JP2006147251A - Flat discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat discharge lamp having high light transmissivity and high luminous efficiency. <P>SOLUTION: A discharge electrode 46 provided at a light emitting side is configured with a narrow conductor film formed by uniform repetition of a structure having an opening 48 in which the ratio of the area of the opening is large enough to range from 90 to 99%, and having a conductor 50 which has a line width narrow enough to range from 15 to 50 μm. As light generated in an airtight space 18 is emitted through the opening 48, high light transmissivity can be obtained according to the ratio of the area of the opening, even if the conductor has no light transparency. Moreover, while a sheet resistance is increased in accordance with raising the light transmissivity, the luminous efficiency does not decrease. Since the opening 48 is formed with a constant spacing W, the conductor 50 has a uniform and repeated structure. Therefore, even if the conductor 50 has property of shading light, light can be emitted from the entire surface of the flat discharge lamp almost uniformly, and unevenness quality of display can be obtained as a result. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flat discharge lamp, and more particularly to improvement of a discharge electrode provided on a front plate side which is a light emission side.

  A light transmitting front plate, a back plate forming a flat airtight space between the front plate (hereinafter referred to as a substrate unless otherwise specified), and for generating a discharge in the airtight space. The front plate and the back plate are provided on the front plate and the back plate so as to face each other and are covered with a dielectric layer, and the front plate emits light generated by discharging in the hermetic space. There is known a flat type discharge lamp that emits through a gas (see, for example, Patent Documents 1 to 4). Such a flat discharge lamp is a backlight for irradiating from the back side of a transmissive liquid crystal panel, an illumination lamp for irradiating both or one side from the inside of a guide display board or an advertisement display board, or a ceiling. It is used in flat fluorescent lamps for general lighting that are directly attached to a wall or the like.

In particular, according to what is the opposite discharge structure between the front plate and the back plate as described above, for example, as described in Patent Document 5, as compared with the discharge electrode provided only on the back plate, The uniformity of discharge in the surface of the front plate which is the light emission surface is increased. Therefore, there is an advantage that uniform luminance can be obtained over the entire effective area of the front plate.
Japanese Patent No. 3481721 JP-A-3-110750 Japanese Patent Laid-Open No. 7-21948 Japanese Patent Laid-Open No. 6-176736 JP-A-6-231731

By the way, since the flat type lamp having a counter discharge structure between the front plate and the back plate emits light from the front plate side as described above, conventionally, a material transparent to the light, for example, visible light is used. A transparent conductor material that transmits light with high transmittance is provided on the entire surface of the front plate to constitute the front electrode. As such transparent conductor materials, indium tin oxide (ITO), tin oxide (SnO ₂ ) and the like are known. In these transparent conductor materials, the sheet resistance value and the visible light transmittance are in a trade-off relationship, and the visible light transmittance is lowered when the sheet resistance value is lowered. Therefore, it has been attempted to increase the visible light transmittance at the expense of conductivity, but even if it is formed with a relatively high sheet resistance value of, for example, about 200 (Ω / □), the visible light transmittance is at most 85. It stayed at ~ 90 (%). Even in the case of low conductivity as described above, in a normal use mode, the applied voltage is relatively high on the order of kV, and since there is little current, there is almost no voltage drop, so the luminance is lowered at the inner periphery. Such inconvenience does not occur, and a sufficiently high average surface luminance can be obtained (that is, there is no problem in display quality). However, when the sheet resistance value is large, there is a problem in that the power loss increases, the light emission efficiency decreases, and the heat generation amount increases. Further, since the light transmittance of the transparent electrode material has wavelength dependency, there is a problem that the transmitted light is colored when light over a wide wavelength region such as white light is transmitted. Such a problem is not limited to the case of visible light, but also occurs at other wavelengths where a flat discharge lamp is used, such as ultraviolet rays and infrared rays.

  For example, in Patent Document 1, the sheet resistance value, the light emission area, and the discharge distance are determined so as to satisfy a certain relationship, thereby increasing the visible light transmittance while suppressing a decrease in the light emission efficiency. It is described. However, this is merely an optimization based on the above trade-off relationship, and the above-described problems caused by using the transparent electrode material are not solved at all.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a flat discharge lamp having high light transmittance and high luminous efficiency.

