KR20100133661A - Lcd black-light comprising u-shaped lamp - Google Patents

Lcd black-light comprising u-shaped lamp Download PDF

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Publication number
KR20100133661A
KR20100133661A KR1020090052332A KR20090052332A KR20100133661A KR 20100133661 A KR20100133661 A KR 20100133661A KR 1020090052332 A KR1020090052332 A KR 1020090052332A KR 20090052332 A KR20090052332 A KR 20090052332A KR 20100133661 A KR20100133661 A KR 20100133661A
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KR
South Korea
Prior art keywords
shaped
lamps
lamp
backlight device
secondary windings
Prior art date
Application number
KR1020090052332A
Other languages
Korean (ko)
Inventor
한승호
Original Assignee
삼성전기주식회사
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Publication date
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Priority to KR1020090052332A priority Critical patent/KR20100133661A/en
Publication of KR20100133661A publication Critical patent/KR20100133661A/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133604—Direct backlight with lamps
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • 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
    • H05B41/2821—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 single-switch converter or a parallel push-pull converter in the final stage
    • H05B41/2824—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 single-switch converter or a parallel push-pull converter in the final stage using control circuits for the switching element
    • 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
    • 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

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Optics & Photonics (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Circuit Arrangements For Discharge Lamps (AREA)

Abstract

Disclosed is a backlight device including a U-shaped lamp which can reduce the manufacturing cost of the backlight device by increasing the number of lamps that can be driven per transformer. The backlight device including the U-shaped lamp includes a single primary winding and a plurality of secondary windings, and converts an AC voltage input to one end of the primary winding by inductive coupling of the primary winding and the secondary winding. A transformer for boosting and outputting the AC voltages of opposite phases at both terminals of the secondary winding; And a plurality of U-shaped lamps, one end of which is electrically connected to one end of each of the plurality of secondary windings. The other end of each of the plurality of U-shaped lamps may be grounded or connected to a protection circuit for protecting the plurality of U-shaped lamps or a lamp current adjustment circuit for adjusting the magnitude of the current provided to the U-shaped lamp.

Description

Backlit device with a U-shaped lamp {LCD BLACK-LIGHT COMPRISING U-SHAPED LAMP}

The present invention relates to an LCD backlight device, and more particularly, to a backlight device including a U-shaped lamp that can reduce the manufacturing cost of the backlight device by increasing the number of lamps that can be driven per transformer.

In general, liquid crystal displays (hereinafter referred to as "LCDs") have tended to be gradually widened due to their light weight, thinness, and low power consumption. According to this trend, LCDs are used for office automation equipment, audio / video equipment, and the like. On the other hand, the LCD is controlled to transmit the light beam in accordance with the image signal applied to the plurality of control switches arranged in a matrix form to display a desired image on the screen. Since the LCD is not a self-luminous display device, a light source such as a back light is required.

This backlight uses a Cold Cathode Fluorescent tube (hereinafter referred to as "CCFL") as a light source. CCFL is a light source tube using the electron emission phenomenon generated by the strong electric field applied to the surface of the cold cathode, it is easy to low heat generation, high brightness, long life, full color. The CCFL includes a glass tube coated with phosphor on its inner wall and electrodes attached to both ends of the glass tube. The glass tube is encapsulated with a lean gas such as argon and a quantity of mercury. When a voltage is applied between the electrodes across the glass tube, electrons are released to ionize the gas in the glass tube. By ionization and recombination of ions and electrons, a discharge of 253.7 nm is initiated, which excites mercury and generates 254 nm ultraviolet rays. This ultraviolet light stimulates the phosphors applied to the inner wall of the CCFL and emits visible light.

In general, in the case of an edge type backlight in which a CCFL is disposed in an LCD edge direction and diffuses light to the front of the LCD using a light guide plate, a bar-type straight CCFL is mainly used. However, in recent years, as high brightness and high definition LCD are required, a direct type backlight for directly irradiating light onto the front of the LCD is required, and a U-shaped CCFL is mainly used for such a direct type backlight. Conventionally, the lamp was driven by connecting both electrodes of one U-shaped lamp to both terminals of the secondary winding of the transformer provided at the front end of the lamp to favor the structural features of the U-shaped lamp. Since the conventional driving method of the lamp can drive only one lamp per one secondary winding, there is a disadvantage in reducing the manufacturing cost because the number of transformers or windings must be increased when driving a large number of lamps.

