EP0871203A2 - Edelgas-Entladungslampe - Google Patents

Edelgas-Entladungslampe Download PDF

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Publication number
EP0871203A2
EP0871203A2 EP98106513A EP98106513A EP0871203A2 EP 0871203 A2 EP0871203 A2 EP 0871203A2 EP 98106513 A EP98106513 A EP 98106513A EP 98106513 A EP98106513 A EP 98106513A EP 0871203 A2 EP0871203 A2 EP 0871203A2
Authority
EP
European Patent Office
Prior art keywords
noble gas
gas discharge
discharge lamp
outer enclosure
lamp according
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.)
Withdrawn
Application number
EP98106513A
Other languages
English (en)
French (fr)
Other versions
EP0871203A3 (de
Inventor
Satoshi c/o NEC Home Electronics Ltd. Tamura
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NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Publication of EP0871203A2 publication Critical patent/EP0871203A2/de
Publication of EP0871203A3 publication Critical patent/EP0871203A3/de
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
    • H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
    • H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field
    • H01J65/046—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field the field being produced by using capacitive means around the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H01J61/0672—Main electrodes for low-pressure discharge lamps characterised by the construction of the electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/12—Selection of substances for gas fillings; Specified operating pressure or temperature
    • H01J61/16—Selection of substances for gas fillings; Specified operating pressure or temperature having helium, argon, neon, krypton, or xenon as the principle constituent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
    • H01J61/76—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only
    • H01J61/78—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only with cold cathode; with cathode heated only by discharge, e.g. high-tension lamp for advertising
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/24—Manufacture or joining of vessels, leading-in conductors or bases
    • H01J9/245—Manufacture or joining of vessels, leading-in conductors or bases specially adapted for gas discharge tubes or lamps
    • H01J9/247—Manufacture or joining of vessels, leading-in conductors or bases specially adapted for gas discharge tubes or lamps specially adapted for gas-discharge lamps

Definitions

  • the present invention relates to a noble gas discharge lamp. More particularly, the present invention relates to a noble gas discharge lamp comprising a light emitting layer comprising an aperture inside a glass bulb, and a pair of outer electrodes in the shape of a belt outside the glass bulb, in which the outer electrodes are improved in their structure so as to produce a stable travel of electric discharge.
  • reference number 1 indicates a hermetic outer enclosure in the shape of a straight tube, and is comprised of a glass bulb, for example.
  • a light emitting layer 2 is formed which is comprised of one or more kinds of fluorescent substances such as fluorescent rare earth substances and fluorescent halorine acid salt substances.
  • an aperture 2a having a certain opening angle is formed to extend over the full length of the light emitting layer 2.
  • the outer enclosure 1 is sealed by adhering glass plates in the shape of a disc to the ends of the glass bulb.
  • the outer enclosure 1 can also be sealed by tapering and cutting the ends of the glass bulb, while heating.
  • the internal part of the outer enclosure 1 is filled with one kind of noble gas such as xenon (Xe), krypton (Kr), neon (Ne), helium (He), and the like, or a mixture thereof in which a metallic vapor such as mercury is not contained.
  • noble gas such as xenon (Xe), krypton (Kr), neon (Ne), helium (He), and the like, or a mixture thereof in which a metallic vapor such as mercury is not contained.
  • noble gas comprising xenon as a main component is preferable.
  • the outer laminate 3 is rolled closely into the outside of the outer enclosure 1.
  • the outer laminate 3 may be composed of a light transmitting sheet 4, a pair of outer electrodes 5 and 6, terminals 51 and 61, and an adhesive layer 9.
  • the light transmitting sheet 4 has a length equal to a length of the outer enclosure 1, and a thickness in a range of 20 to 100 microns.
  • This light transmitting sheet 4 have electrical insulating properties, and may be suitably comprised of polyethylene terephtalate (PET), however, polyester resin can be also used.
  • PET polyethylene terephtalate
  • polyester resin can be also used.
  • the above-mentioned pair of outer electrodes 5 and 6 are comprised of a metallic member having a light insulating property, the appearance thereof is tape shape, and it is adhered to one surface of the light transmitting sheet 4 so as to separate one outer electrode 5 from the other outer electrode 6 at a certain interval.
  • the terminals 51 and 61 are connected electrically to the ends of the outer electrodes 5 and 6. They are arranged at the edge of the light transmitting sheet 4 so that the ends thereof project from the edge of the light transmitting sheet 4.
  • the thickness of the terminals 51 and 61 is preferably in a range of 0.1 to 0.5 mm.
  • the outer electrodes 5 and 6 and the terminals 51 and 61 are comprised of metals having differing corrosion potentials; for instance, aluminum foil in the shape of a tape is suitable for the outer electrodes 5 and 6. In addition to aluminum, nickel and other metals which have excellent electroconductivity and light insulating properties can comprise the outer electrodes 5 and 6. Regarding the terminals 51 and 61, copper in the shape of a strip is suitable. However, in addition to copper, metals such as silver, stainless steel, Cu-Ni alloy, and the like can comprise the terminals 51 and 61.