  In order to achieve such an object, the gist of the present invention is that a translucent front plate, a back plate that forms a flat airtight space between the front plate, and a discharge in the airtight space. Light generated by discharging in the hermetic space of the front plate and the back plate on the front plate and the back plate and facing each other and coated with a dielectric layer. In which a plurality of openings having a predetermined shape are formed at 90 to 99 (%) of a total area with a constant mutual spacing within a range of 15 to 50 (μm). ), And the front side electrode is formed of a conductor film having a uniform repetitive shape in which the narrow-width conductor portions are provided in an area ratio within the range of (2).

  In this way, in the flat discharge lamp of the type in which the counter discharge is performed between the back plate and the front plate, the front side electrode provided on the light emission side has an area ratio of the opening, that is, an opening ratio of 90 to 99. (%) Is sufficiently large and the line width is 15 to 50 (μm), and a sufficiently thin conductor portion is formed of a conductor film formed in a uniform repetitive shape. Therefore, since the light generated in the hermetic space is emitted through the opening, high light transmittance corresponding to the aperture ratio can be ensured even if the conductor does not have translucency. Further, since the light-transmitting property is not required for the conductor, an appropriate conductor material capable of sufficiently reducing the sheet resistance value can be used regardless of whether it is opaque or transparent. The value does not increase so that the light emission efficiency does not decrease or the heat generation amount does not increase. In addition, the said opening part which is a part in which a conductor does not exist is not restricted to the thing of the closed shape, For example, the thing etc. which open | release both ends and comprise a strip | belt shape are included.

  At this time, since the openings are provided with a certain mutual interval, the conductor portion (the portion of the conductor film where the conductor exists, that is, the portion other than the opening portion) has a uniform repetitive shape. Even if it has the property, light is emitted almost uniformly from the entire surface, and as a result, display quality with less unevenness is obtained as in the case where a transparent electrode material is used on the entire surface. In addition, since light is emitted exclusively from the inside of the opening where no conductor exists, the problem of the wavelength dependency of the transmittance as in the case of transmitting through the transparent electrode cannot occur. In addition, since the conductor portion is sufficiently thin with a line width of 50 (μm) or less, the conductor portion is repeated so that uneven luminance is sufficiently suppressed while ensuring a high aperture ratio as described above. The density (that is, the number of repetitions of the conductor part and the opening per unit area) can be increased and the conductor part is not conspicuous, while the line width is sufficiently thick as 15 (μm) or more, so that the disconnection extension Therefore, luminance unevenness due to partial unlighting is sufficiently suppressed. Therefore, a flat discharge lamp having sufficiently high light transmittance and sufficiently high luminous efficiency can be obtained.

  The discharge electrode pair needs to have opposite surfaces, that is, discharge surfaces covered with a dielectric layer, but the arrangement surface may be the inner surface or the outer surface of either the front plate or the rear plate. Absent. One may be provided on the inner surface and the other may be provided on the outer surface. In the case of being provided on the inner surface, it is essential to provide a dielectric layer separately. However, in the case of being provided on the outer surface, the front plate or the back plate functions as a dielectric layer, which is useless. That is, the “dielectric layer” referred to in the claims may be constituted by a front plate or a back plate as long as it substantially functions as such with respect to the discharge electrode.

  Here, preferably, the conductor film has a net shape. In this way, since the conductor portion is formed so as to be continuous in a plurality of directions, the uniformity of luminance is further improved, and the possibility of partial unlighting due to disconnection is further reduced.

  Preferably, each of the plurality of openings has a regular hexagonal shape with a diameter of an inscribed circle in a range of 0.5 to 2.5 (mm), and the conductor film includes the conductor portion. Is bent along the outer peripheral edge of the plurality of openings with a certain width dimension, thereby forming a honeycomb shape as a whole. In this way, the openings that form a regular hexagon are closely spaced from each other by the width of the conductor, and the conductor is bent and formed with a certain width, so the conductor is a straight line. Compared to the configuration, there is an advantage that display quality can be improved by suppressing interference fringes (moire) without increasing the light shielding area. In addition, the regular hexagonal shape has an inscribed circle with a diameter of 0.5 to 2.5 (mm), so it is possible to secure a sufficient aperture ratio to obtain high brightness and uniformity. High discharge is obtained and luminance unevenness is suppressed. If the diameter of the inscribed circle is less than 0.5 (mm), it will be difficult to ensure a sufficiently large aperture ratio while ensuring the line width of the conductor, and if it exceeds 2.5 (mm), the discharge will be biased and extended. In this case, light emission unevenness is likely to occur.

