Patent Application
20080061709
The above and other aspects, features and advantages of the present invention will become readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout.
It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower”, can therefore, encompasses both an orientation of “lower” and “upper,” depending of the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Exemplary embodiments of the present invention are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present invention.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to accompanying drawings. However, the scope of the present invention is not limited to such exemplary embodiments and the present invention may be realized in various forms.
Referring to
The inverter circuit 110 includes one inverter 111, one inverter transformer 112, two balance transformers 113 and 114 and a current detection transformer 115.
The inverter 111 controls an output signal based on a current detection value fedback from the current detection transformer 115. The inverter transformer 112 includes one primary coil 1121 connected to an output terminal of the inverter 111. In addition, the inverter transformer 112 includes two pairs of secondary coils 1122, 1123, 1124 and 1125 connected to first end portions of two pairs of the CCFLs 120. The two pairs of the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112 provide an AC high voltage, which is induced by the primary coil 1121, to the two pairs of CCFLs 120. Second end portions of the two pairs of the CCFLs 120 are connected to a ground GND.
Since the CCFL 120 is driven by a high voltage, static noise radiated from the CCFL 120 is substantial. Accordingly, since the static noise affects a liquid crystal display (“LCD”) apparatus, the static noise radiated from the CCFL 120 is canceled by phase-shifting the output of the CCFL 120 by 180 degrees. As shown in
A primary coil 1131 of the balance transformer 113 is serially connected to the secondary coils 1122 and 1123 of the inverter transformer 112. A primary coil 1141 of the balance transformer 114 is serially connected to the secondary coils 1124 and 1125 of the inverter transformer 112.
Secondary coils 1132 and 1142 of the two balance transformers 113 and 114 are serially connected to each other, thereby forming a loop. A portion of the loop formed by the secondary coils 1132 and 1142 of the two balance transformers 113 and 114 is connected to the ground GND.
A primary coil 1151 of a current detection transformer 115 is serially connected to the secondary coils 1132 and 1142 of the two balance transformers 113 and 114. A secondary coil 1152 of the current detection transformer 115 is connected between the inverter 111 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the primary coil 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverter 111.
Referring to
An input terminal of the current-voltage converter 1111 is connected to the secondary coil 1152 of the current detection transformer 115. An output terminal of the current-voltage converter 1111 is connected to a first input terminal of the comparator 1113. An output terminal of the reference voltage generator 1112 is connected to a second input terminal of the comparator 1113.
An output terminal of the comparator 1113 is connected to an input terminal of the pulse generator 1114. An output terminal of the pulse generator 1114 is connected to an input terminal of the switching circuit 1115. An output terminal of the switching circuit 1115 is connected to the primary coil 1121 of the inverter transformer 112.
The current-voltage converter 1111 converts the current detection value output from the current detection transformer 115 into a voltage detection value to provide the voltage detection value to the comparator 1113. The comparator 1113 compares the voltage detection value from the current-voltage converter 1111 with a reference voltage value from the reference voltage generator 1112 and then generates a voltage difference between the voltage detection value and the reference voltage value. The comparator 1113 then provides the voltage difference to the pulse generator 1114.
The pulse generator 1114 generates a pulse signal including a pulse width controlled according to the voltage difference output from the comparator 1113 in order to provide the pulse signal to the switching circuit 1115. The switching circuit 1115 generates an AC voltage based on the pulse signal output from the pulse generator 1114 in order to provide the AC voltage to the primary coil 1121 of the inverter transformer 112.
Since the inverter 111 controls the AC voltage of an output signal based on a current detection value fedback from the current detection transformer 115 serially connected to the secondary coils 1132 and 1142 of the two balance transformers 113 and 114, a proper AC voltage may be provided to the primary coil 1121 of the inverter transformer 112. However, the present invention is not limited to a number of balance transformers 113 and 114 connected to the current detection transformer 115.
According to the first exemplary embodiment of the present invention, current flowing through the two pairs of the CCFLs 120 is uniformly maintained by an operation of the two balance transformers 113 and 114 since the primary coils 1131 and 1141 of the two balance transformers 113 and 114 are serially connected to the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112, the secondary coils 1132 and 1142 of the two balance transformers 113 and 114 are serially connected to each other to thereby form a loop, and the two balance transformers 113 and 114 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the first exemplary embodiment of the present invention, the two balance transformers 113 and 114 are employed so as to compensate for a shortage of a starting voltage, such that the CCFL 120 may be maintained in a turned on state even if the starting voltage is temporarily insufficient in a portion of the two pairs of the CCFLs 120.
