Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/92—Lamps with more than one main discharge path
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/30—Vessels; Containers
  • H01J61/305—Flat vessels or containers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/56—One or more circuit elements structurally associated with the lamp

Definitions

• the present invention relates to a discharging lamp, and more particularly to a discharging lamp, in which a plurality of discharging electrode pairs are arranged within a discharging bulb to allow the discharging electrode pairs to operate as a flat light source by switching discharges at high speed.
• a discharging lamp is a lighting fixture that utilizes a common phenomenon of emitting energy equivalent to an energy-level difference in the form of light during a transition of atoms from an excited state to a ground state.
• the discharging lamp is classified into a high-pressure discharging lamp and a low-pressure discharging lamp in accordance with the high and low state of a gas pressure within the lamp during the discharging operation.
• a fluorescent lamp is a typical representative of low-pressure discharging lamp while a metal halide lamp, a mercury lamp and a xenon lamp chiefly employed at outdoors are examples of high-pressure charging lamp.
• the discharging lamp is applied as a backlight of an advertising plate or an image apparatus in addition to its use as a general illuminating source.
• a planar light source especially a flat light source, is more suitable than a point light source or a line light source.
• the flat light source achieves more comfortable level of lightening in indoor atmospheres.
• the advertising plate is generally fiat-shaped. Hence, if the line light source or point light source is utilized as the backlight, the advertising plate tend to get stained because of inconsistent luminance. For this reason, it is more effective to employ a flat light source for consistently radiating the light across the advertising plate.
• planar display panels such as LCD panel, having a passive light emitting device, which is intrinsically unable to radiate light by itself in view of its characteristics, requires the flat light source as the backlight.
• a light guiding plate or a diffusion plate is further employed.
• a LCD panel apparatus further has light guiding plates and diffusion plates of complicated structures for providing a consistent surface luminance to the panel while employing a slim cylindrical fluorescent light as backlight.
• the light guiding plate and the diffusion plate increase the manufacturing cost and are difficult to construct.
• those employed cause a light transmission loss to adversely affect the power efficiency during the high luminance of LCD panel.
• the lamps employ circular, elliptical or cylindrical shapes due to the mechanical stableness of these shapes. That is, as the interior of the discharging lamp is under a high vacuum state for performing the effective discharge, the above structures are considered optimum in preventing the breakage of the lamp by external air pressure.
• FIGS. 1a and 1b A trial for constructing the discharging lamp by the flat type has been attempted.
• a technique disclosed in U.S. Patent. 4,945,281 entitled: “Flat Light Source” is a one example.
• a representing structure of the discharging bulb disclosed in the above patent is shown by FIGS. 1a and 1b.
• a discharging bulb 4 as shown in FIG. 1a is formed by up and down flat- type transparent glasses, and spacers 3 for counteracting against external air pressure are installed between up and down flat glass plates.
• a plurality of pairs of discharging electrodes 1 are arranged at both sides of plurality of discharging channels 2 partitioned by spacers 3.
• the plurality of discharging electrodes pairs are simultaneously supplied with an electric power.
• the power is simultaneously supplied to the plurality of discharging electrode pairs, all discharging electrode pairs are not discharged but the discharge occurs in discharging channel with the weakest insulating tolerance between the positive discharging electrode and negative discharging electrode while the remaining discharging channels are not involved in the discharging process.
• discharging bulb 8 As the result, although the discharging bulb of the above patent has the flat- type structure, it has a problem in that, because the discharge occurs in a single discharging channel, only the line light source effect instead of the flat light source effect is observed.
• the above U.S. Patent also suggests another example of the discharging bulb, which is discharging bulb 8 as shown in FIG. 1b.
• Discharging bulb 8 is constructed in a manner that spacers 6 are arranged to form the discharging channel 7 in zigzags between the flat-type upper and lower glasses, and a pair of discharging electrodes 5a and 5b are arranged in the left upper corner and right lower corner. According to this structure, the large discharging bulb increases the length of the discharging channel. As a result, a higher discharge maintenance voltage is needed. Thus, there are many difficulties in embodying it as an actual product.