An object of the present invention is to provide a backlight device including a U-shaped lamp that can reduce the manufacturing cost of the backlight device by increasing the number of lamps that can be driven per transformer.

The present invention as a technical means for solving the above technical problem,

It has a single primary winding and a plurality of secondary windings, and boosts an AC voltage input to one end of the primary winding by inductive coupling of the primary winding and the secondary winding to oppose each other at both terminals of the secondary winding. Transformers each outputting an AC voltage of a phase; And

A plurality of U-shaped lamps, one end of which is electrically connected to one end of each of the plurality of secondary windings

It provides a backlight device comprising a.

In one embodiment of the present invention, the other end of each of the plurality of U-shaped lamps may be grounded.

In another embodiment of the present invention, the other end of each of the plurality of U-shaped lamps may be connected to a protection circuit for protecting the plurality of U-shaped lamps or a lamp current adjustment circuit for adjusting the magnitude of the current provided to the U-shaped lamp. have.

According to the present invention, the number of lamps that can be driven per transformer is significantly increased, thereby reducing the manufacturing cost of the backlight device.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiment of this invention is provided in order to demonstrate this invention more completely to the person skilled in the art to which this invention belongs. Therefore, it should be noted that the shape and size of the components shown in the drawings may be exaggerated for more clear explanation.

1 is a circuit diagram showing an example of a backlight device including a U-shaped lamp according to an embodiment of the present invention.

As shown in FIG. 1, a backlight device according to an embodiment of the present invention includes a transformer 11 having a plurality of secondary windings 112 and 113 and a plurality of secondary windings 112 and 113 respectively. It includes a plurality of U-shaped lamps 121, 122, 123, 124 one end is connected to each of the two terminals.

In the embodiment shown in FIG. 1, the other end of each of the plurality of U-shaped lamps 121, 122, 123, 124 may be grounded. One end of the secondary windings 112 and 113 detects a voltage or current provided to the lamps 121, 122, 123, and 124 to protect the lamps 121, 122, 123, and 124 from overvoltage / overcurrent. A lamp current adjustment circuit (not shown) for adjusting the magnitude of the current provided to the circuit (not shown) or the lamps 121, 122, 123, and 124 may be connected. Capacitors 131, 132, 133, and 134 may be provided between one end of the secondary windings 112 and 113 and a protection circuit or a lamp current adjustment circuit.

2 is a circuit diagram showing an example of a backlight device including a U-shaped lamp according to another embodiment of the present invention.

As shown in FIG. 2, a backlight device according to another embodiment of the present invention is similar to the embodiment shown in FIG. 1, and includes a plurality of transformers 21 and a plurality of secondary windings 212 and 213. Each of the secondary windings 212 and 213 includes a plurality of U-shaped lamps 221, 222, 223 and 224, one end of which is connected to each of two terminals. In the embodiment shown in FIG. 2, the other end of each of the plurality of U-shaped lamps 221, 222, 223, 224 can be connected to other circuitry required for the backlight device without being directly grounded. For example, the other end of each of the plurality of U-shaped lamps 221, 222, 223, and 224 protects the driving circuit for providing a driving voltage to the lamps 221, 222, 223, and 224 from overvoltage and overcurrent. May be connected to a circuit. As another example, the other end of each of the plurality of U-shaped lamps 221, 222, 223, 224 may be connected to a lamp current adjustment circuit for adjusting the amount of current provided to the lamps 221, 222, 223, 224. have.

In addition, similar to the embodiment shown in FIG. 1, one end of the secondary windings 212 and 213 detects a voltage or a current provided to the lamps 221, 222, 223, and 224 to detect the lamps 221, 222, A protection circuit for protecting 223, 224 from overvoltage / overcurrent or a lamp current adjustment circuit for adjusting the magnitude of the current provided to the lamps 221, 222, 223, 224 may be connected. Capacitors 231, 232, 233, and 234 may be provided between one end of the secondary windings 212 and 213 and a protection circuit or a lamp current adjustment circuit.

