TWI263460B - Backlight including external electrode fluorescent lamp and method for driving the same - Google Patents

Abstract

The present invention discloses a backlight including external electrode fluorescent lamps and a method for driving the backlight. The backlight includes fluorescent lamps having external electrodes made of an electrically conductive material for wrapping outer peripheral surfaces including edge cross-sections on both ends of a glass tube with a layer of fluorescent substance applied thereon. The backlight is constructed in a manner that a plurality of such fluorescent lamps are installed at outer portions of a plastic light guide; that an alternating current type power source is applied from the outside to the fluorescent lamps by installing a plurality of the fluorescent lamps between a reflecting plate and a diffusing plate and electrically connecting them with one another; or that the fluorescent lamps are installed at a predetermined interval between upper and lower substrates with a layer of fluorescent substance applied thereon and spaced from each other, and electrodes to which an alternating current type power source is applied from outside are formed on opposite outer or inner faces of the assembled upper and lower substrates. According to the present invention, since the electrodes of the fluorescent lamps are formed at external portions and are repeatedly disposed, the fluorescent lamps can be interconnected in parallel to and driven by a single power source. Further, since the fluorescent lamps serve as a partition and simultaneously emit light by themselves, their uniform luminance can be maintained and thinner backlight can be obtained. The backlight of the present invention is driven by a square wave from a switching inverter, and is characterized by the use of an overshooting waveform and a self-discharge effect favorable to an initial discharge, thereby driving it by a low frequency of several dozen kHz and thus realizing high luminance and high efficiency.

Description

1263460 A7 ---B7___ V. INSTRUCTION DESCRIPTION (I) Field of the Invention The present invention relates to a backlight source comprising an external electrode fluorescent lamp and a method for driving the backlight source, and more particularly, It is about the external electrode which is mounted on both ends of the electrodeless fluorescent lamp, and a switching converter applies a square wave AC voltage having a frequency of 100 kHz or lower to the external electrode including the external electrode fluorescent lamp A backlight and a method for driving the backlight. BACKGROUND OF THE INVENTION Generally, a flat panel display is classified as an active illuminating type or a passive illuminating type. The active light-emitting type includes a flat cathode ray tube, a plasma display panel, an electronic active light-emitting element, a fluorescent display, a light-emitting diode, and the like. The passive illumination type includes a liquid crystal display. In a passive light-emitting flat panel display such as a liquid crystal display, image formation is not caused by self-illumination but by light from the outside of the liquid crystal display panel. In order to solve the above problem, the backlight is placed on the back of the liquid crystal display panel so that the display can emit light. As a result, the image formed on the liquid crystal display can be seen even in a dark environment. General requirements for backlights include high brightness, high efficiency, uniform brightness, long life, thinness, light weight, low price, and the like. For the case of a notebook computer, high efficiency and long life are required in order to reduce the power consumption, and in the case of a monitor and a television, high brightness is required. A type of cold cathode fluorescent lamp (CCFL) and a flat fluorescent lamp on which upper and lower substrates are coated with a fluorescent substance are widely used. ____ 4 P-sheet scale is applicable to the Chinese National Standard (CNS). A4 size (210 X 297 mm) """ - (Please read the note on the back and fill out this page)

---I----订---------- 1263460 Δ7 Α7 ___ Β7___ V. Description of invention (>) is the backlight source. The cold cathode fluorescent lamp can be classified according to the arrangement of the light source with respect to the display surface (1) the edge light pattern using the plastic optical waveguide, and (H) the direct light pattern in which the repeated light source is disposed on the plane. However, according to the conventional technique, the cold cathode fluorescent lamp operates at a high brightness of about 30,000 cd/m2, and as a result, there is a problem of lamp life. In particular, the edge light type is not suitable for large screen panels because the brightness of the display panel is too low, even if the brightness of the cold cathode fluorescent lamp itself is high. In the direct light pattern, it is impossible to drive the cold cathode fluorescent lamps in parallel with a conventional inverter, and because of the cold cathode firefly arranged on the plane in order to maintain the optimum brightness of the display panel. The number of light lamps is limited, so that the arrangement of the cold cathode fluorescent lamps is large. As a result, a reflector with a special configuration is required. At the same time, the thickness of the display panel is added to the distance between the diffuser plate and the lamp required to obtain uniform brightness. In the form of flat fluorescent lamps, sufficient thickness is required to avoid damage to the glass substrate because the pressure between the combined upper and lower substrates is lower than atmospheric pressure. The result is that there is a disadvantage in that the weight of the lamp increases. Further, in the case of a flat fluorescent lamp, a beaded or cross-shaped partition and spacer member is placed between the upper and lower substrates to enlarge the area of the screen. Therefore, the problem of an increase in weight due to an increase in the thickness of the substrate and the problem of heat generation due to inefficiency become more serious. In the case where the partition member is used, since the strip shape of the partition member is displayed on the screen, uniform brightness cannot be guaranteed. According to the above, it is necessary to develop a backlight source that is capable of being lightly made while ensuring high brightness and high efficiency of a liquid crystal display screen having an increasing size. 5 ^ Paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) -- (Please read the back note and fill out this page) 0 - Line - A7 1263460 ___B7___ V. Invention Description (,) Tradition The electrode structure of the external electrode fluorescent lamp (EEFL) includes a belt type; the metal capsule is connected to the glass tube type; the space at both ends of the glass tube is expanded and bulged type (Fig. 11). Although the external electrode fluorescent lamp has a longer life than the cold cathode fluorescent lamp, since the external electrode fluorescent lamp is driven by a high frequency of several MHz, high brightness can be obtained, and due to high frequency electromagnetic interference, Low cross female; large size power supply, etc., it is not widely used as the source of the source. In addition, when an inductor-capacitor type inverter is used to drive the external electrode fluorescent lamp, the external electrode fluorescent lamp is not used as a light source for the backlight because of its low brightness and low efficiency. Figure 11 shows the configuration of a conventional external electrode fluorescent lamp as a comparison with the configuration of the present invention. Figure 11 (a) is a strip-type outer electrode featuring a plurality of 'band-type electrodes mounted on a cylinder of a glass tube, and in that it reduces the length of each strip-type electrode and uses a high frequency sea of several MHz&> i drives it. The belt type outer electrode fluorescent lamp of Fig. 11(a) has an advantage that the additional electrodes are mounted even in the middle portion of the glass tube because they are mounted on the cylinder of the glass tube. Recently, a backlight source is constructed by directly arranging a belt type electrode fluorescent lamp on a reflector. Connection 1 The external electrode fluorescent lamp is driven by a high frequency of several MHz, and is derived to obtain a high brightness of several 10,000 cd/m2. In the case of an elongated glass tube, the ~-loaded electrode is helpful for such a high _ rate on the middle portion of the glass tube. However, there is a problem that the display panel is not uniform because the brightness of the electrode portion is reduced. # In addition, high frequency drives basically cause electromagnetic interference, low electrode efficiency, high frequency power supply can not be miniaturized, and so on. The previous ___6_ this & scale applies to the Chinese National Standard (CNS) A4 specification (21〇 297 297 mm) one, _ (please read the notes on the back and fill out this page)

i line. A7 1263460 __B7______ V. Description of invention (work) The problem is disclosed in Japanese Patent Publication No. (Showa) 60_25488 (February 13, 1985), Korean Patent Application No. 1〇-1999_〇〇52964, and Japan Patent Application No. 98-336936 (November 27, 1998). Figure 11 (b) is an external electrode type in which metal capsules are attached to both ends of a glass tube, characterized in that a ferroelectric body is coated on the inner side of the metal capsule. This type is disclosed in U.S. Patent No. 2,624,858 (June 6, 1953). Figure 11 (b) This type is used in the case of large diameter glass tubes. That is to say, when the glass tube is very thick, this type can be used because of the voltage drop of the glass tube itself. However, since the coefficient of thermal expansion of the glass tube and the metal is different, the joint portion of the electrode is easily broken. However, in the case of a thin glass tube, like a cold cathode ray tube widely used for the current backlight, the outer diameter is 2.6 mm and the thickness is less than 0.5 mm, and it is not necessary to use the type in which the metal capsule is attached to the glass tube because The capacitance drop of the glass tube itself is very small. Fig. 11 (c) and (d) show the lamp tube in which the ends of the glass tube are larger than the middle portion in order to achieve high brightness and high efficiency. It was revealed in US Patent Nos. 1,612,387 (November 28, 1926) and 1,676,790 (July 10, 1928). When the space between the ends of the glass tube expands as described above, the brightness and efficiency of the tube increase, but this structure is difficult to use on the thin tube. As for the application of a square wave alternating current voltage having a frequency of 100 kHz or lower by means of a switching converter according to the invention, it is provided with a plurality of different types of external electrodes, which comprise a basic version of the end-covered electrode 'having The ends of the sealed fine glass tube with a diameter of several millimeters are covered with end-capped type ___7__ This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 x 297 mm) (please read the notes on the back and fill in the form) This page)