  • the width (w) of the outer electrodes 5 and 6, and the width (d) of the terminals 51 and 61 preferably satisfy the formula: 0.1 w ⁇ d ⁇ 0.5 w.
  • the adhesive layer 9 has sticky properties and/or adhesive properties, and is adhered to one surface of the light transmitting sheet 4.
  • the adhesive layer 9 is suitably comprised of a silicon adhesive agent; however, acryl resin adhesive agents and the like can also be used.
  • a plating layer (not shown in the Figures) is formed on the terminals 51 and 61.
  • the plating layer is comprised of metals which are different from metals comprising the outer electrodes 5 and 6 and the terminals 51 and 61, and of which the corrosion potential difference is between the corrosion potential differences of the metals comprising the outer electrodes 5 and 6 and the terminals 51 and 61.
  • the outer electrodes 5 and 6 are comprised of aluminum foil and the terminals 51 and 61 are comprised of copper; nickel and lead-tin solder can be listed as metals suitable for comprising the plating layer.
  • the plating layer can be formed preferably by electroplating or electroless plating; however, the plating layer can also be formed by an immersion or a flame spray.
  • the thickness of the plating layer is preferably in a range of 5 to 30 microns, more preferably in a range of 10 to 20 microns. However, a plating layer having a thickness outside the range can also be used.
  • the aforementioned outer laminate 3 is formed onto the outside of the outer enclosure 1 so that the outer electrodes 5 and 6 are positioned between the outer enclosure 1 and the light transmitting sheet 4.
  • One edge 4a of the light transmitting sheet 4 is laminated and adhered to the other edge 4b at the following second opening portion 8.
  • a first opening portion 7 is formed by the side portions of the outer electrodes 5 and 6, and the second opening portion 8 is formed by the other side portions of outer electrodes 5 and 6.
  • the light from the light emitting layer 2 is emitted mainly from the first opening portion 7 via the aperture 2a.
  • the noble gas discharge lamp comprising the above-mentioned components can be produced by the following steps.
  • a water soluble fluorescent paint is made by mixing water soluble fluorescent substances having an emission spectrum in a blue range, a green range, and a red range, for example.
  • the light emitting layer 2 is formed by coating the water soluble fluorescent paint on the inside of the outer enclosure 1 comprised of a glass bulb, by drying and then firing.
  • the aperture 2a is formed by peeling off and by forcibly removing a part of the light emitting layer 2, while maintaining a certain opening angle, by using a scraper (not shown in the Figures).
  • the obtained outer enclosure 1 is sealed and is filled with a certain amount of noble gas such as xenon and the like.
  • the outer laminate 3 is formed by positioning one pair of the outer electrodes 5 and 6 on the light transmitting sheet 4 so as to be disposed with a certain space therebetween, so that the terminals 51 and 61 project out from the edge of the outer electrodes 5 and 6, and by forming the adhesive layer 9 onto the upper surfaces of the light transmitting sheet 4 and the outer electrodes 5 and 6.
  • the unfolding of outer laminate 3 obtained by the above-mentioned steps is positioned on the stage 10.
  • the outer enclosure 1 is positioned on the outer laminate 3 so that the outer enclosure 1 is positioned on the edge 4a of the light transmitting sheet 4, and the longitudinal axis of the outer enclosure 1 is parallel to the longitudinal axis of the outer electrodes 5 and 6.
  • Rollers 11 and 11 are positioned so that the outer enclosure 1 is contacted with some pressure to the light transmitting sheet 4, while maintaining the above conditions.
  • the stage 10 While maintaining the above conditions, as shown in Figure 13, the stage 10 is moved in the direction M, and is then moved in the direction N. Because of these movements, the outer laminate 3 is wound around the outside of the outer enclosure 1, and one edge 4a is overlapped on the other edge 4b of the light transmitting sheet 4, as shown in Figure 10. Then, the noble gas discharge lamp is produced by adhering the edges 4a and 4b of the light transmitting sheet 4 with the adhesive layer 9.
  • the noble gas discharge lamp having the above-mentioned components, light emitted from the light emitting layer 2 is concentrated in the outer enclosure 1, and is emitted from the outside of the noble gas discharge lamp via the first opening portion 7 and the aperture 2a. Therefore, when the noble gas discharge lamp is used in an office automation device such as an illumination device, the intensity of illumination on a document being scanned can be increased. As a result, accurate scanning of documents can be improved.
  • the noble gas discharge lamp will have the following effects.
  • the plating layer is formed between the outer electrodes 5 and 6 and the terminals 51 and 61; therefore, even if the outer electrodes 5 and 6 and the terminals 51 and 61 which are comprised of metals having different corrosion potential from each other, are connected directly, generation of corrosion due to the contact of different kinds of metal can be prevented.
