EP1139700A1 - Dispositif d'alimentation pour lampe a decharge - Google Patents

Dispositif d'alimentation pour lampe a decharge Download PDF

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Publication number
EP1139700A1
EP1139700A1 EP00917356A EP00917356A EP1139700A1 EP 1139700 A1 EP1139700 A1 EP 1139700A1 EP 00917356 A EP00917356 A EP 00917356A EP 00917356 A EP00917356 A EP 00917356A EP 1139700 A1 EP1139700 A1 EP 1139700A1
Authority
EP
European Patent Office
Prior art keywords
discharge
current
lamp
simulated
power
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.)
Ceased
Application number
EP00917356A
Other languages
German (de)
English (en)
Other versions
EP1139700A9 (fr
EP1139700A4 (fr
Inventor
Masashi Okamoto
Tomohiro Yamamoto
Tomoyoshi Arimoto
Yoshiteru Kondo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ushio Denki KK
Original Assignee
Ushio Denki KK
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 Ushio Denki KK filed Critical Ushio Denki KK
Publication of EP1139700A1 publication Critical patent/EP1139700A1/fr
Publication of EP1139700A4 publication Critical patent/EP1139700A4/fr
Publication of EP1139700A9 publication Critical patent/EP1139700A9/fr
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/36—Controlling
    • H05B41/38—Controlling the intensity of light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
    • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
    • H05B41/288—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices and specially adapted for lamps without preheating electrodes, e.g. for high-intensity discharge lamps, high-pressure mercury or sodium lamps or low-pressure sodium lamps
    • H05B41/292—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2928—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the lamp against abnormal operating conditions