Order line A7 1263460 ___ET__ V. Invention description (s) Extreme coverage. The end-covered electrode covering the cylindrical surface at both ends of the glass tube plus the edge surface has more advantages than the strip-shaped electrode covering only the cylindrical surface because it can achieve higher brightness and efficiency. According to the test results of the applicant of the present application, when the length of the electrode is increased in the direction of the glass tube, high brightness can be obtained. However, as the length of the electrode increases, the effective illuminating surface is reduced. As a result, when such an electrode is used in a backlight, the area where the edge of the display panel does not emit light is increased because the portion of the electrode is large. According to the above, the end cover type has more advantages than the strip type electrode from the viewpoint that the electrode can be shortened. Further, particularly in the fluorescent lamp according to the present invention, the strip-shaped electrode does not need to be formed in the longitudinal portion of the glass tube. At present, it is difficult to use the expansion type of the glass tube at both ends due to the method of manufacturing the thin tube. In the fluorescent lamp according to the present invention, the electrode lengths at both ends of the glass tube are first appropriately selected. When the end-covering electrode is used as a light source, whether it is an edge light type or a direct light type backlight source, the electrode maintains a sufficient length by bending both ends of the glass tube (different from the straight metal capsule type) To minimize the area where the edges do not emit light. In this way, high brightness and high efficiency of the electrode can be obtained. In another aspect, the present invention provides a driving method for a backlight source using an external electrode fluorescent lamp, and more particularly to provide a uniform high brightness and high efficiency driving circuit for achieving a large area of the backlight. A technique for driving a cold cathode fluorescent lamp widely used for a conventional backlight source is disclosed in Korean Patent Laid-Open Publication No. 1998-028921. Figure 12 is a circuit diagram of the prior art showing an integrated circuit for a cold cathode fluorescent lamp for driving a display panel of a liquid crystal display. The figure also shows that the paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page) 0. --Line · 1263460 a7 __________ B7 __ V. DESCRIPTION OF THE INVENTION () (Please read the precautions on the back and fill out this page) The peripheral circuit system is shown, including a lamp-driven integrated circuit 100 with multiple pins, and a main power supply with a half-bridge circuit. Circuit portion 120, and a tube 14". The lamp driving integrated circuit 100 includes a first pin 1 connected to the input voltage terminal and a second pin 2 connected to a predetermined minimum frequency, and is connected to the third pin 3 of a predetermined maximum frequency. The fourth pin 4 of the ground voltage terminal is connected to the fifth pin 5 of the feedback ground terminal, and is connected to the sixth pin 6 of the predetermined comparison end point, and is connected to the seventh connection of the predetermined internal high voltage end point. The pin 7' and the eighth pin 8 which is predetermined to determine the end point of the external control signal of the integrated circuit switch. Further, the main power supply circuit portion 120 includes a half bridge circuit for reacting the output signals of the predetermined pins on the lamp driving integrated circuit 100, and a plurality of passive components. Lamp 140 is fabricated to be driven in response to a predetermined output signal to main power circuit portion 120. The voltage applied to a cold cathode fluorescent lamp generally used for an LCD backlight has a sinusoidal pattern. Taking the cold cathode fluorescent lamp in the above example as an example, the high voltage required for initializing and maintaining the discharge of the cold cathode fluorescent lamp is obtained from a low alternating voltage of several tens of kHz, which can be used. The inductor-capacitor resonant converter of the step-up transformer is obtained. Such an inductive capacitive resonance type converter has the advantages of simple device and high efficiency. However, although the cold cathode fluorescent lamps are connected in parallel with each other, it is impossible to drive them by a single inverter. Therefore, whether it is a direct light type backlight or a plastic optical waveguide combined with a cold cathode fluorescent lamp type, the commutation ____9__ This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) ' ' 1263460 A7 B7 Explain that the number of devices must be equal to the number of cold cathode fluorescent lamps. On the other hand, a plurality of external electrode fluorescent lamps connected in parallel with each other can be driven by a single inverter. The reason is as follows: since the external electrode fluorescent lamp electrode is not exposed to the discharge space, but is placed outside the glass tube, the real current does not flow to the electrode, and the wall charge is collected at the electrode portions at both ends. The discharge at both ends of the lamp is interrupted by the reverse voltage caused by the wall charge. Then, the other tube is discharged, and likewise other wall charges are formed, so that the other tubes are sequentially discharged. In this way, a plurality of lamps can be illuminated with a single inverter. However, in the case of using an inverter for outputting a sine wave of a cold cathode fluorescent lamp to drive an external electrode fluorescent lamp, since wall charges cannot be efficiently controlled, it produces relatively low brightness and efficiency. . In addition, when many external electrode fluorescent lamps are alternately connected in parallel and driven by such an inverter, the period during which a high voltage is applied in one cycle is limited, and the number of actively emitting external electrode fluorescent lamps is limited. It is limited. Thus, in the case where some of the external electrode fluorescent lamps are arranged on the plane of the backlight, uniform brightness cannot be achieved. As described above, even if the external electrode fluorescent lamp can be driven by an inductor-capacitor resonant type inverter having a tens of kHz with respect to driving the cold cathode fluorescent lamp, the external electrode fluorescent lamp is efficiently used. The backlight is still not achievable. In addition, if the external electrode fluorescent lamp is driven at a high frequency of several MHz by a conventional method, electromagnetic interference, low efficiency, and miniaturization of the power source cannot be easily solved. Summary of the Invention ___ _10 ___ This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page)

i line - 1263460 A7 __B7 V. Description of the invention (X') The present invention has been carefully considered to solve the above problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight source in which a glass tube formed with an external electrode is disposed outside the plastic optical waveguide or on a reflective plate and has a frequency of 1 〇〇 kHz or lower. A wave alternating voltage is applied to the electrodes, thereby providing a driving method for achieving a uniform, high brightness, and high efficiency backlight of the backlight. These fluorescent lamps are generally driven using an inductor-capacitor resonant converter. However, the present invention enables the external electrode fluorescent lamp to be driven by a switching converter circuit that outputs a square wave AC pulse, and therefore, the present invention is compared with a driving method using an inductor-capacitor resonant type converter, at least Double the brightness and efficiency. In other words, for a single-tube external electrode fluorescent lamp, the outer diameter is 2.6 mm and is often used in the backlight of the liquid crystal display, reaching several 1〇, 売cd/m2 and 50 lm /W or more efficient. In particular, according to the test results of the applicant of the present invention, the electrode fluorescent lamp of the present invention has a higher efficiency than the cold cathode fluorescent lamp at a luminance point of about 10,000 d/m2. Therefore, based on the foregoing characteristics, if the external electrode fluorescent lamp can operate at a higher efficiency brightness operating point, it becomes a good source of backlight. Unlike cold cathode fluorescent lamps, the present invention has the additional advantage that the lamp has a long life, the electrodeless lamp can be easily fabricated, and when many of the outer electrode fluorescent lamps are alternately connected in parallel, the lamps can be A single inverter is used to drive. Similar to cold cathode fluorescent lamps, external electrode fluorescent lamps can also be used in edge light mode and direct light mode in the present invention. Another object of the present invention is to provide a backlight source using a plurality of fluorescent lamps, the _π_ paper scale is applicable to the Chinese National Standard (CNS) A4 specification (21 〇 X 297 mm) (please read the back first) Note on this page)

