JP2010205640A - External electrode type rare gas fluorescent lamp, and rare gas fluorescent lamp unit for backlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outside electrode type rare gas fluorescent lamp (hereafter called as "fluorescent lamp") in which non-light-emitting region can be reduced and light-emission can be obtained in nearly all region of a lamp axial direction, and to provide a rare gas fluorescent lamp unit for backlight in which light adjustment in the lamp axial direction is possible, display devices like liquid crystal can be illuminated by uniform light without unevenness, and down-sizing can be promoted. <P>SOLUTION: The fluorescent lamp is formed with a pair of outside electrodes deployed on the outer face of a glass bulb that is coated with phosphor on the inner face, and a prescribed amount of rare gas is sealed in the inside, and a start electrode is installed in the inside of the glass bulb in a state that at least a part thereof is covered with the phosphor, and a starting position is exposed. The lamp unit is constituted in which a plurality pieces of the fluorescent lamps are arranged two-dimensionally in parallel so that lamp center axes are mutually extended parallel, and a plurality pieces of fluorescent lamps of the mutually same position in the lamp tube axis direction are connected to the common drive circuit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an external electrode type rare gas fluorescent lamp and a rare gas fluorescent lamp unit for a backlight, which are used as a light source of a backlight device such as a liquid crystal display device.

For example, a cold cathode fluorescent lamp (CCFL) is widely used as a light source for a backlight of a liquid crystal display panel because high luminance and efficient light emission can be obtained.
Some types of cold cathode fluorescent lamps have a straight tube bulb with a fluorescent coating on the inner surface, and a pair of electrodes are arranged opposite to each other in the tube axis direction in the bulb, and a small amount of mercury is contained. The phosphor is made to emit light by ultraviolet rays generated from mercury encapsulated and excited by discharge. For example, a plurality of phosphors are arranged two-dimensionally in parallel so that the central axes of the lamps extend parallel to each other. Thus, a backlight lamp unit is configured.

  Thus, in general, the screen brightness of a liquid crystal display panel or the like can be adjusted to an appropriate size according to the ambient brightness, user preference, image information, and the like. Is adjusted by light control on the backlight light source side (local dimming (hereinafter referred to as “LD”)).

When the screen brightness of a liquid crystal display panel or the like is adjusted by an LD, the backlight lamp unit is required to have a configuration capable of performing light control in the axial direction of the lamp.
However, for example, in a lamp unit in which a plurality of cold cathode fluorescent lamps are arranged in parallel, it is necessary for the cold cathode fluorescent lamp to discharge over the entire axial direction in the discharge space. Since it cannot be divided, there is a problem that light control in the lamp axis direction cannot be performed.
In order to solve such a problem, it is conceivable to divide the discharge by providing an external electrode at a position in the middle between the electrodes on the outer surface of the bulb. Problems such as opening a hole in the tube will occur.

On the other hand, from the viewpoint of environmental protection, as a new backlight light source that does not contain mercury, replacing cold cathode fluorescent lamps, for example, a plurality of strip-shaped electrodes are arranged on the outer surface of a glass bulb, and these electrodes are attached to these electrodes. An external electrode type rare gas fluorescent lamp that is lit by applying a high-frequency high voltage has been proposed (see, for example, Patent Document 1).
In this external electrode type rare gas fluorescent lamp, an easily startable portion for assisting the start of the lamp is formed, for example, by applying a conductive material inside the end portion of the glass bulb.

  As such a backlight lamp unit using an external electrode type rare gas fluorescent lamp, for example, a plurality of (for example, four) lamps supported at both ends are extended in parallel at positions spaced apart from each other. The thing of the structure arrange | positioned is proposed (for example, refer patent document 2).

However, even in such a backlight lamp unit using a rare gas fluorescent lamp, there is a problem that light control in the lamp axis direction cannot be performed.
Further, in the rare gas fluorescent lamp equipped with the above-mentioned easy-starting conductive material, a phosphor is provided in the range where the easy-starting conductive material is provided in order to prevent the starting voltage from increasing. As a result, no light is emitted in the vicinity of the easily-starting conductive material. As a result, a low-luminance portion is likely to be generated, and each lamp does not emit light other than the light-emitting region where a predetermined light output can be obtained. The area becomes larger. Therefore, when the backlight unit is configured, there is a problem that it is difficult to illuminate a display device such as a liquid crystal evenly with uniform light, and in order to reduce unevenness in emission intensity, It is necessary to increase the separation distance from the lamp to the diffusion plate positioned on the front side in the light irradiation direction, and there is a problem that the entire unit is increased in size.