3 is a circuit diagram showing an example of a backlight device including a conventional U-shaped lamp. In a backlight device including a conventional U-shaped lamp, both ends of the U-shaped lamps 321 and 322 are connected to both ends of the secondary windings 312 and 313 of the transformer 31 and at the center of the U-shaped lamps 321 and 322. The lamp is configured to emit light by forming a virtual ground. Both ends of the secondary windings 312 and 313 are connected to other circuits necessary for driving a lamp such as an overvoltage / overcurrent protection circuit or a lamp current adjustment circuit through the capacitors 331, 332, 333, and 334.

Hereinafter, with reference to the accompanying drawings will be described in detail the operation and effect of the present invention.

In general, a driving circuit for driving a lamp of a backlight device is called an inverter, and is a device that turns a low DC voltage into an alternating current and turns the lamp to a high voltage by using a transformer.

As shown in FIG. 1 and FIG. 2, when an AC voltage is input to the transformers 11 and 21 primary winding 111, a plurality of secondary windings 112, 113, 212, and 213 are provided in the primary winding 111. The high voltage is induced by the turns ratio with

In each terminal of the plurality of secondary windings 112, 113, 212, and 213, voltages having different phases with the same amplitude are induced. Each terminal of the secondary windings 112, 113, 212, and 213 has a U-shaped lamp 121-124, 221-224, one end of which is connected to each terminal of the plurality of secondary windings 112, 113, 212, and 213. The induced voltage is applied to the U-shaped lamps 121-124 and 22 1-224 through which a current for lamp lighting flows.

In the embodiment shown in FIG. 1, the current passing through the U-shaped lamps 121-124 flows to ground. In the embodiment shown in FIG. 2, the current passing through the U-shaped lamps 212-214 causes the lamp to flow. Circuits additionally needed for driving may be used, for example, overvoltage / overcurrent protection circuits or lamp current regulation circuits.

1 and 2, a backlight device using a U-shaped lamp according to an embodiment of the present invention is a plurality of transformers 11, 12 provided in front of the lamps 121-124, 221-224 One end of the U-shaped lamp is connected to each terminal of each of the secondary windings of the second winding to drive one lamp by a voltage induced in each terminal. Therefore, it is possible to use twice as many lamps as the backlight inverter including the conventional U-shaped lamp shown in FIG.

Therefore, according to the present invention, the number of lamps that can be driven per transformer is remarkably increased, thereby reducing the manufacturing cost of the backlight device.

In the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims and their equivalents.

1 is a circuit diagram showing an example of a backlight device including a U-shaped lamp according to an embodiment of the present invention.

2 is a circuit diagram showing an example of a backlight device including a U-shaped lamp according to another embodiment of the present invention.

3 is a circuit diagram showing an example of a backlight device including a conventional U-shaped lamp.

* Description of the symbols for the main parts of the drawings *

11, 21: transformer 111, 211: primary winding

112, 113, 212, 213: Secondary winding 121-124, 212-214: U-shaped lamp

Claims (3)

It has a single primary winding and a plurality of secondary windings, and boosts an AC voltage input to one end of the primary winding by inductive coupling of the primary winding and the secondary winding to oppose each other at both terminals of the secondary winding. Transformers each outputting an AC voltage of a phase; And A plurality of U-shaped lamps, one end of which is electrically connected to one end of each of the plurality of secondary windings Backlight device comprising a. The method of claim 1, And the other end of each of the plurality of U-shaped lamps is grounded. The method of claim 1, And the other end of each of the plurality of U-shaped lamps is connected to a protection circuit for protecting the plurality of U-shaped lamps or a lamp current adjustment circuit for adjusting the magnitude of the current provided to the U-shaped lamp.
KR1020090052332A 2009-06-12 2009-06-12 Lcd black-light comprising u-shaped lamp KR20100133661A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020090052332A KR20100133661A (en) 2009-06-12 2009-06-12 Lcd black-light comprising u-shaped lamp

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020090052332A KR20100133661A (en) 2009-06-12 2009-06-12 Lcd black-light comprising u-shaped lamp

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KR20100133661A true KR20100133661A (en) 2010-12-22

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