Line A7 1263460 __ B7___ V. Description of the Invention (1) By arranging a plurality of fluorescent lamps having an external electrode between the upper and lower substrates having the phosphor layer thereon. The present invention has been carefully considered to solve the problem of driving a backlight source using the aforementioned fluorescent lamp and driving a large backlight source formed on a flat surface. Another object of the present invention is to provide a uniform and high brightness and high efficiency backlight driving method capable of achieving a large area of a backlight made by arranging a plurality of external electrode fluorescent lamps. In order to achieve the above objects, the present invention provides a backlight comprising a fluorescent lamp, the fluorescent lamp comprising a glass tube into which a discharge gas is injected, and a layer of phosphor is applied to the glass tube. Around the inner tube wall, and the ends of the rear glass tube are tightly sealed; and are configured to have a linear shape, an L shape, a C shape, a spiral shape, or a wave shape, and are used to cover the glass tubes An end capping type outer electrode; and a switching inverter connected to the outer electrodes for applying a square wave alternating voltage having a frequency of 100 kHz or lower to the outer electrodes. In addition, the present invention provides a backlight source comprising an upper substrate, an upper layer of phosphor material applied to the bottom surface of the upper substrate; and a lower substrate having a lower layer of phosphor material applied to the substrate a top surface of the lower substrate is mounted opposite the upper substrate; an edge support frame is inserted between the upper and lower substrates to tightly seal the upper and lower substrates; the outer electrode fluorescent lamp is pre-wired The determined spacing is mounted above the lower substrate and comprises a glass tube into which a discharge gas is injected, and a layer of phosphor material is applied around the inner tube wall of the glass tubes, and the ends of the glass tubes are then closely Sealed __12_____ This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page)

1263460 A7 ___B7____ V. Inventive Note (), and an end-covering type external electrode for covering both ends of the glass tubes; a discharge gas which is injected into an internal space when the upper and lower substrates are sealed; a plurality of electrodes formed on the outer side surfaces of the combined upper and lower substrates, respectively, connected to the electrode connection line to which the alternating current power source is applied; and a switching inverter connected to the electrodes For applying a square wave AC voltage having a frequency of 100 kHz or lower to the electrodes. Furthermore, the present invention provides a method for driving a backlight having a plurality of external electrode fluorescent lamps, the steps of which include dividing a plurality of external electrode fluorescent lamps into a plurality of predetermined regions; The connecting wires are respectively connected to some external electrodes of the electrode fluorescent lamps located outside the individual divided regions; some switching converters are respectively connected to the electrode connecting wires connected to the individual divided regions; applying the same gate signal to each a switching converter; and in response to the gate signal, simultaneously supplying an in-phase square wave AC voltage having a frequency of 100 kHz or lower to the external electrode fluorescent lamps from the switching converters. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and features of the invention will be apparent from the A perspective view of an end-covered external electrode fluorescent lamp. Figure lb is a partial perspective view of a curved external electrode fluorescent lamp according to another example of the present invention. Figure 2 shows the backlight according to the first embodiment of the present invention ______13 This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 public)' *------- (please Read the notes on the back and fill out this page. -II II I 1 BOOK----- II--*5^ · A7 1263460 ___B7____ V. INSTRUCTIONS (“丨) Some schematic diagrams of the arrangement used by the source, Wherein the external electrode fluorescent lamp is arranged in an edge region of the plastic optical waveguide. Fig. 3a is a schematic view showing a linear end-covering type fluorescent light of a direct light type backlight source according to a second embodiment of the present invention. Figure 3b is a schematic diagram of a curved electrode type fluorescent lamp of a direct light type backlight according to a second embodiment of the present invention. Figure 3c is a schematic view. Another mode of bending electrode type fluorescent lamp according to the direct light type backlight of the second embodiment of the present invention is shown. Fig. 3d is a schematic view showing a second embodiment according to the present invention. Bending of a direct light type backlight Figure 3e is a schematic view showing the connection of an overlapping capsule structure of a direct light type backlight according to a second embodiment of the present invention. Figure 3f is a diagram BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is a view showing a second embodiment of a direct light type backlight source for use in a large-area screen according to a second embodiment of the present invention. FIG. An exploded perspective view of a direct light type backlight source. Figure 5 shows some schematic views showing the reflectors and fluorescent lamps of some direct light type backlights according to a second embodiment of the present invention. _______ 14 This paper size is applicable to China National Standard (CNS) A4^T^10 X 297 mm)--- (Please read the notes on the back and fill out this page) Order · · i line · A7 1263460 n___E_____ V. Invention Figure 6a is an exploded perspective view showing a state before the combination of the illuminant-divided backlights according to the third embodiment of the present invention. Figure 6b is a partially cut away The perspective view is shown to show the state of the combination of the backlights of Fig. 6a. Fig. 6c is a diagram of the singularity used to separate the illuminators according to the third embodiment of the present invention. Connection of some electrodeless fluorescent lamps between the substrates of the type of backlight source and some internal slot type multi-capsule electrodes. FIG. 7 is a schematic diagram showing a switching according to an embodiment of the present invention. The streamer, and the signal waveform applied to the gate of the inverter. Fig. 8 is a schematic diagram showing that the signal waveform outputted by the switching converter according to an embodiment of the present invention is discharged at the discharge. Changes before and after the start. Fig. 9 is a schematic view showing a square wave driven self-discharge phenomenon according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an in-phase separation drive for a large-area backlight according to another embodiment of the present invention. Figure 11 shows some schematic views of a conventional external electrode fluorescent lamp. Figure 12 is a circuit diagram showing a cold cathode fluorescent lamp driving integrated circuit for a conventional liquid crystal display panel and its peripheral circuits. Explanation of the symbols of the Meng symbol 10 · Fluorescent lamp ^^ Scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 public) ' " - (Please read the note on the back and fill in this page)

Order·Line·A7 1263460 V. Invention (θ) 11 · Glass tube 12 · Fluorescent substance 13 · External electrode 20 · Back light source 21 · Reflector 22 · Fluorescent lamp 23 · Outer electrode 23a • Outermost Outer electrode 24 · Electrode connection line 25 · Diffuser plate 30 · Back light source 31 · Upper substrate 32 · Lower substrate 33 · Upper layer phosphor 34 · Lower layer phosphor 35 · Fluorescent lamp 36 · External electrode 37 · Upper electrode 38 · Lower electrode 39 · Edge support frame 300 - Electrode connection line DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a fluorescent lamp according to an example of the present invention, and a backlight using the fluorescent lamp, Will refer to some accompanying (please read the notes on the back and fill out this page)

This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) A7 1263460 B7 - - ..... ' " One "" ' V. Invention Description (, V) Graphic is detailed Explanation. Fig. 1 shows a fluorescent lamp 10 according to an example of the present invention. Referring to these figures, the fluorescent lamp 10 includes a cylindrical glass tube 11. The fluorescent substance I2 is applied around the inner wall of the glass tube 11. After the fluorescent substance 12 is applied to the glass tube 11, a discharge gas including an inert gas, mercury, or the like is mixed with each other and injected into the glass tube, and both ends of the rear glass tube are tightly sealed. The glass tube 11 may have a certain cross-sectional area, such as a cylindrical shape, a flat cylindrical shape, or an overall curved multi-cylindrical shape. Referring to Fig. 1a, some of the end-covering outer electrodes 13 are formed respectively on the sealed glass tube 11, around the outer outer tube wall, on the opposite ends. According to the test results of the applicant of the present application, in order to achieve high brightness and high efficiency of the electrode, the coverage of the outer electrode portion should be ensured to be sufficiently long. Therefore, the outer electrode is formed by extending the end to cover the electrode or to bend both ends of the glass tube. Thus, the shape formed by the electrodes includes a wide variety of shapes, for example, "L" shape, "C" shape, spiral shape, wave shape, and the like. The curved outer electrode is manufactured in a variety of ways - the end portion of the straight glass tube is directly bent, or the bent portion and the glass tube which is separately manufactured and the electrode is mounted therein is connected To the ends of the straight glass tube where the fluorescent substance is applied to the surface, and so on. These outer electrodes 13 are made of a conductive material and have a shape such that they completely cover the end of the glass tube 11. The fluorescent substance cannot be coated inside the glass tube conforming to the external electrode. These external electrodes 13 can be applied to the Chinese National Standard (CNS) A4 specification (210 X 297 public) by _______17. This is the first note (please read this on the back).