JP-A-10-188910 JP 2007-109492 A

As described above, in a backlight unit using a cold cathode fluorescent lamp or an external electrode type rare gas fluorescent lamp, since dimming in the lamp axis direction cannot be performed, for example, dimming is performed by dividing the vertical direction of the liquid crystal screen. (LD control) was actually performed.
Furthermore, in a lamp unit using an external electrode type rare gas fluorescent lamp, in each lamp, a low-luminance portion is generated in the peripheral portion of the easily-starting conductive material, so that a display device such as a liquid crystal can be displayed uniformly with uniform light. There is a problem that it is difficult to illuminate.

The present invention has been made on the basis of the above circumstances, and is an external electrode type noble gas capable of reducing the size of the non-light emitting region and obtaining light emission over substantially the entire region in the lamp axis direction. An object is to provide a fluorescent lamp.
Another object of the present invention is to perform light control in the lamp axis direction. For example, a display device such as a liquid crystal can be illuminated uniformly with uniform light, and can be configured as a compact one. The object is to provide a rare gas fluorescent lamp unit for backlight.

The external electrode type rare gas fluorescent lamp of the present invention includes a straight tubular glass bulb having an inner surface coated with a phosphor, a pair of external electrodes disposed opposite to each other on the outer surface of the glass bulb, and the glass bulb. In an external electrode type rare gas fluorescent lamp comprising a starting electrode disposed on the inner surface of a glass bulb and having a predetermined amount of rare gas sealed inside a glass bulb,
The starting electrode is characterized in that at least a part of the starting electrode is covered with the phosphor, and a starting point that intersects with the external electrode is exposed across the tube wall of the glass bulb.

The external electrode type rare gas fluorescent lamp of the present invention comprises a straight tubular glass bulb having an inner surface coated with a phosphor, and a pair of external electrodes disposed opposite to each other on the outer surface of the glass bulb, In an external electrode type rare gas fluorescent lamp in which a predetermined amount of rare gas is sealed inside a glass bulb,
At least one external electrode of the pair of external electrodes is composed of a plurality of divided electrode groups divided in the tube axis direction of the glass bulb, and at a position corresponding to each divided electrode on the inner surface of the glass bulb. A starting electrode is arranged,
Each of the starting electrodes is covered with at least a part of the phosphor, and a starting point that intersects with the external electrode across the tube wall of the glass bulb is exposed.

Noble gas fluorescent lamp unit for backlight of the present invention, a plurality of the above external electrode type rare gas fluorescent lamps are two-dimensionally arranged in parallel,
A plurality of external electrode type rare gas fluorescent lamps at the same position in the tube axis direction of the glass bulb are connected to a common drive circuit.

Noble gas fluorescent lamp unit for backlight of the present invention, a plurality of the above external electrode type rare gas fluorescent lamps are two-dimensionally arranged in parallel,
In each of the external electrode type rare gas fluorescent lamps, the divided electrodes at the same position in the tube axis direction of the glass bulb are connected to a common drive circuit.

  According to the external electrode type rare gas fluorescent lamp of the first aspect, the portion of the starting electrode excluding the starting portion is covered with the phosphor layer, so that the size of the non-light emitting region is reduced without reducing the lamp starting property. Therefore, the light emission can be obtained over substantially the entire area in the lamp axis direction.

  According to the external electrode type rare gas fluorescent lamp according to claim 2, basically, one of the pair of external electrodes is constituted by the divided electrode group, so that the illuminance distribution in the lamp axis direction can be arbitrarily set. In addition, since the portion excluding the starting point in the starting electrode is covered with the phosphor layer, the size of the non-light-emitting region can be reduced as much as possible without deteriorating the lamp starting property. Therefore, it is possible to obtain light emission over substantially the entire region in the lamp axis direction.

