CA1038619A - Luminescent screen - Google Patents
Luminescent screenInfo
- Publication number
- CA1038619A CA1038619A CA194,552A CA194552A CA1038619A CA 1038619 A CA1038619 A CA 1038619A CA 194552 A CA194552 A CA 194552A CA 1038619 A CA1038619 A CA 1038619A
- Authority
- CA
- Canada
- Prior art keywords
- luminescent
- terbium
- borates
- earth metals
- borate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
- C09K11/7766—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
- C09K11/778—Borates
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- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
- Vessels And Coating Films For Discharge Lamps (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
A luminescent terbium-activated borate defined by the formula M3Ln2-xTbx(BO3)4 in which M represents at least one of the alkaline earth metals calcium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutetium, ytterbium and dysprosium and in which 0.01 ? x ? 1.50.
These luminescent borates may be used in low-pressure mercury vapour discharge lamps and in low-pressure cadmium vapour discharge lamps.
A luminescent terbium-activated borate defined by the formula M3Ln2-xTbx(BO3)4 in which M represents at least one of the alkaline earth metals calcium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutetium, ytterbium and dysprosium and in which 0.01 ? x ? 1.50.
These luminescent borates may be used in low-pressure mercury vapour discharge lamps and in low-pressure cadmium vapour discharge lamps.
Description
- ' PHN . 6798 BROUj~vdV
4 .2 .74 "Luminescent screen".
_ _ _ _ _ -The invention relates to a luminescent screen provided with a luminescent terbium-activated borate.
Furthermore the invention relates to low-pressure mercury vapour discharge lamps andlow-pressure cadmium vapour discharge lamps provided with such a luminescent screen and to the luminescent borate i$self.
The use of terbium as an activator in luminescent materials is known and, particularly when the material is intended for discharge lamps, it has greater ad-vantages. The emitted radiation of a terbium-activated material is generally concentrated for a great part in a narrow band in the spectrum at an area where the eye sensitivity curve is at a maximum so that the lumen equivalent of the radiation is high. The emission spectrum furthermore includes lines in the blue, yellow and red spcctrum so that the colour rendition of lamps comprising such luminescent material is improved.
Finally the terbium-activated materials generally have a favourable temperature dependence of the luminous flux, i.e, the luminescence is not extinguished until relatively high temperatures of the material.
Consequently these materials can be satisfactorily used in lamps in which the luminescent material must be actlve at an elevated temperature.
4 .2 .74 "Luminescent screen".
_ _ _ _ _ -The invention relates to a luminescent screen provided with a luminescent terbium-activated borate.
Furthermore the invention relates to low-pressure mercury vapour discharge lamps andlow-pressure cadmium vapour discharge lamps provided with such a luminescent screen and to the luminescent borate i$self.
The use of terbium as an activator in luminescent materials is known and, particularly when the material is intended for discharge lamps, it has greater ad-vantages. The emitted radiation of a terbium-activated material is generally concentrated for a great part in a narrow band in the spectrum at an area where the eye sensitivity curve is at a maximum so that the lumen equivalent of the radiation is high. The emission spectrum furthermore includes lines in the blue, yellow and red spcctrum so that the colour rendition of lamps comprising such luminescent material is improved.
Finally the terbium-activated materials generally have a favourable temperature dependence of the luminous flux, i.e, the luminescence is not extinguished until relatively high temperatures of the material.
Consequently these materials can be satisfactorily used in lamps in which the luminescent material must be actlve at an elevated temperature.
2-,~ :
: ~ .
~~ PI~.6798 ~.2.74 1038~19 Known terbium-activated luminescent borates are, for example, lanthanum borate (LaB03) and gadolinium borate (GdB03). Furthermore German Patent Specification 1,227,590 describes terbium-activated alkaline earth borates whose fundamental lattice lS
defined by the formula nMO.mB203, in which M represents one or more of the alkaline earth metals calcium, strontium and barium and in which n/m has a value of between 1/3 and 4. More efficient than the said alkaline earth borates are the terbium-activated alkaline earth alkali borates which are described in .
