JP2004335422A - Discharge lamp lighting device - Google Patents

Discharge lamp lighting device Download PDF

Info

Publication number
JP2004335422A
JP2004335422A JP2003133643A JP2003133643A JP2004335422A JP 2004335422 A JP2004335422 A JP 2004335422A JP 2003133643 A JP2003133643 A JP 2003133643A JP 2003133643 A JP2003133643 A JP 2003133643A JP 2004335422 A JP2004335422 A JP 2004335422A
Authority
JP
Japan
Prior art keywords
discharge
lighting device
secondary windings
discharge lamp
high voltage
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Withdrawn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
JP2003133643A
Other languages
Japanese (ja)
Inventor
Takeo Sakamoto
竹男 坂本
Tomohiro Mizoguchi
智宏 溝口
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.)
Toshiba Lighting and Technology Corp
Original Assignee
Harison Toshiba Lighting 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 Harison Toshiba Lighting Corp filed Critical Harison Toshiba Lighting Corp
Priority to JP2003133643A priority Critical patent/JP2004335422A/en
Priority to KR1020040032885A priority patent/KR100602536B1/en
Priority to TW093113236A priority patent/TWI259740B/en
Priority to CNA2004100434933A priority patent/CN1550850A/en
Publication of JP2004335422A publication Critical patent/JP2004335422A/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/54—Igniting arrangements, e.g. promoting ionisation for starting
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/38—Cold-cathode tubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H01J29/764—Deflecting by magnetic fields only using toroidal windings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H01J29/766—Deflecting by magnetic fields only using a combination of saddle coils and toroidal windings
    • 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
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • 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
    • H05B41/282—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
    • H05B41/2825—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 by means of a bridge converter in the final stage
    • H05B41/2827—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 by means of a bridge converter in the final stage using specially adapted components in the load circuit, e.g. feed-back transformers, piezoelectric transformers; using specially adapted load circuit configurations
    • 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
    • H05B41/282—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
    • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
    • H05B41/2855—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against abnormal lamp operating conditions