  According to the noble gas fluorescent lamp unit for backlight according to claim 3, lighting control is performed by using a plurality of external electrode type noble gas fluorescent lamps arranged in the same position in the tube axis direction of the glass bulb as one unit unit. Since it is configured to be able to perform dimming in the lamp axis direction of the type rare gas fluorescent lamp, for example, a display device such as a liquid crystal can be illuminated uniformly with uniform light, and the individual external electrode type Since the rare gas fluorescent lamp is configured so that the non-light-emitting region becomes as small as possible, a diffuser plate positioned in front of the lamp group in the light irradiation direction is disposed close to the lamp group. Therefore, it is possible to reduce the size of the lamp unit.

  According to the noble gas fluorescent lamp unit for backlight according to claim 4, in the plurality of external electrode type noble gas fluorescent lamps, the light emitting region related to the divided electrodes arranged at the same position in the tube axis direction of the glass bulb is one unit. Since it is configured to be able to perform light control in the lamp axis direction of the external electrode type rare gas fluorescent lamp by controlling lighting as a unit, a display device such as a liquid crystal can be illuminated uniformly with uniform light, for example. In addition, since each of the external electrode type rare gas fluorescent lamps is configured so that the non-light-emitting region becomes as small as possible, the diffuser plate positioned on the front side in the light irradiation direction of the lamp group is used as the lamp group. Therefore, it is possible to reduce the size of the lamp unit.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the outline of a structure in an example of the external electrode type | mold rare gas fluorescent lamp of this invention, Comprising: (a) Sectional drawing which shows the cross section along a lamp | ramp central axis, (b) AA line in (a) FIG. 6 is an end view taken along line B-B in FIGS. It is a graph which shows the measurement result of the luminance distribution in the edge part area | region in the side by which the starting electrode was arrange | positioned of the external electrode type rare gas fluorescent lamp produced in the experiment example. It is explanatory drawing which shows the outline of the structure in the other example of the external electrode type | mold rare gas fluorescent lamp of this invention, Comprising: (a) Sectional drawing which shows the cross section along a lamp central axis, (b) D- in (a) It is an end view in the D line, and is an end view in the EE line in (c) and (a). It is explanatory drawing which shows the outline of a structure in an example of the noble gas fluorescent lamp unit for backlights of this invention using the external electrode type rare gas fluorescent lamp shown in FIG. FIG. 5 is a block diagram schematically showing a part of a configuration example of a lamp lighting device in the rare gas fluorescent lamp unit shown in FIG. 4. It is explanatory drawing which shows the outline of a structure in the other example of the noble gas fluorescent lamp unit for backlights of this invention using the external electrode type rare gas fluorescent lamp shown in FIG. It is a block diagram which shows roughly a part in one structural example of the lamp lighting device in the noble gas fluorescent lamp unit shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail.

[External electrode type rare gas fluorescent lamp]
An external electrode type rare gas fluorescent lamp according to the present invention includes a straight tubular glass bulb having an inner surface coated with a phosphor, a pair of external electrodes disposed opposite to each other on the outer surface of the glass bulb, and an inner surface of the glass bulb. And a starting electrode disposed in the glass bulb, and a predetermined amount of a rare gas is sealed inside the glass bulb.

<First Embodiment>
FIG. 1 is an explanatory diagram showing an outline of the configuration of an example of an external electrode type rare gas fluorescent lamp according to the present invention, wherein (a) a sectional view showing a section along the central axis of the lamp, and (b) in (a). It is an end view in an AA line, and is an end view in a BB line in (c) and (a).
This external electrode type rare gas fluorescent lamp (hereinafter, simply referred to as “rare gas fluorescent lamp”) 10 has a straight tubular glass bulb 11 sealed at both ends and an outer surface of the glass bulb 11 facing each other. In a state, a pair of external electrodes 15A and 15B formed so as to extend along the tube axis (lamp central axis) C of the glass bulb, and a starting electrode 18 formed in one end region in the glass bulb 11 In addition, a rare gas is sealed in the glass bulb 11.

The glass bulb 11 is made of, for example, quartz glass, lead glass, soda lime glass, borosilicate glass, aluminosilicate glass, barium glass, and the like, and the phosphor layer 12 is formed over substantially the entire inner surface thereof.
The phosphor layer 12 is formed by applying a phosphor that emits visible light to the inner surface of the glass bulb 11 and baking it.
Specific examples of the phosphor include, for example, (Y, Gd) BO ₃ : Eu or Y ₂ O ₃ : Eu as a red phosphor, LaPO ₄ : Ce, Tb as a green phosphor, and BaMgAl as a blue phosphor. ₁₀ O ₁₇ : Eu can be exemplified, but the phosphor is not limited thereto.