Definitions

  • the present invention concerns a power-supply device for electric discharge lamps, for example, a power-supply device for electric discharge lamps that turns on a high-luminance high-pressure mercury vapor lamp that is used as a light source for projectors.
  • Metal halide lamps and high-pressure mercury vapor lamps have been used as a high-luminance light source.
  • the inventors conducted empirical observations under various conditions and discovered that mercury condenses on the cathode and sticks during the cooling period when a lamp is extinguished.
  • the impedance between electrodes is low during arc discharge, but since it rises during glow discharge, comparatively high operation voltage must be supplied to maintain glow discharge. However, if the voltage output from a power supply device cannot accommodate the operation voltage that rapidly rises, the lamp extinguishes at the moment of shift to glow discharge.
  • the temperature at the cathode tip would rise if glow discharge can be maintained without extinguishing, and a supply of thermions would eventually become possible, at which point the discharge would shift to arc discharge and maintenance of a steady lighting state by the discharge lamp would become possible.
  • the cathode cooling rate after the lamp extinguishes is retarded in the course of gradual lamp cooling by raising the heat capacity of the cathode or in the vicinity thereof.
  • mercury condensation commences from the cathode or the inner surface of the light bulb, and the condensation/sticking of mercury to the cathode is prevented.
  • discharge could easily shift to glow discharge so long as liquid mercury does not stick to the cathode.
  • said vertical lamp arrangement is useful in that it permits the location of devitrification, which can happen within a lamp inclusion body, to be limited to harmless sites depending on where the light is output, and installation so that the cathode is below and the anode is above is useful in that it prevents flickering, which is important depending on the conditions of lamp usage.
  • the matter resolved by the present invention involves the provision of a power-supply device for electric discharge lamps in which the extinguishing of a high pressure mercury vapor lamp with a comparatively high amount of mercury inclusion can be completely prevented when mercury is completely evaporated from the cathode.
  • the present invention uses the following means for resolving said problems.
  • the first means provides a power-supply device for electric discharge lamps that lights high pressure mercury vapor lamps in which a cathode and anode are disposed in a discharge space enclosed by an inclusion body and in which noble gas as well as 0.15 mg or more of mercury per 1 mm 3 of said discharge space are sealed, wherein a switchable connection from the connection state of a simulated arc discharge resistor virtually equal to the arc discharge resistance during arc discharge of said high-pressure mercury vapor lamp to the connection state of simulated glow discharge resistors that have virtually 1/7 of the glow discharge resistance during glow discharge of said high-pressure mercury vapor lamp is completed at the output terminal of the power-supply device for electric discharge lamps in question, said simulated arc discharge resistor is connected to the power-supply device for electric discharge lamps in question, and the simulated glow discharge current in the transient state of switch from the state of flow of simulated arc discharge current to said simulated glow discharge resistor continues to be under 30% of said simulated arc discharge current for less than 10 ⁇ s and the duration until the
  • the second means provides said power-supply device for electric discharge lamps of the first means that has a function of controlling the lamp current so that the lamp power reaches a predetermined rated power, and a function of controlling the lamp current so that the lamp current does not exceed a predetermined maximum current, wherein the function of controlling the lamp current so that the lamp current does not exceed said maximum current takes priority over said function of controlling the lamp current so that the lamp power reaches said rated power, and a control function is provided so that the duration of control so as to restore the current to at least 70% of said simulated arc discharge current is more than 50 ms upon switching to said simulated glow discharge resistor and so that this duration will tolerate said rated power to be exceeded.
  • the third means provides a power-supply device for electric discharge lamps that lights high pressure mercury vapor lamps in which a cathode and anode are disposed in a discharge space enclosed by an inclusion body and in which noble gas, 0.15 mg or more of mercury per 1 mm 3 of said discharge space and 1 x 10 -7 moles of halogen per 1 mm 3 of said discharge space are sealed in said discharge space, wherein a switchable connection from the connection state of a simulated arc discharge resistor virtually equal to the arc discharge resistance during arc discharge of said high-pressure mercury vapor lamps to the connection state of simulated glow discharge resistors that are virtually equal to the glow discharge resistance during glow discharge of said high-pressure mercury vapor lamp is completed at the output terminal of the power-supply device for electric discharge lamps in question.