• the above patent does not suggest a satisfactory solution with respect to the electrical discharging mechanism capable of consistently inciting the discharge throughout the flat light source.
• the important object of the flat light source is to achieve an uniform luminance throughout the plane having a prescribed area. Therefore, the stable structure of the discharging bulb is one requirement, however is alone is not a sufficient condition to obtain uniform luminance.
• a flat light source apparatus capable of providing an uniform surface luminance by arranging a plurality of discharging electrode pairs within a structurally stable discharging bulb having a wide surface area to uniformly discharge the discharging electrode pairs.
• a flat light source apparatus having multi-electrodes capable of shifting a discharging path.
• the flat light source apparatus has a discharging lamp and an electrode select section.
• the discharging lamp includes a tightly closed discharging bulb sealed with a discharging substance therein for externally transmitting light generated by the discharge, and a plurality of discharging electrode groups respectively installed to areas spaced apart from one another within the discharging bulb.
• Respective discharging electrode groups include a plurality of discharging electrodes.
• the electrode select section controls by switching a path of supplying the electric discharging power at a predetermined frequency with respect to the discharging electrode pairs intended to incite the discharge in a predetermined order, so that the plurality of discharging electrodes have a substantially equal discharging opportunity.
• the structure of the discharging bulb may have an optional shape. In order to obtain a flat light source, a flat-type discharging bulb having at least one flat or almost flat plane is preferable.
• the electrode select section controls the supply of the electric discharging power for making the discharging path move in accordance with a determined switching sequence so as to form a consistent luminance over the surface of the discharging bulb.
• respective discharging frequencies of discharging electrode pairs are to be higher than a critical fusion frequency.
• the electrode select section includes a switching unit for controlling to supply the electric discharging power only to the discharging electrode pair designated by the switching control signal by switching in response to the switching control signal, and a switching control unit for generating the switching control signal to supply it to the switching unit.
• the switching control unit can be formed by a software-based system or hardware-based system solely.
• a microcomputer included with a program capable of forming the switching control signal is formed as the switching control unit.
• the switching control unit includes a counting portion for receiving count clock signals and an output logic portion for receiving an output value of the counting portion to provide the switching control signal.
• the discharging electrode group includes first and second discharging electrode groups serving as a negative pole and a positive pole.
• the switching unit includes a first switching device group having a plurality of switching devices connected to respective discharging electrodes included to the first discharging electrode group one by one while being connected in parallel with a first polarity of a power source section for supplying the electric discharging power.
• a second switching device group included to the switching unit has a plurality of switching devices connected to respective discharging electrodes included to the second discharging electrode group one by one while being connected in parallel with a second polarity of the electric discharging power via a stabilizing circuit.
• the discharging electrode group is formed by first and second discharging electrode groups to serve as a negative pole and a positive pole.
• the switching unit has a first switching device group connected to respective discharging electrodes included to the first discharging electrode group one by one, and a second switching device group connected to respective discharging electrodes included to the second discharging electrode group one by one.
• the switching devices included to the first switching device group is further divided into a plurality of small groups, and the switching devices included to respective small groups are connected in parallel with the stabilizing circuits separately provided to respective small groups.
• Respective stabilizing circuits are connected in parallel with the first polarity of the power source section for supplying the electric discharging power, and the switching devices included to the second switching device group are connected in parallel with the second polarity of the power source section.
• the discharging electrode group has first, second and third discharging electrode groups arranged to both ends and the center of the discharging bulb.
• the switching unit includes a first switching device group having a plurality of first switching devices connected to respective discharging electrodes included to the first discharging electrode group one by one while being connected in parallel with the first polarity of the first power source section for supplying the electric discharging power via a first stabilizing circuit.
• a second switching device group having a plurality of second switching devices connected to respective discharging electrodes included to the second discharging electrode group one by one while being connected in parallel with the first polarity of the second power source section for supplying the electric discharging power via a second stabilizing circuit
• a third switching device group having a plurality of third switching devices connected to respective discharging electrodes included to third discharging electrode group one by one while being commonly connected in parallel with the second polarity of the first and second power source section.