German Patent Specification 1,284,2g6 and have a fundamental lattice defined by the formula aMO.bM'20.cB203 in which ~ represents one or more f the alkaline earth metals calcium, strontium, barium and magnesium and M' represents one or more of the alkali metals lithium, potassium and sodium. The ratio a ~ b/c ~as a value of between ~ and 4 for these materials. These luminescent borates have, however, the drawback that when used in lamps they may attack the glass of the lamps. ~ome of these borates, notably the very efficient terbium-activated CaNaB03 further-more have the drawback that they are solub1e in water so that it is difficult to provide them in lamps.
The object of the invention is to provide - novel luminescent terbium-activated borates which are at least as efficient as the said borates known
: ~ .
~~ PI~.6798 ~.2.74 1038~19 Known terbium-activated luminescent borates are, for example, lanthanum borate (LaB03) and gadolinium borate (GdB03). Furthermore German Patent Specification 1,227,590 describes terbium-activated alkaline earth borates whose fundamental lattice lS
defined by the formula nMO.mB203, in which M represents one or more of the alkaline earth metals calcium, strontium and barium and in which n/m has a value of between 1/3 and 4. More efficient than the said alkaline earth borates are the terbium-activated alkaline earth alkali borates which are described in .
German Patent Specification 1,284,2g6 and have a fundamental lattice defined by the formula aMO.bM'20.cB203 in which ~ represents one or more f the alkaline earth metals calcium, strontium, barium and magnesium and M' represents one or more of the alkali metals lithium, potassium and sodium. The ratio a ~ b/c ~as a value of between ~ and 4 for these materials. These luminescent borates have, however, the drawback that when used in lamps they may attack the glass of the lamps. ~ome of these borates, notably the very efficient terbium-activated CaNaB03 further-more have the drawback that they are solub1e in water so that it is difficult to provide them in lamps.
The object of the invention is to provide - novel luminescent terbium-activated borates which are at least as efficient as the said borates known
-3-':'.
., - , ':
- PHN.6798
., - , ':
- PHN.6798
4.2.74 ~038619 from German Patent specification 1,284,296 and which do not have the dra~backs of these known - materials.
According to the invention a luminescent screen is provided with a luminescent terbium-activated borate and is characterized in that the borate is defined by the formula M3Ln2 xTbx(B03)4 in which M represents at least one of the alkaline ; earth metals calcium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutstium, ytterbium and dysprosium and in which 0.01 ~ x ~ 1.50.
A luminescent borate according to the invention can be satisfactorily excited by electrons, X-ray radiation and ultraviolet radiation, particularly by short-wave ultraviolet radiation. The spectral distribution of the radiation emitted by the borate is that of the characteristic terbium emission consisting of a very high narrow peak (half value width approximately 10 nm) at approximately 543 nm with the addition of a number of side emissions.
The fundamental lattice of the luminescent materials according to the invention (general formula M3~n2(B03)4) is known from recent publications (see for example Uch. Zap. Azerb. Univ. Ser. Kh~m. Nauk 1970, no. 4, 18-21). All compounds defined by this general formula have an isomorphic crystal structure with an orthorhombic ymmetry.
~4~
~ . :
- P~N.6798 4.2.74 The terbium concentration x in a luminescent borate according to the invention can be chosen within the above given wide limits. For values of x of less than 0.01 materials having a too low terbium emission are obtained whose quantum efficiency is too low.
The highest luminous fluxes are obtained with luminescent borates according to the invention for which the terbium content x has a value of between 0.3 and 1Ø Such materials are therefore preferred.
~ or the element denoted by Ln lanthanum is preferably chosen because very efficient luminescent materials are then obtained and because lanthanum is economically the most advantageous element from the group denoted by Ln.
The borates according to the invention may -very advantageously be used in combination with other luminescent materials as a green component in low-pressure mercury vapour discharge lamps for general illumination purposes. They have the advantage that they can easily be introduced into the lamps with the aid of the commonly used application techniques.
A further possibiiity of use of the borates according to the invention is in low-pressure mercury vapour -discharge lamps for special purposes where a narrow ~and emission in thegreen part of the spectrum is desired, for example, in xerographic photocopy equipment.
SuFh apecial lamps are o~ten urder a high load ~o that ':
: . . '' -~ ,.