The external electrodes 15A and 15B are configured by screen-printing and baking a conductive paste such as silver paste at positions facing each other across the lamp central axis C on the outer surface of the glass bulb 11. 15A is a high voltage side electrode, and the other external electrode 15B is a low voltage side electrode. In addition, the external electrodes 15A and 15B may be configured, for example, by pasting a strip-shaped aluminum tape cut to the outer surface of the glass bulb 11.
The external electrodes 15A and 15B are not shown, but one end thereof is electrically connected to a power supply terminal made of a metal having good conductivity through a lead. It is covered with a protective film formed by baking glass paste.

  As the rare gas sealed in the glass bulb 11, for example, xenon gas or a mixed gas of xenon and other rare gas can be exemplified, and the sealed amount is, for example, 13 kPa (100 Torr).

As described above, one end region on the inner surface of the glass bulb 11, specifically, for example, in one place having the least influence in relation to the light extraction efficiency during lamp lighting, for example, a conductive material such as carbon paste. An arc-shaped or ring-shaped starter electrode 18 made of an active substance is provided, and is capacitively coupled to the pair of external electrodes 15A and 15B.
The starting electrode 18 is formed, for example, by applying a paste-like conductive material on the inner surface of the glass bulb 11 and firing it. In this embodiment, the starting electrode 18 has a cross section perpendicular to the lamp central axis C ( In FIG. 1 (b)), one valve inner surface region located between the pair of external electrodes 15A and 15B extends in the circumferential direction so that both ends intersect with each of the pair of external electrodes 15A and 15B. It is provided to extend in the circumferential direction beyond the edge of the valve inner surface region corresponding to the valve outer surface region where the external electrode is disposed.

  Thus, the starting electrode 18 in the rare gas fluorescent lamp 10 is covered at least in part by the phosphor layer 12 and starts crossing the external electrodes 15A and 15B across the tube wall of the glass bulb 11. The part 18A is exposed.

  Therefore, by applying a high-frequency voltage between the pair of external electrodes 15A and 15B, a so-called preliminary discharge is generated in a portion where the starting electrode 18 is provided in the internal space of the glass bulb 11, and then a noble gas is chained. The fluorescent material is excited by ultraviolet rays radiated by the discharge generated by the discharge, and the visible light is radiated to the outside of the glass bulb 11. Since the portion excluding the portion is covered with the phosphor layer 12 and the phosphor layer 12 is provided up to the end region where the starting electrode 18 is located, the rare gas fluorescent lamp 10 having the above-described configuration is used. For example, in the case of a conventional rare gas fluorescent lamp, sufficient light emission can be obtained even in the end region where the starting electrode 18 is provided as a non-light emitting region. Runode, without reducing the lamp starting performance, it is possible to obtain light emission over substantially the entire area in the axial direction can be reduced the size of the non-light-emitting region as much as possible.

Hereinafter, experimental examples performed for confirming the effects of the present invention will be described.
A rare gas fluorescent lamp according to the present invention was produced according to the configuration shown in FIG. The specific configuration of this rare gas fluorescent lamp is as follows.
[Configuration of rare gas fluorescent lamp (10)]
Glass bulb (11): material: borosilicate glass, outer diameter 10 mm, total length 190 mm,
External electrode (15A, 15B): material: silver paste, total length: 190 mm, width: 0.5 mm,
Starting electrode (18): forming position: position 5 mm inward in the axial direction from the end wall of the glass bulb, width: about 1 mm, length (circumferential direction) 20 mm, exposed portion length (starting position): about 5 mm is there. Phosphor layer (12): thickness; 15 μm,
Luminescent gas: Xenon gas, enclosed amount: 13 kPa

  Further, a comparative rare gas fluorescent lamp having the same configuration as that described above was prepared except that the entire starting electrode was exposed.