• the switching control unit is connected to respective switching devices of the first, second and third switching device groups for supplying the same switching control signal to the switching device pairs connected to the discharging electrode pairs facing with one another. Further to these, the discharging electrode pairs are designated by the switching control signal such that all or part of the discharging electrode pairs constituting the discharging electrode groups are designated to incite the whole discharge or local discharge as required.
• the electrode select section controls the supply of the electric discharging power for performing a sequential discharge that moves the position of the discharging electrode pair for inciting the discharge to the immediately adjacent discharging electrode pair for each discharge, or for performing an interlaced discharge that moves the position of the discharging electrode pair for inciting the discharge to the alternately skipped adjacent discharging electrode pair for each discharge.
• the discharging bulb has a flat-type or substantially flat-type light emitting surface.
• the discharging bulb includes a flat light transmitting plate for externally transmitting the light produced by the discharge, a flat reflecting plate facing with the flat light transmitting plate spaced apart from each other by a prescribed interval for reflecting the light toward the flat light transmitting plate, and at least one supporting portion arranged to support between the flat light transmitting plate and flat reflecting plate.
• the discharging bulb includes first and second flat light transmitting plates arranged to face with each other spaced apart from each other by a prescribed interval for externally transmitting the light produced by the discharge, and at least one supporting portion arranged to support between the first and second flat light transmitting plates.
• the discharging electrode group includes a first discharging electrode group and a second discharging electrode group respectively installed to opposing first and second corners of the discharging bulb, and a plurality of discharging electrodes of respective discharging electrode groups are arranged at equal distances.
• the discharging electrode group includes first, second and third discharging electrode groups respectively arranged to the opposing first and second corners and between the two corners of the discharging bulb, and a plurality of discharging electrodes are arranged at equal distances.
• the discharging bulb is formed as one-sided light emitting fluorescent light or both-sided light emitting fluorescent light by coating a fluorescent material over the inner surface of one side or facing two sides.
• the discharging bulb includes a light transmitting plane coated with the fluorescent material over the inner surface thereof, and a reflecting plane for reflecting the light produced by the discharge toward the light transmitting plane by coating a reflecting layer over the inner surface of the plane facing with the light transmitting plane. This is for enhancing the light emitting efficiency of the one-sided light emitting type.
• FIGS. 1a and 1b show constructions of a conventional flat-type discharging lamp
• FIG. 2 is a concept view showing a flat-type discharging lamp according to a first embodiment of the present invention
• FIG. 3 is a concept view showing the flat-type discharging lamp according to a second embodiment of the present invention.
• FIG. 4 is a concept view showing the flat-type discharging lamp according to a third embodiment of the present invention
• FIGS. 5a and 5b are sectional views showing the discharging bulb of FIG.
• FIGS. 6a and 6b are sectional views showing the discharging bulb of FIG.
• FIGS. 7a and 7b are sectional views showing the discharging bulb of FIG. 4 respectively taken along lines E-E' and F-F';
• FIGS. 8a to 8i show a first example of switching pulses supplied from the switching controller via nine output ports
• FIGS. 9a to 9c show a second example of the switching pulses supplied via three output ports
• FIGS. 10a to 10d show a third example of the switching pulses supplied via four output ports
• FIG. 11 shows a construction of a first embodiment of the switching controller having nine output ports for generating the switching pulses shown in FIGS. 8a to 8i;
• FIG. 12 shows a construction of a second embodiment of the switching controller having three output ports for generating the switching pulses shown in FIGS. 9a to 9c; and
• FIG. 13 is a concept view showing a discharging lamp according to a fourth embodiment of the present invention.
• FIG. 2 is a concept view of a flat-type discharging lamp according to a first embodiment of the present invention.
• the discharging lamp includes a discharging bulb 10 shaped as a thin hexahedron long in width and length, of which upper plate and lower plate opposing to each other are supported by a plurality of supporting members 14.
• FIGS. 5a and 5b are for illustrating one embodiment of the structure of discharging bulb 10, taken along lines A-A' and B-B' of discharging bulb 10 of FIG. 2.
• Upper plate 74 and lower plate 76 of discharging bulb 10 are supported in parallel by means of a plurality of supporting bars 72.