  Preferably, each of the plurality of openings has a rectangular shape with a short side having a size within a range of 0.5 to 2.5 (mm), and the conductor film has a constant width. By being provided along the outer peripheral edge of the plurality of openings with dimensions, the overall shape is a lattice shape or a ridge shape. In this way, the mutual interval between the conductor portions is set to an appropriate size as in the case of the regular hexagon described above, so that a sufficient aperture ratio can be secured and high luminance can be obtained.

  Preferably, the conductor portion has a plurality of linear portions that extend along one direction and are arranged with a mutual interval within a range of 0.5 to 2 (mm). In this way, the mutual interval between the conductor portions is set to an appropriate size as in the case of the regular hexagon described above, so that a sufficient aperture ratio can be secured and high luminance can be obtained.

  In the above aspect, more preferably, the conductor film is provided with a plurality of connecting portions in the longitudinal direction for connecting the linear portions adjacent to each other. In this way, there is an advantage that partial unlighting due to disconnection is less likely to occur as compared with the case where the linear portions are connected to each other only at both ends thereof. More preferably, the connecting portions are provided on both sides in the width direction of the individual linear portions at positions different from each other in the longitudinal direction. That is, for example, it is provided in a candy shape. In this way, there is an advantage that interference fringes are less likely to occur as compared with the case where the connecting portions are continuous in the longitudinal direction.

  Preferably, the flat discharge lamp includes a plurality of longitudinal spacers extending along a predetermined direction between the front plate and the back plate, and the plurality of openings are formed on the spacers. They are arranged along a direction inclined at a predetermined angle of less than 90 degrees with respect to the longitudinal direction. In this way, there is an advantage that interference fringes are suppressed based on the relationship with the spacer arrangement pitch.

  The conductor film can be formed by various methods, and the lower limit value of the film thickness is determined according to the constituent material and the film forming method so as to ensure necessary conductivity and continuity. For example, when formed by etching an aluminum thin film, the conductor film is provided with a thickness of 0.5 (μm) or more. In this way, a conductor film having sufficient conductivity can be formed with high reliability. In addition, the lower limit when formed by thick film etching is, for example, about 5 (μm). On the other hand, the upper limit of the thickness dimension of the conductor film is not particularly limited in terms of function, but, for example, 10 (μm) or less is preferably used. However, since there is a preferable value depending on the film forming method, the upper limit value is preferably in the range of about 0.5 to 1.5 (μm) when etching an aluminum thin film, and 5 to 5 when forming by thick film etching. A range of about 7 (μm) is preferable.

  In the present invention, the light generated in the airtight space is not limited to visible light, and may be light that cannot be captured with the naked eye, such as ultraviolet rays and infrared rays. The “front plate having translucency” referred to in the claims means that light generated in the airtight space can be transmitted, and is not necessarily limited to that capable of transmitting visible light.

  The airtight space is not limited to a flat front plate side and a back plate side as long as the flat space can constitute a flat discharge lamp. For example, those having irregularities on the inner surface of the back plate or the front plate for the purpose of light scattering are also included in the “flat airtight space” referred to in the claims.

  In addition, the present invention is preferably applied to a flat discharge lamp having a phosphor layer and exciting the phosphor layer with ultraviolet light generated by discharge to emit light, but a mercury lamp not having a phosphor layer, The present invention is similarly applied to a flat discharge lamp to which another type of discharge lamp such as a sodium discharge lamp or a neon lamp is applied. When the phosphor layer and the spacer are provided, the phosphor layer may be provided also on the side surface of the spacer.

  Further, the front plate and the back plate for forming the airtight space are made of, for example, a glass material, but when the light is not emitted from the back plate side, the back plate does not need to have translucency, It can also be made of an opaque material such as ceramics or a bag.