According to the first exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112, designs of the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112 may be substantially similar to each other.
Hereinafter, a second exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
Referring to
The inverter circuit 210 includes one inverter 111, two inverter transformers 112 and 211, four balance transformers 113, 114, 212 and 213 and a current detection transformer 115.
The inverter transformer 211 includes one primary coil 2111 connected to an output terminal of the inverter 111. The inverter transformer 211 and the inverter transformer 112 are connected to the inverter 111 in parallel with each other. In addition, the inverter transformer 211 includes two pairs of secondary coils 2112, 2113, 2114 and 2115 connected to first end portions of two pairs of CCFLs 120. In the two pairs of the secondary coils 2112, 2113, 2114 and 2115 of the inverter transformer 211, an AC high voltage is induced by the primary coil 2111, and the AC high voltage is supplied to the two pairs of CCFLs 120. Second end portions of the two pairs of the CCFL 120 connected to the two pairs of the secondary coils 2112, 2113, 2114 and 2115 are connected to the ground GND.
A primary coil 2121 of the balance transformer 212 is serially connected to the secondary coils 2112 and 2113 of the inverter transformer 211. A primary coil 2131 of the balance transformer 213 is serially connected to the secondary coils 2114 and 2115 of the inverter transformer 211.
Secondary coils 1132, 1142, 2122 and 2132 of the four balance transformers 113, 114, 212 and 213 are serially connected to each other to form a loop. A portion of the loop formed by the secondary coils 1132, 1142, 2122 and 2132 of the four balance transformers 113, 114, 212 and 213 is connected to the ground GND.
A primary coil 1151 of the current detection transformer 115 is serially connected to the secondary coils 1132, 1142, 2122 and 2132 of the four balance transformers 113,114, 212 and 213. A secondary coil 1152 of the current detection transformer 115 is connected between the inverter 111 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the primary coil 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverter 111.
According to the second exemplary embodiment of the present invention, current flowing through the four pairs of the CCFLs 120 is uniformly maintained by an operation of the four balance transformers 113, 114, 212 and 213 since the primary coils 1131, 1141, 2121 and 2131 of the balance transformers are serially connected to the secondary coils 1122, 1123, 1124, 1125, 2112, 2113, 2114 and 2115 of the inverter transformers, the secondary coils 1132, 1142, 2122 and 2132 of the balance transformers 113, 114, 212 and 213, respectively, are serially connected to each other to form a loop, and the four balance transformers 113, 114, 212 and 213 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the second exemplary embodiment of the present invention, the four balance transformers 113, 114, 212 and 213 are employed so as to compensate for a shortage of a starting voltage, such that the CCFL 120 is maintained in a turned on state, even if the starting voltage is temporarily insufficient in a portion of the four pairs of the CCFLs 120.
In addition, according to the second exemplary embodiment of the present invention, since four balance transformers 113, 114, 212 and 213 are employed, the two inverter transformers 112 and 211 connected to each other in parallel may be realized as one inverter.
Further, according to the second exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer may be similar to each other.
Hereinafter, a third exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
Referring to
The inverter circuit 310 includes one inverter 111, three inverter transformers 112, 211 and 311, six balance transformers 113, 114, 212, 213, 312 and 313, and a current detection transformer 115.
The inverter transformer 311 includes one primary coil 3111 connected to an output terminal of the inverter 111. The inverter transformer 311 and the inverter transformers 112 and 211 are connected to the inverter 111 in parallel with each other. In addition, the inverter transformer 311 includes two pairs of secondary coils 3112, 3113, 3114 and 3115 connected to first end portions of two pairs of the CCFLs 120. In the two pairs of the secondary coils 3112, 3113, 3114 and 3115 of the inverter transformer 311, an AC high voltage is induced by the primary coil 3111, and the AC high voltage is supplied to the two pairs of CCFLs 120. Second end portions of the two pairs of the CCFL 120 connected to the two pairs of the secondary coils 3112, 3113, 3114 and 3115 are connected to the ground GND.