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Power Engineering (AREA)
  • Circuit Arrangements For Discharge Lamps (AREA)
  • Planar Illumination Modules (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To light a plurality of discharge lamps so that luminance deviation due to unevenness in stray capacity of load does not occur. <P>SOLUTION: A discharge lamp lighting device is provided with a plurality of discharge tubes 1a, 1b, connected in series, and an electromagnetic transformer T having a common primary winding 11 and two secondary windings 12(1), 12(2). One vacant electrode of the plurality of discharge tubes connected in series is connected to a high voltage terminal of one secondary winding of the electromagnetic transformer. The other vacant electrode of the discharge tubes connected in series is connected to a high voltage terminal of the other secondary winding of the electromagnetic transformer. Low voltage terminals of the two second windings are grounded respectively. Each of the high voltage terminals of the two secondary windings are applied with a voltage of an inverted phase respectively. The lighting device is characterised in that, by making magnetic circuit one, luminance deviation (lamp current) can be prevented, even if unevenness in stray capacity of load exists, thus eliminating luminance unevenness on screen, when used as a backlight arranged on the back side of pannel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、放電灯点灯装置に関する。
【０００２】
【従来の技術】
従来、液晶モニタ、液晶テレビジョン等の直下型バックライトとして使用される複数の放電灯を有する放電灯点灯装置では、図６、図７に示す回路構成であった。すなわち、２本の放電灯１ａ，１ｂを点灯させるために、この２本の放電灯１ａ，１ｂを直列接続し、１次巻線２と２次巻線３とで構成される電磁トランスＴ１，Ｔ２を２個使用し、これらの電磁トランスＴ１，Ｔ２の２次巻線３，３それぞれの低圧端子同士を２本の放電灯１ａ，１ｂそれぞれの低圧側電極と共に接地し、各電磁トランスＴ１，Ｔ２の２次巻線３，３それぞれの高圧端子を放電灯１ａ，１ｂそれぞれの高圧側電極に接続している。そして各電磁トランスＴ１，Ｔ２の１次巻線２，２は高周波電源５に対して反転位相となるように接続し、各２次巻線３，３の高圧端子側に逆位相の出力があるように接続している。
【０００３】
また、従来の放電灯点灯装置として図８に示すように、接地回路構成を簡略化するために、２個の電磁トランスＴ１，Ｔ２の２次巻線３，３の低圧端子同士を接地し、直列接続された放電灯１ａ，１ｂについてはその低圧側電極間は単に接続しただけで、接地しない構成のも知られている。さらには、図９に示すように、２本の放電灯１ａ，１ｂに代えてＵ字型の屈曲管１０を採用し、図８に示した放電灯点灯装置と同様に、２個の電磁トランスＴ１，Ｔ２の２次巻線３，３の低圧端子同士を接地し、屈曲管１０の両電極それぞれを２次巻線３，３の高圧端子それぞれに接続した構成のものも知られている。
【０００４】
【特許文献１】
特許第３２９３５９２号公報
【０００５】
【発明が解決しようとする課題】
ところが、このような従来の放電灯点灯装置では各放電灯の電磁トランスが独立しているため、負荷の浮遊容量等のバラツキにより輝度（ランプ電流）の偏りが発生し、直下型のバックライトとして使用するときに画面上の輝度ムラとなる問題点があった。
【０００６】
本発明はこのような従来の技術的課題に鑑みてなされたもので、負荷の浮遊容量のバラツキに対して輝度の偏りがないように複数本の放電灯を点灯させることができる放電灯点灯装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
請求項１の発明は、複数の直列接続された放電管と、共通の１次巻線と、共通の１次巻線及び２個の２次巻線を有する電磁トランスとを備えた放電灯点灯装置であって、前記電磁トランスの一方の２次巻線の高圧端子に、前記複数の直列接続された放電管の一方の空き電極を接続し、前記電磁トランスの他方の２次巻線の高圧端子に、前記複数の直列接続された放電管の他方の空き電極を接続し、前記２個の２次巻線の低圧端子それぞれを接地し、前記２個の２次巻線の高圧端子それぞれに互いに反転位相の電圧を印加するようにしたことを特徴とするものである。
【０００８】
請求項１の発明の放電灯点灯装置では、磁気回路を１つにすることで、負荷の浮遊容量のバラツキがあって２次巻線の一方に変動が発生すれば他方もほぼ同時に同様の変動を起こし、輝度（ランプ電流）の偏りの発生を防止し、直下型のバックライトとして使用するときに画面上の輝度ムラをなくすことができる。
【０００９】
請求項２の発明は、屈曲した放電管と、共通の１次巻線及び２個の２次巻線を有する電磁トランスとを備えた放電灯点灯装置であって、前記電磁トランスの一方の２次巻線の高圧端子に、前記放電管の一方の電極に接続し、前記電磁トランスの他方の２次巻線の高圧端子に、前記放電管の他方の電極に接続し、前記２個の２次巻線の低圧端子それぞれを接地し、前記２個の２次巻線の高圧端子それぞれに互いに反転位相の電圧を印加するようにしたことを特徴とするものである。
【００１０】
請求項２の発明の放電灯点灯装置では、磁気回路を１つにすることで、負荷の浮遊容量のバラツキがあって２次巻線の一方に変動が発生すれば他方もほぼ同時に同様の変動を起こし、屈曲した放電管の一端と他端とで輝度（ランプ電流）の偏りの発生を防止し、直下型のバックライトとして使用するときに画面上の輝度ムラをなくすことができる。
【００１１】
【発明の実施の形態】
以下、本発明の実施の形態を図に基づいて詳説する。
【００１２】
＜第１の実施の形態＞本発明の第１の実施の形態の放電灯点灯装置について、図１及び図２を用いて説明する。本実施の形態の放電灯点灯装置は、共通の１次巻線１１と２つの２次巻線１２（１），１２（２）、高周波電源回路５に対するベース巻線となる３次巻線１３から構成される電磁トランスＴを使用している。
【００１３】
２本の放電灯１ａ，１ｂを点灯させるために、この２本の放電灯１ａ，１ｂそれぞれの低圧側電極を直列接続し、電磁トランスＴの２次巻線１２（１），１２（２）の低圧端子同士を接地し、電磁トランスＴの２次巻線１２（１），１２（２）それぞれの高圧端子を放電灯１ａ，１ｂそれぞれの高圧側電極に接続している。そして電磁トランスＴの１次巻線１１を高周波電源５に対して接続し、各２次巻線１２（１），１２（２）の高圧端子側に互いに反転位相の出力があるように接続している。
【００１４】
これにより第１の実施の形態の放電灯点灯装置では、電磁トランスＴの共通の１次巻線１１に高周波電源５を接続することにより、一方の２次巻線１２（１）から高圧波形を発生させ、他方の２次巻線１２（２）からは位相反転された高圧波形を発生させ、それぞれを２本の放電灯１ａ，１ｂそれぞれの高圧側電極に印加することで両放電灯１ａ，１ｂを同時に点灯させる。