  In addition, since the back side electrode is located on the side opposite to the light emission direction, the constituent material and the planar shape thereof are determined regardless of the light transmittance. For example, an opaque material may be used to provide the entire surface in a solid shape, or an appropriate perforated shape.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a plan view for explaining the configuration of a flat discharge lamp 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA. The flat discharge lamp 10 is classified as a cold cathode tube in which, for example, xenon gas is used as a discharge gas, does not contain harmful mercury, and has a response that rises in the order of msec at all temperatures. Yes. Such a flat discharge lamp 10 is used as a backlight of a liquid crystal panel constituting a display device such as a liquid crystal television or a car navigation system.

  In FIG. 1 and FIG. 2, the flat discharge lamp 10 has a thin flat box shape as a whole because the back plate 12 and the front plate 14 are arranged in parallel to each other with a slight gap therebetween. . Each of the back plate 12 and the front plate 14 is made of a glass plate made of soda lime glass having a thickness of about 0.7 to 1.1 (mm) and a size of about 250 × 160 (mm), for example. These are fixed airtightly to each other via a side wall 16 made of, for example, soda lime glass provided substantially in a rectangle along the peripheral edge portion, and a rectangular airtight space 18 is formed between them. In this airtight space 18, xenon or a mixed gas containing xenon as a main component (for example, xenon 90 (%), argon 10 (%)) is at a pressure of about 40 (kPa) (≈300 (Torr)), for example. It is enclosed. The gas pressure of the sealed gas, that is, the discharge gas, is determined so that a substantially uniform discharge is generated over the entire surface of the hermetic space 18.

  Further, a plurality of longitudinal spacers 20 are provided between the back plate 12 and the front plate 14 in order to keep their mutual distance constant. The spacer 20 is made of, for example, soda lime glass similar to the back plate 12 and the front plate 14. Each of the spacers 20 has a triangular prism shape with a right-angled isosceles triangle cross section, and one side surface corresponding to the oblique side opposite to the right angle faces the inner surface 22 side of the back plate 12 and extends along the short side of the back plate 12. They are arranged on the inner surface 22 in parallel and with a uniform center spacing. That is, the spacers 20 each have a shape in which the width dimension in the direction perpendicular to the longitudinal direction decreases linearly from the back plate 12 toward the front plate 14. For this reason, the front plate 14 is supported at a ridge (or ridgeline) having a very narrow width (for example, substantially zero) opposite to the oblique side of the spacer 20.

  Further, both ends in the longitudinal direction of the spacer 20 are positioned slightly on the inner peripheral side with respect to the inner peripheral surface 24 of the side wall 16, and a gap of about 5 (mm), for example, exists between them. The airtight space 18 is substantially partitioned into a plurality of discharge spaces extending along the short side of the back plate 12 by the plurality of spacers 20, but is not completely divided spatially, and the gap Through each other. In FIG. 1, reference numeral 26 denotes an exhaust hole provided for exhausting air from the airtight space 18 after the back plate 12 and the front plate 14 are sealed. The exhaust hole 26 is hermetically sealed, for example, by fixing an exhaust pipe (not shown) or by sealing glass or the like.

  FIG. 3 is an enlarged view of a part on the left end side of FIG. 2 to explain the configuration of the flat discharge lamp 10 in more detail. The spacer 20 is configured, for example, so that the width of the hypotenuse is about w = 2 (mm), the height is about h = 1 (mm), and the base angle θ is about 45 degrees in the cross section shown in the drawing. Moreover, the center space | interval of the adjacent spacer 20 is about p = 6 (mm), for example. Since the height dimension of the side wall 16 is substantially the same as that of the spacer 20 and slightly lower than that, the height dimension of the hermetic space 18 is determined by the height dimension of the spacer 20 (1 mm). It is about. Moreover, the mutual space | interval in the lower end position by the side of the backplate 12 of the spacer 20 is about 4 (mm), for example. These numerical values are determined according to the area, gas pressure, and the like so as to obtain as uniform a discharge as possible in the airtight space 18.