A primary coil 3121 of the balance transformer 312 is serially connected to the secondary coils 3112 and 3113 of the inverter transformer 311. A primary coil 3131 of the balance transformer 313 is serially connected to the secondary coils 3114 and 3115 of the inverter transformer 311.
Secondary coils 1132, 1142, 2122, 2132, 3122 and 3132 of six balance transformers 113, 114, 212, 213, 312 and 313 are serially connected to each other to form a loop. A portion of the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122 and 3132 of the six balance transformers 113, 114, 212, 213, 312 and 313 is connected to the ground GND.
A primary coil 1151 of the current detection transformer 115 is serially connected to the secondary coils 1132, 1142, 2122, 2132, 3122 and 3132 of the six balance transformers 113, 114, 212, 213, 312 and 313. A secondary coil 1152 of the current detection transformer 115 is connected between the inverter 111 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the first primary coil 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverter 111.
According to the third exemplary embodiment of the present invention, current flowing through the six pairs of the CCFLs 120 is uniformly maintained by an operation of the six balance transformers 113, 114, 212, 213, 312 and 313 since the primary coils 1131, 1141, 2121, 2131, 3121 and 3131 of the balance transformers 113, 114, 212, 213, 312 and 313 are serially connected to the secondary coils 1122, 1123, 1124, 1125, 2112, 2113, 2114, 2115, 3112, 3113, 3114 and 3115 of the inverter transformers 112, 211 and 311, the secondary coils 1132, 1142, 2122, 2132, 3122 and 3132 of the balance transformers 113, 114, 212, 213, 312 and 313 are serially connected to each other to form a loop, and the six balance transformers 113, 114, 212, 213, 312 and 313 and the portion of the loop which is connected to the ground GND are employed. In addition, according to the third exemplary embodiment of the present invention, six balance transformers 113, 114, 212, 213, 312 and 313 are employed so as to compensate for a shortage of a starting voltage such that the CCFL 120 is maintained in a turned on state, even if the starting voltage is temporarily insufficient in a portion of the six pairs of the CCFLs 120.
Further, according to the third exemplary embodiment of the present invention, since the six balance transformers 113, 114, 212, 213, 312 and 313 are employed, the three inverter transformers 112, 211 and 311, which are connected to each other in parallel, may be operated as one inverter.
In addition, according to the third exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer can be similar to each other.
Hereinafter, the fourth exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
Referring to
The inverter circuit 410 includes one inverter 111, four inverter transformers 112, 211, 311 and 411, eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413, and a current detection transformer 115.
The inverter transformer 411 includes one primary coil 4111 connected to an output terminal of the inverter 111. The inverter transformer 411 and the inverter transformers 112, 211 and 311 are connected to the inverter 111 in parallel with each other. In addition, the inverter transformer 411 includes two pairs of secondary coils 4112, 4113, 4114 and 4115 connected to first end portions of two pairs of the CCFLs 120. In the two pairs of the secondary coils 4112, 4113, 4114 and 4115 of the inverter transformer 411, an AC high voltage is induced by the primary coil 4111, and the AC high voltage is supplied to the two pairs of CCFLs 120. Second end portions of the two pairs of the CCFL 120 connected to the two pairs of the secondary coils 4112, 4113, 4114 and 4115 are connected to the ground GND.
A primary coil 4121 of the balance transformer 412 is serially connected to the secondary coils 4112 and 4113 of the inverter transformer 411. A primary coil 4131 of the balance transformer 413 is serially connected to the secondary coils 4114 and 4115 of the inverter transformer 411.
Secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132 of the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 are serially connected to each other to form a loop. A portion of the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132 of the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 is connected to the ground GND.
A primary coil 1151 of the current detection transformer 115 is serially connected to the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132 of the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413. A secondary coil 1152 of the current detection transformer 115 is connected between the inverter 111 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the first primary 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverter 111.