【００１５】
この放電灯１ａ，１ｂの点灯時には、図１に示すように両放電灯１ａ，１ｂの高圧側電極に互いに反転位相の高周波電圧が印加される。負荷の浮遊容量のバラツキで２次巻線１２（１），１２（２）の高圧側にアンバランスが生じようとしても、電磁トランスＴの磁気回路が共通であるために一方のランプ電流が変動すると他方も同様に変動し、同時にランプ電流が変動し、その結果として同一の輝度を維持することができる。したがって、本実施の形態の放電灯点灯装置を直下型のバックライトとして使用するときに画面上に輝度ムラを発生させることが無く、均一な輝度の照明ができる。
【００１６】
＜第２の実施の形態＞次に、本発明の第２の実施の形態の放電灯点灯装置について、図３を用いて説明する。第２の実施の形態の放電灯点灯装置は、電磁トランスＴの構成は第１の実施の形態と同様である。そして、放電灯としてＵ字屈曲管１０を用い、その両端の電極を電磁トランスＴの互いに反転位相の高電圧高周波を出力する２次巻線１２（１），１２（２）の高圧側端子それぞれに接続している。
【００１７】
この第２の実施の形態の放電灯点灯装置でも、電磁トランスＴの共通の１次巻線１１に高周波電源５を接続することにより、一方の２次巻線１２（１）から高圧波形を発生させ、他方の２次巻線１２（２）からは位相反転された高圧波形を発生させ、それぞれを２本の屈曲管１０の両電極それぞれに印加することで放電点灯させる。
【００１８】
この屈曲管１０の点灯時には、図３に示すように両電極に互いに反転位相の高周波電圧が印加され、負荷の浮遊容量のバラツキで２次巻線１２（１），１２（２）の高圧側にアンバランスが生じようとしても、電磁トランスＴの磁気回路が共通であるために一方のランプ電流が変動すると他方も同様に変動し、同時にランプ電流が変動し、その結果として屈曲管１０の両側の輝度を同一に維持することができる。したがって、本実施の形態の放電灯点灯装置を直下型のバックライトとして使用するときにも画面上に輝度ムラを発生させることがなく、均一な輝度の照明ができる。
【００１９】
なお、屈曲管放電灯１０の電源回路側の出力電極への接続構造は、図４の構造にすることが好ましい。この図４において、２１は放電灯点灯装置の電源装置の筐体に収容される基板であり、この基板２１の高電圧高周波出力部にランド２２（１），２２（２）を設けてある。他方、屈曲管放電灯１０の両電極から引き出し線２３（１），２３（２）が同一方向に引き出してある。そして電源装置に対する屈曲管放電灯１０の接続に際しては、筐体２１のランド２２（１），２２（２）それぞれに対して屈曲管放電灯１０の両引き出し線２３（１），２３（２）それぞれをハンダ付けのような方法で接続し、ワイヤーハーネスを利用しないようにする。
【００２０】
これによって、図５に示したようなワイヤーハーネス２４を利用した接続構成に対して、ワイヤーハーネス２４からのリーク電流をなくして電力の伝達効率の減少を抑えることができる。また、ワイヤーハーネス周辺の浮遊容量の差により生じていた放電灯１０の電極間での点灯電流値の差を抑えることができる。さらには、ワイヤーハーネス２４、ハウジング２５、コネクタ２６、絶縁チューブ２７等の部品を削減できてコストダウンも図れる。
【００２１】
【発明の効果】
以上のように請求項１の発明によれば、磁気回路を１つにすることで、負荷の浮遊容量のバラツキがあって２次巻線の一方に変動が発生すれば他方もほぼ同時に同様の変動を起こし、輝度（ランプ電流）の偏りの発生を防止し、直下型のバックライトとして使用するときに画面上の輝度ムラをなくすことができる。
【００２２】
請求項２の発明によれば、磁気回路を１つにすることで、負荷の浮遊容量のバラツキがあって２次巻線の一方に変動が発生すれば他方もほぼ同時に同様の変動を起こし、屈曲した放電管の一端と他端とで輝度（ランプ電流）の偏りの発生を防止し、直下型のバックライトとして使用するときに画面上の輝度ムラをなくすことができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態の回路ブロック図。
【図２】第１の実施の形態の回路図。
【図３】本発明の第２の実施の形態の回路ブロック図。
【図４】第２の実施の形態における屈曲管放電灯の電源装置筐体に対する接続構造を示す正面図。
【図５】第２の実施の形態における屈曲管放電灯の電源装置筐体に対するワイヤーハーネスを使用する接続構造を示す正面図。
【図６】従来例の回路ブロック図。
【図７】従来例の回路図。
【図８】他の従来例の回路ブロック図。
【図９】さらに他の従来例の回路ブロック図。
【符号の説明】
１ａ，１ｂ 放電灯
５ 高周波電源
１０ 屈曲管（放電灯）
１１ １次巻線
１２（１），１２（２） ２次巻線
Ｔ 電磁トランス[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a discharge lamp lighting device.
[0002]
[Prior art]
Conventionally, a discharge lamp lighting device having a plurality of discharge lamps used as a direct-type backlight such as a liquid crystal monitor and a liquid crystal television has a circuit configuration shown in FIGS. That is, in order to turn on the two discharge lamps 1a and 1b, the two discharge lamps 1a and 1b are connected in series, and the electromagnetic transformer T1, which is composed of the primary winding 2 and the secondary winding 3, T2 is used, and the low voltage terminals of the secondary windings 3 and 3 of these electromagnetic transformers T1 and T2 are grounded together with the low voltage side electrodes of the two discharge lamps 1a and 1b, respectively. The high voltage terminal of each of the secondary windings 3 and 3 of T2 is connected to the high voltage side electrode of each of the discharge lamps 1a and 1b. The primary windings 2 and 2 of each of the electromagnetic transformers T1 and T2 are connected to the high-frequency power supply 5 so as to have an inverted phase, and the secondary windings 3 and 3 have outputs of opposite phases on the high voltage terminal side. Connected.
[0003]
Further, as shown in FIG. 8, as a conventional discharge lamp lighting device, in order to simplify the grounding circuit configuration, the low voltage terminals of the secondary windings 3 and 3 of the two electromagnetic transformers T1 and T2 are grounded. It is also known that the discharge lamps 1a and 1b connected in series are simply connected between the low voltage side electrodes and are not grounded. Further, as shown in FIG. 9, a U-shaped bent tube 10 is employed in place of the two discharge lamps 1a and 1b, and two electromagnetic transformers are provided similarly to the discharge lamp lighting device shown in FIG. There is also known a configuration in which the low voltage terminals of the secondary windings 3 and 3 of T1 and T2 are grounded, and both electrodes of the bent tube 10 are connected to the high voltage terminals of the secondary windings 3 and 3, respectively.