  • the width (w) of the outer electrodes 5 and 6 and the width (d) of the terminals 51 and 61 are set to satisfy the following formula: 0.1 w ⁇ d ⁇ 0.5 w, corrosion due to contact of different kinds of metal can be effectively prevented, in company with the existence of the plating layer. Therefore, a stable travel of electric discharge of the noble gas discharge lamp can be maintained for long periods.
  • width (d) of the terminals 51 and 61 is less than 0.1 w, contact intensity to the outer electrodes 5 and 6 of the terminals 51 and 61 is decreased.
  • width (d) of the terminals 51 and 61 is more than 0.5 w, in winding the outer laminate 3 around the outside of the outer enclosure 1, the terminals 51 and 61 could not be wound around the outside of the outer enclosure 1 more easily . This process is extremely troublesome. Therefore, it is preferable that width (w) of the outer electrodes 5 and 6 and the width (d) of the terminals 51 and 61 satisfy the above-mentioned formula.
  • the adhesive layer 9 is formed on one surface of the light transmitting sheet 4; therefore, the outer laminate 3 can be adhered closely to the outside of the outer enclosure 1 by a simple step, that is, simply by rolling the outer enclosure 1 onto the outer laminate 3.
  • the outer electrodes 5 and 6 are positioned previously so as to be disposed at a certain interval from each other on the light transmitting sheet 4; therefore, in adhering the outer laminate 3 to the outer enclosure 1, it is not necessary to adjust the positioning of the outer electrodes 5 and 6 to maintain a certain interval therebetween. Therefore, it can be anticipated that not only will the work efficiency be greatly improved, but automated production of the noble gas discharge lamp will also be possible. That is, production of the noble gas discharge lamp in large quantities may be anticipated.
  • the resulting noble gas discharge lamp is switched on to produce light by applying a high voltage of high frequency (for example, a frequency of 30 kHz and a voltage of 2500 V o-p ) to the outer electrodes 5 and 6, from an inverter circuit 12, via the terminals 51 and 61.
  • a high voltage of high frequency for example, a frequency of 30 kHz and a voltage of 2500 V o-p
  • the voltage applied to the outer electrodes 5 and 6 is approximately 2500 V o-p in a noble gas discharge lamp which is 8 mm in external diameter and 360 mm in total length.
  • this noble gas discharge lamp is different from lamps having one discharge along the longitudinal direction of the outer enclosure 1, such as a noble gas discharge lamp having a hot cathode or a cold cathode. More specifically, innumerable discharges occur between the outer electrodes 5 and 6 (discharges are generated approximately perpendicularly to the longitudinal direction of the outer enclosure 1); therefore, when such a light is turned on, light is emitted in a striped pattern in the above-mentioned noble gas discharge lamp. Electric discharges in a striped pattern cannot be confirmed under normal lighting conditions.
  • the output electric power from the inverter circuit 12 is decreased 10 %, for example, by a change of voltage from a power source, the electric discharges in a striped pattern can be confirmed. Moreover, the electric discharging positions (points) are not stable and travel in the longitudinal direction of the outer enclosure 1, without interruption. The light emitting from aperture 2a is therefore intermittent.
  • the noble gas discharge lamp in an illumination device for the office equipment such as facsimile machines, image-scanners, and the like, the light intensities at the points in the longitudinal direction of the aperture 2a change continuously. Therefore, it is possible that the scan accuracy of the illuminated document is extremely degraded, and the quality of reproduction is also degraded.
  • the present invention provides a noble gas discharge lamp comprising: an outer enclosure comprising a light emitting layer formed therein, and a pair of outer electrodes in the shape of a tape comprising a metal, which are adhered to the total length of the outside of the outer enclosure so as to be separated at a certain interval, and to form a first opening portion and a second opening portion, wherein a nonlinear edge portion is formed at one side portion of one outer electrode forming the second opening portion, and other side portion being opposite to the nonlinear edge portion, is formed linearly.
  • the nonlinear edge portion is formed at one side of one outer electrode, in which some projections project toward the opposite electrode.
  • the projections project toward the opposite electrode along the outside of the outer enclosure.
  • dents are formed among the projections of the nonlinear edge portion.
  • Figure 1 is a cross-sectional diagram showing the noble gas discharge lamp of the first embodiment of the present invention.
  • Figure 2 is a schematic view showing the outer enclosure and outer electrodes shown in Figure 1.
  • Figure 3 is a cross-sectional diagram showing the noble gas discharge lamp of the second embodiment of the present invention.
  • Figure 4 is a cross-sectional diagram showing the noble gas discharge lamp of the third embodiment of the present invention.
  • Figure 5 is a cross-sectional diagram showing the noble gas discharge lamp of the fourth embodiment of the present invention.
  • Figure 6 is a cross-sectional diagram showing the noble gas discharge lamp of the fifth embodiment of the present invention.
  • Figure 7 is a cross-sectional diagram showing the noble gas discharge lamp of the sixth embodiment of the present invention.
  • Figure 8 is a schematic view showing the outer enclosure and outer electrodes used in the seventh embodiment of the present invention.