• the material or construction of discharging bulb 10 may differ in accordance with the both-sided light emitting type or single-sided light emitting type.
• both upper plate 74 and lower plate 76 are formed of a transparent substance having a good light transmitting efficiency.
• the substance utilized in manufacturing upper plate 74 and lower plate 76 may be formed of a glass composite widely-employed as a discharging bulb material such as soda lime glass, lead glass, Pyrex borosilicate glass and quartz glass, a light-transmitting polycrystalline alumina (Al 2 0 3 ) or alumino boro glass (AI 2 0 3 -B 2 0 3 -BaO-CaO system) and so on.
• the other plate may be formed by different substance, but it is preferable that the thermal expansion coefficient is identical to that of the transparent substance.
• Both upper plate 74 and lower plate 76 are preferably formed of the substance having an excellent mechanical strength so as to endure an air pressure.
• fluorescent materials 78 and 80 are coated over the inner walls of upper plate 74 and lower plate 76.
• the fluorescent material is coated over the inner walls of upper and lower plates 74 and 76 as the both-sided light emitting type.
• Discharging bulb 10 is provided with an exhaust and a vacuum environment therein, and a rare gas such as Ne, He, Kr, Ar and Xe and a metal vapor such as Hg, Na and Cd are selectively sealed therein in accordance with the kind of the discharging lamp.
• a rare gas such as Ne, He, Kr, Ar and Xe
• a metal vapor such as Hg, Na and Cd
• the fluorescent lamp is generally sealed with a mercury vapor of approximately 5x10 "3 [torr] as the metal vapor and an Ar gas of approximately 2 ⁇ 3[torr] as the rare gas.
• a mixture such as Ar+Kr, Kr+Ne, Ar+Ne and Ne+Be may be sealed thereto, and the quantity of the rare gas sealed therein may be differently determined in terms of the discharging states such as the size of the discharging bulb.
• the number of the supporting bars can be decided diversely in respect to several variables such as the internal vacuum of discharging bulb 10, the substance strength of discharging bulb 10 and supporting bars and the contact area between discharging bulb 10 and supporting bars 72.
• the supporting bars are not restricted by the constituting substance once it has an intensity strong enough to endure the air pressure imposed upon the upper and lower planes of discharging bulb 10, which may be constituted by, e.g., steel, hard plastic and high tempered glass.
• Discharging electrode 86 is formed by applying an electron emitting material (e.g., an oxide mainly formed of Barium, Strontium and Calcium) on double or triple filament consisting of tungsten. Discharging electrode 86 is supported by a lead line penetrating through stem 87 and simultaneously connected to an external base pin 88 out of discharging bulb 10. The exterior of stem 87 is finished by means of an adhering sealer 82, and a base cap 84 is attached thereon.
• an electron emitting material e.g., an oxide mainly formed of Barium, Strontium and Calcium
• the first discharging electrode group has a plurality of coil-like discharging electrodes P1 , P2, ... and P9 arranged to be spaced apart from one another at equal distances
• the second discharging electrode group also has the same number of coil-like discharging electrodes P1 ⁇ P2', ... and P9' arranged to be spaced apart from one another at equal distances.
• Respective discharging electrodes are connected to two base pins (88 of
• FIG. 5a out of discharging bulb 10 via lead lines.
• First output terminals of respective discharging electrodes P1 , P2, ... and P9 of the first discharging electrode group are commonly connected to the base pin, and first output terminals of respective discharging electrodes P1', P2', ... and P9' of second discharging electrode group are commonly connected. Both common connection points are connected to both ends of a starting device 18.
• second output terminals of respective discharging electrodes P1 , P2, ... and P9 of the first discharging electrode group are connected to upper switching devices S1 , S2, ... and S9 one by one
• second output terminals of respective discharging electrodes P1', P2', ... and P9' included to the second discharging electrode group are connected to lower switching devices R1 , R2, ... and R9 one by one
• Upper switching devices S1 , S2, ... and S9 and lower switching devices R1 , R2, ... and R9 are commonly connected to both sides of power source section 20, respectively.
• a reference alphabet Z denotes an equivalent impedance of a stabilizing circuit 22.
• stabilizing circuit 22 is arranged between power source section 20 and upper switching device 12a or lower switching device 12b.
• Upper and lower switching devices 12a and 12b can cover a rated current and a rated voltage of the discharging lamp, which preferably has a fast response speed.
• a semiconductor switching device including a photo electric switch formed by a light emitting diode and a photo transistor, an electric field effect transistor MOSFET or bipolar transistor may be given as a representative one.
• a switching controller 16 is provided to control the switching operation of upper and lower switching devices 12a and 12b.
• Switching controller 16 has output ports corresponding to the number of the discharging electrode pairs installed within discharging bulb 10. There are nine output ports of switching controller 16 since discharging bulb 10 of FIG. 2 includes nine discharging electrode pairs.
• switching controller 16 provides, e.g., 16 switching pulses for one period 0 ⁇ ti 6 via nine output ports.
• FIG. 13 shows a construction of switching controller 16 for generating the switching pulses as shown in FIGS. 8a to 8i.
• switching controller 16 includes an up-counter 200 for receiving a clock signal CLK to count from zero to 15, and an output logic 210 for receiving count signals from output ports PO, P1 , P2 and P3 of up-counter
• Output logic 210 includes nine logic circuits 220, 230, 240, 250, 260, 270, 280, 290 and 300.
• the input ports of respective logic circuits are commonly connected to four output ports P0, P1 , P2 and P3 of up-counter 200.
• switching controller 16 selects one discharging electrode respectively from first discharging electrode group P1 , P2, ... and P9 and second discharging electrode group P1', P2' ... and P9' for designating one pair of discharging electrodes which are to currently incite the discharge. Selected discharging electrodes are applied with an electric discharging power from power source section 20. The selection of the discharging electrode pair is performed by an output signal of switching controller 16.
• mapping relation between output values of output logic 210 with respect to the output values of up-counter 200 for one period to ⁇ t 16 can be listed as [Table 1] below.
• the discharging electrode pair intended to be currently supplied with the electric discharging power is placed to be as near as possible to the discharging electrode pair which incited the previous discharge.
• a first connecting system of [Table 2] is of a sequential switching discharge
• a second connecting system is of an interlaced switching discharging.
• the discharging path for one period to ⁇ ti 6 is to be moved from the left to the right of discharging bulb 10 and then from the right to the left in the order that (P1 , P1') ⁇ (P2, P2') ⁇ (P3, P3') ⁇ (P4, P4') ⁇ (P5, P5') ⁇ (P6, P6') ⁇ (P7, P7') ⁇ (P8, P8') ⁇ (P9, P9')- ⁇ (P8, P8') ⁇ (P7, P7') ⁇ (P6, P6') ⁇ (P5, P5') ⁇ (P4, P4') ⁇ (P3, P3') ⁇ (P2, P2').
• the discharging electrode pair can maximally utilize the ionized gas ambient formed by the prior discharge. Accordingly, it has an advantage of easily inciting the discharge even without applying a high starting voltage to the discharging electrodes.
• the sequential discharging system is more favorable to the interlaced discharging system. However, if the distance between adjacent discharging electrodes is not too far, the interlaced discharging system may utilize the above effect.
• FIG. 3 is a concept view showing the flat-type discharging lamp according to a second embodiment of the present invention. This embodiment is same as the foregoing embodiment in that individual switching device is connected to each discharging electrode one by one. Whereas it is characterized in having a connecting system that the discharging electrode pairs are classified into several groups, and a separate stabilizing circuit Z is allotted to respective groups.
• FIGS. 6a and 6b are sectional views of another embodiment of discharging bulb 10 taken along lines C-C and D-D'.
• a supporting member 106 of an upper plate 98 and a lower plate 100 is shaped as a ball without the bar shape.
• Ball-shaped supporting member 106 reduces the contact area with upper and lower plates 98 and 100 as compared with those of the bar shape to better the luminance consistency across the surface of discharging bulb 10.
• This embodiment is provided for showing the possibility of modifying the shape of supporting member 106 in various forms, which is not necessarily of the ball shape but another form such as the bar shape may be applied.
• a discharging electrode 90 is a pin type in this embodiment, which is presented to put no restriction in the shape of the discharging electrode according to the present invention.
• the pin-type discharging electrode has one base pin 92 which is connected by means of a lead line 97 to each discharging electrode.
• a supporting wall 108 is arranged along the four-sided peripheries of upper and lower plates 98 and 100. Supporting wall 108 and end portions of upper and lower plates 98 and 100 are sealed with an adhering sealer 96, and then is covered with a base cap 94. Also, a pin-like discharging electrode 90 is arranged in the vicinity of supporting wall 108 within discharging bulb 10 (the discharging electrode may be formed as the coil as in the foregoing example). Discharging electrode 90 is connected to base pin 92 out of base cap 94 via lead line 97 that penetrates through supporting wall 108 and adhering sealer 96.
• a first discharging electrode group 52a including a plurality of pin-like discharging electrodes K1 , K2, ... and K9 arranged at equal distances is arranged to the upper end of flat type discharging bulb 10.
• a second discharging electrode group 52b including a plurality of pin-like discharging electrodes K1 ⁇ K2", ... and K9' arranged at equal distances is arranged to the lower end of discharging bulb 10 while opposing first discharging electrode group 52a.
• First discharging electrodes K1 , K2, ... and K9 are connected with nine first switching devices E1 , E2, ... and E9 one by one.
• second discharging electrodes K1 ⁇ K2', ... and K9' are connected to nine second switching devices G1 , G2, ... and G9 one by one.
• first stabilizing circuit 56a is added between power source section 58 and first switching device group E1 , E2 and E3
• second stabilizing circuit 56a' is added between power source section 58 and second switching device group E4, E5 and E6 while adding third stabilizing circuit 56a" between power source section 58 and third switching device group E7, E8 and E9.
• switching controller 54 has at least three output ports.
• FIG. 12 shows in detail one embodiment of constructing switching controller 54.
• switching controller 54 has an up-counter for receiving a clock signal CLK to count from zero to five, and an output logic 310 for receiving the count signals from three output ports PO, P1 and P2 of up-counter 300 to provide the switching signals as shown in FIGS. 9a to 9c for one period to ⁇ t ⁇ .
• Output logic 310 includes three logic circuits 320, 330 and 340. The input ports to respective logic circuits are commonly connected to three output ports P0, P1 and P2 of up-counter 300.
• First logic circuit 320 is connected to first switching devices E1 , E4, E7, G1 , G4 and G7 of respective switching device groups, and second output port 330 is connected to second switching devices E2, E5, E8, G2, G5 and G8 of respective switching device groups.
• Third output port 340 is connected to third switching devices E3, E6, E9, G3, G6 and G9 of respective switching device groups.
• FIG. 4 is a concept view showing the flat-type discharging lamp according to a third embodiment of the present invention.
• This embodiment is characterized in that nine pin-like discharging electrodes H1 ⁇ H2', ... and H9' are further arranged to the center portion of discharging bulb 10 in addition to installing respectively nine pin-like discharging electrodes H1 , H2, ... and H9 and H1", H2", ... and H9" to the upper end portion and lower end portion within discharging bulb 10.
• Discharging bulb 10 is the flat type having a structure illustrated in FIGS. 7a and 7b which are sectional views when taken along lines E-E' and F-F 1 of discharging bulb 10, respectively.
• the structure is almost similar to that of discharging bulb 10 as shown in FIGS. 6a and 6b, but it is different in that a discharging electrode 93 is additionally arranged in the center portion of discharging bulb 10 and discharging electrode 95 is connected to an external base pin 95 out of discharging bulb 10 via a lead line 99.
• respective discharging electrodes H1 , H2, ... and H9 of first discharging electrode group are connected to first switching devices U1 , U2, ... and U9 one by one, and first switching devices U1, U2, ...
• Respective discharging electrodes H1', H2', ... and H9' of second discharging electrode group are connected to second switching devices C1 , C2, ... and C9 one by one, and first switching devices C1 , C2, ... and C9 are commonly connected in parallel with first power source 34a and a second power source 34b.
• Respective discharging electrodes H1", H2", ... and H9" are connected to third switching devices D1, D2, ... and D9 one by one, and third switching devices D1 , D2, ... and D9 are connected in parallel with second power source 34b via second stabilizing circuit 36b.
• Switching controller 40 employs the construction of that shown in FIG. 12, and the connection among nine output ports 220 to 300 and first, second and third switching devices 32a, 32b and 32c is as shown in [Table 3].
• the discharging electrode installed to the center portion of discharging bulb 10 is preferable when discharging bulb 10 is large in size. That is, when discharging bulb 10 is significantly large, the distance between the discharging electrodes installed to both ends of discharging bulb 10 is too far to easily incite the discharge. For this reason, the discharging electrode is further installed to the center of the discharging bulb to make the interval between the discharging electrodes short.
• the discharging path for one period to ⁇ t ⁇ 6 is sequentially moved from discharging electrode pair H1 , H1' and H1" to discharging electrode pair H9, H9' and H9" and then the discharging path sequentially return in the reverse direction to discharge electrode pair H2, H2' and H2".
• FIG. 7 shows another embodiment of the discharging bulb structure.
• An upper plate 150 is a transparent plate having a slight curvature, and the inner surface thereof is coated with a fluorescent material 154.
• a lower plate 152 is formed with a reflecting layer 156 over the inner surface thereof, and is coupled with both ends of upper plate 150 via grooves formed along both ends thereof. The coupling portion is choked with an adhesive closing stuff 152.
• a plurality of supporting members 158 are installed between upper plate 150 and lower plate 152 to offer a countering force against external air pressure. Similar to the foregoing embodiment, a plurality of discharging electrodes 160 are arranged at both ends of the discharging bulb by a prescribed interval. This embodiment is provided to indicate the possibility of applying the present invention having any optional form without being limited to the flat type discharging bulb so far as a slight space is provided within the discharging bulb.
• respective switching controllers 16, 54 and 40 of the above- described embodiments may be formed by means of a microcomputer (not shown). Any microcomputer is acceptable only when involving output ports corresponding to the discharging electrode pairs, and a program for permitting the switching signals as shown in FIGS. 8a to 8i or 9a to 9c to be supplied via respective output ports is included in the microcomputer.
• the program for outputting the switching signals may be easily embodied by those skilled in the art once the timing charts of the switching signals having the desired formats are decided, of which description will thus be omitted. If the flat-type discharging bulb according to the present invention is applied to, e.g., the backlight of the LCD panel for computer, the above- mentioned program is to be included into the microcomputer inherently furnished into the computer.
• a local discharge should be performed by supplying the electric discharging power to a portion of the discharging electrodes as required for securing the effects of power saving, lighting or advertising.
• the switching controller is embodied by the microcomputer in the above embodiments, it is possible to incite the full discharge as well as the local discharge in diverse ways.
• the flat light source capable of obtaining an uniform radiating distribution is manufactured without being limited to the size with respect to the light emitting area.
• the discharging path is moved in a manner to utilize the gas ambient formed by the previous discharging operation throughout the interior of the discharging bulb with the purpose of obtaining a high efficiency light source without requiring the re-starting operation within the discharging bulb.
• the present invention can be applied to manufacture a light source of an optional shape as well as the flat type one.
• the present invention eliminates the need to have additional means such as the light guiding plate or light diffusing plate when being applied as the backlight of the display panel that employs a passive device such as LCD. Also, it allows the local light emission as required to obtain the effect of power saving, and so on.
• the flat light source of the both-sided light emitting type may be useful as the backlight of the panel when the panel is viewed from both sides.
• the discharging bulb according to the present invention in the form of the flat light source to be employed as a light source for general lighting, the dazzling and glaring effects are reduced while the illumination is uniformly distributed across a subject plane.
• it is a very advantageous light source for illumination.

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• 1999
  • 1999-11-12 KR KR1019990050382A patent/KR20010046569A/ko not_active Application Discontinuation
• 2000
  • 2000-11-09 WO PCT/KR2000/001286 patent/WO2001039245A1/en active Application Filing
  • 2000-11-09 AU AU15587/01A patent/AU1558701A/en not_active Abandoned

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