[0004]
[Patent Document 1]
Japanese Patent No. 3293592 [0005]
[Problems to be solved by the invention]
However, in such a conventional discharge lamp lighting device, since the electromagnetic transformer of each discharge lamp is independent, unevenness in luminance (lamp current) occurs due to variations in the stray capacitance of the load and the like, and as a direct-type backlight, There is a problem that brightness unevenness occurs on a screen when used.
[0006]
The present invention has been made in view of such a conventional technical problem, and has a discharge lamp lighting device capable of lighting a plurality of discharge lamps so that there is no deviation in luminance with respect to a variation in a stray capacitance of a load. The purpose is to provide.
[0007]
[Means for Solving the Problems]
A first aspect of the present invention is a discharge lamp lighting apparatus including a plurality of discharge tubes connected in series, a common primary winding, and an electromagnetic transformer having a common primary winding and two secondary windings. A discharge electrode connected to one of the plurality of discharge tubes connected in series to a high-voltage terminal of one of the secondary windings of the electromagnetic transformer; The other empty electrodes of the plurality of series-connected discharge tubes are connected to the terminals, the low-voltage terminals of the two secondary windings are grounded, and the high-voltage terminals of the two secondary windings are connected to the terminals. It is characterized in that voltages of opposite phases are applied to each other.
[0008]
In the discharge lamp lighting device according to the first aspect of the present invention, by using one magnetic circuit, if the stray capacitance of the load varies and one of the secondary windings fluctuates, the other fluctuates almost simultaneously. This can prevent unevenness in brightness (lamp current) from occurring, and can eliminate uneven brightness on the screen when used as a direct-type backlight.
[0009]
The invention according to claim 2 is a discharge lamp lighting device including a bent discharge tube and an electromagnetic transformer having a common primary winding and two secondary windings, wherein one of the electromagnetic transformers The high voltage terminal of the secondary winding is connected to one electrode of the discharge tube, and the high voltage terminal of the other secondary winding of the electromagnetic transformer is connected to the other electrode of the discharge tube. The low voltage terminals of the secondary windings are grounded, and voltages having phases opposite to each other are applied to the high voltage terminals of the two secondary windings.
[0010]
In the discharge lamp lighting device according to the second aspect of the present invention, by using a single magnetic circuit, if the stray capacitance of the load varies and one of the secondary windings fluctuates, the other fluctuates almost simultaneously. As a result, uneven brightness (lamp current) is prevented from occurring at one end and the other end of the bent discharge tube, and uneven brightness on the screen can be eliminated when used as a direct-type backlight.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