Each of the rare gas fluorescent lamp according to the present invention and the comparative rare gas fluorescent lamp is turned on by applying a high frequency voltage having a frequency of 50 kHz and a peak voltage of 1700 V between the external electrodes, and the side on which the starting electrode is disposed. The luminance in the edge region of the was measured. The results are shown in FIG. In FIG. 2, the vertical axis represents the relative luminance when the luminance of the central portion in the lamp axis direction is 100%, and the horizontal axis is the distance in the lamp axis direction from the end wall on the side where the starting electrode is disposed. Yes, (a) shows the results of the rare gas fluorescent lamp according to the present invention, and (b) shows the results of the comparative rare gas fluorescent lamp.
As is apparent from the results, according to the rare gas fluorescent lamp of the present invention, the luminance of the end region in the lamp axis direction is lower than that of the central portion, but is higher than that of the comparative rare gas fluorescent lamp. It was confirmed that luminance was obtained. Therefore, for example, when a backlight unit is configured, it is considered that occurrence of luminance unevenness in the lamp axis direction can be reduced.

<Second Embodiment>
FIG. 3 is an explanatory view showing an outline of the configuration of another example of the external electrode type rare gas fluorescent lamp of the present invention, wherein (a) a sectional view showing a section along the central axis of the lamp, (b) ( It is the end elevation in the DD line in a), (c) It is the end elevation in the EE line in (a).
In the rare gas fluorescent lamp 20, in the rare gas fluorescent lamp (FIG. 1) of the first embodiment, at least one of the pair of external electrodes 15A and 15B is divided with respect to the axial direction of the rare gas fluorescent lamp 20. The first embodiment described above except that the starting electrode 18 is arranged at a position corresponding to each of the divided electrodes on the inner surface of the glass bulb 11 and is constituted by a plurality of divided electrode groups. It has the same configuration as the rare gas fluorescent lamp 10 according to the embodiment. In FIG. 3, the same components as those of the rare gas fluorescent lamp shown in FIG.

In this rare gas fluorescent lamp 20, for example, the other external electrode 15B, which is a low-voltage side electrode, is a divided electrode formed, for example, at positions where four divided electrodes 16A to 16D are spaced apart at equal intervals in the lamp axis direction. It is composed of groups.
The separation distance L between the adjacent divided electrodes is preferably set to, for example, 5 to 15 mm in order to suppress the size of the non-light emitting region while preventing the occurrence of creeping discharge between the divided electrodes.
In addition, the number of divided electrodes is not limited to four, and can be set as appropriate according to the purpose. However, it is about 4 to 12 for the purpose of minimizing the wiring on the mounting. Is desirable.

Each of the divided electrodes 16A to 16D constituting the one external electrode 15A and the other external electrode 15B is not shown, but one end thereof serves as a power supply terminal made of a metal having good conductivity via a lead. Therefore, the illuminance distribution in the lamp axis direction can be arbitrarily set by appropriately adjusting the voltage applied between the one external electrode 15A and each of the divided electrodes 16A to 16D. It is configured to be able to.
Further, the part other than the power feeding part is covered with a protective film formed by baking glass paste, for example.

  Each starting electrode 18 is formed, for example, at a position on one end side in the valve inner surface region corresponding to the valve outer surface region in which each divided electrode 16A to 16D is disposed. It is preferable that the electrodes 16A to 16D are formed at a position within a range of 5 to 10 mm from the one end edge position of the electrodes 16A to 16D.

  Each starting electrode 18 is, for example, in the circumferential direction over the entire region of one bulb inner surface region located between the pair of external electrodes 15A and 15B in a cross section perpendicular to the lamp central axis C (see FIG. 3B). It is provided to extend in the circumferential direction beyond the edge of the valve inner surface region corresponding to the valve outer surface region where the external electrode is disposed so that both ends intersect each of the pair of external electrodes 15A, 15B. , At least a part of which is covered with the phosphor layer 12 and crossing each of the divided electrodes 16A to 16D constituting the one external electrode 15A and the other external electrode 15B across the tube wall of the glass bulb 11 The part 18A is exposed.

  Thus, according to the rare gas fluorescent lamp 20 having the above-described configuration, basically, one of the pair of external electrodes 15A and 15B is configured by the group of divided electrodes 16A to 16D. In addition, since the portion excluding the starting portion 18A of the starting electrode 18 is covered with the phosphor layer 12, a conventional rare gas fluorescent lamp can be set as a non-light emitting region. Even in the region where the starting electrode 18 is provided, sufficient light emission can be obtained, so that the size of the non-light emitting region can be made as small as possible without degrading the lamp starting property, and therefore Light emission can be obtained over substantially the entire axial direction.

