. 2 was constructed using the obtained phosphor, and the emission spectrum was verified by applying a predetermined voltage and turning on the lamp. As a result, the absolute value of the peak intensity increased and a good emission spectrum was obtained. In these Examples 8 to 11, the photoreactive substance was reduced while reducing the integrated intensity of the wavelength band from 300 to 310 nm to 2/5 or less as compared with the configuration of the black light used in Conventional Example 1. In the manufacturing process of the liquid crystal panel in which the liquid crystal to be contained is enclosed, it is possible to emit a larger ultraviolet wavelength of 320 to 350 nm, which is particularly effective.

In FIG. 7, the emission spectrum waveform of the prior art example 1 and Examples 8-11 is shown collectively. Table 3 below shows the phosphor compositions according to the conventional example and the example, and the integrated values of the spectral intensities of the respective lamps having the wavelength of 300 to 310 nm, the wavelengths of 311 to 320 nm, and the wavelengths of 321 to 350 nm.
The column on the left side of Table 3 shows the measured value of the integrated intensity. The right side shows the integrated intensity as a relative value when the integrated value of each wavelength region in the lamp of the conventional example 1 is 100.

  Further, in FIG. 8, the relative value of the integrated intensity of each of the comparative examples and examples of Table 3 shown above is shown in coordinates, with the relative value on the vertical axis and the concentration of cerium on the horizontal axis. Curve (A) shows the effective wavelength band, and curve (A) shows the damage wavelength band. As can be seen from the figure, the relative value of the effective wavelength region has a peak in the vicinity of 0.1 moles of cerium, and the relative value shows a good efficiency of 80 or more. The intensity of the damaged wavelength band changes in a relative value between 20 and 40, but can be reduced to about 20 by setting the cerium concentration as high as 0.1 to 0.12.

  From the above results, it was confirmed that any of Examples 8 to 11 can reduce the intensity of the damaged wavelength band with respect to Conventional Example 1 to 40 or less, and can increase the intensity of the effective wavelength band. Therefore, in the above formula (3), it was found that when the value of x is in the range of 0.1 to 0.12, light emission in the damaged wavelength band is small and light emission in the effective wavelength band is large.

[Embodiment 4]
In the fluorescent lamp according to the fourth embodiment, the phosphor layer 12 is mainly made of cerium and lanthanum activated magnesium barium aluminate (Ce—La—Mg—Ba—Al—O) phosphor. This phosphor layer 12 is a phosphor whose general formula is represented by the following formula (6), and in particular, the molar ratio (x) of cerium (Ce) is 0.8, and the molar ratio of lanthanum (La). Is in the range where 0.06 or less (excluding 0).

Formula (6): (Ce _0.8 , La _x ) (Mg _0.8 , Ba _0.1 ) Al ₁₁ O _{18.6 + 3x}

  In the above formula (6), Ce and La, which are activating metal elements, ideally all exist as trivalent cations. By setting the molar ratio of lanthanum (La) in the range of 0 to 0.06 with respect to the molar ratio of cerium to 0.8, the liquid crystal panel containing the liquid crystal containing the photoreactive substance is enclosed. It is possible to increase ultraviolet light in a region effective for the manufacturing process.

  Hereinafter, the present embodiment will be described in more detail by way of examples.

  In the description of the present embodiment, since the mother crystal of the phosphor is the same as that of the phosphor according to the first embodiment, regarding the comparative example, the contents of Comparative Examples 1 to 4 are cited, and La The case where the concentration of is 0 is the same as that of the phosphor of Example 3 described in the first embodiment, and therefore, the content of Example 3 will be described.

(Examples 12 to 16)
As Examples 12 to 16, phosphors were manufactured by adjusting the La concentration x in the above formula (6) to 0.01, 0.02, 0.04, 0.06, and 0.10. The cerium concentration in each example is 0.8 mol.