<First Embodiment> A discharge lamp lighting device according to a first embodiment of the present invention will be described with reference to FIGS. The discharge lamp lighting device according to the present embodiment includes a common primary winding 11, two secondary windings 12 (1), 12 (2), and a tertiary winding 13 serving as a base winding for the high-frequency power supply circuit 5. Is used.
[0013]
In order to turn on the two discharge lamps 1a and 1b, the low voltage side electrodes of the two discharge lamps 1a and 1b are connected in series, and the secondary windings 12 (1) and 12 (2) of the electromagnetic transformer T are connected. Of the secondary windings 12 (1) and 12 (2) of the electromagnetic transformer T are connected to the high-voltage side electrodes of the discharge lamps 1a and 1b. Then, the primary winding 11 of the electromagnetic transformer T is connected to the high-frequency power supply 5, and the secondary windings 12 (1) and 12 (2) are connected so that the high voltage terminals of the secondary windings 12 (1) and 12 (2) have mutually inverted phases. ing.
[0014]
Thus, in the discharge lamp lighting device according to the first embodiment, by connecting the high-frequency power supply 5 to the common primary winding 11 of the electromagnetic transformer T, a high-voltage waveform is output from one secondary winding 12 (1). Then, a high-voltage waveform whose phase is inverted is generated from the other secondary winding 12 (2) and applied to the high-voltage side electrodes of the two discharge lamps 1a and 1b, respectively. 1b are turned on simultaneously.
[0015]
When the discharge lamps 1a and 1b are turned on, high-frequency voltages having phases opposite to each other are applied to the high-voltage side electrodes of the discharge lamps 1a and 1b as shown in FIG. Even if an imbalance occurs on the high voltage side of the secondary windings 12 (1) and 12 (2) due to variations in the stray capacitance of the load, one lamp current fluctuates because the magnetic circuit of the electromagnetic transformer T is common. Then, the other also fluctuates, and at the same time, the lamp current fluctuates. As a result, the same luminance can be maintained. Therefore, when the discharge lamp lighting device of the present embodiment is used as a direct type backlight, luminance unevenness does not occur on the screen, and illumination with uniform luminance can be performed.
[0016]
<Second Embodiment> Next, a discharge lamp lighting device according to a second embodiment of the present invention will be described with reference to FIG. In the discharge lamp lighting device of the second embodiment, the configuration of the electromagnetic transformer T is the same as that of the first embodiment. Then, a U-shaped bent tube 10 is used as a discharge lamp, and the electrodes at both ends of the U-shaped bent tube 10 are connected to the high voltage side terminals of the secondary windings 12 (1) and 12 (2) of the electromagnetic transformer T which output high voltage and high frequency in mutually inverted phases. Connected to
[0017]
Also in the discharge lamp lighting device according to the second embodiment, the high frequency power supply 5 is connected to the common primary winding 11 of the electromagnetic transformer T to generate a high-voltage waveform from one of the secondary windings 12 (1). Then, a high-voltage waveform whose phase is inverted is generated from the other secondary winding 12 (2), and the high-voltage waveform is applied to each of the two electrodes of the two bent tubes 10 to perform discharge lighting.
[0018]