  • Figure 9 is a schematic view showing the outer enclosure and outer electrodes used in the eighth embodiment of the present invention.
  • Figure 10 is a cross-sectional diagram showing a noble gas discharge lamp of background.
  • Figure 11 is a schematic view showing the outer laminate shown in Figure 10.
  • Figure 12 is a cross-sectional diagram taken along line X-X in Figure 11.
  • Figure 13 is a schematic view showing the process for producing the noble gas discharge lamp shown in Figure 10.
  • Figure 14 is a schematic view showing an electric circuit of a noble gas discharge lamp.
  • the nonlinear portion 5A has a periodicity. More specifically, when the outer diameter of the outer enclosure 1A is 8 mm, it is preferable that the width of the outer electrode 5 including the nonlinear portion 5A be 8 mm, the pitch thereof be 4 mm, and the height thereof (the height of the triangle) be 1.5 mm. However, the sizes of the nonlinear portion 5A can be changed, depending on the situations of using the noble gas discharge lamp or the illumination device comprised of the noble gas discharge lamp.
  • the interval between the apexes of the nonlinear portion 5A formed at the side portion 5b of the outer electrode 5 and the linear side portion 6b of the outer electrode 6 is fixed over the entire outer electrodes 5 and 6.
  • the interval between the side portions 5a and 6a forming the first opening portion 7 is fixed over the entire outer electrodes 5 and 6.
  • the outer enclosure 1A is comprised of materials having a large dielectric constant, reliable hermetic sealing properties, and light transmitting properties. However, it is preferable to use a lead glass having a large dielectric constant, for example.
  • the thickness of the outer enclosure 1A is set in a range of 0.2 to 0.7 mm, preferably in a range of 0.4 to 0.7 mm. Excellent productivity and light properties can be obtained in this range.
  • the thickness of the outer enclosure 1A is less than 0.4 mm, in particular less than 0.2 mm, the mechanical strength of the outer enclosure 1A is extremely decreased. Therefore, when the outer enclosures 1A are put into commercial production, the production rate of poor quality goods (broken glass, for example) increases. In contrast, when the thickness thereof is more than 0.7 mm, electric discharges in a striped pattern can be confirmed. Moreover, light emission from the aperture 2a becomes very intermittent. Therefore, it is preferable that the thickness of the outer enclosure 1A be in that range.
  • the internal part of the outer enclosure 1A is filled with one kind of noble gas, such as xenon (Xe), krypton (Kr), neon (Ne), helium (He), and the like, or a mixture thereof.
  • the outer enclosure 1A is filled with the noble gas under the confining pressure being in a range of 83 to 200 Torr.
  • the confining pressure When the confining pressure is in this range, starting characteristics, and light output (illumination intensity on the illuminated document) can be improved, and the occurrence of intermittent illumination can be reduced. However, when the confining pressure is less than 83 Torr, light output is not sufficiently improved. In contrast, when the confining pressure is more than 200 Torr, not only are starting characteristics inferior, but the electric discharges in a striped pattern are confirmed, and the light emitted from the aperture 2a becomes intermittent. Therefore, it is preferable that the confining pressure of the noble gas be in that range.
  • the light emitting layer 2 may include one or more kinds of fluorescent substances, depending on the manner in which the noble gas discharge lamp is to be used.
  • fluorescent borates such as fluorescent europium activated yttrium ⁇ gallium borate, and the like
  • fluorescent phosphate such as fluorescent cerium ⁇ terbium activated lanthanum phosphate (LaPO 4 : Ce,Tb), fluorescent tin activated strontium ⁇ magnesium phosphate ((SrMg) 3 (PO 4 ) 2 : Sn), fluorescent europium activated strontium boric phosphate (2SrO ⁇ (P 2 O 7 ⁇ B 2 O 3 ) : Eu), and the like
  • fluorescent cerium ⁇ terbium activated magnesium aluminate MgAl 11 O 19 : Ce, Tb
  • fluorescent cerium ⁇ terbium activated yttrium ⁇ silicate Y 2 SiO 5 : Ce, Tb
  • the light emitting layer comprises a mixture of fluorescent substances, that is, fluorescent europium activated barium ⁇ magnesium aluminate having a blue emission spectrum; fluorescent cerium ⁇ terbium activated lanthanum phosphate having a green emission spectrum; and fluorescent europium activated yttrium ⁇ gallium borate having a red emission spectrum.
  • the coated amount of the fluorescent substances is set in a range of 5 to 30 mg/cm 2 . In this range, the desired light output can be obtained. However, when the coated amount is less than 5 mg/cm 2 , the light output decreases; therefore, the illumination intensity on the illuminated document is insufficient. In contrast, when the coated amount is more than 30 mg/cm 2 , a light emitting layer 2 having uniform quality cannot be easily obtained. Therefore, the coated amount of the fluorescent substances is preferably in this range.
  • first and second opening portions 7 and 8 are formed at the interval portions between the outer electrodes 5 and 6.