  • Vag' represents the output voltage of the power-supply device for electric discharge lamps and Iag' represents the simulated glow discharge current upon switching to said simulated glow discharge resistor from the state of flow of simulated arc discharge current by connecting said simulated arc discharge resistor to the power-supply device for electric discharge lamps in question.
  • the device in which the cathode surface area is represented by Sc (mm 2 ) has the following characteristics.
  • the fourth means provides said power-supply device for electric discharge lamps of any one of said means 1 to 3 that is provided with a variable output direct current power source that inputs direct current voltage and then applies variably-controlled output voltage to said high-pressure mercury vapor lamps via a smoothing capacitor, wherein the capacitance of said smoothing capacitor is increased during transition to arc discharge following the end of glow discharge.
  • Figure 1 is a diagram that shows the periodic changes in the discharge current during transition from initial arc discharge of a high-pressure mercury vapor lamp to glow discharge and from glow discharge to arc discharge.
  • the inventors were able to create a power supply device that does not extinguish as a result of various improvements to the power supply device.
  • Figure 2 is a diagram that shows a test circuit to identify the power-supply device for electric discharge lamps used in high-pressure mercury vapor lamps that have a comparatively high amount of mercury sealed within, 0.15 mg or more per 1 mm 3 volume of the discharge space of a high-pressure mercury vapor lamp.
  • Said high-pressure mercury vapor lamps used in this implementation mode have arc discharge resistance during arc discharge of 5 ⁇ and glow discharge resistance during glow discharge of 300 ⁇ .
  • reference number 2 denotes a power-supply device for electric discharge lamps that is the object of evaluation to evaluate whether or not lamp extinguishing can be effectively prevented.
  • Reference numbers 59, 60 denote resistors of 5 ⁇ and 38 ⁇ resistance, respectively, that are connected in series to the output terminal of power-supply device 2 for electric discharge lamps.
  • Reference number 57 denotes a FET that shorts and opens resistor 60.
  • Reference number 58 denotes a gate drive circuit that switches FET 57.
  • resistor 59 is set to resistance roughly equal to the 5 ⁇ arc discharge resistance during said arc discharge so that the current flowing through resistor 59 is roughly equal to the current flowing during arc discharge when liquid mercury is present on the cathode of an actual high-pressure mercury vapor lamp
  • resistor 59 + resistor 60 are set to resistance equal to about 1/7 of the 300 ⁇ glow discharge resistance during glow discharge of said high-pressure mercury vapor lamp.
  • the resistance of resistor 59 + resistor 60 is set at about 1/7 of the glow discharge resistance in order to distinctly discriminate if the power-supply device for electric discharge lamps that is the object of evaluation has satisfied the prescribed conditions.
  • duration Tr so that it is under 100 ⁇ s before the simulated glow lamp current during rapid increase of impedance of a high-pressure mercury vapor lamp recovers to at least 70% of the simulated lamp current Iao' immediately preceding rapid increase, thermion release can be rapidly activated to complete a rapid shift to arc discharge following a shift to glow discharge.
  • a short duration Tr until the simulated glow lamp current during rapid increase of impedance of a high-pressure mercury vapor lamp recovers to at least 70% of the simulated lamp current Iao' immediately preceding rapid increase, and said issue could be attained with a reserve if it is under 80 ⁇ s, and a duration under 60 ⁇ s would be still more desirable.
  • the issue could be attained with a reserve if the extent of recovery of the lamp current were to at least 85% of the simulated lamp current Iao' immediately preceding rapid increase of the impedance of a high-pressure mercury vapor lamp.
  • the power-supply device for electric discharge lamps in the invention of this claim must be specified using a test circuit because the individual elements comprising a power-supply device for electric discharge lamps may be adjusted or modified to prevent extinguishing of a high-pressure mercury vapor lamp, and it is important whether or not the ultimately-modified power-supply device for electric discharge lamps satisfies said prescribed conditions.
  • Figure 3 is a diagram that shows simulated lamp current Ia' and simulated lamp voltage Va' in the test circuit shown in Figure 2 of a power-supply device for electric discharge lamps that satisfies prescribed conditions and does not extinguish.
  • Figure 3(a) and Figure 3(b) show the same phenomena, but the periodic scale differs.
  • Figure 4 is a diagram that shows the relation between simulated lamp current Ia' and simulated lamp voltage Va' in the test circuit shown in Figure 2 of a power-supply device for electric discharge lamps that satisfies prescribed conditions and extinguishes.
  • Figure 4(a) and Figure 4(b) show the same phenomena, but the periodic scale differs.
  • the oscilloscope was subjected to smoothing processing to facilitate contrast of Figures 3 and 4 with Figures 8 and 10 discussed below.
  • the arc discharge resistance during arc discharge of an actual high-pressure mercury vapor lamp is assumed to be Ra while the glow discharge resistance during glow discharge is assumed to be Rb. Lamp extinguishing could be effectively prevented by using a power-supply device for said high-pressure mercury vapor lamps that satisfies two conditions.