  The spacer 20 is airtightly fixed to the inner surface 22 of the back plate 12 and the side wall 16 is airtightly fixed to the back plate 12 and the front plate 14 by inorganic bonding agent layers 28 and 30, respectively. The inorganic bonding agent layer 28 is made of a low-melting-point glass having a sufficiently lower softening point than the glass constituting the back plate 12, the spacer 20, and the like. Further, as shown in the manufacturing method described later, since the joining with the front plate 14 is separately performed after the joining of the back plate 12 with the side wall 16 and the spacer 20, the inorganic material used for joining the front plate 14 is used. The bonding agent layer 30 is made of frit glass or the like having a softening point lower than that of the inorganic bonding agent layer 28.

  Further, for example, a phosphor layer 34 is provided with a thickness of about 25 to 50 (μm) on the inner peripheral surface 24 of the side wall 16, the side surface 32 of the spacer 20, and the back plate inner surface 22. Further, a phosphor layer 38 made of a similar phosphor is also provided on the inner surface 36 of the front plate 14 with a thickness dimension of about 3 to 10 (μm), for example, which is sufficiently thinner than the phosphor layer 34. That is, the inner surface of the airtight container constituting the airtight space 18 is substantially entirely covered with the phosphor layers 34 and 38. These phosphor layers 34 and 38 are white phosphors formed by mixing phosphors that emit light in red, green, and blue colors when excited by ultraviolet rays, for example. Alternatively, one of the above phosphors of each color may be used alone or in a mixture of two, and used in an appropriate emission color such as daylight. Alternatively, a phosphor that generates ultraviolet rays can be used.

  Further, a discharge electrode 42 is provided on the back surface 40 of the back plate 12, that is, one surface opposite to the front plate 14. The discharge electrode 42 is made of a conductive material such as silver or aluminum, and is provided on the entire surface, for example, by using an appropriate method such as printing, vapor deposition, or sputtering. μm). Further, a discharge electrode 46 is provided on the front surface 44 of the front plate 14, that is, one surface opposite to the back plate 12. In the present embodiment, these discharge electrodes 42 and 46 constitute a discharge electrode pair. Since the back plate 12 or the front plate 14 functions as a dielectric layer for each of them, a dielectric for generating AC discharge is provided. There is no particular layer. In addition, although the lead for energizing is connected to the discharge electrodes 42 and 46, for example by soldering, illustration was abbreviate | omitted.

  FIG. 4 is a plan view showing a part of the discharge electrode 46 on the front plate 14 side as viewed from above in FIG. 3, and FIG. is there. The discharge electrode 46 has a large number of openings 48 each having a regular hexagonal shape with a length L of one side in the range of 0.58 to 1.4 (mm), for example, about 1 (mm). Are arranged at a constant mutual distance along the direction along the vertical direction and the two directions forming 60 degrees and -60 degrees with respect to the longitudinal direction. In the discharge electrode 46, a portion 50 bent between the openings 48 is a conductor film made of a conductive material such as an aluminum thin film or silver, and this portion, that is, the conductor portion 50 actually contributes to the discharge. To do.

  The mutual distance, that is, the width dimension W of the conductor portion 50 is a constant value within a range of 15 to 50 (μm), for example, about 30 (μm). That is, the conductor part 50 has a uniform repeated shape with a certain width dimension. The thickness of the conductor film is, for example, in the range of 0.5 to 1.5 (μm), for example, about 1 (μm). The opening 48 has a diameter of an inscribed circle in the range of 1 to 2.5 (mm), for example, about 1.7 (mm). Therefore, the area ratio occupied by the opening 48 in the discharge electrode 46, that is, the opening ratio of the discharge electrode 46 is a high value in the range of 90 to 99 (%), for example, about 96.6 (%). In addition, the discharge electrode 46 is a unit resistance value when the whole is regarded as a planar constant resistor, that is, a sheet resistance value equivalent value, for example, within a range of 1 to 20 (Ω), for example, about 5 (Ω) is extremely high. It has conductivity.

  In the flat discharge lamp 10 configured as described above, the polarity (positive / negative) between them is periodically reversed between the discharge electrodes 42 and 46 using, for example, a high-frequency inverter circuit or the like, for example, 1.5 (kV ), Applied with a high frequency sine wave or pulse of about 20 (kHz). Note that the frequency and voltage of the drive current, the pulse width in the case of a pulse, and the like are appropriately set according to the size of the flat discharge lamp 10, the sealed gas pressure, and the like. When a so-called field discharge type discharge is generated between the electrodes 20 and 28 by applying a sine wave or a pulse, the discharge gas is ionized and, for example, an ultraviolet ray having a wavelength of about 172 (nm) or 147 (nm). Is generated. Then, the phosphor layer is excited by the ultraviolet rays to emit light, and the light is emitted from the entire surface through the front plate 14.