  • the opening angle ⁇ 1 of the first opening portion 7 is larger than the opening angle ⁇ 2 of the second opening portion 8.
  • the opening angle ⁇ 1 of the first opening portion 7 be in the range of 60° to 90° and the opening angle ⁇ 2 of the second opening portion 8 be approximately 55°.
  • the opening angle ⁇ 1 of the first opening portion 7 can be outside the range, depending on the situation of using the noble gas discharge lamp.
  • the second opening portion 8 be narrow so as not to cause breaks in insulation; therefore, the distance between one outer electrode 5 and the other electrode 6 in the second opening portion 8 is preferably 2 mm or more.
  • the opening angle of the aperture 2a is equivalent to the first angle ⁇ 1 of the first opening portion 7, in the noble gas discharge lamp as shown in Figure 1.
  • the nonlinear portion 5A in which some projections project toward the opposite electrode is formed at the side portion 5b. More specifically, as shown in Figure 2, the nonlinear portion 5A having a series of repeated triangles is formed at the side portion 5b of the outer electrode 5. The side portion 6b of the outer electrode 6 is formed linearly.
  • the nonlinear portions 5A and 5A are formed at the side portions 5b and 6b
  • the peaks of triangles of the nonlinear portions 5A and 5A formed at the side portions 5b and 6b do not correspond to each other
  • the side portion 6b being opposite to the nonlinear portion 5A (side portion 5b), is formed linearly in this embodiment. Therefore, the positioning of the side portion 6b and nonlinear portion 5A is not restricted, because the side portion 6b is formed linearly. As a result, assembly of the noble gas discharge lamp can be improved.
  • the thickness of the outer enclosure 1A is in a range of 0.2 to 0.7 mm. Therefore, in the case that the thickness of the outer enclosure 1A is at the top of this range, when a high voltage of high frequency is applied to the outer electrodes 5 and 6, intermittent illumination easily occurs, depending on the increase of voltage to the outer enclosure 1A caused by increase of resistive components. However, even if the outer enclosure 1A is at the top of that range, intermittent illumination can be effectively prevented by the thickness of the outer enclosure 1A being in that range, in company with the existence of the nonlinear portion 5A at only side portion 5b of the outer electrode 5. In addition, light output from the first opening portion 7 via the aperture 2a can be effectively improved.
  • the nonlinear portion 5A having triangles is formed at the side portion 5b from among the side portions 5b and 6b of the outer electrodes 5 and 6 which form the second portion 8; however, the side portions 5a and 6a of the outer electrodes 5 and 6 forming the first opening portion 7 are formed linearly (this shape does not influence light emission). Therefore, even when the noble gas discharge lamp of this embodiment is used in an illumination device, illumination of a document can be approximately uniform without further measures being taken. As a result, the precision of scanning of an illuminated document can be improved by simple components.
  • the confining pressure of noble gas when the confining pressure of noble gas is high, light output increases, but the starting characteristics of the noble gas discharge lamp are degraded.
  • the confining pressure of the noble gas is set to 200 Torr, starting characteristics of a practical level can be obtained, by forming the nonlinear portion 5A in a series of repeated triangles at the side portion 5b of the outer electrode 5.
  • occurrence of intermittent illumination is effectively prevented, and the light output can be improved. Therefore, when the noble gas discharge lamp of this embodiment is used in an illumination device, stable travel of electric discharge can be obtained, and the illumination intensity on the illuminated document can be increased; therefore, the precision of scanning of an illuminated document can be improved.
  • the coated amount of the fluorescent substance is in a range of 5 to 30 mg/cm 2 ; the light output from the first opening portion 7 via the aperture 2a can be effectively improved by setting the thickness of the outer enclosure 1A to a range of 0.2 to 0.7 mm, in company with setting the confining pressure of noble gas in a range of 83 to 200 Torr.
  • the above-mentioned range of the coated amount of the fluorescent substances is 2 to 10 times as much as the amount of the fluorescent substances employed in ordinary fluorescent lamps for illumination. It is believed that the coated amount is not preferable for ordinary fluorescent lamps for illumination. However, the light output is effectively increased in the noble gas discharge lamp of the embodiment. A cause of this phenomena is not clear; however, it may be believed that this phenomena is characteristic of a noble gas discharge lamp in which innumerable discharges are formed between the outer electrodes 5 and 6 (approximately perpendicular to the longitudinal direction of the outer enclosure 1A); therefore, a striped pattern is produced.
  • the shapes of the outer electrodes 5 and 6 are formed as described above, and the coated amount of the fluorescent substances and the confining pressure of the noble gas are preferably set in those ranges, in addition to set the opening angle ⁇ 1 of the first opening portion 7 in a range of 60 to 90°, the light output emitted from the first opening portion 7 can be effectively increased.
  • the leakage of light from the second portion 8 is prevented, and light output emitted from the first opening portion 7 can be more effectively increased by setting the size of the second portion 8, that is, the interval between the peak of the nonlinear portion 5A and the side portion 6b, to approximately 2 mm.