Line · 1263460 A7 ______Β7___ V. Description of the invention (,) A metal strip or metal capsule is attached to both ends of the glass tube, or the end of the glass tube is bubbled into a metal solution or the like. Further, these external electrodes 13 are preferably made of a low-resistance conductive material such as aluminum, silver, copper or the like. In the present invention, in the case of a long glass tube, an end cap disposed at both ends of the glass tube is required, and a strip electrode in the middle portion of the glass tube is not required. The reason is that the longer the distance between the electrodes at the opposite ends, the more effective the brightness and efficiency of the external electrode fluorescent lamp. From the viewpoint of brightness and efficiency, the strip electrode and the end cap type electrode are disadvantageous in comparison. Further, since the electrodes disposed in the intermediate portion of the glass tube make the brightness uneven, it is disadvantageous to make the electrodes thinner. On the other hand, in order to increase the life of the glass tube and increase the generation of secondary electrons, the ferroelectric body may be coated on the inner side of the glass tube 11 corresponding to the outer electrode 13, or one surface may be coated with a medium. Individual structures are placed at the ends of the inside of the glass tube, and the ends are then sealed in sequence. Further, in addition to the ferroelectrics, magnesium oxide or calcium oxide, etc., which can be used as a protective film and which facilitates discharge of electrons, can be applied to the inner side. FIG. 2 shows that according to the present invention. The edge-emitting backlight of the second embodiment. As shown, some external electrode fluorescent lamps can be placed around the plastic optical waveguide in a variety of ways. The edge-emitting type electrode, in addition to the cold cathode fluorescent lamp, can also be used in the external electrode fluorescent lamp of the present invention because such a lamp having high brightness and high efficiency can be used by using, for example, FIG. These electrode structures of the end coated electrode and the curved electrode are realized by the driving method used in the present invention. Basically, the fluorescent- 18-slice scale of the present invention is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 public " (please read the back note before filling this page). 0 — — — — — — — « — — — — —— I— 1263460 A7 ______B7___ V. INSTRUCTIONS () The lamps are arranged in multiple places on the edge of the plastic optical waveguide, and then the lamps that are connected in parallel in parallel are separated by a single inverter. The fluorescent lamp of the present invention can be mounted on both ends of the plastic optical waveguide, or along all the edge portions of the plastic optical waveguide, and can be mounted at a plurality of ends at each end. Figure 3 shows The arrangement of some external electrode fluorescent lamps of the direct light type of the second embodiment of the present invention. The invention is characterized in that 'the use of a switching converter to drive parallel external electrode fluorescent lamps achieves high Brightness and high efficiency. A fine glass tube with an outer diameter of 2.6 mm can achieve high efficiency at an operating point of about 10,000 cd/m2. Therefore, in the case of a high-brightness surface light source, The display panel formed by direct light pattern arrangement has a brightness of 10,000 cd/m2 or higher, and the external electrode fluorescent lamp is arranged on the plane reflection plate to make the distance between the lamp and the lamp small. However, when the surface light source In the case of several 1, 〇〇〇 cd / m2, the spacing between the lamp and the lamp should be sufficient, and a special structure of the reflector for increasing its reflectivity should be used to achieve a high efficiency. Backlighting source. Basically, all the fluorescent lamps arranged on the reflector are connected in parallel and driven by a separate inverter. By placing the external electrodes® at appropriate intervals Arranged, as shown in Figure 3a, or by vertical L-shaped electrodes from the surface, as shown in Figure 3b, or by laying a l-shaped electrode on a flat surface, as shown in Figure 3c, the light cannot be The area of the electrode portion emitted therein is minimized. In Fig. 3d, in order to increase the efficiency of the illumination of the fluorescent lamp, the elongated lamps are arranged in such a manner that they are bent at the edge region of the display panel. The lamp is inserted into the external slot type multi-capsule electrode ------ -19_ This paper size applies to China National Standard (CNS) A4 specification (210 X 297 public) ' - (Please read the back note and fill out this page) -0 A7 1263460 __ B7__ V. Invention description (i) The type of structure, as shown in Figure 3e, is also used in the present invention. (Please read the note on the back and fill out this page.) Figure 3f shows the arrangement of the outer electrode for making an oversized backlight. A method of fluorescent lamps. In this case, a plurality of external electrode fluorescent lamps are arranged in the longitudinal direction of the lamp, and the reflective material is coated on the surface of the electrode, or the electrode itself is made of a transparent electrode material. This is to avoid a sudden decrease in the brightness of the electrode portion. In order to compensate for the reduction in brightness at the overlapping portions of the fluorescent lamp electrodes, the electrode portions are alternated and arranged in parallel with each other in the middle portion of the display panel. In this case, the reduction in brightness is minimized by covering the upper layer of the additional reflective material to the electrode surface located at the intermediate portion of the display panel, or by forming the electrode with the transparent electrode material. Fig. 4 shows a backlight source using a direct light type external electrode fluorescent lamp according to a second embodiment of the present invention. 'Line. Referring to FIG. 4, the reflecting plate 21 is equipped in the backlight source 20. Some of the fluorescent lamps 22 are mounted on the upper surface of the reflecting plate 21. As described above, these fluorescent lamps 22 are external electrode fluorescent lamps in which a fluorescent substance is coated on the inner circumference of the fluorescent lamp, and some external electrodes 23 made of a conductive material are respectively formed on The two ends of the outer surface of the fluorescent lamp. In order to keep their brightness uniform, a plurality of fluorescent lamps 22 are arranged at a fixed interval on the upper surface of the reflecting plate 21 in a state in which they are in close contact with each other. Further, in order to electrically connect the fluorescent lamps 22, current can flow in the outer electrodes 23 of the fluorescent lamps 22, and an electrode connecting wire 24 is connected to each of the outermost outer electrodes 23a' and extends therefrom. _20_ Home Standard (CNS) A4 Specification (210 X 297 Meals) ' 1263460 A7 ----- B7 ___ V. Invention Description (β). This causes all of the fluorescent lamps 22 to be driven in parallel when an alternating current type power source is applied thereto. A single diffusing plate 25 is mounted above the fluorescent lamps 22 opposite the reflecting plate 21. It is preferable to keep the diffusion plate 25 and the fluorescent lamp 22 appropriately spaced to prevent the image of the fluorescent lamp 22 from being formed thereon, so that the uniformity of brightness can be improved. Here, the interval between the diffusion plate 25 and the fluorescent lamp 22 corresponds to the diameter of the fluorescent lamp 22. For example, if the diameter of the fluorescent lamp 22 is 2.6 mm, the interval between the diffuser plate 25 and the fluorescent lamp 22 is also 2.6 mm. As a result, the minimum thickness will be 5.2 mm. Experiments conducted by the applicant of the present application showed that the backlight source 20 used an external electrode fluorescent lamp having an outer diameter of 2.6 mm, and obtained brightness of 10,000 cd/m2 or higher and efficiency of 50 lm/W or higher. And there is no high heat generated from the backlight. In particular, when an elongated external electrode fluorescent lamp is used, the longer the length of the lamp direction, the higher the brightness and efficiency obtained. Fig. 5 shows some of the backlights according to the second embodiment of the present invention, which relate to the shape of the outer electrode fluorescent lamp and the reflecting plate. In Fig. 5a, some of the outer electrode fluorescent lamps are arranged on a simple planar reflecting plate, and the distance between each other and the adjacent lamps corresponds to the diameter of the tube. In this case, the backlight is intended to have a higher brightness than the single lamp of Figure 4. However, in Figures 5b to 5d, the backlights are intended to have less panel brightness than a single lamp, and these lamps are arranged with a spacing of adjacent two lamps corresponding to a multiple of the diameter of the tube. In these cases, some triangular brackets are mounted on the reflector to increase its reflectivity, as shown in Figure 5b, or one - _21_ This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the notes on the back and fill out this page)