~ , :
-- .
- Pl~N.6798 4.2.74 103~6~9 the luminescent screen is brought to a relatively high temperature. The luminescent borates according - to the invention have the advantage that they have an eminent temperature dependence of the luminous flux so that they can be used in such high-power lamps without any objection.
A very advantageous use of the borates according to the invention is in low-pressure cadmium vapour discharge lamps because they can eminently be excited by the radiation originating from such a dis-charge (230-330 nm). The excitation maximum of these borates is found at approximately 230 nm. Also for this use the favourable temperàture dependence of the luminous flux of the borates is a greater ad-vantage because the luminescent material in such lamps is brought to a high temperature.
The luminescent borates according to the invention are preferably manufactured by means of a solid state reaction at an elevated temperature.
The starting material is a mixture of the composite oxides or of compounds producing these oxides upon temperature increase (for example, caronates, boric acid as a source for boron trioxide etc.). This mixture is heated for a given period at a temperature of between 800C and the melting point. It is advan-tageous to perform the heat treatment in several stage~.
Firstly a preheating treatment is carried out at a _ ~.
' PHN.6798 4.2.74 relatively lo~ temperature, for example, 600-8000C
whereafter one or more heat treatments can be performed at a higher temperature, for example, 800-1200C
in a weakly reducing atmosphere.
The invention will now be described in greater detail with reference to an example and a number of measurementsO
Example.
A mixture is made of 2,215 g SrC03 2.960 g BaC03 2.085 g La203 1.346 g Tb407 2.475 g H3B03 ; -15~ This mixture is introduced into a quartz crucible and heated in air in a furnace for 1 hour at 700C. After cooling the product is pulverized and subsequently heated for 2 hours at a temperature of 1000C. The firing atmosphere at this heat treatment is weakly reducing and may be obtained for example, by passing a mixture of nitrogen with some % by volume of hydrogen into the furnace. After cooling, grinding and sieving the reac$ion product obtained is again - heated in a weakly reducing atmosphere for 2 hours at a temperature of 1150C. After cooling the product is ground and sieved and then it is ready for use.
It consists of a luminescent terbiumactivated borate defi~ed by the formula Sr1.5Ba~.5La~.28T 0.72 ( 3 4 ~ ' ' .
.
P~N.6798 4.2.74 ~038619 Analogously as described in the above-- mentioned example a large number of luminescent borates according to the invention was obtained.
It can be shown by means of X-ray diffraction analyses that these borates have an orthorhombic crystal structure.
The following Table shows the res~lts of measurements on a number of the luminescent borates obtained in this manner. In addition to the compo-sition for each example the Table states the measuring results upon excitation by ultraviolet radiation at a wavelength of 254 nm and the result upon excitation by ultraviolet radiation at a wavelength of 230 nm.
The measurements at 254 nm. excitation comprise the luminous flux L0 (in % relative to a calcium halophosphate activated by antimony and manganese and mixed with non-luminescent calcium carbonate in such quantities that the luminous flux of halophosphate has decreased by approximately 50 %), the absorption (A) of the exciting radiation in ~, and for some examples the value of the luminous flux at 300C in ~ relative to the luminous flux at room temperature (L0300). The measure-ments at 230 nm excitation state the peak height (PH) of the terbium emission band at 543 nm in %. The peak height of the emission of example 19 is fixed at 100~.
.
Furthermore the Table states the reflection (R) of the exciting radlation ln % relative to the reflection : .
, PHN.679 4.2.74 103B6~9 of calcium carbonate and the quantum efficiency (Q) at 230 nm excitation.
The borates according to examples 15 to 22 in the Table are manufactured in the manner as described in the above-mentioned example. The materials of examples 1 to 6 are obtained by heating the firing mixture for 1 hour in air at 700C, followed by a heat treatment for 2 hours in a weakly reducing atmos-phere at 1100C~ The materials of examples 7 to 14 are fired for 1 hour in air at 700C and subsequently ~ four times fired, every time for 2 hours, in a weakly reducing atmosphere at 900, 1000, 1100 and 1200C, respectively. The materials of examples 23 to 29 are manufactured in the same manner as the materials of examples 7 to 14 in which, however, one firing treatment in a weakly reducing atmosphere (namely that at 1000C) was not carried out.