The external electrode type rare gas fluorescent lamp as described above is useful as a light source of a backlight device such as a liquid crystal display device as described above.
Hereinafter, the rare gas fluorescent lamp unit for backlight of the present invention will be described.

[Noble gas fluorescent lamp unit for backlight]
<First Embodiment>
FIG. 4 is an explanatory diagram showing an outline of the configuration of an example of the rare gas fluorescent lamp unit for backlight of the present invention using the external electrode type rare gas fluorescent lamp shown in FIG. 1, and FIG. It is a block diagram which shows roughly a part in one structural example of the lamp lighting device in a gas fluorescent lamp unit.
In this rare gas fluorescent lamp unit for backlight (hereinafter, simply referred to as “lamp unit”), a plurality of the external electrode type rare gas fluorescent lamps 10 according to the first embodiment are arranged in the lamp central axis direction (FIG. 4). For example, four lamps are aligned in the state where the positions of the lamp center axes coincide with each other, and nine lamps are parallel to the lamp center axis in a direction perpendicular to the lamp center axis (vertical direction in FIG. 4). The light irradiation area LA that is two-dimensionally arranged in parallel (arranged) so as to be aligned in a state where the light amount should be uniformed by light control by the LD is, for example, 4 in the lamp central axis direction. In addition, when divided into a total of 12 regions (hereinafter referred to as “LD control unit regions”) Z1 to Z12 in the direction perpendicular to the lamp central axis, Light is emitted from a plurality of, for example, three rare gas fluorescent lamps 10 adjacent to each other (arranged in a direction perpendicular to the lamp central axis) arranged at the same position in the axial direction. .

  The lamp lighting device that lights each rare gas fluorescent lamp 10 includes three rare gas fluorescent lamps 10 that irradiate one LD control unit region with respect to each of the plurality of LD control unit regions Z1 to Z12. A common drive circuit (LD control circuit) 30 for controlling lighting as one unit unit is provided, and each drive circuit 30 has a high-frequency voltage (between the external electrodes 15A and 15B of each rare gas fluorescent lamp 10). The rare gas fluorescent lamp 10 is turned on by applying a rectangular wave voltage.

  Each drive circuit 30 is connected in parallel to each of the other external electrodes 15B of, for example, three rare gas fluorescent lamps 10 that emit light to one LD control unit region on the output side, and an inverter circuit on the input side. A transformer 31 connected to 32, and a DC voltage of several tens to several hundreds V supplied from a DC power supply (not shown) is converted into an AC voltage by an inverter circuit 32, and a switching element such as an FET, for example Is controlled by switching a high frequency voltage (for example, a rectangular wave) to the transformer 31, boosted by the transformer 31, and applied to each rare gas fluorescent lamp 10. Here, one external electrode 15A in each rare gas fluorescent lamp 10 is connected to GND.

  In addition, the lamp lighting device includes an image information acquisition unit 36 that acquires image information S related to screen brightness, and an image signal processing unit that performs appropriate signal processing on the acquired image information S and outputs an image signal. 37 and a control circuit 35 including a control signal generator 38 that determines the brightness of each of the LD control regions Z1 to Z12 based on the image signal and outputs a dimming control signal to the inverter circuit 32. .

  In this lamp unit, dimming of each LD control region Z1 to Z12 by three rare gas fluorescent lamps 10 at the same position in the lamp central axis direction, specifically, for example, each LD control is performed by the control circuit 35. A dimming control signal output according to the brightness of the screen area corresponding to the areas Z1 to Z12 is output to the inverter circuit 32, and dimming or blinking (duty dimming) in the dynamic range is performed for each LD control. This is performed for each of the unit areas Z1 to Z12, and thereby LD is executed.

When a specific configuration example of the lamp unit is shown, for example, when the screen size is for a backlight of an LCD display device corresponding to 32 type, the total length of each rare gas fluorescent lamp 10 is, for example, 190 mm, The arrangement pitch of the rare gas fluorescent lamp 10 in the lamp central axis direction is, for example, 10 mm, and the arrangement pitch in the direction perpendicular to the lamp central axis is, for example, 45 mm.
In the lamp unit, the light emitted from each rare gas fluorescent lamp 10 is applied to, for example, a display device through a diffusion plate, a directivity control sheet, a diffusion sheet, and the like. The separation distance between the plane on which the lamp central axis of the fluorescent lamp 10 is located and the diffusion plate is, for example, 20 to 30 mm.