Order ·- ; Line _ A7 1263460 _B7 _ V. Description of the invention (, 丨) A concave mirror type reflector is installed, as shown in Figure 5c. Further, a reflecting plate and a diffusing plate can be mounted by using the method as shown in Fig. 5d, and then the tube is inserted into a groove formed in the plastic optical waveguide to increase the reflectivity and brightness uniformity of the backlight. According to the experiment of the applicant, the external electrode fluorescent lamp with an outer diameter of 2.6 mm was arranged on the reflecting plate with a pitch of about 15 mm, and the distance between the lamp and the diffusing plate was 25 mm, and the backlight was at the temperature. When the 値 is 1,000 cd/m2 or higher, an efficiency of 50 lm/W or higher can be achieved. Fig. 6a shows a backlight source 30 according to a second embodiment of the present invention before being combined, and Fig. 6b shows a state in which the backlight source 30 shown in Fig. 6a is combined. Referring to Figures 6a and 6b, the backlight 30 includes an upper substrate 31 and a lower substrate 32 mounted opposite the upper substrate. An upper layer of phosphor material 33 is formed on the lower surface of the upper substrate 31. A lower layer of phosphor material 34 is formed on the upper surface of the lower substrate 32. A plurality of external electrode fluorescent lamps 35 are mounted on the lower substrate 32 at predetermined intervals. These fluorescent lamps 35 are used to support the upper and lower substrates 31 and 32 when they are joined together, and are also used as a separator. According to a feature of the present invention, some outer electrodes 36 made of a conductive material are attached to both ends of the outer peripheral surface of each of the fluorescent lamps 35. In order to supply electric power to the backlight 30, the upper electrode 37 and the lower electrode 38 are mounted along the outer surfaces of the corresponding upper and lower substrates 31 and 32, respectively. Each of the upper and lower electrodes 37 and 38 is made of a conductive material and is covered with a cover over the top and bottom _____ 22 The paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the note on the back and then fill out this page) · , Line · A7 1263460 _____B7___ V. Invention Description (") Part of the outer surface of the square substrates 31 and 32. At this time, because the formation of the lower electrode 38 is enlarged The area is advantageous for obtaining a stable discharge, so it tends to arrange the lower electrode as large as possible on the bottom surface of the lower substrate 32. Some edge support frames 39 are mounted between the upper and lower substrates 31 and 32 to It is tightly sealed and maintains airtightness along the edges of the upper and lower substrates 31 and 32. Prior to sealing, a discharge gas is injected into the backlight 30, and some edge holders 39 are inserted above And between the lower substrates 31 and 32. Some of the upper and lower electrodes 37 and 38 are formed on the substrates 31 and 32, respectively, and then the current is allowed to be on the substrate 3. The two sides of 1 and 32 flow. Alternatively, after the substrates 31 and 32 are combined, the upper and lower electrodes 37 and 38 may be disposed in a unitary covering manner. The upper and lower electrodes 37 and 38 are passed through some of the substrates. 31 and 32 are connected to the electrode connection line 3 at the electrode to supply electric energy. On the other hand, the outer electrode 36 formed on the fluorescent lamp 35 is not directly connected to the upper and lower electrodes 37 and 38. Instead, they are arranged in a floating state, so that they generate a discharge phenomenon in a manner caused by the electric energy supplied to the electrodes 37 and 38. Although the external electrode % may be excluded due to some cases, The installation of this external electrode is advantageous for obtaining a stable discharge. When the backlight 30 thus constructed is supplied with electric energy via the electrode connection line 300, the external electrode fluorescent lamp 35 is individually manufactured, and then __23 —_ __ This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page) -------- ί ϋ ϋ I ϋ ϋ I n I - A7 1263460 ______Β7_ V. Description of the invention (,丨) (Please read the note on the back and fill in this page) Between the upper and lower substrates 31 and 32, so that they act as a separator and simultaneously self Fig. 6a and Fig. 6b show a basic form of a illuminator-divided panel lamp having the advantage that a voltage can be applied to the outer electrode of the plane, but there is also a need to apply The disadvantage of high voltage on it is due to the capacitance drop from the thickness of the upper and lower glass substrates. In order to improve the aforementioned drawbacks, an electrode made of a metal coated dielectric can be mounted inside the panel. That is, as shown in FIG. 6c, after the internal slot type multi-pocket electrode structure for fixing the electrodeless fluorescent lamp is mounted on the inner ends of the lower substrate, by bonding and sealing the upper and lower substrates, these The lamp can be connected to the power source via an electrode connection to the outside. The direct current cannot flow directly into the electrode because the ferroelectric is coated on the entire surface of the inner slot type multi-pocket electrode structure. As shown in Fig. 6c, the upper and lower portions (upper and lower electrodes) are individually fabricated so as to coat the ferroelectric body inside the trench, and the ferroelectric is coated on the entire surface of the trench. Then, the electrodeless fluorescent lamp is installed in the groove, and the upper and lower electrodes are joined together. Therefore, the conventional backlight cannot maintain uniform brightness because if the fluorescent lamp is used as a partition, the installation of the fluorescent lamp will darken the portion where the fluorescent lamp is mounted. However, according to the features of the present invention, uniform brightness can be obtained because the fluorescent lamp 35 will self-illuminate. Further, since the fluorescent lamp 35 can also be used as a separator, the glass thicknesses of the upper and lower substrates 31 and 32 are reduced, which is advantageous for weight reduction and enlargement of the area. _________24__ This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) A7 1263460 ______B7_____ V. Inventive Note (-/>) An inverter according to another embodiment of the present invention A backlight having an edge-light type and a direct-light type external electrode fluorescent lamp according to the foregoing embodiment is driven, and a method of operating the converter will be explained in detail. According to an example of the present invention, such a switching converter is a combination of a switching circuit and a step-up transformer. The power output is suitable for driving a square wave of electrode fluorescent lamps that are alternately connected in parallel; it can easily adjust the state of the frequency and output waveforms' and has an excessive overshoot on the output waveform. According to another example of the present invention, the split driving type is used for a large backlight source due to the planar arrangement of the external electrode fluorescent lamps, or for a large flat panel lamp whose electrodes are covered by the dielectric layer. An alternating current type of discharge is used. With the split drive type, the large area is divided into areas which are sequentially driven by waveforms having the same phase, thereby reducing the size of the driving device and enabling stable and high speed driving. Figure 7 shows the signal waveform applied to a switching converter and its gate in accordance with an example of the present invention. This device is designed to efficiently drive many external electrode fluorescent lamps that are connected in parallel in parallel. The circuit features of this device, in contrast to the inductor-capacitor resonant converter used to drive existing cold cathode fluorescent lamps, output high voltage by combining a step-up transformer and four high-speed field-effect transistors acting as switches. Square wave. Further, as shown in Fig. 7, the frequency of the output square wave, the voltage holding ratio, and the like can be easily controlled by adjusting the _ pole signal of each field effect transistor. The operating principle of the switching converter according to the present invention is as follows: ___ 25__ This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page) · _ line · A7 1263460 ___B7 ___ — V. Description of invention (ή). A DC power source is applied to the drains of the field effect transistor gates A and C mounted at the upper end of the circuit. In this state, the gate signals as shown in Fig. 7 are applied to the respective field effect transistors. Then, gates A and D are turned on and off simultaneously, and gates C and B also operate in the same manner. At this time, since the step-up transformer is connected to the output terminals of the left and right field effect transistors, when the left or right field effect transistor switches are respectively turned on, the current alternately flows into the main winding of the step-up transformer. As a result, as shown in Fig. 8, the high voltage square wave is output from the secondary coil of the step-up transformer. This output waveform is characterized by a sinusoidal wave, a short voltage rise time, and an area that maintains a fixed voltage. In addition, due to the characteristics of the turns, a transient excessive overshoot voltage is generated in a region where the voltage suddenly changes. Next, the operation method of the inverter will be explained in detail. The output voltage waveform in the form of a square wave generated by the switching converter can stably operate a plurality of external electrode fluorescent lamps connected in parallel, and obtain uniform brightness under only one switching converter. Contrary to existing inductor-capacitor resonant converters. This is because the square wave and the sine wave have different areas that maintain a fixed voltage. When the respective external electrode fluorescent lamps are turned on by simultaneously applying a square wave thereto, since the applied voltage is maintained at a fixed discharge voltage, unlike the sine wave, even if the respective external electrodes are fluorescent The lamps are sequentially turned on in one cycle of applying a voltage, and the illumination of the respective lamps becomes uniform to keep the cold light fixed uniformly. This is also because the square wave's voltage rise time is shorter than the rise time of the same sine wave with the same frequency and square wave. After these lamps are sequentially turned on and off by the initially applied voltage, many ___26_ paper sizes apply to the China National Standard (CNS) A4 specification (210 X 297 metric f) "" (Please read the back note first) Please fill out this page again)