By driving in this way, according to the present embodiment, light emission with substantially uniform unevenness is obtained over the entire surface of the front plate 14 with a sufficiently high luminance of, for example, about 2000 to 9000 (cd / m ² ). It was. Such high brightness can be obtained because the aperture ratio is as high as 96.6 (%) instead of forming the discharge electrode 46 on the front plate 14 side with a conventional transparent conductor material such as ITO with low translucency. This is because it is composed of a net-like conductor film.

  That is, according to the present embodiment, in the flat type discharge lamp 10 of the type in which the opposite discharge is performed between the back plate 12 and the front plate 14, the discharge electrode 46 provided on the light emission side has an area ratio of the opening 48. Is sufficiently large as 90 to 99 (%), and a sufficiently thin conductor portion 50 with a line width of 15 to 50 (μm) is formed of a narrow-width conductor film formed in a uniform repetitive shape. Therefore, since the light generated in the airtight space 18 is emitted through the opening 48, the conductor is made of aluminum, silver, or the like, so that the light depends on the aperture ratio even if the conductor is not translucent. High light transmittance can be secured. Further, since the light-transmitting property is not required for the conductor, the above-described conductor material having a sufficiently low sheet resistance value can be used, so that the sheet resistance value increases as the light transmittance is increased. Luminous efficiency is not reduced. In addition, since the openings 48 are provided with a constant mutual interval W, the conductor portion 50 has a uniform repetitive shape. Therefore, even if the conductor portion 50 has a light shielding property, it is substantially uniform from the entire surface. A display quality with less unevenness is obtained as in the case where light is emitted and a transparent electrode material is used on the entire surface. Therefore, a flat discharge lamp having sufficiently high visible light transmittance and sufficiently high luminous efficiency can be obtained.

  In addition, according to the present embodiment, since the discharge electrode 46 has a net shape, the conductor portion 50 is continuous in a plurality of directions, so that the uniformity of luminance is further improved and the possibility of partial unlighting due to disconnection is achieved. Is reduced.

  In addition, according to the present embodiment, the resistivity is lower than that in the case where the electrode is made of a transparent conductor material such as ITO, so that there is an advantage that heat generation of the flat discharge lamp is suppressed.

  In addition, according to the present embodiment, since light is emitted from the opening 48 where the conductor portion 50 does not exist, the problem of the wavelength dependency of the transmittance as in the case of transmitting through a transparent electrode such as ITO also arises. I don't get it. That is, when white light is generated in the airtight space 18, there is an advantage that the light is emitted without being colored.

  The flat discharge lamp 10 is manufactured as follows, for example. That is, in the treatment process of the back plate 12, first, the discharge electrode 42 is provided on the back surface 40 by an appropriate method such as vapor deposition or printing. Next, the spacer 20 and the side wall 16 separately manufactured are bonded to the back plate inner surface 22 using, for example, low melting point glass or the like (that is, the constituent material of the inorganic bonding agent layer 28). This step is performed, for example, by applying a low softening point glass paste to the inner surface 22 of the back plate 12 or the bottom surface of the spacer 20, placing it at a predetermined position, drying, and performing a baking treatment.

  Next, the phosphor paste is applied to the inner surface 22 of the back plate, the inner peripheral surface 24 of the side wall, and the side surface 32 of the spacer by thick film screen printing or application by a dispenser, and a drying process is performed. Next, a glass frit for forming the inorganic bonding agent layer 30 is applied using a dispenser and the like, dried, and then fired. Thereby, the phosphor layer 34 and the inorganic bonding agent layer 30 are formed simultaneously.

  On the other hand, in the processing step of the front plate 14, first, the discharge electrode 46 is formed by providing a conductive material on the surface 44 by a thin film process or a thick film process. Next, the phosphor layer 38 is provided by applying a phosphor paste to the inner surface 36 and subjecting it to drying and baking.