The borates according to examples 1 to 6 and 23 to 29 are manufactured from firin~ mixtures comprising 5 mol % of B203 in an excess. As is known ~ a small excess of one or more of the composite ; components in the firing mixture may enhance the formation reaction.
The Table clearly shows that the luminescent borates according to the invention can yield high luminous fluxes both in low-pressure mercury vapour discharge lamps (predominantly 254 nm excitation) ; , .
:, ' ~
- PHN.6798 4.2.74 ~03~619 and in low-pressure cadmium vapour discharge lamps (inter alia 230 nm - excitation). As regards the temperature dependence of the luminous flux of these borates it can be stated that all these materials have a luminous flux which is 50 ~ of the luminous flux at room temperature, at temperatures of approximately 500C or more. In some cases this value of the luminous flux is only reached at temperatures which are considerably higher than 500C.
-TABLE-'.
-10- ~ .
.:
P~.6~98 ~ 4.2.74 10~ 9 TABLE
, .
Exampl~ Composition 254nm-exc. ; 230 nm-e~c.
_ L0 ¦A ¦LO~OOI PH R Q
1 Sr3Gd1,94Tbo~o6( 3)4 41 399o 57- 21 50 2 Sr1 5Bal 5Gd1,94Tbo,06( 3)4 67 38~ 67 22 60 3 Ba3La1.94Tbo,o6( 3)4 73 3982 64 20 60 4 Sr1 5Ba1 5La1,94Tbo.06( 3)4 86 39_ 77 19 70 Sr3La1 94Tbo.o6( 3~4 60 3199 77 23 75 6 sr3GdO 97Lao~97Tbo~o6(3)4 l~3 26 _ 60 29 60 7 Ba3Gd1 94Tbo, o6 ( 3 ) 4 66 41_ 55 24 55 8 Ba3Gd1~88Tbo~12(B 3)4 85 60~ 63 12 50 9 Ba3Gd1,76Tbo~24( 3 4 112 66 75 77 5 60 Ba3Gd1 64Tbo.36( 3~4 120 73 ~ 83 7 65 11 Srl 5Bal 5Lal~94Tbo~o6(B 3)4 63 41_- 48 22 45 12 Srl 5Ba1 sLa1.88Tb0~12( 3)4 89 48~ 65 18 60 13 Sr1 5Ba1 5Lal.76Tbo.24( 3)4 110 58 ~ 84 11 70 14 Srl 5~al 5Lal,64TbO.36( 3)4 121 64 _ 93 12 80 Ba3Gd1 64Tbo,36(B 3)4 137 72 ~ 92 9 75 16 Ba3Gd1 52Tbo~48( 3)4 146 72 87 96 8 75 17 Ba3Gd1 28Tbo.72( 3)4 157 80 90 98 6 75 18 ~a3Gd1 o4Tbo.96( 3)4 154 84 89 94 5 70 19 Sr1 5Ba1 sLa,.64Tbo~36( 3)4 133 64 _ 100 12 80 Sr1 5Ba1 sLa1~52Tbo.48( 3)4 139 65 ~ 104 9 80 21 Srl 5Bal 5Lal.28TbO.72( 3)4 148 76 ~ 102 9 80 22 Sr1 5Ba1 5La1.o4Tbo~96( 3)4 144 78 ~ 104 7 80 23 Sr3Y0 97Gdo~97Tbo~o6(3)4 42 3o ~ 65 31 7 24 Ca1 5Sr1 5Y1.94TbO.06( 3)4 51 28 ~ 71 28 70 Ca3Y1 94Tbo~o6( 3)4 58 3o 88 76 28 75 26 Ca3Y0 97Gd0~97Tbo.o6(3)4 61 3o ~ 73 31 75 27 Ca3Gdl.g4Tbo~o6( 3)4 63 26 90 66 33 70 28 Cal 5Srl 5Gdl.94Tbo.o6( 3)4 47 3o _ 59 34 65 29 Sr3Gd1 94Tbo.o6( 3)440 28 _5134 55 .