A7 1263460 _____B7___ V. INSTRUCTIONS (,) Space charge and excited molecules are still present in the lamp' and the space charge therein is gradually formed between the space and the wall charge formed near the electrode during the initial discharge phase. The electric field recombines with the wall charge. These space charges and the movement of the excited molecules are determined by the concentration and the electric field acting on the tube as a function of time. Since the voltage rise gradient of a sine wave is always smaller than that of a square wave of the same frequency, the voltage is applied for a relatively long time before the second discharge is started. During this time, a phenomenon of wall charge elimination occurs in which the space charge is recombined by the electric field formed by the applied voltage and the wall charges formed at the initial discharge stage. Due to the above, the amount of wall charges is lowered, which results in a voltage region capable of maintaining a stable discharge, that is, a reduction in the voltage region at which the voltage boundary is maintained. As a result, the density of the discharge is also reduced, so the brightness and efficiency are lowered. However, the square wave 'outputted by the switching converter according to the present invention has a voltage rise time shorter than the sine wave, and the applied voltage is allowed to start to discharge beyond the discharge start voltage before the space charge and the wall charge are combined. Therefore, the phenomenon of wall charge elimination as described above becomes unimportant, and the holding voltage boundary allowing stable operation becomes relatively large compared to the sine wave. In addition, the effect of a steep voltage rise gradient allows for an instantaneous and rapid space charge shift so that the space charge and the effective collision between the neutral and excited molecules increase, thereby actively generating secondary electrons to make the discharge stronger. An additional effect of keeping the voltage boundary larger. As shown in Figure 9, the excessive overshoot voltage generated in the rising and falling portions of the waveform output by the switching converter promotes the onset of discharge and allows for individual adjustment of the output voltage after the discharge begins to be removed. Excessive ____27 ____ This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page) # -II----订----- ----· A7 1263460 _B7_______ V. Invention Description (,) ϋ nnn ϋ ϋ ϋ n I n I (Please read the back note first and then fill in this page) - The size of the line voltage depends on the output transformer and the external electrode Depending on the capacity of the light. The inventors found from an experiment that the enthalpy of the overshoot voltage was about 20% to 30% before the discharge was started, and decreased to less than 3% after the start of the discharge and continued. This means that the effect of excessive overshoot voltage only occurs before the discharge begins. The external electrode fluorescent lamp has the above characteristics because the external electrode fluorescent lamp has a net capacitive load before starting discharge, and has a capacitance and a resistive load after the start of discharge to generate an oscillation attenuation effect by the resistance portion of the load. As a result, this means that the excessive overshoot voltage is only effective before discharge, which promotes the onset of discharge. In general, regardless of whether the discharge tube is of an alternating current type or a direct current type, the voltage before the start of discharge is higher than the voltage at which discharge is maintained. If there is excessive overshoot in the output waveform, the applied voltage to initiate the discharge can eliminate the voltage in that portion. For example, if the discharge voltage of a discharge tube is 1300 volts and the overshoot portion of the voltage waveform used for the addition is 30%, the discharge can be initiated with only an output voltage of an average of one kilovolt. In particular, the longer the length of the external electrode fluorescent lamp, the higher the voltage at which the discharge is started. When a slender tube is used, a waveform with an excessive overshoot is advantageous. Another important effect is that there is no need for a voltage adjustment procedure that is typically done after the discharge has begun. In fact, when a waveform having no excessive overshoot is used, after starting the discharge by applying a voltage required to start the discharge on the grounds of the life of the discharge tube, the brightness adjustment, and the like, The method will be used to manually reduce the voltage. Because the switching converter has a voltage peak difference of about 20% to 30% due to the presence of excessive overshoot voltage before and after the start of discharge, the voltage is automatically adjusted after the discharge starts, and the Chinese standard is applied. (CNS) A4 specification (210 X 297 metric f) " A7 1263460 ____B7__ V. Invention description () To a level of voltage holding, it is not necessary to add a separate voltage adjustment device. In addition, due to a self-discharge effect, an increase in efficiency and brightness occurs. Self-discharge is a phenomenon that is only found in an AC discharge tube. When the voltage applied to the discharge tube is lowered to near zero potential, the wall voltage caused by the wall charge generated by the discharge is greater than the initial discharge voltage. 'A discharge phenomenon occurs between wall charges. Figure 9 shows the square wave generated by the switching converter and the self-discharge phenomenon that occurs when a square wave is applied to the external electrode fluorescent lamp. In the case of a self-discharge phenomenon, the discharge current and the number of luminescence per cycle of the voltage waveform are twice as large as when it did not occur, but the intensity is relatively small compared to the case where self-discharge does not occur. This is because some wall charges are eliminated by self-discharge. If this self-discharge phenomenon is generated, efficiency and brightness will increase. A still further embodiment of the present invention is a split drive type large area backlight source. A small backlight source constructed by arranging an external electrode fluorescent lamp on a flat surface can be driven by a single switching inverter. However, as the area becomes larger, the power consumption is also increased, and the step-up transformer used for the inverter is large in size. Therefore, it is difficult to manufacture a small switching converter. In addition, if the length of the wire to which the voltage is applied is increased, problems such as signal interference, impedance matching, and the like may occur, resulting in uneven brightness. The problem of the above case can be solved by a separate driving method in which the entire backlight source is divided into a plurality of appropriately sized regions, and the latter divided regions are outputted by the switching converter with a uniform voltage waveform having the same phase. 29______ The paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) — 111----- I — ---I----- — — — — ! (Please read the notes on the back first. Fill in this page) 1263460 a? ____B7 _ V. Invention Description (Ί) Drive, as shown in Figure 10. Here, the reason why the output waveforms of each of the switching converters must have the same phase is that if the phases are different from each other, leakage may occur in adjacent portions located between the divided regions. The method of having the output waveform of each switching converter have the same phase is to independently connect a step-up transformer in each region, and a field effect transistor for performing high-speed switching of the switching converter, and then let all The field effect transistors share a gate signal. At this time, since an electric I path for generating a gate signal is shared, compared with the case of using many switching converters, cost is saved, and the size of the step-up transformer can be reduced and can be made very close. . As described in the above, in the backlight according to the present invention, a driving method including an external electrode fluorescent lamp and a backlight, these external electrodes are mounted at both ends of the outer surface of the fluorescent lamp, and these fluorescent lights The lamps, which are arranged in sequence on one plane, get some of the phenomena described below. First, since the electrodes of the fluorescent lamp are formed on the outside, it is easy to manufacture these fluorescent lamps. By using a linear end coating or by bending both ends of the glass tube, the length of the two electrodes of the glass tube is sufficient, and high enthalpy and local efficiency have been achieved. In the form of a fluorescent lamp arranged at the edge of a plastic optical waveguide or repeatedly arranged on a plane, the fluorescent lamps are connected in parallel to a power source and can be driven by a power source, thus obtaining A thin backlight with high brightness and high efficiency and easy to manufacture. Brother One's ability to maintain uniform brightness due to the fact that the fluorescent lamp acts as a divider and simultaneously self-illuminates. Due to the use of fluorescent lamps as a separator, 30 _ (please read the notes on the back and fill out this page)