  • the first is that the duration during which the simulated glow discharge current in the transient state of switch from the state of flow of simulated lamp current Iao' to resistors (59 + 60) is under 30% of simulated lamp current Iao' is continuously less than 10 ⁇ s as a result of connecting resistor 59 to the power-supply device for electric discharge lamps that is the object of evaluation when connection to the output terminal of the power-supply device for electric discharge lamps that is the object of evaluation has been switched from connection of resistor 59 that is virtually equal to arc discharge resistance Ra to resistors (59 + 60) that have virtually 1/7 of glow discharge resistance Rb.
  • the second is that the duration would be under 100 ⁇ s before the current recovers to at least 70% of the simulated lamp current Iao'.
  • FIG. 5 is a diagram that shows one example of the structure of a power-supply device for electric discharge lamps.
  • reference number 17 denotes a DC power source that provides voltage from DC power source 17 to step-down chopper 16.
  • Step-down chopper 16 primarily comprises switch device 11, gate drive circuit 12, diode 13, inductor 14 and smoothing capacitor 15.
  • DC power source 17 is not illustrated, but a device that converts a commercial AC power source into direct current using rectifier diodes, diode bridges and smoothing capacitors, a power source module that has a function of inhibiting harmonic current or a battery can be used.
  • Reference number I denotes a high-pressure mercury vapor discharge lamp having discharge space 6 within lamp inclusion body 3 in which is sealed a comparatively large amount of mercury and in which cathode 4 and anode 5 are disposed opposing each other.
  • Reference number 18 denotes a voltage detector constructed using differential voltage resistors that detects applied voltage Va that is applied to high-pressure mercury vapor discharge lamp 1
  • reference number 19 denotes a current detector constructed using shunt resistors and CT, etc., that detects current Ia flowing to high-pressure mercury vapor discharge lamp 1.
  • Reference number 7 denotes an igniter inserted between step-down chopper 16 and high-pressure mercury vapor discharge lamp 1 to create discharge breakdown of sealed gas between cathode 4 and anode 5 when high-pressure mercury vapor discharge lamp 1 commences lighting.
  • Igniter 7 basically is constructed by transformer 8 that has a large primary-to-secondary winding ratio to generate a high-voltage pulse series of several kV to several dozen kV.
  • Reference number 9 denotes a coil that is inserted between step-down chopper 16 and discharge lamp 1.
  • Reference number 24 denotes a power-supply device control circuit that provides gate drive signal 23 to gate drive circuit 10 of igniter 7 and that inputs lamp voltage signal 20 that was detected by voltage detector 18 as well as lamp current signal 21 that was detected by current detector 19.
  • Gate drive signal 22 is supplied to gate drive circuit 12 of switch device 11 based on lamp voltage signal 20 and lamp current signal 21 so as to control switching of switch device 11.
  • the diagram shows an example in which power-supply device control circuit 24 supplies gate drive signal 23 to gate drive circuit 10, but there are cases in which gate drive signal 23 would be rendered unnecessary depending on the form of igniter 7.
  • Figure 6 is a diagram that shows one example of the structure of power-supply device control circuit 24 shown in Figure 5.
  • Lamp current signal 21 and lamp voltage signal 20 that were detected in the diagram are assumed to have positive polarity, and are optionally input to the power-supply device control circuit 24 in question via buffer 25 and buffer 38, respectively.
  • Lamp current signal 21 is input to error integrator 31 comprising operational amplifier 27 and substrate 30 via resistor 26.
  • output from maximum current signal generator 29 assumed to have negative polarity is input to operational amplifier 27 via resistor 28.
  • the difference between the current set by maximum current signal generator 29 and lamp current signal 21 is integrated by capacitor 30 and output from error integrator 31.
  • the output from error integrator 31 is output to overcurrent signal 36 via inverter 35 comprising resistor 32, resistor 33, operational amplifier 34.
  • lamp current signal 21 is combined with lamp voltage signal 20 by operator 39 to create power signal 40 which is input via resistor 41 to error integrator 46 comprising operational amplifier 42 and capacitor 45.
  • error integrator 46 comprising operational amplifier 42 and capacitor 45.
  • the output from rated power signal generator 44 assumed to have negative polarity is input to operational amplifier 42 via resistor 43, and the difference in power between power signal 40 from error integrator 46 and the power determined by rated power signal generator 44 is integrated by capacitor 45 and then output.
  • error integrator 46 is output as overcurrent signal 51 via inverter 50 comprising resistor 47, resistor 48, and operational amplifier 49.
  • Overcurrent signal 36 and overcurrent signal 51 are pulled down by resistor 53 via diode 37 and diode 52, respectively, with the result that the higher signal of either overcurrent signal 36 or overcurrent signal 51 is output to resistor 53 as step-down chopper control signal 54.
  • Overcurrent signal 36 becomes the higher signal when lamp current signal 21 is greater than a power value determined by maximum current signal generator 29, while overcurrent signal 51 becomes the higher signal when power signal 40 is greater than a power value determined by rated power signal generator 44. Accordingly, overcurrent signal 36 and the larger of the overcurrent signals appears preferentially in resistor 53.