According to the invention a luminescent screen is provided with a luminescent terbium-activated borate and is characterized in that the borate is defined by the formula M3Ln2 xTbx(B03)4 in which M represents at least one of the alkaline ; earth metals calcium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutstium, ytterbium and dysprosium and in which 0.01 ~ x ~ 1.50.
A luminescent borate according to the invention can be satisfactorily excited by electrons, X-ray radiation and ultraviolet radiation, particularly by short-wave ultraviolet radiation. The spectral distribution of the radiation emitted by the borate is that of the characteristic terbium emission consisting of a very high narrow peak (half value width approximately 10 nm) at approximately 543 nm with the addition of a number of side emissions.
The fundamental lattice of the luminescent materials according to the invention (general formula M3~n2(B03)4) is known from recent publications (see for example Uch. Zap. Azerb. Univ. Ser. Kh~m. Nauk 1970, no. 4, 18-21). All compounds defined by this general formula have an isomorphic crystal structure with an orthorhombic ymmetry.
~4~
~ . :
- P~N.6798 4.2.74 The terbium concentration x in a luminescent borate according to the invention can be chosen within the above given wide limits. For values of x of less than 0.01 materials having a too low terbium emission are obtained whose quantum efficiency is too low.
The highest luminous fluxes are obtained with luminescent borates according to the invention for which the terbium content x has a value of between 0.3 and 1Ø Such materials are therefore preferred.
~ or the element denoted by Ln lanthanum is preferably chosen because very efficient luminescent materials are then obtained and because lanthanum is economically the most advantageous element from the group denoted by Ln.
The borates according to the invention may -very advantageously be used in combination with other luminescent materials as a green component in low-pressure mercury vapour discharge lamps for general illumination purposes. They have the advantage that they can easily be introduced into the lamps with the aid of the commonly used application techniques.
A further possibiiity of use of the borates according to the invention is in low-pressure mercury vapour -discharge lamps for special purposes where a narrow ~and emission in thegreen part of the spectrum is desired, for example, in xerographic photocopy equipment.
SuFh apecial lamps are o~ten urder a high load ~o that ':
: . . '' -~ ,.
~ , :
-- .
- Pl~N.6798 4.2.74 103~6~9 the luminescent screen is brought to a relatively high temperature. The luminescent borates according - to the invention have the advantage that they have an eminent temperature dependence of the luminous flux so that they can be used in such high-power lamps without any objection.
A very advantageous use of the borates according to the invention is in low-pressure cadmium vapour discharge lamps because they can eminently be excited by the radiation originating from such a dis-charge (230-330 nm). The excitation maximum of these borates is found at approximately 230 nm. Also for this use the favourable temperàture dependence of the luminous flux of the borates is a greater ad-vantage because the luminescent material in such lamps is brought to a high temperature.
The luminescent borates according to the invention are preferably manufactured by means of a solid state reaction at an elevated temperature.
The starting material is a mixture of the composite oxides or of compounds producing these oxides upon temperature increase (for example, caronates, boric acid as a source for boron trioxide etc.). This mixture is heated for a given period at a temperature of between 800C and the melting point. It is advan-tageous to perform the heat treatment in several stage~.
Firstly a preheating treatment is carried out at a _ ~.
' PHN.6798 4.2.74 relatively lo~ temperature, for example, 600-8000C
whereafter one or more heat treatments can be performed at a higher temperature, for example, 800-1200C
in a weakly reducing atmosphere.
The invention will now be described in greater detail with reference to an example and a number of measurementsO
Example.
A mixture is made of 2,215 g SrC03 2.960 g BaC03 2.085 g La203 1.346 g Tb407 2.475 g H3B03 ; -15~ This mixture is introduced into a quartz crucible and heated in air in a furnace for 1 hour at 700C. After cooling the product is pulverized and subsequently heated for 2 hours at a temperature of 1000C. The firing atmosphere at this heat treatment is weakly reducing and may be obtained for example, by passing a mixture of nitrogen with some % by volume of hydrogen into the furnace. After cooling, grinding and sieving the reac$ion product obtained is again - heated in a weakly reducing atmosphere for 2 hours at a temperature of 1150C. After cooling the product is ground and sieved and then it is ready for use.