According to the fourth exemplary embodiment of the present invention, current flowing through the eight pairs of the CCFLs 120 is uniformly maintained by the operation of the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 since the primary coils 1131, 1141, 2121, 2131, 3121, 3131, 4121 and 4131 of the balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 are serially connected to the secondary coils 1122, 1123, 1124, 1125, 2112, 2113, 2114, 2115, 3112, 3113, 3114, 3115, 4112, 4113, 4114 and 4115 of the inverter transformers 112, 211, 311 and 411, the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132 of the balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 are serially connected to each other to form a loop, and the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the fourth exemplary embodiment of the present invention, since eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 are employed, the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 compensate for a shortage of a starting voltage such that the CCFL 120 is maintained in a turned on state even if the starting voltage is temporarily insufficient in a portion of the eight pairs of the CCFLs 120.
Further, according to the fourth exemplary embodiment of the present invention, since the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 are employed, the four inverter transformers 112, 211, 311, and 411, which are connected to each other in parallel, may be operated as one inverter.
In addition, according to the fourth exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer may be substantially similar to each other.
Hereinafter, a fifth exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
Referring to
The inverter circuit 510 includes two inverters 111 and 511, two inverter transformers 512 and 513, two balance transformers 113 and 114 and a current detection transformer 115.
The inverter 111 controls an output signal based on a current detection value fedback from the current detection transformer 115. The inverter transformer 512 includes one primary coil 5121 connected to an output terminal of the inverter 111. In addition, the inverter transformer 512 includes one pair of secondary coils 5122 and 5123 connected to first end portions of one pair of the CCFLs 120. In the one pair of the secondary coils 5122 and 5123 of the inverter transformer 512, an AC high voltage is induced by the primary coil 5121, and the AC high voltage is supplied to the one pair of the CCFLs 120. Second end portions of the one pair of the CCFLs 120 are connected to the ground GND.
The inverter 511 includes the same structure as that of the inverter 111. The inverter 511 controls an output signal based on a current detection value fedback from the current detection transformer 115. The inverter transformer 513 includes one primary coil 5131 connected to an output terminal of the inverter 511. In addition, the inverter transformer 513 includes one pair of secondary coils 5132 and 5133 connected to first end portions of one pair of CCFLs 120. In the one pair of the secondary coils 5132 and 5133 of the inverter transformer 513, an AC high voltage is induced by the primary coil 5131, and the AC high voltage is supplied to the one pair of the CCFLs 120. Second end portions of the one pair of the CCFL 120 are connected to the ground GND.
A primary coil 1131 of the balance transformer 113 is serially connected to the secondary coils 5122 and 5123 of the inverter transformer 512. A primary coil 1141 of the balance transformer 114 is serially connected to the secondary coils 5132 and 5133 of the inverter transformer 513.
Secondary coils 1132 and 1142 of the two balance transformers 113 and 114 are serially connected to each other to form a loop. A portion of the loop formed by the secondary coils 1132 and 1142 of the two balance transformers 113 and 114 is connected to the ground GND.
A primary coil 1151 of the current detection transformer 115 is serially connected to the secondary coils 1132 and 1142 of the two balance transformers 113 and 114. A secondary coil 1152 of the current detection transformer 115 is connected between the inverters 111 and 511 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the first primary 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverters 111 and 511. The inverter 511 performs substantially the same operation as that of the inverter 111.
In other words, the inverter 511 controls an AC voltage of an output signal based on the current detection value fedback from the current detection transformer 115 so as to supply a proper AC voltage to the primary coil 5131 of the inverter transformer 513.
According to the fifth exemplary embodiment of the present invention, current flowing through two pairs of the CCFLs 120 is uniformly maintained by an operation of the two balance transformers 113 and 114 since the primary coils 1131 and 1141 of the balance transformers 113 and 114 are serially connected to the secondary coils 5122, 5123, 5132 and 5133 of the inverter transformers 512 and 513, the secondary coils 1132 and 1142 of the balance transformers are serially connected to each other to form a loop, and the two balance transformers 113 and 114 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the fifth exemplary embodiment of the present invention, since the two balance transformers 113 and 114 are employed, the two balance transformers 113 and 114 compensate for a shortage of a starting voltage such that a CCFL 120 is maintained in a turned on state even if the starting voltage is temporarily insufficient in a portion of two pairs of the CCFLs 120.
In addition, according to the fifth exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer can be similar to each other.
Hereinafter, a sixth exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Referring to
The inverter circuit 610 includes two inverters 111 and 511, two inverter transformers 112 and 211, four balance transformers 113, 114, 212 and 213, and a current detection transformer 115.