  Next, the front plate 14 on which the discharge electrode 46 and the phosphor layer 38 are formed is overlaid on the back plate 12. When an exhaust pipe is attached to the exhaust hole 26, it is bonded at this stage using frit glass or the like. Next, the back plate 12 and the front plate 14 are sandwiched and fixed with a heat-resistant clip or the like through a mica plate or the like, and sealed through a firing furnace. At this time, the gap between the back plate 12 and the front plate 14 is made to match the height of the plurality of spacers 20 formed on the back plate 12 by being sandwiched between the heat resistant clips. Therefore, the mutual distance between the back plate 12 and the front plate 14 is substantially uniform over the entire surface, and further, the mutual distance between the discharge electrodes 42 and 46 provided on them is uniform. As a result, the uniformity of the discharge over the entire surface is enhanced and the uniformity of the brightness is enhanced. And the said flat discharge lamp 10 is obtained by exhausting from the said exhaust hole 26, enclosing and sealing discharge gas.

  The discharge electrode 46 is not limited to the shape described above, and can be formed in various shapes in which the openings are arranged at regular intervals. FIGS. 6 to 10 show an example thereof, and correspond to FIG. 4 respectively.

  The discharge electrode 52 shown in FIG. 6 is provided with a plurality of strip-shaped openings 54 parallel to each other arranged at regular small intervals. Between the openings 54, narrow linear conductors 56 are provided. For example, the width dimension and the thickness dimension of the conductor portion 56 are both the same values as in the above-described embodiment. That is, the width dimension is in the range of 15 to 50 (μm), for example, about 30 (μm), and the thickness dimension is in the range of 0.5 to 1.5 (μm), for example, about 1 (μm). Moreover, the center space | interval of the conductor part 56 is in the range of 0.5-2 (mm), for example, is about 1 (mm). Even in this embodiment, the aperture ratio is about 90 to 99 (%), for example.

  The discharge electrode 58 shown in FIG. 7 has a shape in which the conductor portion 56 is connected to each other at the intermediate portion in the discharge electrode 52. That is, a plurality of rectangular openings 60 are provided side by side in the longitudinal direction and the width direction, thereby forming a net-like conductor portion 62 that is continuous as a whole. The conductor portion 62 is formed so as to extend along two directions, but one extending from the lower left to the upper right in FIG. 7 is provided in a continuous linear shape, while the other extending from the lower right to the upper left is adjacent to each other. It is provided in an intermittent shape provided alternately on one and the other of the two straight lines. That is, the conductor part 62 of the present embodiment has a ridge shape. Therefore, compared with the discharge electrode 52 shown in FIG. 6, there is an advantage that the possibility of partial unlighting due to disconnection is reduced.

  The size of the opening 60 is, for example, in the range of 0.5 to 2 (mm) × 5 to 50 (mm), for example, about 1 × 5 (mm), and the mutual interval in the longitudinal direction and the lateral direction is For example, it is in the range of 15 to 50 (μm), for example, about 30 (μm). That is, also in this embodiment, the line width of the conductor portion 62 is set to a constant value similar to that of the conductor portion 50 described above, and the thickness dimension is also the same. In this embodiment, the aperture ratio is smaller than that shown in FIG. 6 by a size corresponding to the pitch of the intermittent portion, but it has an aperture ratio of approximately 90% or more. Further, according to this configuration, interference fringes (particularly, interference fringes with the spacers 20) are less likely to occur as compared with the case where the conductor portion is configured in a straight line in both directions as shown in FIG.

  The discharge electrode 64 shown in FIG. 8 is provided with a plurality of rectangular openings 66, for example, squares, arranged at regular intervals in the vertical and horizontal directions. Therefore, a lattice-like conductor portion 68 extending in two directions perpendicular to each other is formed between the openings 66. The size of the opening 66 is, for example, within a range of 0.5 to 2.5 (mm) on one side, for example, about 1.5 (mm). The mutual distance between the openings 66, that is, the width and thickness of the conductor 68 are the same as those of the conductor 50 and the like. Also in this embodiment, the aperture ratio is about 90 to 99 (%), for example.