  • Step-down chopper control signal 54 compares the output signals of saw-tooth wave generator 55 by comparator 56. A high level signal when step-down chopper control signal 54 is smaller than the output signal of saw-tooth wave generator 55 or a low level signal when step-down chopper control signal 54 is greater than the output signal of saw-tooth wave generator 55 is output to gate drive circuit 12 of switch device 11 as gate drive signal 22.
  • gate drive circuit 12 If logic of gate drive circuit 12 is designed so that switch device 11 turns ON when gate drive signal 22 is at a high level, feedback control is instituted so that lamp current signal 21 would match the current determined by maximum current signal generator 29 when overcurrent signal 36 is the higher of overcurrent signal 36 or overcurrent signal 51, or conversely so that power signal 40 would match the power determined by rated power signal generator 44 when overcurrent signal 51 is the higher since the duration during which gate drive signal 22 is at the high level becomes shorter as step-down chopper control signal 54 rises.
  • power-supply device 2 for electric discharge lamps with the function of controlling lamp current Ia so that lamp power Pa would become predetermined rated power Pas, and with the function of controlling lamp current la so that lamp current Ia would not exceed predetermined maximum current Ias can be realized in which the function of controlling lamp current Ia so that said maximum current Ias would not be exceeded takes priority over the function of controlling lamp current Ia so that lamp power Pa would become said rated power Pas.
  • resistor 26 could be set at a low resistance value and/or capacitor 30 could be set at a small electrostatic capacitance value while the response of error integrator 31 in order to control maximum current Ias could be set at a high speed to implement the invention in this implementation mode. If adequate results are not attained by these steps alone, the inductance on the secondary side of transformer 8 of igniter 7 could be increased, coil 9 could be added or both could be completed.
  • the operating frequency of step-down chopper 16 specifically, the oscillation frequency of saw-tooth wave generator 55, must be high enough to support the high speed control required for maximum current Ias. Reducing the electrostatic capacitance of smoothing capacitor 15 in a range such that ripples of step-down chopper 16 does not become excessive would be useful.
  • FIG. 5 and Figure 6 are presented to explain the basic structure of the power-supply device for electric discharge lamps pursuant to the present invention, but additional components or additional circuits such as protective circuits or noise filters may be added to ensure safe circuit operation or safe unit operation as required in the actual implementation, or means such as circuit simplification may also be necessary.
  • inverters 35 and 50 were added to simplify the explanation, but these may be omitted.
  • This implementation mode concerns a power-supply device for electric discharge lamps with functions added to more reliably prevent extinguishing of the power-supply device for electric discharge lamps obtained in the first implementation mode.
  • Lamp current Ia is controlled so that lamp power Pa becomes predetermined rated power Pas even if the lamp voltage Va should fluctuate accompanying change of the impedance between electrodes in the power-supply device for mercury vapor lamps shown in Figure 7. At that time, very great lamp current Ia must flow to attain rated power Pas if lamp voltage Va is very low, but lamp current Ia is controlled so that lamp current Ia does not exceed predetermined maximum current Ias to prevent breakdown of the circuit elements installed in the actual power supply device. This function takes priority over controlling lamp current Ia so that lamp power Pa would become predetermined rated power Pas. Furthermore, the same diagram shows that maximum voltage Vas is determined, but this is a restriction to ensure that the required maximum limitation voltage is not exceeded to ensure safety during no-load switching. Based on said results, the voltage current characteristics of general power-supply devices for electric discharge lamps basically form the hyperbola H shown in Figure 7.
  • Figure 8 (a), (b), (c) are diagrams showing the periodic courses of lamp current Ia, lamp voltage Va and lamp power Pa during this period.
  • lamp current Ia is greater than lamp current Iao immediately before the rapid increase in impedance of the high-pressure mercury vapor lamp, as shown in Figure 8 (a), and falls, presenting the possibility of the lamp extinguishing.
  • Figure 9 is a diagram showing the intended voltage current characteristics in the invention pursuant to this implementation mode.
  • Figure 10 (a), (b), (c) are diagrams showing the periodic courses of simulated lamp current Ia', simulated lamp voltage Va' and simulated lamp power Pa' during this period.
  • the issue of the present invention could be more reliably attained by adding a function to the power-supply device for electric discharge lamps pursuant to this implementation mode wherein the duration of residence in range U in which the current is at least 70% of simulated lamp current Iao' at point A exceeds 50 ms.
  • Thermion release must be rapidly activated to maintain discharge, but prolonging duration Tu to control the current so as to recover to at least 70% of simulated lamp current Iao' immediately preceding the rapid increase in impedance of the high-pressure mercury vapor lamp would be useful in preventing lamp extinguishing.