  Thus, according to the lamp unit configured as described above, lighting control is performed by controlling lighting of the three rare gas fluorescent lamps 10 adjacent to each other aligned in the direction perpendicular to the lamp central axis of the rare gas fluorescent lamp 10 as one unit unit. Since it is configured to be able to perform light control in the axial direction, a display device such as a liquid crystal can be illuminated uniformly with uniform light, and each noble gas fluorescent lamp 10 has a non-light emitting region. Since the lamp unit is made of a conventional external electrode type rare gas fluorescent lamp, since it is configured to be as small as possible, each rare gas fluorescent lamp 10 that has a size of, for example, about 35 mm is required. The distance between the plane on which the lamp central axis is located and the diffusion plate is reduced to, for example, 25 mm, that is, the diffusion plate is arranged close to the lamp group. Bets can be, therefore, it is possible to reduce the size of the lamp unit.

<Second Embodiment>
FIG. 6 is an explanatory diagram showing an outline of the configuration of another example of a rare gas fluorescent lamp unit for backlight of the present invention using the external electrode type rare gas fluorescent lamp shown in FIG. 3, and FIG. It is a block diagram which shows roughly a part in one structural example of the lamp lighting device in the rare gas fluorescent lamp unit shown.
In this rare gas fluorescent lamp unit (lamp unit) for backlight, a plurality of, for example, nine of the external electrode type rare gas fluorescent lamps 20 according to the second embodiment are arranged with their lamp central axes extending in parallel with each other. Two light irradiation areas LA that are two-dimensionally arranged in parallel (to be arranged side by side) and whose light quantity should be made uniform by light control by LD are, for example, four in the lamp central axis direction and perpendicular to the lamp central axis. When divided into a total of 12 LD control unit regions Z1 to Z12 with respect to a specific direction, the center of a plurality of, for example, three rare gas fluorescent lamps 20 adjacent to each other for one LD control unit region The light is emitted from the light emitting regions related to the divided electrodes arranged at the same position in the axial direction.

  The lamp lighting device for lighting each rare gas fluorescent lamp 20 has the same basic configuration as that shown in FIG. 5, and one LD control unit region for each of the plurality of LD control unit regions Z1 to Z12. A common drive circuit (LD control circuit) 30 for controlling the lighting of the light-emitting areas of the divided electrodes in the three rare gas fluorescent lamps 10 that irradiate the light as one unit unit, and obtaining image information A control circuit 35 having a unit 36, an image signal processing unit 37, and a control signal generating unit 38 is provided.

  Each drive circuit 30 applies a high-frequency voltage (rectangular wave voltage) between the divided electrodes constituting one external electrode 15A and the other external electrode 15B of each rare gas fluorescent lamp 20 to thereby generate the rare gas fluorescent lamp 10. Are connected in parallel to the divided electrodes 16A (16B to 16D) in each of, for example, the three rare gas fluorescent lamps 20 that irradiate light to one LD control unit region. A transformer 31 having an input side connected to an inverter circuit 32 is provided, and a DC voltage of several tens to several hundreds V supplied from a DC power supply (not shown) is converted into an AC voltage by the inverter circuit 32. By switching the switching element such as a high frequency voltage (for example, a rectangular wave) is input to the transformer 31 and boosted by the transformer 31 Is configured to be applied to each of the rare gas fluorescent lamps 20. Here, one external electrode 15A in each rare gas fluorescent lamp 20 is connected to GND.

  Also in this lamp unit, in each of the three rare gas fluorescent lamps 20 adjacent to each other, dimming of the LD control regions Z1 to Z12 by the divided electrodes 16A (16B to 16D) at the same position in the lamp central axis direction, Specifically, for example, a dimming control signal output according to the brightness of the screen area corresponding to each of the LD control areas Z1 to Z12 is output to the inverter circuit 32 by the control circuit 35, and the dynamic range is adjusted. Dimming or blinking (duty dimming) is performed for each of the LD control unit areas Z1 to Z12, whereby LD is executed.