LP order--------- line. This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 metric tons). 5. Invention description (so thin upper and lower substrates can be used. Therefore, A planar light source with a large area and uniform uniformity is produced. Third, since the backlight source formed by arranging many external electrode fluorescent lamps is driven at a low frequency of several tens of kHz, electromagnetic avoidance is avoided. The problem of interference. Fourthly, due to the switching converter, according to the invention, a high-speed field effect transistor and a step-up transformer are combined to output a high-voltage square wave and generate an excessive overshoot voltage, so that a kind can be achieved. High-speed drive with uniform brightness; discharge generated voltage can be naturally reduced; and self-discharge effect can be obtained. With this effect, high brightness and high efficiency can be obtained. Fifth, according to the switching converter of the present invention, the system It is composed of a gate signal sharing a field effect transistor element and a separate connection of only the step-up transformer to divide and drive a large area of backlight In the display screen of the source, voltages with the same phase are applied to each of the divided display screens, so that leakage between adjacent divided regions can be prevented, and the discharge can be stabilized. Therefore, it can be used in a large area. Uniform brightness is obtained in the backlight source. In addition, since the length of the wire to which the voltage is applied can be reduced, the problem of signal interference and impedance matching can be avoided, which is advantageous for achieving uniform brightness results. In addition, due to the step-up transformer The size can be reduced, and the gate signal generator is shared, thus obtaining a small switching converter. Furthermore, according to the switching converter of the present invention, i) many external electrode fluorescent lamps are connected in parallel The modes are connected to each other and can be driven at a high speed by a single switching converter to obtain uniform brightness. Due to the excessive overshoot voltage 1263460 λ7 _Β7_5, the invention description (^), the voltage at the beginning of discharge can be reduced, πι The brightness and efficiency can be increased due to the presence of self-discharge. Although the present invention has been described with reference to the preferred embodiments shown in the drawings, it should be understood that the embodiments are merely illustrative, and those skilled in the art can Variants and equals. Therefore, the true scope of the invention must be defined by the scope of the patent application attached hereto. (Please read the notes on the back and fill out this page) --I----Book----------· This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) )

Claims (1)