It consists of a luminescent terbiumactivated borate defi~ed by the formula Sr1.5Ba~.5La~.28T 0.72 ( 3 4 ~ ' ' .
.
P~N.6798 4.2.74 ~038619 Analogously as described in the above-- mentioned example a large number of luminescent borates according to the invention was obtained.
It can be shown by means of X-ray diffraction analyses that these borates have an orthorhombic crystal structure.
The following Table shows the res~lts of measurements on a number of the luminescent borates obtained in this manner. In addition to the compo-sition for each example the Table states the measuring results upon excitation by ultraviolet radiation at a wavelength of 254 nm and the result upon excitation by ultraviolet radiation at a wavelength of 230 nm.
The measurements at 254 nm. excitation comprise the luminous flux L0 (in % relative to a calcium halophosphate activated by antimony and manganese and mixed with non-luminescent calcium carbonate in such quantities that the luminous flux of halophosphate has decreased by approximately 50 %), the absorption (A) of the exciting radiation in ~, and for some examples the value of the luminous flux at 300C in ~ relative to the luminous flux at room temperature (L0300). The measure-ments at 230 nm excitation state the peak height (PH) of the terbium emission band at 543 nm in %. The peak height of the emission of example 19 is fixed at 100~.
.
Furthermore the Table states the reflection (R) of the exciting radlation ln % relative to the reflection : .
, PHN.679 4.2.74 103B6~9 of calcium carbonate and the quantum efficiency (Q) at 230 nm excitation.
The borates according to examples 15 to 22 in the Table are manufactured in the manner as described in the above-mentioned example. The materials of examples 1 to 6 are obtained by heating the firing mixture for 1 hour in air at 700C, followed by a heat treatment for 2 hours in a weakly reducing atmos-phere at 1100C~ The materials of examples 7 to 14 are fired for 1 hour in air at 700C and subsequently ~ four times fired, every time for 2 hours, in a weakly reducing atmosphere at 900, 1000, 1100 and 1200C, respectively. The materials of examples 23 to 29 are manufactured in the same manner as the materials of examples 7 to 14 in which, however, one firing treatment in a weakly reducing atmosphere (namely that at 1000C) was not carried out.
The borates according to examples 1 to 6 and 23 to 29 are manufactured from firin~ mixtures comprising 5 mol % of B203 in an excess. As is known ~ a small excess of one or more of the composite ; components in the firing mixture may enhance the formation reaction.
The Table clearly shows that the luminescent borates according to the invention can yield high luminous fluxes both in low-pressure mercury vapour discharge lamps (predominantly 254 nm excitation) ; , .
:, ' ~
- PHN.6798 4.2.74 ~03~619 and in low-pressure cadmium vapour discharge lamps (inter alia 230 nm - excitation). As regards the temperature dependence of the luminous flux of these borates it can be stated that all these materials have a luminous flux which is 50 ~ of the luminous flux at room temperature, at temperatures of approximately 500C or more. In some cases this value of the luminous flux is only reached at temperatures which are considerably higher than 500C.
-TABLE-'.
-10- ~ .
.:
P~.6~98 ~ 4.2.74 10~ 9 TABLE
, .
Exampl~ Composition 254nm-exc. ; 230 nm-e~c.