The inverter transformer 112 includes one primary coil 1121 connected to an output terminal of the inverter 111. The inverter transformer 112 includes two pairs of secondary coils 1122, 1123, 1124 and 1125 connected to first end portions of two pairs of the cathode ray tubes 120. The two pairs of the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112 provide an AC high voltage, which is induced by the primary coil 1121, to the two pairs of the CCFLs 120. Second end portions of the two pairs of the CCFLs 120 connected to the two pairs of the secondary coils 1122, 1123, 1124 and 1125 are connected to the ground GND.
The inverter transformer 211 includes one primary coil 2111 connected to an output terminal of the inverter 511. The inverter transformer 211 includes two pairs of secondary coils 2112, 2113, 2114 and 2115 connected to first end portions of two pairs of the CCFLs 120. The two pairs of the secondary coils 2112, 2113, 2114 and 2115 of the inverter transformer 211 provide an AC high voltage, which is induced by the primary coil 2111, to the two pairs of the CCFLs 120. Second end portions of the two pairs of the cathode ray tubes 120 connected to the two pairs of the secondary coils 2112, 2113, 2114 and 2115 are connected to the ground GND.
A primary coil 1131 of the balance transformer 113 is serially connected to the secondary coils 1122 and 1123 of the inverter transformer 112, and a primary coil 1141 of the balance transformer 114 is serially connected to the secondary coils 1124 and 1125 of the inverter transformer 112.
A primary coil 2121 of the balance transformer 212 is serially connected to the secondary coils 2112 and 2113 of the inverter transformer 211, and a primary coil 2131 of the balance transformer 213 is serially connected to the secondary coils 2114 and 2115 of the inverter transformer 211.
Secondary coils 1132, 1142, 2122 and 2132 of the four balance transformers 113, 114, 212 and 213 are serially connected to each other to form a loop. A portion of the loop formed by the secondary coils 1132, 1142, 2122 and 2132 of the four balance transformer 113, 114, 212 and 213 is connected to the ground GND.
A primary coil 1151 of the current detection transformer 115 is serially connected to the secondary coils 1132, 1142, 2122 and 2132 of the four balance transformers 113, 114, 212 and 213. A secondary coil 1152 of the current detection transformer 115 is connected between the inverters 111 and 511 and the ground GND. In the secondary coil 1152 of the current detection transformer 115, a value of current induced by the first primary 1151 of the current detection transformer 115 is transformed into a current detection value which is provided to the inverters 111 and 511.
According to the sixth exemplary embodiment of the present invention, current flowing through four pairs of the CCFLs 120 is uniformly maintained by an operation of the four balance transformers 113, 114, 212 and 213 since the primary coils 1131, 1141, 2121 and 2131 of the balance transformers 113, 114, 212 and 213 are serially connected to the secondary coils 1122, 1123, 1124, 1125, 2112, 2113, 2114 and 2115 of the inverter transformers 112 an 211, the secondary coils 1132, 1142, 2122 and 2132 of the balance transformers are serially connected to each other to form a loop, and the four balance transforms 113, 114, 212 and 213 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the sixth exemplary embodiment of the present invention, the four balance transformers 113, 114, 212 and 213 are employed so as to compensate for a shortage of a starting voltage, such that a CCFL 120 is maintained in a turned on state even if the starting voltage is temporarily insufficient in a portion of two pairs of the CCFLs 120.
In addition, according to the sixth exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, details of the secondary coils of the inverter transformer can be similar to each other.
Hereinafter, a seventh exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Referring to
The inverter circuit 710 includes two inverters 111 and 511, four inverter transformers 112, 211, 311 and 411, eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413, and a current detection transformer 115.
According to the seventh exemplary embodiment of the present invention, the two inverters 111 and 511, two inverter transformers 112 and 211 connected to an output terminal of the inverter 111 in parallel and two inverter transformers 311 and 411 connected to the inverter 511 in parallel may be provided. The structure of the backlight assembly 700 according to the seventh exemplary embodiment is substantially the same as that of the fourth exemplary embodiment, except for the above mentioned elements.