  • FIG 3 shows the second embodiment of the present invention, and the basic components of the noble gas discharge lamp shown in Figure 3 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the opening angle ⁇ 3 of the aperture 2a is set in a range of 70° to 110° , for example; however, the angle ⁇ 3 can be changed depending on the situation or the object of using the noble gas discharge lamp.
  • the opening angle ⁇ 1 of the first opening portion 7 and the opening angle ⁇ 2 of the second opening portion 8 satisfy the relationship of ⁇ 1 > ⁇ 2 in this embodiment.
  • FIG 4 shows the third embodiment of the present invention, and the basic components of the noble gas discharge lamp shown in Figure 4 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the laminated portions 4a and 4b are melted and adhered by ultrasonic waves on the outside of the outer electrode 5; therefore, an oscillation of ultrasonic waves applying the light emitting layer 2 positioning inside of the outer electrode 1A is relieved.
  • the oscillation of ultrasonic waves applying the light emitting layer 2 positioning inside of the outer electrode 1A is relieved. As a result, a peeling off of the light emitting layer 2 from the outer enclosure 1A is substantially prevented, and light output can be improved.
  • the laminated portions 4a and 4b of the light transmitting sheet 4 are melted and adhered by ultrasonic waves; however, adhesion by an adhesive agent, by heat, or simultaneous use of both may also be employed.
  • FIG 5 shows the fourth embodiment of the present invention, and the basic components of the noble gas discharge lamp shown in Figure 5 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the electrical insulating ability between the outer electrodes 5 and 6 can be improved by forming an insulating coating having light transmitting properties, which is comprised of silicon varnish, to the outside of the outer enclosure 1A, before winding the light transmitting sheet 4A onto the outside of the outer enclosure 1A.
  • FIG 6 shows the fifth embodiment of the present invention, and the basic components of the noble gas discharge lamp shown in Figure 6 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the protective tube 13 can be forcibly contacted to the outside of the outer enclosure 1A by heating them to approximately 150 to 200°C, and the protective tube 13 is made to shrink by heat.
  • manufacturing and working efficiency in this embodiment are not as good.
  • the adhesive layer is not used, erosion does not occur due to the reaction between the material comprising the terminals 51 and 61 and the adhesive composition comprising the adhesive layer. Therefore, stable travel conditions in the noble gas discharge lamp can be maintained for long periods.
  • the joint portion is not formed in the protective tube 13; therefore, the peeling off of a laminated portion can be prevented as the peeling off of the light transmitting sheet 4 can be prevented in the third embodiment.
  • the insulating ability between the outer electrodes 5 and 6 can be improved more effectively by forming an insulating coating having light transmitting properties, which is comprised of silicon varnish, to the outside of the outer enclosure 1A, before covering the protective tube 13 over the outside of the outer enclosure 1A.
  • FIG 7 shows the sixth embodiment of the present invention, and the basic components of the noble gas discharge lamp shown in Figure 7 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the protective tube 13 can be contacted forcibly to the outside of the light transmitting sheet 4 by heating them to approximately 150°C to 200°C, and the protective tube 13 is made to shrink by heat.
  • the characteristic structure of this embodiment can be applied to the noble gas discharge lamps shown in Figures 3 to 6.
  • the electrical insulating material such as the light transmitting sheet 4 and 4A and the protective tube 13, may be omitted in the aforementioned embodiments.
  • the nonlinear portion is formed at one side portion forming the second opening 8, in which some projections project toward the opposite electrode.
  • the nonlinear portions shown in Figures 8 and 9 are preferable.
  • Figure 8 shows the seventh embodiment of the present invention, and shows unfolding of outer enclosure 1A.
  • the basic components of the noble gas discharge lamp shown in Figure 8 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • Figure 9 shows the eighth embodiment of the present invention, and shows unfolding of outer enclosure 1A.
  • the basic components of the noble gas discharge lamp shown in Figure 9 are the same as those of the noble gas discharge lamp shown in Figure 1.
  • the side portion 6b opposite to the nonlinear portion 5 C (side portion 5b), is formed linearly.
  • the remaining side portions 5a, 6a, and 6b of the outer electrodes 5 and 6 beside the side portion 5b of the outer electrode 5 are formed linearly.
  • outer electrodes 5 and 6 having the above-mentioned nonlinear portions 5B and 5C can be applied to the noble gas discharge lamps shown in Figures 1 to 7 in suitable combinations.
  • the pitch and the height of the nonlinear portions can be modified, depending on the size of the noble gas discharge lamp.
  • the fluorescent water-soluble coating solution containing fluorescent cerium ⁇ terbium activated yttrium ⁇ silicate (Y 2 SiO 5 : Ce, Tb) having an emission spectrum in yellow-green wavelengths was obtained.