When the bent tube 10 is turned on, as shown in FIG. 3, high-frequency voltages having phases opposite to each other are applied to both electrodes, and the high-voltage side of the secondary windings 12 (1) and 12 (2) is changed due to variation in the stray capacitance of the load. Even if an imbalance occurs, if the lamp current fluctuates because the magnetic circuit of the electromagnetic transformer T is common, the other fluctuates as well, and the lamp current fluctuates at the same time. Can be kept the same. Therefore, even when the discharge lamp lighting device according to the present embodiment is used as a direct type backlight, luminance unevenness does not occur on the screen, and illumination with uniform luminance can be performed.
[0019]
The connection structure of the bent tube discharge lamp 10 to the output electrode on the power supply circuit side is preferably the structure shown in FIG. In FIG. 4, reference numeral 21 denotes a substrate accommodated in a housing of a power supply device of the discharge lamp lighting device, and lands 22 (1) and 22 (2) are provided on a high-voltage high-frequency output portion of the substrate 21. On the other hand, lead wires 23 (1) and 23 (2) are drawn out from both electrodes of the bent tube discharge lamp 10 in the same direction. When the bent tube discharge lamp 10 is connected to the power supply device, the both leads 23 (1) and 23 (2) of the bent tube discharge lamp 10 are connected to the lands 22 (1) and 22 (2) of the housing 21, respectively. Connect each one in a soldering-like way and avoid using wire harnesses.
[0020]
As a result, in the connection configuration using the wire harness 24 as shown in FIG. 5, it is possible to eliminate a leak current from the wire harness 24 and suppress a decrease in power transmission efficiency. Further, it is possible to suppress the difference in the lighting current value between the electrodes of the discharge lamp 10 caused by the difference in the stray capacitance around the wire harness. Further, the number of components such as the wire harness 24, the housing 25, the connector 26, and the insulating tube 27 can be reduced, and the cost can be reduced.
[0021]
【The invention's effect】
As described above, according to the first aspect of the present invention, by using a single magnetic circuit, if the stray capacitance of the load varies and one of the secondary windings fluctuates, the other is almost the same. Variations can be prevented to prevent the occurrence of uneven brightness (lamp current), and uneven brightness on the screen can be eliminated when used as a direct-type backlight.
[0022]
According to the second aspect of the present invention, by using a single magnetic circuit, if the stray capacitance of the load varies and one of the secondary windings fluctuates, the other also causes the same fluctuation almost simultaneously, An uneven brightness (lamp current) can be prevented from occurring at one end and the other end of the bent discharge tube, and uneven brightness on the screen can be eliminated when used as a direct backlight.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram according to the first embodiment;
FIG. 3 is a circuit block diagram according to a second embodiment of the present invention.
FIG. 4 is a front view showing a connection structure of a bent tube discharge lamp to a power supply device housing according to the second embodiment.
FIG. 5 is a front view showing a connection structure using a wire harness to a power supply housing of a bent tube discharge lamp according to a second embodiment.
FIG. 6 is a circuit block diagram of a conventional example.
FIG. 7 is a circuit diagram of a conventional example.
FIG. 8 is a circuit block diagram of another conventional example.
FIG. 9 is a circuit block diagram of still another conventional example.
[Explanation of symbols]
1a, 1b Discharge lamp 5 High frequency power supply 10 Bend tube (discharge lamp)
11 Primary winding 12 (1), 12 (2) Secondary winding T Electromagnetic transformer