The inverter 511 controls an AC voltage of an output signal based on a detected current fedback from the current detection transformer 115 so as to supply a proper AC voltage to the primary coils 3111 and 4111 of the inverter transformers 311 and 411. An operation of the backlight assembly 700 according to the seventh exemplary embodiment of the present invention is substantially similar to that of the fourth exemplary embodiment, except for the above mentioned operation of the inverter 511.
According to the seventh exemplary embodiment of the present invention, current flowing through eight pairs of the CCFLs 120 is uniformly maintained by an operation of the eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413 since the primary coils of the balance transformers are serially connected to the secondary coils of the inverter transformers, the secondary coils of the balance transformers are serially connected to each other while forming a loop, and the eight balance transforms 113, 114, 212, 213, 312, 313, 412 and 413 and the portion of the loop which is connected to the ground GND are employed.
In addition, according to the seventh exemplary embodiment of the present invention, the eight balance transformers 113, 114, 212, 213, 312, 313412, and 413 are employed so as to compensate for a shortage of a starting voltage, such that a CCFL 120 is maintained in a turned on state even if the starting voltage is temporarily insufficient in a portion of the eight pairs of the CCFLs 120.
In addition, according to the seventh exemplary embodiment of the present invention, since current detection interconnections are unnecessary for the secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer can be similar to each other.
In exemplary embodiments of the present invention, the two inverters 111 and 511, three or four inverter transformers connected to the output terminal of the inverter 111 in parallel (see,
Hereinafter, an eighth exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
Referring to
The inverter circuit 810 includes one inverter 111, four inverter transformers 112, 211, 311 and 411, eight balance transformers 113, 114, 212, 213, 312, 313, 412 and 413, a current detection transformer 115 and a fault detection assembly 820. In other words, the inverter circuit 810 includes the fault detection assembly 820 in addition to the inverter circuit 410 according to the fourth exemplary embodiment of the present invention.
The fault detection assembly 820 detects a high voltage discharge such as a corona discharge and an arc discharge occurring due to a defect of an insulating material between a high voltage unit and the ground GND in the inverter circuit 110.
The fault detection assembly 820 detects the fault of the insulating material referring to current flowing through a plurality of balance transformers 113, 114, 212, 213, 312, 313, 412 and 413.
The fault detection assembly 820 includes a plurality of tertiary coils 811, 812, 813, 814, 815, 816, 817 and 818 positioned in the balance transformers 113, 114, 212, 213, 312, 313, 412 and 413, and diodes 821, 822, 823 and 824, a fault detector 825 and a notification unit 826.
In order to offset AC voltages generated from neighboring tertiary coils from each other, a pair of neighboring tertiary coils among the plurality of tertiary coils is serially connected to each other, and one end portion of the connection body of the pair of neighboring tertiary coils is linked with the loop formed by the secondary coils.
In other words, a pair of the neighboring tertiary coils 811 and 812 is serially connected to each other such that AC voltages generated from the neighboring tertiary coils 811 and 812 are offset from each other, and one end portion of the connection body of the neighboring tertiary coils 811 and 812 is linked with the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132.
Further, a pair of the neighboring tertiary coils 813 and 814 is serially connected to each other such that AC voltages generated from the neighboring tertiary coils 813 and 814 are offset from each other, and one end portion of the connection body of the neighboring tertiary coils 813 and 814 is linked with the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132.
In addition, a pair of the neighboring tertiary coils 815 and 816 is serially connected to each other such that AC voltages generated from the neighboring tertiary coils 815 and 816 are offset from each other, and one end portion of the connection body of the neighboring tertiary coils 815 and 816 is linked with the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132.
In addition, a pair of the neighboring tertiary coils 817 and 818 is serially connected to each other such that AC voltages generated from the neighboring tertiary coils 817 and 818 are offset from each other, and one end portion of the connection body of the neighboring tertiary coils 817 and 818 is linked with the loop formed by the secondary coils 1132, 1142, 2122, 2132, 3122, 3132, 4122 and 4132.
The diodes 821, 822, 823 and 824 include input terminals connected to one end portion of the connection body of the paired neighboring tertiary coils, and detect current flowing through the connection body in order to create a current detection value.
In other words, the diode 821 includes an input terminal connected to one end portion of the connection body of the neighboring tertiary coils 811 and 812, and detects a current flowing through the connection body in order to create a current detection value.