  • a duration above 70 ms would be preferable in that it would permit the issue of the present invention to be attained with a reserve, and a duration above 100 ms would be still better.
  • the power-supply device for electric discharge lamps shown in Figures 5 and 6 to implement the invention in this implementation mode would be designed so that duration Tu of control so that the current recovers to at least 70% of simulated lamp current Iao' immediately preceding rapid increase in the impedance of high-pressure mercury vapor discharge lamp 1 exceeds 50 ms when the impedance of high-pressure mercury vapor discharge lamp 1 rapidly increases in the operational state in which the simulated lamp current Ia' is controlled so as not to exceed maximum current Ias.
  • resistor 41 has great resistance and/or capacitor 45 has great electrostatic capacitance
  • the response of error integrator 46 would be designed to reach a lower speed in order to control rated power Pas.
  • Figure 11 is a diagram showing a test circuit for detecting a power-supply device for electric discharge lamps in which the lamp does not extinguish.
  • a power-supply device for electric discharge lamps in which the lamp does not extinguish.
  • Such a device is used in high-pressure mercury vapor lamps with a comparatively large amount of mercury sealed within so that 0.15 mg or more of mercury per 1 mm 3 volume of discharge space and 1 x 10 -7 moles of halogen per 1 mm 3 of said discharge space are sealed within.
  • the high-pressure mercury vapor lamp used in this implementation mode is explained on the assumption that arc discharge resistance Ra during arc discharge of 5 ⁇ and glow discharge resistance Rb during glow discharge of 300 ⁇ are used, just as in the first implementation mode.
  • reference numbers 70 and 71 denote resistors of 5 ⁇ and 300 ⁇ resistance that are connected in series to the output terminal of power-supply device 2 for electric discharge lamps.
  • the other structures are identical with those in the structure shown in Figure 2 designated by the same notation and are omitted.
  • resistor 70 is set to a value equal to arc discharge resistance Ra during arc discharge so that roughly the same current as the current flowing during arc discharge when liquid mercury is present on the cathode of an actual high-pressure mercury vapor lamp flows through resistor 70
  • resistor 70 + resistor 71 are set to a value equal to glow discharge resistance Rb so that roughly the same current as the current flowing during glow discharge of a high-pressure mercury vapor lamp flows through resistors 70, 71.
  • Figure 12 is a diagram showing the periodic change in simulated lamp current Ia' and simulated lamp voltage Va' when the state is switched from connection only of resistor 70 to serial connection of resistor 70 and resistor 71.
  • This cathode surface area is the surface area of the entire electrode having a cathode effect that is exposed in the discharge space.
  • the reason that the capacity to provide simulated glow discharge current Iag' in the steady state should increase proportionally to the cathode surface area Sc is that discharge takes place over the entire cathode surface in glow discharge, in contrast to arc discharge. If the capacity to provide current whose size is proportional to the cathode surface area is lacking, the electrode surface could not be heated enough to permit transition to arc discharge due to thermion release. A capacity to provide simulated glow discharge current of lag' ⁇ 0.016 x Sc would be more desirable.
  • time ⁇ required for output voltage Vag' to reach 90% of the voltage in the steady state should be under 170 ⁇ s is that glow discharge could not be maintained and discharge would be discontinued if the time were longer. By the time the voltage had subsequently risen adequately, the electrode would already have cooled, resulting in a high probability of the lamp extinguishing. Time ⁇ ⁇ 100 ⁇ s would be more desirable.
  • Figure 13 is a diagram that shows the structure of the power-supply device for electric discharge lamps pursuant to this implementation mode.
  • reference number 72 denotes a smoothing capacitor 72 that is mounted to permit parallel connection with smoothing capacitor 15
  • 73 denotes a FET that switches insertion/removal of smoothing capacitor 72
  • 74 denotes a gate drive circuit that switches FET 73.
  • the other structures are identical with those in the structure shown in Figure 5 designated by the same notation and are omitted.
  • Figure 14 is a diagram that shows the periodic details of lamp voltage of a high-pressure mercury vapor lamp pursuant to this implementation mode when a high-pressure mercury vapor lamps is first lit.
  • smoothing capacitor 15 and FET 73 in parallel turn ON and the capacitance of the smoothing capacitor is increased by inserting smoothing capacitor 72.
  • the invention of this implementation mode prevents lamp flicking and extinguishing due to said acoustic resonance by turning on FET 73 after the transition to thermal arc discharge following elapse of a period of high impedance during glow discharge, whereupon smoothing capacitor 15 and smoothing capacitor 16 are connected in parallel to increase the capacitance of the smoothing capacitor, as shown in Figure 14.
  • the present invention can be used in a power-supply device for electric discharge lamps to light high-luminance high-pressure mercury vapor lamps that are used as the light source in projectors, for example.