Claims (2)

複数の直列接続された放電管と、共通の１次巻線及び２個の２次巻線を有する電磁トランスとを備えた放電灯点灯装置であって、
前記電磁トランスの一方の２次巻線の高圧端子に、前記複数の直列接続された放電管の一方の空き電極を接続し、前記電磁トランスの他方の２次巻線の高圧端子に、前記複数の直列接続された放電管の他方の空き電極を接続し、前記２個の２次巻線の低圧端子それぞれを接地し、
前記２個の２次巻線の高圧端子それぞれに互いに反転位相の電圧を印加するようにしたことを特徴とする放電灯点灯装置。A discharge lamp lighting device comprising: a plurality of discharge tubes connected in series; and an electromagnetic transformer having a common primary winding and two secondary windings,
The high voltage terminal of one secondary winding of the electromagnetic transformer is connected to one free electrode of the plurality of discharge tubes connected in series, and the high voltage terminal of the other secondary winding of the electromagnetic transformer is connected to the high voltage terminal of the other secondary winding. The other free electrode of the discharge tube connected in series is connected, and the low voltage terminals of the two secondary windings are grounded,
A discharge lamp lighting device characterized in that voltages of opposite phases are applied to the respective high voltage terminals of the two secondary windings. 屈曲した放電管と、共通の１次巻線及び２個の２次巻線を有する電磁トランスとを備えた放電灯点灯装置であって、
前記電磁トランスの一方の２次巻線の高圧端子に、前記放電管の一方の電極を接続し、前記電磁トランスの他方の２次巻線の高圧端子に、前記放電管の他方の電極を接続し、前記２個の２次巻線の低圧端子それぞれを接地し、
前記２個の２次巻線の高圧端子それぞれに互いに反転位相の電圧を印加するようにしたことを特徴とする放電灯点灯装置。A discharge lamp lighting device including a bent discharge tube and an electromagnetic transformer having a common primary winding and two secondary windings,
One electrode of the discharge tube is connected to a high voltage terminal of one secondary winding of the electromagnetic transformer, and the other electrode of the discharge tube is connected to a high voltage terminal of the other secondary winding of the electromagnetic transformer. And grounding each of the low voltage terminals of the two secondary windings,
A discharge lamp lighting device characterized in that voltages of opposite phases are applied to the respective high voltage terminals of the two secondary windings.
JP2003133643A 2003-05-12 2003-05-12 Discharge lamp lighting device Withdrawn JP2004335422A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2003133643A JP2004335422A (en) 2003-05-12 2003-05-12 Discharge lamp lighting device
KR1020040032885A KR100602536B1 (en) 2003-05-12 2004-05-11 Discharge lamp lighting apparatus and back light apparatus using the same
TW093113236A TWI259740B (en) 2003-05-12 2004-05-11 Lighting apparatus of discharging lamp and back illuminating apparatus using the same
CNA2004100434933A CN1550850A (en) 2003-05-12 2004-05-12 Discharge lamp lighting device and back lighting lamp device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003133643A JP2004335422A (en) 2003-05-12 2003-05-12 Discharge lamp lighting device