_ L0 ¦A ¦LO~OOI PH R Q
1 Sr3Gd1,94Tbo~o6( 3)4 41 399o 57- 21 50 2 Sr1 5Bal 5Gd1,94Tbo,06( 3)4 67 38~ 67 22 60 3 Ba3La1.94Tbo,o6( 3)4 73 3982 64 20 60 4 Sr1 5Ba1 5La1,94Tbo.06( 3)4 86 39_ 77 19 70 Sr3La1 94Tbo.o6( 3~4 60 3199 77 23 75 6 sr3GdO 97Lao~97Tbo~o6(3)4 l~3 26 _ 60 29 60 7 Ba3Gd1 94Tbo, o6 ( 3 ) 4 66 41_ 55 24 55 8 Ba3Gd1~88Tbo~12(B 3)4 85 60~ 63 12 50 9 Ba3Gd1,76Tbo~24( 3 4 112 66 75 77 5 60 Ba3Gd1 64Tbo.36( 3~4 120 73 ~ 83 7 65 11 Srl 5Bal 5Lal~94Tbo~o6(B 3)4 63 41_- 48 22 45 12 Srl 5Ba1 sLa1.88Tb0~12( 3)4 89 48~ 65 18 60 13 Sr1 5Ba1 5Lal.76Tbo.24( 3)4 110 58 ~ 84 11 70 14 Srl 5~al 5Lal,64TbO.36( 3)4 121 64 _ 93 12 80 Ba3Gd1 64Tbo,36(B 3)4 137 72 ~ 92 9 75 16 Ba3Gd1 52Tbo~48( 3)4 146 72 87 96 8 75 17 Ba3Gd1 28Tbo.72( 3)4 157 80 90 98 6 75 18 ~a3Gd1 o4Tbo.96( 3)4 154 84 89 94 5 70 19 Sr1 5Ba1 sLa,.64Tbo~36( 3)4 133 64 _ 100 12 80 Sr1 5Ba1 sLa1~52Tbo.48( 3)4 139 65 ~ 104 9 80 21 Srl 5Bal 5Lal.28TbO.72( 3)4 148 76 ~ 102 9 80 22 Sr1 5Ba1 5La1.o4Tbo~96( 3)4 144 78 ~ 104 7 80 23 Sr3Y0 97Gdo~97Tbo~o6(3)4 42 3o ~ 65 31 7 24 Ca1 5Sr1 5Y1.94TbO.06( 3)4 51 28 ~ 71 28 70 Ca3Y1 94Tbo~o6( 3)4 58 3o 88 76 28 75 26 Ca3Y0 97Gd0~97Tbo.o6(3)4 61 3o ~ 73 31 75 27 Ca3Gdl.g4Tbo~o6( 3)4 63 26 90 66 33 70 28 Cal 5Srl 5Gdl.94Tbo.o6( 3)4 47 3o _ 59 34 65 29 Sr3Gd1 94Tbo.o6( 3)440 28 _5134 55 .
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A luminescent screen provided with a luminescent terbium-activated borate, characterized in that the borate is defined by the formula M3Ln2-xTbx (BO3)4 in which M represents at least one of the alkaline earth metals calcium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutetium, ytterbium and dysprosium, and in which 0.01 ? x ? 1.5.
2. A luminescent screen according to claim 1, wherein 0.3?x?1Ø
3. A luminescent screen according to claim 1 or 2, wherein the element denoted by Ln is lanthanum.
4. A luminescent terbium-activated borate defined by the formula M3Ln2-x Tbx(BO3)4 in which M represents at least one of the alkaline earth metals cal-cium, strontium and barium and Ln represents at least one of the rare earth metals yttrium, lanthanum, gadolinium, lutetium, ytterbium and dysprosium and in which 0.01? x ?1.5.