  • the light emitting layer 2 was formed by coating the obtained fluorescent water-soluble coating solution on the inside of the outer enclosure 1A comprised of lead glass, which was 8 mm in external diameter, 0.5 mm in thickness, and 360 mm in length. Moreover, the coated amount of the fluorescent water-soluble coating solution was 15 mg/cm 2 .
  • the aperture 2a having 75° in the opening angle ⁇ 3 was obtained by forcibly peeling off a part of the obtained light emitting layer 2 using a scraper.
  • the outer enclosure 1A was sealed, and filled with xenon gas at a confining pressure being varied in a range of 70 to 230 Torr.
  • the noble gas discharge lamps of this Experimental Example were produced by the same steps shown in Figures 13. Moreover, a pair of the outer electrodes 5 and 6 was comprised of aluminum foil in the shape of a tape 8 mm in width. As shown in Figure 2, the nonlinear portion 5A was formed at only one side portion 5b of the outer electrode 5 forming the second opening portion 8, in which triangles 4 mm in pitch and 1.5 mm in peak height were formed. The side portion 6b being opposite to the nonlinear portion 5A (side portion 5b) is formed linearly.
  • the obtained noble gas discharge lamps were incorporated in an electric circuit as shown in Figure 14, and the output voltage (frequency fixed at 30 kHz, voltage 2500 V o-p ) of the inverter circuit 12 were gradually increased. Then, the voltages at which discharge occurred (starting voltages) were measured in which the intermittent illumination was not confirmed. The result of this measurement was shown in the following Table 1. Confining Pressure of Xenon Gas (Torr) Starting Voltages (V) 70 1750 83 2000 90 2000 100 2000 110 2250 120 2250 150 2250 200 2250 210 2500 230 2500
  • the confining pressure of xenon gas is 200 Torr or less, even when the output voltage of the inverter circuit 12 was set to 90 % of a fixed voltage (2500 V o-p ), the intermittent illumination cannot be confirmed, and stable travel of electric discharge can be obtained after the lamps are lit.
  • the starting voltage in a range of 300 to 600 V can be decreased in the noble gas discharge lamps of this Experimental Example.
  • the confining pressure is 83 Torr or greater in the conventional noble gas discharge lamp, the intermittent illumination can be confirmed.
  • the confining pressure reaches 100 Torr, the conventional noble gas discharge lamp cannot be used in practice without difficulty.
  • the lamps can be lit with a fixed voltage (2500 V o-p ); however, start-up is not assured when the input power was decreased.
  • the obtained noble gas discharge lamps were incorporated in an electric circuit as shown in Figure 14, and the output voltage (frequency fixed at 30 kHz) of the inverter circuit 12 was set to 90 % of a fixed voltage (2500 V o-p ). In these conditions, the illumination intensities on the document were measured at a point 8 mm away from the outer enclosure 1A. The results were shown in the following Table 2.
  • the obtained noble gas discharge lamps were incorporated in an electric circuit as shown in Figure 14, and the output voltage (frequency fixed at 30 kHz) of the inverter circuit 12 was set to 90 % of a fixed voltage (2500 V o-p ). In these conditions, the occurrence of intermittent illumination was evaluated at a point 8 mm away from the outer enclosure. The results were shown in the following Table 2.
  • ⁇ means that intermittent illumination did not occur, ⁇ means that some intermittent illumination did occur, but the noble gas discharge lamp can be used in practice without difficulty, and X means that intermittent illumination did occur, and the noble gas discharge lamp cannot be used in practice without difficulty.
  • the confining pressure of xenon gas is 150 Torr or less, stable travel of electric discharge without occurrence of intermittent illumination can be obtained.
  • the confining pressure of xenon gas is 200 Torr, some intermittent illuminations did occur, but the noble gas discharge lamp can be used in practice without difficulty.
  • the pressure being more than 200 Torr, specifically 210 Torr and 230 Torr, the significant intermittent illumination occurs. Therefore, it is confirmed that it is difficult to use the noble gas discharge lamps in an illumination device because the scanning precision of an illuminated document is degraded.
  • the illumination intensity on the illuminated document increases, depending on an increase of the confining pressure of xenon gas; however, a stable illumination intensity without occurrence of intermittent illumination can be obtained when the confining pressure of xenon gas is in a range of 200 Torr or less.
  • the obtained noble gas discharge lamps were incorporated in an electric circuit as shown in Figure 14, and the output voltage (frequency fixed at 30 kHz) of the inverter circuit 12 was set to 90 % of a fixed voltage (2500 V o-p ). In these conditions, the occurrence of intermittent illumination was evaluated at a point 8 mm away from the outer enclosure. The results were shown in the following Table 3.
  • ⁇ means that intermittent illumination did not occur, ⁇ means that some intermittent illumination did occur, but the noble gas discharge lamp can be used in practice, and X means that intermittent illumination did occur, and the noble gas discharge lamp cannot be used in practice without difficulty.