  The lamp shown in FIG. 2 was constructed using the obtained phosphor, and the emission spectrum was verified by applying a predetermined voltage and turning on the lamp. As a result, the absolute value of the peak intensity increased and a good emission spectrum was obtained. In these Examples 12 to 16, the photoreactive substance was reduced while reducing the integrated intensity of the wavelength band from 300 to 310 nm to 1/10 or less as compared with the configuration of the black light used in Conventional Example 1. In the manufacturing process of the liquid crystal panel in which the contained liquid crystal is enclosed, it is possible to emit more ultraviolet wavelengths having a wavelength of 320 to 350 nm, which is particularly effective.

FIG. 9 collectively shows emission spectrum waveforms of Conventional Example 1, Comparative Examples 1 to 4, Examples 3 and 12 to 16. Table 4 below shows the phosphor composition according to the conventional example, the comparative example, and the example, and the integrated values of the spectral intensities of the respective lamps in the wavelength range of 300 to 310 nm, the wavelengths of 311 to 320 nm, and the wavelengths of 321 to 350 nm. .
In Table 4, the “Measured Value” column on the left side is an actual measurement value of this integral intensity of a spectrum measured by a spectroscope at a position 25 mm from the arc tube. The right side shows the integrated intensity as a relative value with the integrated value of each wavelength region in the lamp of Conventional Example 1 being 100.

  Further, in FIG. 10, the relative value of the integrated intensity of each of Example 3 and Examples 12 to 16 in Table 4 shown above is expressed in coordinates, where the vertical axis represents the relative value and the horizontal axis represents the concentration of lanthanum (La). Show. Curve (A) shows the effective wavelength band, and curve (A) shows the damage wavelength band. As can be seen from the figure, the damage wavelength band changes in the vicinity of 10 relative values, but in the range of lanthanum concentration of 0 to 0.06 mol, the integrated value of 320 to 350 nm with respect to the integrated value of 300 to 310 nm. It can be seen that the integrated intensity of 321 to 350 nm is equal to or smaller than that of Example 3, and the integrated intensity of 321 to 350 nm of the conventional example is approximately 50% or more.

  As can be seen from the above results, all of Examples 12 to 15 can reduce the intensity of the damaged wavelength band with respect to Conventional Example 1 to 10 or less, and the intensity of the effective wavelength band can be 50 or more. Therefore, in the above formula (6), when the value of x is in the range of 0 <x ≦ 0.06, light emission in the damaged wavelength band is small and light emission in the effective wavelength band can be increased.

As described above, in the manufacturing process of a liquid crystal panel in which a liquid crystal containing a photoreactive substance is enclosed, any one of magnesium barium aluminate, gadolinium yttrium phosphate and magnesium lanthanum aluminate is used as a mother crystal, By constructing a fluorescent lamp using a phosphor containing a phosphor activated by Ce ^3+, it is possible to increase light in a wavelength band effective for the reaction of a photoreactive substance, and damage the liquid crystal. A fluorescent lamp that emits less light in the wavelength band can be provided.

DESCRIPTION OF SYMBOLS 100 Ultraviolet irradiation apparatus 10 Fluorescent lamp 11 Airtight container 12 Phosphor layer 13, 14 Electrode 15, 16 Lead wire 20 Light irradiation part 21 Mirror 30 Liquid crystal panel 31 Light transmissive substrate 32 Sealing agent 33 Liquid 34 containing a photoreactive substance Mechanism for applying voltage

Claims (1)

In a fluorescent lamp used in the manufacturing process of a liquid crystal panel containing a photoreactive substance,
A fluorescent lamp formed inside the arc tube includes a cerium and lanthanum activated magnesium barium aluminate phosphor, the general formula of which is represented by the following formula:
(Ce _0.8 , La _x ) (Mg _0.8 , Ba _0.1 ) Al ₁₁ O _{18.6 + 3x}
However, 0 <x ≦ 0.06

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