Publications (1)

Publication Number Publication Date
JP2004335422A true JP2004335422A (en) 2004-11-25

Family

ID=33508116

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003133643A Withdrawn JP2004335422A (en) 2003-05-12 2003-05-12 Discharge lamp lighting device

Country Status (4)

Country Link
JP (1) JP2004335422A (en)
KR (1) KR100602536B1 (en)
CN (1) CN1550850A (en)
TW (1) TWI259740B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007099683A1 (en) * 2006-02-28 2007-09-07 Murata Manufacturing Co., Ltd. Discharge lamp lighting circuit and electronic device
WO2008133024A1 (en) * 2007-04-19 2008-11-06 Sumida Corporation Discharge tube driving device
US7622870B2 (en) 2006-04-13 2009-11-24 Rohm Co., Ltd. Inverter apparatus
US7710230B2 (en) 2005-10-04 2010-05-04 Darfon Electronics Corp. Transformer of light tube driving device and method for adjusting light tube using thereof
US8264162B2 (en) 2008-06-05 2012-09-11 Rohm Co., Ltd. Inverter apparatus

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1993008B (en) * 2005-12-30 2011-06-22 鸿富锦精密工业（深圳）有限公司 Discharge lamp driving apparatus
US7586271B2 (en) 2006-04-28 2009-09-08 Hong Kong Applied Science and Technology Research Institute Co. Ltd Efficient lighting

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7710230B2 (en) 2005-10-04 2010-05-04 Darfon Electronics Corp. Transformer of light tube driving device and method for adjusting light tube using thereof
WO2007099683A1 (en) * 2006-02-28 2007-09-07 Murata Manufacturing Co., Ltd. Discharge lamp lighting circuit and electronic device
EP1991034A1 (en) * 2006-02-28 2008-11-12 Murata Manufacturing Co. Ltd. Discharge lamp lighting circuit and electronic device
US7683555B2 (en) 2006-02-28 2010-03-23 Murata Manufacturing Co., Ltd. Discharge tube lighting circuit and electronic apparatus provided with the discharge tube lighting circuit
EP1991034A4 (en) * 2006-02-28 2014-04-16 Murata Manufacturing Co Discharge lamp lighting circuit and electronic device
US7622870B2 (en) 2006-04-13 2009-11-24 Rohm Co., Ltd. Inverter apparatus
WO2008133024A1 (en) * 2007-04-19 2008-11-06 Sumida Corporation Discharge tube driving device
CN101663921A (en) * 2007-04-19 2010-03-03 胜美达集团株式会社 Discharge tube driving device
KR101083384B1 (en) * 2007-04-19 2011-11-14 스미다 코포레이션 가부시키가이샤 Discharge tube driving device
US8129919B2 (en) 2007-04-19 2012-03-06 Sumida Corporation Discharge tube driving device
US8264162B2 (en) 2008-06-05 2012-09-11 Rohm Co., Ltd. Inverter apparatus

Also Published As

Publication number Publication date
TWI259740B (en) 2006-08-01
KR100602536B1 (en) 2006-07-19
KR20040097905A (en) 2004-11-18
TW200427375A (en) 2004-12-01
CN1550850A (en) 2004-12-01

Similar Documents

Publication Publication Date Title
JP4237186B2 (en) Multi lamp drive system
KR200352353Y1 (en) Transformer and voltage supply circuit thereof for lighting tubes
US7683555B2 (en) Discharge tube lighting circuit and electronic apparatus provided with the discharge tube lighting circuit
JP2004214488A (en) Inverter transformer
JPWO2008090722A1 (en) Liquid crystal display
US8167451B2 (en) Backlight device and liquid crystal display device
JP2004335422A (en) Discharge lamp lighting device
JP2005012176A (en) Inverter transformer and discharge lamp lighting device using the same
JP2001350133A (en) Liquid crystal display device
JP2005032940A (en) Inverter transformer and discharge lamp lighting device using the same
US7965164B2 (en) Multi-output transformer
WO2007007520A1 (en) Transformer
KR101015652B1 (en) Spilt-Type Multi-Output Transformer
US20070046616A1 (en) Liquid crystal display apparatus and backlight module thereof
JP2008153384A (en) Transformer and backlighting device as well as display device
US20100181927A1 (en) Multi-lamp driving circuit
KR100611033B1 (en) Fluorescent lamp with coil antenna and surface light source device using the same
US20090316079A1 (en) Backlight device, liquid crystal display device, and method for assembling backlight device
KR100975918B1 (en) Embedding-Type Multi-Output Transformer
JP2006040871A (en) Lighting apparatus driving device
US6570341B2 (en) Electromagnetic ballast for serially connected gaseous discharge lamps
JP2002343591A (en) Lighting device for multi-tube type discharge tube
JP2001268941A (en) Inverter circuit unit
KR20040101057A (en) Inverter transformer and discharge lamp lighting apparatus using the same
JP4586767B2 (en) Liquid crystal display

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060313

A761 Written withdrawal of application

Free format text: JAPANESE INTERMEDIATE CODE: A761

Effective date: 20070720