  • ⁇ means that damage to the outer enclosure was not observed, and the strength of the outer enclosure is sufficient; ⁇ means that some damage was observed in the outer enclosure, but the noble gas discharge lamps comprising the outer enclosures can be used in practice; and X means that serious damage to the outer enclosure was observed and the strength of the outer enclosure meant the produced lamps would be difficult to use.
  • Thickness of the outer enclosure Occurrence of intermittent illumination Strength 0.18 ⁇ X 0.2 ⁇ ⁇ 0.25 ⁇ ⁇ 0.4 ⁇ ⁇ 0.5 ⁇ ⁇ 0.6 ⁇ ⁇ 0.7 ⁇ 0.8 X ⁇
  • the thickness of the outer enclosure 1A is in a range of 0.18 to 0.6 mm, the occurrence of intermittent illumination cannot be confirmed, even when the input to the outer electrodes 5 and 6 is low.
  • the noble gas discharge lamp can be used in practice without difficulty.
  • the thickness is less than 0.4 mm, especially 0.25 mm and 0.2 mm, damage in the production was observed.
  • the thickness is 0.18 mm, damage such as cracks suddenly increases; therefore, it is confirmed that mechanical strength is low, and they are unsuitable for producing in large quantities.
  • the thickness of the outer enclosure is preferably in a range of 0.2 to 0.7 mm, more preferably in a range of 0.4 to 0.7 mm.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Plasma & Fusion (AREA)
  • Manufacturing & Machinery (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
EP98106513A 1997-04-11 1998-04-08 Edelgas-Entladungslampe Withdrawn EP0871203A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP94017/97 1997-04-11
JP9401797A JPH10289693A (ja) 1997-04-11 1997-04-11 希ガス放電灯

Publications (2)

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EP0871203A2 true EP0871203A2 (de) 1998-10-14
EP0871203A3 EP0871203A3 (de) 1999-03-17

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2843483A1 (fr) * 2002-08-06 2004-02-13 Saint Gobain Lampe plane, procede de fabrication et application
EP1536453A3 (de) * 2003-10-09 2007-08-08 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Entladungslampe mit mindestens einer aussenelektrode und Verfahren zu ihrer Herstellung
EP2034511A3 (de) * 2007-01-15 2009-07-15 Samsung Electronics Co., Ltd. Beleuchtungslichtquelle, mit der Lichtquelle ausgestattetes Abtastmodul und Bildabtastvorrichtung mit dem Abtastmodul

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EP0871205A1 (de) * 1997-04-07 1998-10-14 Nec Corporation Edelgasentladungslampe
EP0871204A1 (de) * 1997-04-07 1998-10-14 Nec Corporation Edelgasentladungslampe

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DE1539515C3 (de) * 1966-08-05 1975-12-04 Patent-Treuhand-Gesellschaft Fuer Elektrische Gluehlampen Mbh, 8000 Muenchen Niederdruck-Gasentladungslampe, insbesondere Natrium-Dampflampe, mit einem rohrförmigen Entladungsbrenner
DE4010809A1 (de) * 1989-04-11 1990-10-18 Asea Brown Boveri Hochleistungsstrahler
US5117160C1 (en) * 1989-06-23 2001-07-31 Nec Corp Rare gas discharge lamp
DE4222130C2 (de) * 1992-07-06 1995-12-14 Heraeus Noblelight Gmbh Hochleistungsstrahler
JPH06314561A (ja) * 1993-05-06 1994-11-08 Mitsubishi Electric Corp 放電ランプ
JP3170963B2 (ja) * 1993-06-25 2001-05-28 ウシオ電機株式会社 誘電体バリヤ放電ランプ

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EP0871205A1 (de) * 1997-04-07 1998-10-14 Nec Corporation Edelgasentladungslampe
EP0871204A1 (de) * 1997-04-07 1998-10-14 Nec Corporation Edelgasentladungslampe

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2843483A1 (fr) * 2002-08-06 2004-02-13 Saint Gobain Lampe plane, procede de fabrication et application
EP1536453A3 (de) * 2003-10-09 2007-08-08 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Entladungslampe mit mindestens einer aussenelektrode und Verfahren zu ihrer Herstellung
US7298071B2 (en) 2003-10-09 2007-11-20 Patent - Treuhand - Gesellschaft Fuer Elektrische Gluehlampen Mbh Discharge lamp having at least one external electrode, adhesive layer, and carrier film
EP2034511A3 (de) * 2007-01-15 2009-07-15 Samsung Electronics Co., Ltd. Beleuchtungslichtquelle, mit der Lichtquelle ausgestattetes Abtastmodul und Bildabtastvorrichtung mit dem Abtastmodul
KR101079574B1 (ko) * 2007-01-15 2011-11-03 삼성전자주식회사 조명광원 및 이를 채용한 스캐너 모듈 및 이미지스캐닝장치
US8593706B2 (en) 2007-01-15 2013-11-26 Samsung Electronics Co., Ltd. Illuminating light source, scanner module employing the same, and image scanning apparatus employing the scanner module

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EP0871203A3 (de) 1999-03-17

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