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  • Circuit Arrangements For Discharge Lamps (AREA)
  • Projection Apparatus (AREA)
EP20000917356 1999-04-21 2000-04-19 Dispositif d'alimentation pour lampe a decharge Ceased EP1139700A4 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP11426999 1999-04-21
JP11426999 1999-04-21
JP2000105274A JP3823680B2 (ja) 1999-04-21 2000-04-06 放電灯用給電装置
JP2000105274 2000-04-06
PCT/JP2000/002537 WO2000065885A1 (fr) 1999-04-21 2000-04-19 Dispositif d'alimentation pour lampe a decharge

Publications (3)

Publication Number Publication Date
EP1139700A1 true EP1139700A1 (fr) 2001-10-04
EP1139700A4 EP1139700A4 (fr) 2002-03-28
EP1139700A9 EP1139700A9 (fr) 2002-04-03

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Application Number Title Priority Date Filing Date
EP20000917356 Ceased EP1139700A4 (fr) 1999-04-21 2000-04-19 Dispositif d'alimentation pour lampe a decharge

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EP (1) EP1139700A4 (fr)
JP (1) JP3823680B2 (fr)
WO (1) WO2000065885A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6605906B2 (en) 2001-05-11 2003-08-12 Ushiodenki Kabushiki Kaisha Light source device

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6552498B1 (en) * 2001-09-28 2003-04-22 Osram Sylvania Inc. Method and circuit for controlling current in a high pressure discharge lamp
DE102004021858A1 (de) * 2004-05-04 2005-12-01 BSH Bosch und Siemens Hausgeräte GmbH Haushaltsgerät mit Innenraumbeleuchtung und Beleuchtungsbaugruppe dafür
ATE499824T1 (de) * 2005-01-03 2011-03-15 Koninkl Philips Electronics Nv Verfahren und überwachungsanordnung zur überwachung der quecksilberkondensation in einer bogenentladungsröhre
JP2006344495A (ja) 2005-06-09 2006-12-21 Ushio Inc 放電ランプ点灯装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5332970A (en) * 1992-06-25 1994-07-26 General Electric Company Method for measuring the impedance of an electrodeless arc discharge lamp
JPH07176391A (ja) * 1993-03-03 1995-07-14 Ushio Inc 放電ランプ点灯方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0744076B2 (ja) * 1985-10-15 1995-05-15 東芝ライテック株式会社 放電灯点灯装置
JPH0542637Y2 (fr) * 1988-04-25 1993-10-27

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5332970A (en) * 1992-06-25 1994-07-26 General Electric Company Method for measuring the impedance of an electrodeless arc discharge lamp
US5479102A (en) * 1992-06-25 1995-12-26 General Electric Company Simulated load circuit for simulating the arc impedance of an electrodless discharge lamp
JPH07176391A (ja) * 1993-03-03 1995-07-14 Ushio Inc 放電ランプ点灯方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 1995, no. 10, 30 November 1995 (1995-11-30) -& JP 07 176391 A (USHIO INC), 14 July 1995 (1995-07-14) *
See also references of WO0065885A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6605906B2 (en) 2001-05-11 2003-08-12 Ushiodenki Kabushiki Kaisha Light source device

Also Published As

Publication number Publication date
JP3823680B2 (ja) 2006-09-20
EP1139700A9 (fr) 2002-04-03
JP2001006895A (ja) 2001-01-12
EP1139700A4 (fr) 2002-03-28
WO2000065885A1 (fr) 2000-11-02

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