When a specific configuration example of the lamp unit is shown, for example, when the screen size is for a backlight of an LCD display device corresponding to 32 type, the total length of each rare gas fluorescent lamp 20 is, for example, 780 mm, an outer diameter. Is, for example, 10 mm, the total length of each of the divided electrodes 16A to 16D is, for example, 180 mm, the separation distance between the adjacent divided electrodes is 10 mm, and the arrangement pitch of the rare gas fluorescent lamps 20 is, for example, 45 mm.
In the lamp unit, the distance between the plane where the lamp central axis of each rare gas fluorescent lamp 20 is located and the diffusion plate is, for example, 20 to 30 mm.

  Thus, according to the lamp unit having the above-described configuration, the divided electrodes at the same position in the lamp central axis direction in each of the three rare gas fluorescent lamps 10 adjacent to each other are controlled to be turned on as a unit unit. Since it is configured to be able to perform light control in the axial direction, a display device such as a liquid crystal can be illuminated uniformly with uniform light, and each noble gas fluorescent lamp 20 has a non-light emitting region. Since the lamp unit is made of a conventional external electrode type rare gas fluorescent lamp, since it is configured to be as small as possible, each rare gas fluorescent lamp 10 that has a size of, for example, about 35 mm is required. The distance between the plane on which the lamp central axis is located and the diffusion plate is reduced to, for example, 25 mm, that is, the diffusion plate is brought close to the lamp group. Can be arranged Te, therefore, it is possible to reduce the size of the lamp unit.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, the external electrode type rare gas fluorescent lamp according to the first embodiment of the present invention is not limited to the configuration in which the starting electrode is provided at one end region.
The number and arrangement pattern of the rare gas fluorescent lamps constituting the rare gas fluorescent lamp unit of the present invention are not limited to the above configuration, and the number of LD control unit areas to be set and the lamp lighting device The configuration is not particularly limited.

DESCRIPTION OF SYMBOLS 10 External electrode type rare gas fluorescent lamp 11 Glass bulb 12 Phosphor layer 15A One external electrode 15B The other external electrode 16A-16D Split electrode 18 Starting electrode 18A Starting part 20 Noble gas fluorescent lamp 30 Drive circuit (LD control circuit)
31 Transformer 32 Inverter circuit 35 Control circuit 36 Image information acquisition unit 37 Image signal processing unit 38 Control signal generation unit C Glass bulb tube axis (lamp central axis)
LA light irradiation area Z1 to Z12 LD control unit area S Image information

Claims (4)

A straight tubular glass bulb having an inner surface coated with a phosphor, a pair of external electrodes disposed opposite to each other on the outer surface of the glass bulb, and a starting electrode disposed on the inner surface of the glass bulb In the external electrode type rare gas fluorescent lamp in which a predetermined amount of rare gas is sealed inside the glass bulb,
The starting electrode is covered with the phosphor and is exposed to a starting portion that intersects with the external electrode across the tube wall of the glass bulb. lamp. Equipped with a straight tubular glass bulb coated with phosphor on the inner surface and a pair of external electrodes arranged opposite to each other on the outer surface of the glass bulb. A predetermined amount of rare gas is enclosed inside the glass bulb. In the external electrode type rare gas fluorescent lamp,
At least one external electrode of the pair of external electrodes is composed of a plurality of divided electrode groups divided in the tube axis direction of the glass bulb, and at a position corresponding to each divided electrode on the inner surface of the glass bulb. A starting electrode is arranged,
Each of the starting electrodes is covered with at least a part of the phosphor, and an external electrode type that exposes a starting portion that intersects with the external electrode across the tube wall of the glass bulb is exposed. Noble gas fluorescent lamp. A plurality of external electrode type rare gas fluorescent lamps according to claim 1 are two-dimensionally arranged in parallel,
A rare gas fluorescent lamp unit for backlight, wherein a plurality of external electrode type rare gas fluorescent lamps at the same position in the tube axis direction of the glass bulb are connected to a common drive circuit. A plurality of external electrode type rare gas fluorescent lamps according to claim 2 are two-dimensionally arranged in parallel,
In each of the external electrode type rare gas fluorescent lamps, a divided electrode at the same position in the tube axis direction of the glass bulb is connected to a common drive circuit.

Images