1263460 § ^3" 3 - ^ C8 D8 VI. Patent Application 1. A backlight source comprising: a plastic optical waveguide for diffusing and emitting light emitted from an external electrode fluorescent lamp; Fluorescent lamps are arranged to surround the edge of the plastic optical waveguide. Each of the fluorescent lamps comprises a glass tube into which a discharge gas is injected and an end-covered external electrode, and a layer of phosphor is applied to the glass. The inner side of the tube is on the wall of the tube, and then the ends of the glass tube are tightly sealed, and the outer electrodes are configured to have a straight shape, an L shape, a C shape, a spiral shape, or a wave shape, and are used To cover both ends of the glass tube; and a switching inverter connected to the outer electrodes of the external electrode fluorescent lamps for applying a square wave alternating current voltage having a frequency of 100 yHz or lower to The external electrodes; and wherein the switching converter forms a bridge circuit with four field effect transistors A, B, C and D, wherein a DC power source is applied to the drains of the field effect transistors A and C The field The sources of transistors B and D are grounded, the sources of the field effect transistors A and C are connected to the drains of the field effect transistors B and D, respectively, and a step-up transformer is connected to the field effect. a connection point between the transistors A and B and a connection point of the field effect transistors C and D; and wherein the square wave parent voltage having a frequency of 100 kHz or lower is transmitted through an output portion of the step-up transformer And is output. 2. A backlight source comprising: a diffuser plate for diffusing and emitting light emitted from an external electrode fluorescent lamp; 1 the paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) ..................................IT----------- ---- (Please read the notes on the back and write this page first) 1263460 a« C8 D8 ~ ---- VI. Apply for a patent range of a reflector, which is used to reflect fluorescent lamps from these external electrodes. The emitted light; the external electrode fluorescent lamps are disposed in parallel with each other between the diffusing plate and the reflecting plate, and each of the fluorescent lamps comprises a glass tube into which a discharge gas is injected and an end covering type An electrode, and a layer of phosphor is applied to the inner wall of the inner side of the glass tube, and then both ends of the glass tube are tightly sealed, and the outer electrodes are configured to have a straight shape, an L shape , C-shaped, spiral, or wavy, and used to cover both ends of the glass tube; and a switching inverter connected to the external electrode fluorescent lamps External electrode for applying a square wave alternating voltage having a frequency of 100 kHz or lower to the external electrodes; and (wherein the switching converter is composed of four field effect transistors A, B, C and D a bridge circuit in which a DC power source is applied to the drains of the field effect transistors A and C, the sources of the field effect transistors B and D are grounded, and the sources of the field effect transistors A and C are respectively Connected to the drains of the field effect transistors B and D, and a step-up transformer is connected between the junction of the field effect transistors A and B and the junction of the field effect transistors C and D; The square wave AC voltage having a frequency of 100 kHz or lower is output through an output portion of the step-up transformer. 3. The backlight according to claim 2, wherein the reflector further includes a plurality of a triangular bracket inserted between the external electrode fluorescent lamps. 4. The backlight according to item 2 of the patent application scope, wherein the reflection 2 __ the paper scale is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) .............. ..-费·......,......· # ;!: ! · (Please read the notes on the back and write this page first) 1263460 运C8 D8 VI. Patent application board is wrapped in wavy form The external electrode fluorescent lamp. The backlight according to claim 2, wherein the diffusing plate comprises a diffusion groove in a portion where the external electrode fluorescent lamp is disposed; the reflecting plate is triangular a sawtooth form; and the backlight further includes a plastic optical waveguide disposed between the diffusion plate and the reflection plate, and a top end portion of the waveguide is provided with a diffusion in which the external electrode fluorescent lamps are seated The groove, and the bottom end portion thereof is triangular jagged to be in close contact with the reflecting plate. .6—a backlight source comprising: a diffuser plate for diffusing and emitting light emitted from an external electrode fluorescent lamp; and a reflector for reflecting light from the outer electrode Light emitted by the light lamp; the fluorescent lamp comprises a glass tube disposed between the diffusion plate and the reflection plate in parallel with each other and an external slot type multi-capsule electrode structure, and the glass tube system is injected with a discharge a gas, and a layer of phosphor is applied to the inner wall of the glass tube, and then the ends of the glass tubes are tightly sealed, and the electrode structures have a plurality of external electrodes connected in parallel, a plurality of glass tubes coupled to the outer electrodes; and a switching inverter coupled to the outer slot type multi-pocket electrode structures for application with a frequency of 1 kHz or lower a square wave alternating voltage to the outer slot type multi-pocket electrode structures; and wherein the switching converter forms a bridge circuit with four field effect transistors A, B, C and D, wherein a DC power source is applied To that Effect Electric 3 Paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) ---------------------a....... .丨丨定---------------- (Please read the note on the back and write this page first) 1263460 - C8 D8 VI. Patent Application Range* Crystals A and C The source of the field effect transistors B and d is grounded. The sources of the field effect transistors A and C are respectively connected to the drains of the field effect S crystals B and D, and a step-up transformer. Connected between the junction of the field effect® crystals A and B and the junction of the field effect transistors C and D; and wherein the square wave alternating voltage having a frequency of 1 kHz or lower is transmitted through the An output portion of the step-up transformer is output. 7. A backlight source comprising: a diffuser plate for diffusing and emitting light emitted from a plurality of external electrode fluorescent lamps; and a reflective plate for reflecting from the outer electrodes The light emitted by the fluorescent lamp; the plurality of external electrode fluorescent lamps having external electrode portions arranged in a staggered manner laterally overlapping each other in the middle of a display panel between each of the diffusion plates and the reflective plate The fluorescent lamps each include a glass tube into which a discharge gas is injected and an end-covered external electrode, and a layer of phosphor is applied to the inner wall of the inner side of the glass tube, and then the ends of the glass tube are closely Sealed, and the outer electrodes are used to cover both ends of the glass tube; and a switching inverter is connected to the outer electrodes of the outer electrode fluorescent lamps for application with a frequency of 100 a square wave alternating voltage of kHz or lower to the outer electrodes; and wherein the switching converter forms a bridge circuit with four field effect transistors A, B, C and D, wherein a direct current power source is applied thereto The anodes of the effect transistors A and C, the sources of the field effect transistors B and d are connected to the four-dimensional Chinese National Standard (CNS) A4lwiT (210 X 297 public) one ..... .....1!·〒! ..........book---------------,^9. (Please read the notes on the back and write this page first) 1263460 Lotus C8 D8 VI. In the patent application scope, the sources of the field effect transistors A and C are respectively connected to the drains of the field effect transistors B and D, and a step-up transformer is connected to the field effect transistors A and B. The connection point is between the connection points of the field effect transistors C and D; and wherein the square wave AC voltage having a frequency of 100 kHz or lower is output through an output portion of the step-up transformer. 8. The backlight according to claim 7, wherein the external electrode fluorescent lamps are alternately disposed to overlap each other laterally in the middle of the display panel, and the electrode portion is a conductive transparent electrode material. Made of. 9. A backlight source comprising: an upper substrate having an upper layer of phosphor material applied to a bottom surface of the upper substrate; a lower substrate having a lower layer of phosphor material applied thereto a lower surface of the lower substrate, the lower substrate is mounted opposite the upper substrate; and some edge support frames are inserted between the upper and lower substrates to tightly seal the upper and lower substrates; The external electrode fluorescent lamp is mounted on the lower substrate at a predetermined interval, and each of the fluorescent lamps comprises a glass tube into which a discharge gas is injected and an end-covered external electrode, and a layer of fluorescent substance Is applied to the inner wall of the inner side of the glass tube, and then the ends of the glass tube are tightly sealed, and the outer electrodes are used to cover both ends of the glass tube; a discharge gas system It is injected into the inner space when sealing the upper and lower substrates; 5 ΐ paper scale is applicable to China National Standard (CNS) A4 specification (210 X 297) PCT) : ...................衣---- (Please read the notes on the back and fill out this page) 11T-. 1263460 C8 D8 VI. Apply for a patent a plurality of electrodes formed on respective outer side surfaces of the combined upper and lower substrates and connected to an electrode connection line for applying an alternating current power source; a switching converter Connected to the electrodes' to apply a square wave alternating voltage having a frequency of 100 kHz or lower to the electrodes; and wherein the switching converter is connected to four field effect transistors A, B, C and D constitutes a bridge circuit in which a DC power source is applied to the drains of the field effect transistors A and C, the sources of the field effect transistors B and D are grounded, the sources of the field effect transistors A and C Connected to the drains of the field effect transistors B and D, respectively, and a step-up transformer is connected between the junction of the field effect transistors A and B and the junction of the field effect transistors C and D; And wherein the square wave AC voltage having a frequency of 100 kHz or lower is transmitted through the step-up voltage An output section is output. 10. The backlight according to claim 9, wherein the external electrode fluorescent lamps are not connected to the electrodes, but are disposed between the upper and lower substrates in a floating state. 11. A backlight source, comprising: an upper substrate having an upper layer of phosphor material applied to a bottom surface of the upper substrate; a lower substrate mounted on the opposite side of the upper substrate and having A layer of underlying phosphor is applied to the top surface of the lower substrate; some edge supports are inserted into the upper and lower substrates at 6 "^^ scales applicable to China National Standard (CNS) A4 specifications (210x29^ ^7 ' ......................!. (Please read the notes on the back and write this page again) 11T: ABCD 1263460 VI. Between the scope of application for the purpose of tightly sealing the upper and lower substrates; some internal slot-type polycapsule electrode structures are coupled by some of the surface coated ferroelectrics and are predetermined The upper and lower electrodes of the trenches are formed by the spacing and then respectively mounted on the two ends of the lower substrate; some glass tubes are mounted on the trenches of the inner slot type multi-capsule electrode structure Inside, each glass tube has a discharge gas injected therein and the inner peripheral wall is coated with a layer of phosphor material, the ends of which are tightly sealed; the heavy discharge gas is tied The upper and lower substrates are sealed into an internal space; and a switching inverter is connected to the internal slot type multi-pocket electrode structures for applying a frequency of 100 kHz or lower. Wave alternating voltage to the internal slot type multi-pocket electrode structures; and wherein the switching converter is constructed of four field effect transistors A, B, C, and D a bridge circuit in which a DC power source is applied to the drains of the field effect transistors A and C, the sources of the field effect transistors b and d are grounded, and the sources of the field effect transistors A and C are respectively Connected to the drains of the field effect transistors B and D, and a step-up transformer is connected between the junction of the field effect transistors A and B and the junction of the field effect transistors c and D; A square wave parent current voltage having a frequency of 1 〇〇 kHz or lower is output through an output portion of the step-up transformer. 12. A backlight according to the scope of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 wherein the square wave output from the switch converter is 7 China National Standard (CNS) A4 specification (210 X 297 mm) (Please read the notes on the back and fill out this page) 1263460 ah B8 C8 D8 __ VI. Scope of Application (Please read the note on the back and write this page first) The AC voltage system includes an excessive overshoot to cause discharge of the external electrode fluorescent lamps. 13. A method for driving a backlight having a plurality of external electrode fluorescent lamps, the method comprising the steps of: dividing the plurality of external electrode fluorescent lamps into a plurality of predetermined regions; The electrode connection lines are respectively connected to the external electrodes of the electrode fluorescent lamps located outside the individually divided regions; the switching converters are respectively connected to the 11-pole connecting lines connected to the individual divided regions; applying the same gate a pole signal to each of the switching converters; and in response to the gate signal, the switching inverters provide a square wave AC voltage having an in-phase frequency of 100 kHz or lower to the external electrode fluorescent lamps; And wherein the switching converter forms a bridge circuit with four field effect transistors A, B, C and D, wherein a DC power source is applied to the drains of the field effect transistors A and C, the field effect electric The sources of crystals B and D are grounded, the sources of the field effect transistors A and C are connected to the drains of the field effect transistors B and D, respectively, and a step-up transformer is connected to the field effect transistor A and B The connection point is between the connection points of the field effect transistors c and D; and wherein the square wave AC voltage having a frequency of 1 kHz or lower is output through an output portion of the step-up transformer. 8 This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm)