KR200352755Y1 - Flat fluorescent lamp - Google Patents

Abstract

The present invention relates to a flat plate fluorescent lamp having a stable discharge and luminance uniformity, the front plate 110 to which the phosphor 111 is coated; A back plate 170 including a reflector 120, a first electrode 130 and a second electrode 140 printed to be electrically insulated, a dielectric layer 150, and a phosphor 160; It consists of a support portion 180 for supporting the front plate 110 and the back plate 170 to maintain the airtight, the first electrode 130 and the second electrode 140 is a pair of strips, respectively Leads 131 and 141 constitute the same electrode, and a plurality of protrusions P are formed to protrude symmetrically from each other in the pair of strip leads, so that the first electrode portion and the second electrode portion alternate with each other. Since the two electrodes driven by the AC power supply are composed of a pair of strip leads to have the same electrode structure, the number of discharges in the two electrodes can be increased in comparison with the conventional DC power supply, and the brightness and uniformity are increased. There is an advantage that is improved.

Description

Flat fluorescent lamp

The present invention relates to a flat fluorescent lamp, and to a flat fluorescent lamp having a stable discharge and brightness uniformity.

BACKGROUND OF THE INVENTION As a related art for a flat fluorescent lamp, there is disclosed a flat discharge fluorescent lamp having a planar fluorescent lamp having a counter electrode arrangement and a planar fluorescent lamp having a linear arrangement of linear electrodes. In addition, commercially available flat fluorescent lamps include flat fluorescent lamps using a dielectric barrier discharge of Osram, Germany.

7 is a view showing a cross-sectional structure of a conventional fluorescent lamp of the opposite electrode arrangement, the front panel portion 10 and the rear panel portion 20 is fixed by the support frame 30 so that a discharge space is formed. Inert gas is filled in the discharge space.

The front panel portion 10 is formed by stacking the transparent electrode layer 11, the front glass substrate 12, and the front phosphor layer 13 in order.

The rear panel 20 is formed by stacking the rear glass substrate 21, the electrode layer 22, the dielectric layer 23, and the rear phosphor layer 24 in this order.

In the conventional counter electrode arrangement type flat fluorescent lamp, the phosphor layers 13 and 24 are disposed on the front panel portion 10 and the rear panel portion 20 to efficiently convert ultraviolet rays emitted during discharge into visible light. There is a characteristic to convert. However, since electrons and cations generated during gas discharge directly collide with the phosphor, the lifetime of the fluorescent lamp is shortened by sputtering of the phosphor layer by these electrons and cations, and thus there is a problem that the luminance uniformity is lowered.

Next, FIG. 8 is a view showing another example of a conventional flat fluorescent lamp, and shows a surface discharge fluorescent lamp in which a linear electrode is disposed on one side. The fluorescent lamp of FIG. 8 is provided with a supporting frame 60 such that a discharge space is formed between the front panel portion 40 and the rear panel portion 50, and an inert gas is filled in the discharge space.

The front panel portion 40 is composed of a front glass substrate 42 on which the phosphor layer 41 is applied to the bottom surface.

On the rear panel 50, the rear glass substrate 51, the linear electrodes 52, and the linear electrodes 52 are electrically insulated, and a dielectric layer 53 for lowering the discharge start voltage is sequentially stacked.

As described above, in the flat fluorescent lamp having the linear electrodes disposed on one side, the electrodes are disposed on one glass substrate, unlike the fluorescent lamp of FIG. In such a single-sided arrangement of the linear electrodes, since electrons and cations do not directly collide with the phosphor layer, sputtering of the phosphor layer 41 and the linear electrode 52 is prevented, and thus there is an advantage of extending the life of the lamp.

However, such a flat fluorescent lamp uses a linear electrode, which causes a high lighting voltage and high power consumption. In addition, since the linear electrode must be composed of two electrodes having different poles per lamp, in a large area lamp, there is a problem that the distance between the electrodes is increased, the discharge start voltage is increased, and safety of discharge is not secured.

9 and 10 show another example of a conventional planar fluorescent lamp. The fluorescent lamp and the basic discharge concept of FIG. 7 are the same, and a flat fluorescent lamp for dielectrically disturbed discharges is formed by pairing anode electrodes. Show the lamp.

The fluorescent lamp of FIG. 9 is provided with a support frame 90 such that a discharge space is formed between the front panel portion 70 and the rear panel portion 80, and an inert gas is filled in the discharge space.

The front panel portion 70 is composed of a front glass substrate 72 on which the phosphor layer 71 is applied to the bottom surface.

The rear panel 80 has a rear glass substrate 81, a linear electrode 82, a dielectric layer 83 for electrically insulating the linear electrode 82 and lowering a discharge start voltage, and then a phosphor layer 84 in this order. Are stacked.

FIG. 10 is a view illustrating a planar structure of a linear electrode provided in the fluorescent lamp of FIG. 9. The linear electrode 82 is configured of an anode 82a and a cathode 82b and driven by a DC impulse method.

The anode 82a and the cathode 82b are each composed of a plurality of strip leads, in particular the anode 82a is composed of a pair, and one cathode strip 82b is most adjacent to the pair of anodes 82a. The lid is placed. A plurality of needle-shaped protrusions for partial discharge are formed in the cathode strip lead.

In the conventional flat fluorescent lamp, when a DC impulse is applied to the anode 82a and the cathode 82b, a delta partial discharge is formed between the projection P of the anode strip lead and the cathode strip lead. This occurs and visible light is emitted.

However, such a conventional flat fluorescent lamp has a cathode structure having a different electrode structure because a cathode made of a pair of strip leads and an anode made of one strip lead with a plurality of protrusions protruding from each other. The problem of inferior luminance uniformity occurs.

That is, there is a problem in that the portion where the discharge is started and the portion where the discharge is not concentrated in the cathode show a large difference in luminance.

The present invention is to solve the above drawbacks, the present invention is to provide a flat fluorescent lamp having two electrodes having the same electrode structure, and driven by an AC power source having a stable discharge and a uniform luminance distribution.

1 is a perspective view of a portion of a flat fluorescent lamp of the present invention;

2 is a preferred electrode structure of the flat fluorescent lamp of the present invention

Drawing showing an example,

Figure 3 is a preferred of the spacer provided in the flat fluorescent lamp of the present invention

Drawing showing an example,

4 is a view showing another preferred example of the flat fluorescent lamp of the present invention,

Figure 5 is a preferred circuit of the drive circuit for driving the flat fluorescent lamp of the present invention

Drawing showing an example,

6 is a view illustrating waveforms of input and output signals of the driving circuit of FIG. 5;

7 to 10 are views showing various examples of a conventional flat fluorescent lamp.

<Explanation of symbols for the main parts of the drawings>

110: front panel 120: reflector

130: first electrode portion 131: strip lead (first electrode portion)

140: second electrode portion 141: strip lead (second electrode portion)

150: dielectric layer 160: phosphor

170: rear plate 180: support

200: spacer P: protrusion

The flat fluorescent lamp of the present invention is a front plate coated with a phosphor; A back plate provided with a reflector, a first electrode portion and a second electrode portion printed to be electrically insulated, a dielectric layer, and a phosphor; It consists of a support for supporting the front plate and the back plate to maintain the airtight, the first electrode portion and the second electrode portion is a pair of strip leads each constitute the same electrode, the pair of strip leads outside A plurality of projections are formed to protrude symmetrically to each other in the direction, the first electrode portion and the second electrode portion is achieved by alternately arranged.

1 to 6 are related to the flat fluorescent lamp of the present invention, Figure 1 is a perspective view of a portion of the flat fluorescent lamp of the present invention, Figure 2 is an electrode structure provided in the flat fluorescent lamp of the present invention Figure 3 is a view showing a preferred example, Figure 3 is a view showing a preferred example of the spacer provided in the flat fluorescent lamp of the present invention, Figure 4 is a view showing another preferred example of the flat fluorescent lamp of the present invention, Figure 5 is a view showing a preferred example of the driving circuit for driving the flat fluorescent lamp of the present invention, Figure 6 is a view showing the waveform of the input and output signals of the driving circuit of FIG.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a flat fluorescent lamp according to the present invention, the present invention is the front plate 110, the back plate 170, and the discharge space is formed between the front plate 110 and the back plate 170 It is composed of a support 180 provided to be.

The phosphor 111 is coated on the lower surface of the front plate 110 to form a light emitting surface of light generated by the fluorescent lamp.

The back plate 170 includes a reflecting plate 120, first and second electrode portions 130 and 140, a dielectric layer 150, and a phosphor 160.

The reflector 120 disposed on the upper surface of the rear panel 170 reflects light toward the light exit surface to increase light utilization efficiency, and adjusts the amount of reflection of the entire incident light so that the entire light exit surface of the backlight has a uniform luminance distribution. do.

The first and second electrode parts 130 and 140 are printed on the upper surface of the reflector 120 to be electrically insulated from each other.

The dielectric layer 150 electrically insulates the first and second electrode portions 130 and 140 and limits the current.

The phosphor 160 is coated on the top of the dielectric layer 150.

An inert gas is filled in the discharge chamber including the front plate 110, the back plate 170, and the support 180, but preferably does not contain mercury. Specifically, argon (Ar), or neon (Ne) or krypton (Kr) gas including xenon (Xe) gas or xenon (Xe) gas may be filled.

In the present invention, in order to maintain uniform luminance characteristics, the height between the front plate and the back plate should be kept constant. If this gap is not maintained, the non-light emitting area is generated in the micro discharge of the strip lead, and this is compensated for. In order to achieve this, the fluorescent lamp preferably has a thickness of 3 mm or more, and in the present invention, more preferably, the distance between the front plate and the rear plate has a range of 3 to 8 mm.

2 is a view showing a preferred example of the electrode structure provided in the flat fluorescent lamp of the present invention, the first electrode portion 130 and the second electrode portion 140 according to the present invention are each a pair of strip lead ( 131 and 141 constitute the same electrode, and the pair of strip leads 131 and 141 are formed to protrude symmetrically from each other in the outward direction, so that the first electrode 130 and The second electrode unit 140 is characterized in that they are arranged alternately.

The plurality of first electrode portions 130 and the second electrode portions 140 are respectively connected to the main electrodes 132 and 142 provided outside the discharge chamber. Since the main electrodes 132 and 142 do not greatly affect discharge characteristics or electrical effects generated in the discharge chamber, the shape of the main electrodes in the present invention is not limited to a specific shape.

The protrusions P are preferably formed on the strip leads 131 and 141 with equal intervals between them.

On the other hand, in the present invention, the end of each strip lead 131, 141 is characterized in that it is located outside the inner contact boundary line between the back plate 170 and the support.

Reference numeral 180a of FIG. 2 denotes an area in which the support part is fixed, and ends of each strip lead 131 and 141 extend to at least a part where the support part is fixed.

This allows the end of the strip lead to be located outside the discharge space, so that the end of the strip lead does not affect the discharge generated in the discharge chamber, thereby obtaining stable discharge characteristics. In other words, the end portion and the middle portion of the strip lead can be prevented from being discharged in different discharge modes to obtain the same luminance uniformity between the center and the edge of the lamp.

In the present invention, the protrusions formed on each strip lead have needle-shaped symmetry.

Referring to the enlarged partial view shown in FIG. 2, it is preferable that the tip P1 of the protrusion P has a constant curvature. The curved tip P1 has the disadvantage of increasing the discharge start voltage, but it can widen the discharge path by widening the effective area of the discharge and reducing the concentration of the electric field, and can solve the heat generation problem formed by the instantaneous arc. There is an advantage that can extend the life of the lamp.

In addition, not only the tip P1 of the protrusion but also the middle part P2 and the lower part P3 of the protrusion may have a constant curvature, thereby preventing discharge from occurring at a portion other than the tip P1 portion of the protrusion. have.

It is preferable that the curvature of the curve formed in the protrusion is in the range of R0.1 to R0.8.

Next, the spacing between the adjacent strip leads of the first electrode portion and the second electrode portion should be properly maintained. That is, when the distance between the strip leads between the first electrode portion and the second electrode portion is too narrow, the discharge start voltage can be lowered, but the discharge current increases rapidly, resulting in a low discharge efficiency. On the other hand, when the distance between strip leads is enlarged, a discharge start voltage becomes high and a non-light emitting area may arise. Therefore, the spacing between electrodes to be appropriate is of great importance in determining the brightness and efficiency and the performance of the inverter.

In the present invention, the distance d1 between the adjacent strip leads 131 and 141 of the first electrode part 130 and the second electrode part 140 is 2 to 10 mm.

Next, the spacing between the pair of strip leads constituting the same electrode is preferably kept to a minimum distance, and when the spacing between strip leads constituting the same electrode is large, the non-light emitting area is increased and luminance uniformity is increased. Can fall.

In the present invention, the interval d2 between the pair of strip leads constituting the same electrode is characterized by being 1 to 7 mm.

In addition, in the present invention, the width of the strip lead is characterized in that 0.1 to 1mm.

In the flat fluorescent lamp of the present invention, since the pressure difference between the inside and the outside of the discharge chamber is large, a spacer that can support the front plate and the back plate may be additionally configured, and such spacers may have uniform luminance by minimizing shading. It is preferable to prevent the fall.

3 is a view showing a preferred example of the spacer provided in the flat fluorescent lamp of the present invention, a spacer 200 consisting of a cube 210 and a sphere 220 between the front plate 110 and the rear plate 170. May be added.

The ratio of the cube 210 to the sphere 220 is preferably manufactured to a size that can minimize the disturbance of uniformity and brightness. In addition, phosphors 211 and 221 are coated on the surfaces of the hexahedron 210 and the sphere 220 so as to increase luminous efficiency.

4 is a view showing another preferred example of the flat fluorescent lamp of the present invention, the heat radiation member may be further configured on the rear plate to facilitate the heat dissipation excellent.

The heat dissipation member may include a heat dissipation sheet or silicon mounted on the rear surface of the back plate 170 to quickly conduct heat.

In addition, the flat fluorescent lamp according to the present invention is further provided with a light diffusing member on the top of the front plate to compensate for the effect of the difference in brightness between the micro-discharge region between different electrodes to increase the brightness and increase the uniformity. .

The light diffusion member includes a diffusion sheet 410 or a prism sheet 420.

The flat fluorescent lamp of the present invention is characterized by being driven by a square wave AC pulse power supply.

Since the polarity of the AC pulse power source assumes the same role, the polarity of the first electrode part and the second electrode part is not distinguished.

5 is a view showing a preferred example of a driving circuit for driving a flat fluorescent lamp of the present invention, by combining four high-speed FETs and a transformer to output a high-voltage square wave AC pulse.

That is, an appropriate signal is input to the gate of each FET while DC voltage (+ V) is applied to the drains of Q1 and Q3 to obtain a square wave AC pulse. Referring to FIG. 6A, when Q3 and Q4 are simultaneously 'on', voltages are generated approximately '+ V' at both ends of the primary side of the transformer, and when Q1 and Q2 are simultaneously 'on', 1 Both ends of the vehicle generate a voltage approximately '-V'.

6 (a) and 6 (b) show waveforms of the gate input signal and the output voltage of the driving circuit of FIG. 5, respectively. The output voltage generated at the primary side of the transformer is boosted and applied through the first electrode part and the second electrode part.

In the planar fluorescent lamp of the present invention configured as described above, when a square wave AC pulse is applied to the first electrode part 130 and the second electrode part 140 by a driving circuit, the first electrode part 130 and the second electrode part are provided. A partial discharge is generated between the strip leads 131 and 141 of the 140 through the protrusion P.

The free electrons generated by the partial discharges generated between the strip leads excite the xenon (Xe) atoms charged in the discharge chamber, and the excited xenon atoms emit ultraviolet (UV) light and are ground state. Becomes

Ultraviolet (UV) light emits visible light by reacting with the phosphors 111 and 160 coated on the front plate 110 and the back plate 170, respectively.

[Table 1] below compares the characteristics of the conventional flat fluorescent lamp and the flat fluorescent lamp of the present invention.

Conventional This invention Luminance uniformity 85% 93% Luminance (cd / m2) 5,900 6,500 Luminous Efficiency (Im / W) 25 28 Life (hrs) 50,000 70,000

It can be seen that the flat fluorescent lamp of the present invention is superior in luminance uniformity, brightness and luminous efficiency as compared with the prior art, and also has a longer life than the conventional flat fluorescent lamp.

In the flat fluorescent lamp of the present invention, since two electrodes driven by an AC power supply have a pair of strip leads to have the same electrode structure, the number of discharges from the two electrodes is increased in comparison with the conventional DC power supply. It can be made, there is an advantage that the brightness and uniformity is improved.

Further, needle-like protrusions having a constant curvature are formed on the strip leads of each electrode, so that the start of discharge and the path of discharge can be determined in advance, so that stable discharge can be generated.

Claims (16)

A front plate coated with a phosphor; A reflecting plate, a first electrode portion and a second electrode portion printed to be electrically insulated, a dielectric layer, and a back plate provided with a phosphor; It consists of a support for maintaining the airtight and the front plate and the back plate, Each of the first and second electrode portions has a pair of strip leads forming the same electrode, and a plurality of protrusions protrude symmetrically from each other in an outward direction on the pair of strip leads. The planar fluorescent lamp of claim 2, wherein the second electrode parts are alternately arranged. The flat fluorescent lamp of claim 1, wherein the protrusion is needle-shaped in symmetry. The flat type fluorescent lamp of claim 2, wherein the tip of the protrusion is curved. The flat fluorescent lamp of claim 2, wherein a tip and a bottom of the protrusion are connected in a curved line. The flat fluorescent lamp of claim 2, wherein the lower end of the protrusion and the strip lead are connected in a curved line. The flat fluorescent lamp according to any one of claims 3 to 5, wherein the curvature of the projection curve is in the range of R0.1 to R0.8. The flat fluorescent lamp of claim 1, wherein a distance between the pair of strip leads constituting the same electrode is 1 to 7 mm. The flat fluorescent lamp of claim 1, wherein a distance between the first and second electrode strips adjacent to the strip leads is 2 to 10 mm. The flat fluorescent lamp of claim 1, wherein the protrusions formed on the strip lead are formed at equal intervals. The flat fluorescent lamp of claim 1, wherein an end portion of the strip lead is located outside the inner contact boundary between the back plate and the support. The flat fluorescent lamp of claim 1, wherein a distance between the front plate and the rear plate is 3 to 8 mm. The flat fluorescent lamp of claim 1, further comprising a spacer formed of a cube and a sphere coated with a phosphor between the front plate and the back plate. The flat fluorescent lamp of claim 1, wherein a heat dissipation member is further attached to a rear surface of the rear plate. The flat fluorescent lamp of claim 1, wherein a light diffusion member is further attached to an upper portion of the front plate to increase uniformity. The flat fluorescent lamp of claim 1, wherein an AC power is applied to the first electrode part and the second electrode part. 16. The flat fluorescent lamp of claim 15, wherein the AC power source is a square wave pulse.