  The discharge electrode 70 shown in FIG. 9 has strip-shaped openings 72 provided in parallel with each other at a constant interval, and a plurality of conductor portions 74 are formed between them. That is, although it is configured in the same manner as the discharge electrode 52 shown in FIG. 6, a rectangular frame-shaped bus electrode 76 is provided outside the conductor portion 74, and all the conductor portions 74 are at both ends thereof. It is different in that it is connected to the bus electrode 76. The discharge electrodes 52 may be individually connected to an external circuit. However, if the discharge electrodes 52 are connected in this way, handling becomes easy.

  The discharge electrode 78 shown in FIG. 10 is provided with a plurality of regular hexagonal openings 80 arranged side by side, and is configured in substantially the same manner as the discharge electrode 46 shown in FIG. The arrangement direction S of the openings 80 in the vertical direction is different from that in the vertical direction. In this configuration, when the spacer 20 is provided so as to extend along the vertical direction in FIG. 10, the arrangement direction S of the openings 80 is inclined with respect to the longitudinal direction. In addition to the arrangement direction S, the openings 80 are arranged along two directions forming 60 degrees and -60 degrees, and these arrangement directions are also inclined with respect to the longitudinal direction of the spacer 20. ing. Therefore, compared to the discharge electrode 46, there is an advantage that the generation of interference fringes with the long spacer 20 is suppressed.

  As mentioned above, although this invention was demonstrated in detail with reference to drawings, this invention can be implemented also in another aspect, A various change can be added in the range which does not deviate from the main point.

It is a top view for demonstrating the structure of the flat type discharge lamp of one Example of this invention. It is a figure explaining the structure of a planar discharge lamp in the AA cross section in FIG. It is a figure which expands and shows the left end part of FIG. It is a figure which shows the electrode shape provided on the front plate of the flat type discharge lamp of FIG. It is a figure which expands a part of Drawing 4 and shows the size of each part of an electrode. It is a figure corresponding to FIG. 4 which shows the structural example of the front side electrode of the other Example of this invention. It is a figure corresponding to FIG. 4 which shows the structural example of the front side electrode of further another Example of this invention. It is a figure corresponding to FIG. 4 which shows the structural example of the front side electrode of further another Example of this invention. It is a figure corresponding to FIG. 4 which shows the structural example of the front side electrode of further another Example of this invention. It is a figure corresponding to FIG. 4 which shows the structural example of the front side electrode of further another Example of this invention.

Explanation of symbols

10: Planar discharge lamp, 12: Back plate, 14: Front plate, 46: Discharge electrode, 48: Opening, 50: Conductor

Claims (6)

A front plate having translucency, a back plate forming a flat airtight space between the front plate, and facing each other on the front plate and the back plate to generate discharge in the airtight space; A flat type discharge lamp comprising a front side electrode and a back side electrode provided so as to be covered with a dielectric layer, and emitting light generated by discharging in the airtight space through the front plate,
A narrow width formed by providing a plurality of openings of a predetermined shape with an area ratio in the range of 90 to 99 (%) of the total area with a constant mutual interval in the range of 15 to 50 (μm). A flat type discharge lamp characterized in that the front side electrode is constituted by a conductor film having a conductor part having a uniform and repeating shape.   2. The flat discharge lamp according to claim 1, wherein the conductor film has a mesh shape.   Each of the plurality of openings has a regular hexagonal shape with a diameter of an inscribed circle in a range of 0.5 to 2.5 (mm), and the conductor film has the conductor portion having a certain width dimension. 2. The flat discharge lamp according to claim 1, wherein the flat discharge lamp has a honeycomb shape as a whole by being bent along the outer peripheral edges of the plurality of openings.   Each of the plurality of openings has a rectangular shape with a short side having a size within a range of 0.5 to 2.5 (mm), and the conductor film has the plurality of openings with a certain width dimension. 2. The flat discharge lamp according to claim 1, wherein the flat discharge lamp is formed in a lattice shape or a ridge shape as a whole by being provided along the outer peripheral edge of the portion.   2. The flat discharge lamp according to claim 1, wherein the conductor portion has a plurality of linear portions extending along one direction and arranged at a mutual interval within a range of 0.5 to 2 (mm). A plurality of longitudinal spacers extending along a predetermined direction between the front plate and the back plate,
6. The flat discharge lamp according to claim 1, wherein the plurality of openings are arranged along a direction inclined at a predetermined angle of less than 90 degrees with respect to a longitudinal direction of the spacer.

Images