In addition, the diode 822 includes an input terminal connected to one end portion of the connection body of the paired neighboring tertiary coils 813 and 814, and detects a current flowing through the connection body in order to create a current detection value.
In addition, the diode 823 includes an input terminal connected to one end portion of the connection body of the paired neighboring tertiary coils 815 and 816, and detects a current flowing through the connection body in order to create a current detection value.
In addition, the diode 824 includes an input terminal connected to one end portion of the connection body of the paired neighboring tertiary coils 817 and 818, and detects a current flowing through the connection body in order to create a current detection value.
The fault detector 825 is connected to output terminals of the diodes 821, 822, 823 and 824 in order to compare the current detection value through the diodes 821, 822, 823, or 824 or a voltage detection value, into which the current detection value is converted, with a predetermined reference value. Then, the fault detector 825 determines a fault state to create the determination result.
As an example, the fault detector 825 will be described below with reference to
Referring to
An input terminal of the current-voltage converter 8251 is connected to the output terminals of the diodes 821, 822, 823 and 824. An output terminal of the current-voltage converter 8251 is connected to a first input terminal of the comparator 8253. An output terminal of the reference voltage generator 8252 is connected to a second input terminal of the comparator 8253. An output terminal of the comparator 8253 is connected to an input terminal of the notification unit 826.
The current-voltage converter 8251 converts a current detection value output from the diode 821, 822, 823 and 824 into a voltage detection value to provide the voltage detection value to the comparator 8253. The reference voltage generator 8252 generates reference voltage to supply the reference voltage to the comparator 8253. The comparator 8253 compares the voltage detection value from the current-voltage converter 8251 with the value of the reference voltage of the reference voltage generator 8252 to provide a comparison result to the notification unit 826. The notification unit 826 notifies the comparison result output from the comparator 8253. For example, the notification unit 826 displays the comparison result on a display (not shown).
In addition, according to the eighth exemplary embodiment of the present invention, the fault detection assembly 820 may detect and notify a fault in addition to other effects of the exemplary embodiments.
Further, the fault detection assembly 820 may be added to the structure of the other exemplary embodiments with exception to the fourth exemplary embodiment.
Hereinafter, a ninth exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings.
The inverter circuit and the backlight assembly include substantially the same structure as that of the first exemplary embodiment of the present invention.
Referring to
Further, balance-transformer-connection pins 1122b, 1123b, 1124b and 1125b for the two pairs of the secondary coils 1122, 1123, 1124 and 1125 of the inverter transformer 112 are arranged at an opposite side of the first connection pins 1122a, 1123a, 1124a and 1125a of the inverter transformer 112 in order to connect to a plurality of balance transformers 113 and 114. In addition, inverter-connection pins 1121a and 1121b for a primary coil 1121 of the inverter transformer 112 are arranged at an opposite side of the first connection pins 1122a, 1123a, 1124a and 1125a of the inverter transformer 112 in order to connect to the inverter 111.
In addition, the ninth exemplary embodiment of the present invention is adaptable for other exemplary embodiments with exception to the first exemplary embodiment.
As described above, according to the ninth exemplary embodiment of the present invention, since the balance-transformer-connection pins are arranged at an opposite side of the discharge-tube-connection pins of the inverter transformer, the balance-transformer connection pins are protected from the influence of a high voltage applied to the discharge-tube connection pins.
According to the present invention, since current flowing through the plurality of pairs of discharge tubes is uniformly maintained due to an operation of a plurality of balance transformers such that the balance transformers compensate for a shortage of a starting voltage even if the starting voltage is insufficient in a portion of the two pairs of the CCFLs. Accordingly, portions of CCFLs are prevented from being turned off. In addition, since current detection interconnections are unnecessary for secondary coils of the inverter transformer, designs of the secondary coils of the inverter transformer can be similar to each other. Further, a fault can be detected and notified. The connection pins for balance transformers can be protected from an influence of the high voltage applied to connection pins for discharge tubes.
Although some exemplary embodiments of the present invention have been described, it is understood that the present invention should not be limited to these exemplary embodiments but various changes and modifications can be made by one of ordinary skill in the art within the spirit and scope of the present invention as hereinafter claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0086971 | Sep 2006 | KR | national |