5. A luminescent terbium-activated borate according to claim 4, wherein 0.3? x?1Ø
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7303538A NL7303538A (en) | 1973-03-14 | 1973-03-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038619A true CA1038619A (en) | 1978-09-19 |
Family
ID=19818432
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA194,552A Expired CA1038619A (en) | 1973-03-14 | 1974-03-11 | Luminescent screen |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS568879B2 (en) |
| BE (1) | BE812206A (en) |
| CA (1) | CA1038619A (en) |
| DE (1) | DE2410134C3 (en) |
| FR (1) | FR2221811B1 (en) |
| GB (1) | GB1453991A (en) |
| NL (1) | NL7303538A (en) |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52121978A (en) * | 1976-04-06 | 1977-10-13 | Iwasaki Electric Co Ltd | Fluorescent high-pressure mercury lamp |
| NL182488C (en) * | 1978-04-20 | 1988-03-16 | Philips Nv | LUMINESCENT LEAD-ACTIVATED NATURAL POTASSIUM BORATE; LUMINESCENT SCREEN; LOW-PRESSURE MERCURY DISCHARGE LAMP. |
| US4202794A (en) * | 1978-10-25 | 1980-05-13 | Westinghouse Electric Corp. | Calcium yttrium borate phosphor composition |
| NL7905680A (en) * | 1979-07-23 | 1981-01-27 | Philips Nv | LUMINESCENT SCREEN. |
| FR2485507A1 (en) * | 1980-06-27 | 1981-12-31 | Rhone Poulenc Ind | NEW LUMINESCENT LUMINESCENT SUBSTANCES BASED ON DOUBLE BORATE OF MAGNESIUM AND RARE EARTHS FOR SCREENS OR TUBES |
| JPS57115484A (en) * | 1981-01-09 | 1982-07-17 | Hitachi Ltd | Fluorescent substance and its preparation |
| JPS57136873U (en) * | 1981-02-18 | 1982-08-26 | ||
| JPS57139686U (en) * | 1981-02-25 | 1982-09-01 | ||
| JPS581788U (en) * | 1981-06-26 | 1983-01-07 | 松下電器産業株式会社 | vane pump |
| JPS581787U (en) * | 1981-06-26 | 1983-01-07 | 松下電器産業株式会社 | Closed vane pump |
| JPS58128489A (en) * | 1982-01-25 | 1983-08-01 | Matsushita Electric Ind Co Ltd | Vane pump for refrigerant |
| FR2597851B1 (en) * | 1986-04-29 | 1990-10-26 | Centre Nat Rech Scient | NOVEL MIXED BORATES BASED ON RARE EARTHS, THEIR PREPARATION AND THEIR APPLICATION AS LUMINOPHORES |
| US4926091A (en) * | 1988-09-07 | 1990-05-15 | U.S. Philips Corporation | Luminescent terbium-activated borate, luminescent screen provided with such a borate and low-pressure mercury vapor discharge lamp provided with such a screen |
| US6805813B1 (en) * | 2003-05-09 | 2004-10-19 | Osram Sylvania Inc. | High brightness green-emitting phosphor |
| US7122128B2 (en) * | 2004-04-29 | 2006-10-17 | General Electric Company | Phosphors containing borate of terbium, alkaline-earth, and Group-3 metals, and light sources incorporating the same |
| TWI362413B (en) | 2008-02-25 | 2012-04-21 | Ind Tech Res Inst | Borate phosphor and white light illumination device utilizing the same |
| CN102134489A (en) * | 2010-01-22 | 2011-07-27 | 海洋王照明科技股份有限公司 | Borate luminescent material and preparation method thereof |
| CN102140347B (en) * | 2010-01-28 | 2014-05-07 | 海洋王照明科技股份有限公司 | Borofluoride white light emitting material and preparation method thereof |
| CN110725003A (en) * | 2019-11-28 | 2020-01-24 | 中国工程物理研究院化工材料研究所 | Ytterbium-doped strontium gadolinium lanthanum borate laser crystal and preparation method and application thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1440480A (en) * | 1964-07-16 | 1966-05-27 | Philips Nv | luminescent screen |
-
1973
- 1973-03-14 NL NL7303538A patent/NL7303538A/xx active Search and Examination
-
1974
- 1974-03-02 DE DE19742410134 patent/DE2410134C3/en not_active Expired
- 1974-03-07 GB GB1026974A patent/GB1453991A/en not_active Expired
- 1974-03-11 CA CA194,552A patent/CA1038619A/en not_active Expired
- 1974-03-11 JP JP2729074A patent/JPS568879B2/ja not_active Expired
- 1974-03-12 BE BE141930A patent/BE812206A/en not_active IP Right Cessation
- 1974-03-14 FR FR7408660A patent/FR2221811B1/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2410134A1 (en) | 1974-09-19 |
| GB1453991A (en) | 1976-10-27 |
| FR2221811A1 (en) | 1974-10-11 |
| DE2410134C3 (en) | 1982-04-22 |
| FR2221811B1 (en) | 1977-10-07 |
| JPS49122490A (en) | 1974-11-22 |
| NL7303538A (en) | 1974-09-17 |
| BE812206A (en) | 1974-09-12 |
| JPS568879B2 (en) | 1981-02-26 |
| DE2410134B2 (en) | 1981-07-30 |
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